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Garate X, Gómez-García PA, Merino MF, Angles MC, Zhu C, Castells-García A, Ed-Daoui I, Martin L, Ochiai H, Neguembor MV, Cosma MP. The relationship between nanoscale genome organization and gene expression in mouse embryonic stem cells during pluripotency transition. Nucleic Acids Res 2024:gkae476. [PMID: 38850157 DOI: 10.1093/nar/gkae476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2023] [Revised: 05/16/2024] [Accepted: 06/05/2024] [Indexed: 06/10/2024] Open
Abstract
During early development, gene expression is tightly regulated. However, how genome organization controls gene expression during the transition from naïve embryonic stem cells to epiblast stem cells is still poorly understood. Using single-molecule microscopy approaches to reach nanoscale resolution, we show that genome remodeling affects gene transcription during pluripotency transition. Specifically, after exit from the naïve pluripotency state, chromatin becomes less compacted, and the OCT4 transcription factor has lower mobility and is more bound to its cognate sites. In epiblast cells, the active transcription hallmark, H3K9ac, decreases within the Oct4 locus, correlating with reduced accessibility of OCT4 and, in turn, with reduced expression of Oct4 nascent RNAs. Despite the high variability in the distances between active pluripotency genes, distances between Nodal and Oct4 decrease during epiblast specification. In particular, highly expressed Oct4 alleles are closer to nuclear speckles during all stages of the pluripotency transition, while only a distinct group of highly expressed Nodal alleles are in close proximity to Oct4 when associated with a nuclear speckle in epiblast cells. Overall, our results provide new insights into the role of the spatiotemporal genome remodeling during mouse pluripotency transition and its correlation with the expression of key pluripotency genes.
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Affiliation(s)
- Ximena Garate
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Pablo Aurelio Gómez-García
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Manuel Fernández Merino
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Marta Cadevall Angles
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Chenggan Zhu
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Alvaro Castells-García
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 106 Zhongshan Er Road, Yuexiu district, 510080 Guangzhou, China
| | - Ilyas Ed-Daoui
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 106 Zhongshan Er Road, Yuexiu district, 510080 Guangzhou, China
| | - Laura Martin
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Hiroshi Ochiai
- Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, 739-0046, Japan
| | - Maria Victoria Neguembor
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
| | - Maria Pia Cosma
- Centre for Genomic Regulation (CRG), The Barcelona Institute of Science and Technology, Dr. Aiguader 88, Barcelona 08003, Spain
- Medical Research Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, 106 Zhongshan Er Road, Yuexiu district, 510080 Guangzhou, China
- ICREA, Pg. Lluis Companys 23, Barcelona 08010, Spain
- Universitat Pompeu Fabra (UPF), Barcelona, Spain
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2
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Zheng SS, Wu JF, Wu WX, Hu JW, Zhang D, Huang C, Zhang BH. CBX1 is involved in hepatocellular carcinoma progression and resistance to sorafenib and lenvatinib via IGF-1R/AKT/SNAIL signaling pathway. Hepatol Int 2024:10.1007/s12072-024-10696-0. [PMID: 38769286 DOI: 10.1007/s12072-024-10696-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Accepted: 04/29/2024] [Indexed: 05/22/2024]
Abstract
BACKGROUND Chromobox Homolog 1 (CBX1) plays a crucial role in the pathogenesis of numerous diseases, including the evolution and advancement of diverse cancers. The role of CBX1 in pan-cancer and its mechanism in hepatocellular carcinoma (HCC), however, remains to be further investigated. METHODS Bioinformatics approaches were harnessed to scrutinize CBX1's expression profile, its association with tumor staging, and its potential impact on patient outcomes across various cancers. Single-cell RNA sequencing data facilitated the investigation of CBX1 expression patterns at the individual cell level. The CBX1 expression levels in HCC and adjacent non-tumor tissues were quantified through Real-Time Polymerase Chain Reaction (RT-PCR), Western Blotting (WB), and Immunohistochemical analyses. A tissue microarray was employed to explore the relationship between CBX1 levels, patient prognosis, and clinicopathological characteristics in HCC. Various in vitro assays-including CCK-8, colony formation, Transwell invasion, and scratch tests-were conducted to assess the proliferative and motility properties of HCC cells upon modulation of CBX1 expression. Moreover, the functional impact of CBX1 on HCC was further discerned through xenograft studies in nude mice. RESULTS CBX1 was found to be upregulated in most cancer forms, with heightened expression correlating with adverse patient prognoses. Within the context of HCC, elevated levels of CBX1 were consistently indicative of poorer clinical outcomes. Suppression of CBX1 through knockdown methodologies markedly diminished HCC cell proliferation, invasive capabilities, migratory activity, Epithelial-mesenchymal transition (EMT) processes, and resistance to Tyrosine kinase inhibitors (TKIs). Contrastingly, CBX1 augmentation facilitated the opposite effects. Subsequent investigative efforts revealed CBX1 to be a promoter of EMT and a contributor to increased TKI resistance within HCC cells, mediated via the IGF-1R/AKT/SNAIL signaling axis. The oncogenic activities of CBX1 proved to be attenuable either by AKT pathway inhibition or by targeted silencing of IGF-1R. CONCLUSIONS The broad overexpression of CBX1 in pan-cancer and specifically in HCC positions it as a putative oncogenic entity. It is implicated in forwarding HCC progression and exacerbating TKI resistance through its interaction with the IGF-1R/AKT/SNAIL signaling cascade.
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Affiliation(s)
- Su-Su Zheng
- Department of Hepatic Oncology, Xiamen Clinical Research Center for Cancer Therapy, Zhongshan Hospital, Fudan University (Xiamen Branch), Xiamen, 361015, China
| | - Jing-Fang Wu
- Department of Hepatic Oncology, Liver Cancer Institute, Key Laboratory for Carcinogenesis and Cancer Invasion (Ministry of Education), Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Wei-Xun Wu
- Department of Liver Surgery, Zhongshan Hospital, Fudan University (Xiamen Branch), Xiamen, 361015, China
| | - Jin-Wu Hu
- Department of Liver Cancer, Shanghai Geriatrics Medical Center, 2560 Chunshen Road, Shanghai, 201104, China
| | - Dai Zhang
- Department of Hepatic Oncology, Liver Cancer Institute, Key Laboratory for Carcinogenesis and Cancer Invasion (Ministry of Education), Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China
| | - Cheng Huang
- Department of Liver Surgery, Liver Cancer Institute, Key Laboratory of Carcinogenesis and Cancer Invasion (Ministry of Education), Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
| | - Bo-Heng Zhang
- Department of Hepatic Oncology, Xiamen Clinical Research Center for Cancer Therapy, Zhongshan Hospital, Fudan University (Xiamen Branch), Xiamen, 361015, China.
- Department of Hepatic Oncology, Liver Cancer Institute, Key Laboratory for Carcinogenesis and Cancer Invasion (Ministry of Education), Zhongshan Hospital, Fudan University, 180 Fenglin Road, Shanghai, 200032, China.
- Center for Evidence-Based Medicine, Shanghai Medical School, Fudan University, Shanghai, 200032, China.
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3
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Parra AS, Johnston CA. Phase Separation as a Driver of Stem Cell Organization and Function during Development. J Dev Biol 2023; 11:45. [PMID: 38132713 PMCID: PMC10743522 DOI: 10.3390/jdb11040045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2023] [Revised: 12/04/2023] [Accepted: 12/08/2023] [Indexed: 12/23/2023] Open
Abstract
A properly organized subcellular composition is essential to cell function. The canonical organizing principle within eukaryotic cells involves membrane-bound organelles; yet, such structures do not fully explain cellular complexity. Furthermore, discrete non-membrane-bound structures have been known for over a century. Liquid-liquid phase separation (LLPS) has emerged as a ubiquitous mode of cellular organization without the need for formal lipid membranes, with an ever-expanding and diverse list of cellular functions that appear to be regulated by this process. In comparison to traditional organelles, LLPS can occur across wider spatial and temporal scales and involves more distinct protein and RNA complexes. In this review, we discuss the impacts of LLPS on the organization of stem cells and their function during development. Specifically, the roles of LLPS in developmental signaling pathways, chromatin organization, and gene expression will be detailed, as well as its impacts on essential processes of asymmetric cell division. We will also discuss how the dynamic and regulated nature of LLPS may afford stem cells an adaptable mode of organization throughout the developmental time to control cell fate. Finally, we will discuss how aberrant LLPS in these processes may contribute to developmental defects and disease.
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Canat A, Veillet A, Batrin R, Dubourg C, Lhoumaud P, Arnau-Romero P, Greenberg MVC, Bonhomme F, Arimondo PB, Illingworth R, Fabre E, Therizols P. DAXX safeguards heterochromatin formation in embryonic stem cells. J Cell Sci 2023; 136:jcs261092. [PMID: 37655670 DOI: 10.1242/jcs.261092] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Accepted: 08/25/2023] [Indexed: 09/02/2023] Open
Abstract
Genomes comprise a large fraction of repetitive sequences folded into constitutive heterochromatin, which protect genome integrity and cell identity. De novo formation of heterochromatin during preimplantation development is an essential step for preserving the ground-state of pluripotency and the self-renewal capacity of embryonic stem cells (ESCs). However, the molecular mechanisms responsible for the remodeling of constitutive heterochromatin are largely unknown. Here, we identify that DAXX, an H3.3 chaperone essential for the maintenance of mouse ESCs in the ground state, accumulates in pericentromeric regions independently of DNA methylation. DAXX recruits PML and SETDB1 to promote the formation of heterochromatin, forming foci that are hallmarks of ground-state ESCs. In the absence of DAXX or PML, the three-dimensional (3D) architecture and physical properties of pericentric and peripheral heterochromatin are disrupted, resulting in de-repression of major satellite DNA, transposable elements and genes associated with the nuclear lamina. Using epigenome editing tools, we observe that H3.3, and specifically H3.3K9 modification, directly contribute to maintaining pericentromeric chromatin conformation. Altogether, our data reveal that DAXX is crucial for the maintenance and 3D organization of the heterochromatin compartment and protects ESC viability.
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Affiliation(s)
- Antoine Canat
- Université de Paris, Laboratoire Génomes, Biologie Cellulaire et Thérapeutiques, CNRS UMR7212, INSERM U944, Institut de Recherche St Louis, F-75010 Paris, France
| | - Adeline Veillet
- Université de Paris, Laboratoire Génomes, Biologie Cellulaire et Thérapeutiques, CNRS UMR7212, INSERM U944, Institut de Recherche St Louis, F-75010 Paris, France
| | - Renaud Batrin
- Université de Paris, Laboratoire Génomes, Biologie Cellulaire et Thérapeutiques, CNRS UMR7212, INSERM U944, Institut de Recherche St Louis, F-75010 Paris, France
| | - Clara Dubourg
- Université de Paris, Laboratoire Génomes, Biologie Cellulaire et Thérapeutiques, CNRS UMR7212, INSERM U944, Institut de Recherche St Louis, F-75010 Paris, France
| | | | - Pol Arnau-Romero
- Université Paris Cité, CNRS, Institut Jacques Monod, F-75013 Paris, France
| | | | - Frédéric Bonhomme
- Institut Pasteur, Université Paris Cité, CNRS, Epigenetic Chemical Biology, UMR 3523, F-75724 Paris, France
| | - Paola B Arimondo
- Institut Pasteur, Université Paris Cité, CNRS, Epigenetic Chemical Biology, UMR 3523, F-75724 Paris, France
| | - Robert Illingworth
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, The University of Edinburgh, Edinburgh BioQuarter, 5 Little France Drive, Edinburgh EH16 4UU, UK
| | - Emmanuelle Fabre
- Université de Paris, Laboratoire Génomes, Biologie Cellulaire et Thérapeutiques, CNRS UMR7212, INSERM U944, Institut de Recherche St Louis, F-75010 Paris, France
| | - Pierre Therizols
- Université de Paris, Laboratoire Génomes, Biologie Cellulaire et Thérapeutiques, CNRS UMR7212, INSERM U944, Institut de Recherche St Louis, F-75010 Paris, France
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5
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Joron K, Viegas JO, Haas-Neill L, Bier S, Drori P, Dvir S, Lim PSL, Rauscher S, Meshorer E, Lerner E. Fluorescent protein lifetimes report densities and phases of nuclear condensates during embryonic stem-cell differentiation. Nat Commun 2023; 14:4885. [PMID: 37573411 PMCID: PMC10423231 DOI: 10.1038/s41467-023-40647-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Accepted: 08/03/2023] [Indexed: 08/14/2023] Open
Abstract
Fluorescent proteins (FP) are frequently used for studying proteins inside cells. In advanced fluorescence microscopy, FPs can report on additional intracellular variables. One variable is the local density near FPs, which can be useful in studying densities within cellular bio-condensates. Here, we show that a reduction in fluorescence lifetimes of common monomeric FPs reports increased levels of local densities. We demonstrate the use of this fluorescence-based variable to report the distribution of local densities within heterochromatin protein 1α (HP1α) in mouse embryonic stem cells (ESCs), before and after early differentiation. We find that local densities within HP1α condensates in pluripotent ESCs are heterogeneous and cannot be explained by a single liquid phase. Early differentiation, however, induces a change towards a more homogeneous distribution of local densities, which can be explained as a liquid-like phase. In conclusion, we provide a fluorescence-based method to report increased local densities and apply it to distinguish between homogeneous and heterogeneous local densities within bio-condensates.
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Affiliation(s)
- Khalil Joron
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Juliane Oliveira Viegas
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Liam Haas-Neill
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
- Department of Physics, University of Toronto, Toronto, ON, M5S 1A7, Canada
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Sariel Bier
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Paz Drori
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Shani Dvir
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel
| | - Patrick Siang Lin Lim
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel
| | - Sarah Rauscher
- Department of Chemical and Physical Sciences, University of Toronto Mississauga, Mississauga, ON, L5L 1C6, Canada
- Department of Physics, University of Toronto, Toronto, ON, M5S 1A7, Canada
- Department of Chemistry, University of Toronto, 80 St. George Street, Toronto, ON, M5S 3H6, Canada
| | - Eran Meshorer
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Edmond J. Safra Campus, Givat Ram, Jerusalem, 91904, Israel.
- Edmond and Lily Center for Brain Sciences (ELSC), The Hebrew University of Jerusalem, Jerusalem, 91904, Israel.
| | - Eitan Lerner
- Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, Faculty of Mathematics & Science, The Edmond J. Safra Campus, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel.
- The Center for Nanoscience and Nanotechnology, The Hebrew University of Jerusalem, Jerusalem, 9190401, Israel.
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6
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Li X, Li L, Xiong X, Kuang Q, Peng M, Zhu K, Luo P. Identification of the Prognostic Biomarkers CBX6 and CBX7 in Bladder Cancer. Diagnostics (Basel) 2023; 13:diagnostics13081393. [PMID: 37189494 DOI: 10.3390/diagnostics13081393] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 03/22/2023] [Accepted: 04/07/2023] [Indexed: 05/17/2023] Open
Abstract
BACKGROUND Chromobox (CBX) proteins are essential components of polycomb group proteins and perform essential functions in bladder cancer (BLCA). However, research on CBX proteins is still limited, and the function of CBXs in BLCA has not been well illustrated. METHODS AND RESULTS We analyzed the expression of CBX family members in BLCA patients from The Cancer Genome Atlas database. By Cox regression analysis and survival analysis, CBX6 and CBX7 were identified as potential prognostic factors. Subsequently, we identified genes associated with CBX6/7 and performed enrichment analysis, and they were enriched in urothelial carcinoma and transitional carcinoma. Mutation rates of TP53 and TTN correlate with expression of CBX6/7. In addition, differential analysis indicated that the roles played by CBX6 and CBX7 may be related to immune checkpoints. The CIBERSORT algorithm was used to screen out immune cells that play a role in the prognosis of bladder cancer patients. Multiplex immunohistochemistry staining confirmed a negative correlation between CBX6 and M1 macrophages, as well as a consistent alteration in CBX6 and regulatory T cells (Tregs), a positive correlation between CBX7 and resting mast cells, and a negative correlation between CBX7 and M0 macrophages. CONCLUSIONS CBX6 and CBX7 expression levels may assist in predicting the prognosis of BLCA patients. CBX6 may contribute to a poor prognosis in patients by inhibiting M1 polarization and promoting Treg recruitment in the tumor microenvironment, while CBX7 may contribute to a better prognosis in patients by increasing resting mast cell numbers and decreasing macrophage M0 content.
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Affiliation(s)
- Xinxin Li
- Department of Urology, Wuhan Third Hospital and Tongren Hospital of Wuhan University, Wuhan 430060, China
| | - Lili Li
- Central Laboratory, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Xi Xiong
- Department of Urology, Wuhan Third Hospital, School of Medicine, Wuhan University of Science and Technology, Wuhan 430060, China
| | - Qihui Kuang
- Department of Urology, Wuhan Third Hospital and Tongren Hospital of Wuhan University, Wuhan 430060, China
| | - Min Peng
- Department of Oncology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Kai Zhu
- Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan 430060, China
| | - Pengcheng Luo
- Department of Urology, Wuhan Third Hospital and Tongren Hospital of Wuhan University, Wuhan 430060, China
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7
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Spracklin G, Abdennur N, Imakaev M, Chowdhury N, Pradhan S, Mirny LA, Dekker J. Diverse silent chromatin states modulate genome compartmentalization and loop extrusion barriers. Nat Struct Mol Biol 2023; 30:38-51. [PMID: 36550219 PMCID: PMC9851908 DOI: 10.1038/s41594-022-00892-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Accepted: 11/01/2022] [Indexed: 12/24/2022]
Abstract
The relationships between chromosomal compartmentalization, chromatin state and function are poorly understood. Here by profiling long-range contact frequencies in HCT116 colon cancer cells, we distinguish three silent chromatin states, comprising two types of heterochromatin and a state enriched for H3K9me2 and H2A.Z that exhibits neutral three-dimensional interaction preferences and which, to our knowledge, has not previously been characterized. We find that heterochromatin marked by H3K9me3, HP1α and HP1β correlates with strong compartmentalization. We demonstrate that disruption of DNA methyltransferase activity greatly remodels genome compartmentalization whereby domains lose H3K9me3-HP1α/β binding and acquire the neutrally interacting state while retaining late replication timing. Furthermore, we show that H3K9me3-HP1α/β heterochromatin is permissive to loop extrusion by cohesin but refractory to CTCF binding. Together, our work reveals a dynamic structural and organizational diversity of the silent portion of the genome and establishes connections between the regulation of chromatin state and chromosome organization, including an interplay between DNA methylation, compartmentalization and loop extrusion.
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Affiliation(s)
- George Spracklin
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA.
- Department of Systems Biology, University of Massachusetts Medical School, Worcester, MA, USA.
| | - Nezar Abdennur
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Maxim Imakaev
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Neil Chowdhury
- Program for Research in Mathematics, Engineering and Science for High School Students (PRIMES), MIT, Cambridge, MA, USA
| | - Sriharsa Pradhan
- Genome Biology Division, New England Biolabs, Inc., Ipswich, MA, USA
| | - Leonid A Mirny
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
- Department of Physics, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA
| | - Job Dekker
- Department of Systems Biology, University of Massachusetts Medical School, Worcester, MA, USA.
- Howard Hughes Medical Institute, Chevy Chase, USA.
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8
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Ballmer D, Tardat M, Ortiz R, Graff-Meyer A, Ozonov E, Genoud C, Peters A, Fanourgakis G. HP1 proteins regulate nucleolar structure and function by secluding pericentromeric constitutive heterochromatin. Nucleic Acids Res 2022; 51:117-143. [PMID: 36533441 PMCID: PMC9841413 DOI: 10.1093/nar/gkac1159] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 10/29/2022] [Accepted: 12/13/2022] [Indexed: 12/23/2022] Open
Abstract
Nucleoli are nuclear compartments regulating ribosome biogenesis and cell growth. In embryonic stem cells (ESCs), nucleoli containing transcriptionally active ribosomal genes are spatially separated from pericentromeric satellite repeat sequences packaged in largely repressed constitutive heterochromatin (PCH). To date, mechanisms underlying such nuclear partitioning and the physiological relevance thereof are unknown. Here we show that repressive chromatin at PCH ensures structural integrity and function of nucleoli during cell cycle progression. Loss of heterochromatin proteins HP1α and HP1β causes deformation of PCH, with reduced H3K9 trimethylation (H3K9me3) and HP1γ levels, absence of H4K20me3 and upregulated major satellites expression. Spatially, derepressed PCH aberrantly associates with nucleoli accumulating severe morphological defects during S/G2 cell cycle progression. Hp1α/β deficiency reduces cell proliferation, ribosomal RNA biosynthesis and mobility of Nucleophosmin, a major nucleolar component. Nucleolar integrity and function require HP1α/β proteins to be recruited to H3K9me3-marked PCH and their ability to dimerize. Correspondingly, ESCs deficient for both Suv39h1/2 H3K9 HMTs display similar nucleolar defects. In contrast, Suv4-20h1/2 mutant ESCs lacking H4K20me3 at PCH do not. Suv39h1/2 and Hp1α/β deficiency-induced nucleolar defects are reminiscent of those defining human ribosomopathy disorders. Our results reveal a novel role for SUV39H/HP1-marked repressive constitutive heterochromatin in regulating integrity, function and physiology of nucleoli.
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Affiliation(s)
- Daniel Ballmer
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland,Faculty of Sciences, University of Basel, 4056 Basel, Switzerland
| | - Mathieu Tardat
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Raphael Ortiz
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Alexandra Graff-Meyer
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Evgeniy A Ozonov
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Christel Genoud
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | | | - Grigorios Fanourgakis
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
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9
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Herman N, Kadener S, Shifman S. The chromatin factor ROW cooperates with BEAF-32 in regulating long-range inducible genes. EMBO Rep 2022; 23:e54720. [PMID: 36245419 PMCID: PMC9724677 DOI: 10.15252/embr.202254720] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 09/19/2022] [Accepted: 09/29/2022] [Indexed: 11/07/2022] Open
Abstract
Insulator proteins located at the boundaries of topological associated domains (TAD) are involved in higher-order chromatin organization and transcription regulation. However, it is still not clear how long-range contacts contribute to transcriptional regulation. Here, we show that relative-of-WOC (ROW) is essential for the long-range transcription regulation mediated by the boundary element-associated factor of 32kD (BEAF-32). We find that ROW physically interacts with heterochromatin proteins (HP1b and HP1c) and the insulator protein (BEAF-32). These proteins interact at TAD boundaries where ROW, through its AT-hook motifs, binds AT-rich sequences flanked by BEAF-32-binding sites and motifs. Knockdown of row downregulates genes that are long-range targets of BEAF-32 and bound indirectly by ROW (without binding motif). Analyses of high-throughput chromosome conformation capture (Hi-C) data reveal long-range interactions between promoters of housekeeping genes bound directly by ROW and promoters of developmental genes bound indirectly by ROW. Thus, our results show cooperation between BEAF-32 and the ROW complex, including HP1 proteins, to regulate the transcription of developmental and inducible genes through long-range interactions.
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Affiliation(s)
- Neta Herman
- Department of Genetics, The Institute of Life SciencesThe Hebrew University of JerusalemJerusalemIsrael
| | | | - Sagiv Shifman
- Department of Genetics, The Institute of Life SciencesThe Hebrew University of JerusalemJerusalemIsrael
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10
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Establishment of H3K9-methylated heterochromatin and its functions in tissue differentiation and maintenance. Nat Rev Mol Cell Biol 2022; 23:623-640. [PMID: 35562425 PMCID: PMC9099300 DOI: 10.1038/s41580-022-00483-w] [Citation(s) in RCA: 115] [Impact Index Per Article: 57.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/30/2022] [Indexed: 12/14/2022]
Abstract
Heterochromatin is characterized by dimethylated or trimethylated histone H3 Lys9 (H3K9me2 or H3K9me3, respectively) and is found at transposable elements, satellite repeats and genes, where it ensures their transcriptional silencing. The histone methyltransferases (HMTs) that methylate H3K9 — in mammals Suppressor of variegation 3–9 homologue 1 (SUV39H1), SUV39H2, SET domain bifurcated 1 (SETDB1), SETDB2, G9A and G9A-like protein (GLP) — and the ‘readers’ of H3K9me2 or H3K9me3 are highly conserved and show considerable redundancy. Despite their redundancy, genetic ablation or mistargeting of an individual H3K9 methyltransferase can correlate with impaired cell differentiation, loss of tissue identity, premature aging and/or cancer. In this Review, we discuss recent advances in understanding the roles of the known H3K9-specific HMTs in ensuring transcriptional homeostasis during tissue differentiation in mammals. We examine the effects of H3K9-methylation-dependent gene repression in haematopoiesis, muscle differentiation and neurogenesis in mammals, and compare them with mechanistic insights obtained from the study of model organisms, notably Caenorhabditis elegans and Drosophila melanogaster. In all these organisms, H3K9-specific HMTs have both unique and redundant roles that ensure the maintenance of tissue integrity by restricting the binding of transcription factors to lineage-specific promoters and enhancer elements. Histone H3 Lys9 (H3K9)-methylated heterochromatin ensures transcriptional silencing of repetitive elements and genes, and its deregulation leads to impaired cell and tissue identity, premature aging and cancer. Recent studies in mammals clarified the roles H3K9-specific histone methyltransferases in ensuring transcriptional homeostasis during tissue differentiation.
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11
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DNA sequence-dependent formation of heterochromatin nanodomains. Nat Commun 2022; 13:1861. [PMID: 35387992 PMCID: PMC8986797 DOI: 10.1038/s41467-022-29360-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Accepted: 03/03/2022] [Indexed: 01/08/2023] Open
Abstract
The mammalian epigenome contains thousands of heterochromatin nanodomains (HNDs) marked by di- and trimethylation of histone H3 at lysine 9 (H3K9me2/3), which have a typical size of 3–10 nucleosomes. However, what governs HND location and extension is only partly understood. Here, we address this issue by introducing the chromatin hierarchical lattice framework (ChromHL) that predicts chromatin state patterns with single-nucleotide resolution. ChromHL is applied to analyse four HND types in mouse embryonic stem cells that are defined by histone methylases SUV39H1/2 or GLP, transcription factor ADNP or chromatin remodeller ATRX. We find that HND patterns can be computed from PAX3/9, ADNP and LINE1 sequence motifs as nucleation sites and boundaries that are determined by DNA sequence (e.g. CTCF binding sites), cooperative interactions between nucleosomes as well as nucleosome-HP1 interactions. Thus, ChromHL rationalizes how patterns of H3K9me2/3 are established and changed via the activity of protein factors in processes like cell differentiation. The ability to predict epigenetic regulation is an important challenge in biology. Here the authors describe heterochromatin nanodomains (HNDs) and compare four different types of H3K9me2/3-marked HNDs in mouse embryonic stem cells. They further develop a computational framework to predict genome-wide HND maps from DNA sequence and protein concentrations, at single-nucleotide resolution.
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12
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Han D, Wu G, Chen R, Drexler HCA, MacCarthy CM, Kim KP, Adachi K, Gerovska D, Mavrommatis L, Bedzhov I, Araúzo-Bravo MJ, Schöler HR. A balanced Oct4 interactome is crucial for maintaining pluripotency. SCIENCE ADVANCES 2022; 8:eabe4375. [PMID: 35171666 PMCID: PMC8849292 DOI: 10.1126/sciadv.abe4375] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Accepted: 12/21/2021] [Indexed: 06/14/2023]
Abstract
Oct4 collaborates primarily with other transcriptional factors or coregulators to maintain pluripotency. However, how Oct4 exerts its function is still unclear. Here, we show that the Oct4 linker interface mediates competing yet balanced Oct4 protein interactions that are crucial for maintaining pluripotency. Oct4 linker mutant embryonic stem cells (ESCs) show decreased expression of self-renewal genes and increased expression of differentiation genes, resulting in impaired ESC self-renewal and early embryonic development. The linker mutation interrupts the balanced Oct4 interactome. In mutant ESCs, the interaction between Oct4 and Klf5 is decreased. In contrast, interactions between Oct4 and Cbx1, Ctr9, and Cdc73 are increased, disrupting the epigenetic state of ESCs. Control of the expression level of Klf5, Cbx1, or Cdc73 rebalances the Oct4 interactome and rescues the pluripotency of linker mutant ESCs, indicating that such factors interact with Oct4 competitively. Thus, we provide previously unidentified molecular insights into how Oct4 maintains pluripotency.
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Affiliation(s)
- Dong Han
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Guangming Wu
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
- Guangzhou Regenerative Medicine and Health Guangdong Laboratory, 6 Luoxuan Avenue, Haizhu District, 510320 Guangzhou, P. R. China
| | - Rui Chen
- Embryonic Self-Organization Research Group, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Hannes C. A. Drexler
- Bioanalytical Mass Spectrometry, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Caitlin M. MacCarthy
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Kee-Pyo Kim
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
- Department of Medical Life Sciences, College of Medicine, The Catholic University of Korea, 222 Banpo-daero Seocho-gu, Seoul 06591, Republic of Korea
| | - Kenjiro Adachi
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Daniela Gerovska
- Group of Computational Biology and Systems Biomedicine, Biodonostia Health Research Institute, San Sebastian 20014, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao 48011, Spain
| | - Lampros Mavrommatis
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Ivan Bedzhov
- Embryonic Self-Organization Research Group, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
| | - Marcos J. Araúzo-Bravo
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
- Group of Computational Biology and Systems Biomedicine, Biodonostia Health Research Institute, San Sebastian 20014, Spain
- IKERBASQUE, Basque Foundation for Science, Bilbao 48011, Spain
| | - Hans R. Schöler
- Department of Cell and Developmental Biology, Max Planck Institute for Molecular Biomedicine, Röntgenstrasse 20, 48149 Münster, Germany
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Abstract
In eukaryotic cells, protein and RNA factors involved in genome activities like transcription, RNA processing, DNA replication, and repair accumulate in self-organizing membraneless chromatin subcompartments. These structures contribute to efficiently conduct chromatin-mediated reactions and to establish specific cellular programs. However, the underlying mechanisms for their formation are only partly understood. Recent studies invoke liquid-liquid phase separation (LLPS) of proteins and RNAs in the establishment of chromatin activity patterns. At the same time, the folding of chromatin in the nucleus can drive genome partitioning into spatially distinct domains. Here, the interplay between chromatin organization, chromatin binding, and LLPS is discussed by comparing and contrasting three prototypical chromatin subcompartments: the nucleolus, clusters of active RNA polymerase II, and pericentric heterochromatin domains. It is discussed how the different ways of chromatin compartmentalization are linked to transcription regulation, the targeting of soluble factors to certain parts of the genome, and to disease-causing genetic aberrations.
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Affiliation(s)
- Karsten Rippe
- Division of Chromatin Networks, German Cancer Research Center (DKFZ) and Bioquant, 69120 Heidelberg, Germany
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14
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Wootton J, Soutoglou E. Chromatin and Nuclear Dynamics in the Maintenance of Replication Fork Integrity. Front Genet 2022; 12:773426. [PMID: 34970302 PMCID: PMC8712883 DOI: 10.3389/fgene.2021.773426] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Accepted: 11/24/2021] [Indexed: 11/13/2022] Open
Abstract
Replication of the eukaryotic genome is a highly regulated process and stringent control is required to maintain genome integrity. In this review, we will discuss the many aspects of the chromatin and nuclear environment that play key roles in the regulation of both unperturbed and stressed replication. Firstly, the higher order organisation of the genome into A and B compartments, topologically associated domains (TADs) and sub-nuclear compartments has major implications in the control of replication timing. In addition, the local chromatin environment defined by non-canonical histone variants, histone post-translational modifications (PTMs) and enrichment of factors such as heterochromatin protein 1 (HP1) plays multiple roles in normal S phase progression and during the repair of replicative damage. Lastly, we will cover how the spatial organisation of stalled replication forks facilitates the resolution of replication stress.
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Affiliation(s)
- Jack Wootton
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, United Kingdom
| | - Evi Soutoglou
- Genome Damage and Stability Centre, School of Life Sciences, University of Sussex, Brighton, United Kingdom
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15
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Qin W, Ugur E, Mulholland CB, Bultmann S, Solovei I, Modic M, Smets M, Wierer M, Forné I, Imhof A, Cardoso MC, Leonhardt H. Phosphorylation of the HP1β hinge region sequesters KAP1 in heterochromatin and promotes the exit from naïve pluripotency. Nucleic Acids Res 2021; 49:7406-7423. [PMID: 34214177 PMCID: PMC8287961 DOI: 10.1093/nar/gkab548] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 05/31/2021] [Accepted: 06/11/2021] [Indexed: 12/26/2022] Open
Abstract
Heterochromatin binding protein HP1β plays an important role in chromatin organization and cell differentiation, however the underlying mechanisms remain unclear. Here, we generated HP1β−/− embryonic stem cells and observed reduced heterochromatin clustering and impaired differentiation. We found that during stem cell differentiation, HP1β is phosphorylated at serine 89 by CK2, which creates a binding site for the pluripotency regulator KAP1. This phosphorylation dependent sequestration of KAP1 in heterochromatin compartments causes a downregulation of pluripotency factors and triggers pluripotency exit. Accordingly, HP1β−/− and phospho-mutant cells exhibited impaired differentiation, while ubiquitination-deficient KAP1−/− cells had the opposite phenotype with enhanced differentiation. These results suggest that KAP1 regulates pluripotency via its ubiquitination activity. We propose that the formation of subnuclear membraneless heterochromatin compartments may serve as a dynamic reservoir to trap or release cellular factors. The sequestration of essential regulators defines a novel and active role of heterochromatin in gene regulation and represents a dynamic mode of remote control to regulate cellular processes like cell fate decisions.
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Affiliation(s)
- Weihua Qin
- Faculty of Biology, Ludwig-Maximilians-Universität München, Butenandtstraße 1, D-81377 Munich, Germany
| | - Enes Ugur
- Faculty of Biology, Ludwig-Maximilians-Universität München, Butenandtstraße 1, D-81377 Munich, Germany.,Department of Proteomics and Signal Transduction, Max Planck Institute for Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Christopher B Mulholland
- Faculty of Biology, Ludwig-Maximilians-Universität München, Butenandtstraße 1, D-81377 Munich, Germany
| | - Sebastian Bultmann
- Faculty of Biology, Ludwig-Maximilians-Universität München, Butenandtstraße 1, D-81377 Munich, Germany
| | - Irina Solovei
- Faculty of Biology, Ludwig-Maximilians-Universität München, Butenandtstraße 1, D-81377 Munich, Germany
| | - Miha Modic
- The Francis Crick Institute and UCL Queen Square Institute of Neurology, London NW1 1AT, United Kingdom
| | - Martha Smets
- Faculty of Biology, Ludwig-Maximilians-Universität München, Butenandtstraße 1, D-81377 Munich, Germany
| | - Michael Wierer
- Department of Proteomics and Signal Transduction, Max Planck Institute for Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Ignasi Forné
- Biomedical Center Munich, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Str. 9, 82152 Planegg-Martinsried, Germany
| | - Axel Imhof
- Biomedical Center Munich, Faculty of Medicine, Ludwig-Maximilians-Universität München, Großhaderner Str. 9, 82152 Planegg-Martinsried, Germany
| | - M Cristina Cardoso
- Cell Biology and Epigenetics, Department of Biology, Technical University of Darmstadt, 64287 Darmstadt, Germany
| | - Heinrich Leonhardt
- Faculty of Biology, Ludwig-Maximilians-Universität München, Butenandtstraße 1, D-81377 Munich, Germany
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16
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Olivieri D, Paramanathan S, Bardet AF, Hess D, Smallwood SA, Elling U, Betschinger J. The BTB-domain transcription factor ZBTB2 recruits chromatin remodelers and a histone chaperone during the exit from pluripotency. J Biol Chem 2021; 297:100947. [PMID: 34270961 PMCID: PMC8350017 DOI: 10.1016/j.jbc.2021.100947] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 06/21/2021] [Accepted: 07/08/2021] [Indexed: 12/12/2022] Open
Abstract
Transcription factors (TFs) harboring broad-complex, tramtrack, and bric-a-brac (BTB) domains play important roles in development and disease. These BTB domains are thought to recruit transcriptional modulators to target DNA regions. However, a systematic molecular understanding of the mechanism of action of this TF family is lacking. Here, we identify the zinc finger BTB-TF Zbtb2 from a genetic screen for regulators of exit from pluripotency and demonstrate that its absence perturbs embryonic stem cell differentiation and the gene expression dynamics underlying peri-implantation development. We show that ZBTB2 binds the chromatin remodeler Ep400 to mediate downstream transcription. Independently, the BTB domain directly interacts with nucleosome remodeling and deacetylase and histone chaperone histone regulator A. Nucleosome remodeling and deacetylase recruitment is a common feature of BTB TFs, and based on phylogenetic analysis, we propose that this is a conserved evolutionary property. Binding to UBN2, in contrast, is specific to ZBTB2 and requires a C-terminal extension of the BTB domain. Taken together, this study identifies a BTB-domain TF that recruits chromatin modifiers and a histone chaperone during a developmental cell state transition and defines unique and shared molecular functions of the BTB-domain TF family.
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Affiliation(s)
- Daniel Olivieri
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
| | | | - Anaïs F Bardet
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland; CNRS, University of Strasbourg, UMR7242 Biotechnology and Cell Signaling, Illkirch, France
| | - Daniel Hess
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | | | - Ulrich Elling
- Institute of Molecular Biotechnology of the Austrian Academy of Science (IMBA), Vienna BioCenter (VBC), Vienna, Austria
| | - Joerg Betschinger
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland.
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17
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Tien CL, Mohammadparast S, Chang C. Heterochromatin protein 1 beta regulates neural and neural crest development by repressing pluripotency-associated gene pou5f3.2/oct25 in Xenopus. Dev Dyn 2021; 250:1113-1124. [PMID: 33595886 DOI: 10.1002/dvdy.319] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 02/09/2021] [Accepted: 02/09/2021] [Indexed: 01/28/2023] Open
Abstract
BACKGROUND Heterochromatin protein 1 (HP1) is associated with and plays a role in compact chromatin conformation, but the function of HP1 in vertebrate embryogenesis is not understood completely. RESULTS Here, we explore the activity of HP1 in early neural development in the frog Xenopus laevis. We show that the three isoforms of HP1, HP1α, β, and γ, are expressed in similar patterns in the neural and neural crest derivatives in early embryos. Despite this, knockdown of HP1β and HP1γ, but not HP1α, in presumptive neural tissues leads to head defects. Late pan-neural markers and neural crest specifier genes are reduced, but early neural and neural plate border genes are less affected in the morphant embryos. Further investigation reveals that neuronal differentiation is impaired and a pluripotency-associated gene, pou5f3.2/oct25, is expanded in HP1β morphants. Ectopic expression of pou5f3.2/oct25 mimics the effect of HP1β knockdown on marker expression, whereas simultaneous knockdown of HP1β and pou5f3.2/oct25 partially rescues expression of these genes. CONCLUSION Taken together, the data suggest that HP1β regulates transition from precursor to more differentiated cell types during neural and neural crest development in Xenopus, and it does so at least partially via repression of the pluripotency-associated transcription regulator pou5f3.2/oct25.
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Affiliation(s)
- Chih-Liang Tien
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Saeid Mohammadparast
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Chenbei Chang
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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18
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Chromatin Regulation in Development: Current Understanding and Approaches. Stem Cells Int 2021; 2021:8817581. [PMID: 33603792 PMCID: PMC7872760 DOI: 10.1155/2021/8817581] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 12/29/2020] [Accepted: 01/21/2021] [Indexed: 11/24/2022] Open
Abstract
The regulation of mammalian stem cell fate during differentiation is complex and can be delineated across many levels. At the chromatin level, the replacement of histone variants by chromatin-modifying proteins, enrichment of specific active and repressive histone modifications, long-range gene interactions, and topological changes all play crucial roles in the determination of cell fate. These processes control regulatory elements of critical transcriptional factors, thereby establishing the networks unique to different cell fates and initiate waves of distinctive transcription events. Due to the technical challenges posed by previous methods, it was difficult to decipher the mechanism of cell fate determination at early embryogenesis through chromatin regulation. Recently, single-cell approaches have revolutionised the field of developmental biology, allowing unprecedented insights into chromatin structure and interactions in early lineage segregation events during differentiation. Here, we review the recent technological advancements and how they have furthered our understanding of chromatin regulation during early differentiation events.
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19
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van Wijnen AJ, Bagheri L, Badreldin AA, Larson AN, Dudakovic A, Thaler R, Paradise CR, Wu Z. Biological functions of chromobox (CBX) proteins in stem cell self-renewal, lineage-commitment, cancer and development. Bone 2021; 143:115659. [PMID: 32979540 DOI: 10.1016/j.bone.2020.115659] [Citation(s) in RCA: 54] [Impact Index Per Article: 18.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 09/02/2020] [Accepted: 09/21/2020] [Indexed: 02/06/2023]
Abstract
Epigenetic regulatory proteins support mammalian development, cancer, aging and tissue repair by controlling many cellular processes including stem cell self-renewal, lineage-commitment and senescence in both skeletal and non-skeletal tissues. We review here our knowledge of epigenetic regulatory protein complexes that support the formation of inaccessible heterochromatin and suppress expression of cell and tissue-type specific biomarkers during development. Maintenance and formation of heterochromatin critically depends on epigenetic regulators that recognize histone 3 lysine trimethylation at residues K9 and K27 (respectively, H3K9me3 and H3K27me3), which represent transcriptionally suppressive epigenetic marks. Three chromobox proteins (i.e., CBX1, CBX3 or CBX5) associated with the heterochromatin protein 1 (HP1) complex are methyl readers that interpret H3K9me3 marks which are mediated by H3K9 methyltransferases (i.e., SUV39H1 or SUV39H2). Other chromobox proteins (i.e., CBX2, CBX4, CBX6, CBX7 and CBX8) recognize H3K27me3, which is deposited by Polycomb Repressive Complex 2 (PRC2; a complex containing SUZ12, EED, RBAP46/48 and the methyl transferases EZH1 or EZH2). This second set of CBX proteins resides in PRC1, which has many subunits including other polycomb group factors (PCGF1, PCGF2, PCGF3, PCGF4, PCGF5, PCGF6), human polyhomeotic homologs (HPH1, HPH2, HPH3) and E3-ubiquitin ligases (RING1 or RING2). The latter enzymes catalyze the subsequent mono-ubiquitination of lysine 119 in H2A (H2AK119ub). We discuss biological, cellular and molecular functions of CBX proteins and their physiological and pathological activities in non-skeletal cells and tissues in anticipation of new discoveries on novel roles for CBX proteins in bone formation and skeletal development.
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Affiliation(s)
- Andre J van Wijnen
- Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, United States of America; Biochemistry & Molecular Biology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, United States of America; Center for Regenerative Medicine, Mayo Clinic, Rochester, MN, United States of America.
| | - Leila Bagheri
- Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, United States of America.
| | - Amr A Badreldin
- Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, United States of America.
| | - A Noelle Larson
- Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, United States of America.
| | - Amel Dudakovic
- Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, United States of America; Biochemistry & Molecular Biology, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, United States of America.
| | - Roman Thaler
- Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, United States of America.
| | - Christopher R Paradise
- Center for Regenerative Medicine, Mayo Clinic, Rochester, MN, United States of America; Mayo Clinic Graduate School of Biomedical Sciences, Mayo Clinic, Rochester, MN, United States of America
| | - Zhong Wu
- Department of Orthopedic Surgery, Mayo Clinic College of Medicine, Mayo Clinic, Rochester, MN, United States of America
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20
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Xu Y, Pan S, Song Y, Pan C, Chen C, Zhu X. The Prognostic Value of the Chromobox Family in Human Ovarian Cancer. J Cancer 2020; 11:5198-5209. [PMID: 32742466 PMCID: PMC7378907 DOI: 10.7150/jca.44475] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Accepted: 06/15/2020] [Indexed: 12/18/2022] Open
Abstract
Ovarian cancer is one of the most lethal gynecologic tumors in women and has a poor prognosis. The purpose of our study was to identify new prognostic markers in ovarian cancer. We examined the prognostic roles of mRNA expression of the chromobox (CBX) family in patients with ovarian cancer utilizing the Kaplan-Meier plotter database. The prognostic values and expression levels of CBX members associated with prognosis were further evaluated using KM plotter in diverse subgroups and immunohistochemistry (IHC) analysis in ovarian carcinoma. The results revealed that elevated CBX1-3 mRNA expression may predict poor overall survival (OS) and progression-free survival (PFS) outcomes in patients with ovarian cancer. Notably, in women with ovarian cancer, increased CBX1 mRNA expression was linked to a short OS in all stages and in the grade II and grade III subgroups. Additionally, CBX2 and CBX3 were strongly related to short OS in stage III+IV patients, and a link between high CBX3 mRNA expression and unfavorable OS in grade II patients was observed. High expression levels of CBX1 and CBX3 were significantly associated with chemotherapy resistance in ovarian cancer patients. IHC staining showed that the CBX1-3 proteins were upregulated in serous ovarian carcinoma tissues compared with normal ovarian tissues. Therefore, our results indicated that CBX1-3 could be attractive biomarkers for predicting poor prognosis of ovarian cancer.
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Affiliation(s)
- Yichi Xu
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Shuya Pan
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Yizuo Song
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Chunyu Pan
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Cheng Chen
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
| | - Xueqiong Zhu
- Department of Obstetrics and Gynecology, The Second Affiliated Hospital of Wenzhou Medical University, Wenzhou, China
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21
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Kumar A, Kono H. Heterochromatin protein 1 (HP1): interactions with itself and chromatin components. Biophys Rev 2020; 12:387-400. [PMID: 32144738 PMCID: PMC7242596 DOI: 10.1007/s12551-020-00663-y] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2020] [Accepted: 02/23/2020] [Indexed: 12/12/2022] Open
Abstract
Isoforms of heterochromatin protein 1 (HP1) have been known to perform a multitude of functions ranging from gene silencing, gene activation to cell cycle regulation, and cell differentiation. This functional diversity arises from the dissimilarities coded in protein sequence which confers different biophysical and biochemical properties to individual structural elements of HP1 and thereby different behavior and interaction patterns. Hence, an understanding of various interactions of the structural elements of HP1 will be of utmost importance to better elucidate chromatin dynamics in its presence. In this review, we have gathered available information about interactions of HP1 both within and with itself as well as with chromatin elements. Also, the possible implications of these interactions are discussed.
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Affiliation(s)
- Amarjeet Kumar
- Molecular Modelling and Simulation (MMS) Group, Institute for Quantum Life Science (iQLS), National Institutes for Quantum and Radiological Science and Technology (QST), Kizugawa, Kyoto, 619-0215, Japan
| | - Hidetoshi Kono
- Molecular Modelling and Simulation (MMS) Group, Institute for Quantum Life Science (iQLS), National Institutes for Quantum and Radiological Science and Technology (QST), Kizugawa, Kyoto, 619-0215, Japan.
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22
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Uribe-Etxebarria V, García-Gallastegui P, Pérez-Garrastachu M, Casado-Andrés M, Irastorza I, Unda F, Ibarretxe G, Subirán N. Wnt-3a Induces Epigenetic Remodeling in Human Dental Pulp Stem Cells. Cells 2020; 9:cells9030652. [PMID: 32156036 PMCID: PMC7140622 DOI: 10.3390/cells9030652] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Revised: 02/28/2020] [Accepted: 03/04/2020] [Indexed: 12/13/2022] Open
Abstract
Dental pulp stem cells (DPSCs) from adult teeth show the expression of a very complete repertoire of stem pluripotency core factors and a high plasticity for cell reprogramming. Canonical Wnt and Notch signaling pathways regulate stemness and the expression of pluripotency core factors in DPSCs, and even very short-term (48 h) activations of the Wnt pathway induce a profound remodeling of DPSCs at the physiologic and metabolic levels. In this work, DPSC cultures were exposed to treatments modulating Notch and Wnt signaling, and also induced to differentiate to osteo/adipocytes. DNA methylation, histone acetylation, histone methylation, and core factor expression levels where assessed by mass spectroscopy, Western blot, and qPCR. A short-term activation of Wnt signaling by WNT-3A induced a genomic DNA demethylation, and increased histone acetylation and histone methylation in DPSCs. The efficiency of cell reprogramming methods relies on the ability to surpass the epigenetic barrier, which determines cell lineage specificity. This study brings important information about the regulation of the epigenetic barrier by Wnt signaling in DPSCs, which could contribute to the development of safer and less aggressive reprogramming methodologies with a view to cell therapy.
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Affiliation(s)
- Verónica Uribe-Etxebarria
- Cell Biology and Histology Department, University of the Basque Country (UPV/EHU), Barrio Sarriena, S/N, 48940 Leioa, Spain; (V.U.-E.); (P.G.-G.); (M.P.-G.); (M.C.-A.); (I.I.); (F.U.)
- Pathology Department, New York University, 550 1st Avenue, New York, NY 10016, USA
| | - Patricia García-Gallastegui
- Cell Biology and Histology Department, University of the Basque Country (UPV/EHU), Barrio Sarriena, S/N, 48940 Leioa, Spain; (V.U.-E.); (P.G.-G.); (M.P.-G.); (M.C.-A.); (I.I.); (F.U.)
| | - Miguel Pérez-Garrastachu
- Cell Biology and Histology Department, University of the Basque Country (UPV/EHU), Barrio Sarriena, S/N, 48940 Leioa, Spain; (V.U.-E.); (P.G.-G.); (M.P.-G.); (M.C.-A.); (I.I.); (F.U.)
| | - María Casado-Andrés
- Cell Biology and Histology Department, University of the Basque Country (UPV/EHU), Barrio Sarriena, S/N, 48940 Leioa, Spain; (V.U.-E.); (P.G.-G.); (M.P.-G.); (M.C.-A.); (I.I.); (F.U.)
- Unité Mixte de Recherche UMR1029. INSERM-Université de Bordeaux, 33000 Bordeaux, France
| | - Igor Irastorza
- Cell Biology and Histology Department, University of the Basque Country (UPV/EHU), Barrio Sarriena, S/N, 48940 Leioa, Spain; (V.U.-E.); (P.G.-G.); (M.P.-G.); (M.C.-A.); (I.I.); (F.U.)
| | - Fernando Unda
- Cell Biology and Histology Department, University of the Basque Country (UPV/EHU), Barrio Sarriena, S/N, 48940 Leioa, Spain; (V.U.-E.); (P.G.-G.); (M.P.-G.); (M.C.-A.); (I.I.); (F.U.)
| | - Gaskon Ibarretxe
- Cell Biology and Histology Department, University of the Basque Country (UPV/EHU), Barrio Sarriena, S/N, 48940 Leioa, Spain; (V.U.-E.); (P.G.-G.); (M.P.-G.); (M.C.-A.); (I.I.); (F.U.)
- Correspondence: ; Tel.: +34-94-601-3218
| | - Nerea Subirán
- Physiology Department, University of the Basque Country (UPV/EHU), Barrio Sarriena, S/N, 48940 Leioa, Spain;
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The mouse HP1 proteins are essential for preventing liver tumorigenesis. Oncogene 2020; 39:2676-2691. [PMID: 32020053 DOI: 10.1038/s41388-020-1177-8] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 01/06/2020] [Accepted: 01/21/2020] [Indexed: 12/16/2022]
Abstract
Chromatin organization is essential for appropriate interpretation of the genetic information. Here, we demonstrated that the chromatin-associated proteins HP1 are dispensable for hepatocytes survival but are essential within hepatocytes to prevent liver tumor development in mice with HP1β being pivotal in these functions. Yet, we found that the loss of HP1 per se is not sufficient to induce cell transformation but renders cells more resistant to specific stress such as the expression of oncogenes and thus in fine, more prone to cell transformation. Molecular characterization of HP1-Triple KO premalignant livers and BMEL cells revealed that HP1 are essential for the maintenance of heterochromatin organization and for the regulation of specific genes with most of them having well characterized functions in liver functions and homeostasis. We further showed that some specific retrotransposons get reactivated upon loss of HP1, correlating with overexpression of genes in their neighborhood. Interestingly, we found that, although HP1-dependent genes are characterized by enrichment H3K9me3, this mark does not require HP1 for its maintenance and is not sufficient to maintain gene repression in absence of HP1. Finally, we demonstrated that the loss of TRIM28 association with HP1 recapitulated several phenotypes induced by the loss of HP1 including the reactivation of some retrotransposons and the increased incidence of liver cancer development. Altogether, our findings indicate that HP1 proteins act as guardians of liver homeostasis to prevent tumor development by modulating multiple chromatin-associated events within both the heterochromatic and euchromatic compartments, partly through regulation of the corepressor TRIM28 activity.
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Singh PB, Newman AG. On the relations of phase separation and Hi-C maps to epigenetics. ROYAL SOCIETY OPEN SCIENCE 2020; 7:191976. [PMID: 32257349 PMCID: PMC7062049 DOI: 10.1098/rsos.191976] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 02/03/2020] [Indexed: 05/10/2023]
Abstract
The relationship between compartmentalization of the genome and epigenetics is long and hoary. In 1928, Heitz defined heterochromatin as the largest differentiated chromatin compartment in eukaryotic nuclei. Müller's discovery of position-effect variegation in 1930 went on to show that heterochromatin is a cytologically visible state of heritable (epigenetic) gene repression. Current insights into compartmentalization have come from a high-throughput top-down approach where contact frequency (Hi-C) maps revealed the presence of compartmental domains that segregate the genome into heterochromatin and euchromatin. It has been argued that the compartmentalization seen in Hi-C maps is owing to the physiochemical process of phase separation. Oddly, the insights provided by these experimental and conceptual advances have remained largely silent on how Hi-C maps and phase separation relate to epigenetics. Addressing this issue directly in mammals, we have made use of a bottom-up approach starting with the hallmarks of constitutive heterochromatin, heterochromatin protein 1 (HP1) and its binding partner the H3K9me2/3 determinant of the histone code. They are key epigenetic regulators in eukaryotes. Both hallmarks are also found outside mammalian constitutive heterochromatin as constituents of larger (0.1-5 Mb) heterochromatin-like domains and smaller (less than 100 kb) complexes. The well-documented ability of HP1 proteins to function as bridges between H3K9me2/3-marked nucleosomes contributes to polymer-polymer phase separation that packages epigenetically heritable chromatin states during interphase. Contacts mediated by HP1 'bridging' are likely to have been detected in Hi-C maps, as evidenced by the B4 heterochromatic subcompartment that emerges from contacts between large KRAB-ZNF heterochromatin-like domains. Further, mutational analyses have revealed a finer, innate, compartmentalization in Hi-C experiments that probably reflect contacts involving smaller domains/complexes. Proteins that bridge (modified) DNA and histones in nucleosomal fibres-where the HP1-H3K9me2/3 interaction represents the most evolutionarily conserved paradigm-could drive and generate the fundamental compartmentalization of the interphase nucleus. This has implications for the mechanism(s) that maintains cellular identity, be it a terminally differentiated fibroblast or a pluripotent embryonic stem cell.
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Affiliation(s)
- Prim B. Singh
- Nazarbayev University School of Medicine, 5/1 Kerei, Zhanibek Khandar Street, Nur-Sultan Z05K4F4, Kazakhstan
- Epigenetics Laboratory, Department of Natural Sciences, Novosibirsk State University, Pirogov Street 2, Novosibirsk 630090, Russian Federation
| | - Andrew G. Newman
- Institute of Cell and Neurobiology, Charité—Universitätsmedizin Berlin, Corporate member of Freie Universität Berlin, Humboldt-Universität zu Berlin and Berlin Institute of Health, Berlin, Germany
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25
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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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26
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Cockova Z, Ujcikova H, Telensky P, Novotny J. Protein profiling of SH-SY5Y neuroblastoma cells: The effect of rhein. J Biosci 2019; 44:88. [PMID: 31502566] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
4,5-Dihydroxyanthraquinone-2-carboxylic acid (Rhein) has been shown to have various physiological and pharmacological properties including anticancer activity and modulatory effects on bioenergetics. In this study, we explored the impact of rhein on protein profiling of undifferentiated (UC) and differentiated (DC) SH-SY5Y cells. Besides that, the cellular morphology and expression of differentiation markers were investigated to determine the effect of rhein on retinoic acidinduced neuronal cell differentiation. Using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ ionization-time-of-flight mass spectrometry we evaluated the changes in the proteome of both UC and DC SH-SY5Y cells after 24 h treatment with rhein. Validation of selected differentially expressed proteins and the assessment of neuronal differentiation markers were performed by western blotting. Proteomic analysis revealed significant changes in the abundance of 15 proteins linked to specific cellular processes such as cytoskeleton structure and regulation, mitochondrial function, energy metabolism, protein synthesis and neuronal plasticity. We also observed that the addition of rhein to the cultured cells during differentiation resulted in a significantly reduced neurite outgrowth and decreased expression of neuronal markers. These results indicate that rhein may strongly interfere with the differentiation process of SH-SY5Y neuroblastoma cells and is capable of inducing marked proteomic changes in these cells.
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Affiliation(s)
- Zuzana Cockova
- Department of Physiology, Faculty of Science, Charles University, Prague, Czech Republic
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27
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Cockova Z, Ujcikova H, Telensky P, Novotny J. Protein profiling of SH-SY5Y neuroblastoma cells: The effect of rhein. J Biosci 2019. [DOI: 10.1007/s12038-019-9908-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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28
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Francipane MG, Bulanin D, Lagasse E. Establishment and Characterization of 5-Fluorouracil-Resistant Human Colorectal Cancer Stem-Like Cells: Tumor Dynamics under Selection Pressure. Int J Mol Sci 2019; 20:ijms20081817. [PMID: 31013771 PMCID: PMC6515384 DOI: 10.3390/ijms20081817] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2019] [Revised: 03/21/2019] [Accepted: 04/09/2019] [Indexed: 12/20/2022] Open
Abstract
5-Fluorouracil (5-FU) remains the gold standard of first-line treatment for colorectal cancer (CRC). Although it may initially debulk the tumor mass, relapses frequently occur, indicating the existence of cancer cells that are therapy-resistant and are capable of refueling tumor growth. To identify mechanisms of drug resistance, CRC stem-like cells were subjected to long-term 5-FU selection using either intermittent treatment regimen with the IC50 drug dose or continuous treatment regimen with escalating drug doses. Parental cancer cells were cultivated in parallel. Real-time PCR arrays and bioinformatic tools were used to investigate gene expression changes. We found the first method selected for cancer cells with more aggressive features. We therefore transplanted these cancer cells or parental cells in mice, and again, found that not only did the 5-FU-selected cancer cells generate more aggressive tumors with respect to their parental counterpart, but they also showed a different gene expression pattern as compared to what we had observed in vitro, with ID1 the top upregulated gene. We propose ID1 as a stemness marker pervasively expressed in secondary lesions emerging after completion of chemotherapy.
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Affiliation(s)
- Maria Giovanna Francipane
- McGowan Institute for Regenerative Medicine and Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
- Ri.MED Foundation, 90133 Palermo, Italy.
| | - Denis Bulanin
- Department of Biomedical Sciences, Nazarbayev University School of Medicine, Astana 010000, Kazakhstan.
| | - Eric Lagasse
- McGowan Institute for Regenerative Medicine and Department of Pathology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15219, USA.
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29
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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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30
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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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31
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Arbach HE, Harland-Dunaway M, Chang JK, Wills AE. Extreme nuclear branching in healthy epidermal cells of the Xenopus tail fin. J Cell Sci 2018; 131:jcs.217513. [PMID: 30131443 DOI: 10.1242/jcs.217513] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 08/10/2018] [Indexed: 01/09/2023] Open
Abstract
Changes in nuclear morphology contribute to the regulation of complex cell properties, including differentiation and tissue elasticity. Perturbations of nuclear morphology are associated with pathologies that include progeria, cancer and muscular dystrophy. The mechanisms governing nuclear shape changes in healthy cells remain poorly understood, partially because there are few models of nuclear shape variation in healthy cells. Here, we introduce nuclear branching in epidermal fin cells of Xenopus tropicalis as a model for extreme variation of nuclear morphology in a diverse population of healthy cells. We found that nuclear branching arises within these cells and becomes more elaborate during embryonic development. These cells contain broadly distributed marks of transcriptionally active chromatin and heterochromatin, and have active cell cycles. We found that nuclear branches are disrupted by loss of filamentous actin and depend on epidermal expression of the nuclear lamina protein Lamin B1. Inhibition of nuclear branching disrupts fin morphology, suggesting that nuclear branching may be involved in fin development. This study introduces the nuclei of the Xenopus fin as a powerful new model for extreme nuclear morphology in healthy cells to complement studies of nuclear shape variation in pathological contexts.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Hannah E Arbach
- Department of Biochemistry, University of Washington, Seattle, WA 98195-3750, USA
| | | | - Jessica K Chang
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Andrea E Wills
- Department of Biochemistry, University of Washington, Seattle, WA 98195-3750, USA
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32
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E3 ubiquitin ligase HECW2 mediates the proteasomal degradation of HP1 isoforms. Biochem Biophys Res Commun 2018; 503:2478-2484. [DOI: 10.1016/j.bbrc.2018.07.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 07/02/2018] [Indexed: 12/12/2022]
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33
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Yang YF, Pan YH, Tian QH, Wu DC, Su SG. CBX1 Indicates Poor Outcomes and Exerts Oncogenic Activity in Hepatocellular Carcinoma. Transl Oncol 2018; 11:1110-1118. [PMID: 30031230 PMCID: PMC6074001 DOI: 10.1016/j.tranon.2018.07.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2018] [Revised: 06/26/2018] [Accepted: 07/02/2018] [Indexed: 12/13/2022] Open
Abstract
Dysregulation of chromobox proteins contributes to the progression of human diseases. CBX1 has been implicated in epigenetic control of chromatin structure and gene expression, but its role in human cancers remains largely unknown. Here we show that CBX1 exhibits oncogenic activities in hepatocellular carcinoma (HCC) and indicates poor outcomes. The expression of CBX1 was noticeably increased, at both mRNA and protein levels, in HCC tissues and cell lines, compared with the nontumorous ones. High CBX1 expression was significantly associated with larger tumor size, poor tumor differentiation and tumor vascular invasion. Patients with elevated expression of CBX1 were frequently accompanied with unfavorable overall and disease-free survivals in two independent cohorts consisting of 648 HCC cases. The prognostic value of CBX1 was further confirmed by stratified survival analyses. Multivariate cox regression model suggested CBX1 as an independent factor for overall survival (hazard ratio = 1.735, 95% confident interval: 1.342–2.244, P < .001). In vitro data demonstrated that CBX1 overexpression promoted cell proliferation and migration, whereas the knockdown of CBX1 resulted in the opposite phenotypes. Mechanistically, CBX1 interacted with transcription factor HMGA2 to activate the Wnt/β-Catenin signaling pathway. Suppression of β-Catenin by siRNA or specific inhibitor XAV-939 markedly attenuated CBX1-mediated cell growth. Collectively, our findings indicate that CBX1 functions as an oncogene and may serve as a potential prognostic biomarker in HCC.
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Affiliation(s)
- Yu-Feng Yang
- Department of Pathology, Dongguan Third People's Hospital, Dongguan, China
| | - Ying-Hua Pan
- Department of Rheumatology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Qiu-Hong Tian
- Department of Oncology, First Affiliated Hospital of NanChang University, NanChang, Jiangxi 330006, China
| | - Dan-Chun Wu
- Department of Rheumatology, The Third Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Shu-Guang Su
- Department of Pathology, The Affiliated Hexian Memorial Hospital of Southern Medical University, Guangzhou, China.
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Ding ZH, Qi J, Shang AQ, Zhang YJ, Wei J, Hu LQ, Wang WW, Yang M. Docking of CDK1 with antibiotic drugs revealed novel therapeutic value in breast ductal cancer in situ. Oncotarget 2017; 8:61998-62010. [PMID: 28977921 PMCID: PMC5617481 DOI: 10.18632/oncotarget.18779] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2017] [Accepted: 05/07/2017] [Indexed: 01/08/2023] Open
Abstract
The aim of our research is to identify potential genes associated with Ductal carcinoma in situ (DCIS) through microarrays. The microarray dataset GS54665 were downloaded from the GEO(Gene Expression Omnibus) database. Dysregulated genes were screened and their associations with DCIS was analyzed by comprehensive bioinformatics tools. A total of 649 differential expression genes were identified between normal and DCIS samples, including 224 up-regulated genes and 425 down-regulated genes. Biological process annotation and pathway enrichment analysis identified several DCIS-related signaling pathways. Finally, PPI network was constructed with String website in order to get the hub codes involved in Ductal carcinoma in situ. We thus concluded that Five genes: CDK1, CCNB2, MAD2L1, PPARG, ACACB were finally identified to participate in the regulation and serve as potential diagnosis signatures in in Ductal carcinoma in situ. Finally, complmentarity between CDK1 and three drugs, Aminophenazone, Pomalidomide and the Rosoxacin, implies novel pharmacological value of those drugs in breast cancer.
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Affiliation(s)
- Zhong-Hai Ding
- Department of Senior Cadres' Healthcare, Jinling Hospital, Medical School of Nanjing University, Nanjing 210002, Jiangsu, China
| | - Jia Qi
- Department of Dermatology, Nanjing Medical University Affiliated Wuxi Second Hospital, Wuxi 214002, Jiangsu, China
| | - An-Quan Shang
- Department of Laboratory Medicine, Tongji Hospital of Tongji University, Shanghai 200092, Shanghai, China.,The Sixth People's Hospital of Yancheng City, Yancheng 224005, Jiangsu, China
| | - Yu-Jie Zhang
- Clinical Medicine School, Ningxia Medical University, Yinchuan 750004, Ningxia, China
| | - Jun Wei
- Clinical Medicine School, Ningxia Medical University, Yinchuan 750004, Ningxia, China
| | - Li-Qing Hu
- Department of Laboratory Medicine, The first Hospital of Ningbo City, Ningbo 315010, Zhejiang, China
| | - Wei-Wei Wang
- Department of Pathology, The First People's Hospital of Yancheng City and The Sixth People's Hospital of Yancheng City, Yancheng 224001, Jiangsu, China
| | - Man Yang
- Department of Laboratory Medicine, TCM Hospital of Yancheng City Affiliated to Nanjing University of Chinese Medicine, Yancheng 224001, Jiangsu, China
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35
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Meka SRK, Chacko LA, Ravi A, Chatterjee K, Ananthanarayanan V. Role of Microtubules in Osteogenic Differentiation of Mesenchymal Stem Cells on 3D Nanofibrous Scaffolds. ACS Biomater Sci Eng 2017; 3:551-559. [DOI: 10.1021/acsbiomaterials.6b00725] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Sai Rama Krishna Meka
- Department
of Materials Engineering and §Centre for BioSystems Science and
Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Leeba Ann Chacko
- Department
of Materials Engineering and §Centre for BioSystems Science and
Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Ashwini Ravi
- Department
of Materials Engineering and §Centre for BioSystems Science and
Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Kaushik Chatterjee
- Department
of Materials Engineering and §Centre for BioSystems Science and
Engineering, Indian Institute of Science, Bangalore 560012, India
| | - Vaishnavi Ananthanarayanan
- Department
of Materials Engineering and §Centre for BioSystems Science and
Engineering, Indian Institute of Science, Bangalore 560012, India
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Molitor J, Mallm JP, Rippe K, Erdel F. Retrieving Chromatin Patterns from Deep Sequencing Data Using Correlation Functions. Biophys J 2017; 112:473-490. [PMID: 28131315 DOI: 10.1016/j.bpj.2017.01.001] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2016] [Revised: 11/30/2016] [Accepted: 01/04/2017] [Indexed: 01/31/2023] Open
Abstract
Epigenetic modifications and other chromatin features partition the genome on multiple length scales. They define chromatin domains with distinct biological functions that come in sizes ranging from single modified DNA bases to several megabases in the case of heterochromatic histone modifications. Due to chromatin folding, domains that are well separated along the linear nucleosome chain can form long-range interactions in three-dimensional space. It has now become a routine task to map epigenetic marks and chromatin structure by deep sequencing methods. However, assessing and comparing the properties of chromatin domains and their positional relationships across data sets without a priori assumptions remains challenging. Here, we introduce multiscale correlation evaluation (MCORE), which uses the fluctuation spectrum of mapped sequencing reads to quantify and compare chromatin patterns over a broad range of length scales in a model-independent manner. We applied MCORE to map the chromatin landscape in mouse embryonic stem cells and differentiated neural cells. We integrated sequencing data from chromatin immunoprecipitation, RNA expression, DNA methylation, and chromosome conformation capture experiments into network models that reflect the positional relationships among these features on different genomic scales. Furthermore, we used MCORE to compare our experimental data to models for heterochromatin reorganization during differentiation. The application of correlation functions to deep sequencing data complements current evaluation schemes and will support the development of quantitative descriptions of chromatin networks.
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Affiliation(s)
- Jana Molitor
- German Cancer Research Center (DKFZ) and Bioquant, Research Group Genome Organization & Function, Heidelberg, Germany
| | - Jan-Philipp Mallm
- German Cancer Research Center (DKFZ) and Bioquant, Research Group Genome Organization & Function, Heidelberg, Germany
| | - Karsten Rippe
- German Cancer Research Center (DKFZ) and Bioquant, Research Group Genome Organization & Function, Heidelberg, Germany.
| | - Fabian Erdel
- German Cancer Research Center (DKFZ) and Bioquant, Research Group Genome Organization & Function, Heidelberg, Germany.
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Pillitteri LJ, Guo X, Dong J. Asymmetric cell division in plants: mechanisms of symmetry breaking and cell fate determination. Cell Mol Life Sci 2016; 73:4213-4229. [PMID: 27286799 PMCID: PMC5522748 DOI: 10.1007/s00018-016-2290-2] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 06/02/2016] [Accepted: 06/02/2016] [Indexed: 02/07/2023]
Abstract
Asymmetric cell division is a fundamental mechanism that generates cell diversity while maintaining self-renewing stem cell populations in multicellular organisms. Both intrinsic and extrinsic mechanisms underpin symmetry breaking and differential daughter cell fate determination in animals and plants. The emerging picture suggests that plants deal with the problem of symmetry breaking using unique cell polarity proteins, mobile transcription factors, and cell wall components to influence asymmetric divisions and cell fate. There is a clear role for altered auxin distribution and signaling in distinguishing two daughter cells and an emerging role for epigenetic modifications through chromatin remodelers and DNA methylation in plant cell differentiation. The importance of asymmetric cell division in determining final plant form provides the impetus for its study in the areas of both basic and applied science.
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Affiliation(s)
- Lynn Jo Pillitteri
- Department of Biology, Western Washington University, Bellingham, WA, 98225, USA
| | - Xiaoyu Guo
- Waksman Institute of Microbiology, Rutgers the State University of New Jersey, Piscataway, NJ, 08854, USA
| | - Juan Dong
- Waksman Institute of Microbiology, Rutgers the State University of New Jersey, Piscataway, NJ, 08854, USA.
- Department of Plant Biology and Pathology, Rutgers the State University of New Jersey, New Brunswick, NJ, 08901, USA.
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Eck S, Wörz S, Müller-Ott K, Hahn M, Biesdorf A, Schotta G, Rippe K, Rohr K. A spherical harmonics intensity model for 3D segmentation and 3D shape analysis of heterochromatin foci. Med Image Anal 2016; 32:18-31. [DOI: 10.1016/j.media.2016.03.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 03/07/2016] [Accepted: 03/09/2016] [Indexed: 12/01/2022]
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Gonzalez-Sandoval A, Gasser SM. Mechanism of chromatin segregation to the nuclear periphery in C. elegans embryos. WORM 2016; 5:e1190900. [PMID: 27695653 DOI: 10.1080/21624054.2016.1190900] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 05/06/2016] [Accepted: 05/13/2016] [Indexed: 10/21/2022]
Abstract
In eukaryotic organisms, gene regulation occurs in the context of chromatin. In the interphase nucleus, euchromatin and heterochromatin occupy distinct space during cell differentiation, with heterochromatin becoming enriched at the nuclear and nucleolar peripheries. This organization is thought to fine-tune gene expression. To elucidate the mechanisms that govern this level of genome organization, screens were carried out in C. elegans which monitored the loss of heterochromatin sequestration at the nuclear periphery. This led to the identification of a novel chromodomain protein, CEC-4 (Caenorhabditis elegans chromodomain protein 4) that mediates the anchoring of H3K9 methylation-bearing chromatin at the nuclear periphery in early to mid-stage embryos. Surprisingly, the loss of CEC-4 does not derepress genes found in heterochromatic domains, nor does it affect differentiation under standard laboratory conditions. On the other hand, CEC-4 contributes to the efficiency with which muscle differentiation is induced following ectopic expression of the master regulator, HLH-1. This is one of the first phenotypes specifically attributed to the ablation of heterochromatin anchoring.
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Affiliation(s)
- Adriana Gonzalez-Sandoval
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland; Faculty of Natural Sciences, University of Basel, Basel, Switzerland
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland; Faculty of Natural Sciences, University of Basel, Basel, Switzerland
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40
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Novo CL, Tang C, Ahmed K, Djuric U, Fussner E, Mullin NP, Morgan NP, Hayre J, Sienerth AR, Elderkin S, Nishinakamura R, Chambers I, Ellis J, Bazett-Jones DP, Rugg-Gunn PJ. The pluripotency factor Nanog regulates pericentromeric heterochromatin organization in mouse embryonic stem cells. Genes Dev 2016; 30:1101-15. [PMID: 27125671 PMCID: PMC4863740 DOI: 10.1101/gad.275685.115] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2015] [Accepted: 03/23/2016] [Indexed: 12/31/2022]
Abstract
Here, Novo et al. identify a new critical role for the transcription factor Nanog in maintaining an open heterochromatin state in pluripotent mouse embryonic stem cells and demonstrate that forced expression of Nanog is sufficient to remodel and decondense chromatin in more developmentally advanced mammalian cell types. This study delineates a direct connection between the pluripotency network and chromatin organization and shows that maintainence of an open heterochromatin architecture is highly regulated in embryonic stem cells. An open and decondensed chromatin organization is a defining property of pluripotency. Several epigenetic regulators have been implicated in maintaining an open chromatin organization, but how these processes are connected to the pluripotency network is unknown. Here, we identified a new role for the transcription factor NANOG as a key regulator connecting the pluripotency network with constitutive heterochromatin organization in mouse embryonic stem cells. Deletion of Nanog leads to chromatin compaction and the remodeling of heterochromatin domains. Forced expression of NANOG in epiblast stem cells is sufficient to decompact chromatin. NANOG associates with satellite repeats within heterochromatin domains, contributing to an architecture characterized by highly dispersed chromatin fibers, low levels of H3K9me3, and high major satellite transcription, and the strong transactivation domain of NANOG is required for this organization. The heterochromatin-associated protein SALL1 is a direct cofactor for NANOG, and loss of Sall1 recapitulates the Nanog-null phenotype, but the loss of Sall1 can be circumvented through direct recruitment of the NANOG transactivation domain to major satellites. These results establish a direct connection between the pluripotency network and chromatin organization and emphasize that maintaining an open heterochromatin architecture is a highly regulated process in embryonic stem cells.
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Affiliation(s)
- Clara Lopes Novo
- Epigenetics Programme, The Babraham Institute, Cambridge CB22 3AT, United Kingdom
| | - Calvin Tang
- Program in Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario MSG 1L7, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Kashif Ahmed
- Program in Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario MSG 1L7, Canada
| | - Ugljesa Djuric
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Eden Fussner
- Program in Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario MSG 1L7, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Nicholas P Mullin
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - Natasha P Morgan
- Epigenetics Programme, The Babraham Institute, Cambridge CB22 3AT, United Kingdom
| | - Jasvinder Hayre
- Epigenetics Programme, The Babraham Institute, Cambridge CB22 3AT, United Kingdom
| | - Arnold R Sienerth
- Epigenetics Programme, The Babraham Institute, Cambridge CB22 3AT, United Kingdom
| | - Sarah Elderkin
- Nuclear Dynamics Programme, The Babraham Institute, Cambridge, CB22 3AT, United Kingdom
| | - Ryuichi Nishinakamura
- Department of Kidney Development, Institute of Molecular Embryology and Genetics, Kumamoto University, Kumamoto 860-0811, Japan
| | - Ian Chambers
- MRC Centre for Regenerative Medicine, Institute for Stem Cell Research, School of Biological Sciences, University of Edinburgh, Edinburgh EH16 4UU, United Kingdom
| | - James Ellis
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G 1L7, Canada; Department of Molecular Genetics, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - David P Bazett-Jones
- Program in Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario MSG 1L7, Canada; Department of Biochemistry, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Peter J Rugg-Gunn
- Epigenetics Programme, The Babraham Institute, Cambridge CB22 3AT, United Kingdom; Centre for Trophoblast Research, University of Cambridge, Cambridge CB2 3EG, United Kingdom; Wellcome Trust-Medical Research Council Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB2 1QR, United Kingdom
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Harr JC, Gonzalez-Sandoval A, Gasser SM. Histones and histone modifications in perinuclear chromatin anchoring: from yeast to man. EMBO Rep 2016; 17:139-55. [PMID: 26792937 PMCID: PMC4783997 DOI: 10.15252/embr.201541809] [Citation(s) in RCA: 102] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Accepted: 12/21/2015] [Indexed: 01/01/2023] Open
Abstract
It is striking that within a eukaryotic nucleus, the genome can assume specific spatiotemporal distributions that correlate with the cell's functional states. Cell identity itself is determined by distinct sets of genes that are expressed at a given time. On the level of the individual gene, there is a strong correlation between transcriptional activity and associated histone modifications. Histone modifications act by influencing the recruitment of non-histone proteins and by determining the level of chromatin compaction, transcription factor binding, and transcription elongation. Accumulating evidence also shows that the subnuclear position of a gene or domain correlates with its expression status. Thus, the question arises whether this spatial organization results from or determines a gene's chromatin status. Although the association of a promoter with the inner nuclear membrane (INM) is neither necessary nor sufficient for repression, the perinuclear sequestration of heterochromatin is nonetheless conserved from yeast to man. How does subnuclear localization influence gene expression? Recent work argues that the common denominator between genome organization and gene expression is the modification of histones and in some cases of histone variants. This provides an important link between local chromatin structure and long-range genome organization in interphase cells. In this review, we will evaluate how histones contribute to the latter, and discuss how this might help to regulate genes crucial for cell differentiation.
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Affiliation(s)
- Jennifer C Harr
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland
| | - Adriana Gonzalez-Sandoval
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland Faculty of Natural Sciences, University of Basel, Basel, Switzerland
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, Basel, Switzerland Faculty of Natural Sciences, University of Basel, Basel, Switzerland
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42
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Perinuclear Anchoring of H3K9-Methylated Chromatin Stabilizes Induced Cell Fate in C. elegans Embryos. Cell 2015; 163:1333-47. [PMID: 26607792 DOI: 10.1016/j.cell.2015.10.066] [Citation(s) in RCA: 144] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2015] [Revised: 10/07/2015] [Accepted: 10/27/2015] [Indexed: 01/24/2023]
Abstract
Interphase chromatin is organized in distinct nuclear sub-compartments, reflecting its degree of compaction and transcriptional status. In Caenorhabditis elegans embryos, H3K9 methylation is necessary to silence and to anchor repeat-rich heterochromatin at the nuclear periphery. In a screen for perinuclear anchors of heterochromatin, we identified a previously uncharacterized C. elegans chromodomain protein, CEC-4. CEC-4 binds preferentially mono-, di-, or tri-methylated H3K9 and localizes at the nuclear envelope independently of H3K9 methylation and nuclear lamin. CEC-4 is necessary for endogenous heterochromatin anchoring, but not for transcriptional repression, in contrast to other known H3K9 methyl-binders in worms, which mediate gene repression but not perinuclear anchoring. When we ectopically induce a muscle differentiation program in embryos, cec-4 mutants fail to commit fully to muscle cell fate. This suggests that perinuclear sequestration of chromatin during development helps restrict cell differentiation programs by stabilizing commitment to a specific cell fate. PAPERCLIP.
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Heterochromatin Protein 1β (HP1β) has distinct functions and distinct nuclear distribution in pluripotent versus differentiated cells. Genome Biol 2015; 16:213. [PMID: 26415775 PMCID: PMC4587738 DOI: 10.1186/s13059-015-0760-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2015] [Accepted: 08/25/2015] [Indexed: 11/22/2022] Open
Abstract
Background Pluripotent embryonic stem cells (ESCs) have the unique ability to differentiate into every cell type and to self-renew. These characteristics correlate with a distinct nuclear architecture, epigenetic signatures enriched for active chromatin marks and hyperdynamic binding of structural chromatin proteins. Recently, several chromatin-related proteins have been shown to regulate ESC pluripotency and/or differentiation, yet the role of the major heterochromatin proteins in pluripotency is unknown. Results Here we identify Heterochromatin Protein 1β (HP1β) as an essential protein for proper differentiation, and, unexpectedly, for the maintenance of pluripotency in ESCs. In pluripotent and differentiated cells HP1β is differentially localized and differentially associated with chromatin. Deletion of HP1β, but not HP1α, in ESCs provokes a loss of the morphological and proliferative characteristics of embryonic pluripotent cells, reduces expression of pluripotency factors and causes aberrant differentiation. However, in differentiated cells, loss of HP1β has the opposite effect, perturbing maintenance of the differentiation state and facilitating reprogramming to an induced pluripotent state. Microscopy, biochemical fractionation and chromatin immunoprecipitation reveal a diffuse nucleoplasmic distribution, weak association with chromatin and high expression levels for HP1β in ESCs. The minor fraction of HP1β that is chromatin-bound in ESCs is enriched within exons, unlike the situation in differentiated cells, where it binds heterochromatic satellite repeats and chromocenters. Conclusions We demonstrate an unexpected duality in the role of HP1β: it is essential in ESCs for maintaining pluripotency, while it is required for proper differentiation in differentiated cells. Thus, HP1β function both depends on, and regulates, the pluripotent state. Electronic supplementary material The online version of this article (doi:10.1186/s13059-015-0760-8) contains supplementary material, which is available to authorized users.
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44
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Mattout A, Cabianca DS, Gasser SM. Chromatin states and nuclear organization in development--a view from the nuclear lamina. Genome Biol 2015; 16:174. [PMID: 26303512 PMCID: PMC4549078 DOI: 10.1186/s13059-015-0747-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
The spatial distribution of chromatin domains in interphase nuclei changes dramatically during development in multicellular organisms. A crucial question is whether nuclear organization is a cause or a result of differentiation. Genetic perturbation of lamina–heterochromatin interactions is helping to reveal the cross-talk between chromatin states and nuclear organization.
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Affiliation(s)
- Anna Mattout
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058, Basel, Switzerland.
| | - Daphne S Cabianca
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058, Basel, Switzerland.
| | - Susan M Gasser
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, CH-4058, Basel, Switzerland. .,University of Basel, Faculty of Natural Sciences, Klingelbergstrasse 50, CH-4056, Basel, Switzerland.
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