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Abstract
In this perspective, we introduce shelterin and the mechanisms of ATM activation and NHEJ at telomeres, before discussing the following questions: How are t-loops proposed to protect chromosome ends and what is the evidence for this model? Can other models explain how TRF2 mediates end protection? Could t-loops be pathological structures? How is end protection achieved in pluripotent cells? What do the insights into telomere end protection in pluripotent cells mean for the t-loop model of end protection? Why might different cell states have evolved different mechanisms of end protection? Finally, we offer support for an updated t-loop model of end protection, suggesting that the data is supportive of a critical role for t-loops in protecting chromosome ends from NHEJ and ATM activation, but that other mechanisms are involved. Finally, we propose that t-loops are likely dynamic, rather than static, structures.
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Affiliation(s)
- Phil Ruis
- The Francis Crick Institute, London NW1 1AT, United Kingdom
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52
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Gupta S, Santoro R. Regulation and Roles of the Nucleolus in Embryonic Stem Cells: From Ribosome Biogenesis to Genome Organization. Stem Cell Reports 2020; 15:1206-1219. [PMID: 32976768 PMCID: PMC7724472 DOI: 10.1016/j.stemcr.2020.08.012] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 08/25/2020] [Accepted: 08/25/2020] [Indexed: 12/13/2022] Open
Abstract
The nucleolus is the largest compartment of the eukaryotic cell's nucleus. It acts as a ribosome factory, thereby sustaining the translation machinery. The nucleolus is also the subnuclear compartment with the highest transcriptional activity in the cell, where hundreds of ribosomal RNA (rRNA) genes transcribe the overwhelming majority of RNAs. The structure and composition of the nucleolus change according to the developmental state. For instance, in embryonic stem cells (ESCs), rRNA genes display a hyperactive transcriptional state and open chromatin structure compared with differentiated cells. Increasing evidence indicates that the role of the nucleolus and rRNA genes might go beyond the control of ribosome biogenesis. One such role is linked to the genome architecture, since repressive domains are often located close to the nucleolus. This review highlights recent findings describing how the nucleolus is regulated in ESCs and its role in regulating ribosome biogenesis and genome organization for the maintenance of stem cell identity.
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Affiliation(s)
- Shivani Gupta
- Department of Molecular Mechanisms of Disease, DMMD, University of Zurich, 8057 Zurich, Switzerland
| | - Raffaella Santoro
- Department of Molecular Mechanisms of Disease, DMMD, University of Zurich, 8057 Zurich, Switzerland.
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53
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Carmel-Gross I, Levy E, Armon L, Yaron O, Waldman Ben-Asher H, Urbach A. Human Pluripotent Stem Cell Fate Regulation by SMARCB1. Stem Cell Reports 2020; 15:1037-1046. [PMID: 33125876 PMCID: PMC7664050 DOI: 10.1016/j.stemcr.2020.10.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 10/01/2020] [Accepted: 10/02/2020] [Indexed: 02/07/2023] Open
Abstract
Epigenetic regulation by the SWI/SNF complex is essential for normal self-renewal capacity and pluripotency of human pluripotent stem cells (hPSCs). It has been shown that different subunits of the complex have a distinct role in this regulation. Specifically, the SMARCB1 subunit has been shown to regulate the activity of enhancers in diverse types of cells, including hPSCs. Here, we report the establishment of conditional hPSC lines, enabling control of SMARCB1 expression from complete loss of function to significant overexpression. Using this system, we show that any deviation from normal SMARCB1 expression leads to cell differentiation. We further found that SMARCB1 expression is not required for differentiation of hPSCs into progenitor cells, but rather for later stages of differentiation. Finally, we identify SMARCB1 as a critical player in regulation of cell-cell and cell-ECM interactions in hPSCs and show that this regulation is mediated at least in part by the WNT pathway.
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Affiliation(s)
- Ilana Carmel-Gross
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Etgar Levy
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Leah Armon
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Orly Yaron
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Hiba Waldman Ben-Asher
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel
| | - Achia Urbach
- The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel.
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54
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Liu QQ, Li CM, Fu LN, Wang HL, Tan J, Wang YQ, Sun DF, Gao QY, Chen YX, Fang JY. Enterotoxigenic Bacteroides fragilis induces the stemness in colorectal cancer via upregulating histone demethylase JMJD2B. Gut Microbes 2020; 12:1788900. [PMID: 32684087 PMCID: PMC7524313 DOI: 10.1080/19490976.2020.1788900] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The enrichment of Enterotoxigenic Bacteroides fragilis (ETBF) has been identified in CRC patients and associated with worse prognosis. Cancer stem cells (CSCs) play essential roles in CRC development. However, whether ETBF is involved in CSCs regulation is unknown. To clarify the role of ETBF in CSCs properties, we performed extreme limited dilution assays (ELDA) in nude mice injected with ETBF-treated or untreated CRC cells subcutaneously, tumor organoids culture in azoxymethane (AOM) mouse model after gavaging with or without ETBF, and cell sphere formation assay after incubating CRC cell lines with or without ETBF. The results indicated that ETBF increased the stemness of CRC cells in vivo and in vitro. Furthermore, ETBF enhanced the expression of core stemness transcription factors Nanog homeobox (NANOG) and sex determining region Y-box 2 (SOX2). Histone H3 Lysine 9 trimethylation (H3K9me3) is critical in regulating CSCs properties. As an epigenetic and transcriptional regulator, JmjC-domain containing histone demethylase 2B (JMJD2B) is essential for embryonic stem cell (ESC) transformation and H3K9me3 demethylation. Mechanistically, ETBF infection significantly upregulated JMJD2B levels in CRC cell lines and nude mice xenograft model. JMJD2B epigenetically upregulated NANOG expression via demethylating its promoter H3K9me3, to mediate ETBF-induced stemness of CRC cells. Subsequently, we found that the Toll-like receptor 4 (TLR4) pathway, activated by ETBF, contributed to the enhanced expression of JMJD2B via nuclear transcription factor nuclear factor of activated T cells 5 (NFAT5). Finally, in human CRC samples, the amount of ETBF positively correlated with nuclear NFAT5, JMJD2B, and NANOG expression levels. In summary, ETBF upregulated JMJD2B levels in a TLR4-NFAT5-dependent pathway, and played an important role in stemness regulation, which promoted colorectal carcinogenesis.
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Affiliation(s)
- Qian-Qian Liu
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, State Key Laboratory for Oncogenes and Related Genes, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Chun-Min Li
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, State Key Laboratory for Oncogenes and Related Genes, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Lin-Na Fu
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, State Key Laboratory for Oncogenes and Related Genes, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Hao-Lian Wang
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, State Key Laboratory for Oncogenes and Related Genes, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Juan Tan
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, State Key Laboratory for Oncogenes and Related Genes, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Yun-Qian Wang
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, State Key Laboratory for Oncogenes and Related Genes, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Dan-Feng Sun
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, State Key Laboratory for Oncogenes and Related Genes, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Qin-Yan Gao
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, State Key Laboratory for Oncogenes and Related Genes, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China,Qin-Yan Gao Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, State Key Laboratory for Oncogenes and Related Genes, Renji Hospital, School of Medicine, Shanghai Institute of Digestive Disease, Shanghai Jiao Tong University, Shanghai200001, China
| | - Ying-Xuan Chen
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, State Key Laboratory for Oncogenes and Related Genes, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China,CONTACT Xuan Chen
| | - Jing-Yuan Fang
- Division of Gastroenterology and Hepatology, Key Laboratory of Gastroenterology and Hepatology, Ministry of Health, State Key Laboratory for Oncogenes and Related Genes, Shanghai Institute of Digestive Disease, Renji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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55
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Paik S, Maule F, Gallo M. Dysregulation of chromatin organization in pediatric and adult brain tumors: oncoepigenomic contributions to tumorigenesis and cancer stem cell properties. Genome 2020; 64:326-336. [PMID: 33075237 DOI: 10.1139/gen-2020-0097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The three-dimensional (3D) organization of the genome is a crucial enabler of cell fate, identity, and function. In this review, we will focus on the emerging role of altered 3D genome organization in the etiology of disease, with a special emphasis on brain cancers. We discuss how different genetic alterations can converge to disrupt the epigenome in childhood and adult brain tumors, by causing aberrant DNA methylation and by affecting the amounts and genomic distribution of histone post-translational modifications. We also highlight examples that illustrate how epigenomic alterations have the potential to affect 3D genome architecture in brain tumors. Finally, we will propose the concept of "epigenomic erosion" to explain the transition from stem-like cells to differentiated cells in hierarchically organized brain cancers.
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Affiliation(s)
- Seungil Paik
- Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Francesca Maule
- Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Marco Gallo
- Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.,Arnie Charbonneau Cancer Institute, Alberta Children's Hospital Research Institute, Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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56
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Chu X, Wang J. Microscopic Chromosomal Structural and Dynamical Origin of Cell Differentiation and Reprogramming. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2020; 7:2001572. [PMID: 33101859 PMCID: PMC7578896 DOI: 10.1002/advs.202001572] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Revised: 07/12/2020] [Accepted: 07/23/2020] [Indexed: 06/11/2023]
Abstract
As an essential and fundamental process of life, cell development involves large-scale reorganization of the 3D genome architecture, which forms the basis of gene regulation. Here, a landscape-switching model is developed to explore the microscopic chromosomal structural origin of embryonic stem cell (ESC) differentiation and somatic cell reprogramming. It is shown that chromosome structure exhibits significant compartment-switching in the unit of topologically associating domain. It is found that the chromosome during differentiation undergoes monotonic compaction with spatial repositioning of active and inactive chromosomal loci toward the chromosome surface and interior, respectively. In contrast, an overexpanded chromosome, which exhibits universal localization of loci at the chromosomal surface with erasing the structural characteristics formed in the somatic cells, is observed during reprogramming. An early distinct differentiation pathway from the ESC to the terminally differentiated cell, giving rise to early bifurcation on the Waddington landscape for the ESC differentiation is suggested. The theoretical model herein including the non-equilibrium effects, draws a picture of the highly irreversible cell differentiation and reprogramming processes, in line with the experiments. The predictions provide a physical understanding of cell differentiation and reprogramming from the chromosomal structural and dynamical perspective and can be tested by future experiments.
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Affiliation(s)
- Xiakun Chu
- Department of ChemistryState University of New York at Stony BrookStony BrookNY11794USA
| | - Jin Wang
- Department of ChemistryState University of New York at Stony BrookStony BrookNY11794USA
- Department of Physics and AstronomyState University of New York at Stony BrookStony BrookNY11794USA
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57
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Pennarossa G, Manzoni EFM, Ledda S, deEguileor M, Gandolfi F, Brevini TAL. Use of a PTFE Micro-Bioreactor to Promote 3D Cell Rearrangement and Maintain High Plasticity in Epigenetically Erased Fibroblasts. Stem Cell Rev Rep 2020; 15:82-92. [PMID: 30397853 DOI: 10.1007/s12015-018-9862-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Phenotype definition is driven by epigenetic mechanisms as well as directly influenced by the cell microenvironment and by biophysical signals deriving from the extracellular matrix. The possibility to interact with the epigenetic signature of an adult mature cell, reversing its differentiated state and inducing a short transient high plasticity window, was previously demonstrated. In parallel, in vitro studies have shown that 3D culture systems, mimicking cell native tissue, exert significant effects on cell behavior and functions. Here we report the production of "PTFE micro-bioreactors" for long-term culture of epigenetically derived high plasticity cells. The system promotes 3D cell rearrangement, global DNA demethylation and elevated transcription of pluripotency markers, that is dependent on WW domain containing transcription regulator 1 (TAZ) nuclear accumulation and SMAD family member 2 (SMAD2) co-shuttling. Our findings demonstrate that the use of 3D culture strategies greatly improves the induction and maintenance of a high plasticity state.
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Affiliation(s)
- Georgia Pennarossa
- Laboratory of Biomedical Embryology, Department of Health, Animal Science and Food Safety, Università degli Studi di Milano, 20133, Milan, Italy
| | - Elena F M Manzoni
- Laboratory of Biomedical Embryology, Department of Health, Animal Science and Food Safety, Università degli Studi di Milano, 20133, Milan, Italy
| | - Sergio Ledda
- Department of Veterinary Medicine, University of Sassari, 07100, Sassari, Italy
| | - Magda deEguileor
- Department of Biotechnology and Life Sciences, Università degli Studi dell'Insubria, 21100, Varese, Italy
| | - Fulvio Gandolfi
- Laboratory of Biomedical Embryology, Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, University of Milan, 20133, Milan, Italy.,Unistem, Centre for Stem Cell Research, Universita' degli Studi di Milano, 20133, Milan, Italy
| | - Tiziana A L Brevini
- Laboratory of Biomedical Embryology, Department of Health, Animal Science and Food Safety, Università degli Studi di Milano, 20133, Milan, Italy. .,Unistem, Centre for Stem Cell Research, Universita' degli Studi di Milano, 20133, Milan, Italy.
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58
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Wang J, Liu J, Ye M, Liu F, Wu S, Huang J, Shi G. Ddx56 maintains proliferation of mouse embryonic stem cells via ribosome assembly and interaction with the Oct4/Sox2 complex. Stem Cell Res Ther 2020; 11:314. [PMID: 32703285 PMCID: PMC7376950 DOI: 10.1186/s13287-020-01800-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 06/07/2020] [Accepted: 07/01/2020] [Indexed: 12/17/2022] Open
Abstract
Background Embryonic stem cells (ESCs) are important source of clinical stem cells for therapy, so dissecting the functional gene regulatory network involved in their self-renewal and proliferation is an urgent task. We previously reported that Ddx56 interacts with the core transcriptional factor Oct4 by mass spectrometry analysis in ESCs. However, the exact function of Ddx56 in ESCs remains unclear. Methods We investigated the role of Ddx56 in mouse ESCs (mESCs) through both gain- and loss-of-function strategies. The effect of Ddx56 on mESCs was determined based on morphological changes, involvement in the network of pluripotency markers (Nanog, Oct4, Sox2), and altered lineage marker expression. In addition, the role of Ddx56 in mESCs was evaluated by polysome fractionation, qRT-PCR, and co-immunoprecipitation (co-IP). Finally, RNA sequencing was applied to explore potential network regulation by Ddx56 in mESCs. Result We found that Ddx56 participated in ribosome assembly, as knockout or RNAi knockdown of Ddx56 led to ribosome dysfunction and cell lethality. Surprisingly, exogenous expression of C-terminal domain truncated Ddx56 (Ddx56 ΔC-ter) did not affect ribosome assembly, but decreased mESC proliferation by downregulation of proliferation-related genes and cell cycle changing. In terms of mechanism, Ddx56 interacted with the Oct4 and Sox2 complex by binding to Sox2, whereas Ddx56 ΔC-ter showed weaker interaction with Sox2 and led to retardation of mESC proliferation. Conclusions Ddx56 maintains ESC proliferation by conventional regulation of ribosome assembly and interaction with the Oct4 and Sox2 complex.
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Affiliation(s)
- Jingwen Wang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Jiahui Liu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Miaoman Ye
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Feng Liu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Su Wu
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Junjiu Huang
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China.,Key Laboratory of Reproductive Medicine of Guangdong Province, The First Affiliated Hospital and School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China
| | - Guang Shi
- MOE Key Laboratory of Gene Function and Regulation, State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-sen University, Guangzhou, 510275, China.
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59
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Shanak S, Helms V. DNA methylation and the core pluripotency network. Dev Biol 2020; 464:145-160. [PMID: 32562758 DOI: 10.1016/j.ydbio.2020.06.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 05/01/2020] [Accepted: 06/04/2020] [Indexed: 01/06/2023]
Abstract
From the onset of fertilization, the genome undergoes cell division and differentiation. All of these developmental transitions and differentiation processes include cell-specific signatures and gradual changes of the epigenome. Understanding what keeps stem cells in the pluripotent state and what leads to differentiation are fascinating and biomedically highly important issues. Numerous studies have identified genes, proteins, microRNAs and small molecules that exert essential effects. Notably, there exists a core pluripotency network that consists of several transcription factors and accessory proteins. Three eminent transcription factors, OCT4, SOX2 and NANOG, serve as hubs in this core pluripotency network. They bind to the enhancer regions of their target genes and modulate, among others, the expression levels of genes that are associated with Gene Ontology terms related to differentiation and self-renewal. Also, much has been learned about the epigenetic rewiring processes during these changes of cell fate. For example, DNA methylation dynamics is pivotal during embryonic development. The main goal of this review is to highlight an intricate interplay of (a) DNA methyltransferases controlling the expression levels of core pluripotency factors by modulation of the DNA methylation levels in their enhancer regions, and of (b) the core pluripotency factors controlling the transcriptional regulation of DNA methyltransferases. We discuss these processes both at the global level and in atomistic detail based on information from structural studies and from computer simulations.
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Affiliation(s)
- Siba Shanak
- Faculty of Science, Arab-American University, Jenin, Palestine; Center for Bioinformatics, Saarland University, Saarbruecken, Germany
| | - Volkhard Helms
- Center for Bioinformatics, Saarland University, Saarbruecken, Germany.
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60
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ZSCAN4 facilitates chromatin remodeling and promotes the cancer stem cell phenotype. Oncogene 2020; 39:4970-4982. [PMID: 32507861 PMCID: PMC7314663 DOI: 10.1038/s41388-020-1333-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 04/03/2020] [Accepted: 05/14/2020] [Indexed: 01/01/2023]
Abstract
Cancer stem cells (CSCs) are cells within tumors that maintain the ability to self-renew, drive tumor growth, and contribute to therapeutic resistance and cancer recurrence. In this study, we investigate the role of Zinc finger and SCAN domain containing 4 (ZSCAN4) in human head and neck squamous cell carcinoma (HNSCC). The murine Zscan4 is involved in telomere maintenance and genomic stability of mouse embryonic stem cells. Our data indicate that the human ZSCAN4 is enriched for, marks and is co-expressed with CSC markers in HNSCC. We show that transient ZSCAN4 induction for just 2 days increases CSC frequency both in vitro and in vivo and leads to upregulation of pluripotency and CSC factors. Importantly, we define for the first time the role of ZSCAN4 in altering the epigenetic profile and regulating the chromatin state. Our data show that ZSCAN4 leads to a functional histone 3 hyperacetylation at the promoters of OCT3/4 and NANOG, leading to an upregulation of CSC factors. Consistently, ZSCAN4 depletion leads to downregulation of CSC markers, decreased ability to form tumorspheres and severely affects tumor growth. Our study suggests that ZSCAN4 plays an important role in the maintenance of the CSC phenotype, indicating it is a potential therapeutic target in HNSCC.
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61
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The ubiquitin-conjugating enzyme UBE2K determines neurogenic potential through histone H3 in human embryonic stem cells. Commun Biol 2020; 3:262. [PMID: 32451438 PMCID: PMC7248108 DOI: 10.1038/s42003-020-0984-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2019] [Accepted: 05/01/2020] [Indexed: 01/05/2023] Open
Abstract
Histones modulate gene expression by chromatin compaction, regulating numerous processes such as differentiation. However, the mechanisms underlying histone degradation remain elusive. Human embryonic stem cells (hESCs) have a unique chromatin architecture characterized by low levels of trimethylated histone H3 at lysine 9 (H3K9me3), a heterochromatin-associated modification. Here we assess the link between the intrinsic epigenetic landscape and ubiquitin-proteasome system of hESCs. We find that hESCs exhibit high expression of the ubiquitin-conjugating enzyme UBE2K. Loss of UBE2K upregulates the trimethyltransferase SETDB1, resulting in H3K9 trimethylation and repression of neurogenic genes during differentiation. Besides H3K9 trimethylation, UBE2K binds histone H3 to induce its polyubiquitination and degradation by the proteasome. Notably, ubc-20, the worm orthologue of UBE2K, also regulates histone H3 levels and H3K9 trimethylation in Caenorhabditis elegans germ cells. Thus, our results indicate that UBE2K crosses evolutionary boundaries to promote histone H3 degradation and reduce H3K9me3 repressive marks in immortal cells. Azra Fatima et al. show that ubiquitin-conjugating enzyme UBE2K regulates neurogenic potential through its target histone H3 in human embryonic stem cells. This study suggests that UBE2K promotes histone H3 degradation, reducing the H3K9me3 repressive marks in immortal cells of both worms and humans.
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62
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Stephens AD. Chromatin rigidity provides mechanical and genome protection. Mutat Res 2020; 821:111712. [PMID: 32590202 PMCID: PMC8186544 DOI: 10.1016/j.mrfmmm.2020.111712] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2020] [Revised: 06/05/2020] [Accepted: 06/15/2020] [Indexed: 12/31/2022]
Abstract
The nucleus is the organelle in the cell that contains the genome and its associate proteins which is collectively called chromatin. New work has shown that chromatin and its compaction level, dictated largely through histone modification state, provides rigidity to protect and stabilize the nucleus. Alterations in chromatin, its mechanics, and downstream loss of nuclear shape and stability are hallmarks of human disease. Weakened nuclear mechanics and abnormal morphology have been shown to cause rupturing of the nucleus which results in nuclear dysfunction including DNA damage. Thus, the rigidity provided by chromatin to maintain nuclear mechanical stability also provides its own protection from DNA damage via compartmentalization maintenance.
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Affiliation(s)
- Andrew D Stephens
- Biology Department, University of Massachusetts Amherst, Amherst, MA, 01003, United States.
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63
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Verneri P, Vazquez Echegaray C, Oses C, Stortz M, Guberman A, Levi V. Dynamical reorganization of the pluripotency transcription factors Oct4 and Sox2 during early differentiation of embryonic stem cells. Sci Rep 2020; 10:5195. [PMID: 32251342 PMCID: PMC7089971 DOI: 10.1038/s41598-020-62235-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 03/11/2020] [Indexed: 01/29/2023] Open
Abstract
Pluripotency maintenance requires transcription factors (TFs) that induce genes necessary to preserve the undifferentiated state and repress others involved in differentiation. Recent observations support that the heterogeneous distribution of TFs in the nucleus impacts on gene expression. Thus, it is essential to explore how TFs dynamically organize to fully understand their role in transcription regulation. Here, we examine the distribution of pluripotency TFs Oct4 and Sox2 in the nucleus of embryonic stem (ES) cells and inquire whether their organization changes during early differentiation stages preceding their downregulation. Using ES cells expressing Oct4-YPet or Sox2-YPet, we show that Oct4 and Sox2 partition between nucleoplasm and a few chromatin-dense foci which restructure after inducing differentiation by 2i/LIF withdrawal. Fluorescence correlation spectroscopy showed distinct changes in Oct4 and Sox2 dynamics after differentiation induction. Specifically, we detected an impairment of Oct4-chromatin interactions whereas Sox2 only showed slight variations in its short-lived, and probably more unspecific, interactions with chromatin. Our results reveal that differentiation cues trigger early changes of Oct4 and Sox2 nuclear distributions that also include modifications in TF-chromatin interactions. This dynamical reorganization precedes Oct4 and Sox2 downregulation and may contribute to modulate their function at early differentiation stages.
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Affiliation(s)
- Paula Verneri
- CONICET - Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Instituto de Química Biológica (IQUIBICEN), Buenos Aires, Argentina
| | - Camila Vazquez Echegaray
- CONICET - Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Instituto de Química Biológica (IQUIBICEN), Buenos Aires, Argentina
| | - Camila Oses
- CONICET - Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Instituto de Química Biológica (IQUIBICEN), Buenos Aires, Argentina
| | - Martin Stortz
- CONICET - Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Instituto de Química Biológica (IQUIBICEN), Buenos Aires, Argentina.,Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Buenos Aires, Argentina
| | - Alejandra Guberman
- CONICET - Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Instituto de Química Biológica (IQUIBICEN), Buenos Aires, Argentina. .,Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Fisiología y Biología Molecular y Celular, Buenos Aires, Argentina.
| | - Valeria Levi
- CONICET - Universidad de Buenos Aires, Facultad de Ciencias Exactas y Naturales, Departamento de Química Biológica, Instituto de Química Biológica (IQUIBICEN), Buenos Aires, Argentina.
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64
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Somasundaram L, Levy S, Hussein AM, Ehnes DD, Mathieu J, Ruohola-Baker H. Epigenetic metabolites license stem cell states. Curr Top Dev Biol 2020; 138:209-240. [PMID: 32220298 DOI: 10.1016/bs.ctdb.2020.02.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
It has become clear during recent years that stem cells undergo metabolic remodeling during their activation process. While these metabolic switches take place in pluripotency as well as adult stem cell populations, the rules that govern the switch are not clear. In this review, we summarize some of the transitions in adult and pluripotent cell types and will propose that the key function in this process is the generation of epigenetic metabolites that govern critical epigenetic modifications, and therefore stem cell states.
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Affiliation(s)
- Logeshwaran Somasundaram
- Department of Biochemistry, University of Washington, Seattle, WA, United States; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, United States
| | - Shiri Levy
- Department of Biochemistry, University of Washington, Seattle, WA, United States; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, United States
| | - Abdiasis M Hussein
- Department of Biochemistry, University of Washington, Seattle, WA, United States; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, United States
| | - Devon D Ehnes
- Department of Biochemistry, University of Washington, Seattle, WA, United States; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, United States
| | - Julie Mathieu
- Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, United States; Department of Comparative Medicine, University of Washington, Seattle, WA, United States
| | - Hannele Ruohola-Baker
- Department of Biochemistry, University of Washington, Seattle, WA, United States; Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA, United States.
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65
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Nakagawa T, Wada Y, Katada S, Kishi Y. Epigenetic regulation for acquiring glial identity by neural stem cells during cortical development. Glia 2020; 68:1554-1567. [PMID: 32163194 DOI: 10.1002/glia.23818] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 02/09/2020] [Accepted: 03/02/2020] [Indexed: 12/16/2022]
Abstract
The nervous system consists of several hundred neuronal subtypes and glial cells that show specific gene expression and are generated from common ancestors, neural stem cells (NSCs). As the experimental techniques and molecular tools to analyze epigenetics and chromatin structures are rapidly advancing, the comprehensive events and genome-wide states of DNA methylation, histone modifications, and chromatin accessibility in developing NSCs are gradually being unveiled. Here, we review recent advances in elucidating the role of epigenetic and chromatin regulation in NSCs, especially focusing on the acquisition of glial identity and how epigenetic regulation enables the temporal regulation of NSCs during murine cortical development.
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Affiliation(s)
- Takumi Nakagawa
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yoshikuni Wada
- Laboratory of Molecular Biology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
| | - Sayako Katada
- Department of Stem Cell Biology and Medicine, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan
| | - Yusuke Kishi
- Laboratory of Molecular Biology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, Japan
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66
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The Basal Level of Gene Expression Associated with Chromatin Loosening Shapes Waddington Landscapes and Controls Cell Differentiation. J Mol Biol 2020; 432:2253-2270. [PMID: 32105732 DOI: 10.1016/j.jmb.2020.02.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 02/13/2020] [Accepted: 02/13/2020] [Indexed: 01/01/2023]
Abstract
The baseline level of transcription, which is variable and difficult to quantify, seriously complicates the normalization of comparative transcriptomic data, but its biological importance remains unappreciated. We show that this currently neglected ingredient is essential for controlling gene network multistability and therefore cellular differentiation. Basal expression is correlated to the degree of chromatin loosening measured by DNA accessibility and systematically leads to cellular dedifferentiation as assessed by transcriptomic signatures, irrespective of the molecular and cellular tools used. Modeling gene network motifs formally involved in developmental bifurcations reveals that the epigenetic landscapes of Waddington are restructured by the level of nonspecific expression, such that the attractors of progenitor and differentiated cells can be mutually exclusive. This mechanism is universal and holds beyond the particular nature of the genes involved, provided the multistable circuits are correctly described with autonomous basal expression. These results explain the relationships long established between gene expression noise, chromatin decondensation and cellular dedifferentiation, and highlight how heterochromatin maintenance is essential for preventing pathological cellular reprogramming, age-related diseases, and cancer.
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67
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Effects of Natural Progesterone and Synthetic Progestin on Germ Layer Gene Expression in a Human Embryoid Body Model. Int J Mol Sci 2020; 21:ijms21030769. [PMID: 31991577 PMCID: PMC7036864 DOI: 10.3390/ijms21030769] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2019] [Revised: 01/16/2020] [Accepted: 01/17/2020] [Indexed: 11/17/2022] Open
Abstract
Natural progesterone and synthetic progestin are widely used for the treatment of threatened abortion or in in vitro fertilization (IVF) cycles. This in vitro study aimed to assess whether the treatment with natural progesterone or synthetic progestin influences the germ layer gene expression on the early human embryonic development using human embryonic stem cells (hESCs)-derived embryoid bodies (hEBs) as a surrogate of early stage human embryonic development. Human EBs derived from hESCs were cultured for nine days, and were treated with natural progesterone (P4) or synthetic progestin, medroxyprogesterone acetate (MPA) at 10–7 M for five days. To reverse the effects of treatment, mifepristone (RU486) as progesterone antagonist was added to the hEBs for four days starting one day after the initiation of treatment. Mouse blastocysts (mBLs) were cultured in vitro for 24 h, and P4 or MPA at 10−7 M was treated for an additional 24 h. The treated embryos were further transferred onto in vitro cultured endometrial cells to evaluate chorionic gonadotropin (CG) expression. To analyze the effects of P4 or MPA, the expression of differentiation genes representing the three germ layers was investigated, GATA-binding factor 4 (GATA4), α-fetoprotein (AFP), hepatocyte nuclear factor (HNF)-3β, hepatocyte nuclear factor (HNF)-4α (endoderm), Brachyury, cardiac actin (cACT) (mesoderm), and Nestin (ectoderm), using quantitative reverse transcription PCR (qRT-PCR) and immunostaining. Significantly lower expressions of HNF-3β, HNF-4α, Brachyury, and Nestin were observed in MPA-treated hEBs (all p < 0.05), which was negated by RU486 treatment. This inhibitory effect of MPA was also observed in mouse embryos. Conclusively, the effects of natural progesterone and synthetic progestin may differ in the germ layer gene expression in the hEB model, which suggests that caution is necessary in the use of progestogen.
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68
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Abstract
In eukaryotes, DNA is highly compacted within the nucleus into a structure known as chromatin. Modulation of chromatin structure allows for precise regulation of gene expression, and thereby controls cell fate decisions. Specific chromatin organization is established and preserved by numerous factors to generate desired cellular outcomes. In embryonic stem (ES) cells, chromatin is precisely regulated to preserve their two defining characteristics: self-renewal and pluripotent state. This action is accomplished by a litany of nucleosome remodelers, histone variants, epigenetic marks, and other chromatin regulatory factors. These highly dynamic regulatory factors come together to precisely define a chromatin state that is conducive to ES cell maintenance and development, where dysregulation threatens the survival and fitness of the developing organism.
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Affiliation(s)
- David C Klein
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, United States
| | - Sarah J Hainer
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, United States.
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69
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Wu T, Kamikawa YF, Donohoe ME. Brd4's Bromodomains Mediate Histone H3 Acetylation and Chromatin Remodeling in Pluripotent Cells through P300 and Brg1. Cell Rep 2019; 25:1756-1771. [PMID: 30428346 DOI: 10.1016/j.celrep.2018.10.003] [Citation(s) in RCA: 70] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 11/10/2016] [Accepted: 09/28/2018] [Indexed: 12/22/2022] Open
Abstract
The pluripotent state of embryonic stem cells (ESCs) is defined by its transcriptome and epigenome. The chromatin reader Brd4 determines ESC identity. Although Brd4 regulation in gene transcription has been well described, its contribution to the chromatin landscape is less known. Here, we show that Brd4's bromodomains partner with the histone acetyltransferase P300, increasing its enzymatic activities. Augmenting histone acetylation by Brd4-P300 interaction recruits the chromatin remodeler Brg1 altering chromatin structure. This pathway is important for maintaining the expression and chromatin patterns of pluripotency-associated genes, such as Oct4, Nanog, and the X chromosome regulatory long noncoding RNAs Tsix and Xite. Furthermore, we show that the Brd4-P300 interaction regulates the de novo formation of chromatin marks during ESC differentiation, as exemplified by controlling the master regulators of mesoderm formation. Collectively, we delineate the function of Brd4 in organizing the chromatin structure that contributes to gene transcriptional regulation and cell fate determination.
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Affiliation(s)
- Tao Wu
- Burke Medical Research Institute, White Plains, NY 10605, USA; Department of Neuroscience, Brain Mind Research Institute, Department of Cell & Development, Weill Cornell Medical College, New York, NY 10065, USA
| | - Yasunao F Kamikawa
- Burke Medical Research Institute, White Plains, NY 10605, USA; Department of Neuroscience, Brain Mind Research Institute, Department of Cell & Development, Weill Cornell Medical College, New York, NY 10065, USA
| | - Mary E Donohoe
- Burke Medical Research Institute, White Plains, NY 10605, USA; Department of Neuroscience, Brain Mind Research Institute, Department of Cell & Development, Weill Cornell Medical College, New York, NY 10065, USA.
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70
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Thong T, Forté CA, Hill EM, Colacino JA. Environmental exposures, stem cells, and cancer. Pharmacol Ther 2019; 204:107398. [PMID: 31376432 PMCID: PMC6881547 DOI: 10.1016/j.pharmthera.2019.107398] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Accepted: 07/29/2019] [Indexed: 12/19/2022]
Abstract
An estimated 70-90% of all cancers are linked to exposure to environmental risk factors. In parallel, the number of stem cells in a tissue has been shown to be a strong predictor of risk of developing cancer in that tissue. Tumors themselves are characterized by an acquisition of "stem cell" characteristics, and a growing body of evidence points to tumors themselves being sustained and propagated by a stem cell-like population. Here, we review our understanding of the interplay between environmental exposures, stem cell biology, and cancer. We provide an overview of the role of stem cells in development, tissue homeostasis, and wound repair. We discuss the pathways and mechanisms governing stem cell plasticity and regulation of the stem cell state, and describe experimental methods for assessment of stem cells. We then review the current understanding of how environmental exposures impact stem cell function relevant to carcinogenesis and cancer prevention, with a focus on environmental and occupational exposures to chemical, physical, and biological hazards. We also highlight key areas for future research in this area, including defining whether the biological basis for cancer disparities is related to effects of complex exposure mixtures on stem cell biology.
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Affiliation(s)
- Tasha Thong
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA
| | - Chanese A Forté
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA; Michigan Institute for Computational Discovery and Engineering, University of Michigan, Ann Arbor, MI 48109, USA
| | - Evan M Hill
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA
| | - Justin A Colacino
- Department of Environmental Health Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA; Department of Nutritional Sciences, University of Michigan School of Public Health, Ann Arbor, MI 48109, USA; Center for Computational Medicine and Bioinformatics, University of Michigan, Ann Arbor, MI 48109, USA.
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71
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Wang J, Wu Y, Zhang X, Zhang F, Lü D, Shangguan B, Gao Y, Long M. Flow-enhanced priming of hESCs through H2B acetylation and chromatin decondensation. Stem Cell Res Ther 2019; 10:349. [PMID: 31775893 PMCID: PMC6880446 DOI: 10.1186/s13287-019-1454-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 09/21/2019] [Accepted: 10/15/2019] [Indexed: 01/13/2023] Open
Abstract
BACKGROUND Distinct mechanical stimuli are known to manipulate the behaviors of embryonic stem cells (ESCs). Fundamental rationale of how ESCs respond to mechanical forces and the potential biological effects remain elusive. Here we conducted the mechanobiological study for hESCs upon mechanomics analysis to unravel typical mechanosensitive processes on hESC-specific fluid shear. METHODS hESC line H1 was subjected to systematically varied shear flow, and mechanosensitive proteins were obtained by mass spectrometry (MS) analysis. Then, function enrichment analysis was performed to identify the enriched gene sets. Under a steady shear flow of 1.1 Pa for 24 h, protein expressions were further detected using western blotting (WB), quantitative real-time PCR (qPCR), and immunofluorescence (IF) staining. Meanwhile, the cells were treated with 200 nM trichostatin (TSA) for 1 h as positive control to test chromatin decondensation. Actin, DNA, and RNA were then visualized with TRITC-labeled phalloidin, Hoechst 33342, and SYTO® RNASelect™ green fluorescent cell stain (Life Technologies), respectively. In addition, cell stiffness was determined with atomic force microscopy (AFM) and annexin V-PE was used to determine the apoptosis with a flow cytometer (FCM). RESULTS Typical mechanosensitive proteins were unraveled upon mechanomics analysis under fluid shear related to hESCs in vivo. Functional analyses revealed significant alterations in histone acetylation, nuclear size, and cytoskeleton for hESC under shear flow. Shear flow was able to induce H2B acetylation and nuclear spreading by CFL2/F-actin cytoskeletal reorganization. The resulting chromatin decondensation and a larger nucleus readily accommodate signaling molecules and transcription factors. CONCLUSIONS Shear flow regulated chromatin dynamics in hESCs via cytoskeleton and nucleus alterations and consolidated their primed state.
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Affiliation(s)
- Jiawen Wang
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Yi Wu
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Xiao Zhang
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Fan Zhang
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Dongyuan Lü
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China.,School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China
| | - Bing Shangguan
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Yuxin Gao
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China
| | - Mian Long
- Center for Biomechanics and Bioengineering, Key Laboratory of Microgravity (National Microgravity Laboratory) and Beijing Key Laboratory of Engineered Construction and Mechanobiology, Institute of Mechanics, Chinese Academy of Sciences, Beijing, 100190, China. .,School of Engineering Science, University of Chinese Academy of Sciences, Beijing, China.
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72
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Developmental conservation of microRNA gene localization at the nuclear periphery. PLoS One 2019; 14:e0223759. [PMID: 31682635 PMCID: PMC6827902 DOI: 10.1371/journal.pone.0223759] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 09/27/2019] [Indexed: 12/21/2022] Open
Abstract
microRNAs are of vital importance for the regulation of the adaptive and innate immune responses, modulating gene expression at the post transcriptional level. Although there is cumulative information regarding the steady state mature microRNA levels and their respective targets, little is known about the effect of the three-dimensional chromatin architecture on the transcriptional regulation of microRNA gene loci. Here, we sought to investigate the effect of subnuclear localization on the transcriptional activation of eight murine microRNA loci in the immune system. Our results show that microRNA genes display a preferential monoallelic gene expression profile accompanied with perinuclear localization irrespectively of their transcription status or differentiation state. The expression profile and perinuclear localization are developmentally conserved while microRNA gene loci localization outside constitutive lamin associated domains is cross-species conserved. Our findings provide support for an active nuclear periphery and its role in chromatin organization of the non-coding genome.
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73
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Gandolfi F, Arcuri S, Pennarossa G, Brevini TAL. New tools for cell reprogramming and conversion: Possible applications to livestock. Anim Reprod 2019; 16:475-484. [PMID: 32435291 PMCID: PMC7234139 DOI: 10.21451/1984-3143-ar2019-0043] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Somatic cell nuclear transfer and iPS are both forms of radical cell reprogramming able to transform a fully differentiated cell type into a totipotent or pluripotent cell. Both processes, however, are hampered by low efficiency and, in the case of iPS, the application to livestock species is uncertain. Epigenetic manipulation has recently emerged as an efficient and robust alternative method for cell reprogramming. It is based upon the use of small molecules that are able to modify the levels of DNA methylation with 5-azacitidyne as one of the most widely used. Among a number of advantages, it includes the fact that it can be applied to domestic species including pig, dog and cat. Treated cells undergo a widespread demethylation which is followed by a renewed methylation pattern induced by specific chemical stimuli that lead to the desired phenotype. A detailed study of the mechanisms of epigenetic manipulation revealed that cell plasticity is achieved through the combined action of a reduced DNA methyl transferase activity with an active demethylation driven by the TET protein family. Surprisingly the same combination of molecular processes leads to the transformation of fibroblasts into iPS and regulate the epigenetic changes that take place during early development and, hence, during reprogramming following SCNT. Finally, it has recently emerged that mechanic stimuli in the form of a 3D cell rearrangement can significantly enhance the efficiency of epigenetic reprogramming as well as of maintenance of pluripotency. Interestingly these mechanic stimuli act on the same mechanisms both in epigenetic cell conversion with 5-Aza-CR and in iPS. We suggest that the balanced combination of epigenetic erasing, 3D cell rearrangement and chemical induction can go a long way to obtain ad hoc cell types that can fully exploit the current exiting development brought by gene editing and animal cloning in livestock production.
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Affiliation(s)
- Fulvio Gandolfi
- Department of Agricultural and Environmental Sciences - Production, Landscape, Agroenergy, University of Milan, Italy
| | - Sharon Arcuri
- Department of Health, Animal Science and Food Safety, University of Milan, Italy
| | - Georgia Pennarossa
- Department of Health, Animal Science and Food Safety, University of Milan, Italy
| | - Tiziana A L Brevini
- Department of Health, Animal Science and Food Safety, University of Milan, Italy
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74
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Mallm JP, Windisch P, Biran A, Gal Z, Schumacher S, Glass R, Herold-Mende C, Meshorer E, Barbus M, Rippe K. Glioblastoma initiating cells are sensitive to histone demethylase inhibition due to epigenetic deregulation. Int J Cancer 2019; 146:1281-1292. [PMID: 31456217 DOI: 10.1002/ijc.32649] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/11/2019] [Accepted: 07/30/2019] [Indexed: 12/30/2022]
Abstract
Tumor-initiating cells are a subpopulation of cells that have self-renewal capacity to regenerate a tumor. Here, we identify stem cell-like chromatin features in human glioblastoma initiating cells (GICs) and link them to a loss of the repressive histone H3 lysine 9 trimethylation (H3K9me3) mark. Increasing H3K9me3 levels by histone demethylase inhibition led to cell death in GICs but not in their differentiated counterparts. The induction of apoptosis was accompanied by a loss of the activating H3 lysine 9 acetylation (H3K9ac) modification and accumulation of DNA damage and downregulation of DNA damage response genes. Upon knockdown of histone demethylases, KDM4C and KDM7A both differentiation and DNA damage were induced. Thus, the H3K9me3-H3K9ac equilibrium is crucial for GIC viability and represents a chromatin feature that can be exploited to specifically target this tumor subpopulation.
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Affiliation(s)
- Jan-Philipp Mallm
- Division of Chromatin Networks, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Paul Windisch
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Alva Biran
- Department of Genetics, Institute of Life Sciences, and the Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Zoltan Gal
- Division of Neurosurgical Research, Department of Neurosurgery, University of Heidelberg, Heidelberg, Germany
| | - Sabrina Schumacher
- Division of Chromatin Networks, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Rainer Glass
- Neurosurgical Research, University Hospital, LMU Munich, Munich, Germany
| | - Christel Herold-Mende
- Division of Neurosurgical Research, Department of Neurosurgery, University of Heidelberg, Heidelberg, Germany
| | - Eran Meshorer
- Department of Genetics, Institute of Life Sciences, and the Edmond and Lily Safra Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, Israel
| | - Martje Barbus
- Division of Molecular Genetics, German Cancer Research Center (DKFZ), Heidelberg, Germany
| | - Karsten Rippe
- Division of Chromatin Networks, German Cancer Research Center (DKFZ), Heidelberg, Germany
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75
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Jang J, Han D, Golkaram M, Audouard M, Liu G, Bridges D, Hellander S, Chialastri A, Dey SS, Petzold LR, Kosik KS. Control over single-cell distribution of G1 lengths by WNT governs pluripotency. PLoS Biol 2019; 17:e3000453. [PMID: 31557150 PMCID: PMC6782112 DOI: 10.1371/journal.pbio.3000453] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Revised: 10/08/2019] [Accepted: 09/04/2019] [Indexed: 01/10/2023] Open
Abstract
The link between single-cell variation and population-level fate choices lacks a mechanistic explanation despite extensive observations of gene expression and epigenetic variation among individual cells. Here, we found that single human embryonic stem cells (hESCs) have different and biased differentiation potentials toward either neuroectoderm or mesendoderm depending on their G1 lengths before the onset of differentiation. Single-cell variation in G1 length operates in a dynamic equilibrium that establishes a G1 length probability distribution for a population of hESCs and predicts differentiation outcome toward neuroectoderm or mesendoderm lineages. Although sister stem cells generally share G1 lengths, a variable proportion of cells have asymmetric G1 lengths, which maintains the population dispersion. Environmental Wingless-INT (WNT) levels can control the G1 length distribution, apparently as a means of priming the fate of hESC populations once they undergo differentiation. As a downstream mechanism, global 5-hydroxymethylcytosine levels are regulated by G1 length and thereby link G1 length to differentiation outcomes of hESCs. Overall, our findings suggest that intrapopulation heterogeneity in G1 length underlies the pluripotent differentiation potential of stem cell populations. The link between single-cell variation and population-level fate choices lacks a mechanistic explanation. This study finds that the duration of the G1 cell cycle phase in stem cells varies within the population, giving rise to a probability distribution of G1 length that is responsive to Wnt signalling and that predicts cells’ differentiation potential upon exit from pluripotency.
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Affiliation(s)
- Jiwon Jang
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, California, United States of America
- Department of Life Sciences, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - Dasol Han
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Mahdi Golkaram
- Department of Mechanical Engineering, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Morgane Audouard
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Guojing Liu
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Daniel Bridges
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, California, United States of America
- Department of Physics, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Stefan Hellander
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Alex Chialastri
- Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Siddharth S. Dey
- Department of Chemical Engineering, University of California, Santa Barbara, Santa Barbara, California, United States of America
- Center for Bioengineering, University of California Santa Barbara, Santa Barbara, California, United States of America
| | - Linda R. Petzold
- Department of Mechanical Engineering, University of California, Santa Barbara, Santa Barbara, California, United States of America
- Department of Computer Science, University of California, Santa Barbara, Santa Barbara, California, United States of America
| | - Kenneth S. Kosik
- Department of Molecular, Cellular, and Developmental Biology, Neuroscience Research Institute, University of California, Santa Barbara, Santa Barbara, California, United States of America
- * E-mail:
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Jaroy EG, Acosta-Jimenez L, Hotta R, Goldstein AM, Emblem R, Klungland A, Ougland R. "Too much guts and not enough brains": (epi)genetic mechanisms and future therapies of Hirschsprung disease - a review. Clin Epigenetics 2019; 11:135. [PMID: 31519213 PMCID: PMC6743154 DOI: 10.1186/s13148-019-0718-x] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 07/29/2019] [Indexed: 12/21/2022] Open
Abstract
Hirschsprung disease is a neurocristopathy, characterized by aganglionosis in the distal bowel. It is caused by failure of the enteric nervous system progenitors to migrate, proliferate, and differentiate in the gut. Development of an enteric nervous system is a tightly regulated process. Both the neural crest cells and the surrounding environment are regulated by different genes, signaling pathways, and morphogens. For this process to be successful, the timing of gene expression is crucial. Hence, alterations in expression of genes specific for the enteric nervous system may contribute to the pathogenesis of Hirschsprung’s disease. Several epigenetic mechanisms contribute to regulate gene expression, such as modifications of DNA and RNA, histone modifications, and microRNAs. Here, we review the current knowledge of epigenetic and epitranscriptomic regulation in the development of the enteric nervous system and its potential significance for the pathogenesis of Hirschsprung’s disease. We also discuss possible future therapies and how targeting epigenetic and epitranscriptomic mechanisms may open new avenues for novel treatment.
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Affiliation(s)
- Emilie G Jaroy
- Clinic for Diagnostics and Intervention and Institute of Medical Microbiology, Oslo University Hospital, Rikshospitalet, 0027, Oslo, Norway.,Department of Pediatric Surgery, Oslo University Hospital, Rikshospitalet, 0424, Oslo, Norway.,Faculty of Medicine, Institute of Basic Medical Sciences, University of Oslo, 0317, Oslo, Norway
| | - Lourdes Acosta-Jimenez
- Clinic for Diagnostics and Intervention and Institute of Medical Microbiology, Oslo University Hospital, Rikshospitalet, 0027, Oslo, Norway.,Department of Pediatric Surgery, Oslo University Hospital, Rikshospitalet, 0424, Oslo, Norway.,Faculty of Medicine, Institute of Basic Medical Sciences, University of Oslo, 0317, Oslo, Norway
| | - Ryo Hotta
- Department of Pediatric Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Allan M Goldstein
- Department of Pediatric Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Ragnhild Emblem
- Department of Pediatric Surgery, Oslo University Hospital, Rikshospitalet, 0424, Oslo, Norway.,Faculty of Medicine, Institute of Clinical Medicine, University of Oslo, 0317, Oslo, Norway
| | - Arne Klungland
- Clinic for Diagnostics and Intervention and Institute of Medical Microbiology, Oslo University Hospital, Rikshospitalet, 0027, Oslo, Norway.,Faculty of Medicine, Institute of Basic Medical Sciences, University of Oslo, 0317, Oslo, Norway
| | - Rune Ougland
- Clinic for Diagnostics and Intervention and Institute of Medical Microbiology, Oslo University Hospital, Rikshospitalet, 0027, Oslo, Norway. .,Department of Surgery, Baerum Hospital, Vestre Viken Hospital Trust, 3004, Drammen, Norway.
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77
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A Narrative Role of Vitamin D and Its Receptor: With Current Evidence on the Gastric Tissues. Int J Mol Sci 2019; 20:ijms20153832. [PMID: 31387330 PMCID: PMC6695859 DOI: 10.3390/ijms20153832] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 07/30/2019] [Accepted: 08/01/2019] [Indexed: 02/06/2023] Open
Abstract
Vitamin D is a major steroid hormone that is gaining attention as a therapeutic molecule. Due to the general awareness of its importance for the overall well-being, vitamin D deficiency (VDD) is now recognized as a major health issue. The main reason for VDD is minimal exposure to sunlight. The vitamin D receptor (VDR) is a member of the steroid hormone receptors that induces a cascade of cell signaling to maintain healthy Ca2+ levels that serve to regulate several biological functions. However, the roles of vitamin D and its metabolism in maintaining gastric homeostasis have not yet been completely elucidated. Currently, there is a need to increase the vitamin D status in individuals worldwide as it has been shown to improve musculoskeletal health and reduce the risk of chronic illnesses, including some cancers, autoimmune and infectious diseases, type 2 diabetes mellitus, neurocognitive disorders, and general mortality. The role of vitamin D in gastric homeostasis is crucial and unexplored. This review attempts to elucidate the central role of vitamin D in preserving and maintaining the overall health and homeostasis of the stomach tissue.
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78
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The role of telomere-binding modulators in pluripotent stem cells. Protein Cell 2019; 11:60-70. [PMID: 31350723 PMCID: PMC6949317 DOI: 10.1007/s13238-019-0651-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2019] [Accepted: 05/07/2019] [Indexed: 01/24/2023] Open
Abstract
Pluripotent stem cells (PSCs) such as embryonic stem cells (ESCs), ESCs derived by somatic cell nuclear transfer (ntESCs), and induced pluripotent stem cells (iPSCs) have unlimited capacity for self-renewal and pluripotency and can give rise to all types of somatic cells. In order to maintain their self-renewal and pluripotency, PSCs need to preserve their telomere length and homeostasis. In recent years, increasing studies have shown that telomere reprogramming is essential for stem cell pluripotency maintenance and its induced pluripotency process. Telomere-associated proteins are not only required for telomere maintenance in both stem cells, their extra-telomeric functions have also been found to be critical as well. Here, we will discuss how telomeres and telomere-associated factors participate and regulate the maintenance of stem cell pluripotency.
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79
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Kresoja-Rakic J, Santoro R. Nucleolus and rRNA Gene Chromatin in Early Embryo Development. Trends Genet 2019; 35:868-879. [PMID: 31327501 DOI: 10.1016/j.tig.2019.06.005] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Revised: 06/17/2019] [Accepted: 06/24/2019] [Indexed: 12/16/2022]
Abstract
The nucleolus is the largest substructure in the nucleus and forms around the nucleolar organizer regions (NORs), which comprise hundreds of rRNA genes. Recent evidence highlights further functions of the nucleolus that go beyond ribosome biogenesis. Data indicate that the nucleolus acts as a compartment for the location and regulation of repressive genomic domains and, together with the nuclear lamina, represents the hub for the organization of the inactive heterochromatin. In this review, we discuss recent findings that have revealed how nucleolar structure and rRNA gene chromatin states are regulated during early mammalian development and their contribution to the higher-order spatial organization of the genome.
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Affiliation(s)
- Jelena Kresoja-Rakic
- Department of Molecular Mechanisms of Disease, DMMD, University of Zurich, CH-8057 Zurich, Switzerland
| | - Raffaella Santoro
- Department of Molecular Mechanisms of Disease, DMMD, University of Zurich, CH-8057 Zurich, Switzerland.
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80
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Novo CL, Javierre BM, Cairns J, Segonds-Pichon A, Wingett SW, Freire-Pritchett P, Furlan-Magaril M, Schoenfelder S, Fraser P, Rugg-Gunn PJ. Long-Range Enhancer Interactions Are Prevalent in Mouse Embryonic Stem Cells and Are Reorganized upon Pluripotent State Transition. Cell Rep 2019. [PMID: 29514091 PMCID: PMC5863031 DOI: 10.1016/j.celrep.2018.02.040] [Citation(s) in RCA: 73] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Transcriptional enhancers, including super-enhancers (SEs), form physical interactions with promoters to regulate cell-type-specific gene expression. SEs are characterized by high transcription factor occupancy and large domains of active chromatin, and they are commonly assigned to target promoters using computational predictions. How promoter-SE interactions change upon cell state transitions, and whether transcription factors maintain SE interactions, have not been reported. Here, we used promoter-capture Hi-C to identify promoters that interact with SEs in mouse embryonic stem cells (ESCs). We found that SEs form complex, spatial networks in which individual SEs contact multiple promoters, and a rewiring of promoter-SE interactions occurs between pluripotent states. We also show that long-range promoter-SE interactions are more prevalent in ESCs than in epiblast stem cells (EpiSCs) or Nanog-deficient ESCs. We conclude that SEs form cell-type-specific interaction networks that are partly dependent on core transcription factors, thereby providing insights into the gene regulatory organization of pluripotent cells. Promoter-capture Hi-C identifies 3D interactions in mouse pluripotent cells Super-enhancers (SEs) form complex spatial networks contacting multiple promoters Rewiring of promoter-SE interactions between ESC and EpiSC pluripotent states Long-range SE interactions are a hallmark of mouse ESCs
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Affiliation(s)
- Clara Lopes Novo
- Epigenetics Programme, Babraham Institute, Cambridge CB22 3AT, UK
| | | | - Jonathan Cairns
- Nuclear Dynamics Programme, Babraham Institute, Cambridge CB22 3AT, UK
| | | | - Steven W Wingett
- Bioinformatics Group, Babraham Institute, Cambridge CB22 3AT, UK
| | | | | | | | - Peter Fraser
- Nuclear Dynamics Programme, Babraham Institute, Cambridge CB22 3AT, UK; Department of Biological Science, Florida State University, Tallahassee, FL 32306, USA
| | - Peter J Rugg-Gunn
- Epigenetics Programme, Babraham Institute, Cambridge CB22 3AT, UK; Wellcome Trust - Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, UK.
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81
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Genome Organization in and around the Nucleolus. Cells 2019; 8:cells8060579. [PMID: 31212844 PMCID: PMC6628108 DOI: 10.3390/cells8060579] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 06/09/2019] [Accepted: 06/11/2019] [Indexed: 12/17/2022] Open
Abstract
The nucleolus is the largest substructure in the nucleus, where ribosome biogenesis takes place, and forms around the nucleolar organizer regions (NORs) that comprise ribosomal RNA (rRNA) genes. Each cell contains hundreds of rRNA genes, which are organized in three distinct chromatin and transcriptional states—silent, inactive and active. Increasing evidence indicates that the role of the nucleolus and rRNA genes goes beyond the control of ribosome biogenesis. Recent results highlighted the nucleolus as a compartment for the location and regulation of repressive genomic domains and, together with the nuclear lamina, represents the hub for the organization of the inactive heterochromatin. In this review, we aim to describe the crosstalk between the nucleolus and the rest of the genome and how distinct rRNA gene chromatin states affect nucleolus structure and are implicated in genome stability, genome architecture, and cell fate decision.
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82
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The Role of Ubiquitination in Regulating Embryonic Stem Cell Maintenance and Cancer Development. Int J Mol Sci 2019; 20:ijms20112667. [PMID: 31151253 PMCID: PMC6600158 DOI: 10.3390/ijms20112667] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2019] [Revised: 05/19/2019] [Accepted: 05/28/2019] [Indexed: 12/18/2022] Open
Abstract
Ubiquitination regulates nearly every aspect of cellular events in eukaryotes. It modifies intracellular proteins with 76-amino acid polypeptide ubiquitin (Ub) and destines them for proteolysis or activity alteration. Ubiquitination is generally achieved by a tri-enzyme machinery involving ubiquitin activating enzymes (E1), ubiquitin conjugating enzymes (E2) and ubiquitin ligases (E3). E1 activates Ub and transfers it to the active cysteine site of E2 via a transesterification reaction. E3 coordinates with E2 to mediate isopeptide bond formation between Ub and substrate protein. The E1-E2-E3 cascade can create diverse types of Ub modifications, hence effecting distinct outcomes on the substrate proteins. Dysregulation of ubiquitination results in severe consequences and human diseases. There include cancers, developmental defects and immune disorders. In this review, we provide an overview of the ubiquitination machinery and discuss the recent progresses in the ubiquitination-mediated regulation of embryonic stem cell maintenance and cancer biology.
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83
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Irmak D, Fatima A, Gutiérrez-Garcia R, Rinschen MM, Wagle P, Altmüller J, Arrigoni L, Hummel B, Klein C, Frese CK, Sawarkar R, Rada-Iglesias A, Vilchez D. Mechanism suppressing H3K9 trimethylation in pluripotent stem cells and its demise by polyQ-expanded huntingtin mutations. Hum Mol Genet 2019; 27:4117-4134. [PMID: 30452683 DOI: 10.1093/hmg/ddy304] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Accepted: 08/10/2018] [Indexed: 02/06/2023] Open
Abstract
Pluripotent stem cells are invaluable resources to study development and disease, holding a great promise for regenerative medicine. Here we use human embryonic stem cells (hESCs) and induced pluripotent stem cells (iPSCs) from patients with Huntington's disease (HD-iPSCs) to shed light into the normal function of huntingtin (HTT) and its demise in disease. We find that HTT binds ATF7IP, a regulator of the histone H3 methyltransferase SETDB1. HTT inhibits the interaction of the ATF7IP-SETDB1 complex with other heterochromatin regulators and transcriptional repressors, maintaining low levels of H3K9 trimethylation (H3K9me3) in hESCs. Loss of HTT promotes global increased H3K9me3 levels and enrichment of H3K9me3 marks at distinct genes, including transcriptional regulators of neuronal differentiation. Although these genes are normally expressed at low amounts in hESCs, HTT knockdown (KD) reduces their induction during neural differentiation. Notably, mutant expanded polyglutamine repeats in HTT diminish its interaction with ATF7IP-SETDB1 complex and trigger H3K9me3 in HD-iPSCs. Conversely, KD of ATF7IP in HD-iPSCs reduces H3K9me3 alterations and ameliorates gene expression changes in their neural counterparts. Taken together, our results indicate ATF7IP as a potential target to correct aberrant H3K9me3 levels induced by mutant HTT.
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Affiliation(s)
- Dilber Irmak
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Strasse 26, Cologne, Germany
| | - Azra Fatima
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Strasse 26, Cologne, Germany
| | - Ricardo Gutiérrez-Garcia
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Strasse 26, Cologne, Germany
| | - Markus M Rinschen
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Strasse 26, Cologne, Germany
| | - Prerana Wagle
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Strasse 26, Cologne, Germany
| | - Janine Altmüller
- Center for Molecular Medicine Cologne (CMMC), University of Cologne, Robert-Koch-Strasse 21, Cologne, Germany.,Cologne Center for Genomics (CCG), University of Cologne, Cologne, Germany
| | - Laura Arrigoni
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Barbara Hummel
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Corinna Klein
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Strasse 26, Cologne, Germany
| | - Christian K Frese
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Strasse 26, Cologne, Germany
| | - Ritwick Sawarkar
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Alvaro Rada-Iglesias
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Strasse 26, Cologne, Germany.,Center for Molecular Medicine Cologne (CMMC), University of Cologne, Robert-Koch-Strasse 21, Cologne, Germany
| | - David Vilchez
- Cologne Excellence Cluster for Cellular Stress Responses in Aging-Associated Diseases (CECAD), University of Cologne, Joseph-Stelzmann-Strasse 26, Cologne, Germany
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84
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Nicetto D, Zaret KS. Role of H3K9me3 heterochromatin in cell identity establishment and maintenance. Curr Opin Genet Dev 2019; 55:1-10. [PMID: 31103921 DOI: 10.1016/j.gde.2019.04.013] [Citation(s) in RCA: 148] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Revised: 03/18/2019] [Accepted: 04/15/2019] [Indexed: 01/17/2023]
Abstract
Compacted, transcriptionally repressed chromatin, referred to as heterochromatin, represents a major fraction of the higher eukaryotic genome and exerts pivotal functions of silencing repetitive elements, maintenance of genome stability, and control of gene expression. Among the different histone post-translational modifications (PTMs) associated with heterochromatin, tri-methylation of lysine 9 on histone H3 (H3K9me3) is gaining increased attention. Besides its known role in repressing repetitive elements and non-coding portions of the genome, recent observations indicate H3K9me3 as an important player in silencing lineage-inappropriate genes. The ability of H3K9me3 to influence cell identity challenges the original concept of H3K9me3-marked heterochromatin as mainly a constitutive type of chromatin and provides a further level of understanding of how to modulate cell fate control. Here, we summarize the role of H3K9me3 marked heterochromatin and its dynamics in establishing and maintaining cellular identity.
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Affiliation(s)
- Dario Nicetto
- Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA; Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA; Dept. Cell and Developmental, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA
| | - Kenneth S Zaret
- Institute for Regenerative Medicine, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA; Penn Epigenetics Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA; Dept. Cell and Developmental, Perelman School of Medicine, University of Pennsylvania, Philadelphia, USA.
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85
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Zhou J, Sun J. A Revolution in Reprogramming: Small Molecules. Curr Mol Med 2019; 19:77-90. [DOI: 10.2174/1566524019666190325113945] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Revised: 12/07/2018] [Accepted: 02/18/2019] [Indexed: 02/08/2023]
Abstract
Transplantation of reprogrammed cells from accessible sources and in vivo
reprogramming are potential therapies for regenerative medicine. During the last
decade, genetic approaches, which mostly involved transcription factors and
microRNAs, have been shown to affect cell fates. However, their potential
carcinogenicity and other unexpected effects limit their translation into clinical
applications. Recently, with the power of modern biology-oriented design and synthetic
chemistry, as well as high-throughput screening technology, small molecules have been
shown to enhance reprogramming efficiency, replace genetic factors, and help elucidate
the molecular mechanisms underlying cellular plasticity and degenerative diseases. As a
non-viral and non-integrating approach, small molecules not only show revolutionary
capacities in generating desired exogenous cell types but also have potential as drugs
that can restore tissues through repairing or reprogramming endogenous cells. Here, we
focus on the recent progress made to use small molecules in cell reprogramming along
with some related mechanisms to elucidate these issues.
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Affiliation(s)
- Jin Zhou
- Shanghai Children's Medical Center, Shanghai Jiaotong University, School of Medicine, Shanghai, China
| | - Jie Sun
- Shanghai Children's Medical Center, Shanghai Jiaotong University, School of Medicine, Shanghai, China
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86
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Langer LF, Ward JM, Archer TK. Tumor suppressor SMARCB1 suppresses super-enhancers to govern hESC lineage determination. eLife 2019; 8:45672. [PMID: 31033435 PMCID: PMC6538374 DOI: 10.7554/elife.45672] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 04/29/2019] [Indexed: 12/13/2022] Open
Abstract
The SWI/SNF complex is a critical regulator of pluripotency in human embryonic stem cells (hESCs), and individual subunits have varied and specific roles during development and in diseases. The core subunit SMARCB1 is required for early embryonic survival, and mutations can give rise to atypical teratoid/rhabdoid tumors (AT/RTs) in the pediatric central nervous system. We report that in contrast to other studied systems, SMARCB1 represses bivalent genes in hESCs and antagonizes chromatin accessibility at super-enhancers. Moreover, and consistent with its established role as a CNS tumor suppressor, we find that SMARCB1 is essential for neural induction but dispensable for mesodermal or endodermal differentiation. Mechanistically, we demonstrate that SMARCB1 is essential for hESC super-enhancer silencing in neural differentiation conditions. This genomic assessment of hESC chromatin regulation by SMARCB1 reveals a novel positive regulatory function at super-enhancers and a unique lineage-specific role in regulating hESC differentiation. Our bodies contain trillions of cells that play a wide variety of roles. Despite looking and behaving very differently to one another, all of these ‘mature’ cells somehow descend from a single fertilized egg that contains just one set of genes. This process is partially controlled by how ‘accessible’ genetic material is to the cell machinery that switches genes on or off. For example, in immature brain cells, genes required for memory are accessible, but genes needed to produce bone are not. The developing embryo needs to control gene accessibility carefully to ensure that the right genes become available at the right time, and that crucial genes are not incorrectly ‘hidden’. In humans, the protein SMARCB1 plays an important role in this process: if damaged or deleted, development will be severely disrupted, sometimes causing brain cancer early in life. However, it remains unclear how exactly SMARCB1 regulates the accessibility of its ‘target’ genes. Now, Langer et al. set out to answer this question, and also to determine which parts of the body need SMARCB1 to develop properly. Human stem cells can develop into multiple mature cell types if given the right signals. Langer et al. found reducing levels of SMARCB1 prevented stem cells from maturing into brain cells, but not other kinds of cells. This suggests that SMARCB1 has a specific role in brain development, which is consistent with its devastating effect on brain health when damaged. A detailed analysis of genetic activity and DNA accessibility showed that SMARCB1 was doing this by switching off specific regions of DNA, called stem cell super-enhancers. These regions normally enhance the activity of genes that maintain stem cells in their immature state: when certain super-enhancers are turned off by SMARCB1, this allows stem cells to progress towards a brain cell fate. These results help us understand why damage to SMARCB1 during development causes brain cancer more often than other kinds of cancer. In the future, they could also help explain how certain types of cancer form, which would be the first step towards knowing how to treat them.
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Affiliation(s)
- Lee F Langer
- Laboratory of Epigenetics and Stem Cell Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, United States.,Postdoctoral Research Associate Program, National Institute of General Medical Sciences, National Institutes of Health, Bethesda, United States
| | - James M Ward
- Laboratory of Epigenetics and Stem Cell Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, United States.,Integrative Bioinformatics, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, United States
| | - Trevor K Archer
- Laboratory of Epigenetics and Stem Cell Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, United States
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87
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Turi Z, Lacey M, Mistrik M, Moudry P. Impaired ribosome biogenesis: mechanisms and relevance to cancer and aging. Aging (Albany NY) 2019; 11:2512-2540. [PMID: 31026227 PMCID: PMC6520011 DOI: 10.18632/aging.101922] [Citation(s) in RCA: 110] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 04/04/2019] [Indexed: 02/06/2023]
Abstract
The biosynthesis of ribosomes is a complex process that requires the coordinated action of many factors and a huge energy investment from the cell. Ribosomes are essential for protein production, and thus for cellular survival, growth and proliferation. Ribosome biogenesis is initiated in the nucleolus and includes: the synthesis and processing of ribosomal RNAs, assembly of ribosomal proteins, transport to the cytoplasm and association of ribosomal subunits. The disruption of ribosome biogenesis at various steps, with either increased or decreased expression of different ribosomal components, can promote cell cycle arrest, senescence or apoptosis. Additionally, interference with ribosomal biogenesis is often associated with cancer, aging and age-related degenerative diseases. Here, we review current knowledge on impaired ribosome biogenesis, discuss the main factors involved in stress responses under such circumstances and focus on examples with clinical relevance.
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Affiliation(s)
- Zsofia Turi
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic
| | - Matthew Lacey
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic
| | - Martin Mistrik
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic
| | - Pavel Moudry
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacky University, 779 00 Olomouc, Czech Republic
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88
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Al-Qahtani WS, Abduljabbar M, AlSuhaibani ES, Abel Rahman A, Aljada A. Quantification of the Lamin A/C Transcript Variants in Cancer Cell Lines by Targeted Absolute Quantitative Proteomics and Correlation with mRNA Expression. Int J Mol Sci 2019; 20:ijms20081902. [PMID: 30999625 PMCID: PMC6514937 DOI: 10.3390/ijms20081902] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 04/11/2019] [Accepted: 04/15/2019] [Indexed: 02/06/2023] Open
Abstract
Lamin A/C proteins have key roles in nuclear structural integrity and chromosomal stability. Lamin A/C cumulative protein expression of all variants is reported by semi-quantitative Western blotting. To date, there have not been specific antibodies for the individual Lamin A/C transcript variants. We developed a mass spectrometric approach for the quantification of Lamin A/C transcript variants. A signature peptide for each specific splice variant of Lamin A/C was selected. A LC–MS/MS assay based on the selected signature peptides and their labeled internal standards was established to measure the expression of Lamin A/C transcript variant concentrations. The method validation was carried out according to Food and Drug Administration (FDA) guidelines. The expression levels of the Lamin A/C transcript variants were measured in samples derived from MCF7 and U937 cell lines. RT-qPCR assay was also used to quantitate and compare the mRNA expression of splice variants of Lamin A/C. The established and validated method showed a great linearity, sensitivity, and precision. The different expressed Lamin A/C variants in different cell lines were measured and their levels were in concordance with qRT-PCR results. The developed method is reproducible, reliable, and sensitive for measuring different Lamin A/C transcript variants in different cell lines.
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Affiliation(s)
- Wedad Saeed Al-Qahtani
- Department of Forensic Biology, Faculty of Forensic Sciences, Naif Arab University for Security Sciences, Riyadh 11452, Saudi Arabia.
- Department of Zoology, Faculty of Science, King Saud University, Riyadh 11362, Saudi Arabia.
| | - Mai Abduljabbar
- Newborn Screening & Biochemical Genetics lab, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.
| | - Entissar S AlSuhaibani
- Department of Zoology, Faculty of Science, King Saud University, Riyadh 11362, Saudi Arabia.
| | - Anas Abel Rahman
- Newborn Screening & Biochemical Genetics lab, Department of Genetics, King Faisal Specialist Hospital and Research Center, Riyadh 11211, Saudi Arabia.
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia.
- Department of Chemistry, Memorial University of Newfoundland, St. John's, NL A1B 3X7, Canada.
| | - Ahmad Aljada
- Department of Biochemistry and Molecular Medicine, College of Medicine, Alfaisal University, Riyadh 11533, Saudi Arabia.
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89
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Puri D, Subramanyam D. Stress - (self) eating: Epigenetic regulation of autophagy in response to psychological stress. FEBS J 2019; 286:2447-2460. [PMID: 30927484 DOI: 10.1111/febs.14826] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Revised: 02/19/2019] [Accepted: 03/27/2019] [Indexed: 12/16/2022]
Abstract
Autophagy is a constitutive and cytoprotective catabolic process. Aberrations in autophagy lead to a multitude of degenerative disorders, with neurodegeneration being one of the most widely studied autophagy-related disorders. While the field has largely been focusing on the cytosolic constituents and processes of autophagy, recent studies are increasingly appreciating the role of chromatin modifications and epigenetic regulation in autophagy maintenance. Autophagy has been implicated in the regulation of neurogenesis, and disruption of neurogenesis in response to psychological stress is a proximal risk factor for development of neuropsychiatric disorders such as major depressive disorder (MDD). In this review, we will discuss the regulation of autophagy in normal neurogenesis as well as during chronic psychological stress, focusing on the epigenetic control of autophagy in these contexts, and also highlight the lacunae in our understanding of this process. The systematic study of these regulatory mechanisms will provide a novel therapeutic strategy, based on the use epigenetic regulators of autophagy to enhance neurogenesis and potentially alleviate stress-related behavioral disorders.
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Affiliation(s)
- Deepika Puri
- National Centre for Cell Science, Savitribai Phule Pune University, Pune, India
| | - Deepa Subramanyam
- National Centre for Cell Science, Savitribai Phule Pune University, Pune, India
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90
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Wiese M, Bannister AJ, Basu S, Boucher W, Wohlfahrt K, Christophorou MA, Nielsen ML, Klenerman D, Laue ED, Kouzarides T. Citrullination of HP1γ chromodomain affects association with chromatin. Epigenetics Chromatin 2019; 12:21. [PMID: 30940194 PMCID: PMC6444592 DOI: 10.1186/s13072-019-0265-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 03/19/2019] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Stem cell differentiation involves major chromatin reorganisation, heterochromatin formation and genomic relocalisation of structural proteins, including heterochromatin protein 1 gamma (HP1γ). As the principal reader of the repressive histone marks H3K9me2/3, HP1 plays a key role in numerous processes including heterochromatin formation and maintenance. RESULTS We find that HP1γ is citrullinated in mouse embryonic stem cells (mESCs) and this diminishes when cells differentiate, indicating that it is a dynamically regulated post-translational modification during stem cell differentiation. Peptidylarginine deiminase 4, a known regulator of pluripotency, citrullinates HP1γ in vitro. This requires R38 and R39 within the HP1γ chromodomain, and the catalytic activity is enhanced by trimethylated H3K9 (H3K9me3) peptides. Mutation of R38 and R39, designed to mimic citrullination, affects HP1γ binding to H3K9me3-containing peptides. Using live-cell single-particle tracking, we demonstrate that R38 and R39 are important for HP1γ binding to chromatin in vivo. Furthermore, their mutation reduces the residence time of HP1γ on chromatin in differentiating mESCs. CONCLUSION Citrullination is a novel post-translational modification of the structural heterochromatin protein HP1γ in mESCs that is dynamically regulated during mESC differentiation. The citrullinated residues lie within the HP1γ chromodomain and are important for H3K9me3 binding in vitro and chromatin association in vivo.
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Affiliation(s)
- Meike Wiese
- The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN UK
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP UK
- Max Planck Institute for Immunobiology and Epigenetics, Stuebeweg 51, 79108 Freiburg, Germany
| | - Andrew J. Bannister
- The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN UK
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP UK
| | - Srinjan Basu
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA UK
- Wellcome-MRC Cambridge Stem Cell Institute, Cambridge, CB2 1QR UK
| | - Wayne Boucher
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA UK
| | - Kai Wohlfahrt
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA UK
| | - Maria A. Christophorou
- Institute of Genetics and Molecular Medicine, Western General Hospital, University of Edinburgh, Crewe Road South, Edinburgh, EH4 2XU UK
| | - Michael L. Nielsen
- Department of Proteomics, The Novo Nordisk Foundation Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3b, 2200 Copenhagen, Denmark
| | - David Klenerman
- Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW UK
| | - Ernest D. Laue
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA UK
| | - Tony Kouzarides
- The Gurdon Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN UK
- Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QP UK
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91
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The Role of RNA Polymerase II Contiguity and Long-Range Interactions in the Regulation of Gene Expression in Human Pluripotent Stem Cells. Stem Cells Int 2019; 2019:1375807. [PMID: 30863449 PMCID: PMC6378007 DOI: 10.1155/2019/1375807] [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: 08/06/2018] [Revised: 12/05/2018] [Accepted: 12/24/2018] [Indexed: 12/02/2022] Open
Abstract
The eukaryotic nucleus is a highly complex structure that carries out multiple functions primarily needed for gene expression, and among them, transcription seems to be the most fundamental. Diverse approaches have demonstrated that transcription takes place at discrete sites known as transcription factories, wherein RNA polymerase II (RNAP II) is attached to the factory and immobilized while transcribing DNA. It has been proposed that transcription factories promote chromatin loop formation, creating long-range interactions in which relatively distant genes can be transcribed simultaneously. In this study, we examined long-range interactions between the POU5F1 gene and genes previously identified as being POU5F1 enhancer-interacting, namely, CDYL, TLE2, RARG, and MSX1 (all involved in transcriptional regulation), in human pluripotent stem cells (hPSCs) and their early differentiated counterparts. As a control gene, RUNX1 was used, which is expressed during hematopoietic differentiation and not associated with pluripotency. To reveal how these long-range interactions between POU5F1 and the selected genes change with the onset of differentiation and upon RNAP II inhibition, we performed three-dimensional fluorescence in situ hybridization (3D-FISH) followed by computational simulation analysis. Our analysis showed that the numbers of long-range interactions between specific genes decrease during differentiation, suggesting that the transcription of monitored genes is associated with pluripotency. In addition, we showed that upon inhibition of RNAP II, long-range associations do not disintegrate and remain constant. We also analyzed the distance distributions of these genes in the context of their positions in the nucleus and revealed that they tend to have similar patterns resembling normal distribution. Furthermore, we compared data created in vitro and in silico to assess the biological relevance of our results.
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92
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Shuzui E, Kim MH, Kino-oka M. Anomalous cell migration triggers a switch to deviation from the undifferentiated state in colonies of human induced pluripotent stems on feeder layers. J Biosci Bioeng 2019; 127:246-255. [DOI: 10.1016/j.jbiosc.2018.07.020] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 07/02/2018] [Accepted: 07/24/2018] [Indexed: 01/07/2023]
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93
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Henry MP, Hawkins JR, Boyle J, Bridger JM. The Genomic Health of Human Pluripotent Stem Cells: Genomic Instability and the Consequences on Nuclear Organization. Front Genet 2019; 9:623. [PMID: 30719030 PMCID: PMC6348275 DOI: 10.3389/fgene.2018.00623] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/23/2018] [Indexed: 12/11/2022] Open
Abstract
Human pluripotent stem cells (hPSCs) are increasingly used for cell-based regenerative therapies worldwide, with embryonic and induced pluripotent stem cells as potential treatments for debilitating and chronic conditions, such as age-related macular degeneration, Parkinson's disease, spinal cord injuries, and type 1 diabetes. However, with the level of genomic anomalies stem cells generate in culture, their safety may be in question. Specifically, hPSCs frequently acquire chromosomal abnormalities, often with gains or losses of whole chromosomes. This review discusses how important it is to efficiently and sensitively detect hPSC aneuploidies, to understand how these aneuploidies arise, consider the consequences for the cell, and indeed the individual to whom aneuploid cells may be administered.
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Affiliation(s)
- Marianne P Henry
- Advanced Therapies Division, National Institute for Biological Standards and Control, Potters Bar, United Kingdom.,Laboratory of Nuclear and Genomic Health, Division of Biosciences, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, London, United Kingdom
| | - J Ross Hawkins
- Advanced Therapies Division, National Institute for Biological Standards and Control, Potters Bar, United Kingdom
| | - Jennifer Boyle
- Advanced Therapies Division, National Institute for Biological Standards and Control, Potters Bar, United Kingdom
| | - Joanna M Bridger
- Laboratory of Nuclear and Genomic Health, Division of Biosciences, Department of Life Sciences, College of Health and Life Sciences, Brunel University London, London, United Kingdom
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94
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Khateb M, Azriel A, Levi BZ. The Third Intron of IRF8 Is a Cell-Type-Specific Chromatin Priming Element during Mouse Embryonal Stem Cell Differentiation. J Mol Biol 2019; 431:210-222. [PMID: 30502383 DOI: 10.1016/j.jmb.2018.11.022] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Revised: 11/07/2018] [Accepted: 11/20/2018] [Indexed: 01/09/2023]
Abstract
Interferon regulatory factor 8 (IRF8) is a nuclear transcription factor that plays a key role in the hierarchical differentiation of hematopoietic stem cells toward monocyte/dendritic cell lineages. Therefore, its expression is mainly limited to bone marrow-derived cells. The molecular mechanisms governing this cell-type-restricted expression have been described. However, the molecular mechanisms that are responsible for its silencing in non-hematopoietic cells are elusive. Recently, we demonstrated a role for IRF8 third intron in restricting its expression in non-hematopoietic cells. Furthermore, we showed that this intron alone is sufficient to promote repressed chromatin a cell-type-specific manner. Here we demonstrate the effect of the IRF8 third intron on chromatin conformation during murine embryonal stem cell differentiation. Using genome editing, we provide data showing that the third intron plays a key role in priming the chromatin state of the IRF8 locus during cell differentiation. It mediates dual regulatory effects in a cell-type-specific mode. It acts as a repressor element governing chromatin state of the IRF8 locus during embryonal stem cell differentiation to cardiomyocytes that are expression-restrictive cells. Conversely, it functions as an activator element that is essential for open chromatin structure during the differentiation of these cells to dendritic cells that are expression-permissive cells. Together, these results point to the role of IRF8 third intron as a cell-type-specific chromatin priming element during embryonal stem cell differentiation. These data add another layer to our understanding of the molecular mechanisms governing misexpression of a cell-type-specific gene such as IRF8.
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Affiliation(s)
- Mamduh Khateb
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Aviva Azriel
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel
| | - Ben-Zion Levi
- Department of Biotechnology and Food Engineering, Technion-Israel Institute of Technology, Haifa 32000, Israel.
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95
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Nicetto D, Donahue G, Jain T, Peng T, Sidoli S, Sheng L, Montavon T, Becker JS, Grindheim JM, Blahnik K, Garcia BA, Tan K, Bonasio R, Jenuwein T, Zaret KS. H3K9me3-heterochromatin loss at protein-coding genes enables developmental lineage specification. Science 2019; 363:294-297. [PMID: 30606806 PMCID: PMC6664818 DOI: 10.1126/science.aau0583] [Citation(s) in RCA: 126] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Revised: 10/23/2018] [Accepted: 12/20/2018] [Indexed: 12/22/2022]
Abstract
Gene silencing by chromatin compaction is integral to establishing and maintaining cell fates. Trimethylated histone 3 lysine 9 (H3K9me3)-marked heterochromatin is reduced in embryonic stem cells compared to differentiated cells. However, the establishment and dynamics of closed regions of chromatin at protein-coding genes, in embryologic development, remain elusive. We developed an antibody-independent method to isolate and map compacted heterochromatin from low-cell number samples. We discovered high levels of compacted heterochromatin, H3K9me3-decorated, at protein-coding genes in early, uncommitted cells at the germ-layer stage, undergoing profound rearrangements and reduction upon differentiation, concomitant with cell type-specific gene expression. Perturbation of the three H3K9me3-related methyltransferases revealed a pivotal role for H3K9me3 heterochromatin during lineage commitment at the onset of organogenesis and for lineage fidelity maintenance.
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Affiliation(s)
- Dario Nicetto
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Greg Donahue
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Tanya Jain
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Tao Peng
- Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Division of Oncology and Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, PA, USA
| | - Simone Sidoli
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA, USA
| | - Lihong Sheng
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Thomas Montavon
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Justin S Becker
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Jessica M Grindheim
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Kimberly Blahnik
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, USA
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Benjamin A Garcia
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA, USA
| | - Kai Tan
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Biomedical and Health Informatics, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Division of Oncology and Center for Childhood Cancer Research, Children's Hospital of Philadelphia, Philadelphia, PA, USA
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Roberto Bonasio
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
| | - Thomas Jenuwein
- Max Planck Institute of Immunobiology and Epigenetics, Freiburg, Germany
| | - Kenneth S Zaret
- Institute for Regenerative Medicine, University of Pennsylvania, Philadelphia, PA, USA.
- Penn Epigenetics Institute, University of Pennsylvania, Philadelphia, PA, USA
- Department of Cell and Developmental Biology, University of Pennsylvania, Philadelphia, PA, USA
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96
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Zaidan NZ, Walker KJ, Brown JE, Schaffer LV, Scalf M, Shortreed MR, Iyer G, Smith LM, Sridharan R. Compartmentalization of HP1 Proteins in Pluripotency Acquisition and Maintenance. Stem Cell Reports 2019; 10:627-641. [PMID: 29358085 PMCID: PMC5830946 DOI: 10.1016/j.stemcr.2017.12.016] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Revised: 12/19/2017] [Accepted: 12/20/2017] [Indexed: 12/31/2022] Open
Abstract
The heterochromatin protein 1 (HP1) family is involved in various functions with maintenance of chromatin structure. During murine somatic cell reprogramming, we find that early depletion of HP1γ reduces the generation of induced pluripotent stem cells, while late depletion enhances the process, with a concomitant change from a centromeric to nucleoplasmic localization and elongation-associated histone H3.3 enrichment. Depletion of heterochromatin anchoring protein SENP7 increased reprogramming efficiency to a similar extent as HP1γ, indicating the importance of HP1γ release from chromatin for pluripotency acquisition. HP1γ interacted with OCT4 and DPPA4 in HP1α and HP1β knockouts and in H3K9 methylation depleted H3K9M embryonic stem cell (ESC) lines. HP1α and HP1γ complexes in ESCs differed in association with histones, the histone chaperone CAF1 complex, and specific components of chromatin-modifying complexes such as DPY30, implying distinct functional contributions. Taken together, our results reveal the complex contribution of the HP1 proteins to pluripotency. Release of HP1γ from anchoring by Senp7 increases reprogramming efficiency HP1γ switches enrichment from histone H1 to histone H3.3 in pluripotent cells HP1γ interacts with OCT4 and DPPA4 independent of HP1α, HP1β, and H3K9 methylation Proteomic characterization of HP1 protein family in pluripotent cells
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Affiliation(s)
- Nur Zafirah Zaidan
- Epigenetics Theme, Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA; Genetics Training Program, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Kolin J Walker
- Epigenetics Theme, Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Jaime E Brown
- Epigenetics Theme, Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Leah V Schaffer
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Mark Scalf
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Michael R Shortreed
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Gopal Iyer
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Lloyd M Smith
- Department of Chemistry, University of Wisconsin-Madison, Madison, WI 53715, USA
| | - Rupa Sridharan
- Epigenetics Theme, Wisconsin Institute for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA; Department of Cell and Regenerative Biology, University of Wisconsin-Madison, Madison, WI 53715, USA.
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97
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Schlesinger S, Meshorer E. Open Chromatin, Epigenetic Plasticity, and Nuclear Organization in Pluripotency. Dev Cell 2019; 48:135-150. [DOI: 10.1016/j.devcel.2019.01.003] [Citation(s) in RCA: 61] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 10/30/2018] [Accepted: 12/31/2018] [Indexed: 12/27/2022]
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98
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Shivashankar GV. Mechanical regulation of genome architecture and cell-fate decisions. Curr Opin Cell Biol 2018; 56:115-121. [PMID: 30554028 DOI: 10.1016/j.ceb.2018.12.001] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Revised: 11/29/2018] [Accepted: 12/01/2018] [Indexed: 02/07/2023]
Abstract
Landmark experiments in vitro showed that somatic cells can be reprogrammed to stem-cells by the constitutive expression of particular transcription factors. However, in vivo cells naturally exhibit de-differentiation and trans-differentiation programs, thereby suggesting that the signals from the local mechanical microenvironment may be sufficient to induce stem-cell state transitions. In this review, we discuss recent evidence for the biophysical regulation of genome architecture and nuclear programs. We start by discussing the coupling between cellular architecture, genome organization and gene expression. We then review the role of biophysical factors in regulating genome architecture and cell-state transitions. Finally, we discuss the molecular basis of cell-state transitions during nuclear reprogramming. Collectively, we highlight the importance of the mechanical regulation of genome organization on cell-fate decisions.
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Affiliation(s)
- G V Shivashankar
- Mechanobiology Institute, National University of Singapore, Singapore & FIRC Institute of Molecular Oncology (IFOM), Milan, Italy.
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99
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Alhaji SY, Ngai SC, Abdullah S. Silencing of transgene expression in mammalian cells by DNA methylation and histone modifications in gene therapy perspective. Biotechnol Genet Eng Rev 2018; 35:1-25. [PMID: 30514178 DOI: 10.1080/02648725.2018.1551594] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
DNA methylation and histone modifications are vital in maintaining genomic stability and modulating cellular functions in mammalian cells. These two epigenetic modifications are the most common gene regulatory systems known to spatially control gene expression. Transgene silencing by these two mechanisms is a major challenge to achieving effective gene therapy for many genetic conditions. The implications of transgene silencing caused by epigenetic modifications have been extensively studied and reported in numerous gene delivery studies. This review highlights instances of transgene silencing by DNA methylation and histone modification with specific focus on the role of these two epigenetic effects on the repression of transgene expression in mammalian cells from integrative and non-integrative based gene delivery systems in the context of gene therapy. It also discusses the prospects of achieving an effective and sustained transgene expression for future gene therapy applications.
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Affiliation(s)
- Suleiman Yusuf Alhaji
- a Medical Genetics Laboratory, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences , Universiti Putra Malaysia, UPM , Serdang , Malaysia.,b Department of Human Anatomy , College of Medical Sciences, Abubakar Tafawa Balewa University Bauchi, ATBU , Bauchi , Nigeria
| | - Siew Ching Ngai
- c School of Biosciences, Faculty of Science , University of Nottingham Malaysia , Semenyih , Malaysia
| | - Syahril Abdullah
- a Medical Genetics Laboratory, Department of Biomedical Sciences, Faculty of Medicine and Health Sciences , Universiti Putra Malaysia, UPM , Serdang , Malaysia.,d UPM-MAKNA Cancer Research Laboratory, Institute of Bioscience , Universiti Putra Malaysia, UPM , Serdang , Malaysia
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100
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Yadav T, Quivy JP, Almouzni G. Chromatin plasticity: A versatile landscape that underlies cell fate and identity. Science 2018; 361:1332-1336. [PMID: 30262494 DOI: 10.1126/science.aat8950] [Citation(s) in RCA: 118] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
During development and throughout life, a variety of specialized cells must be generated to ensure the proper function of each tissue and organ. Chromatin plays a key role in determining cellular state, whether totipotent, pluripotent, multipotent, or differentiated. We highlight chromatin dynamics involved in the generation of pluripotent stem cells as well as their influence on cell fate decision and reprogramming. We focus on the capacity of histone variants, chaperones, modifications, and heterochromatin factors to influence cell identity and its plasticity. Recent technological advances have provided tools to elucidate the underlying chromatin dynamics for a better understanding of normal development and pathological conditions, with avenues for potential therapeutic application.
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Affiliation(s)
- Tejas Yadav
- Institut Curie, 75248 Paris Cedex 05, France
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