1
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Sandoval A, Garrido E, Camacho J, Magaña JJ, Cisneros B. Altered expression and localization of nuclear envelope proteins in a prostate cancer cell system. Mol Biol Rep 2024; 51:898. [PMID: 39115711 PMCID: PMC11310284 DOI: 10.1007/s11033-024-09836-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Accepted: 07/31/2024] [Indexed: 08/11/2024]
Abstract
BACKGROUND The nuclear envelope (NE), which is composed of the outer and inner nuclear membranes, the nuclear pore complex and the nuclear lamina, regulates a plethora of cellular processes, including those that restrict cancer development (genomic stability, cell cycle regulation, and cell migration). Thus, impaired NE is functionally related to tumorigenesis, and monitoring of NE alterations is used to diagnose cancer. However, the chronology of NE changes occurring during cancer evolution and the connection between them remained to be precisely defined, due to the lack of appropriate cell models. METHODS The expression and subcellular localization of NE proteins (lamins A/C and B1 and the inner nuclear membrane proteins emerin and β-dystroglycan [β-DG]) during prostate cancer progression were analyzed, using confocal microscopy and western blot assays, and a prostate cancer cell system comprising RWPE-1 epithelial prostate cells and several prostate cancer cell lines with different invasiveness. RESULTS Deformed nuclei and the mislocalization and low expression of lamin A/C, lamin B1, and emerin became more prominent as the invasiveness of the prostate cancer lines increased. Suppression of lamin A/C expression was an early event during prostate cancer evolution, while a more extensive deregulation of NE proteins, including β-DG, occurred in metastatic prostate cells. CONCLUSIONS The RWPE-1 cell line-based system was found to be suitable for the correlation of NE impairment with prostate cancer invasiveness and determination of the chronology of NE alterations during prostate carcinogenesis. Further study of this cell system would help to identify biomarkers for prostate cancer prognosis and diagnosis.
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Affiliation(s)
- Ariana Sandoval
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Ciudad de México, 07360, México
| | - Efrain Garrido
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Ciudad de México, 07360, México
| | - Javier Camacho
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados (CINVESTAV), Ciudad de México, 07360, México
| | - Jonathan Javier Magaña
- Laboratorio de Medicina Genómica, Departamento de Genética (CENIAQ), Instituto Nacional de Rehabilitación-Luis Guillermo Ibarra Ibarra (INR-LGII), Ciudad de México, 14389, México
- Departamento de Bioingeniería, Escuela de Ingeniería y Ciencias, Tecnologico de Monterrey, Campus Ciudad de México, 14380, México
| | - Bulmaro Cisneros
- Departamento de Genética y Biología Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional (CINVESTAV), Ciudad de México, 07360, México.
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2
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Neri I, Ramazzotti G, Mongiorgi S, Rusciano I, Bugiani M, Conti L, Cousin M, Giorgio E, Padiath QS, Vaula G, Cortelli P, Manzoli L, Ratti S. Understanding the Ultra-Rare Disease Autosomal Dominant Leukodystrophy: an Updated Review on Morpho-Functional Alterations Found in Experimental Models. Mol Neurobiol 2023; 60:6362-6372. [PMID: 37450245 PMCID: PMC10533580 DOI: 10.1007/s12035-023-03461-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2022] [Accepted: 06/22/2023] [Indexed: 07/18/2023]
Abstract
Autosomal dominant leukodystrophy (ADLD) is an ultra-rare, slowly progressive, and fatal neurodegenerative disorder associated with the loss of white matter in the central nervous system (CNS). Several years after its first clinical description, ADLD was found to be caused by coding and non-coding variants in the LMNB1 gene that cause its overexpression in at least the brain of patients. LMNB1 encodes for Lamin B1, a protein of the nuclear lamina. Lamin B1 regulates many cellular processes such as DNA replication, chromatin organization, and senescence. However, its functions have not been fully characterized yet. Nevertheless, Lamin B1 together with the other lamins that constitute the nuclear lamina has firstly the key role of maintaining the nuclear structure. Being the nucleus a dynamic system subject to both biochemical and mechanical regulation, it is conceivable that changes to its structural homeostasis might translate into functional alterations. Under this light, this review aims at describing the pieces of evidence that to date have been obtained regarding the effects of LMNB1 overexpression on cellular morphology and functionality. Moreover, we suggest that further investigation on ADLD morpho-functional consequences is essential to better understand this complex disease and, possibly, other neurological disorders affecting CNS myelination.
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Affiliation(s)
- Irene Neri
- Cellular Signalling Laboratory, Anatomy Centre, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126, Bologna, Italy
| | - Giulia Ramazzotti
- Cellular Signalling Laboratory, Anatomy Centre, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126, Bologna, Italy
| | - Sara Mongiorgi
- Cellular Signalling Laboratory, Anatomy Centre, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126, Bologna, Italy
| | - Isabella Rusciano
- Cellular Signalling Laboratory, Anatomy Centre, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126, Bologna, Italy
| | - Marianna Bugiani
- Department of Pathology, Amsterdam University Medical Centers, Vrije Universiteit and Amsterdam Neuroscience, 1105, Amsterdam, The Netherlands
| | - Luciano Conti
- Department of Cellular, Computational, and Integrative Biology (CIBIO), Università Degli Studi Di Trento, 38123, Povo-Trento, Italy
| | - Margot Cousin
- Center for Individualized Medicine and Department of Clinical Genomics, Mayo Clinic, Rochester, MN, 55905, USA
| | - Elisa Giorgio
- Department of Molecular Medicine, University of Pavia, 27100, Pavia, Italy
- Medical Genetics Unit, IRCCS Mondino Foundation, 27100, Pavia, Italy
| | - Quasar S Padiath
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, 15261, USA
| | - Giovanna Vaula
- Department of Neuroscience, Azienda Ospedaliera-Universitaria Città della Salute e della Scienza, 10126, Turin, Italy
| | - Pietro Cortelli
- IRCCS, Istituto Di Scienze Neurologiche Di Bologna, 40139, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126 , Bologna, Italy
| | - Lucia Manzoli
- Cellular Signalling Laboratory, Anatomy Centre, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126, Bologna, Italy
| | - Stefano Ratti
- Cellular Signalling Laboratory, Anatomy Centre, Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126, Bologna, Italy.
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3
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Buxboim A, Kronenberg-Tenga R, Salajkova S, Avidan N, Shahak H, Thurston A, Medalia O. Scaffold, mechanics and functions of nuclear lamins. FEBS Lett 2023; 597:2791-2805. [PMID: 37813648 DOI: 10.1002/1873-3468.14750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2023] [Revised: 09/05/2023] [Accepted: 09/26/2023] [Indexed: 10/11/2023]
Abstract
Nuclear lamins are type-V intermediate filaments that are involved in many nuclear processes. In mammals, A- and B-type lamins assemble into separate physical meshwork underneath the inner nuclear membrane, the nuclear lamina, with some residual fraction localized within the nucleoplasm. Lamins are the major part of the nucleoskeleton, providing mechanical strength and flexibility to protect the genome and allow nuclear deformability, while also contributing to gene regulation via interactions with chromatin. While lamins are the evolutionary ancestors of all intermediate filament family proteins, their ultimate filamentous assembly is markedly different from their cytoplasmic counterparts. Interestingly, hundreds of genetic mutations in the lamina proteins have been causally linked with a broad range of human pathologies, termed laminopathies. These include muscular, neurological and metabolic disorders, as well as premature aging diseases. Recent technological advances have contributed to resolving the filamentous structure of lamins and the corresponding lamina organization. In this review, we revisit the multiscale lamin organization and discuss its implications on nuclear mechanics and chromatin organization within lamina-associated domains.
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Affiliation(s)
- Amnon Buxboim
- The Rachel and Selim Benin School of Computer Science and Engineering and The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Israel
| | | | - Sarka Salajkova
- Department of Biochemistry, University of Zurich, Switzerland
| | - Nili Avidan
- The Rachel and Selim Benin School of Computer Science and Engineering and The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Israel
| | - Hen Shahak
- The Rachel and Selim Benin School of Computer Science and Engineering and The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Israel
| | - Alice Thurston
- Department of Biochemistry, University of Zurich, Switzerland
| | - Ohad Medalia
- Department of Biochemistry, University of Zurich, Switzerland
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4
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Xiao C, Liu J, Yang C, Zhai X, Liu P, Xiao X, Yu M. The Clinical Characteristics and Potential Molecular Mechanism of LMNA Mutation-Related Lipodystrophy. Adv Biol (Weinh) 2023; 7:e2200301. [PMID: 37303127 DOI: 10.1002/adbi.202200301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 05/03/2023] [Indexed: 06/13/2023]
Abstract
This study aimed to enhance understanding of LMNA mutation-related lipodystrophy by elucidating genotype-phenotype correlations and potential molecular mechanisms. Clinical data from six patients with LMNA mutation-related lipodystrophy are analyzed, and four distinct LMNA mutations are identified. Associations between mutations and lipodystrophy phenotypes are assessed. Three LMNA mutation plasmids are constructed and transfected into HEK293 cells. Protein stability, degradation pathways, and binding proteins of mutant Lamin A/C are examined using Western blotting, co-immunoprecipitation, and mass spectrometry. Confocal microscopy is employed to observe nuclear structure. Four different LMNA mutations are identified in the six patients, all exhibiting lipodystrophy and metabolic disorders. Cardiac dysfunction is observed in two out of six patients. Metformin and pioglitazone are the primary treatments for glucose control. Confocal microscopy revealed nuclear blebbing and irregular cell membranes. Mutant Lamin A/C stability is significantly decreased, and degradation occurred primarily via the ubiquitin-proteasome system (UPS). Potential binding ubiquitination-related proteins of mutant Lamin A/C are identified. This study investigated LMNA mutation-related lipodystrophy, identifying four unique mutations and their connections to specific phenotypes. It is found to decreased mutant Lamin A/C stability and degradation primarily through the UPS, offering new insights into molecular mechanisms and potential therapeutic targets.
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Affiliation(s)
- Cheng Xiao
- Department of Endocrinology, Key Laboratory of Endocrinology, National Health Commission, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Jieying Liu
- Department of Endocrinology, Key Laboratory of Endocrinology, National Health Commission, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
- Department of Medical Research Center, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Chunru Yang
- Department of Endocrinology, Key Laboratory of Endocrinology, National Health Commission, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Xiaojun Zhai
- Department of Endocrinology, Key Laboratory of Endocrinology, National Health Commission, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Peng Liu
- Department of Medical Research Center, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Xinhua Xiao
- Department of Endocrinology, Key Laboratory of Endocrinology, National Health Commission, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Miao Yu
- Department of Endocrinology, Key Laboratory of Endocrinology, National Health Commission, Peking Union Medical College Hospital, Peking Union Medical College, Chinese Academy of Medical Sciences, Beijing, 100730, China
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5
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Ghosh S, Isma J, Mazzeo L, Toniolo A, Simon C, Dotto GP. Nuclear lamin A/C phosphorylation by loss of Androgen Receptor is a global determinant of cancer-associated fibroblast activation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.28.546870. [PMID: 37425957 PMCID: PMC10327063 DOI: 10.1101/2023.06.28.546870] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/11/2023]
Abstract
Alterations of nuclear structure and function, and associated impact on gene transcription, are a hallmark of cancer cells. Little is known of these alterations in Cancer-Associated Fibroblasts (CAFs), a key component of the tumor stroma. Here we show that loss of androgen receptor (AR), which triggers early steps of CAF activation in human dermal fibroblasts (HDFs), leads to nuclear membrane alterations and increased micronuclei formation, which are unlinked from induction of cellular senescence. Similar alterations occur in fully established CAFs, which are overcome by restored AR function. AR associates with nuclear lamin A/C and loss of AR results in a substantially increased lamin A/C nucleoplasmic redistribution. Mechanistically, AR functions as a bridge between lamin A/C with the protein phosphatase PPP1. In parallel with a decreased lamin-PPP1 association, AR loss results in a marked increase of lamin A/C phosphorylation at Ser 301, which is also a feature of CAFs. Phosphorylated lamin A/C at Ser 301 binds to the transcription promoter regulatory region of several CAF effector genes, which are upregulated due to the loss of AR. More directly, expression of a lamin A/C Ser301 phosphomimetic mutant alone is sufficient to convert normal fibroblasts into tumor-promoting CAFs of the myofibroblast subtype, without an impact on senescence. These findings highlight the pivotal role of the AR-lamin A/C-PPP1 axis and lamin A/C phosphorylation at Ser 301 in driving CAF activation.
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Affiliation(s)
- Soumitra Ghosh
- Personalised Cancer Prevention Unit, ORL service, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
- Department of Immunobiology, University of Lausanne, Epalinges, Switzerland
| | - Jovan Isma
- Department of Immunobiology, University of Lausanne, Epalinges, Switzerland
| | - Luigi Mazzeo
- Department of Immunobiology, University of Lausanne, Epalinges, Switzerland
| | - Annagiada Toniolo
- Department of Immunobiology, University of Lausanne, Epalinges, Switzerland
| | - Christian Simon
- Personalised Cancer Prevention Unit, ORL service, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
- International Cancer Prevention Institute, Epalinges, Switzerland
| | - G. Paolo Dotto
- Personalised Cancer Prevention Unit, ORL service, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
- Department of Immunobiology, University of Lausanne, Epalinges, Switzerland
- Cutaneous Biology Research Center, Department of Dermatology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA
- International Cancer Prevention Institute, Epalinges, Switzerland
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6
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Abstract
In this chapter, we highlight examples of the diverse array of developmental, cellular, and biochemical insights that can be gained by using Drosophila melanogaster oogenesis as a model tissue. We begin with an overview of ovary development and adult oogenesis. Then we summarize how the adult Drosophila ovary continues to advance our understanding of stem cells, cell cycle, cell migration, cytoplasmic streaming, nurse cell dumping, and cell death. We also review emerging areas of study, including the roles of lipid droplets, ribosomes, and nuclear actin in egg development. Finally, we conclude by discussing the growing conservation of processes and signaling pathways that regulate oogenesis and female reproduction from flies to humans.
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7
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Duan T, Rodriguez-Tirado F, Geyer PK. Immunohistochemical Analysis of Nuclear Lamina Structures in the Drosophila Ovary Using CRISPR-Tagged Genes. Methods Mol Biol 2023; 2626:109-134. [PMID: 36715902 DOI: 10.1007/978-1-0716-2970-3_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The Drosophila ovary represents an outstanding model for investigating tissue homeostasis. Females continuously produce oocytes throughout their lifetime. However, as females age, fecundity declines, in part, due to changes in ovarian niche function and germline stem cell (GSC) homeostasis. Understanding the dynamics of GSC maintenance will provide needed insights into how coordinated tissue homeostasis is lost during aging. Critical regulators of GSC maintenance are proteins that reside in the nuclear lamina (NL), including the NL proteins emerin and Barrier-to-Autointegration Factor (BAF). Continued investigation of how emerin, BAF, and other NL proteins contribute to GSC function depends upon the availability of antibodies for NL proteins, a limiting resource. In this chapter, we discuss strategies for using clustered regularly interspaced short palindromic repeats (CRISPR) genomic editing to produce endogenously tagged NL genes to circumvent this obstacle, using the generation of the gfp-baf allele as an example. We describe strategies for validation of tagged alleles. Finally, we outline methods for immunohistochemical analysis of resulting tagged-NL proteins.
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Affiliation(s)
- Tingting Duan
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Felipe Rodriguez-Tirado
- Department of Biochemistry and Department of Molecular Physiology and Biophysics, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Pamela K Geyer
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
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8
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Wang C, Wojtynek M, Medalia O. Structural investigation of eukaryotic cells: From the periphery to the interior by cryo-electron tomography. Adv Biol Regul 2023; 87:100923. [PMID: 36280452 DOI: 10.1016/j.jbior.2022.100923] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 10/05/2022] [Accepted: 10/10/2022] [Indexed: 11/06/2022]
Abstract
Cryo-electron tomography (cryo-ET) combines a close-to-life preservation of the cell with high-resolution three-dimensional (3D) imaging. This allows to study the molecular architecture of the cellular landscape and provides unprecedented views on biological processes and structures. In this review we mainly focus on the application of cryo-ET to visualize and structurally characterize eukaryotic cells - from the periphery to the cellular interior. We discuss strategies that can be employed to investigate the structure of challenging targets in their cellular environment as well as the application of complimentary approaches in conjunction with cryo-ET.
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Affiliation(s)
- Chunyang Wang
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Matthias Wojtynek
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Ohad Medalia
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
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9
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Stiekema M, Houben F, Verheyen F, Borgers M, Menzel J, Meschkat M, van Zandvoort MAMJ, Ramaekers FCS, Broers JLV. The Role of Lamins in the Nucleoplasmic Reticulum, a Pleiomorphic Organelle That Enhances Nucleo-Cytoplasmic Interplay. Front Cell Dev Biol 2022; 10:914286. [PMID: 35784476 PMCID: PMC9243388 DOI: 10.3389/fcell.2022.914286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 05/24/2022] [Indexed: 12/15/2022] Open
Abstract
Invaginations of the nuclear membrane occur in different shapes, sizes, and compositions. Part of these pleiomorphic invaginations make up the nucleoplasmic reticulum (NR), while others are merely nuclear folds. We define the NR as tubular invaginations consisting of either both the inner and outer nuclear membrane, or only the inner nuclear membrane. Specifically, invaginations of both the inner and outer nuclear membrane are also called type II NR, while those of only the inner nuclear membrane are defined as type I NR. The formation and structure of the NR is determined by proteins associated to the nuclear membrane, which induce a high membrane curvature leading to tubular invaginations. Here we review and discuss the current knowledge of nuclear invaginations and the NR in particular. An increase in tubular invaginations of the nuclear envelope is associated with several pathologies, such as laminopathies, cancer, (reversible) heart failure, and Alzheimer’s disease. Furthermore, viruses can induce both type I and II NR. In laminopathies, the amount of A-type lamins throughout the nucleus is generally decreased or the organization of lamins or lamin-associated proteins is disturbed. Also, lamin overexpression or modulation of lamin farnesylation status impacts NR formation, confirming the importance of lamin processing in NR formation. Virus infections reorganize the nuclear lamina via (de)phosphorylation of lamins, leading to an uneven thickness of the nuclear lamina and in turn lobulation of the nuclear membrane and the formation of invaginations of the inner nuclear membrane. Since most studies on the NR have been performed with cell cultures, we present additional proof for the existence of these structures in vivo, focusing on a variety of differentiated cardiovascular and hematopoietic cells. Furthermore, we substantiate the knowledge of the lamin composition of the NR by super-resolution images of the lamin A/C and B1 organization. Finally, we further highlight the essential role of lamins in NR formation by demonstrating that (over)expression of lamins can induce aberrant NR structures.
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Affiliation(s)
- Merel Stiekema
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, Maastricht, Netherlands
- GROW-School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, Netherlands
| | - Frederik Houben
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, Maastricht, Netherlands
- Department of Healthcare, PXL University College, Hasselt, Belgium
| | - Fons Verheyen
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, Maastricht, Netherlands
| | - Marcel Borgers
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, Maastricht, Netherlands
| | | | | | - Marc A. M. J. van Zandvoort
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, Maastricht, Netherlands
- GROW-School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, Netherlands
- CARIM-School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, Netherlands
- Institute for Molecular Cardiovascular Research IMCAR, RWTH Aachen University, Aachen, Germany
| | - Frans C. S. Ramaekers
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, Maastricht, Netherlands
- GROW-School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, Netherlands
| | - Jos L. V. Broers
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, Maastricht, Netherlands
- GROW-School for Oncology and Reproduction, Maastricht University Medical Centre, Maastricht, Netherlands
- CARIM-School for Cardiovascular Diseases, Maastricht University Medical Centre, Maastricht, Netherlands
- *Correspondence: Jos L. V. Broers,
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Lin WQ, Ngian ZK, Koh TW, Ong CT. Altered stability of nuclear lamin-B marks the onset of aging in male Drosophila. PLoS One 2022; 17:e0265223. [PMID: 35324942 PMCID: PMC8947137 DOI: 10.1371/journal.pone.0265223] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Accepted: 02/25/2022] [Indexed: 11/25/2022] Open
Abstract
Epigenetic alterations occur during aging, but it remains unclear what epigenetic features are associated with the onset of physiological decline in animals. Nuclear lamin-B forms the filamentous meshwork underneath the nuclear envelope, providing the structural scaffold necessary for genome organization and gene regulation. We found that reduced level of nuclear lamin-B protein coincides with the decline in locomotor activity and stress resistance in young adult male Drosophila. Ubiquitous lamin-B expression improves locomotor activity of the male flies at the expense of lower stress resistance and shorten lifespan. This observation suggests that tissue-specific expression of lamin-B may regulate different aspects of animal physiology during aging. To test this hypothesis, specific GAL-4 lines were used to drive the expression of lamin-B in specific neuronal populations and muscle tissues in male flies. Ectopic expression of lamin-B in the dopaminergic neurons within the protocerebral anterior medial region of the brain improves the locomotor activity of the male flies with little impact on their stress responses and lifespan. Interestingly, age-dependent decrease in the level of lamin-B protein is independent of its mRNA expression. Instead, cellular thermal shift assay showed that lamin-B and CP190 insulator protein undergo significant change in their solubility during aging. This suggests that the increased solubility of lamin-B protein may contribute to its reduced stability and degradation during aging.
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Affiliation(s)
- Wei-Qi Lin
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Zhen-Kai Ngian
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Tong-Wey Koh
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
| | - Chin-Tong Ong
- Temasek Life Sciences Laboratory, National University of Singapore, Singapore, Singapore
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
- * E-mail:
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Mechanisms of A-Type Lamin Targeting to Nuclear Ruptures Are Disrupted in LMNA- and BANF1-Associated Progerias. Cells 2022; 11:cells11050865. [PMID: 35269487 PMCID: PMC8909658 DOI: 10.3390/cells11050865] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2022] [Revised: 02/23/2022] [Accepted: 02/28/2022] [Indexed: 02/04/2023] Open
Abstract
Mutations in the genes LMNA and BANF1 can lead to accelerated aging syndromes called progeria. The protein products of these genes, A-type lamins and BAF, respectively, are nuclear envelope (NE) proteins that interact and participate in various cellular processes, including nuclear envelope rupture and repair. BAF localizes to sites of nuclear rupture and recruits NE-repair machinery, including the LEM-domain proteins, ESCRT-III complex, A-type lamins, and membranes. Here, we show that it is a mobile, nucleoplasmic population of A-type lamins that is rapidly recruited to ruptures in a BAF-dependent manner via BAF’s association with the Ig-like β fold domain of A-type lamins. These initially mobile lamins become progressively stabilized at the site of rupture. Farnesylated prelamin A and lamin B1 fail to localize to nuclear ruptures, unless that farnesylation is inhibited. Progeria-associated LMNA mutations inhibit the recruitment affected A-type lamin to nuclear ruptures, due to either permanent farnesylation or inhibition of BAF binding. A progeria-associated BAF mutant targets to nuclear ruptures but is unable to recruit A-type lamins. Together, these data reveal the mechanisms that determine how lamins respond to nuclear ruptures and how progeric mutations of LMNA and BANF1 impair recruitment of A-type lamins to nuclear ruptures.
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12
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Vahabikashi A, Adam SA, Medalia O, Goldman RD. Nuclear lamins: Structure and function in mechanobiology. APL Bioeng 2022; 6:011503. [PMID: 35146235 PMCID: PMC8810204 DOI: 10.1063/5.0082656] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 01/11/2022] [Indexed: 12/11/2022] Open
Abstract
Nuclear lamins are type V intermediate filament proteins that polymerize into complex filamentous meshworks at the nuclear periphery and in less structured forms throughout the nucleoplasm. Lamins interact with a wide range of nuclear proteins and are involved in numerous nuclear and cellular functions. Within the nucleus, they play roles in chromatin organization and gene regulation, nuclear shape, size, and mechanics, and the organization and anchorage of nuclear pore complexes. At the whole cell level, they are involved in the organization of the cytoskeleton, cell motility, and mechanotransduction. The expression of different lamin isoforms has been associated with developmental progression, differentiation, and tissue-specific functions. Mutations in lamins and their binding proteins result in over 15 distinct human diseases, referred to as laminopathies. The laminopathies include muscular (e.g., Emery-Dreifuss muscular dystrophy and dilated cardiomyopathy), neurological (e.g., microcephaly), and metabolic (e.g., familial partial lipodystrophy) disorders as well as premature aging diseases (e.g., Hutchinson-Gilford Progeria and Werner syndromes). How lamins contribute to the etiology of laminopathies is still unknown. In this review article, we summarize major recent findings on the structure, organization, and multiple functions of lamins in nuclear and more global cellular processes.
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Affiliation(s)
- Amir Vahabikashi
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Stephen A. Adam
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
| | - Ohad Medalia
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Robert D. Goldman
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois 60611, USA
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13
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de Leeuw R, Kronenberg-Tenga R, Eibauer M, Medalia O. Filament assembly of the C. elegans lamin in the absence of helix 1A. Nucleus 2022; 13:49-57. [PMID: 35130129 PMCID: PMC8824219 DOI: 10.1080/19491034.2022.2032917] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Lamins are the major constituent of the nuclear lamina, a protein meshwork underlying the inner nuclear membrane. Nuclear lamins are type V intermediate filaments that assemble into ~3.5 nm thick filaments. To date, only the conditions for the in vitro assembly of Caenorhabditis elegans lamin (Ce-lamin) are known. Here, we investigated the assembly of Ce-lamin filaments by cryo-electron microscopy and tomography. We show that Ce-lamin is composed of ~3.5 nm protofilaments that further interact in vitro and are often seen as 6–8 nm thick filaments. We show that the assembly of lamin filaments is undisturbed by the removal of flexible domains, that is, the intrinsically unstructured head and tail domains. In contrast, much of the coiled-coil domains are scaffold elements that are essential for filament assembly. Moreover, our results suggest that Ce-lamin helix 1A has a minor scaffolding role but is important to the lateral assembly regulation of lamin protofilaments.
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Affiliation(s)
- Rebecca de Leeuw
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | | | - Matthias Eibauer
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Ohad Medalia
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
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14
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Nuclear Dynamics and Chromatin Structure: Implications for Pancreatic Cancer. Cells 2021; 10:cells10102624. [PMID: 34685604 PMCID: PMC8534098 DOI: 10.3390/cells10102624] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2021] [Revised: 09/20/2021] [Accepted: 09/27/2021] [Indexed: 12/14/2022] Open
Abstract
Changes in nuclear shape have been extensively associated with the dynamics and functionality of cancer cells. In most normal cells, nuclei have a regular ellipsoid shape and minimal variation in nuclear size; however, an irregular nuclear contour and abnormal nuclear size is often observed in cancer, including pancreatic cancer. Furthermore, alterations in nuclear morphology have become the 'gold standard' for tumor staging and grading. Beyond the utility of altered nuclear morphology as a diagnostic tool in cancer, the implications of altered nuclear structure for the biology and behavior of cancer cells are profound as changes in nuclear morphology could impact cellular responses to physical strain, adaptation during migration, chromatin organization, and gene expression. Here, we aim to highlight and discuss the factors that regulate nuclear dynamics and their implications for pancreatic cancer biology.
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15
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Stiekema M, Ramaekers FCS, Kapsokalyvas D, van Zandvoort MAMJ, Veltrop RJA, Broers JLV. Super-Resolution Imaging of the A- and B-Type Lamin Networks: A Comparative Study of Different Fluorescence Labeling Procedures. Int J Mol Sci 2021; 22:ijms221910194. [PMID: 34638534 PMCID: PMC8508656 DOI: 10.3390/ijms221910194] [Citation(s) in RCA: 3] [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: 06/22/2021] [Revised: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 12/31/2022] Open
Abstract
A- and B-type lamins are type V intermediate filament proteins. Mutations in the genes encoding these lamins cause rare diseases, collectively called laminopathies. A fraction of the cells obtained from laminopathy patients show aberrations in the localization of each lamin subtype, which may represent only the minority of the lamina disorganization. To get a better insight into more delicate and more abundant lamina abnormalities, the lamin network can be studied using super-resolution microscopy. We compared confocal scanning laser microscopy and stimulated emission depletion (STED) microscopy in combination with different fluorescence labeling approaches for the study of the lamin network. We demonstrate the suitability of an immunofluorescence staining approach when using STED microscopy, by determining the lamin layer thickness and the degree of lamin A and B1 colocalization as detected in fixed fibroblasts (co-)stained with lamin antibodies or (co-)transfected with EGFP/YFP lamin constructs. This revealed that immunofluorescence staining of cells does not lead to consequent changes in the detected lamin layer thickness, nor does it influence the degree of colocalization of lamin A and B1, when compared to the transfection approach. Studying laminopathy patient dermal fibroblasts (LMNA c.1130G>T (p.(Arg377Leu)) variant) confirmed the suitability of immunofluorescence protocols in STED microscopy, which circumvents the need for less convenient transfection steps. Furthermore, we found a significant decrease in lamin A/C and B1 colocalization in these patient fibroblasts, compared to normal human dermal fibroblasts. We conclude that super-resolution light microscopy combined with immunofluorescence protocols provides a potential tool to detect structural lamina differences between normal and laminopathy patient fibroblasts.
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Affiliation(s)
- Merel Stiekema
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands; (M.S.); (F.C.S.R.); (D.K.); (M.A.M.J.v.Z.)
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
| | - Frans C. S. Ramaekers
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands; (M.S.); (F.C.S.R.); (D.K.); (M.A.M.J.v.Z.)
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
| | - Dimitrios Kapsokalyvas
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands; (M.S.); (F.C.S.R.); (D.K.); (M.A.M.J.v.Z.)
- Interdisciplinary Center for Clinical Research, IZKF, RWTH Aachen University, 52074 Aachen, Germany
| | - Marc A. M. J. van Zandvoort
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands; (M.S.); (F.C.S.R.); (D.K.); (M.A.M.J.v.Z.)
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
- CARIM-School for Cardiovascular Diseases, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
- Institute for Molecular Cardiovascular Research IMCAR, RWTH Aachen University, 52074 Aachen, Germany
| | - Rogier J. A. Veltrop
- Institute for Molecular Cardiovascular Research IMCAR, RWTH Aachen University, 52074 Aachen, Germany
- Department of Biochemistry, Cardiovascular Research Institute Maastricht, Maastricht University, 6200 MD Maastricht, The Netherlands;
| | - Jos L. V. Broers
- Department of Genetics and Cell Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands; (M.S.); (F.C.S.R.); (D.K.); (M.A.M.J.v.Z.)
- GROW-School for Oncology and Developmental Biology, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
- CARIM-School for Cardiovascular Diseases, Maastricht University Medical Centre, 6200 MD Maastricht, The Netherlands
- Correspondence: ; Tel.: +31-433881366
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16
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Bend, Push, Stretch: Remarkable Structure and Mechanics of Single Intermediate Filaments and Meshworks. Cells 2021; 10:cells10081960. [PMID: 34440729 PMCID: PMC8394331 DOI: 10.3390/cells10081960] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 07/22/2021] [Accepted: 07/28/2021] [Indexed: 12/11/2022] Open
Abstract
The cytoskeleton of the eukaryotic cell provides a structural and functional scaffold enabling biochemical and cellular functions. While actin and microtubules form the main framework of the cell, intermediate filament networks provide unique mechanical properties that increase the resilience of both the cytoplasm and the nucleus, thereby maintaining cellular function while under mechanical pressure. Intermediate filaments (IFs) are imperative to a plethora of regulatory and signaling functions in mechanotransduction. Mutations in all types of IF proteins are known to affect the architectural integrity and function of cellular processes, leading to debilitating diseases. The basic building block of all IFs are elongated α-helical coiled-coils that assemble hierarchically into complex meshworks. A remarkable mechanical feature of IFs is the capability of coiled-coils to metamorphize into β-sheets under stress, making them one of the strongest and most resilient mechanical entities in nature. Here, we discuss structural and mechanical aspects of IFs with a focus on nuclear lamins and vimentin.
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17
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Jia Z, Zhang Y, Deng J, Guo Y, Du Y, Wang G, Xu J, Li X. A novel LMNA indel mutation identified in a family with atrioventricular block and atrial fibrillation. Medicine (Baltimore) 2021; 100:e25910. [PMID: 34106654 PMCID: PMC8133043 DOI: 10.1097/md.0000000000025910] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2020] [Accepted: 04/22/2021] [Indexed: 12/04/2022] Open
Abstract
It is well known that many genetic factors are involved in the occurrence and progression of atrioventricular block (AV block) and atrial fibrillation (AF). However, the genetic variants discovered so far have only explained parts of these processes. More genes and variants remain to be identified. In the present study, a three-generation family with an autosomal dominant form of AV block and AF was enrolled. Whole exome sequencing was conducted in three affected and one unaffected family member. A total of 64 nonsynonymous variants was shared by three affected individuals and not present in the unaffected individual. By selection of variants absent in the known databases and were predicted to be deleterious, 4 novel variants were identified. Only one novel frameshift insertion in the LMNA gene (c.825_826insCAGG) was identified in another affected family member and not detected in other non-affected family members and the 100 controls. Our finding expanded the spectrum of variants associated with AV block and AF, and was valuable in the genetic diagnosis of AV block and AF.
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Affiliation(s)
| | | | | | | | - Yimei Du
- Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Gang Wang
- Shanxi Cardiovascular Hospital, Taiyuan
| | - Jiyao Xu
- Shanxi Cardiovascular Hospital, Taiyuan
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18
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Kittisopikul M, Shimi T, Tatli M, Tran JR, Zheng Y, Medalia O, Jaqaman K, Adam SA, Goldman RD. Computational analyses reveal spatial relationships between nuclear pore complexes and specific lamins. J Cell Biol 2021; 220:e202007082. [PMID: 33570570 PMCID: PMC7883741 DOI: 10.1083/jcb.202007082] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 10/15/2020] [Accepted: 01/05/2021] [Indexed: 12/29/2022] Open
Abstract
Nuclear lamin isoforms form fibrous meshworks associated with nuclear pore complexes (NPCs). Using datasets prepared from subpixel and segmentation analyses of 3D-structured illumination microscopy images of WT and lamin isoform knockout mouse embryo fibroblasts, we determined with high precision the spatial association of NPCs with specific lamin isoform fibers. These relationships are retained in the enlarged lamin meshworks of Lmna-/- and Lmnb1-/- fibroblast nuclei. Cryo-ET observations reveal that the lamin filaments composing the fibers contact the nucleoplasmic ring of NPCs. Knockdown of the ring-associated nucleoporin ELYS induces NPC clusters that exclude lamin A/C fibers but include LB1 and LB2 fibers. Knockdown of the nucleoporin TPR or NUP153 alters the arrangement of lamin fibers and NPCs. Evidence that the number of NPCs is regulated by specific lamin isoforms is presented. Overall the results demonstrate that lamin isoforms and nucleoporins act together to maintain the normal organization of lamin meshworks and NPCs within the nuclear envelope.
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Affiliation(s)
- Mark Kittisopikul
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Takeshi Shimi
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
- Cell Biology Center and World Research Hub Initiative, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Meltem Tatli
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Joseph Riley Tran
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD
| | - Ohad Medalia
- Department of Biochemistry, University of Zurich, Zurich, Switzerland
| | - Khuloud Jaqaman
- Department of Biophysics, University of Texas Southwestern Medical Center, Dallas, TX
- Lyda Hill Department of Bioinformatics, University of Texas Southwestern Medical Center, Dallas, TX
| | - Stephen A. Adam
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
| | - Robert D. Goldman
- Department of Cell and Developmental Biology, Feinberg School of Medicine, Northwestern University, Chicago, IL
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19
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Kronenberg-Tenga R, Tatli M, Eibauer M, Wu W, Shin JY, Bonne G, Worman HJ, Medalia O. A lamin A/C variant causing striated muscle disease provides insights into filament organization. J Cell Sci 2021; 134:jcs.256156. [PMID: 33536248 DOI: 10.1242/jcs.256156] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 01/26/2021] [Indexed: 12/31/2022] Open
Abstract
The LMNA gene encodes the A-type lamins, which polymerize into ∼3.5-nm-thick filaments and, together with B-type lamins and associated proteins, form the nuclear lamina. Mutations in LMNA cause a wide variety of pathologies. In this study, we analyzed the nuclear lamina of embryonic fibroblasts from Lmna H222P/H222P mice, which develop cardiomyopathy and muscular dystrophy. Although the organization of the lamina appeared unaltered, there were changes in chromatin and B-type lamin expression. An increase in nuclear size and consequently a relative reduction in heterochromatin near the lamina allowed for a higher resolution structural analysis of lamin filaments using cryo-electron tomography. This was most apparent when visualizing lamin filaments in situ and using a nuclear extraction protocol. Averaging of individual segments of filaments in Lmna H222P/H222P mouse fibroblasts resolved two polymers that constitute the mature filaments. Our findings provide better views of the organization of lamin filaments and the effect of a striated muscle disease-causing mutation on nuclear structure.
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Affiliation(s)
- Rafael Kronenberg-Tenga
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Meltem Tatli
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Matthias Eibauer
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Wei Wu
- Department of Medicine and Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Ji-Yeon Shin
- Department of Medicine and Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Gisèle Bonne
- Sorbonne Université, INSERM, Centre de Recherche en Myologie, Institut de Myologie, F-75651 Paris CEDEX 13, France
| | - Howard J Worman
- Department of Medicine and Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Ohad Medalia
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
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20
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Ding B, Tang Y, Ma S, Akter M, Liu ML, Zang T, Zhang CL. Disease Modeling with Human Neurons Reveals LMNB1 Dysregulation Underlying DYT1 Dystonia. J Neurosci 2021; 41:2024-2038. [PMID: 33468570 PMCID: PMC7939088 DOI: 10.1523/jneurosci.2507-20.2020] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 12/23/2020] [Accepted: 12/30/2020] [Indexed: 02/08/2023] Open
Abstract
DYT1 dystonia is a hereditary neurologic movement disorder characterized by uncontrollable muscle contractions. It is caused by a heterozygous mutation in Torsin A (TOR1A), a gene encoding a membrane-embedded ATPase. While animal models provide insights into disease mechanisms, significant species-dependent differences exist since animals with the identical heterozygous mutation fail to show pathology. Here, we model DYT1 by using human patient-specific cholinergic motor neurons (MNs) that are generated through either direct conversion of patients' skin fibroblasts or differentiation of induced pluripotent stem cells (iPSCs). These human MNs with the heterozygous TOR1A mutation show reduced neurite length and branches, markedly thickened nuclear lamina, disrupted nuclear morphology, and impaired nucleocytoplasmic transport (NCT) of mRNAs and proteins, whereas they lack the perinuclear "blebs" that are often observed in animal models. Furthermore, we uncover that the nuclear lamina protein LMNB1 is upregulated in DYT1 cells and exhibits abnormal subcellular distribution in a cholinergic MNs-specific manner. Such dysregulation of LMNB1 can be recapitulated by either ectopic expression of the mutant TOR1A gene or shRNA-mediated downregulation of endogenous TOR1A in healthy control MNs. Interestingly, downregulation of LMNB1 can largely ameliorate all the cellular defects in DYT1 MNs. These results reveal the value of disease modeling with human patient-specific neurons and indicate that dysregulation of LMNB1, a crucial component of the nuclear lamina, may constitute a major molecular mechanism underlying DYT1 pathology.SIGNIFICANCE STATEMENT Inaccessibility to patient neurons greatly impedes our understanding of the pathologic mechanisms for dystonia. In this study, we employ reprogrammed human patient-specific motor neurons (MNs) to model DYT1, the most severe hereditary form of dystonia. Our results reveal disease-dependent deficits in nuclear morphology and nucleocytoplasmic transport (NCT). Most importantly, we further identify LMNB1 dysregulation as a major contributor to these deficits, uncovering a new pathologic mechanism for DYT1 dystonia.
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Affiliation(s)
- Baojin Ding
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- Department of Biology, University of Louisiana at Lafayette, Lafayette, Louisiana 70503
| | - Yu Tang
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
- National Clinical Research Center for Geriatric Disorders, Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, Hunan Province 410008, China
| | - Shuaipeng Ma
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Masuma Akter
- Department of Biology, University of Louisiana at Lafayette, Lafayette, Louisiana 70503
| | - Meng-Lu Liu
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Tong Zang
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
| | - Chun-Li Zhang
- Department of Molecular Biology, Hamon Center for Regenerative Science and Medicine, University of Texas Southwestern Medical Center, Dallas, Texas 75390
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21
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Sapra KT, Qin Z, Dubrovsky-Gaupp A, Aebi U, Müller DJ, Buehler MJ, Medalia O. Nonlinear mechanics of lamin filaments and the meshwork topology build an emergent nuclear lamina. Nat Commun 2020; 11:6205. [PMID: 33277502 PMCID: PMC7718915 DOI: 10.1038/s41467-020-20049-8] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Accepted: 11/11/2020] [Indexed: 01/16/2023] Open
Abstract
The nuclear lamina—a meshwork of intermediate filaments termed lamins—is primarily responsible for the mechanical stability of the nucleus in multicellular organisms. However, structural-mechanical characterization of lamin filaments assembled in situ remains elusive. Here, we apply an integrative approach combining atomic force microscopy, cryo-electron tomography, network analysis, and molecular dynamics simulations to directly measure the mechanical response of single lamin filaments in three-dimensional meshwork. Endogenous lamin filaments portray non-Hookean behavior – they deform reversibly at a few hundred picoNewtons and stiffen at nanoNewton forces. The filaments are extensible, strong and tough similar to natural silk and superior to the synthetic polymer Kevlar®. Graph theory analysis shows that the lamin meshwork is not a random arrangement of filaments but exhibits small-world properties. Our results suggest that lamin filaments arrange to form an emergent meshwork whose topology dictates the mechanical properties of individual filaments. The quantitative insights imply a role of meshwork topology in laminopathies. Mechanical strength of in situ assembled nuclear lamin filaments arranged in a 3D meshwork is unclear. Here, using mechanical, structural and simulation tools, the authors report the hierarchical organization of the lamin meshwork that imparts strength and toughness to lamin filaments at par with silk and Kevlar®
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Affiliation(s)
- K Tanuj Sapra
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland. .,Department of Biosystems Science and Bioengineering, ETH Zurich, Mattenstrasse 26, 4058, Basel, Switzerland.
| | - Zhao Qin
- Laboratory for Atomistic and Molecular Mechanics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.,Department of Civil and Environmental Engineering, Syracuse University, Syracuse, NY, 13244, USA
| | - Anna Dubrovsky-Gaupp
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - Ueli Aebi
- Biozentrum, University of Basel, CH-4056, Basel, Switzerland
| | - Daniel J Müller
- Department of Biosystems Science and Bioengineering, ETH Zurich, Mattenstrasse 26, 4058, Basel, Switzerland
| | - Markus J Buehler
- Laboratory for Atomistic and Molecular Mechanics, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA
| | - Ohad Medalia
- Department of Biochemistry, University of Zurich, Winterthurerstrasse 190, 8057, Zurich, Switzerland.
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22
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Tenga R, Medalia O. Structure and unique mechanical aspects of nuclear lamin filaments. Curr Opin Struct Biol 2020; 64:152-159. [DOI: 10.1016/j.sbi.2020.06.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Revised: 06/15/2020] [Accepted: 06/21/2020] [Indexed: 11/15/2022]
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23
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The Molecular Basis and Biologic Significance of the β-Dystroglycan-Emerin Interaction. Int J Mol Sci 2020; 21:ijms21175944. [PMID: 32824881 PMCID: PMC7504044 DOI: 10.3390/ijms21175944] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 07/29/2020] [Accepted: 08/04/2020] [Indexed: 01/04/2023] Open
Abstract
β-dystroglycan (β-DG) assembles with lamins A/C and B1 and emerin at the nuclear envelope (NE) to maintain proper nuclear architecture and function. To provide insight into the nuclear function of β-DG, we characterized the interaction between β-DG and emerin at the molecular level. Emerin is a major NE protein that regulates multiple nuclear processes and whose deficiency results in Emery–Dreifuss muscular dystrophy (EDMD). Using truncated variants of β-DG and emerin, via a series of in vitro and in vivo binding experiments and a tailored computational analysis, we determined that the β-DG–emerin interaction is mediated at least in part by their respective transmembrane domains (TM). Using surface plasmon resonance assays we showed that emerin binds to β-DG with high affinity (KD in the nanomolar range). Remarkably, the analysis of cells in which DG was knocked out demonstrated that loss of β-DG resulted in a decreased emerin stability and impairment of emerin-mediated processes. β-DG and emerin are reciprocally required for their optimal targeting within the NE, as shown by immunofluorescence, western blotting and immunoprecipitation assays using emerin variants with mutations in the TM domain and B-lymphocytes of a patient with EDMD. In summary, we demonstrated that β-DG plays a role as an emerin interacting partner modulating its stability and function.
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24
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Structural and Mechanical Aberrations of the Nuclear Lamina in Disease. Cells 2020; 9:cells9081884. [PMID: 32796718 PMCID: PMC7464082 DOI: 10.3390/cells9081884] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 08/02/2020] [Accepted: 08/10/2020] [Indexed: 12/13/2022] Open
Abstract
The nuclear lamins are the major components of the nuclear lamina in the nuclear envelope. Lamins are involved in numerous functions, including a role in providing structural support to the cell and the mechanosensing of the cell. Mutations in the genes encoding for lamins lead to the rare diseases termed laminopathies. However, not only laminopathies show alterations in the nuclear lamina. Deregulation of lamin expression is reported in multiple cancers and several viral infections lead to a disrupted nuclear lamina. The structural and mechanical effects of alterations in the nuclear lamina can partly explain the phenotypes seen in disease, such as muscular weakness in certain laminopathies and transmigration of cancer cells. However, a lot of answers to questions about the relation between changes in the nuclear lamina and disease development remain elusive. Here, we review the current understandings of the contribution of the nuclear lamina in the structural support and mechanosensing of healthy and diseased cells.
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25
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Bossone KA, Ellis JA, Holaska JM. Histone acetyltransferase inhibition rescues differentiation of emerin-deficient myogenic progenitors. Muscle Nerve 2020; 62:128-136. [PMID: 32304242 DOI: 10.1002/mus.26892] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 03/05/2020] [Accepted: 04/07/2020] [Indexed: 12/20/2022]
Abstract
INTRODUCTION Emery-Dreifuss muscular dystrophy (EDMD) is a disease characterized by skeletal muscle wasting, major tendon contractures, and cardiac conduction defects. Mutations in the gene encoding emerin cause EDMD1. Our previous studies suggested that emerin activation of histone deacetylase 3 (HDAC3) to reduce histone 4-lysine 5 (H4K5) acetylation (ac) is important for myogenic differentiation. METHODS Pharmacological inhibitors (Nu9056, L002) of histone acetyltransferases targeting acetylated H4K5 were used to test whether increased acetylated H4K5 was responsible for the impaired differentiation seen in emerin-deficient myogenic progenitors. RESULTS Nu9056 and L002 rescued impaired differentiation in emerin deficiency. SRT1720, which inhibits the nicotinamide adenine dinucleotide (NAD)+ -dependent deacetylase sirtuin 1 (SIRT1), failed to rescue myotube formation. DISCUSSION We conclude that emerin regulation of HDAC3 activity to affect H4K5 acetylation dynamics is important for myogenic differentiation. Targeting H4K5ac dynamics represents a potential new strategy for ameliorating the skeletal muscle wasting seen in EDMD1.
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Affiliation(s)
- Katherine A Bossone
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, New Jersey, United States.,Department of Pharmaceutical Sciences, University of the Sciences, Philadelphia, Pennsylvania, United States
| | - Joseph A Ellis
- Department of Pharmaceutical Sciences, University of the Sciences, Philadelphia, Pennsylvania, United States
| | - James M Holaska
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, New Jersey, United States.,Department of Pharmaceutical Sciences, University of the Sciences, Philadelphia, Pennsylvania, United States
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Kirby TJ. Mechanosensitive pathways controlling translation regulatory processes in skeletal muscle and implications for adaptation. J Appl Physiol (1985) 2019; 127:608-618. [PMID: 31295035 DOI: 10.1152/japplphysiol.01031.2018] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The ability of myofibers to sense and respond appropriately to mechanical signals is one of the primary determinants of the skeletal muscle phenotype. In response to a change in mechanical load, muscle cells alter their protein metabolism, primarily through the regulation of protein synthesis rate. Protein synthesis rates are determined by both translation efficiency and translational capacity within the muscle. Translational capacity is strongly determined by the ribosome content of the muscle; thus the regulation of ribosomal biogenesis by mechanical inputs has been an area of recent interest. Despite the clear association between mechanical signals and changes in protein metabolism, the molecular pathways that link these events are still not fully elucidated. This review focuses on recent studies looking at how mechanosignaling impacts translational events. The role of impaired mechanotransduction in aging is discussed, as is the connection between age-dependent signaling defects and compromised ribosomal biogenesis during mechanical overload. Finally, emerging evidence suggests that the nucleus can act as a mechanosensitive element and that this mode of mechanotransduction may have an important role in skeletal muscle physiology and adaptation.
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Affiliation(s)
- Tyler J Kirby
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, New York.,Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York
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27
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Brookes E, Riccio A. Location, location, location: nuclear structure regulates gene expression in neurons. Curr Opin Neurobiol 2019; 59:16-25. [PMID: 31005709 DOI: 10.1016/j.conb.2019.03.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2018] [Revised: 02/27/2019] [Accepted: 03/18/2019] [Indexed: 12/27/2022]
Abstract
Genome architecture plays a critical role in regulating the expression of genes that are essential for nervous system development. During neuronal differentiation, spatially and temporally regulated transcription allows neuronal migration, the growth of dendrites and axons, and at later stages, synaptic formation and the establishment of neuronal circuitry. Genome topology and relocation of gene loci within the nucleus are now regarded as key factors that contribute to transcriptional regulation. Here, we review recent work supporting the hypothesis that the dynamic organization of chromatin within the nucleus impacts gene activation in response to extrinsic signalling and during neuronal differentiation. The consequences of disruption of the genome architecture on neuronal health will be also discussed.
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Affiliation(s)
- Emily Brookes
- MRC Laboratory of Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK
| | - Antonella Riccio
- MRC Laboratory of Molecular Cell Biology, University College London, Gower Street, London WC1E 6BT, UK.
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28
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Padiath QS. Autosomal Dominant Leukodystrophy: A Disease of the Nuclear Lamina. Front Cell Dev Biol 2019; 7:41. [PMID: 30949481 PMCID: PMC6435485 DOI: 10.3389/fcell.2019.00041] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Accepted: 03/05/2019] [Indexed: 01/23/2023] Open
Abstract
The nuclear lamina is a fibrous meshwork of proteins found adjacent to the inner nuclear membrane that plays a critical role in the maintenance of nuclear architecture. Made up of A and B type lamins, the nuclear lamina has recently been shown to contribute to numerous cellular functions such as chromatin organization, DNA replication, cellular proliferation, senescence, and aging. While at least a dozen disorders are associated with LMNA, the focus of this review is Autosomal Dominant Leukodystrophy (ADLD), the only disease associated with the lamin B1 gene (LMNB1). ADLD is a fatal, adult onset CNS demyelinating disorder that is caused by either genomic duplications involving LMNB1 or deletions upstream of the gene. Both mutation types result in increased LMNB1 gene expression. How the increased levels of this widely expressed nuclear structural component results a phenotype as specific as demyelination is a great mystery. This review summarizes what is currently known about the disease and describes recent work using animal and cell culture models that have provided critical insights into ADLD pathological mechanisms. The delineation of these pathways provides a fascinating glimpse into entirely novel roles for the nuclear lamina and will be critical for the identification of therapies for this fatal disease.
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Affiliation(s)
- Quasar S Padiath
- Department of Human Genetics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA, United States
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29
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Grafe M, Batsios P, Meyer I, Lisin D, Baumann O, Goldberg MW, Gräf R. Supramolecular Structures of the Dictyostelium Lamin NE81. Cells 2019; 8:cells8020162. [PMID: 30781468 PMCID: PMC6406624 DOI: 10.3390/cells8020162] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/12/2019] [Accepted: 02/15/2019] [Indexed: 12/27/2022] Open
Abstract
Nuclear lamins are nucleus-specific intermediate filaments (IF) found at the inner nuclear membrane (INM) of the nuclear envelope (NE). Together with nuclear envelope transmembrane proteins, they form the nuclear lamina and are crucial for gene regulation and mechanical robustness of the nucleus and the whole cell. Recently, we characterized Dictyostelium NE81 as an evolutionarily conserved lamin-like protein, both on the sequence and functional level. Here, we show on the structural level that the Dictyostelium NE81 is also capable of assembling into filaments, just as metazoan lamin filament assemblies. Using field-emission scanning electron microscopy, we show that NE81 expressed in Xenopous oocytes forms filamentous structures with an overall appearance highly reminiscent of Xenopus lamin B2. The in vitro assembly properties of recombinant His-tagged NE81 purified from Dictyostelium extracts are very similar to those of metazoan lamins. Super-resolution stimulated emission depletion (STED) and expansion microscopy (ExM), as well as transmission electron microscopy of negatively stained purified NE81, demonstrated its capability of forming filamentous structures under low-ionic-strength conditions. These results recommend Dictyostelium as a non-mammalian model organism with a well-characterized nuclear envelope involving all relevant protein components known in animal cells.
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Affiliation(s)
- Marianne Grafe
- Department of Cell Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany.
| | - Petros Batsios
- Department of Cell Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany.
| | - Irene Meyer
- Department of Cell Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany.
| | - Daria Lisin
- Department of Cell Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany.
| | - Otto Baumann
- Department of Animal Physiology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany.
| | - Martin W Goldberg
- Department of Biosciences, Durham University, Science Laboratories, South Road, Durham DH1 3LE, UK.
| | - Ralph Gräf
- Department of Cell Biology, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476 Potsdam-Golm, Germany.
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30
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Shevelyov YY, Ulianov SV. The Nuclear Lamina as an Organizer of Chromosome Architecture. Cells 2019; 8:E136. [PMID: 30744037 PMCID: PMC6406483 DOI: 10.3390/cells8020136] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 02/04/2019] [Accepted: 02/06/2019] [Indexed: 01/20/2023] Open
Abstract
The nuclear lamina (NL) is a meshwork of lamins and lamin-associated proteins adjoining the inner side of the nuclear envelope. In early embryonic cells, the NL mainly suppresses background transcription, whereas, in differentiated cell types, its disruption affects gene expression more severely. Normally, the NL serves as a backbone for multiple chromatin anchoring sites, thus shaping the spatial organization of chromosomes in the interphase nucleus. However, upon cell senescence, aging, or in some types of terminally differentiated cells and lamin-associated diseases, the loss of NL-chromatin tethering causes drastic alterations in chromosome architecture. Here, we provide an overview of the recent advances in the field of NL-chromatin interactions, focusing on their impact on chromatin positioning, compaction, repression, and spatial organization.
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Affiliation(s)
- Yuri Y. Shevelyov
- Department of Molecular Genetics of Cell, Institute of Molecular Genetics, Russian Academy of Sciences, Moscow 123182, Russia;
| | - Sergey V. Ulianov
- Division of the Regulation of Transcription and Chromatin Dynamics, Institute of Gene Biology, Russian Academy of Sciences, Moscow 119334, Russia;
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31
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Deal SL, Yamamoto S. Unweaving the role of nuclear Lamins in neural circuit integrity. Cell Stress 2018; 2:219-224. [PMID: 31223139 PMCID: PMC6558928 DOI: 10.15698/cst2018.09.151] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 09/05/2018] [Accepted: 09/05/2018] [Indexed: 02/02/2023] Open
Abstract
Lamins are type-V intermediate filament proteins that comprise the nuclear lamina. Although once considered static structural components that provide physical support to the inner nuclear envelope, recent studies are revealing additional functional and regulatory roles for Lamins in chromatin organization, gene regulation, DNA repair, cell division and signal transduction. In this issue of Cell Stress, Oyston et al. (2018) reports the function of Lamin in the maintenance of nervous system integrity and neural circuit function using Drosophila. A number of laminopathies in humans exhibit age-dependent neurological phenotypes, but understanding how defects in specific neural cell types or circuitries contribute to patient phenotypes is very challenging. Drosophila provides a simple yet sophisticated system to begin untangling the vulnerability of diverse neuronal cell types and circuits against cellular stressors induced by defects in nuclear lamina organization.
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Affiliation(s)
- Samantha L. Deal
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX 77030
| | - Shinya Yamamoto
- Program in Developmental Biology, Baylor College of Medicine (BCM), Houston, TX 77030
- Department of Molecular and Human Genetics, BCM, Houston, TX 77030
- Department of Neuroscience, BCM, Houston, TX 77030
- Jan and Dan Duncan Neurological Research Institute, Texas Children’s Hospital, Houston, TX
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