1
|
Kotb NM, Ulukaya G, Chavan A, Nguyen SC, Proskauer L, Joyce E, Hasson D, Jagannathan M, Rangan P. Genome organization regulates nuclear pore complex formation and promotes differentiation during Drosophila oogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.15.567233. [PMID: 38014330 PMCID: PMC10680722 DOI: 10.1101/2023.11.15.567233] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Genome organization can regulate gene expression and promote cell fate transitions. The differentiation of germline stem cells (GSCs) to oocytes in Drosophila involves changes in genome organization mediated by heterochromatin and the nuclear pore complex (NPC). Heterochromatin represses germ-cell genes during differentiation and NPCs anchor these silenced genes to the nuclear periphery, maintaining silencing to allow for oocyte development. Surprisingly, we find that genome organization also contributes to NPC formation, mediated by the transcription factor Stonewall (Stwl). As GSCs differentiate, Stwl accumulates at boundaries between silenced and active gene compartments. Stwl at these boundaries plays a pivotal role in transitioning germ-cell genes into a silenced state and activating a group of oocyte genes and Nucleoporins (Nups). The upregulation of these Nups during differentiation is crucial for NPC formation and further genome organization. Thus, crosstalk between genome architecture and NPCs is essential for successful cell fate transitions.
Collapse
Affiliation(s)
- Noor M. Kotb
- Department of Biomedical Sciences/Wadsworth Center, University at Albany SUNY, Albany, NY 12202
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Gulay Ulukaya
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Tisch Cancer Institute Bioinformatics for Next Generation Sequencing (BiNGS) core
| | - Ankita Chavan
- Department of Biology, Institute of Biochemistry, ETH Zurich, 8092 Zurich
| | - Son C. Nguyen
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104
| | - Lydia Proskauer
- Department of Biological Sciences/RNA Institute, University at Albany SUNY, Albany, NY 12202
- Current address: Biochemistry and Molecular Biology Department, University of Massachusetts Amherst, Amherst, MA 01003
| | - Eric Joyce
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104
| | - Dan Hasson
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Tisch Cancer Institute Bioinformatics for Next Generation Sequencing (BiNGS) core
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Madhav Jagannathan
- Department of Biology, Institute of Biochemistry, ETH Zurich, 8092 Zurich
| | - Prashanth Rangan
- Department of Cell, Developmental, and Regenerative Biology, Black Family Stem Cell Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| |
Collapse
|
2
|
Kumar P, Gholamalamdari O, Zhang Y, Zhang L, Vertii A, van Schaik T, Peric-Hupkes D, Sasaki T, Gilbert DM, van Steensel B, Ma J, Kaufman PD, Belmont AS. Nucleolus and centromere TSA-Seq reveals variable localization of heterochromatin in different cell types. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.29.564613. [PMID: 37961445 PMCID: PMC10634939 DOI: 10.1101/2023.10.29.564613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Genome differential positioning within interphase nuclei remains poorly explored. We extended and validated TSA-seq to map genomic regions near nucleoli and pericentric heterochromatin in four human cell lines. Our study confirmed that smaller chromosomes localize closer to nucleoli but further deconvolved this by revealing a preference for chromosome arms below 36-46 Mbp in length. We identified two lamina associated domain subsets through their differential nuclear lamina versus nucleolar positioning in different cell lines which showed distinctive patterns of DNA replication timing and gene expression across all cell lines. Unexpectedly, active, nuclear speckle-associated genomic regions were found near typically repressive nuclear compartments, which is attributable to the close proximity of nuclear speckles and nucleoli in some cell types, and association of centromeres with nuclear speckles in hESCs. Our study points to a more complex and variable nuclear genome organization than suggested by current models, as revealed by our TSA-seq methodology.
Collapse
|
3
|
Lee H, Seo P, Teklay S, Yuguchi E, Benetta ED, Werren JH, Ferree PM. Ability of a selfish B chromosome to evade genome elimination in the jewel wasp, Nasonia vitripennis. Heredity (Edinb) 2023; 131:230-237. [PMID: 37524915 PMCID: PMC10462710 DOI: 10.1038/s41437-023-00639-0] [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: 03/15/2023] [Revised: 07/04/2023] [Accepted: 07/09/2023] [Indexed: 08/02/2023] Open
Abstract
B chromosomes are non-essential, extra chromosomes that can exhibit transmission-enhancing behaviors, including meiotic drive, mitotic drive, and induction of genome elimination, in plants and animals. A fundamental but poorly understood question is what characteristics allow B chromosomes to exhibit these extraordinary behaviors. The jewel wasp, Nasonia vitripennis, harbors a heterochromatic, paternally transmitted B chromosome known as paternal sex ratio (PSR), which causes complete elimination of the sperm-contributed half of the genome during the first mitotic division of fertilized embryos. This genome elimination event may result from specific, previously observed alterations of the paternal chromatin. Due to the haplo-diploid reproduction of the wasp, genome elimination by PSR causes female-destined embryos to develop as haploid males that transmit PSR. PSR does not undergo self-elimination despite its presence with the paternal chromatin until the elimination event. Here we performed fluorescence microscopic analyses aimed at understanding this unexplained property. Our results show that PSR, like the rest of the genome, participates in the histone-to-protamine transition, arguing that PSR does not avoid this transition to escape self-elimination. In addition, PSR partially escapes the chromatin-altering activity of the intracellular bacterium, Wolbachia, demonstrating that this ability to evade chromatin alteration is not limited to PSR's own activity. Finally, we observed that the rDNA locus and other unidentified heterochromatic regions of the wasp's genome also seem to evade chromatin disruption by PSR, suggesting that PSR's genome-eliminating activity does not affect heterochromatin. Thus, PSR may target an aspect of euchromatin to cause genome elimination.
Collapse
Affiliation(s)
- Haena Lee
- W. M. Keck Science Department, Claremont McKenna, Pitzer and Scripps Colleges, Claremont, CA, 91711, USA
| | - Pooreum Seo
- W. M. Keck Science Department, Claremont McKenna, Pitzer and Scripps Colleges, Claremont, CA, 91711, USA
| | - Salina Teklay
- W. M. Keck Science Department, Claremont McKenna, Pitzer and Scripps Colleges, Claremont, CA, 91711, USA
| | - Emily Yuguchi
- W. M. Keck Science Department, Claremont McKenna, Pitzer and Scripps Colleges, Claremont, CA, 91711, USA
| | - Elena Dalla Benetta
- W. M. Keck Science Department, Claremont McKenna, Pitzer and Scripps Colleges, Claremont, CA, 91711, USA
- Division of Biological Sciences, Section of Cell and Developmental Biology, University of California, San Diego, La Jolla, CA, 92093, USA
| | - John H Werren
- Department of Biology, University of Rochester, Rochester, NY, 14627, USA
| | - Patrick M Ferree
- W. M. Keck Science Department, Claremont McKenna, Pitzer and Scripps Colleges, Claremont, CA, 91711, USA.
| |
Collapse
|
4
|
Pradhan S, Solomon R, Gangotra A, Yakubov GE, Willmott GR, Whitby CP, Hale TK, Williams MAK. Depletion of HP1α alters the mechanical properties of MCF7 nuclei. Biophys J 2021; 120:2631-2643. [PMID: 34087208 DOI: 10.1016/j.bpj.2021.05.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2020] [Revised: 05/11/2021] [Accepted: 05/14/2021] [Indexed: 11/27/2022] Open
Abstract
Within the nucleus of the eukaryotic cell, DNA is partitioned into domains of highly condensed, transcriptionally silent heterochromatin and less condensed, transcriptionally active euchromatin. Heterochromatin protein 1α (HP1α) is an architectural protein that establishes and maintains heterochromatin, ensuring genome fidelity and nuclear integrity. Although the mechanical effects of changes in the relative amount of euchromatin and heterochromatin brought about by inhibiting chromatin-modifying enzymes have been studied previously, here we measure how the material properties of the nuclei are modified after the knockdown of HP1α. These studies were inspired by the observation that poorly invasive MCF7 breast cancer cells become more invasive after knockdown of HP1α expression and that, indeed, in many solid tumors the loss of HP1α correlates with the onset of tumor cell invasion. Atomic force microscopy (AFM), optical tweezers (OT), and techniques based on micropipette aspiration (MA) were each used to characterize the mechanical properties of nuclei extracted from HP1α knockdown or matched control MCF7 cells. Using AFM or OT to locally indent nuclei, those extracted from MCF7 HP1α knockdown cells were found to have apparent Young's moduli that were significantly lower than nuclei from MCF7 control cells, consistent with previous studies that assert heterochromatin plays a major role in governing the mechanical response in such experiments. In contrast, results from pipette-based techniques in the spirit of MA, in which the whole nuclei were deformed and aspirated into a conical pipette, showed considerably less variation between HP1α knockdown and control, consistent with previous studies reporting that it is predominantly the lamins in the nuclear envelope that determine the mechanical response to large whole-cell deformations. The differences in chromatin organization observed by various microscopy techniques between the MCF7 control and HP1α knockdown nuclei correlate well with the results of our measured mechanical responses and our hypotheses regarding their origin.
Collapse
Affiliation(s)
- Susav Pradhan
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand; The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand
| | - Raoul Solomon
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand
| | - Ankita Gangotra
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand; Department of Physics, The University of Auckland, Auckland, New Zealand
| | - Gleb E Yakubov
- School of Chemical Engineering, The University of Queensland, Brisbane, Australia; School of Biosciences, Faculty of Science, University of Nottingham, Nottingham, United Kingdom
| | - Geoff R Willmott
- The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand; Department of Physics, The University of Auckland, Auckland, New Zealand; School of Chemical Sciences, The University of Auckland, Auckland, New Zealand
| | - Catherine P Whitby
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand; The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand
| | - Tracy K Hale
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand.
| | - Martin A K Williams
- School of Fundamental Sciences, Massey University, Palmerston North, New Zealand; The MacDiarmid Institute for Advanced Materials and Nanotechnology, Wellington, New Zealand.
| |
Collapse
|
5
|
Decato BE, Qu J, Ji X, Wagenblast E, Knott SRV, Hannon GJ, Smith AD. Characterization of universal features of partially methylated domains across tissues and species. Epigenetics Chromatin 2020; 13:39. [PMID: 33008446 PMCID: PMC7532633 DOI: 10.1186/s13072-020-00363-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Accepted: 09/23/2020] [Indexed: 12/12/2022] Open
Abstract
BACKGROUND Partially methylated domains (PMDs) are a hallmark of epigenomes in reproducible and specific biological contexts, including cancer cells, the placenta, and cultured cell lines. Existing methods for deciding whether PMDs exist in a sample, as well as their identification, are few, often tailored to specific biological questions, and require high coverage samples for accurate identification. RESULTS In this study, we outline a set of axioms that take a step towards a functional definition for PMDs, describe an improved method for comparable PMD detection across samples with substantially differing sequencing depths, and refine the decision criteria for whether a sample contains PMDs using a data-driven approach. Applying our method to 267 methylomes from 7 species, we corroborated recent results regarding the general association between replication timing and PMD state, and report identification of several reproducibly "escapee" genes within late-replicating domains that escape the reduced expression and hypomethylation of their immediate genomic neighborhood. We also explored the discordant PMD state of orthologous genes between human and mouse, and observed a directional association of PMD state with gene expression and local gene density. CONCLUSIONS Our improved method makes low sequencing depth, population-level studies of PMD variation possible and our results further refine the model of PMD formation as one where sequence context and regional epigenomic features both play a role in gradual genome-wide hypomethylation.
Collapse
Affiliation(s)
- Benjamin E. Decato
- Quantitative and Computational Biology Section, University of Southern California, Childs Way, Los Angeles, California USA
| | - Jianghan Qu
- Quantitative and Computational Biology Section, University of Southern California, Childs Way, Los Angeles, California USA
| | - Xiaojing Ji
- Quantitative and Computational Biology Section, University of Southern California, Childs Way, Los Angeles, California USA
| | - Elvin Wagenblast
- Watson School of Biological Sciences, Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724 USA
- Princess Margaret Cancer Centre, University Health Network, University of Toronto, Toronto, M5G 1L7 Canada
- Department of Molecular Genetics, University of Toronto, Toronto, M5G 1L7 Canada
| | - Simon R. V. Knott
- Watson School of Biological Sciences, Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724 USA
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE UK
- Center for Bioinformatics and Functional Genomics, Department of Biomedical Sciences, Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Los Angeles, CA 90048 USA
| | - Gregory J. Hannon
- Watson School of Biological Sciences, Howard Hughes Medical Institute, Cold Spring Harbor Laboratory, 1 Bungtown Road, Cold Spring Harbor, New York 11724 USA
- Cancer Research UK Cambridge Institute, University of Cambridge, Li Ka Shing Centre, Robinson Way, Cambridge, CB2 0RE UK
- New York Genome Center, 101 6th Avenue, New York, NY 10013 USA
| | - Andrew D. Smith
- Quantitative and Computational Biology Section, University of Southern California, Childs Way, Los Angeles, California USA
| |
Collapse
|
6
|
Tsurumi A, Li WX. Aging mechanisms-A perspective mostly from Drosophila. ADVANCED GENETICS (HOBOKEN, N.J.) 2020; 1:e10026. [PMID: 36619249 PMCID: PMC9744567 DOI: 10.1002/ggn2.10026] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 04/04/2020] [Accepted: 04/08/2020] [Indexed: 01/11/2023]
Abstract
A mechanistic understanding of the natural aging process, which is distinct from aging-related disease mechanisms, is essential for developing interventions to extend lifespan or healthspan. Here, we discuss current trends in aging research and address conceptual and experimental challenges in the field. We examine various molecular markers implicated in aging with an emphasis on the role of heterochromatin and epigenetic changes. Studies in model organisms have been advantageous in elucidating conserved genetic and epigenetic mechanisms and assessing interventions that affect aging. We highlight the use of Drosophila, which allows controlled studies for evaluating genetic and environmental contributors to aging conveniently. Finally, we propose the use of novel methodologies and future strategies using Drosophila in aging research.
Collapse
Affiliation(s)
- Amy Tsurumi
- Department of SurgeryMassachusetts General Hospital, and Harvard Medical SchoolBostonMassachusettsUSA,Department of Microbiology and ImmunologyHarvard Medical SchoolBostonMassachusettsUSA,Shriners Hospitals for Children‐Boston®BostonMassachusettsUSA
| | - Willis X. Li
- Department of MedicineUniversity of California at San DiegoLa JollaCaliforniaUSA
| |
Collapse
|
7
|
Dunlevy KL, Medvedeva V, Wilson JE, Hoque M, Pellegrin T, Maynard A, Kremp MM, Wasserman JS, Poleshko A, Katz RA. The PRR14 heterochromatin tether encodes modular domains that mediate and regulate nuclear lamina targeting. J Cell Sci 2020; 133:jcs240416. [PMID: 32317397 PMCID: PMC7272351 DOI: 10.1242/jcs.240416] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Accepted: 04/01/2020] [Indexed: 01/01/2023] Open
Abstract
A large fraction of epigenetically silent heterochromatin is anchored to the nuclear periphery via 'tethering proteins' that function to bridge heterochromatin and the nuclear membrane or nuclear lamina. We previously identified a human tethering protein, PRR14, that binds heterochromatin through an N-terminal domain, but the mechanism and regulation of nuclear lamina association remained to be investigated. Here we identify an evolutionarily conserved PRR14 nuclear lamina binding domain (LBD) that is both necessary and sufficient for positioning of PRR14 at the nuclear lamina. We show that PRR14 associates dynamically with the nuclear lamina, and provide evidence that such dynamics are regulated through phosphorylation and dephosphorylation of the LBD. Furthermore, we identify a PP2A phosphatase recognition motif within the evolutionarily conserved C-terminal Tantalus domain of PRR14. Disruption of this motif affects PRR14 localization to the nuclear lamina. The overall findings demonstrate a heterochromatin anchoring mechanism whereby the PRR14 tether simultaneously binds heterochromatin and the nuclear lamina through two separable modular domains. Our findings also describe an optimal PRR14 LBD fragment that could be used for efficient targeting of fusion proteins to the nuclear lamina.
Collapse
Affiliation(s)
- Kelly L Dunlevy
- Cancer Epigenetics Program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA
| | - Valentina Medvedeva
- Cancer Epigenetics Program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA
| | - Jade E Wilson
- Cancer Epigenetics Program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA
| | - Mohammed Hoque
- Cancer Epigenetics Program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA
| | - Trinity Pellegrin
- Cancer Epigenetics Program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA
| | - Adam Maynard
- Cancer Epigenetics Program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA
| | - Madison M Kremp
- Cancer Epigenetics Program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA
| | - Jason S Wasserman
- Cancer Epigenetics Program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA
| | - Andrey Poleshko
- Department of Cell and Developmental Biology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Richard A Katz
- Cancer Epigenetics Program, Fox Chase Cancer Center, Temple University Health System, Philadelphia, PA 19111, USA
| |
Collapse
|
8
|
Loss of an H3K9me anchor rescues laminopathy-linked changes in nuclear organization and muscle function in an Emery-Dreifuss muscular dystrophy model. Genes Dev 2020; 34:560-579. [PMID: 32139421 PMCID: PMC7111258 DOI: 10.1101/gad.332213.119] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 02/14/2020] [Indexed: 12/30/2022]
Abstract
In this study, Harr et al. use C. elegans to investigate the consequences of a missense mutation (Y45C) in lamin A (encoded by LMNA) found in the human Emery-Dreifuss muscular dystrophy (EDMD) syndrome. Using muscle-specific emerin Dam-ID and other in vivo approaches, the authors report that they were able to counteract the dominant muscle-specific defects provoked by LMNA mutation by the ablation of a lamin-associated H3K9me anchor, suggesting a novel therapeutic pathway for treating EDMD. Mutations in the nuclear structural protein lamin A produce rare, tissue-specific diseases called laminopathies. The introduction of a human Emery-Dreifuss muscular dystrophy (EDMD)-inducing mutation into the C. elegans lamin (LMN-Y59C), recapitulates many muscular dystrophy phenotypes, and correlates with hyper-sequestration of a heterochromatic array at the nuclear periphery in muscle cells. Using muscle-specific emerin Dam-ID in worms, we monitored the effects of the mutation on endogenous chromatin. An increased contact with the nuclear periphery along chromosome arms, and an enhanced release of chromosomal centers, coincided with the disease phenotypes of reduced locomotion and compromised sarcomere integrity. The coupling of the LMN-Y59C mutation with the ablation of CEC-4, a chromodomain protein that anchors H3K9-methylated chromatin at the nuclear envelope (NE), suppressed the muscle-associated disease phenotypes. Deletion of cec-4 also rescued LMN-Y59C-linked alterations in chromatin organization and some changes in transcription. Sequences that changed position in the LMN-Y59C mutant, are enriched for E2F (EFL-2)-binding sites, consistent with previous studies suggesting that altered Rb-E2F interaction with lamin A may contribute to muscle dysfunction. In summary, we were able to counteract the dominant muscle-specific defects provoked by LMNA mutation by the ablation of a lamin-associated H3K9me anchor, suggesting a novel therapeutic pathway for EDMD.
Collapse
|
9
|
Meli VS, Veerasubramanian PK, Atcha H, Reitz Z, Downing TL, Liu WF. Biophysical regulation of macrophages in health and disease. J Leukoc Biol 2019; 106:283-299. [PMID: 30861205 PMCID: PMC7001617 DOI: 10.1002/jlb.mr0318-126r] [Citation(s) in RCA: 67] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Macrophages perform critical functions for homeostasis and immune defense in tissues throughout the body. These innate immune cells are capable of recognizing and clearing dead cells and pathogens, and orchestrating inflammatory and healing processes that occur in response to injury. In addition, macrophages are involved in the progression of many inflammatory diseases including cardiovascular disease, fibrosis, and cancer. Although it has long been known that macrophages respond dynamically to biochemical signals in their microenvironment, the role of biophysical cues has only recently emerged. Furthermore, many diseases that involve macrophages are also characterized by changes to the tissue biophysical environment. This review will discuss current knowledge about the effects of biophysical cues including matrix stiffness, material topography, and applied mechanical forces, on macrophage behavior. We will also describe the role of molecules that are known to be important for mechanotransduction, including adhesion molecules, ion channels, as well as nuclear mediators such as transcription factors, scaffolding proteins, and epigenetic regulators. Together, this review will illustrate a developing role of biophysical cues in macrophage biology, and also speculate upon molecular targets that may potentially be exploited therapeutically to treat disease.
Collapse
Affiliation(s)
- Vijaykumar S. Meli
- Department of Biomedical Engineering, University of California Irvine, CA 92697
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California Irvine, CA 92697
| | - Praveen K. Veerasubramanian
- Department of Biomedical Engineering, University of California Irvine, CA 92697
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California Irvine, CA 92697
| | - Hamza Atcha
- Department of Biomedical Engineering, University of California Irvine, CA 92697
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California Irvine, CA 92697
| | - Zachary Reitz
- Department of Biomedical Engineering, University of California Irvine, CA 92697
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California Irvine, CA 92697
| | - Timothy L. Downing
- Department of Biomedical Engineering, University of California Irvine, CA 92697
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California Irvine, CA 92697
- Department of Microbiology and Molecular Genetics, University of California Irvine, CA 92697
| | - Wendy F. Liu
- Department of Biomedical Engineering, University of California Irvine, CA 92697
- The Edwards Lifesciences Center for Advanced Cardiovascular Technology, University of California Irvine, CA 92697
- Department of Chemical and Biomolecular Engineering, University of California Irvine, CA 92697
| |
Collapse
|
10
|
Ranade D, Pradhan R, Jayakrishnan M, Hegde S, Sengupta K. Lamin A/C and Emerin depletion impacts chromatin organization and dynamics in the interphase nucleus. BMC Mol Cell Biol 2019; 20:11. [PMID: 31117946 PMCID: PMC6532135 DOI: 10.1186/s12860-019-0192-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 04/16/2019] [Indexed: 12/26/2022] Open
Abstract
Background Nuclear lamins are type V intermediate filament proteins that maintain nuclear structure and function. Furthermore, Emerin - an interactor of Lamin A/C, facilitates crosstalk between the cytoskeleton and the nucleus as it also interacts with actin and Nuclear Myosin 1 (NM1). Results Here we show that the depletion of Lamin A/C or Emerin, alters the localization of the nuclear motor protein - Nuclear Myosin 1 (NM1) that manifests as an increase in NM1 foci in the nucleus and are rescued to basal levels upon the combined knockdown of Lamin A/C and Emerin. Furthermore, Lamin A/C-Emerin co-depletion destabilizes cytoskeletal organization as it increases actin stress fibers. This further impinges on nuclear organization, as it enhances chromatin mobility more toward the nuclear interior in Lamin A/C-Emerin co-depleted cells. This enhanced chromatin mobility was restored to basal levels either upon inhibition of Nuclear Myosin 1 (NM1) activity or actin depolymerization. In addition, the combined loss of Lamin A/C and Emerin alters the otherwise highly conserved spatial positions of chromosome territories. Furthermore, knockdown of Lamin A/C or Lamin A/C-Emerin combined, deregulates expression levels of a candidate subset of genes. Amongst these genes, both KLK10 (Chr.19, Lamina Associated Domain (LAD+)) and MADH2 (Chr.18, LAD-) were significantly repressed, while BCL2L12 (Chr.19, LAD-) is de-repressed. These genes differentially reposition with respect to the nuclear envelope. Conclusions Taken together, these studies underscore a remarkable interplay between Lamin A/C and Emerin in modulating cytoskeletal organization of actin and NM1 that impinges on chromatin dynamics and function in the interphase nucleus. Electronic supplementary material The online version of this article (10.1186/s12860-019-0192-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Devika Ranade
- Indian Institute of Science Education and Research (IISER)-Pune, Dr. Homi Bhabha Road, Biology, Room#B-216, 1st Floor, Main Building, Pashan, Pune, Maharashtra, 411008, India
| | - Roopali Pradhan
- Indian Institute of Science Education and Research (IISER)-Pune, Dr. Homi Bhabha Road, Biology, Room#B-216, 1st Floor, Main Building, Pashan, Pune, Maharashtra, 411008, India
| | - Muhunden Jayakrishnan
- Indian Institute of Science Education and Research (IISER)-Pune, Dr. Homi Bhabha Road, Biology, Room#B-216, 1st Floor, Main Building, Pashan, Pune, Maharashtra, 411008, India
| | - Sushmitha Hegde
- Indian Institute of Science Education and Research (IISER)-Pune, Dr. Homi Bhabha Road, Biology, Room#B-216, 1st Floor, Main Building, Pashan, Pune, Maharashtra, 411008, India
| | - Kundan Sengupta
- Indian Institute of Science Education and Research (IISER)-Pune, Dr. Homi Bhabha Road, Biology, Room#B-216, 1st Floor, Main Building, Pashan, Pune, Maharashtra, 411008, India.
| |
Collapse
|
11
|
Weinhouse C, Truong L, Meyer JN, Allard P. Caenorhabditis elegans as an emerging model system in environmental epigenetics. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2018; 59:560-575. [PMID: 30091255 PMCID: PMC6113102 DOI: 10.1002/em.22203] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/27/2017] [Revised: 04/13/2018] [Accepted: 04/19/2018] [Indexed: 05/19/2023]
Abstract
The roundworm Caenorhabitis elegans has been an established model organism for the study of genetics and developmental biology, including studies of transcriptional regulation, since the 1970s. This model organism has continued to be used as a classical model system as the field of transcriptional regulation has expanded to include scientific advances in epigenetics and chromatin biology. In the last several decades, C. elegans has emerged as a powerful model for environmental toxicology, particularly for the study of chemical genotoxicity. Here, we outline the utility and applicability of C. elegans as a powerful model organism for mechanistic studies of environmental influences on the epigenome. Our goal in this article is to inform the field of environmental epigenetics of the strengths and limitations of the well-established C. elegans model organism as an emerging model for medium-throughput, in vivo exploration of the role of exogenous chemical stimuli in transcriptional regulation, developmental epigenetic reprogramming, and epigenetic memory and inheritance. As the field of environmental epigenetics matures, and research begins to map mechanisms underlying observed associations, new toolkits and model systems, particularly manipulable, scalable in vivo systems that accurately model human transcriptional regulatory circuits, will provide an essential experimental bridge between in vitro biochemical experiments and mammalian model systems. Environ. Mol. Mutagen. 59:560-575, 2018. © 2018 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Caren Weinhouse
- Duke Global Health Institute, Duke University, Durham, North Carolina
- Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Lisa Truong
- UCLA Human Genetics and Genomic Analysis Training Program, University of California, Los Angeles; Los Angeles, California
| | - Joel N. Meyer
- Duke Global Health Institute, Duke University, Durham, North Carolina
- Nicholas School of the Environment, Duke University, Durham, North Carolina
| | - Patrick Allard
- Institute for Society and Genetics, University of California at Los Angeles, Los Angeles, California
| |
Collapse
|
12
|
Zhang Q, Tamashunas AC, Lele TP. A Direct Force Probe for Measuring Mechanical Integration Between the Nucleus and the Cytoskeleton. J Vis Exp 2018. [PMID: 30102282 DOI: 10.3791/58038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
The mechanical properties of the nucleus determine its response to mechanical forces generated in cells. Because the nucleus is molecularly continuous with the cytoskeleton, methods are needed to probe its mechanical behavior in adherent cells. Here, we discuss the direct force probe (DFP) as a tool to apply force directly to the nucleus in a living adherent cell. We attach a narrow micropipette to the nuclear surface with suction. The micropipette is translated away from the nucleus, which causes the nucleus to deform and translate. When the restoring force is equal to the suction force, the nucleus detaches and elastically relaxes. Because the suction pressure is precisely known, the force on the nuclear surface is known. This method has revealed that nano-scale forces are sufficient to deform and translate the nucleus in adherent cells, and identified cytoskeletal elements that enable the nucleus to resist forces. The DFP can be used to dissect the contributions of cellular and nuclear components to nuclear mechanical properties in living cells.
Collapse
Affiliation(s)
- Qiao Zhang
- Department of Chemical Engineering, University of Florida
| | | | - Tanmay P Lele
- Department of Chemical Engineering, University of Florida;
| |
Collapse
|
13
|
The three-dimensional organization of the genome in cellular senescence and age-associated diseases. Semin Cell Dev Biol 2018; 90:154-160. [PMID: 30031215 DOI: 10.1016/j.semcdb.2018.07.022] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2018] [Accepted: 07/17/2018] [Indexed: 01/18/2023]
Abstract
Recent advances in genomics and imaging technologies have increased our ability to interrogate the 3D conformation of chromosomes and to better understand principles of organization and dynamics, as well as how their alteration can lead to disease. In this review we describe how these technologies have shed new light into the role of the 3D organization of the genome in defining cellular states in aging and age-associated diseases. We compare the genomic organization in cellular senescence and cancer, discuss the role of the lamina in maintaining the structural and functional integrity of the genome, and we highlight the recent findings on how this organization breaks down in disease states.
Collapse
|
14
|
Pradhan R, Ranade D, Sengupta K. Emerin modulates spatial organization of chromosome territories in cells on softer matrices. Nucleic Acids Res 2018; 46:5561-5586. [PMID: 29684168 PMCID: PMC6009696 DOI: 10.1093/nar/gky288] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 04/04/2018] [Accepted: 04/06/2018] [Indexed: 02/06/2023] Open
Abstract
Cells perceive and relay external mechanical forces into the nucleus through the nuclear envelope. Here we examined the effect of lowering substrate stiffness as a paradigm to address the impact of altered mechanical forces on nuclear structure-function relationships. RNA sequencing of cells on softer matrices revealed significant transcriptional imbalances, predominantly in chromatin associated processes and transcriptional deregulation of human Chromosome 1. Furthermore, 3-Dimensional fluorescence in situ hybridization (3D-FISH) analyses showed a significant mislocalization of Chromosome 1 and 19 Territories (CT) into the nuclear interior, consistent with their transcriptional deregulation. However, CT18 with relatively lower transcriptional dysregulation, also mislocalized into the nuclear interior. Furthermore, nuclear Lamins that regulate chromosome positioning, were mislocalized into the nuclear interior in response to lowered matrix stiffness. Notably, Lamin B2 overexpression retained CT18 near the nuclear periphery in cells on softer matrices. While, cells on softer matrices also activated emerin phosphorylation at a novel Tyr99 residue, the inhibition of which in a phospho-deficient mutant (emerinY99F), selectively retained chromosome 18 and 19 but not chromosome 1 territories at their conserved nuclear locations. Taken together, emerin functions as a key mechanosensor, that modulates the spatial organization of chromosome territories in the interphase nucleus.
Collapse
Affiliation(s)
- Roopali Pradhan
- Biology, Main Building, First Floor, Room#B-216, Indian Institute of Science Education and Research (IISER), Pune, Dr Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India
| | - Devika Ranade
- Biology, Main Building, First Floor, Room#B-216, Indian Institute of Science Education and Research (IISER), Pune, Dr Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India
| | - Kundan Sengupta
- Biology, Main Building, First Floor, Room#B-216, Indian Institute of Science Education and Research (IISER), Pune, Dr Homi Bhabha Road, Pashan, Pune 411008, Maharashtra, India
| |
Collapse
|
15
|
Rapisarda V, Malashchuk I, Asamaowei IE, Poterlowicz K, Fessing MY, Sharov AA, Karakesisoglou I, Botchkarev VA, Mardaryev A. p63 Transcription Factor Regulates Nuclear Shape and Expression of Nuclear Envelope-Associated Genes in Epidermal Keratinocytes. J Invest Dermatol 2017; 137:2157-2167. [PMID: 28595999 PMCID: PMC5610935 DOI: 10.1016/j.jid.2017.05.013] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 04/20/2017] [Accepted: 05/01/2017] [Indexed: 01/07/2023]
Abstract
The maintenance of a proper nuclear architecture and three-dimensional organization of the genes, enhancer elements, and transcription machinery plays an essential role in tissue development and regeneration. Here we show that in the developing skin, epidermal progenitor cells of mice lacking p63 transcription factor display alterations in the nuclear shape accompanied by a marked decrease in expression of several nuclear envelope-associated components (Lamin B1, Lamin A/C, Sun1, Nesprin-3, Plectin) compared with controls. Furthermore, chromatin immunoprecipitation-quantitative PCR assay showed enrichment of p63 on Sun1, Syne3, and Plec promoters, suggesting them as p63 targets. Alterations in the nuclei shape and expression of nuclear envelope-associated proteins were accompanied by altered distribution patterns of the repressive histone marks trimethylation on lysine 27 of histone H3, trimethylation on lysine 9 of histone H3, and heterochromatin protein 1-alpha in p63-null keratinocytes. These changes were also accompanied by downregulation of the transcriptional activity and relocation of the keratinocyte-specific gene loci away from the sites of active transcription toward the heterochromatin-enriched repressive nuclear compartments in p63-null cells. These data demonstrate functional links between the nuclear envelope organization, chromatin architecture, and gene expression in keratinocytes and suggest nuclear envelope-associated genes as important targets mediating p63-regulated gene expression program in the epidermis.
Collapse
Key Words
- cc, chromocenter
- chip-qpcr, chromatin immunoprecipitation-quantitative pcr
- h3k9me3, trimethylation on lysine 9 of histone h3
- h3k27me3, trimethylation on lysine 27 of histone h3
- ktyi, keratin type i
- ktyii, keratin type ii
- pmk, primary mouse keratinocyte
- if, intermediate filament
- nm, nuclear membrane
- ne, nuclear envelope
- wt, wild-type
Collapse
Affiliation(s)
| | - Igor Malashchuk
- Centre for Skin Sciences, University of Bradford, Bradford, UK
| | | | | | | | - Andrey A Sharov
- Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts, USA
| | | | - Vladimir A Botchkarev
- Centre for Skin Sciences, University of Bradford, Bradford, UK; Department of Dermatology, Boston University School of Medicine, Boston, Massachusetts, USA.
| | | |
Collapse
|
16
|
Stephens AD, Banigan EJ, Adam SA, Goldman RD, Marko JF. Chromatin and lamin A determine two different mechanical response regimes of the cell nucleus. Mol Biol Cell 2017; 28:1984-1996. [PMID: 28057760 PMCID: PMC5541848 DOI: 10.1091/mbc.e16-09-0653] [Citation(s) in RCA: 277] [Impact Index Per Article: 39.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 11/04/2016] [Accepted: 12/29/2016] [Indexed: 02/02/2023] Open
Abstract
The cell nucleus must continually resist and respond to intercellular and intracellular mechanical forces to transduce mechanical signals and maintain proper genome organization and expression. Altered nuclear mechanics is associated with many human diseases, including heart disease, progeria, and cancer. Chromatin and nuclear envelope A-type lamin proteins are known to be key nuclear mechanical components perturbed in these diseases, but their distinct mechanical contributions are not known. Here we directly establish the separate roles of chromatin and lamin A/C and show that they determine two distinct mechanical regimes via micromanipulation of single isolated nuclei. Chromatin governs response to small extensions (<3 μm), and euchromatin/heterochromatin levels modulate the stiffness. In contrast, lamin A/C levels control nuclear strain stiffening at large extensions. These results can be understood through simulations of a polymeric shell and cross-linked polymer interior. Our results provide a framework for understanding the differential effects of chromatin and lamin A/C in cell nuclear mechanics and their alterations in disease.
Collapse
Affiliation(s)
- Andrew D Stephens
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208
| | - Edward J Banigan
- Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208
| | - Stephen A Adam
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - Robert D Goldman
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611
| | - John F Marko
- Department of Molecular Biosciences, Northwestern University, Evanston, IL 60208.,Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208
| |
Collapse
|
17
|
Feng W, Michaels SD. Accessing the Inaccessible: The Organization, Transcription, Replication, and Repair of Heterochromatin in Plants. Annu Rev Genet 2016; 49:439-59. [PMID: 26631514 DOI: 10.1146/annurev-genet-112414-055048] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Eukaryotic genomes often contain large quantities of potentially deleterious sequences, such as transposons. One strategy for mitigating this risk is to package such sequences into so-called constitutive heterochromatin, where the dense chromatin environment is thought to inhibit transcription by excluding transcription factors and RNA polymerase. This type of model makes it tempting to think of heterochromatin as an inert region that is isolated from the rest of the nucleus. Recent work on heterochromatin, however, reveals that it is a dynamic environment. Despite its dense packaging, heterochromatin must remain accessible for a host of processes, including DNA replication and repair, and, paradoxically, transcription. In plants, transcripts produced by specialized RNA polymerases are used to target regions of the genome for silencing via DNA methylation. Thus, the maintenance of heterochromatin requires a careful balancing act of access and exclusion, which is achieved through the action of a host of interrelated pathways.
Collapse
Affiliation(s)
- Wei Feng
- Carnegie Institution for Science, Department of Plant Biology, Stanford, California 94305;
| | - Scott D Michaels
- Department of Biology, Indiana University, Bloomington, Indiana 47405;
| |
Collapse
|
18
|
Chen H, Zheng X, Xiao D, Zheng Y. Age-associated de-repression of retrotransposons in the Drosophila fat body, its potential cause and consequence. Aging Cell 2016; 15:542-52. [PMID: 27072046 PMCID: PMC4854910 DOI: 10.1111/acel.12465] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/09/2016] [Indexed: 01/07/2023] Open
Abstract
Eukaryotic genomes contain transposable elements (TE) that can move into new locations upon activation. Since uncontrolled transposition of TEs, including the retrotransposons and DNA transposons, can lead to DNA breaks and genomic instability, multiple mechanisms, including heterochromatin‐mediated repression, have evolved to repress TE activation. Studies in model organisms have shown that TEs become activated upon aging as a result of age‐associated deregulation of heterochromatin. Considering that different organisms or cell types may undergo distinct heterochromatin changes upon aging, it is important to identify pathways that lead to TE activation in specific tissues and cell types. Through deep sequencing of isolated RNAs, we report an increased expression of many retrotransposons in the old Drosophila fat body, an organ equivalent to the mammalian liver and adipose tissue. This de‐repression correlates with an increased number of DNA damage foci and decreased level of Drosophila lamin‐B in the old fat body cells. Depletion of the Drosophila lamin‐B in the young or larval fat body results in a reduction of heterochromatin and a corresponding increase in retrotransposon expression and DNA damage. Further manipulations of lamin‐B and retrotransposon expression suggest a role of the nuclear lamina in maintaining the genome integrity of the Drosophila fat body by repressing retrotransposons.
Collapse
Affiliation(s)
- Haiyang Chen
- Key Laboratory of Gene Engineering of the Ministry of Education State Key Laboratory of Biocontrol School of Life Sciences Sun Yat‐sen University Guangzhou 510275 China
- Department of Embryology Carnegie Institution for Science Baltimore MD 21218 USA
| | - Xiaobin Zheng
- Department of Embryology Carnegie Institution for Science Baltimore MD 21218 USA
| | - Danqing Xiao
- Key Laboratory of Gene Engineering of the Ministry of Education State Key Laboratory of Biocontrol School of Life Sciences Sun Yat‐sen University Guangzhou 510275 China
| | - Yixian Zheng
- Department of Embryology Carnegie Institution for Science Baltimore MD 21218 USA
| |
Collapse
|
19
|
Abstract
The nuclear lamina, composed of lamins and numerous lamin-associated proteins, is required for mechanical stability, mechanosensing, chromatin organization, developmental gene regulation, mRNA transcription, DNA replication, nuclear assembly, and nuclear positioning. Mutations in lamins or lamin-binding proteins cause at least 18 distinct human diseases that affect specific tissues such as muscle, adipose, bone, nerve, or skin, and range from muscular dystrophies to lipodystrophy, peripheral neuropathy, or accelerated aging. Caenorhabditis elegans has unique advantages in studying lamin-binding proteins. These advantages include the low complexity of genes encoding lamin and lamin-binding proteins, advanced transgenic techniques, simple application of RNA interference, sophisticated genetic strategies, and a large collection of mutant lines. This chapter provides detailed and comprehensive protocols for the genetic and phenotypic analysis of lamin-binding proteins in C. elegans.
Collapse
Affiliation(s)
- Agnieszka Dobrzynska
- Andalusian Center for Developmental Biology, CSIC-Junta de Andalucia-Universidad Pablo de Olavide, Carretera de Utrera, Seville, Spain
| | - Peter Askjaer
- Andalusian Center for Developmental Biology, CSIC-Junta de Andalucia-Universidad Pablo de Olavide, Carretera de Utrera, Seville, Spain.
| | - Yosef Gruenbaum
- Department of Genetics, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel.
| |
Collapse
|
20
|
Outters P, Jaeger S, Zaarour N, Ferrier P. Long-Range Control of V(D)J Recombination & Allelic Exclusion: Modeling Views. Adv Immunol 2015; 128:363-413. [PMID: 26477371 DOI: 10.1016/bs.ai.2015.08.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Allelic exclusion of immunoglobulin (Ig) and T-cell receptor (TCR) genes ensures the development of B and T lymphocytes operating under the mode of clonal selection. This phenomenon associates asynchronous V(D)J recombination events at Ig or TCR alleles and inhibitory feedback control. Despite years of intense research, however, the mechanisms that sustain asymmetric choice in random Ig/TCR dual allele usage and the production of Ig/TCR monoallelic expressing B and T lymphocytes remain unclear and open for debate. In this chapter, we first recapitulate the biological evidence that almost from the start appeared to link V(D)J recombination and allelic exclusion. We review the theoretical models previously proposed to explain this connection. Finally, we introduce our own mathematical modeling views based on how the developmental dynamics of individual lymphoid cells combine to sustain allelic exclusion.
Collapse
Affiliation(s)
- Pernelle Outters
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université UM2, Inserm, U1104, CNRS UMR7280, 13288 Marseille, France
| | - Sébastien Jaeger
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université UM2, Inserm, U1104, CNRS UMR7280, 13288 Marseille, France
| | - Nancy Zaarour
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université UM2, Inserm, U1104, CNRS UMR7280, 13288 Marseille, France
| | - Pierre Ferrier
- Centre d'Immunologie de Marseille-Luminy, Aix-Marseille Université UM2, Inserm, U1104, CNRS UMR7280, 13288 Marseille, France.
| |
Collapse
|
21
|
Abstract
The modENCODE (Model Organism Encyclopedia of DNA Elements) Consortium aimed to map functional elements-including transcripts, chromatin marks, regulatory factor binding sites, and origins of DNA replication-in the model organisms Drosophila melanogaster and Caenorhabditis elegans. During its five-year span, the consortium conducted more than 2,000 genome-wide assays in developmentally staged animals, dissected tissues, and homogeneous cell lines. Analysis of these data sets provided foundational insights into genome, epigenome, and transcriptome structure and the evolutionary turnover of regulatory pathways. These studies facilitated a comparative analysis with similar data types produced by the ENCODE Consortium for human cells. Genome organization differs drastically in these distant species, and yet quantitative relationships among chromatin state, transcription, and cotranscriptional RNA processing are deeply conserved. Of the many biological discoveries of the modENCODE Consortium, we highlight insights that emerged from integrative studies. We focus on operational and scientific lessons that may aid future projects of similar scale or aims in other, emerging model systems.
Collapse
Affiliation(s)
- James B Brown
- Department of Statistics, University of California, Berkeley, California 94720;
| | | |
Collapse
|
22
|
Chen H, Zheng X, Zheng Y. Age-associated loss of lamin-B leads to systemic inflammation and gut hyperplasia. Cell 2015; 159:829-43. [PMID: 25417159 DOI: 10.1016/j.cell.2014.10.028] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 07/29/2014] [Accepted: 09/10/2014] [Indexed: 01/19/2023]
Abstract
Aging of immune organs, termed as immunosenescence, is suspected to promote systemic inflammation and age-associated disease. The cause of immunosenescence and how it promotes disease, however, has remained unclear. We report that the Drosophila fat body, a major immune organ, undergoes immunosenescence and mounts strong systemic inflammation that leads to deregulation of immune deficiency (IMD) signaling in the midgut of old animals. Inflamed old fat bodies secrete circulating peptidoglycan recognition proteins that repress IMD activity in the midgut, thereby promoting gut hyperplasia. Further, fat body immunosenecence is caused by age-associated lamin-B reduction specifically in fat body cells, which then contributes to heterochromatin loss and derepression of genes involved in immune responses. As lamin-associated heterochromatin domains are enriched for genes involved in immune response in both Drosophila and mammalian cells, our findings may provide insights into the cause and consequence of immunosenescence during mammalian aging. PAPERFLICK:
Collapse
Affiliation(s)
- Haiyang Chen
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
| | - Xiaobin Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA.
| |
Collapse
|
23
|
Jeong K, Kwon H, Lee J, Jang D, Pak Y. Insulin-response epigenetic activation of Egr-1 and JunB genes at the nuclear periphery by A-type lamin-associated pY19-Caveolin-2 in the inner nuclear membrane. Nucleic Acids Res 2015; 43:3114-27. [PMID: 25753664 PMCID: PMC4381080 DOI: 10.1093/nar/gkv181] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 02/20/2015] [Indexed: 11/15/2022] Open
Abstract
Insulin controls transcription to sustain its physiologic effects for the organism to adapt to environmental changes added to genetic predisposition. Nevertheless, insulin-induced transcriptional regulation by epigenetic factors and in defined nuclear territory remains elusive. Here we show that inner nuclear membrane (INM)-integrated caveolin-2 (Cav-2) regulates insulin-response epigenetic activation of Egr-1 and JunB genes at the nuclear periphery. INM-targeted pY19-Cav-2 in response to insulin associates specifically with the A-type lamin, disengages the repressed Egr-1 and JunB promoters from lamin A/C through disassembly of H3K9me3, and facilitates assembly of H3K9ac, H3K18ac and H3K27ac by recruitment of GCN5 and p300 and the subsequent enrichment of RNA polymerase II (Pol II) on the promoters at the nuclear periphery. Our findings show that Cav-2 is an epigenetic regulator of histone H3 modifications, and provide novel mechanisms of insulin-response epigenetic activation at the nuclear periphery.
Collapse
Affiliation(s)
- Kyuho Jeong
- Department of Biochemistry, Division of Applied Life Science (BK21 Plus Program), PMBBRC, Gyeongsang National University, Jinju 660-701, Korea
| | - Hayeong Kwon
- Department of Biochemistry, Division of Applied Life Science (BK21 Plus Program), PMBBRC, Gyeongsang National University, Jinju 660-701, Korea
| | - Jaewoong Lee
- Department of Biochemistry, Division of Applied Life Science (BK21 Plus Program), PMBBRC, Gyeongsang National University, Jinju 660-701, Korea
| | - Donghwan Jang
- Department of Biochemistry, Division of Applied Life Science (BK21 Plus Program), PMBBRC, Gyeongsang National University, Jinju 660-701, Korea
| | - Yunbae Pak
- Department of Biochemistry, Division of Applied Life Science (BK21 Plus Program), PMBBRC, Gyeongsang National University, Jinju 660-701, Korea
| |
Collapse
|
24
|
Furusawa T, Rochman M, Taher L, Dimitriadis EK, Nagashima K, Anderson S, Bustin M. Chromatin decompaction by the nucleosomal binding protein HMGN5 impairs nuclear sturdiness. Nat Commun 2015; 6:6138. [PMID: 25609380 PMCID: PMC4304400 DOI: 10.1038/ncomms7138] [Citation(s) in RCA: 97] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 12/15/2014] [Indexed: 12/19/2022] Open
Abstract
In most metazoan nuclei, heterochromatin is located at the nuclear periphery in contact with the nuclear lamina, which provides mechanical stability to the nucleus. We show that in cultured cells, chromatin de-compaction by the nucleosome binding protein HMGN5 decreases the sturdiness, elasticity, and rigidity of the nucleus. Mice overexpressing HMGN5, either globally or only in the heart, are normal at birth but develop hypertrophic heart with large cardiomyoctyes, deformed nuclei and disrupted lamina, and die of cardiac malfunction. Chromatin de-compaction is seen in cardiomyocytes of newborn mice but misshaped nuclei with disrupted lamina are seen only in adult cardiomyocytes, suggesting that loss of heterochromatin diminishes the ability of the nucleus to withstand the mechanical forces of the contracting heart. Thus, heterochromatin enhances the ability of the nuclear lamina to maintain the sturdiness and shape of the eukaryotic nucleus; a structural role for chromatin that is distinct from its genetic functions.
Collapse
Affiliation(s)
- Takashi Furusawa
- Protein Section, Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Mark Rochman
- Protein Section, Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Leila Taher
- Institute for Biostatistics and Informatics in Medicine and Ageing Research, University of Rostock, Rostock 18057, Germany
| | - Emilios K Dimitriadis
- Biomedical Engineering and Physical Science Shared Resource Program, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Kunio Nagashima
- Electron microscopy laboratory, Leidos Biomedical Research Inc., SAIC-Frederick Inc.,Frederick National Laboratory for Cancer Research, Frederick, Maryland 21701, USA
| | - Stasia Anderson
- Animal Core Facility, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| | - Michael Bustin
- Protein Section, Laboratory of Metabolism, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, USA
| |
Collapse
|
25
|
Cau P, Navarro C, Harhouri K, Roll P, Sigaudy S, Kaspi E, Perrin S, De Sandre-Giovannoli A, Lévy N. WITHDRAWN: Nuclear matrix, nuclear envelope and premature aging syndromes in a translational research perspective. Semin Cell Dev Biol 2014:S1084-9521(14)00058-5. [PMID: 24685615 DOI: 10.1016/j.semcdb.2014.03.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 03/03/2014] [Accepted: 03/09/2014] [Indexed: 10/25/2022]
Abstract
The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.semcdb.2014.03.022. The duplicate article has therefore been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at http://www.elsevier.com/locate/withdrawalpolicy.
Collapse
Affiliation(s)
- Pierre Cau
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); AP-HM, Service de Biologie Cellulaire, Hôpital La Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France(2).
| | - Claire Navarro
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1)
| | - Karim Harhouri
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1)
| | - Patrice Roll
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); AP-HM, Service de Biologie Cellulaire, Hôpital La Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France(2)
| | - Sabine Sigaudy
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); AP-HM, Département de Génétique Médicale, Hôpital d'enfants Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France(3)
| | - Elise Kaspi
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); AP-HM, Service de Biologie Cellulaire, Hôpital La Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France(2)
| | - Sophie Perrin
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1)
| | - Annachiara De Sandre-Giovannoli
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); AP-HM, Département de Génétique Médicale, Hôpital d'enfants Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France(3)
| | - Nicolas Lévy
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France(1); AP-HM, Département de Génétique Médicale, Hôpital d'enfants Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France(3).
| |
Collapse
|
26
|
Stroud MJ, Banerjee I, Veevers J, Chen J. Linker of nucleoskeleton and cytoskeleton complex proteins in cardiac structure, function, and disease. Circ Res 2014; 114:538-48. [PMID: 24481844 DOI: 10.1161/circresaha.114.301236] [Citation(s) in RCA: 70] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The linker of nucleoskeleton and cytoskeleton (LINC) complex, composed of proteins within the inner and the outer nuclear membranes, connects the nuclear lamina to the cytoskeleton. The importance of this complex has been highlighted by the discovery of mutations in genes encoding LINC complex proteins, which cause skeletal or cardiac myopathies. Herein, this review summarizes structure, function, and interactions of major components of the LINC complex, highlights how mutations in these proteins may lead to cardiac disease, and outlines future challenges in the field.
Collapse
Affiliation(s)
- Matthew J Stroud
- From the Department of Cardiology, University of California San Diego School of Medicine, La Jolla, CA
| | | | | | | |
Collapse
|
27
|
Cau P, Navarro C, Harhouri K, Roll P, Sigaudy S, Kaspi E, Perrin S, De Sandre-Giovannoli A, Lévy N. Nuclear matrix, nuclear envelope and premature aging syndromes in a translational research perspective. Semin Cell Dev Biol 2014; 29:125-47. [PMID: 24662892 DOI: 10.1016/j.semcdb.2014.03.021] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Lamin A-related progeroid syndromes are genetically determined, extremely rare and severe. In the past ten years, our knowledge and perspectives for these diseases has widely progressed, through the progressive dissection of their pathophysiological mechanisms leading to precocious and accelerated aging, from the genes mutations discovery until therapeutic trials in affected children. A-type lamins are major actors in several structural and functional activities at the nuclear periphery, as they are major components of the nuclear lamina. However, while this is usually poorly considered, they also play a key role within the rest of the nucleoplasm, whose defects are related to cell senescence. Although nuclear shape and nuclear envelope deformities are obvious and visible events, nuclear matrix disorganization and abnormal composition certainly represent the most important causes of cell defects with dramatic pathological consequences. Therefore, lamin-associated diseases should be better referred as laminopathies instead of envelopathies, this later being too restrictive, considering neither the key structural and functional roles of soluble lamins in the entire nucleoplasm, nor the nuclear matrix contribution to the pathophysiology of lamin-associated disorders and in particular in defective lamin A processing-associated aging diseases. Based on both our understanding of pathophysiological mechanisms and the biological and clinical consequences of progeria and related diseases, therapeutic trials have been conducted in patients and were terminated less than 10 years after the gene discovery, a quite fast issue for a genetic disease. Pharmacological drugs have been repurposed and used to decrease the toxicity of the accumulated, unprocessed and truncated prelaminA in progeria. To date, none of them may be considered as a cure for progeria and these clinical strategies were essentially designed toward reducing a subset of the most dramatic and morbid features associated to progeria. New therapeutic strategies under study, in particular targeting the protein expression pathway at the mRNA level, have shown a remarkable efficacy both in vitro in cells and in vivo in mice models. Strategies intending to clear the toxic accumulated proteins from the nucleus are also under evaluation. However, although exceedingly rare, improving our knowledge of genetic progeroid syndromes and searching for innovative and efficient therapies in these syndromes is of paramount importance as, even before they can be used to save lives, they may significantly (i) expand the affected childrens' lifespan and preserve their quality of life; (ii) improve our understanding of aging-related disorders and other more common diseases; and (iii) expand our fundamental knowledge of physiological aging and its links with major physiological processes such as those involved in oncogenesis.
Collapse
Affiliation(s)
- Pierre Cau
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; AP-HM, Service de Biologie Cellulaire, Hôpital La Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France.
| | - Claire Navarro
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Karim Harhouri
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Patrice Roll
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; AP-HM, Service de Biologie Cellulaire, Hôpital La Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France
| | - Sabine Sigaudy
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; AP-HM, Département de Génétique Médicale, Hôpital d'enfants Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France
| | - Elise Kaspi
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; AP-HM, Service de Biologie Cellulaire, Hôpital La Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France
| | - Sophie Perrin
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France
| | - Annachiara De Sandre-Giovannoli
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; AP-HM, Département de Génétique Médicale, Hôpital d'enfants Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France
| | - Nicolas Lévy
- Aix-Marseille Université, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; INSERM, UMR_S 910, Génétique Médicale et Génomique Fonctionnelle, Faculté de Médecine, 27 Bd Jean Moulin, 13385 Marseille Cedex 5, France; AP-HM, Département de Génétique Médicale, Hôpital d'enfants Timone, 264 Rue Saint Pierre, 13385 Marseille Cedex 5, France.
| |
Collapse
|
28
|
Abstract
A conserved organizational feature of eukaryotic nuclei is the peripheral heterochromatin compartment, which provides a protected area for epigenetically silent genes and gene-poor DNA. In metazoan cells this compartment is associated with the nuclear lamina, the protein meshwork at the inner edge of the nucleus. Heterochromatin-nuclear lamina interactions promote epigenetic gene silencing, which may drive many normal and diseased biological processes. We recently obtained evidence that a previously unstudied human protein, PRR14, participates in the tethering of heterochromatin to the inner nuclear periphery. PRR14 associates with the nuclear lamina and attaches to heterochromatin through its binding partner, heterochromatin protein 1 (HP1). After disassembly early in mitosis, PRR14 reassembles in two steps, first binding to anaphase chromosomes through HP1, followed by association with the nuclear lamina in telophase. PRR14 may thereby play a role in specifying HP1-bound heterochromatin for reattachment to the nuclear lamina at mitotic exit. Here we review the relevant literature, summarize our initial work, and provide additional comments and findings.
Collapse
Affiliation(s)
- Andrey Poleshko
- Fox Chase Cancer Center; Institute for Cancer Research; Philadelphia, PA USA
| | - Richard A Katz
- Fox Chase Cancer Center; Institute for Cancer Research; Philadelphia, PA USA
| |
Collapse
|
29
|
The nuclear lamina regulates germline stem cell niche organization via modulation of EGFR signaling. Cell Stem Cell 2014; 13:73-86. [PMID: 23827710 DOI: 10.1016/j.stem.2013.05.003] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Revised: 03/24/2013] [Accepted: 05/06/2013] [Indexed: 02/08/2023]
Abstract
Stem cell niche interactions have been studied extensively with regard to cell polarity and extracellular signaling. Less is known about the way in which signals and polarity cues integrate with intracellular structures to ensure appropriate niche organization and function. Here, we report that nuclear lamins function in the cyst stem cells (CySCs) of Drosophila testes to control the interaction of CySCs with the hub. This interaction is important for regulation of CySC differentiation and organization of the niche that supports the germline stem cells (GSCs). Lamin promotes nuclear retention of phosphorylated ERK in the CySC lineage by regulating the distribution of specific nucleoporins within the nuclear pores. Lamin-regulated nuclear epidermal growth factor (EGF) receptor signaling in the CySC lineage is essential for proliferation and differentiation of the GSCs and the transient amplifying germ cells. Thus, we have uncovered a role for the nuclear lamina in the integration of EGF signaling to regulate stem cell niche function.
Collapse
|
30
|
Lyakhovetsky R, Gruenbaum Y. Studying lamins in invertebrate models. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2014; 773:245-62. [PMID: 24563351 DOI: 10.1007/978-1-4899-8032-8_11] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Lamins are nuclear intermediate filament proteins that are conserved in all multicellular animals. Proteins that resemble lamins are also found in unicellular organisms and in plants. Lamins form a proteinaceous meshwork that outlines the nucleoplasmic side of the inner nuclear membrane, while a small fraction of lamin molecules is also present in the nucleoplasm. They provide structural support for the nucleus and help regulate many other nuclear activities. Much of our knowledge on the function of nuclear lamins and their associated proteins comes from studies in invertebrate organisms and specifically in the nematode Caenorhabditis elegans and the fruit fly Drosophila melanogaster. The simpler lamin system and the powerful genetic tools offered by these model organisms greatly promote such studies. Here we provide an overview of recent advances in the biology of invertebrate nuclear lamins, with special emphasis on their assembly, cellular functions and as models for studying the molecular basis underlying the pathology of human heritable diseases caused by mutations in lamins A/C.
Collapse
Affiliation(s)
- Roman Lyakhovetsky
- Department of Genetics, The Institute of Life Sciences, The Hebrew University of Jerusalem, Givat Ram, Jerusalem, 91904, Israel
| | | |
Collapse
|
31
|
Lindenboim L, Sasson T, Worman HJ, Borner C, Stein R. Cellular stress induces Bax-regulated nuclear bubble budding and rupture followed by nuclear protein release. Nucleus 2014; 5:527-41. [PMID: 25482068 PMCID: PMC4615202 DOI: 10.4161/19491034.2014.970105] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Revised: 07/31/2014] [Accepted: 09/15/2014] [Indexed: 11/19/2022] Open
Abstract
Cellular stress triggers many pathways including nuclear protein redistribution. We previously discovered that this process is regulated by Bax but the underlying mechanism has not yet been studied. Here we define this mechanism by showing that apoptotic stimuli cause Bax-regulated disturbances in lamin A/C and nuclear envelope (NE)-associated proteins which results in the generation and subsequent rupture of nuclear protein-containing bubbles. The bubbles do not contain DNA and are encapsulated by impaired nuclear pore-depleted NE. Stress-induced generation and rupture of nuclear bubbles ultimately leads to the discharge of nuclear proteins into the cytoplasm. This process precedes morphological changes of apoptosis and occurs independently of caspases. Rescue experiments revealed that this Bax effect is non-canonical, i.e. it requires the BH3 domain and α-helices 5 and 6 but it is not inhibited by Bcl(-)xL. Targeting Bax to the NE by the Klarsicht/ANC-1/Syne-1 homology (KASH) domain effectively triggers the generation and rupture of nuclear bubbles. Overall, our findings provide evidence for a novel stress-response, which is regulated by a non-canonical action of Bax on the NE.
Collapse
Key Words
- Bax
- Bax/Bak, Bax and Bak
- DKO, double knockout
- INM, inner nuclear membrane
- KASH, Klarsicht: ANC-1, Syne homology
- LAP, lamina-associated polypeptide
- LINC, links nucleoskeleton and cytoskeleton
- MEFs, mouse embryonic fibroblasts
- MOMP, mitochondrial outer membrane permeabilization
- NE, nuclear envelope
- NPCs, nuclear pore complexes
- NPM, nucleophosmin
- NPR, nuclear protein redistribution
- ONM, outer nuclear membrane
- PI, propidium iodide
- Q-VD-OPH, quinoline-Val-Asp(OMe)-CH2-OPH.
- SIGRUNB, stress-induced generation and rupture of nuclear bubbles
- apoptosis
- lamin
- nuclear envelope
- nucleus
Collapse
Affiliation(s)
- Liora Lindenboim
- Department of Neurobiology; George S. Wise Faculty of Life Sciences; Tel Aviv University; Ramat Aviv, Israel
| | - Tiki Sasson
- Department of Neurobiology; George S. Wise Faculty of Life Sciences; Tel Aviv University; Ramat Aviv, Israel
| | - Howard J Worman
- Department of Medicine and Department of Pathology and Cell Biology; College of Physicians and Surgeons; Columbia University; New York, NY, USA
| | - Christoph Borner
- Institute of Molecular Medicine and Cell Research; Albert Ludwigs University Freiburg; Freiburg, Germany
- Spemann Graduate School of Biology and Medicine (SGBM); Albert Ludwigs University Freiburg; Freiburg, Germany
- Excellence Cluster, Centre for Biological Signaling Studies (BIOSS); Albert Ludwigs University Freiburg; Freiburg, Germany
| | - Reuven Stein
- Department of Neurobiology; George S. Wise Faculty of Life Sciences; Tel Aviv University; Ramat Aviv, Israel
| |
Collapse
|
32
|
Prokocimer M, Barkan R, Gruenbaum Y. Hutchinson-Gilford progeria syndrome through the lens of transcription. Aging Cell 2013; 12:533-43. [PMID: 23496208 DOI: 10.1111/acel.12070] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/06/2013] [Indexed: 12/14/2022] Open
Abstract
Lamins are nuclear intermediate filaments. In addition to their structural roles, they are implicated in basic nuclear functions such as chromatin organization, DNA replication, transcription, DNA repair, and cell-cycle progression. Mutations in human LMNA gene cause several diseases termed laminopathies. One of the laminopathic diseases is Hutchinson-Gilford progeria syndrome (HGPS), which is caused by a spontaneous mutation and characterized by premature aging. HGPS phenotypes share certain similarities with several apparently comparable medical conditions, such as aging and atherosclerosis, with the conspicuous absence of neuronal degeneration and cancer rarity during the short lifespan of the patients. Cell lines from HGPS patients are characterized by multiple nuclear defects, which include abnormal morphology, altered histone modification patterns, and increased DNA damage. These cell lines provide insight into the molecular pathways including senescence that require lamins A and B1. Here, we review recent data on HGPS phenotypes through the lens of transcriptional deregulation caused by lack of functional lamin A, progerin accumulation, and lamin B1 silencing.
Collapse
Affiliation(s)
- Miron Prokocimer
- Department of Genetics, Institute of Life Sciences, Hebrew University of Jerusalem, 91904, Jerusalem, Israel
| | | | | |
Collapse
|
33
|
Imbalzano AN, Imbalzano KM, Nickerson JA. BRG1, a SWI/SNF chromatin remodeling enzyme ATPase, is required for maintenance of nuclear shape and integrity. Commun Integr Biol 2013; 6:e25153. [PMID: 24228137 PMCID: PMC3821668 DOI: 10.4161/cib.25153] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2013] [Accepted: 05/23/2013] [Indexed: 01/11/2023] Open
Abstract
We recently reported that reducing the levels of BRG1, the catalytic subunit of mammalian SWI/SNF chromatin remodeling enzymes, induces alterations in nuclear shape in a breast epithelial cell line. Immunostaining the BRG1 knockdown cells with nuclear lamina antibodies revealed a significantly increased frequency of grooves, or invaginations, in the nuclei. Disruption of each of the major cytoplasmic filament systems (actin, tubulin and cytokeratins) had no impact on the BRG1-dependent changes in nuclear shape, indicating that the observed changes in nuclear morphology are unlikely to be a result of alterations in the integrity of the nuclear-cytoplamic contacts in the cell. We propose that the BRG1-dependent nuclear shape changes reflect a role for the chromatin remodeling enzyme in maintaining the structural integrity of the nucleus via global regulation of chromatin structure and dynamics within the nucleus.
Collapse
Affiliation(s)
- Anthony N Imbalzano
- Department of Cell and Developmental Biology; University of Massachusetts Medical School; Worcester, MA USA
| | | | | |
Collapse
|
34
|
Díaz-Castillo C. Females and males contribute in opposite ways to the evolution of gene order in Drosophila. PLoS One 2013; 8:e64491. [PMID: 23696898 PMCID: PMC3655977 DOI: 10.1371/journal.pone.0064491] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 04/16/2013] [Indexed: 11/19/2022] Open
Abstract
An intriguing association between the spatial layout of chromosomes within nuclei and the evolution of chromosome gene order was recently uncovered. Chromosome regions with conserved gene order in the Drosophila genus are larger if they interact with the inner side of the nuclear envelope in D. melanogaster somatic cells. This observation opens a new door to understand the evolution of chromosomes in the light of the dynamics of the spatial layout of chromosomes and the way double-strand breaks are repaired in D. melanogaster germ lines. Chromosome regions at the nuclear periphery in somatic cell nuclei relocate to more internal locations of male germ line cell nuclei, which might prefer a gene order-preserving mechanism to repair double-strand breaks. Conversely, chromosome regions at the nuclear periphery in somatic cells keep their location in female germ line cell nuclei, which might be inaccessible for cellular machinery that causes gene order-disrupting chromosome rearrangements. Thus, the gene order stability for genome regions at the periphery of somatic cell nuclei might result from the active repair of double-strand breaks using conservative mechanisms in male germ line cells, and the passive inaccessibility for gene order-disrupting factors at the periphery of nuclei of female germ line cells. In the present article, I find evidence consistent with a DNA break repair-based differential contribution of both D. melanogaster germ lines to the stability/disruption of gene order. The importance of germ line differences for the layout of chromosomes and DNA break repair strategies with regard to other genomic patterns is briefly discussed.
Collapse
|
35
|
Pathak RU, Mamillapalli A, Rangaraj N, Kumar RP, Vasanthi D, Mishra K, Mishra RK. AAGAG repeat RNA is an essential component of nuclear matrix in Drosophila. RNA Biol 2013; 10:564-71. [PMID: 23588056 DOI: 10.4161/rna.24326] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Eukaryotic nucleus is functionally as well as spatially compartmentalized and maintains dynamic organization of sub-nuclear bodies. This organization is supported by a non-chromatin nuclear structure called the nuclear matrix. Although the precise molecular composition and ultra-structure of the nuclear matrix is not known, proteins and RNA molecules are its major components and several nuclear matrix proteins have been identified. However, the nature of its RNA component is unknown. Here we show that in Drosophila melanogaster, transcripts from AAGAG repeats of several hundred nucleotide in length are critical constituents of the nuclear matrix. While both the strands of this repeat are transcribed and are nuclear matrix associated, the polypurine strand is predominantly detected in situ. We also show that AAGAG RNA is essential for viability. Our results reveal the molecular identity of a critical RNA component of the nuclear architecture and point to one of the utilities of the repetitive part of the genome that has accumulated in higher eukaryotes.
Collapse
Affiliation(s)
- Rashmi U Pathak
- Centre for Cellular and Molecular Biology, Council of Scientific and Industrial Research, Hyderabad, India
| | | | | | | | | | | | | |
Collapse
|
36
|
Imbalzano KM, Cohet N, Wu Q, Underwood JM, Imbalzano AN, Nickerson JA. Nuclear shape changes are induced by knockdown of the SWI/SNF ATPase BRG1 and are independent of cytoskeletal connections. PLoS One 2013; 8:e55628. [PMID: 23405182 PMCID: PMC3566038 DOI: 10.1371/journal.pone.0055628] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Accepted: 01/02/2013] [Indexed: 11/24/2022] Open
Abstract
Changes in nuclear morphology occur during normal development and have been observed during the progression of several diseases. The shape of a nucleus is governed by the balance of forces exerted by nuclear-cytoskeletal contacts and internal forces created by the structure of the chromatin and nuclear envelope. However, factors that regulate the balance of these forces and determine nuclear shape are poorly understood. The SWI/SNF chromatin remodeling enzyme ATPase, BRG1, has been shown to contribute to the regulation of overall cell size and shape. Here we document that immortalized mammary epithelial cells show BRG1-dependent nuclear shape changes. Specifically, knockdown of BRG1 induced grooves in the nuclear periphery that could be documented by cytological and ultrastructural methods. To test the hypothesis that the observed changes in nuclear morphology resulted from altered tension exerted by the cytoskeleton, we disrupted the major cytoskeletal networks and quantified the frequency of BRG1-dependent changes in nuclear morphology. The results demonstrated that disruption of cytoskeletal networks did not change the frequency of BRG1-induced nuclear shape changes. These findings suggest that BRG1 mediates control of nuclear shape by internal nuclear mechanisms that likely control chromatin dynamics.
Collapse
Affiliation(s)
- Karen M Imbalzano
- Department of Cell and Developmental Biology, University of Massachusetts Medical School, Worcester, Massachusetts, United States of America
| | | | | | | | | | | |
Collapse
|
37
|
Affiliation(s)
- Chin Yee Ho
- Cornell University, Weill Institute for Cell and Molecular Biology, Department of Biomedical Engineering, Ithaca, NY 14853, USA
| | | |
Collapse
|
38
|
Abstract
The fifth U.K. meeting on nuclear envelope disease and chromatin brought together international experts from across the field of nuclear envelope biology to discuss the advancements in a class of tissue-specific degenerative diseases called the laminopathies. Clinically, these range from relatively mild fat-wasting disorders to the severe premature aging condition known as Hutchinson-Gilford progeria syndrome. Since the first association of the nuclear envelope with human inherited disease in 1994, there has been an exponential increase in an unexpected variety of functions associated with nuclear envelope proteins, ranging from mechanical support and nucleocytoskeletal connections to regulation of chromatin organization and gene expression. This Biochemical Society Focused Meeting reinforced the functional complexity of nuclear-associated diseases, revealed new avenues to be investigated and highlighted the signalling pathways suitable as therapeutic targets.
Collapse
|