1
|
Bruštíková K, Ryabchenko B, Žáčková S, Šroller V, Forstová J, Horníková L. Mouse polyomavirus infection induces lamin reorganisation. FEBS J 2024. [PMID: 39288210 DOI: 10.1111/febs.17275] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2024] [Revised: 07/02/2024] [Accepted: 09/06/2024] [Indexed: 09/19/2024]
Abstract
The nuclear lamina is a dense network of intermediate filaments beneath the inner nuclear membrane. Composed of A-type lamins (lamin A/C) and B-type lamins (lamins B1 and B2), the nuclear lamina provides a scaffold for the nuclear envelope and chromatin, thereby maintaining the structural integrity of the nucleus. A-type lamins are also found inside the nucleus where they interact with chromatin and participate in gene regulation. Viruses replicating in the cell nucleus have to overcome the nuclear envelope during the initial phase of infection and during the nuclear egress of viral progeny. Here, we focused on the role of lamins in the replication cycle of a dsDNA virus, mouse polyomavirus. We detected accumulation of the major capsid protein VP1 at the nuclear periphery, defects in nuclear lamina staining and different lamin A/C phosphorylation patterns in the late phase of mouse polyomavirus infection, but the nuclear envelope remained intact. An absence of lamin A/C did not affect the formation of replication complexes but did slow virus propagation. Based on our findings, we propose that the nuclear lamina is a scaffold for replication complex formation and that lamin A/C has a crucial role in the early phases of infection with mouse polyomavirus.
Collapse
Affiliation(s)
- Kateřina Bruštíková
- Department of Genetics and Microbiology, BIOCEV, Faculty of Science, Charles University, Prague, Czech Republic
| | - Boris Ryabchenko
- Department of Genetics and Microbiology, BIOCEV, Faculty of Science, Charles University, Prague, Czech Republic
| | - Sandra Žáčková
- Department of Genetics and Microbiology, BIOCEV, Faculty of Science, Charles University, Prague, Czech Republic
| | - Vojtěch Šroller
- Department of Genetics and Microbiology, BIOCEV, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jitka Forstová
- Department of Genetics and Microbiology, BIOCEV, Faculty of Science, Charles University, Prague, Czech Republic
| | - Lenka Horníková
- Department of Genetics and Microbiology, BIOCEV, Faculty of Science, Charles University, Prague, Czech Republic
| |
Collapse
|
2
|
Akinpelu A, Akinsipe T, Avila LA, Arnold RD, Mistriotis P. The impact of tumor microenvironment: unraveling the role of physical cues in breast cancer progression. Cancer Metastasis Rev 2024; 43:823-844. [PMID: 38238542 PMCID: PMC11156564 DOI: 10.1007/s10555-024-10166-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Accepted: 01/02/2024] [Indexed: 01/30/2024]
Abstract
Metastasis accounts for the vast majority of breast cancer-related fatalities. Although the contribution of genetic and epigenetic modifications to breast cancer progression has been widely acknowledged, emerging evidence underscores the pivotal role of physical stimuli in driving breast cancer metastasis. In this review, we summarize the changes in the mechanics of the breast cancer microenvironment and describe the various forces that impact migrating and circulating tumor cells throughout the metastatic process. We also discuss the mechanosensing and mechanotransducing molecules responsible for promoting the malignant phenotype in breast cancer cells. Gaining a comprehensive understanding of the mechanobiology of breast cancer carries substantial potential to propel progress in prognosis, diagnosis, and patient treatment.
Collapse
Affiliation(s)
- Ayuba Akinpelu
- Department of Chemical Engineering, Samuel Ginn College of Engineering, Auburn University, Auburn, AL, 36849, USA
| | - Tosin Akinsipe
- Department of Biological Sciences, College of Science and Mathematics, Auburn University, Auburn, AL, 36849, USA
| | - L Adriana Avila
- Department of Biological Sciences, College of Science and Mathematics, Auburn University, Auburn, AL, 36849, USA
| | - Robert D Arnold
- Department of Drug Discovery and Development, Harrison College of Pharmacy, Auburn University, Auburn, AL, 36849, USA
| | - Panagiotis Mistriotis
- Department of Chemical Engineering, Samuel Ginn College of Engineering, Auburn University, Auburn, AL, 36849, USA.
| |
Collapse
|
3
|
Pennarun G, Picotto J, Bertrand P. Close Ties between the Nuclear Envelope and Mammalian Telomeres: Give Me Shelter. Genes (Basel) 2023; 14:genes14040775. [PMID: 37107534 PMCID: PMC10137478 DOI: 10.3390/genes14040775] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2023] [Revised: 03/18/2023] [Accepted: 03/20/2023] [Indexed: 04/29/2023] Open
Abstract
The nuclear envelope (NE) in eukaryotic cells is essential to provide a protective compartment for the genome. Beside its role in connecting the nucleus with the cytoplasm, the NE has numerous important functions including chromatin organization, DNA replication and repair. NE alterations have been linked to different human diseases, such as laminopathies, and are a hallmark of cancer cells. Telomeres, the ends of eukaryotic chromosomes, are crucial for preserving genome stability. Their maintenance involves specific telomeric proteins, repair proteins and several additional factors, including NE proteins. Links between telomere maintenance and the NE have been well established in yeast, in which telomere tethering to the NE is critical for their preservation and beyond. For a long time, in mammalian cells, except during meiosis, telomeres were thought to be randomly localized throughout the nucleus, but recent advances have uncovered close ties between mammalian telomeres and the NE that play important roles for maintaining genome integrity. In this review, we will summarize these connections, with a special focus on telomere dynamics and the nuclear lamina, one of the main NE components, and discuss the evolutionary conservation of these mechanisms.
Collapse
Affiliation(s)
- Gaëlle Pennarun
- Université Paris Cité, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
- Université Paris-Saclay, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
| | - Julien Picotto
- Université Paris Cité, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
- Université Paris-Saclay, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
| | - Pascale Bertrand
- Université Paris Cité, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
- Université Paris-Saclay, INSERM, CEA, Stabilité Génétique Cellules Souches et Radiations, LREV/iRCM/IBFJ, F-92260 Fontenay-aux-Roses, France
| |
Collapse
|
4
|
Di Tomaso MV, Vázquez Alberdi L, Olsson D, Cancela S, Fernández A, Rosillo JC, Reyes Ábalos AL, Álvarez Zabaleta M, Calero M, Kun A. Colocalization Analysis of Peripheral Myelin Protein-22 and Lamin-B1 in the Schwann Cell Nuclei of Wt and TrJ Mice. Biomolecules 2022; 12:456. [PMID: 35327648 PMCID: PMC8946543 DOI: 10.3390/biom12030456] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 03/05/2022] [Accepted: 03/12/2022] [Indexed: 12/19/2022] Open
Abstract
Myelination of the peripheral nervous system requires Schwann cells (SC) differentiation into the myelinating phenotype. The peripheral myelin protein-22 (PMP22) is an integral membrane glycoprotein, expressed in SC. It was initially described as a growth arrest-specific (gas3) gene product, up-regulated by serum starvation. PMP22 mutations were pathognomonic for human hereditary peripheral neuropathies, including the Charcot-Marie-Tooth disease (CMT). Trembler-J (TrJ) is a heterozygous mouse model carrying the same pmp22 point mutation as a CMT1E variant. Mutations in lamina genes have been related to a type of peripheral (CMT2B1) or central (autosomal dominant leukodystrophy) neuropathy. We explore the presence of PMP22 and Lamin B1 in Wt and TrJ SC nuclei of sciatic nerves and the colocalization of PMP22 concerning the silent heterochromatin (HC: DAPI-dark counterstaining), the transcriptionally active euchromatin (EC), and the nuclear lamina (H3K4m3 and Lamin B1 immunostaining, respectively). The results revealed that the number of TrJ SC nuclei in sciatic nerves was greater, and the SC volumes were smaller than those of Wt. The myelin protein PMP22 and Lamin B1 were detected in Wt and TrJ SC nuclei and predominantly in peripheral nuclear regions. The level of PMP22 was higher, and those of Lamin B1 lower in TrJ than in Wt mice. The level of PMP22 was higher, and those of Lamin B1 lower in TrJ than in Wt mice. PMP22 colocalized more with Lamin B1 and with the transcriptionally competent EC, than the silent HC with differences between Wt and TrJ genotypes. The results are discussed regarding the probable nuclear role of PMP22 and the relationship with TrJ neuropathy.
Collapse
Affiliation(s)
- María Vittoria Di Tomaso
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (D.O.); (S.C.); (A.L.R.Á.); (M.Á.Z.)
| | - Lucía Vázquez Alberdi
- Laboratorio de Biología Celular del Sistema Nervioso Periférico, Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay;
| | - Daniela Olsson
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (D.O.); (S.C.); (A.L.R.Á.); (M.Á.Z.)
| | - Saira Cancela
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (D.O.); (S.C.); (A.L.R.Á.); (M.Á.Z.)
| | - Anabel Fernández
- Laboratorio de Neurobiología Comparada, Departamento de Neurociencias Integrativas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (A.F.); (J.C.R.)
| | - Juan Carlos Rosillo
- Laboratorio de Neurobiología Comparada, Departamento de Neurociencias Integrativas, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (A.F.); (J.C.R.)
| | - Ana Laura Reyes Ábalos
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (D.O.); (S.C.); (A.L.R.Á.); (M.Á.Z.)
- Laboratorio de Neurociencias, Facultad de Ciencias, Universidad de la República, Montevideo 11400, Uruguay
| | - Magdalena Álvarez Zabaleta
- Departamento de Genética, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay; (D.O.); (S.C.); (A.L.R.Á.); (M.Á.Z.)
| | - Miguel Calero
- Departamento de Histología y Embriología, Facultad de Medicina, Universidad de la República, Montevideo 11800, Uruguay
- Unidad de Microscopía Electrónica de Barrido, Universidad de la República, Montevideo 11400, Uruguay
| | - Alejandra Kun
- Laboratorio de Biología Celular del Sistema Nervioso Periférico, Departamento de Proteínas y Ácidos Nucleicos, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo 11600, Uruguay;
- Instituto de Salud Carlos III, Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CIBERNED), Unidad de Encefalopatías Espongiformes (UFIEC), 28029 Madrid, Spain;
| |
Collapse
|
5
|
Scaling concepts in 'omics: Nuclear lamin-B scales with tumor growth and often predicts poor prognosis, unlike fibrosis. Proc Natl Acad Sci U S A 2021; 118:2112940118. [PMID: 34810266 DOI: 10.1073/pnas.2112940118] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/29/2021] [Indexed: 12/28/2022] Open
Abstract
Physicochemical principles such as stoichiometry and fractal assembly can give rise to characteristic scaling between components that potentially include coexpressed transcripts. For key structural factors within the nucleus and extracellular matrix, we discover specific gene-gene scaling exponents across many of the 32 tumor types in The Cancer Genome Atlas, and we demonstrate utility in predicting patient survival as well as scaling-informed machine learning (SIML). All tumors with adjacent tissue data show cancer-elevated proliferation genes, with some genes scaling with the nuclear filament LMNB1, including the transcription factor FOXM1 that we show directly regulates LMNB1 SIML shows that such regulated cancers cluster together with longer overall survival than dysregulated cancers, but high LMNB1 and FOXM1 in half of regulated cancers surprisingly predict poor survival, including for liver cancer. COL1A1 is also studied because it too increases in tumors, and a pan-cancer set of fibrosis genes shows substoichiometric scaling with COL1A1 but predicts patient outcome only for liver cancer-unexpectedly being prosurvival. Single-cell RNA-seq data show nontrivial scaling consistent with power laws from bulk RNA and protein analyses, and SIML segregates synthetic from contractile cancer fibroblasts. Our scaling approach thus yields fundamentals-based power laws relatable to survival, gene function, and experiments.
Collapse
|
6
|
Pennarun G, Picotto J, Etourneaud L, Redavid AR, Certain A, Gauthier LR, Fontanilla-Ramirez P, Busso D, Chabance-Okumura C, Thézé B, Boussin FD, Bertrand P. Increase in lamin B1 promotes telomere instability by disrupting the shelterin complex in human cells. Nucleic Acids Res 2021; 49:9886-9905. [PMID: 34469544 PMCID: PMC8464066 DOI: 10.1093/nar/gkab761] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 08/04/2021] [Accepted: 08/31/2021] [Indexed: 12/19/2022] Open
Abstract
Telomere maintenance is essential to preserve genomic stability and involves telomere-specific proteins, DNA replication and repair proteins. Lamins are key components of the nuclear envelope and play numerous roles, including maintenance of the nuclear integrity, regulation of transcription, and DNA replication. Elevated levels of lamin B1, one of the major lamins, have been observed in some human pathologies and several cancers. Yet, the effect of lamin B1 dysregulation on telomere maintenance remains unknown. Here, we unveil that lamin B1 overexpression drives telomere instability through the disruption of the shelterin complex. Indeed, lamin B1 dysregulation leads to an increase in telomere dysfunction-induced foci, telomeric fusions and telomere losses in human cells. Telomere aberrations were preceded by mislocalizations of TRF2 and its binding partner RAP1. Interestingly, we identified new interactions between lamin B1 and these shelterin proteins, which are strongly enhanced at the nuclear periphery upon lamin B1 overexpression. Importantly, chromosomal fusions induced by lamin B1 in excess were rescued by TRF2 overexpression. These data indicated that lamin B1 overexpression triggers telomere instability through a mislocalization of TRF2. Altogether our results point to lamin B1 as a new interacting partner of TRF2, that is involved in telomere stability.
Collapse
Affiliation(s)
- Gaëlle Pennarun
- Université de Paris and Université Paris-Saclay, INSERM, iRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, F-92265 Fontenay-aux-Roses, France
- “DNA Repair and Ageing” Team, iRCM/IBFJ, DRF, CEA, Fontenay-aux-Roses, France
| | - Julien Picotto
- Université de Paris and Université Paris-Saclay, INSERM, iRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, F-92265 Fontenay-aux-Roses, France
- “DNA Repair and Ageing” Team, iRCM/IBFJ, DRF, CEA, Fontenay-aux-Roses, France
| | - Laure Etourneaud
- Université de Paris and Université Paris-Saclay, INSERM, iRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, F-92265 Fontenay-aux-Roses, France
- “DNA Repair and Ageing” Team, iRCM/IBFJ, DRF, CEA, Fontenay-aux-Roses, France
| | - Anna-Rita Redavid
- Université de Paris and Université Paris-Saclay, INSERM, iRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, F-92265 Fontenay-aux-Roses, France
- “DNA Repair and Ageing” Team, iRCM/IBFJ, DRF, CEA, Fontenay-aux-Roses, France
| | - Anaïs Certain
- Université de Paris and Université Paris-Saclay, INSERM, iRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, F-92265 Fontenay-aux-Roses, France
- “DNA Repair and Ageing” Team, iRCM/IBFJ, DRF, CEA, Fontenay-aux-Roses, France
| | - Laurent R Gauthier
- Université de Paris and Université Paris-Saclay, INSERM, iRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, F-92265 Fontenay-aux-Roses, France
- “Radiopathology” Team, iRCM/IBFJ, DRF, CEA, Fontenay-aux-Roses, France
| | - Paula Fontanilla-Ramirez
- Université de Paris and Université Paris-Saclay, INSERM, iRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, F-92265 Fontenay-aux-Roses, France
- “DNA Repair and Ageing” Team, iRCM/IBFJ, DRF, CEA, Fontenay-aux-Roses, France
| | - Didier Busso
- Université de Paris and Université Paris-Saclay, INSERM, iRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, F-92265 Fontenay-aux-Roses, France
- Genetic Engineering and Expression Platform (CIGEX), iRCM, DRF, CEA, Fontenay-aux-Roses, France
| | - Caroline Chabance-Okumura
- Université de Paris and Université Paris-Saclay, INSERM, iRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, F-92265 Fontenay-aux-Roses, France
- “DNA Repair and Ageing” Team, iRCM/IBFJ, DRF, CEA, Fontenay-aux-Roses, France
| | - Benoît Thézé
- Université de Paris and Université Paris-Saclay, INSERM, iRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, F-92265 Fontenay-aux-Roses, France
- “DNA Repair and Ageing” Team, iRCM/IBFJ, DRF, CEA, Fontenay-aux-Roses, France
| | - François D Boussin
- Université de Paris and Université Paris-Saclay, INSERM, iRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, F-92265 Fontenay-aux-Roses, France
- “Radiopathology” Team, iRCM/IBFJ, DRF, CEA, Fontenay-aux-Roses, France
| | - Pascale Bertrand
- Université de Paris and Université Paris-Saclay, INSERM, iRCM/IBFJ CEA, UMR Stabilité Génétique Cellules Souches et Radiations, F-92265 Fontenay-aux-Roses, France
- “DNA Repair and Ageing” Team, iRCM/IBFJ, DRF, CEA, Fontenay-aux-Roses, France
| |
Collapse
|
7
|
Thakur V, Tiburcio de Freitas J, Li Y, Zhang K, Savadelis A, Bedogni B. MT1-MMP-dependent ECM processing regulates laminB1 stability and mediates replication fork restart. PLoS One 2021; 16:e0253062. [PMID: 34237080 PMCID: PMC8266045 DOI: 10.1371/journal.pone.0253062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 05/27/2021] [Indexed: 12/12/2022] Open
Abstract
Radiotherapy remains a mainstay of treatment for a majority of cancer patients. We have previously shown that the membrane bound matrix metalloproteinase MT1-MMP confers radio- and chemotherapy resistance to breast cancer via processing of the ECM and activation of integrinβ1/FAK signaling. Here, we further discovered that the nuclear envelope protein laminB1 is a potential target of integrinβ1/FAK. FAK interacts with laminB1 contributing to its stability. Stable laminB1 is found at replication forks (RFs) where it is likely to allow the proper positioning of RF protection factors, thus preventing RF degradation. Indeed, restoration of laminB1 expression rescues replication fork stalling and collapse that occurs upon MT1-MMP inhibition, and reduces DNA damage in breast cancer cells. Together, these data highlight a novel mechanism of laminB1 stability and replication fork restart via MT1-MMP dependent extracelluar matrix remodeling.
Collapse
Affiliation(s)
- Varsha Thakur
- Department of Dermatology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Juliano Tiburcio de Freitas
- Department of Dermatology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Yuan Li
- Department of Dermatology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| | - Keman Zhang
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States of America
| | - Alyssa Savadelis
- Department of Biochemistry, Case Western Reserve University, Cleveland, OH, United States of America
| | - Barbara Bedogni
- Department of Dermatology, University of Miami Miller School of Medicine, Miami, FL, United States of America
| |
Collapse
|
8
|
Kychygina A, Dall'Osto M, Allen JAM, Cadoret JC, Piras V, Pickett HA, Crabbe L. Progerin impairs 3D genome organization and induces fragile telomeres by limiting the dNTP pools. Sci Rep 2021; 11:13195. [PMID: 34162976 PMCID: PMC8222272 DOI: 10.1038/s41598-021-92631-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 06/11/2021] [Indexed: 11/09/2022] Open
Abstract
Chromatin organization within the nuclear volume is essential to regulate many aspects of its function and to safeguard its integrity. A key player in this spatial scattering of chromosomes is the nuclear envelope (NE). The NE tethers large chromatin domains through interaction with the nuclear lamina and other associated proteins. This organization is perturbed in cells from Hutchinson–Gilford progeria syndrome (HGPS), a genetic disorder characterized by premature aging features. Here, we show that HGPS-related lamina defects trigger an altered 3D telomere organization with increased contact sites between telomeres and the nuclear lamina, and an altered telomeric chromatin state. The genome-wide replication timing signature of these cells is perturbed, with a shift to earlier replication for regions that normally replicate late. As a consequence, we detected a higher density of replication forks traveling simultaneously on DNA fibers, which relies on limiting cellular dNTP pools to support processive DNA synthesis. Remarkably, increasing dNTP levels in HGPS cells rescued fragile telomeres, and improved the replicative capacity of the cells. Our work highlights a functional connection between NE dysfunction and telomere homeostasis in the context of premature aging.
Collapse
Affiliation(s)
- Anna Kychygina
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Integrative (CBI), CNRS, UPS, University of Toulouse, 31062, Toulouse, France.,INSERM UMR1291, CNRS UMR5051, UT3, Toulouse Institute for Infectious and Inflammatory Diseases (Infinity), 31059, Toulouse, France
| | - Marina Dall'Osto
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Integrative (CBI), CNRS, UPS, University of Toulouse, 31062, Toulouse, France
| | - Joshua A M Allen
- Telomere Length Regulation Unit, Faculty of Medicine and Health, Children's Medical Research Institute, University of Sydney, Westmead, NSW, 2145, Australia
| | | | - Vincent Piras
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Integrative (CBI), CNRS, UPS, University of Toulouse, 31062, Toulouse, France
| | - Hilda A Pickett
- Telomere Length Regulation Unit, Faculty of Medicine and Health, Children's Medical Research Institute, University of Sydney, Westmead, NSW, 2145, Australia
| | - Laure Crabbe
- Molecular, Cellular and Developmental Biology Department (MCD), Centre de Biologie Integrative (CBI), CNRS, UPS, University of Toulouse, 31062, Toulouse, France.
| |
Collapse
|
9
|
The γ-tubulin meshwork assists in the recruitment of PCNA to chromatin in mammalian cells. Commun Biol 2021; 4:767. [PMID: 34158617 PMCID: PMC8219688 DOI: 10.1038/s42003-021-02280-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 05/28/2021] [Indexed: 12/27/2022] Open
Abstract
Changes in the location of γ-tubulin ensure cell survival and preserve genome integrity. We investigated whether the nuclear accumulation of γ-tubulin facilitates the transport of proliferating cell nuclear antigen (PCNA) between the cytosolic and the nuclear compartment in mammalian cells. We found that the γ-tubulin meshwork assists in the recruitment of PCNA to chromatin. Also, decreased levels of γ-tubulin reduce the nuclear pool of PCNA. In addition, the γ-tubulin C terminus encodes a PCNA-interacting peptide (PIP) motif, and a γ-tubulin–PIP-mutant affects the nuclear accumulation of PCNA. In a cell-free system, PCNA and γ-tubulin formed a complex. In tumors, there is a significant positive correlation between TUBG1 and PCNA expression. Thus, we report a novel mechanism that constitutes the basis for tumor growth by which the γ-tubulin meshwork maintains indefinite proliferation by acting as an opportune scaffold for the transport of PCNA from the cytosol to the chromatin. Corvaisier et al discover that γ-tubulin and replication protein PCNA forms a complex and that this facilitates recruitment of PCNA to chromatin both during cell division and during the DSB repair response. They identify a PCNA binding motif in γ-tubulin, which when mutated affects replication fork progression, providing insights into the role of the nuclear γ-tubulin meshwork.
Collapse
|
10
|
Willaume S, Rass E, Fontanilla-Ramirez P, Moussa A, Wanschoor P, Bertrand P. A Link between Replicative Stress, Lamin Proteins, and Inflammation. Genes (Basel) 2021; 12:genes12040552. [PMID: 33918867 PMCID: PMC8070205 DOI: 10.3390/genes12040552] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 03/23/2021] [Accepted: 04/08/2021] [Indexed: 12/12/2022] Open
Abstract
Double-stranded breaks (DSB), the most toxic DNA lesions, are either a consequence of cellular metabolism, programmed as in during V(D)J recombination, or induced by anti-tumoral therapies or accidental genotoxic exposure. One origin of DSB sources is replicative stress, a major source of genome instability, especially when the integrity of the replication forks is not properly guaranteed. To complete stalled replication, restarting the fork requires complex molecular mechanisms, such as protection, remodeling, and processing. Recently, a link has been made between DNA damage accumulation and inflammation. Indeed, defects in DNA repair or in replication can lead to the release of DNA fragments in the cytosol. The recognition of this self-DNA by DNA sensors leads to the production of inflammatory factors. This beneficial response activating an innate immune response and destruction of cells bearing DNA damage may be considered as a novel part of DNA damage response. However, upon accumulation of DNA damage, a chronic inflammatory cellular microenvironment may lead to inflammatory pathologies, aging, and progression of tumor cells. Progress in understanding the molecular mechanisms of DNA damage repair, replication stress, and cytosolic DNA production would allow to propose new therapeutical strategies against cancer or inflammatory diseases associated with aging. In this review, we describe the mechanisms involved in DSB repair, the replicative stress management, and its consequences. We also focus on new emerging links between key components of the nuclear envelope, the lamins, and DNA repair, management of replicative stress, and inflammation.
Collapse
|
11
|
A targeted antisense therapeutic approach for Hutchinson-Gilford progeria syndrome. Nat Med 2021; 27:536-545. [PMID: 33707773 PMCID: PMC10158310 DOI: 10.1038/s41591-021-01274-0] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 02/01/2021] [Indexed: 12/12/2022]
Abstract
Hutchinson-Gilford progeria syndrome (HGPS) is a rare accelerated aging disorder characterized by premature death from myocardial infarction or stroke. It is caused by de novo single-nucleotide mutations in the LMNA gene that activate a cryptic splice donor site, resulting in the production of a toxic form of lamin A, which is termed progerin. Here we present a potential genetic therapeutic strategy that utilizes antisense peptide-conjugated phosphorodiamidate morpholino oligomers (PPMOs) to block pathogenic splicing of mutant transcripts. Of several candidates, PPMO SRP-2001 provided the most significant decrease in progerin transcripts in patient fibroblasts. Intravenous delivery of SRP-2001 to a transgenic mouse model of HGPS produced significant reduction of progerin transcripts in the aorta, a particularly critical target tissue in HGPS. Long-term continuous treatment with SRP-2001 yielded a 61.6% increase in lifespan and rescue of vascular smooth muscle cell loss in large arteries. These results provide a rationale for proceeding to human trials.
Collapse
|
12
|
Gil L, Niño SA, Capdeville G, Jiménez-Capdeville ME. Aging and Alzheimer's disease connection: Nuclear Tau and lamin A. Neurosci Lett 2021; 749:135741. [PMID: 33610669 DOI: 10.1016/j.neulet.2021.135741] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 01/12/2021] [Accepted: 02/11/2021] [Indexed: 12/24/2022]
Abstract
Age-related pathologies like Alzheimer`s disease (AD) imply cellular responses directed towards repairing DNA damage. Postmitotic neurons show progressive accumulation of oxidized DNA during decades of brain aging, which is especially remarkable in AD brains. The characteristic cytoskeletal pathology of AD neurons is brought about by the progressive changes that neurons undergo throughout aging, and their irreversible nuclear transformation initiates the disease. This review focusses on critical molecular events leading to the loss of plasticity that underlies cognitive deficits in AD. During healthy neuronal aging, nuclear Tau participates in the regulation of the structure and function of the chromatin. The aberrant cell cycle reentry initiated for DNA repair triggers a cascade of events leading to the dysfunctional AD neuron, whereby Tau protein exits the nucleus leading to chromatin disorganization. Lamin A, which is not typically expressed in neurons, appears at the transformation from senile to AD neurons and contributes to halting the consequences of cell cycle reentry and nuclear Tau exit, allowing the survival of the neuron. Nevertheless, this irreversible nuclear transformation alters the nucleic acid and protein synthesis machinery as well as the nuclear lamina and cytoskeleton structures, leading to neurofibrillary tangles formation and final neurodegeneration.
Collapse
Affiliation(s)
- Laura Gil
- Departamento de Genética, Escuela de Medicina, Universidad "Alfonso X el Sabio", Madrid, Spain
| | - Sandra A Niño
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, Mexico
| | | | | |
Collapse
|
13
|
Ikegami K, Secchia S, Almakki O, Lieb JD, Moskowitz IP. Phosphorylated Lamin A/C in the Nuclear Interior Binds Active Enhancers Associated with Abnormal Transcription in Progeria. Dev Cell 2020; 52:699-713.e11. [PMID: 32208162 DOI: 10.1016/j.devcel.2020.02.011] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 12/13/2019] [Accepted: 02/13/2020] [Indexed: 02/06/2023]
Abstract
LMNA encodes nuclear Lamin A/C that tethers lamina-associated domains (LADs) to the nuclear periphery. Mutations in LMNA cause degenerative disorders including the premature aging disorder Hutchinson-Gilford progeria, but the mechanisms are unknown. We report that Ser22-phosphorylated (pS22) Lamin A/C was localized to the nuclear interior in human fibroblasts throughout the cell cycle. pS22-Lamin A/C interacted with a subset of putative active enhancers, not LADs, at locations co-bound by the transcriptional activator c-Jun. In progeria-patient fibroblasts, a subset of pS22-Lamin A/C-binding sites were lost, whereas new pS22-Lamin A/C-binding sites emerged in normally quiescent loci. New pS22-Lamin A/C binding was accompanied by increased histone acetylation, increased c-Jun binding, and upregulation of nearby genes implicated in progeria pathophysiology. These results suggest that Lamin A/C regulates gene expression by enhancer binding. Disruption of the gene regulatory rather than LAD tethering function of Lamin A/C may underlie the pathogenesis of disorders caused by LMNA mutations.
Collapse
Affiliation(s)
- Kohta Ikegami
- Department of Pediatrics, The University of Chicago, Chicago, IL 60637, USA; Department of Human Genetics, The University of Chicago, Chicago, IL 60637, USA.
| | - Stefano Secchia
- Department of Human Genetics, The University of Chicago, Chicago, IL 60637, USA; Department of Biology, Lunds University, Lund 22362, Sweden
| | - Omar Almakki
- Department of Pediatrics, The University of Chicago, Chicago, IL 60637, USA
| | - Jason D Lieb
- Department of Human Genetics, The University of Chicago, Chicago, IL 60637, USA
| | - Ivan P Moskowitz
- Department of Pediatrics, The University of Chicago, Chicago, IL 60637, USA; Department of Human Genetics, The University of Chicago, Chicago, IL 60637, USA; Department of Pathology, The University of Chicago, Chicago, IL 60637, USA
| |
Collapse
|
14
|
Emerging roles of lamins and DNA damage repair mechanisms in ovarian cancer. Biochem Soc Trans 2020; 48:2317-2333. [DOI: 10.1042/bst20200713] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 09/14/2020] [Accepted: 09/21/2020] [Indexed: 02/06/2023]
Abstract
Lamins are type V intermediate filament proteins which are ubiquitously present in all metazoan cells providing a platform for binding of chromatin and related proteins, thereby serving a wide range of nuclear functions including DNA damage repair. Altered expression of lamins in different subtypes of cancer is evident from researches worldwide. But whether cancer is a consequence of this change or this change is a consequence of cancer is a matter of future investigation. However changes in the expression levels of lamins is reported to have direct or indirect association with cancer progression or have regulatory roles in common neoplastic symptoms like higher nuclear deformability, increased genomic instability and reduced susceptibility to DNA damaging agents. It has already been proved that loss of A type lamin positively regulates cathepsin L, eventually leading to degradation of several DNA damage repair proteins, hence impairing DNA damage repair pathways and increasing genomic instability. It is established in ovarian cancer, that the extent of alteration in nuclear morphology can determine the degree of genetic changes and thus can be utilized to detect low to high form of serous carcinoma. In this review, we have focused on ovarian cancer which is largely caused by genomic alterations in the DNA damage response pathways utilizing proteins like RAD51, BRCA1, 53BP1 which are regulated by lamins. We have elucidated the current understanding of lamin expression in ovarian cancer and its implications in the regulation of DNA damage response pathways that ultimately result in telomere deformation and genomic instability.
Collapse
|
15
|
van Schaik T, Vos M, Peric-Hupkes D, Hn Celie P, van Steensel B. Cell cycle dynamics of lamina-associated DNA. EMBO Rep 2020; 21:e50636. [PMID: 32893442 PMCID: PMC7645246 DOI: 10.15252/embr.202050636] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 08/07/2020] [Accepted: 08/11/2020] [Indexed: 12/12/2022] Open
Abstract
In mammalian interphase nuclei, more than one thousand large genomic regions are positioned at the nuclear lamina (NL). These lamina‐associated domains (LADs) are involved in gene regulation and may provide a backbone for the folding of interphase chromosomes. Little is known about the dynamics of LADs during interphase, in particular at the onset of G1 phase and during DNA replication. We developed an antibody‐based variant of the DamID technology (named pA‐DamID) that allows us to map and visualize genome–NL interactions with high temporal resolution. Application of pA‐DamID combined with synchronization and cell sorting experiments reveals that LAD–NL contacts are generally rapidly established early in G1 phase. However, LADs on the distal ~25 Mb of most chromosomes tend to contact the NL first and then gradually detach, while centromere‐proximal LADs accumulate gradually at the NL. Furthermore, our data indicate that S‐phase chromatin shows transiently increased lamin interactions. These findings highlight a dynamic choreography of LAD–NL contacts during interphase progression and illustrate the usefulness of pA‐DamID to study the dynamics of genome compartmentalization.
Collapse
Affiliation(s)
- Tom van Schaik
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Mabel Vos
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Daan Peric-Hupkes
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Patrick Hn Celie
- Protein Facility, Oncode Institute, Netherlands Cancer Institute, Amsterdam, The Netherlands
| | - Bas van Steensel
- Division of Gene Regulation, Netherlands Cancer Institute, Amsterdam, The Netherlands.,Department of Cell Biology, Erasmus University Medical Center, Rotterdam, The Netherlands
| |
Collapse
|
16
|
Gil L, Niño SA, Chi-Ahumada E, Rodríguez-Leyva I, Guerrero C, Rebolledo AB, Arias JA, Jiménez-Capdeville ME. Perinuclear Lamin A and Nucleoplasmic Lamin B2 Characterize Two Types of Hippocampal Neurons through Alzheimer's Disease Progression. Int J Mol Sci 2020; 21:E1841. [PMID: 32155994 PMCID: PMC7084765 DOI: 10.3390/ijms21051841] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 02/28/2020] [Accepted: 03/03/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND Recent reports point to a nuclear origin of Alzheimer's disease (AD). Aged postmitotic neurons try to repair their damaged DNA by entering the cell cycle. This aberrant cell cycle re-entry involves chromatin modifications where nuclear Tau and the nuclear lamin are involved. The purpose of this work was to elucidate their participation in the nuclear pathological transformation of neurons at early AD. METHODOLOGY The study was performed in hippocampal paraffin embedded sections of adult, senile, and AD brains at I-VI Braak stages. We analyzed phospho-Tau, lamins A, B1, B2, and C, nucleophosmin (B23) and the epigenetic marker H4K20me3 by immunohistochemistry. RESULTS Two neuronal populations were found across AD stages, one is characterized by a significant increase of Lamin A expression, reinforced perinuclear Lamin B2, elevated expression of H4K20me3 and nuclear Tau loss, while neurons with nucleoplasmic Lamin B2 constitute a second population. CONCLUSIONS The abnormal cell cycle reentry in early AD implies a fundamental neuronal transformation. This implies the reorganization of the nucleo-cytoskeleton through the expression of the highly regulated Lamin A, heterochromatin repression and building of toxic neuronal tangles. This work demonstrates that nuclear Tau and lamin modifications in hippocampal neurons are crucial events in age-related neurodegeneration.
Collapse
Affiliation(s)
- Laura Gil
- Departamento de Genética, Escuela de Medicina, Universidad “Alfonso X el Sabio”, 28691 Madrid, Spain; (L.G.)
| | - Sandra A. Niño
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí 78210, Mexico
| | - Erika Chi-Ahumada
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí 78210, Mexico
| | | | - Carmen Guerrero
- Banco de cerebros (Biobanco), Hospital Universitario Fundación Alcorcón, Alcorcón, 28922 Madrid, Spain
| | - Ana Belén Rebolledo
- Banco de cerebros (Biobanco), Hospital Universitario Fundación Alcorcón, Alcorcón, 28922 Madrid, Spain
| | - José A. Arias
- Departamento de Genética, Escuela de Medicina, Universidad “Alfonso X el Sabio”, 28691 Madrid, Spain; (L.G.)
| | - María E. Jiménez-Capdeville
- Departamento de Bioquímica, Facultad de Medicina, Universidad Autónoma de San Luis Potosí, San Luis Potosí 78210, Mexico
| |
Collapse
|
17
|
Chen NY, Yang Y, Weston TA, Belling JN, Heizer P, Tu Y, Kim P, Edillo L, Jonas SJ, Weiss PS, Fong LG, Young SG. An absence of lamin B1 in migrating neurons causes nuclear membrane ruptures and cell death. Proc Natl Acad Sci U S A 2019; 116:25870-25879. [PMID: 31796586 PMCID: PMC6926041 DOI: 10.1073/pnas.1917225116] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Deficiencies in either lamin B1 or lamin B2 cause both defective migration of cortical neurons in the developing brain and reduced neuronal survival. The neuronal migration abnormality is explained by a weakened nuclear lamina that interferes with nucleokinesis, a nuclear translocation process required for neuronal migration. In contrast, the explanation for impaired neuronal survival is poorly understood. We hypothesized that the forces imparted on the nucleus during neuronal migration result in nuclear membrane (NM) ruptures, causing interspersion of nuclear and cytoplasmic contents-and ultimately cell death. To test this hypothesis, we bred Lmnb1-deficient mice that express a nuclear-localized fluorescent Cre reporter. Migrating neurons within the cortical plate of E18.5 Lmnb1-deficient embryos exhibited NM ruptures, evident by the escape of the nuclear-localized reporter into the cytoplasm and NM discontinuities by electron microscopy. The NM ruptures were accompanied by DNA damage and cell death. The NM ruptures were not observed in nonmigrating cells within the ventricular zone. NM ruptures, DNA damage, and cell death were also observed in cultured Lmnb1-/- and Lmnb2-/- neurons as they migrated away from neurospheres. To test whether mechanical forces on the cell nucleus are relevant to NM ruptures in migrating neurons, we examined cultured Lmnb1-/- neurons when exposed to external constrictive forces (migration into a field of tightly spaced silicon pillars). As the cells entered the field of pillars, there were frequent NM ruptures, accompanied by DNA damage and cell death.
Collapse
Affiliation(s)
- Natalie Y Chen
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Ye Yang
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Thomas A Weston
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Jason N Belling
- California NanoSystems Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Patrick Heizer
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Yiping Tu
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Paul Kim
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Lovelyn Edillo
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| | - Steven J Jonas
- Department of Pediatrics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Children's Discovery and Innovation Institute, University of California, Los Angeles, CA 90095
- Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, CA 90095
| | - Paul S Weiss
- California NanoSystems Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Chemistry and Biochemistry, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Department of Bioengineering, University of California, Los Angeles, CA 90095
- Department of Materials Science and Engineering, University of California, Los Angeles, CA 90095
| | - Loren G Fong
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095;
| | - Stephen G Young
- Department of Medicine, David Geffen School of Medicine, University of California, Los Angeles, CA 90095;
- Department of Human Genetics, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
- Molecular Biology Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095
| |
Collapse
|
18
|
Graziano S, Kreienkamp R, Coll-Bonfill N, Gonzalo S. Causes and consequences of genomic instability in laminopathies: Replication stress and interferon response. Nucleus 2019; 9:258-275. [PMID: 29637811 PMCID: PMC5973265 DOI: 10.1080/19491034.2018.1454168] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Mammalian nuclei are equipped with a framework of intermediate filaments that function as a karyoskeleton. This nuclear scaffold, formed primarily by lamins (A-type and B-type), maintains the spatial and functional organization of the genome and of sub-nuclear compartments. Over the past decade, a body of evidence has highlighted the significance of these structural nuclear proteins in the maintenance of nuclear architecture and mechanical stability, as well as genome function and integrity. The importance of these structures is now unquestioned given the wide range of degenerative diseases that stem from LMNA gene mutations, including muscular dystrophy disorders, peripheral neuropathies, lipodystrophies, and premature aging syndromes. Here, we review our knowledge about how alterations in nuclear lamins, either by mutation or reduced expression, impact cellular mechanisms that maintain genome integrity. Despite the fact that DNA replication is the major source of DNA damage and genomic instability in dividing cells, how alterations in lamins function impact replication remains minimally explored. We summarize recent studies showing that lamins play a role in DNA replication, and that the DNA damage that accumulates upon lamins dysfunction is elicited in part by deprotection of replication forks. We also discuss the emerging model that DNA damage and replication stress are “sensed” at the cytoplasm by proteins that normally survey this space in search of foreign nucleic acids. In turn, these cytosolic sensors activate innate immune responses, which are materializing as important players in aging and cancer, as well as in the response to cancer immunotherapy.
Collapse
Affiliation(s)
- Simona Graziano
- a Edward A. Doisy Department of Biochemistry and Molecular Biology , Saint Louis University School of Medicine , St. Louis , MO , USA
| | - Ray Kreienkamp
- a Edward A. Doisy Department of Biochemistry and Molecular Biology , Saint Louis University School of Medicine , St. Louis , MO , USA
| | - Nuria Coll-Bonfill
- a Edward A. Doisy Department of Biochemistry and Molecular Biology , Saint Louis University School of Medicine , St. Louis , MO , USA
| | - Susana Gonzalo
- a Edward A. Doisy Department of Biochemistry and Molecular Biology , Saint Louis University School of Medicine , St. Louis , MO , USA
| |
Collapse
|
19
|
Pentagalloylglucose Inhibits the Replication of Rabies Virus via Mediation of the miR-455/SOCS3/STAT3/IL-6 Pathway. J Virol 2019; 93:JVI.00539-19. [PMID: 31243136 DOI: 10.1128/jvi.00539-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2019] [Accepted: 06/23/2019] [Indexed: 02/07/2023] Open
Abstract
Our previous study showed that pentagalloylglucose (PGG), a naturally occurring hydrolyzable phenolic tannin, possesses significant anti-rabies virus (RABV) activity. In BHK-21 cells, RABV induced the overactivation of signal transducer and activator of transcription 3 (STAT3) by suppressing the expression of suppressor of cytokine signaling 3 (SOCS3). Inhibition of STAT3 by niclosamide, small interfering RNA, or exogenous expression of SOCS3 all significantly suppressed the replication of RABV. Additionally, RABV-induced upregulation of microRNA 455-5p (miR-455-5p) downregulated SOCS3 by directly binding to the 3' untranslated region (UTR) of SOCS3. Importantly, PGG effectively reversed the expression of miR-455-5p and its following SOCS3/STAT3 signaling pathway. Finally, activated STAT3 elicited the expression of interleukin-6 (IL-6), thereby contributing to RABV-associated encephalomyelitis; however, PGG restored the level of IL-6 in vitro and in vivo in a SOCS3/STAT3-dependent manner. Altogether, these data identify a new miR-455-5p/SOCS3/STAT3 signaling pathway that contributes to viral replication and IL-6 production in RABV-infected cells, with PGG exerting its antiviral effect by inhibiting the production of miR-455-5p and the activation of STAT3.IMPORTANCE Rabies virus causes lethal encephalitis in mammals and poses a serious public health threat in many parts of the world. Numerous strategies have been explored to combat rabies; however, their efficacy has always been unsatisfactory. We previously reported a new drug, PGG, which possesses a potent inhibitory activity on RABV replication. Herein, we describe the underlying mechanisms by which PGG exerts its anti-RABV activity. Our results show that RABV induces overactivation of STAT3 in BHK-21 cells, which facilitates viral replication. Importantly, PGG effectively inhibits the activity of STAT3 by disrupting the expression of miR-455-5p and increases the level of SOCS3 by directly targeting the 3' UTR of SOCS3. Furthermore, the downregulated STAT3 inhibits the production of IL-6, thereby contributing to a reduction in the inflammatory response in vivo Our study indicates that PGG effectively inhibits the replication of RABV by the miR-455-5p/SOCS3/STAT3/IL-6-dependent pathway.
Collapse
|
20
|
Kreienkamp R, Gonzalo S. Hutchinson-Gilford Progeria Syndrome: Challenges at Bench and Bedside. Subcell Biochem 2019; 91:435-451. [PMID: 30888661 DOI: 10.1007/978-981-13-3681-2_15] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
The structural nuclear proteins known as "lamins" (A-type and B-type) provide a scaffold for the compartmentalization of genome function that is important to maintain genome stability. Mutations in the LMNA gene -encoding for A-type lamins- are associated with over a dozen of degenerative disorders termed laminopathies, which include muscular dystrophies, lipodystrophies, neuropathies, and premature ageing diseases such as Hutchinson Gilford Progeria Syndrome (HGPS). This devastating disease is caused by the expression of a truncated lamin A protein named "progerin". To date, there is no effective treatment for HGPS patients, who die in their teens from cardiovascular disease. At a cellular level, progerin expression impacts nuclear architecture, chromatin organization, response to mechanical stress, and DNA transactions such as transcription, replication and repair. However, the current view is that key mechanisms behind progerin toxicity still remain to be discovered. Here, we discuss new findings about pathological mechanisms in HGPS, especially the contribution of replication stress to cellular decline, and therapeutic strategies to ameliorate progerin toxicity. In particular, we present evidence for retinoids and calcitriol (hormonal vitamin D metabolite) being among the most potent compounds to ameliorate HGPS cellular phenotypes in vitro, providing the rationale for testing these compounds in preclinical models of the disease in the near term, and in patients in the future.
Collapse
Affiliation(s)
- Ray Kreienkamp
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Doisy Research Center, St Louis University School of Medicine, St. Louis, MO, USA
| | - Susana Gonzalo
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Doisy Research Center, St Louis University School of Medicine, St. Louis, MO, USA.
| |
Collapse
|
21
|
Alvarado-Kristensson M, Rosselló CA. The Biology of the Nuclear Envelope and Its Implications in Cancer Biology. Int J Mol Sci 2019; 20:E2586. [PMID: 31137762 PMCID: PMC6566445 DOI: 10.3390/ijms20102586] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2019] [Revised: 05/07/2019] [Accepted: 05/25/2019] [Indexed: 12/18/2022] Open
Abstract
The formation of the nuclear envelope and the subsequent compartmentalization of the genome is a defining feature of eukaryotes. Traditionally, the nuclear envelope was purely viewed as a physical barrier to preserve genetic material in eukaryotic cells. However, in the last few decades, it has been revealed to be a critical cellular component in controlling gene expression and has been implicated in several human diseases. In cancer, the relevance of the cell nucleus was first reported in the mid-1800s when an altered nuclear morphology was observed in tumor cells. This review aims to give a current and comprehensive view of the role of the nuclear envelope on cancer first by recapitulating the changes of the nuclear envelope during cell division, second, by reviewing the role of the nuclear envelope in cell cycle regulation, signaling, and the regulation of the genome, and finally, by addressing the nuclear envelope link to cell migration and metastasis and its use in cancer prognosis.
Collapse
Affiliation(s)
- Maria Alvarado-Kristensson
- Molecular Pathology, Department of Translational Medicine, Lund University, Skåne University Hospital, 20502 Malmö, Sweden.
| | - Catalina Ana Rosselló
- Laboratory of Molecular Cell Biomedicine, University of the Balearic Islands, 07121 Palma de Mallorca, Spain.
- Lipopharma Therapeutics, Isaac Newton, 07121 Palma de Mallorca, Spain.
| |
Collapse
|
22
|
Kinesin-14 motor protein KIFC1 participates in DNA synthesis and chromatin maintenance. Cell Death Dis 2019; 10:402. [PMID: 31127080 PMCID: PMC6534603 DOI: 10.1038/s41419-019-1619-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Revised: 03/02/2019] [Accepted: 04/29/2019] [Indexed: 11/09/2022]
Abstract
The nuclear localization signal (NLS) in kinesin-14 KIFC1 is associated with nuclear importins and Ran gradient, but detailed mechanism remains unknown. In this study, we found that KIFC1 proteins have specific transport characteristics during cell cycle. In the absence of KIFC1, cell cycle kinetics decrease significantly with a prolonged S phase. After KIFC1 overexpression, the duration of S phase becomes shorten. KIFC1 may transport the recombinant/replicate-related proteins into the nucleus, meanwhile avoiding excessive KIFC1 in the cytoplasm, which results in aberrant microtubule bundling. Interestingly, the deletion of kifc1 in human cells results in a higher ratio of aberrant nuclear membrane, and the degradation of lamin B and lamin A/C. We also found that kifc1 deletion leads to defects in metaphase mitotic spindle assembly, and then results in chromosome structural abnormality. The kifc1-/- cells finally form micronuclei in daughter cells, and results in aneuploidy and chromosome loss in cell cycle. In this study, we demonstrate that kinesin-14 KIFC1 proteins involve in regulating DNA synthesis in S phase, and chromatin maintenance in mitosis, and maintain cell growth in a nuclear transport-independent way.
Collapse
|
23
|
Clements CS, Bikkul MU, Ofosu W, Eskiw C, Tree D, Makarov E, Kill IR, Bridger JM. Presence and distribution of progerin in HGPS cells is ameliorated by drugs that impact on the mevalonate and mTOR pathways. Biogerontology 2019; 20:337-358. [PMID: 31041622 PMCID: PMC6535420 DOI: 10.1007/s10522-019-09807-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 03/29/2019] [Indexed: 12/12/2022]
Abstract
Hutchinson-Gilford progeria syndrome (HGPS) is a rare, premature ageing syndrome in children. HGPS is normally caused by a mutation in the LMNA gene, encoding nuclear lamin A. The classical mutation in HGPS leads to the production of a toxic truncated version of lamin A, progerin, which retains a farnesyl group. Farnesyltransferase inhibitors (FTI), pravastatin and zoledronic acid have been used in clinical trials to target the mevalonate pathway in HGPS patients to inhibit farnesylation of progerin, in order to reduce its toxicity. Some other compounds that have been suggested as treatments include rapamycin, IGF1 and N-acetyl cysteine (NAC). We have analysed the distribution of prelamin A, lamin A, lamin A/C, progerin, lamin B1 and B2 in nuclei of HGPS cells before and after treatments with these drugs, an FTI and a geranylgeranyltransferase inhibitor (GGTI) and FTI with pravastatin and zoledronic acid in combination. Confirming other studies prelamin A, lamin A, progerin and lamin B2 staining was different between control and HGPS fibroblasts. The drugs that reduced progerin staining were FTI, pravastatin, zoledronic acid and rapamycin. However, drugs affecting the mevalonate pathway increased prelamin A, with only FTI reducing internal prelamin A foci. The distribution of lamin A in HGPS cells was improved with treatments of FTI, pravastatin and FTI + GGTI. All treatments reduced the number of cells displaying internal speckles of lamin A/C and lamin B2. Drugs targeting the mevalonate pathway worked best for progerin reduction, with zoledronic acid removing internal progerin speckles. Rapamycin and NAC, which impact on the MTOR pathway, both reduced both pools of progerin without increasing prelamin A in HGPS cell nuclei.
Collapse
Affiliation(s)
- Craig S Clements
- Progeria Research Team, Ageing Studies Theme, Institute for Environment, Health and Societies, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, UK
| | - Mehmet U Bikkul
- Progeria Research Team, Ageing Studies Theme, Institute for Environment, Health and Societies, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, UK
| | - Wendy Ofosu
- Progeria Research Team, Ageing Studies Theme, Institute for Environment, Health and Societies, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, UK.,Department of Biomedical Sciences, University of Westminster, 115 New Cavendish Street, London, W1W 6UW, UK
| | - Christopher Eskiw
- Food and Bioproduct Sciences, College of Agriculture and Bioresources, University of Saskatchewan, 51 Campus Drive, Saskatoon, SK, S7B 5A8, Canada
| | - David Tree
- Progeria Research Team, Ageing Studies Theme, Institute for Environment, Health and Societies, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, UK
| | - Evgeny Makarov
- Progeria Research Team, Ageing Studies Theme, Institute for Environment, Health and Societies, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, UK
| | - Ian R Kill
- Progeria Research Team, Ageing Studies Theme, Institute for Environment, Health and Societies, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, UK
| | - Joanna M Bridger
- Progeria Research Team, Ageing Studies Theme, Institute for Environment, Health and Societies, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, UK. .,Genome Engineering and Maintenance Network, Ageing Studies Theme, Institute of Environment, Health and Societies, Brunel University London, Kingston Lane, Uxbridge, UB8 3PH, UK.
| |
Collapse
|
24
|
Du ZH, Chen J, Chen QG, Zhou LQ, Bing D, Liu Y, Sun YB, Li PJ, Qi F, Zhu HM, Chu HQ. Expression Patterns and Implications of LaminB1 in Rat Cochleae. Curr Med Sci 2019; 39:305-309. [PMID: 31016526 DOI: 10.1007/s11596-019-2035-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 03/13/2019] [Indexed: 01/22/2023]
Abstract
LaminB1, a major component of the nuclear lamina, is a potent regulator of cellular proliferation and senescence and also known to be essential for neuronal migration and brain development. However, the expression patterns of LaminB1 in the rat cochleae are still not fully revealed. Utilizing immunofluorescence, Western blotting, and quantitative real-time PCR, we identified the distribution and expression of LaminB1 in the rat cochleae. Immunofluorescence staining indicated that LaminB1 was mainly localized in the auditory hair cells (HCs), spiral ganglion cells (SGC), stria vascularis (STV, including spiral ligament), Reissner's membrane (RM), and limbus laminae spiralis (LLS). Western blotting analysis illustrated that the distribution of LaminB1 in rat cochleae was characterized by tissue specificity. The LaminB1 protein was expressed more in SGC and basilar membrane (BM) than in STV. Meanwhile, the mRNA expression of LaminB1 displayed difference in cochlear tissues. These observations preliminarily revealed the expression patterns of LaminB1, providing a theoretical basis for further study on the role of LaminB1 in auditory function.
Collapse
Affiliation(s)
- Zhi-Hui Du
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Jin Chen
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Qing-Guo Chen
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Liang-Qiang Zhou
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Dan Bing
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yun Liu
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yan-Bo Sun
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Peng-Jun Li
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Fan Qi
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Hong-Mei Zhu
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Han-Qi Chu
- Department of Otolaryngology-Head and Neck Surgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| |
Collapse
|
25
|
Bártová E, Legartová S, Krejčí J, Řezníčková P, Kovaříková AS, Suchánková J, Fedr R, Smirnov E, Hornáček M, Raška I. Depletion of A-type lamins and Lap2α reduces 53BP1 accumulation at UV-induced DNA lesions and Lap2α protein is responsible for compactness of irradiated chromatin. J Cell Biochem 2018; 119:8146-8162. [PMID: 29923310 DOI: 10.1002/jcb.26770] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 02/02/2018] [Indexed: 12/29/2022]
Abstract
We studied how deficiency in lamins A/C and lamina-associated polypeptide 2α (Lap2α) affects DNA repair after irradiation. A-type lamins and Lap2α were not recruited to local DNA lesions and did not accumulate to γ-irradiation-induced foci (IRIF), as it is generally observed for well-known marker of DNA lesions, 53BP1 protein. At micro-irradiated chromatin of lmna double knockout (dn) and Lap2α dn cells, 53BP1 protein levels were reduced, compared to locally irradiated wild-type counterpart. Decreased levels of 53BP1 we also observed in whole populations of lmna dn and Lap2α dn cells, irradiated by UV light. We also studied distribution pattern of 53BP1 protein in a genome outside micro-irradiated region. In Lap2α deficient cells, identical fluorescence of mCherry-tagged 53BP1 protein was found at both microirradiated region and surrounding chromatin. However, a well-known marker of double strand breaks, γH2AX, was highly abundant in the lesion-surrounding genome of Lap2α deficient cells. Described changes, induced by irradiation in Lap2α dn cells, were not accompanied by cell cycle changes. In Lap2α dn cells, we additionally performed analysis by FLIM (Fluorescence Lifetime Imaging Microscopy) that showed different dynamic behavior of mCherry-tagged 53BP1 protein pools when it was compared with wild-type (wt) fibroblasts. This analysis revealed three different fractions of mCherry-53BP1 protein. Two of them showed identical exponential decay times (τ1 and τ3), but the decay rate of τ2 and amplitudes of fluorescence decays (A1-A3) were statistically different in wt and Lap2α dn fibroblasts. Moreover, γ-irradiation weakened an interaction between A-type lamins and Lap2α. Together, our results demonstrate how depletion of Lap2α affects DNA damage response (DDR) and how chromatin compactness is changed in Lap2α deficient cells exposed to radiation.
Collapse
Affiliation(s)
- Eva Bártová
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
| | - Soňa Legartová
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
| | - Jana Krejčí
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
| | - Petra Řezníčková
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
| | | | - Jana Suchánková
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
| | - Radek Fedr
- Institute of Biophysics of the Czech Academy of Sciences, Brno, Czech Republic
| | - Evgeny Smirnov
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Matúš Hornáček
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| | - Ivan Raška
- Institute of Biology and Medical Genetics, First Faculty of Medicine, Charles University in Prague, Prague, Czech Republic
| |
Collapse
|
26
|
Fibroblasts lacking nuclear lamins do not have nuclear blebs or protrusions but nevertheless have frequent nuclear membrane ruptures. Proc Natl Acad Sci U S A 2018; 115:10100-10105. [PMID: 30224463 DOI: 10.1073/pnas.1812622115] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The nuclear lamina, an intermediate filament meshwork lining the inner nuclear membrane, is formed by the nuclear lamins (lamins A, C, B1, and B2). Defects or deficiencies in individual nuclear lamin proteins have been reported to elicit nuclear blebs (protrusions or outpouchings of the nuclear envelope) and increase susceptibility for nuclear membrane ruptures. It is unclear, however, how a complete absence of nuclear lamins would affect nuclear envelope morphology and nuclear membrane integrity (i.e., whether nuclear membrane blebs or protrusions would occur and, if not, whether cells would be susceptible to nuclear membrane ruptures). To address these issues, we generated mouse embryonic fibroblasts (MEFs) lacking all nuclear lamins. The nuclear lamin-deficient MEFs had irregular nuclear shapes but no nuclear blebs or protrusions. Despite a virtual absence of nuclear blebs, MEFs lacking nuclear lamins had frequent, prolonged, and occasionally nonhealing nuclear membrane ruptures. By transmission electron microscopy, the inner nuclear membrane in nuclear lamin-deficient MEFs have a "wavy" appearance, and there were discrete discontinuities in the inner and outer nuclear membranes. Nuclear membrane ruptures were accompanied by a large increase in DNA damage, as judged by γ-H2AX foci. Mechanical stress increased both nuclear membrane ruptures and DNA damage, whereas minimizing transmission of cytoskeletal forces to the nucleus had the opposite effects.
Collapse
|
27
|
Krishnamoorthy V, Khanna R, Parnaik VK. E3 ubiquitin ligase HECW2 targets PCNA and lamin B1. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2018; 1865:1088-1104. [PMID: 29753763 DOI: 10.1016/j.bbamcr.2018.05.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2017] [Revised: 04/20/2018] [Accepted: 05/07/2018] [Indexed: 12/21/2022]
Abstract
Lamins constitute the major architectural proteins of the nuclear lamina that help in maintaining nuclear organization. Mutations in lamins are associated with diverse degenerative diseases, collectively termed laminopathies. HECW2, a HECT-type E3 ubiquitin ligase, is transcriptionally upregulated in HeLa cells expressing Emery-Dreifuss muscular dystrophy-causing-lamin A mutants. However, the role of HECW2 upregulation in mediating downstream effects in lamin mutant-expressing cells was previously unexplored. Here, we show that HECW2 interacts with two lamin A-binding proteins, proliferating cell nuclear antigen (PCNA), via a canonical PCNA-interacting protein (PIP) motif, and lamin B1. HECW2 mediates their ubiquitination and targets them for proteasomal degradation. Cells expressing lamin A mutants G232E and Q294P, in which HECW2 is upregulated, show increased proteasomal degradation of PCNA and lamin B1 most likely mediated by HECW2. Our findings establish HECW2 as an E3 ubiquitin ligase for PCNA and lamin B1 which regulates their levels in laminopathic cells. We also found that HECW2 interacts with wild-type lamin A and ubiquitinates it and this interaction is reduced in case of lamin mutants G232E and Q294P. Our findings suggest that interplay among HECW2, lamin A, PCNA, and lamin B1 determines their respective homeostatic levels in the cell and dysregulation of these interactions may contribute to the pathogenicity of laminopathies.
Collapse
Affiliation(s)
| | - Richa Khanna
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India
| | - Veena K Parnaik
- CSIR-Centre for Cellular and Molecular Biology, Hyderabad, India.
| |
Collapse
|
28
|
Sen Gupta A, Sengupta K. Lamin B2 Modulates Nucleolar Morphology, Dynamics, and Function. Mol Cell Biol 2017; 37:e00274-17. [PMID: 28993479 PMCID: PMC5705821 DOI: 10.1128/mcb.00274-17] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 07/05/2017] [Accepted: 09/29/2017] [Indexed: 01/11/2023] Open
Abstract
The nucleolus is required for ribosome biogenesis. Human cells have 2 or 3 nucleoli associated with nucleolar organizer region (NOR)-bearing chromosomes. An increase in number and altered nucleolar morphology define cancer cells. However, the mechanisms that modulate nucleolar morphology and function are unclear. Here we show that in addition to localizing at the nuclear envelope, lamin B2 localizes proximal to nucleolin at the granular component (GC) of the nucleolus and associates with the nucleolar proteins nucleolin and nucleophosmin. Lamin B2 knockdown severely disrupted the nucleolar morphology, which was rescued to intact and discrete nucleoli upon lamin B2 overexpression. Furthermore, two mutually exclusive lamin B2 deletion mutants, ΔHead and ΔSLS, rescued nuclear and nucleolar morphology defects, respectively, induced upon lamin B2 depletion, suggesting independent roles for lamin B2 at the nucleolus and nuclear envelope. Lamin B2 depletion increased nucleolin aggregation in the nucleoplasm, implicating lamin B2 in stabilizing nucleolin within the nucleolus. Lamin B2 knockdown upregulated nucleolus-specific 45S rRNA and upstream intergenic sequence (IGS) transcripts. The IGS transcripts colocalized with aggregates of nucleolin speckles, which were sustained in the nucleoplasm upon lamin B2 depletion. Taken together, these studies uncover a novel role for lamin B2 in modulating the morphology, dynamics, and function of the nucleolus.
Collapse
Affiliation(s)
- Ayantika Sen Gupta
- Biology, Indian Institute of Science Education and Research, Pune, India
| | - Kundan Sengupta
- Biology, Indian Institute of Science Education and Research, Pune, India
| |
Collapse
|
29
|
Abstract
Nuclear lamins are components of the peripheral lamina that define the mechanical properties of nuclei and tether heterochromatin to the periphery. A-type lamins localize also to the nuclear interior, but the regulation and specific functions of this nucleoplasmic lamin pool are poorly understood. In this Commentary, we summarize known pathways that are potentially involved in the localization and dynamic behavior of intranuclear lamins, including their post-translational modifications and interactions with nucleoplasmic proteins, such as lamina-associated polypeptide 2α (LAP2α; encoded by TMPO). In addition, new data suggest that lamins in the nuclear interior have an important role in chromatin regulation and gene expression through dynamic binding to both hetero- and euchromatic genomic regions and promoter subdomains, thereby affecting epigenetic pathways and chromatin accessibility. Nucleoplasmic lamins also have a role in spatial chromatin organization and may be involved in mechanosignaling. In view of this newly emerging concept, we propose that the previously reported cellular phenotypes in lamin-linked diseases are, at least in part, rooted in an impaired regulation and/or function of the nucleoplasmic lamin A/C pool.
Collapse
Affiliation(s)
- Nana Naetar
- Center of Medical Biochemistry, Max F. Perutz Laboratories (MFPL), Medical University of Vienna, Vienna Biocenter (VBC), Dr.-Bohr-Gasse 9, Vienna A-1030, Austria
| | - Simona Ferraioli
- Center of Medical Biochemistry, Max F. Perutz Laboratories (MFPL), Medical University of Vienna, Vienna Biocenter (VBC), Dr.-Bohr-Gasse 9, Vienna A-1030, Austria
| | - Roland Foisner
- Center of Medical Biochemistry, Max F. Perutz Laboratories (MFPL), Medical University of Vienna, Vienna Biocenter (VBC), Dr.-Bohr-Gasse 9, Vienna A-1030, Austria
| |
Collapse
|
30
|
Cobb AM, Murray TV, Warren DT, Liu Y, Shanahan CM. Disruption of PCNA-lamins A/C interactions by prelamin A induces DNA replication fork stalling. Nucleus 2017; 7:498-511. [PMID: 27676213 PMCID: PMC5120601 DOI: 10.1080/19491034.2016.1239685] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022] Open
Abstract
The accumulation of prelamin A is linked to disruption of cellular homeostasis, tissue degeneration and aging. Its expression is implicated in compromised genome stability and increased levels of DNA damage, but to date there is no complete explanation for how prelamin A exerts its toxic effects. As the nuclear lamina is important for DNA replication we wanted to investigate the relationship between prelamin A expression and DNA replication fork stability. In this study we report that the expression of prelamin A in U2OS cells induced both mono-ubiquitination of proliferating cell nuclear antigen (PCNA) and subsequent induction of Pol η, two hallmarks of DNA replication fork stalling. Immunofluorescence microscopy revealed that cells expressing prelamin A presented with high levels of colocalisation between PCNA and γH2AX, indicating collapse of stalled DNA replication forks into DNA double-strand breaks. Subsequent protein-protein interaction assays showed prelamin A interacted with PCNA and that its presence mitigated interactions between PCNA and the mature nuclear lamina. Thus, we propose that the cytotoxicity of prelamin A arises in part, from it actively competing against mature lamin A to bind PCNA and that this destabilises DNA replication to induce fork stalling which in turn contributes to genomic instability.
Collapse
Affiliation(s)
- Andrew M Cobb
- a King's College London , The James Black Center , London , United Kingdom
| | - Thomas V Murray
- a King's College London , The James Black Center , London , United Kingdom
| | - Derek T Warren
- a King's College London , The James Black Center , London , United Kingdom
| | - Yiwen Liu
- a King's College London , The James Black Center , London , United Kingdom
| | | |
Collapse
|
31
|
Dixon CR, Platani M, Makarov AA, Schirmer EC. Microinjection of Antibodies Targeting the Lamin A/C Histone-Binding Site Blocks Mitotic Entry and Reveals Separate Chromatin Interactions with HP1, CenpB and PML. Cells 2017; 6:cells6020009. [PMID: 28346356 PMCID: PMC5492013 DOI: 10.3390/cells6020009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Revised: 02/24/2017] [Accepted: 03/14/2017] [Indexed: 02/07/2023] Open
Abstract
Lamins form a scaffold lining the nucleus that binds chromatin and contributes to spatial genome organization; however, due to the many other functions of lamins, studies knocking out or altering the lamin polymer cannot clearly distinguish between direct and indirect effects. To overcome this obstacle, we specifically targeted the mapped histone-binding site of A/C lamins by microinjecting antibodies specific to this region predicting that this would make the genome more mobile. No increase in chromatin mobility was observed; however, interestingly, injected cells failed to go through mitosis, while control antibody-injected cells did. This effect was not due to crosslinking of the lamin polymer, as Fab fragments also blocked mitosis. The lack of genome mobility suggested other lamin-chromatin interactions. To determine what these might be, mini-lamin A constructs were expressed with or without the histone-binding site that assembled into independent intranuclear structures. HP1, CenpB and PML proteins accumulated at these structures for both constructs, indicating that other sites supporting chromatin interactions exist on lamin A. Together, these results indicate that lamin A-chromatin interactions are highly redundant and more diverse than generally acknowledged and highlight the importance of trying to experimentally separate their individual functions.
Collapse
Affiliation(s)
- Charles R Dixon
- The Wellcome Trust Centre for Cell Biology, University of Edinburgh, Kings Buildings, Swann 5.22, Max Born Crescent, Edinburgh EH9 3BF, UK.
| | - Melpomeni Platani
- The Wellcome Trust Centre for Cell Biology, University of Edinburgh, Kings Buildings, Swann 5.22, Max Born Crescent, Edinburgh EH9 3BF, UK.
| | - Alexandr A Makarov
- The Wellcome Trust Centre for Cell Biology, University of Edinburgh, Kings Buildings, Swann 5.22, Max Born Crescent, Edinburgh EH9 3BF, UK.
| | - Eric C Schirmer
- The Wellcome Trust Centre for Cell Biology, University of Edinburgh, Kings Buildings, Swann 5.22, Max Born Crescent, Edinburgh EH9 3BF, UK.
| |
Collapse
|
32
|
Ranade D, Koul S, Thompson J, Prasad KB, Sengupta K. Chromosomal aneuploidies induced upon Lamin B2 depletion are mislocalized in the interphase nucleus. Chromosoma 2017; 126:223-244. [PMID: 26921073 PMCID: PMC5371638 DOI: 10.1007/s00412-016-0580-y] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2015] [Revised: 01/28/2016] [Accepted: 02/09/2016] [Indexed: 12/31/2022]
Abstract
Chromosome territories assume non-random positions in the interphase nucleus with gene-rich chromosomes localized toward the nuclear interior and gene-poor chromosome territories toward the nuclear periphery. Lamins are intermediate filament proteins of the inner nuclear membrane required for the maintenance of nuclear structure and function. Here, we show using whole-genome expression profiling that Lamin A/C or Lamin B2 depletion in an otherwise diploid colorectal cancer cell line (DLD1) deregulates transcript levels from specific chromosomes. Further, three-dimensional fluorescence in situ hybridization (3D-FISH) analyses of a subset of these transcriptionally deregulated chromosome territories revealed that the diploid chromosome territories in Lamin-depleted cells largely maintain conserved positions in the interphase nucleus in a gene-density-dependent manner. In addition, chromosomal aneuploidies were induced in ~25 % of Lamin A/C or Lamin B2-depleted cells. Sub-populations of these aneuploid cells consistently showed a mislocalization of the gene-rich aneuploid chromosome 19 territory toward the nuclear periphery, while gene-poor aneuploid chromosome 18 territory was mislocalized toward the nuclear interior predominantly upon Lamin B2 than Lamin A/C depletion. In addition, a candidate gene locus ZNF570 (Chr.19q13.12) significantly overexpressed upon Lamin B2 depletion was remarkably repositioned away from the nuclear lamina. Taken together, our studies strongly implicate an overarching role for Lamin B2 in the maintenance of nuclear architecture since loss of Lamin B2 relieves the spatial positional constraints required for maintaining conserved localization of aneuploid chromosome territories in the interphase nucleus.
Collapse
Affiliation(s)
- Devika Ranade
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India
| | - Shivsmriti Koul
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India
| | - Joyce Thompson
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India
| | - Kumar Brajesh Prasad
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India
| | - Kundan Sengupta
- Biology, Indian Institute of Science Education and Research, Pune, Main Building, Homi Bhabha Road, Pashan, Pune, Maharashtra, 411008, India.
| |
Collapse
|
33
|
Graziano S, Gonzalo S. Mechanisms of oncogene-induced genomic instability. Biophys Chem 2016; 225:49-57. [PMID: 28073589 DOI: 10.1016/j.bpc.2016.11.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Revised: 11/17/2016] [Accepted: 11/18/2016] [Indexed: 01/08/2023]
Abstract
Activating mutations in oncogenes promote uncontrolled proliferation and malignant transformation. Approximately 30% of human cancers carry mutations in the RAS oncogene. Paradoxically, expression of mutant constitutively active Ras protein in primary human cells results in a premature proliferation arrest known as oncogene-induced senescence (OIS). This is more commonly observed in human pre-neoplasia than in neoplastic lesions, and is considered a tumor suppressor mechanism. Senescent cells are still metabolically active but in a status of cell cycle arrest characterized by specific morphological and physiological features that distinguish them from both proliferating cells, and cells growth-arrested by other means. Although the molecular mechanisms by which OIS is established are not totally understood, the current view is that OIS in human cells is tightly linked to persistent activation of the DNA damage response (DDR) pathway, as a consequence of replication stress. Here we will highlight recent advances in our understanding of molecular mechanisms leading to hyper-replication stress in response to oncogene activation, and of the crosstalk between replication stress and persistent activation of the DDR. We will also discuss new evidence for DNA repair deficiencies during OIS, which might increase the genomic instability that drives senescence bypass and malignant transformation.
Collapse
Affiliation(s)
- Simona Graziano
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO 63104, USA
| | - Susana Gonzalo
- Edward A. Doisy Department of Biochemistry and Molecular Biology, Saint Louis University School of Medicine, St. Louis, MO 63104, USA.
| |
Collapse
|
34
|
Abstract
Lamins are major components of the nuclear lamina, a network of proteins that supports the nuclear envelope in metazoan cells. Over the past decade, biochemical studies have provided support for the view that lamins are not passive bystanders providing mechanical stability to the nucleus but play an active role in the organization of the genome and the function of fundamental nuclear processes. It has also become apparent that lamins are critical for human health, as a large number of mutations identified in the gene that encodes for A-type lamins are associated with tissue-specific and systemic genetic diseases, including the accelerated aging disorder known as Hutchinson-Gilford progeria syndrome. Recent years have witnessed great advances in our understanding of the role of lamins in the nucleus and the functional consequences of disease-associated A-type lamin mutations. Many of these findings have been presented in comprehensive reviews. In this mini-review, we discuss recent breakthroughs in the role of lamins in health and disease and what lies ahead in lamin research.
Collapse
Affiliation(s)
- Sita Reddy
- Department of Biochemistry and Molecular Biology, Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Lucio Comai
- Department of Biochemistry and Molecular Biology, Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA; Department of Molecular Microbiology and Immunology, Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| |
Collapse
|
35
|
Abstract
The nucleus is typically depicted as a sphere encircled by a smooth surface of nuclear envelope. For most cell types, this depiction is accurate. In other cell types and in some pathological conditions, however, the smooth nuclear exterior is interrupted by tubular invaginations of the nuclear envelope, often referred to as a “nucleoplasmic reticulum,” into the deep nuclear interior. We have recently reported a significant expansion of the nucleoplasmic reticulum in postmortem human Alzheimer's disease brain tissue. We found that dysfunction of the nucleoskeleton, a lamin-rich meshwork that coats the inner nuclear membrane and associated invaginations, is causal for Alzheimer's disease-related neurodegeneration in vivo. Additionally, we demonstrated that proper function of the nucleoskeleton is required for survival of adult neurons and maintaining genomic architecture. Here, we elaborate on the significance of these findings in regard to pathological states and physiological aging, and discuss cellular causes and consequences of nuclear envelope invagination.
Collapse
Affiliation(s)
- Bess Frost
- a Barshop Institute for Longevity and Aging Studies , Department of Cellular and Structural Biology , University of Texas Health Science Center San Antonio , San Antonio , Texas , USA
| |
Collapse
|
36
|
Fu Y, Lv P, Yan G, Fan H, Cheng L, Zhang F, Dang Y, Wu H, Wen B. MacroH2A1 associates with nuclear lamina and maintains chromatin architecture in mouse liver cells. Sci Rep 2015; 5:17186. [PMID: 26603343 PMCID: PMC4658601 DOI: 10.1038/srep17186] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2015] [Accepted: 10/26/2015] [Indexed: 12/26/2022] Open
Abstract
In the interphase nucleus, chromatin is organized into three-dimensional conformation to coordinate genome functions. The lamina-chromatin association is important to facilitate higher-order chromatin in mammalian cells, but its biological significances and molecular mechanisms remain poorly understood. One obstacle is that the list of lamina-associated proteins remains limited, presumably due to the inherent insolubility of lamina proteins. In this report, we identified 182 proteins associated with lamin B1 (a constitutive component of lamina) in mouse hepatocytes, by adopting virus-based proximity-dependent biotin identification. These proteins are functionally related to biological processes such as chromatin organization. As an example, we validated the association between lamin B1 and core histone macroH2A1, a histone associated with repressive chromatin. Furthermore, we mapped Lamina-associated domains (LADs) in mouse liver cells and found that boundaries of LADs are enriched for macroH2A. More interestingly, knocking-down of macroH2A1 resulted in the release of heterochromatin foci marked by histone lysine 9 trimethylation (H3K9me3) and the decondensation of global chromatin structure. However, down-regulation of lamin B1 led to redistribution of macroH2A1. Taken together, our data indicated that macroH2A1 is associated with lamina and is required to maintain chromatin architecture in mouse liver cells.
Collapse
Affiliation(s)
- Yuhua Fu
- Key Laboratory of Molecular Medicine of Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Pin Lv
- Key Laboratory of Molecular Medicine of Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Guoquan Yan
- Key Laboratory of Molecular Medicine of Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
- Department of Chemistry, Fudan University, Shanghai, 200433
| | - Hui Fan
- Key Laboratory of Molecular Medicine of Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Lu Cheng
- Key Laboratory of Molecular Medicine of Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Feng Zhang
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| | - Yongjun Dang
- Key Laboratory of Molecular Medicine of Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
| | - Hao Wu
- Department of Biostatistics and Bioinformatics, Emory University, Atlanta, GA 30322, USA
| | - Bo Wen
- Key Laboratory of Molecular Medicine of Ministry of Education and Institutes of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai 200032, China
- State Key Laboratory of Genetic Engineering and Collaborative Innovation Center of Genetics and Development, School of Life Sciences, Fudan University, Shanghai 200438, China
| |
Collapse
|
37
|
Bercht Pfleghaar K, Taimen P, Butin-Israeli V, Shimi T, Langer-Freitag S, Markaki Y, Goldman AE, Wehnert M, Goldman RD. Gene-rich chromosomal regions are preferentially localized in the lamin B deficient nuclear blebs of atypical progeria cells. Nucleus 2015; 6:66-76. [PMID: 25738644 DOI: 10.1080/19491034.2015.1004256] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023] Open
Abstract
More than 20 mutations in the gene encoding A-type lamins (LMNA) cause progeria, a rare premature aging disorder. The major pathognomonic hallmarks of progeria cells are seen as nuclear deformations or blebs that are related to the redistribution of A- and B-type lamins within the nuclear lamina. However, the functional significance of these progeria-associated blebs remains unknown. We have carried out an analysis of the structural and functional consequences of progeria-associated nuclear blebs in dermal fibroblasts from a progeria patient carrying a rare point mutation p.S143F (C428T) in lamin A/C. These blebs form microdomains that are devoid of major structural components of the nuclear envelope (NE)/lamina including B-type lamins and nuclear pore complexes (NPCs) and are enriched in A-type lamins. Using laser capture microdissection and comparative genomic hybridization (CGH) analyses, we show that, while these domains are devoid of centromeric heterochromatin and gene-poor regions of chromosomes, they are enriched in gene-rich chromosomal regions. The active form of RNA polymerase II is also greatly enriched in blebs as well as nascent RNA but the nuclear co-activator SKIP is significantly reduced in blebs compared to other transcription factors. Our results suggest that the p.S143F progeria mutation has a severe impact not only on the structure of the lamina but also on the organization of interphase chromatin domains and transcription. These structural defects are likely to contribute to gene expression changes reported in progeria and other types of laminopathies.
Collapse
Affiliation(s)
- Katrin Bercht Pfleghaar
- a Department of Cell and Molecular Biology ; Feinberg School of Medicine; Northwestern University ; Chicago , IL USA
| | | | | | | | | | | | | | | | | |
Collapse
|
38
|
Abstract
DNA replication begins with the assembly of pre-replication complexes (pre-RCs) at thousands of DNA replication origins during the G1 phase of the cell cycle. At the G1-S-phase transition, pre-RCs are converted into pre-initiation complexes, in which the replicative helicase is activated, leading to DNA unwinding and initiation of DNA synthesis. However, only a subset of origins are activated during any S phase. Recent insights into the mechanisms underlying this choice reveal how flexibility in origin usage and temporal activation are linked to chromosome structure and organization, cell growth and differentiation, and replication stress.
Collapse
|
39
|
Butin-Israeli V, Adam SA, Jain N, Otte GL, Neems D, Wiesmüller L, Berger SL, Goldman RD. Role of lamin b1 in chromatin instability. Mol Cell Biol 2015; 35:884-98. [PMID: 25535332 PMCID: PMC4323489 DOI: 10.1128/mcb.01145-14] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Revised: 10/01/2014] [Accepted: 12/18/2014] [Indexed: 01/14/2023] Open
Abstract
Nuclear lamins play important roles in the organization and structure of the nucleus; however, the specific mechanisms linking lamin structure to nuclear functions are poorly defined. We demonstrate that reducing nuclear lamin B1 expression by short hairpin RNA-mediated silencing in cancer cell lines to approximately 50% of normal levels causes a delay in the cell cycle and accumulation of cells in early S phase. The S phase delay appears to be due to the stalling and collapse of replication forks. The double-strand DNA breaks resulting from replication fork collapse were inefficiently repaired, causing persistent DNA damage signaling and the assembly of extensive repair foci on chromatin. The expression of multiple factors involved in DNA replication and repair by both nonhomologous end joining and homologous repair is misregulated when lamin B1 levels are reduced. We further demonstrate that lamin B1 interacts directly with the promoters of some genes associated with DNA damage response and repair, including BRCA1 and RAD51. Taken together, the results suggest that the maintenance of lamin B1 levels is required for DNA replication and repair through regulation of the expression of key factors involved in these essential nuclear functions.
Collapse
Affiliation(s)
- Veronika Butin-Israeli
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Stephen A Adam
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Nikhil Jain
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Gabriel L Otte
- Epigenetics Program, Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Daniel Neems
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| | - Lisa Wiesmüller
- Department of Obstetrics and Gynecology, Ulm University, Ulm, Germany
| | - Shelly L Berger
- Epigenetics Program, Department of Cell and Developmental Biology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Robert D Goldman
- Department of Cell and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA
| |
Collapse
|
40
|
Gruenbaum Y, Medalia O. Lamins: the structure and protein complexes. Curr Opin Cell Biol 2015; 32:7-12. [DOI: 10.1016/j.ceb.2014.09.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 09/19/2014] [Accepted: 09/21/2014] [Indexed: 10/24/2022]
|
41
|
Camps J, Erdos MR, Ried T. The role of lamin B1 for the maintenance of nuclear structure and function. Nucleus 2015; 6:8-14. [PMID: 25602590 PMCID: PMC4615282 DOI: 10.1080/19491034.2014.1003510] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2014] [Revised: 11/24/2014] [Accepted: 11/25/2014] [Indexed: 12/22/2022] Open
Abstract
Lamins constitute an integral structural component of the nuclear lamina. However, their impact on the structure and stability of chromosome territories, and on the regulation of gene expression is explored to a lesser extent. By 3D-FISH, Camps and colleagues showed that lamin B1 (LMNB1) is required for proper chromosome condensation in interphase nuclei, and deficiency of LMNB1 triggers the relocation of the epigenetic mark of facultative heterochromatin, H3K27me3, toward the interior of the nucleus. Additionally, LMNB1 repression slowed cellular growth due to S-phase delays and increased genomic instability. Finally, silencing of LMNB1 resulted in enlarged nuclear speckles and in extensive changes in alternative splicing of multiple genes. Altogether, the data suggest a central role of LMNB1 for the condensation of chromosome territories, for the distribution of heterochromatin, and for the regulation of gene expression and splicing.
Collapse
Affiliation(s)
- Jordi Camps
- Laboratory of Gastrointestinal and Pancreatic Oncology; Institut d’Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS); Hospital Clínic of Barcelona, CIBERehd; Barcelona, Spain
| | - Michael R Erdos
- Genome Technology Branch; National Human Genome Research Institute; National Institutes of Health; Bethesda, MD USA
| | - Thomas Ried
- Section of Cancer Genomics, Genetics Branch; National Cancer Institute; National Institutes of Health; Bethesda, MD USA
| |
Collapse
|
42
|
Nuclear lamina remodelling and its implications for human disease. Cell Tissue Res 2014; 360:621-31. [DOI: 10.1007/s00441-014-2069-4] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 11/11/2014] [Indexed: 10/24/2022]
|
43
|
An absence of nuclear lamins in keratinocytes leads to ichthyosis, defective epidermal barrier function, and intrusion of nuclear membranes and endoplasmic reticulum into the nuclear chromatin. Mol Cell Biol 2014; 34:4534-44. [PMID: 25312645 DOI: 10.1128/mcb.00997-14] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
B-type lamins (lamins B1 and B2) have been considered to be essential for many crucial functions in the cell nucleus (e.g., DNA replication and mitotic spindle formation). However, this view has been challenged by the observation that an absence of both B-type lamins in keratinocytes had no effect on cell proliferation or the development of skin and hair. The latter findings raised the possibility that the functions of B-type lamins are subserved by lamins A and C. To explore that idea, we created mice lacking all nuclear lamins in keratinocytes. Those mice developed ichthyosis and a skin barrier defect, which led to death from dehydration within a few days after birth. Microscopy of nuclear-lamin-deficient skin revealed hyperkeratosis and a disordered stratum corneum with an accumulation of neutral lipid droplets; however, BrdU incorporation into keratinocytes was normal. Skin grafting experiments confirmed the stratum corneum abnormalities and normal BrdU uptake. Interestingly, the absence of nuclear lamins in keratinocytes resulted in an interspersion of nuclear/endoplasmic reticulum membranes with the chromatin. Thus, a key function of the nuclear lamina is to serve as a "fence" and prevent the incursion of cytoplasmic organelles into the nuclear chromatin.
Collapse
|
44
|
Camps J, Wangsa D, Falke M, Brown M, Case CM, Erdos MR, Ried T. Loss of lamin B1 results in prolongation of S phase and decondensation of chromosome territories. FASEB J 2014; 28:3423-34. [PMID: 24732130 PMCID: PMC4101663 DOI: 10.1096/fj.14-250456] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 04/07/2014] [Indexed: 01/04/2023]
Abstract
Nuclear lamin B1 (LMNB1) constitutes one of the major structural proteins in the lamina mesh. We silenced the expression of LMNB1 by RNA interference in the colon cancer cell line DLD-1 and showed a dramatic redistribution of H3K27me3 from the periphery to a more homogeneous nuclear dispersion. In addition, we observed telomere attrition and an increased frequency of micronuclei and nuclear blebs. By 3D-FISH analyses, we demonstrated that the volume and surface of chromosome territories were significantly larger in LMNB1-depleted cells, suggesting that LMNB1 is required to maintain chromatin condensation in interphase nuclei. These changes led to a prolonged S phase due to activation of Chk1. Finally, silencing of LMNB1 resulted in extensive changes in alternative splicing of multiple genes and in a higher number of enlarged nuclear speckles. Taken together, our results suggest a mechanistic role of the nuclear lamina in the organization of chromosome territories, maintenance of genome integrity and proper gene splicing.
Collapse
Affiliation(s)
- Jordi Camps
- Section of Cancer Genomics, Genetics Branch, National Cancer Institute, and
| | - Darawalee Wangsa
- Section of Cancer Genomics, Genetics Branch, National Cancer Institute, and
| | - Martin Falke
- Section of Cancer Genomics, Genetics Branch, National Cancer Institute, and
| | - Markus Brown
- Section of Cancer Genomics, Genetics Branch, National Cancer Institute, and
| | - Chanelle M Case
- Section of Cancer Genomics, Genetics Branch, National Cancer Institute, and
| | - Michael R Erdos
- Genome Technology Branch, National Human Genome Research Institute, U.S. National Institutes of Health, Bethesda, Maryland, USA
| | - Thomas Ried
- Section of Cancer Genomics, Genetics Branch, National Cancer Institute, and
| |
Collapse
|
45
|
Lee JM, Jung HJ, Fong LG, Young SG. Do lamin B1 and lamin B2 have redundant functions? Nucleus 2014; 5:287-92. [PMID: 25482116 PMCID: PMC4152341 DOI: 10.4161/nucl.29615] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 06/12/2014] [Accepted: 06/16/2014] [Indexed: 12/29/2022] Open
Abstract
Lamins B1 and B2 have a high degree of sequence similarity and are widely expressed from the earliest stages of development. Studies of Lmnb1 and Lmnb2 knockout mice revealed that both of the B-type lamins are crucial for neuronal migration in the developing brain. These observations naturally posed the question of whether the two B-type lamins might play redundant functions in the development of the brain. To explore that issue, Lee and coworkers generated "reciprocal knock-in mice" (knock-in mice that produce lamin B1 from the Lmnb2 locus and knock-in mice that produce lamin B2 from the Lmnb1 locus). Both lines of knock-in mice manifested neurodevelopmental abnormalities similar to those in conventional knockout mice, indicating that lamins B1 and B2 have unique functions and that increased production of one B-type lamin cannot compensate for the loss of the other.
Collapse
Affiliation(s)
- John M Lee
- Department of Medicine; David Geffen School of Medicine; University of California; Los Angeles, CA USA
| | - Hea-Jin Jung
- Molecular Biology Institute; University of California; Los Angeles, CA USA
| | - Loren G Fong
- Department of Medicine; David Geffen School of Medicine; University of California; Los Angeles, CA USA
| | - Stephen G Young
- Department of Medicine; David Geffen School of Medicine; University of California; Los Angeles, CA USA
- Molecular Biology Institute; University of California; Los Angeles, CA USA
- Department of Human Genetics; David Geffen School of Medicine; University of California; Los Angeles, CA USA
| |
Collapse
|
46
|
Kiel T, Busch A, Meyer-Rachner A, Hübner S. Laminopathy-inducing mutations reduce nuclear import of expressed prelamin A. Int J Biochem Cell Biol 2014; 53:271-80. [PMID: 24943589 DOI: 10.1016/j.biocel.2014.05.035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 05/20/2014] [Accepted: 05/26/2014] [Indexed: 01/07/2023]
Abstract
Lamins are structural components of the nuclear lamina and integral parts of the nucleoplasm. The tripartite domain structure partitions the molecule into an amino-terminal head, central rod and a carboxy-terminal tail domain. The tail domain contains a nuclear localization sequence and in most lamins an additional CaaX motif, which is necessary to post-translationally process prelamin to mature lamin. As players of nuclear and cellular integrity, lamins must possess unrestrained access to the nucleus. To study whether nuclear trafficking of lamins is compromised in laminopathies, we determined relative nuclear import activities between expressed prelamin A and selected laminopathy-inducing mutants thereof. Furthermore, the impact of inhibition of maturation on nuclear import of expressed prelamin A was examined. To perform quantitative transport measurements, import competent but lamina incorporation-deficient GFP- or DsRed-tagged prelamin A deletion mutants were used, which lacked the head and rod domain (ΔHR-prelamin A). Nuclear accumulation of ΔHR-prelamin A carrying the lipodystrophy and metabolic syndrome-inducing mutations R419C and L421P or progeria-causing deletions was significantly reduced, but that of the maturation-deficient mutant ΔHR-prelamin A SSIM was significantly increased. In the case of the full length prelamin A mutants R419C and L421P altered subcellular localization and reduced lamina incorporation were detected, with the prelamin A-binding protein Narf being redistributed into R419-containing aggregates. The results suggest that impaired nuclear transport of certain prelamin A mutants may represent a contributing factor in the pathogenesis of certain laminopathies.
Collapse
Affiliation(s)
- T Kiel
- Julius-Maximilians-University of Würzburg, Institute of Anatomy and Cell Biology, Würzburg, Germany
| | - A Busch
- Julius-Maximilians-University of Würzburg, Institute of Anatomy and Cell Biology, Würzburg, Germany
| | - A Meyer-Rachner
- Julius-Maximilians-University of Würzburg, Institute of Anatomy and Cell Biology, Würzburg, Germany
| | - S Hübner
- Julius-Maximilians-University of Würzburg, Institute of Anatomy and Cell Biology, Würzburg, Germany.
| |
Collapse
|
47
|
Wong X, Luperchio TR, Reddy KL. NET gains and losses: the role of changing nuclear envelope proteomes in genome regulation. Curr Opin Cell Biol 2014; 28:105-20. [PMID: 24886773 DOI: 10.1016/j.ceb.2014.04.005] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2014] [Revised: 03/21/2014] [Accepted: 04/11/2014] [Indexed: 01/13/2023]
Abstract
In recent years, our view of the nucleus has changed considerably with an increased awareness of the roles dynamic higher order chromatin structure and nuclear organization play in nuclear function. More recently, proteomics approaches have identified differential expression of nuclear lamina and nuclear envelope transmembrane (NET) proteins. Many NETs have been implicated in a range of developmental disorders as well as cell-type specific biological processes, including genome organization and nuclear morphology. While further studies are needed, it is clear that the differential nuclear envelope proteome contributes to cell-type specific nuclear identity and functions. This review discusses the importance of proteome diversity at the nuclear periphery and highlights the putative roles of NET proteins, with a focus on nuclear architecture.
Collapse
Affiliation(s)
- Xianrong Wong
- Johns Hopkins University, School of Medicine, Department of Biological Chemistry and Center for Epigenetics, 855N. Wolfe St., Rangos 574, Baltimore, MD 21044, United States
| | - Teresa R Luperchio
- Johns Hopkins University, School of Medicine, Department of Biological Chemistry and Center for Epigenetics, 855N. Wolfe St., Rangos 574, Baltimore, MD 21044, United States
| | - Karen L Reddy
- Johns Hopkins University, School of Medicine, Department of Biological Chemistry and Center for Epigenetics, 855N. Wolfe St., Rangos 574, Baltimore, MD 21044, United States.
| |
Collapse
|
48
|
Abstract
Much of the work on nuclear lamins during the past 15 years has focused on mutations in LMNA (the gene for prelamin A and lamin C) that cause particular muscular dystrophy, cardiomyopathy, partial lipodystrophy, and progeroid syndromes. These disorders, often called "laminopathies," mainly affect mesenchymal tissues (e.g., striated muscle, bone, and fibrous tissue). Recently, however, a series of papers have identified important roles for nuclear lamins in the central nervous system. Studies of knockout mice uncovered a key role for B-type lamins (lamins B1 and B2) in neuronal migration in the developing brain. Also, duplications of LMNB1 (the gene for lamin B1) have been shown to cause autosome-dominant leukodystrophy. Finally, recent studies have uncovered a peculiar pattern of nuclear lamin expression in the brain. Lamin C transcripts are present at high levels in the brain, but prelamin A expression levels are very low-due to regulation of prelamin A transcripts by microRNA 9. This form of prelamin A regulation likely explains why "prelamin A diseases" such as Hutchinson-Gilford progeria syndrome spare the central nervous system. In this review, we summarize recent progress in elucidating links between nuclear lamins and neurobiology.
Collapse
|
49
|
Lee JM, Tu Y, Tatar A, Wu D, Nobumori C, Jung HJ, Yoshinaga Y, Coffinier C, de Jong PJ, Fong LG, Young SG. Reciprocal knock-in mice to investigate the functional redundancy of lamin B1 and lamin B2. Mol Biol Cell 2014; 25:1666-75. [PMID: 24672053 PMCID: PMC4019497 DOI: 10.1091/mbc.e14-01-0683] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2014] [Revised: 03/14/2014] [Accepted: 03/14/2014] [Indexed: 11/17/2022] Open
Abstract
Lamins B1 and B2 (B-type lamins) have very similar sequences and are expressed ubiquitously. In addition, both Lmnb1- and Lmnb2-deficient mice die soon after birth with neuronal layering abnormalities in the cerebral cortex, a consequence of defective neuronal migration. The similarities in amino acid sequences, expression patterns, and knockout phenotypes raise the question of whether the two proteins have redundant functions. To investigate this topic, we generated "reciprocal knock-in mice"-mice that make lamin B2 from the Lmnb1 locus (Lmnb1(B2/B2)) and mice that make lamin B1 from the Lmnb2 locus (Lmnb2(B1/B1)). Lmnb1(B2/B2) mice produced increased amounts of lamin B2 but no lamin B1; they died soon after birth with neuronal layering abnormalities in the cerebral cortex. However, the defects in Lmnb1(B2/B2) mice were less severe than those in Lmnb1-knockout mice, indicating that increased amounts of lamin B2 partially ameliorate the abnormalities associated with lamin B1 deficiency. Similarly, increased amounts of lamin B1 in Lmnb2(B1/B1) mice did not prevent the neurodevelopmental defects elicited by lamin B2 deficiency. We conclude that lamins B1 and B2 have unique roles in the developing brain and that increased production of one B-type lamin does not fully complement loss of the other.
Collapse
Affiliation(s)
- John M Lee
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Yiping Tu
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Angelica Tatar
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Daniel Wu
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Chika Nobumori
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Hea-Jin Jung
- Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095
| | - Yuko Yoshinaga
- Children's Hospital Oakland Research Institute, Oakland, CA 94609
| | - Catherine Coffinier
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Pieter J de Jong
- Children's Hospital Oakland Research Institute, Oakland, CA 94609
| | - Loren G Fong
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095
| | - Stephen G Young
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA 90095Molecular Biology Institute, University of California, Los Angeles, Los Angeles, CA 90095Department of Human Genetics, University of California, Los Angeles, Los Angeles, CA 90095
| |
Collapse
|
50
|
Kochin V, Shimi T, Torvaldson E, Adam SA, Goldman A, Pack CG, Melo-Cardenas J, Imanishi SY, Goldman RD, Eriksson JE. Interphase phosphorylation of lamin A. J Cell Sci 2014; 127:2683-96. [PMID: 24741066 DOI: 10.1242/jcs.141820] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Nuclear lamins form the major structural elements that comprise the nuclear lamina. Loss of nuclear structural integrity has been implicated as a key factor in the lamin A/C gene mutations that cause laminopathies, whereas the normal regulation of lamin A assembly and organization in interphase cells is still undefined. We assumed phosphorylation to be a major determinant, identifying 20 prime interphase phosphorylation sites, of which eight were high-turnover sites. We examined the roles of these latter sites by site-directed mutagenesis, followed by detailed microscopic analysis - including fluorescence recovery after photobleaching, fluorescence correlation spectroscopy and nuclear extraction techniques. The results reveal three phosphorylation regions, each with dominant sites, together controlling lamin A structure and dynamics. Interestingly, two of these interphase sites are hyper-phosphorylated in mitotic cells and one of these sites is within the sequence that is missing in progerin of the Hutchinson-Gilford progeria syndrome. We present a model where different phosphorylation combinations yield markedly different effects on the assembly, subunit turnover and the mobility of lamin A between, and within, the lamina, the nucleoplasm and the cytoplasm of interphase cells.
Collapse
Affiliation(s)
- Vitaly Kochin
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, FIN-20521 Turku, Finland Department of Biosciences, Åbo Akademi University, FIN-20520 Turku, Finland Department of Pathology, Sapporo Medical University, Sapporo, Hokkaido 060-8556, Japan
| | - Takeshi Shimi
- Northwestern University Feinberg School of Medicine, Department of Cell and Molecular Biology, Chicago, IL 60611, USA
| | - Elin Torvaldson
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, FIN-20521 Turku, Finland Department of Biosciences, Åbo Akademi University, FIN-20520 Turku, Finland
| | - Stephen A Adam
- Northwestern University Feinberg School of Medicine, Department of Cell and Molecular Biology, Chicago, IL 60611, USA
| | - Anne Goldman
- Northwestern University Feinberg School of Medicine, Department of Cell and Molecular Biology, Chicago, IL 60611, USA
| | - Chan-Gi Pack
- Cellular Informatics Laboratory, RIKEN, Wako-shi, Saitama 351-0198, Japan
| | - Johanna Melo-Cardenas
- Northwestern University Feinberg School of Medicine, Department of Cell and Molecular Biology, Chicago, IL 60611, USA
| | - Susumu Y Imanishi
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, FIN-20521 Turku, Finland
| | - Robert D Goldman
- Northwestern University Feinberg School of Medicine, Department of Cell and Molecular Biology, Chicago, IL 60611, USA
| | - John E Eriksson
- Turku Centre for Biotechnology, University of Turku and Åbo Akademi University, FIN-20521 Turku, Finland Department of Biosciences, Åbo Akademi University, FIN-20520 Turku, Finland
| |
Collapse
|