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Lisowska M, Rowińska M, Suszyńska A, Bearzi C, Łaczmańska I, Hanusek J, Kunik A, Dzianisava V, Rzepecki R, Machowska M, Piekarowicz K. Human iPSC-Derived Muscle Cells as a New Model for Investigation of EDMD1 Pathogenesis. Int J Mol Sci 2025; 26:1539. [PMID: 40004006 PMCID: PMC11855679 DOI: 10.3390/ijms26041539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2024] [Revised: 01/31/2025] [Accepted: 02/05/2025] [Indexed: 02/27/2025] Open
Abstract
Emery-Dreifuss muscular dystrophy type 1 (EDMD1) is a rare genetic disease caused by mutations in the EMD gene, which encodes the nuclear envelope protein emerin. Despite understanding the genetic basis of the disease, the molecular mechanism underlying muscle and cardiac pathogenesis remains elusive. Progress is restricted by the limited availability of patient-derived samples; therefore, there is an urgent need for human-specific cellular models. In this study, we present the generation and characterization of induced pluripotent stem cell (iPSC) lines derived from EDMD1 patients carrying EMD mutations that lead to truncated or absent emerin, together with iPSCs from healthy donor. The patient-specific iPSCs exhibit stable karyotypes, maintain appropriate morphology, express pluripotency markers, and demonstrate the ability to differentiate into three germ layers. To model EDMD1, these iPSCs were differentiated into myogenic progenitors, myoblasts, and multinucleated myotubes, which represent all stages of myogenesis. Each developmental stage was validated by the presence of stage-specific markers, ensuring the accuracy of the model. We present the first iPSC-based in vitro platform that captures the complexity of EDMD1 pathogenesis during myogenesis. This model can significantly contribute to understanding disease mechanisms and develop the targeted therapeutic strategies for EDMD1.
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Affiliation(s)
- Marta Lisowska
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Marta Rowińska
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Aleksandra Suszyńska
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Claudia Bearzi
- Institute for Biomedical Technologies, National Research Council, 20054 Segrate, Milan, Italy
| | - Izabela Łaczmańska
- Department of Genetics, Wrocław Medical University, 50-368 Wrocław, Poland
| | - Julia Hanusek
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Amanda Kunik
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Volha Dzianisava
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Ryszard Rzepecki
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Magdalena Machowska
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
| | - Katarzyna Piekarowicz
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wrocław, 50-383 Wrocław, Poland
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Wada E, Matsumoto K, Susumu N, Kato M, Hayashi YK. Emerin deficiency does not exacerbate cardiomyopathy in a murine model of Emery-Dreifuss muscular dystrophy caused by an LMNA gene mutation. J Physiol Sci 2023; 73:27. [PMID: 37940872 PMCID: PMC10717240 DOI: 10.1186/s12576-023-00886-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Accepted: 10/20/2023] [Indexed: 11/10/2023]
Abstract
Emery-Dreifuss muscular dystrophy (EDMD), caused by mutations in genes encoding nuclear envelope proteins, is clinically characterized by muscular dystrophy, early joint contracture, and life-threatening cardiac abnormalities. To elucidate the pathophysiological mechanisms underlying striated muscle involvement in EDMD, we previously established a murine model with mutations in Emd and Lmna (Emd-/-/LmnaH222P/H222P; EH), and reported exacerbated skeletal muscle phenotypes and no notable cardiac phenotypes at 12 weeks of age. We predicted that lack of emerin in LmnaH222P/H222P mice causes an earlier onset and more pronounced cardiac dysfunction at later stages. In this study, cardiac abnormalities of EDMD mice were compared at 18 and 30 weeks of age. Contrary to our expectations, physiological and histological analyses indicated that emerin deficiency causes no prominent differences of cardiac involvement in LmnaH222P/H222P mice. These results suggest that emerin does not contribute to cardiomyopathy progression in LmnaH222P/H222P mice.
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Affiliation(s)
- Eiji Wada
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Kohei Matsumoto
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Nao Susumu
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Megumi Kato
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Yukiko K Hayashi
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan.
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Mackels L, Liu X, Bonne G, Servais L. TOR1AIP1-Associated Nuclear Envelopathies. Int J Mol Sci 2023; 24:ijms24086911. [PMID: 37108075 PMCID: PMC10138496 DOI: 10.3390/ijms24086911] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2023] [Revised: 03/23/2023] [Accepted: 03/23/2023] [Indexed: 04/29/2023] Open
Abstract
Human TOR1AIP1 encodes LAP1, a nuclear envelope protein expressed in most human tissues, which has been linked to various biological processes and human diseases. The clinical spectrum of diseases related to mutations in TOR1AIP1 is broad, including muscular dystrophy, congenital myasthenic syndrome, cardiomyopathy, and multisystemic disease with or without progeroid features. Although rare, these recessively inherited disorders often lead to early death or considerable functional impairment. Developing a better understanding of the roles of LAP1 and mutant TOR1AIP1-associated phenotypes is paramount to allow therapeutic development. To facilitate further studies, this review provides an overview of the known interactions of LAP1 and summarizes the evidence for the function of this protein in human health. We then review the mutations in the TOR1AIP1 gene and the clinical and pathological characteristics of subjects with these mutations. Lastly, we discuss challenges to be addressed in the future.
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Affiliation(s)
- Laurane Mackels
- MDUK Oxford Neuromuscular Center, Department of Paediatrics, University of Oxford, Oxford OX3 9DU, UK
- Adult Neurology Department, Citadelle Hospital, 4000 Liège, Belgium
| | - Xincheng Liu
- MDUK Oxford Neuromuscular Center, Department of Paediatrics, University of Oxford, Oxford OX3 9DU, UK
| | - Gisèle Bonne
- Sorbonne University, INSERM, Institut de Myologie, Centre de Recherche en Myologie, 75013 Paris, France
| | - Laurent Servais
- Neuromuscular Center, Division of Paediatrics, University Hospital of Liège, University of Liège, 4000 Liège, Belgium
- MDUK Oxford Neuromuscular Center, Department of Paediatrics, NIHR Oxford Biomedical Research Centre, University of Oxford, Oxford OX3 9DU, UK
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Zhang B, Powers JD, McCulloch AD, Chi NC. Nuclear mechanosignaling in striated muscle diseases. Front Physiol 2023; 14:1126111. [PMID: 36960155 PMCID: PMC10027932 DOI: 10.3389/fphys.2023.1126111] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Accepted: 02/22/2023] [Indexed: 03/09/2023] Open
Abstract
Mechanosignaling describes processes by which biomechanical stimuli are transduced into cellular responses. External biophysical forces can be transmitted via structural protein networks that span from the cellular membrane to the cytoskeleton and the nucleus, where they can regulate gene expression through a series of biomechanical and/or biochemical mechanosensitive mechanisms, including chromatin remodeling, translocation of transcriptional regulators, and epigenetic factors. Striated muscle cells, including cardiac and skeletal muscle myocytes, utilize these nuclear mechanosignaling mechanisms to respond to changes in their intracellular and extracellular mechanical environment and mediate gene expression and cell remodeling. In this brief review, we highlight and discuss recent experimental work focused on the pathway of biomechanical stimulus propagation at the nucleus-cytoskeleton interface of striated muscles, and the mechanisms by which these pathways regulate gene regulation, muscle structure, and function. Furthermore, we discuss nuclear protein mutations that affect mechanosignaling function in human and animal models of cardiomyopathy. Furthermore, current open questions and future challenges in investigating striated muscle nuclear mechanosignaling are further discussed.
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Affiliation(s)
- Bo Zhang
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
| | - Joseph D. Powers
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
| | - Andrew D. McCulloch
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
- Institute for Engineering in Medicine, University of California San Diego, La Jolla, CA, United States
| | - Neil C. Chi
- Department of Bioengineering, University of California San Diego, La Jolla, CA, United States
- Institute for Engineering in Medicine, University of California San Diego, La Jolla, CA, United States
- Department of Medicine, Division of Cardiovascular Medicine, University of California San Diego, La Jolla, CA, United States
- Institute of Genomic Medicine, University of California San Diego, La Jolla, CA, United States
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Du Z, Zhu T, Lin M, Bao Y, Qiao J, Lv G, Xie Y, Li Q, Quan J, Xu C, Xie Y, Wang L, Yang W, Wang S, Wu L, Yin T, Xie Y. A novel mutation in human
EMD
gene and mitochondrial dysfunction in emerin knockdown cardiomyocytes. J Cell Mol Med 2022; 26:5054-5066. [PMID: 36106556 PMCID: PMC9549503 DOI: 10.1111/jcmm.17532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Revised: 08/05/2022] [Accepted: 08/17/2022] [Indexed: 11/27/2022] Open
Abstract
Emerin is an inner nuclear envelope protein encoded by the EMD gene, mutations in which cause Emery–Dreifuss muscular dystrophy type 1 (EDMD1). Cardiac involvement has become a major threat to patients with EDMD1; however, the cardiovascular phenotype spectrums of emerinopathy and the mechanisms by which emerin regulates cardiac pathophysiology remain unclear. Here, we identified a novel nonsense mutation (c.C57G, p.Y19X) in the EMD gene in a Han Chinese family through high‐throughput sequencing. Two family members were found to have EDMD1 with muscle weakness and cardiac arrhythmia. Mechanistically, we first discovered that knockdown of emerin in HL‐1 or H9C2 cardiomyocytes lead to impaired mitochondrial oxidative phosphorylation capacity with downregulation of electron transport chain complex I and IV and upregulation of complex III and V. Moreover, loss of emerin in HL‐1 cells resulted in collapsed mitochondrial membrane potential, altered mitochondrial networks and downregulated multiple factors in RNA and protein level, such as PGC1α, DRP1, MFF, MFN2, which are involved in regulation of mitochondrial biogenesis, fission and fusion. Our findings suggest that targeting mitochondrial bioenergetics might be an effective strategy against cardiac disorders caused by EMD mutations.
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Affiliation(s)
- Zunhui Du
- Department of Cardiovascular Medicine, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Tinfang Zhu
- Department of Cardiovascular Medicine, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Menglu Lin
- Department of Cardiovascular Medicine, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Yangyang Bao
- Department of Cardiovascular Medicine, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Jing Qiao
- Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Gang Lv
- Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Yinyin Xie
- Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Qihen Li
- Department of Cardiovascular Medicine, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Jinwei Quan
- Department of Cardiovascular Medicine, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Cathy Xu
- Department of Cardiovascular Medicine, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Yuan Xie
- Johns Hopkins University Baltimore Maryland USA
| | - Lingjie Wang
- Department of Cardiovascular Medicine, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Wenjie Yang
- Department of Radiology, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Shengyue Wang
- Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Liqun Wu
- Department of Cardiovascular Medicine, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Tong Yin
- Shanghai Institute of Hematology, State Key Laboratory of Medical Genomics, National Research Center for Translational Medicine at Shanghai, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
| | - Yucai Xie
- Department of Cardiovascular Medicine, Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
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Abstract
The nuclear envelope is composed of the nuclear membranes, nuclear lamina, and nuclear pore complexes. Laminopathies are diseases caused by mutations in genes encoding protein components of the lamina and these other nuclear envelope substructures. Mutations in the single gene encoding lamin A and C, which are expressed in most differentiated somatic cells, cause diseases affecting striated muscle, adipose tissue, peripheral nerve, and multiple systems with features of accelerated aging. Mutations in genes encoding other nuclear envelope proteins also cause an array of diseases that selectively affect different tissues or organs. In some instances, the molecular and cellular consequences of laminopathy-causing mutations are known. However, even when these are understood, mechanisms explaining specific tissue or organ pathology remain enigmatic. Current mechanistic hypotheses focus on how alterations in the nuclear envelope may affect gene expression, including via the regulation of signaling pathways, or cellular mechanics, including responses to mechanical stress.
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Affiliation(s)
- 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
| | - 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
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Using nuclear envelope mutations to explore age-related skeletal muscle weakness. Clin Sci (Lond) 2020; 134:2177-2187. [PMID: 32844998 PMCID: PMC7450176 DOI: 10.1042/cs20190066] [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: 04/14/2020] [Revised: 08/04/2020] [Accepted: 08/17/2020] [Indexed: 12/19/2022]
Abstract
Skeletal muscle weakness is an important determinant of age-related declines in independence and quality of life but its causes remain unclear. Accelerated ageing syndromes such as Hutchinson-Gilford Progerin Syndrome, caused by mutations in genes encoding nuclear envelope proteins, have been extensively studied to aid our understanding of the normal biological ageing process. Like several other pathologies associated with genetic defects to nuclear envelope proteins including Emery-Dreifuss muscular dystrophy, Limb-Girdle muscular dystrophy and congenital muscular dystrophy, these disorders can lead to severe muscle dysfunction. Here, we first describe the structure and function of nuclear envelope proteins, and then review the mechanisms by which mutations in genes encoding nuclear envelope proteins induce premature ageing diseases and muscle pathologies. In doing so, we highlight the potential importance of such genes in processes leading to skeletal muscle weakness in old age.
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8
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A Novel EMD Mutation Identified by Whole-Exome Sequencing in Twins with Emery-Dreifuss Muscular Dystrophy. Case Rep Genet 2020; 2020:2071738. [PMID: 32908726 PMCID: PMC7463389 DOI: 10.1155/2020/2071738] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 08/04/2020] [Accepted: 08/13/2020] [Indexed: 01/17/2023] Open
Abstract
This case reports a novel hemizygous frameshift EMD mutation (c.487delA, p.Ser163fs) in twins of an Emery–Dreifuss muscular dystrophy family with severe cardiac involvement and mild muscle weakness. Their mother carried the same heterozygous mutation.
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9
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An Omics View of Emery-Dreifuss Muscular Dystrophy. J Pers Med 2020; 10:jpm10020050. [PMID: 32549253 PMCID: PMC7354601 DOI: 10.3390/jpm10020050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 06/08/2020] [Accepted: 06/12/2020] [Indexed: 02/06/2023] Open
Abstract
Recent progress in Omics technologies has started to empower personalized healthcare development at a thorough biomolecular level. Omics have subsidized medical breakthroughs that have started to enter clinical proceedings. The use of this scientific know-how has surfaced as a way to provide a more far-reaching view of the biological mechanisms behind diseases. This review will focus on the discoveries made using Omics and the utility of these approaches for Emery–Dreifuss muscular dystrophy.
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EDMD-Causing Emerin Mutant Myogenic Progenitors Exhibit Impaired Differentiation Using Similar Mechanisms. Cells 2020; 9:cells9061463. [PMID: 32549231 PMCID: PMC7349064 DOI: 10.3390/cells9061463] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 06/05/2020] [Accepted: 06/09/2020] [Indexed: 11/17/2022] Open
Abstract
Mutations in the gene encoding emerin (EMD) cause Emery–Dreifuss muscular dystrophy (EDMD1), an inherited disorder characterized by progressive skeletal muscle wasting, irregular heart rhythms and contractures of major tendons. The skeletal muscle defects seen in EDMD are caused by failure of muscle stem cells to differentiate and regenerate the damaged muscle. However, the underlying mechanisms remain poorly understood. Most EDMD1 patients harbor nonsense mutations and have no detectable emerin protein. There are three EDMD-causing emerin mutants (S54F, Q133H, and Δ95–99) that localize correctly to the nuclear envelope and are expressed at wildtype levels. We hypothesized these emerin mutants would share in the disruption of key molecular pathways involved in myogenic differentiation. We generated myogenic progenitors expressing wildtype emerin and each EDMD1-causing emerin mutation (S54F, Q133H, Δ95–99) in an emerin-null (EMD−/y) background. S54F, Q133H, and Δ95–99 failed to rescue EMD−/y myogenic differentiation, while wildtype emerin efficiently rescued differentiation. RNA sequencing was done to identify pathways and networks important for emerin regulation of myogenic differentiation. This analysis significantly reduced the number of pathways implicated in EDMD1 muscle pathogenesis.
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11
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Muscle cell differentiation and development pathway defects in Emery-Dreifuss muscular dystrophy. Neuromuscul Disord 2020; 30:443-456. [DOI: 10.1016/j.nmd.2020.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/20/2020] [Accepted: 04/15/2020] [Indexed: 12/12/2022]
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12
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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: 1.2] [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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Abstract
PURPOSE OF REVIEW Emery-Dreifuss muscular dystrophy (EDMD) is caused by mutations in EMD encoding emerin and LMNA encoding A-type lamins, proteins of the nuclear envelope. In the past decade, there has been an extraordinary burst of research on the nuclear envelope. Discoveries resulting from this basic research have implications for better understanding the pathogenesis and developing treatments for EDMD. RECENT FINDINGS Recent clinical research has confirmed that EDMD is one of several overlapping skeletal muscle phenotypes that can result from mutations in EMD and LMNA with dilated cardiomyopathy as a common feature. Basic research on the nuclear envelope has provided new insights into how A-type lamins and emerin function in force transmission throughout the cell, which may be particularly important in striated muscle. Much of the recent research has focused on the heart and LMNA mutations. Prevalence and outcome studies have confirmed the relative severity of cardiac disease. Robust mouse models of EDMD caused by LMNA mutations has allowed for further insight into pathogenic mechanisms and potentially beneficial therapeutic approaches. SUMMARY Recent clinical and basic research on EDMD is gradually being translated to clinical practice and possibly novel therapies.
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14
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Dai X, Zheng C, Chen X, Tang Y, Zhang H, Yan C, Ma H, Li X. Targeted next-generation sequencing identified a known EMD mutation in a Chinese patient with Emery-Dreifuss muscular dystrophy. Hum Genome Var 2019; 6:42. [PMID: 31645980 PMCID: PMC6804839 DOI: 10.1038/s41439-019-0072-8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Revised: 07/22/2019] [Accepted: 07/22/2019] [Indexed: 02/07/2023] Open
Abstract
Emery-Dreifuss muscular dystrophy (EDMD) is a rare X-linked recessive disease characterized by the clinical triad of early childhood joint contractures, progressive weakness in muscles and cardiac involvement and can result in sudden death. Targeted next-generation sequencing was performed for a Chinese patient with EDMD and the previously reported mutation [NM_000117.2: c.251_255del (p.Leu84Profs*7)] in exon 3 of the emerin gene (EMD) was identified.
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Affiliation(s)
- Xiafei Dai
- 1School of Medicine, University of Electronic Science and Technology of China, 610072 Chengdu, Sichuan China.,2Department of Cardiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, 610072 Chengdu, Sichuan China
| | - Chenqing Zheng
- Shenzhen RealOmics (Biotech) Co., Ltd., 518081 Shenzhen, China
| | - Xuepin Chen
- 2Department of Cardiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, 610072 Chengdu, Sichuan China.,4ZunYi Medical University, 563000 Zunyi, Guizhou China
| | - Yibin Tang
- 2Department of Cardiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, 610072 Chengdu, Sichuan China
| | - Hongmei Zhang
- 2Department of Cardiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, 610072 Chengdu, Sichuan China
| | - Chao Yan
- 1School of Medicine, University of Electronic Science and Technology of China, 610072 Chengdu, Sichuan China.,2Department of Cardiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, 610072 Chengdu, Sichuan China
| | - Huihui Ma
- 1School of Medicine, University of Electronic Science and Technology of China, 610072 Chengdu, Sichuan China.,2Department of Cardiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, 610072 Chengdu, Sichuan China
| | - Xiaoping Li
- 1School of Medicine, University of Electronic Science and Technology of China, 610072 Chengdu, Sichuan China.,2Department of Cardiology, Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, 610072 Chengdu, Sichuan China
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15
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Wada E, Kato M, Yamashita K, Kokuba H, Liang WC, Bonne G, Hayashi YK. Deficiency of emerin contributes differently to the pathogenesis of skeletal and cardiac muscles in LmnaH222P/H222P mutant mice. PLoS One 2019; 14:e0221512. [PMID: 31430335 PMCID: PMC6701770 DOI: 10.1371/journal.pone.0221512] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2019] [Accepted: 08/08/2019] [Indexed: 11/18/2022] Open
Abstract
Laminopathies are tissue-selective diseases that affect differently in organ systems. Mutations in nuclear envelopes, emerin (Emd) and lamin A/C (Lmna) genes, cause clinically indistinguishable myopathy called Emery-Dreifuss muscular dystrophy (EDMD) and limb-girdle muscular dystrophy. Several murine models for EDMD have been generated; however, emerin-null (Emd) mice do not show obvious skeletal and cardiac muscle phenotypes, and Lmna H222P/H222P mutant (H222P) mice show only a mild phenotype in skeletal muscle when they already have severe cardiomyopathy. Thus, the underlying molecular mechanism of muscle involvement due to nuclear abnormalities is still unclarified. We generated double mutant (Emd-/-/LmnaH222P/H222P; EH) mice to characterize dystrophic changes and to elucidate interactions between emerin and lamin A/C in skeletal and cardiac muscles. As H222P mice, EH mice grow normally and have breeding productivity. EH mice showed severer muscle involvement compared with that of H222P mice which was an independent of cardiac abnormality at 12 weeks of age. Nuclear abnormalities, reduced muscle fiber size and increased fibrosis were prominent in EH mice. Roles of emerin and lamin A/C in satellite cells function and regeneration of muscle fiber were also evaluated by cardiotoxin-induced muscle injury. Delayed increases in myog and myh3 expression were seen in both H222P and EH mice; however, the expression levels of those genes were similar with control and regenerated muscle fiber size was not different at day 7 after injury. These results indicate that EH mouse is a suitable model for studying skeletal muscle involvement, independent of cardiac function, in laminopathies and an interaction between emerin and lamin A/C in different tissues.
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Affiliation(s)
- Eiji Wada
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Megumi Kato
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Kaori Yamashita
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
| | - Hiroko Kokuba
- Institute of Medical Science, Tokyo Medical University, Tokyo, Japan
| | - Wen-Chen Liang
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Pediatrics, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Gisèle Bonne
- Sorbonne Université, Inserm UMRS 974, Center of Research in Myology, Paris, France
| | - Yukiko K. Hayashi
- Department of Pathophysiology, Tokyo Medical University, Tokyo, Japan
- * E-mail:
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16
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Wang Y, Shin JY, Nakanishi K, Homma S, Kim GJ, Tanji K, Joseph LC, Morrow JP, Stewart CL, Dauer WT, Worman HJ. Postnatal development of mice with combined genetic depletions of lamin A/C, emerin and lamina-associated polypeptide 1. Hum Mol Genet 2019; 28:2486-2500. [PMID: 31009944 DOI: 10.1093/hmg/ddz082] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 03/28/2019] [Accepted: 04/15/2019] [Indexed: 01/18/2023] Open
Abstract
Mutations in LMNA encoding lamin A/C and EMD encoding emerin cause cardiomyopathy and muscular dystrophy. Lmna null mice develop these disorders and have a lifespan of 7-8 weeks. Emd null mice show no overt pathology and have normal skeletal muscle but with regeneration defects. We generated mice with germline deletions of both Lmna and Emd to determine the effects of combined loss of the encoded proteins. Mice without lamin A/C and emerin are born at the expected Mendelian ratio, are grossly normal at birth but have shorter lifespans than those lacking only lamin A/C. However, there are no major differences between these mice with regards to left ventricular function, heart ultrastructure or electrocardiographic parameters except for slower heart rates in the mice lacking both lamin A/C and emerin. Skeletal muscle is similarly affected in both of these mice. Lmna+/- mice also lacking emerin live to at least 1 year and have no significant differences in growth, heart or skeletal muscle compared to Lmna+/- mice. Deletion of the mouse gene encoding lamina-associated protein 1 leads to prenatal death; however, mice with heterozygous deletion of this gene lacking both lamin A/C and emerin are born at the expected Mendelian ratio but had a shorter lifespan than those only lacking lamin A/C and emerin. These results show that mice with combined deficiencies of three interacting nuclear envelope proteins have normal embryonic development and that early postnatal defects are primarily driven by loss of lamin A/C or lamina-associated polypeptide 1 rather than emerin.
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Affiliation(s)
- Yuexia Wang
- Department of Medicine and.,Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, 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, USA
| | | | | | | | - Kurenai Tanji
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | | | | | - Colin L Stewart
- Development and Regenerative Biology Group, Institute of Medical Biology, Immunos, Singapore
| | - Willian T Dauer
- Department of Neurology.,Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Howard J Worman
- Department of Medicine and.,Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
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17
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Östlund C, Chang W, Gundersen GG, Worman HJ. Pathogenic mutations in genes encoding nuclear envelope proteins and defective nucleocytoplasmic connections. Exp Biol Med (Maywood) 2019; 244:1333-1344. [PMID: 31299860 DOI: 10.1177/1535370219862243] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Mutations in genes encoding nuclear lamins and associated nuclear envelope proteins have been linked to a broad range of inherited diseases affecting different tissues and organs. These diseases are often referred to as laminopathies. Scientists have yet to elucidate exactly how pathogenic mutations leading to alteration of a nuclear envelope protein cause disease. Our relatively recent research has shown that pathogenic mutations in genes encoding nuclear envelope proteins lead to defective nucleocytoplasmic connections that disrupt proper functioning of the linker of nucleoskeleton and cytoskeleton complex in the establishment of cell polarity. These defects may explain, at least in part, pathogenic mechanisms underlying laminopathies.Impact statementMutations in genes encoding nuclear lamins and associated nuclear envelope proteins have been linked to several diseases affecting different tissues and organs. The pathogenic mechanisms underlying these diseases, often called laminopathies, remain poorly understood. Increased knowledge of the functions of different nuclear envelope proteins and the interactions between them is crucial to elucidate these disease mechanisms. Our research has shown that pathogenic mutations in genes encoding nuclear envelope proteins lead to defective nucleocytoplasmic connections that disrupt proper functioning of the linker of nucleoskeleton and cytoskeleton (LINC) complex in the establishment of cell polarity. These defects may contribute to the pathogenesis of laminopathies and provide novel targets for therapeutics.
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Affiliation(s)
- Cecilia Östlund
- Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.,Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Wakam Chang
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Gregg G Gundersen
- Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
| | - Howard J Worman
- Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA.,Department of Pathology and Cell Biology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY 10032, USA
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18
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Mikulski P, Hohenstatt ML, Farrona S, Smaczniak C, Stahl Y, Kaufmann K, Angenent G, Schubert D. The Chromatin-Associated Protein PWO1 Interacts with Plant Nuclear Lamin-like Components to Regulate Nuclear Size. THE PLANT CELL 2019; 31:1141-1154. [PMID: 30914470 PMCID: PMC6533023 DOI: 10.1105/tpc.18.00663] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 02/27/2019] [Accepted: 03/22/2019] [Indexed: 05/23/2023]
Abstract
Spatial organization of chromatin contributes to gene regulation of many cellular processes and includes a connection of chromatin with the nuclear lamina (NL). The NL is a protein mesh that resides underneath the inner nuclear membrane and consists of lamins and lamina-associated proteins. Chromatin regions associated with lamins in animals are characterized mostly by constitutive heterochromatin, but association with facultative heterochromatin mediated by Polycomb-group (PcG) proteins has been reported as well. In contrast with animals, plant NL components are largely not conserved and NL association with chromatin is poorly explored. Here, we present the connection between the lamin-like protein, CROWDED NUCLEI1 (CRWN1), and the chromatin- and PcG-associated component, PROLINE-TRYPTOPHANE-TRYPTOPHANE-PROLINE INTERACTOR OF POLYCOMBS1, in Arabidopsis (Arabidopsis thaliana). We show that PWO1 and CRWN1 proteins associate physically with each other, act in the same pathway to maintain nuclear morphology, and control expression of a similar set of target genes. Moreover, we demonstrate that transiently expressed PWO1 proteins form foci located partially at the subnuclear periphery. Ultimately, as CRWN1 and PWO1 are plant-specific, our results argue that plants might have developed an equivalent, rather than homologous, mechanism of linking chromatin repression and NL.
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Affiliation(s)
- Pawel Mikulski
- Institute for Biology, Freie Universität Berlin, Berlin 14195, Germany
- Institute for Biology, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Mareike L Hohenstatt
- Institute for Biology, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Sara Farrona
- Institute for Biology, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Cezary Smaczniak
- Institute for Biology, Humboldt-University Berlin, Berlin 10115, Germany
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6700 AP, The Netherlands
| | - Yvonne Stahl
- Institute for Biology, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
| | - Kerstin Kaufmann
- Institute for Biology, Humboldt-University Berlin, Berlin 10115, Germany
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6700 AP, The Netherlands
| | - Gerco Angenent
- Laboratory of Molecular Biology, Wageningen University, Wageningen 6700 AP, The Netherlands
| | - Daniel Schubert
- Institute for Biology, Freie Universität Berlin, Berlin 14195, Germany
- Institute for Biology, Heinrich-Heine-University Düsseldorf, Düsseldorf 40225, Germany
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19
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Dubińska-Magiera M, Kozioł K, Machowska M, Piekarowicz K, Filipczak D, Rzepecki R. Emerin Is Required for Proper Nucleus Reassembly after Mitosis: Implications for New Pathogenetic Mechanisms for Laminopathies Detected in EDMD1 Patients. Cells 2019; 8:E240. [PMID: 30871242 PMCID: PMC6468536 DOI: 10.3390/cells8030240] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/26/2019] [Accepted: 03/05/2019] [Indexed: 12/29/2022] Open
Abstract
Emerin is an essential LEM (LAP2, Emerin, MAN1) domain protein in metazoans and an integral membrane protein associated with inner and outer nuclear membranes. Mutations in the human EMD gene coding for emerin result in the rare genetic disorder: Emery⁻Dreifuss muscular dystrophy type 1 (EDMD1). This disease belongs to a broader group called laminopathies-a heterogeneous group of rare genetic disorders affecting tissues of mesodermal origin. EDMD1 phenotype is characterized by progressive muscle wasting, contractures of the elbow and Achilles tendons, and cardiac conduction defects. Emerin is involved in many cellular and intranuclear processes through interactions with several partners: lamins; barrier-to-autointegration factor (BAF), β-catenin, actin, and tubulin. Our study demonstrates the presence of the emerin fraction which associates with mitotic spindle microtubules and centrosomes during mitosis and colocalizes during early mitosis with lamin A/C, BAF, and membranes at the mitotic spindle. Transfection studies with cells expressing EGFP-emerin protein demonstrate that the emerin fusion protein fraction also localizes to centrosomes and mitotic spindle microtubules during mitosis. Transient expression of emerin deletion mutants revealed that the resulting phenotypes vary and are mutant dependent. The most frequent phenotypes include aberrant nuclear shape, tubulin network mislocalization, aberrant mitosis, and mislocalization of centrosomes. Emerin deletion mutants demonstrated different chromatin binding capacities in an in vitro nuclear assembly assay and chromatin-binding properties correlated with the strength of phenotypic alteration in transfected cells. Aberrant tubulin staining and microtubule network phenotype appearance depended on the presence of the tubulin binding region in the expressed deletion mutants. We believe that the association with tubulin might help to "deliver" emerin and associated membranes to decondensing chromatin. Preliminary analyses of cells from Polish patients with EDMD1 revealed that for several mutations thought to be null for emerin protein, a truncated emerin protein was present. We infer that the EDMD1 phenotype may be strengthened by the toxicity of truncated emerin expressed in patients with certain nonsense mutations in EMD.
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Affiliation(s)
- Magda Dubińska-Magiera
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland.
- Department of Animal Developmental Biology, Institute of Experimental Biology, University of Wroclaw, Sienkiewicza 21, 50-335 Wroclaw, Poland.
| | - Katarzyna Kozioł
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland.
| | - Magdalena Machowska
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland.
| | - Katarzyna Piekarowicz
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland.
| | - Daria Filipczak
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland.
| | - Ryszard Rzepecki
- Laboratory of Nuclear Proteins, Faculty of Biotechnology, University of Wroclaw, Fryderyka Joliot-Curie 14a, 50-383 Wroclaw, Poland.
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20
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Hah J, Kim DH. Deciphering Nuclear Mechanobiology in Laminopathy. Cells 2019; 8:E231. [PMID: 30862117 PMCID: PMC6468464 DOI: 10.3390/cells8030231] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 02/23/2019] [Accepted: 03/05/2019] [Indexed: 12/13/2022] Open
Abstract
Extracellular mechanical stimuli are translated into biochemical signals inside the cell via mechanotransduction. The nucleus plays a critical role in mechanoregulation, which encompasses mechanosensing and mechanotransduction. The nuclear lamina underlying the inner nuclear membrane not only maintains the structural integrity, but also connects the cytoskeleton to the nuclear envelope. Lamin mutations, therefore, dysregulate the nuclear response, resulting in abnormal mechanoregulations, and ultimately, disease progression. Impaired mechanoregulations even induce malfunction in nuclear positioning, cell migration, mechanosensation, as well as differentiation. To know how to overcome laminopathies, we need to understand the mechanisms of laminopathies in a mechanobiological way. Recently, emerging studies have demonstrated the varying defects from lamin mutation in cellular homeostasis within mechanical surroundings. Therefore, this review summarizes recent findings highlighting the role of lamins, the architecture of nuclear lamina, and their disease relevance in the context of nuclear mechanobiology. We will also provide an overview of the differentiation of cellular mechanics in laminopathy.
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Affiliation(s)
- Jungwon Hah
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Korea.
| | - Dong-Hwee Kim
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Korea.
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21
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Brull A, Morales Rodriguez B, Bonne G, Muchir A, Bertrand AT. The Pathogenesis and Therapies of Striated Muscle Laminopathies. Front Physiol 2018; 9:1533. [PMID: 30425656 PMCID: PMC6218675 DOI: 10.3389/fphys.2018.01533] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 10/11/2018] [Indexed: 01/04/2023] Open
Abstract
Emery-Dreifuss muscular dystrophy (EDMD) is a genetic condition characterized by early contractures, skeletal muscle weakness, and cardiomyopathy. During the last 20 years, various genetic approaches led to the identification of causal genes of EDMD and related disorders, all encoding nuclear envelope proteins. By their respective localization either at the inner nuclear membrane or the outer nuclear membrane, these proteins interact with each other and establish a connection between the nucleus and the cytoskeleton. Beside this physical link, these proteins are also involved in mechanotransduction, responding to environmental cues, such as increased tension of the cytoskeleton, by the activation or repression of specific sets of genes. This ability of cells to adapt to environmental conditions is altered in EDMD. Increased knowledge on the pathophysiology of EDMD has led to the development of drug or gene therapies that have been tested on mouse models. This review proposed an overview of the functions played by the different proteins involved in EDMD and related disorders and the current therapeutic approaches tested so far.
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Affiliation(s)
- Astrid Brull
- Sorbonne Université, INSERM, Institut de Myologie, Center of Research in Myology, UMRS 974, Paris, France
| | - Blanca Morales Rodriguez
- Sorbonne Université, INSERM, Institut de Myologie, Center of Research in Myology, UMRS 974, Paris, France.,Sanofi R&D, Chilly Mazarin, France
| | - Gisèle Bonne
- Sorbonne Université, INSERM, Institut de Myologie, Center of Research in Myology, UMRS 974, Paris, France
| | - Antoine Muchir
- Sorbonne Université, INSERM, Institut de Myologie, Center of Research in Myology, UMRS 974, Paris, France
| | - Anne T Bertrand
- Sorbonne Université, INSERM, Institut de Myologie, Center of Research in Myology, UMRS 974, Paris, France
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22
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Kang SM, Yoon MH, Park BJ. Laminopathies; Mutations on single gene and various human genetic diseases. BMB Rep 2018; 51:327-337. [PMID: 29764566 PMCID: PMC6089866 DOI: 10.5483/bmbrep.2018.51.7.113] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2018] [Indexed: 01/13/2023] Open
Abstract
Lamin A and its alternative splicing product Lamin C are the key intermediate filaments (IFs) of the inner nuclear membrane intermediate filament. Lamin A/C forms the inner nuclear mesh with Lamin B and works as a frame with a nuclear shape. In addition to supporting the function of nucleus, nuclear lamins perform important roles such as holding the nuclear pore complex and chromatin. However, mutations on the Lamin A or Lamin B related proteins induce various types of human genetic disorders and diseases including premature aging syndromes, muscular dystrophy, lipodystrophy and neuropathy. In this review, we briefly overview the relevance of genetic mutations of Lamin A, human disorders and laminopathies. We also discuss a mouse model for genetic diseases. Finally, we describe the current treatment for laminopathies. [BMB Reports 2018; 51(7): 327-337].
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Affiliation(s)
- So-Mi Kang
- Department of Molecular Biology, College of Natural Science, Pusan National University, Busan 46241, Korea
| | - Min-Ho Yoon
- Department of Molecular Biology, College of Natural Science, Pusan National University, Busan 46241, Korea
| | - Bum-Joon Park
- Department of Molecular Biology, College of Natural Science, Pusan National University, Busan 46241, Korea
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23
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Osanai T, Tanaka M, Izumiyama K, Mikami K, Kitajima M, Tomisawa T, Magota K, Tomita H, Okumura K. Intracellular protons accelerate aging and switch on aging hallmarks in mice. J Cell Biochem 2018; 119:9825-9837. [PMID: 30129099 DOI: 10.1002/jcb.27302] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Accepted: 06/27/2018] [Indexed: 12/31/2022]
Abstract
Diet-induced metabolic acidosis is associated with the impairment of bone metabolism and an increased risk of a number of chronic noncommunicable diseases, such as type 2 diabetes mellitus and hypertension. The serum bicarbonate level is an independent predictor of chronic kidney disease progression. We investigated whether proton accelerates aging by analyzing both coupling factor 6-overexpressing transgenic (TG) and high salt-fed mice which display sustained intracellular acidosis, due to enhanced proton import through ecto-F1 Fo complex and/or reduced proton export through Na+ -K+ ATPase inhibition. Both types of mice displayed shortened lifespan and early senescence-associated phenotypes such as signs of hair greying and alopecia, weight loss, and/or reduced organ mass. In chronic intracellular acidosis mice, autophagy was impaired by regression of Atg7, an increase in nuclear acetylated LC3 II, and acetylation of Atg7. The increase in histone 3 trimethylation at lysine 4 (H3K4me3) and H4K20me3 and the decrease in H3K9me3 and H3K27me3 were observed in the heart and kidney obtained from both TG and high salt-fed mice. The decrease in lamin A/C, emerin, and heterochromatin protein 1α without changes in barrier-to-autointegration factor and high-mobility group box 1 was confirmed in TG and high salt-fed mice. Suppression of nuclear histone deacetylase 3-emerin system is attributable to epigenetic regression of Atg7 and H4K5 acetylation. These findings will shed light on novel aging and impaired autophagy mechanism, and provide implications in a target for antiaging therapy.
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Affiliation(s)
- Tomohiro Osanai
- Department of Nursing Science, Hirosaki University Graduate School of Health Science, Hirosaki, Japan
| | - Makoto Tanaka
- Department of Hypertension and Stroke Internal Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Kei Izumiyama
- Department of Cardiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Kasumi Mikami
- Department of Nursing Science, Hirosaki University Graduate School of Health Science, Hirosaki, Japan
| | - Maiko Kitajima
- Department of Nursing Science, Hirosaki University Graduate School of Health Science, Hirosaki, Japan
| | - Toshiko Tomisawa
- Department of Nursing Science, Hirosaki University Graduate School of Health Science, Hirosaki, Japan
| | - Koji Magota
- Daiichi Sankyo Co, Ltd, Biologics Technology Research Laboratories Group 1, Pharmaceutical Technology Division, Gunma, Japan
| | - Hirofumi Tomita
- Department of Cardiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Ken Okumura
- Saiseikai Kumamoto Hospital, Division of Cardiology, Kumamoto, Japan
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24
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Osanai T, Tanaka M, Mikami K, Kitajima M, Magota K, Tomita H, Okumura K. Mitochondrial inhibitory factor protein 1 attenuates coupling factor 6-induced aging signal. J Cell Biochem 2018; 119:6194-6203. [PMID: 29575130 DOI: 10.1002/jcb.26828] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2017] [Accepted: 02/28/2018] [Indexed: 12/16/2022]
Abstract
Coupling factor 6 (CF6) forces a counter-clockwise rotation of plasma membrane F1 Fo complex, resulting in proton import and accelerated aging. Inhibitory factor peptide 1 (IF1) suppresses a unidirectional counter-clockwise rotation of F1 Fo complex without affecting ATP synthesis. We tested the hypothesis that IF1 may attenuate CF6-induced aging signaling in CF6-overexpressing transgenic (TG) cells. In IF1-GFP overexpressing wild type (WT) cells, the diffuse peripheral staining of tubular mitochondria was observed with a dense widely distributed network around the nucleus. In TG cells, however, the only peri-nuclear network of fragmented mitochondria was observed at 24 h, but it was developed to a widely distributed mitochondrial network of tubular mitochondria at 72 h. TG cells displayed aging hallmarks of telomere attrition, epigenetic alterations, defective proteostasis, and genomic instability with a decrease in emerin and lamin and loss of heterochromatin. IF1 induction rescued TG cells from telomere attrition, expression of genomic instability with the increase in emerin and lamin, and that of epigenetic alterations with recovery of heterochromatin. In defective proteostasis, IF1 induction restored a potent peri-nuclear staining of autolysosomes compared with the baseline weak staining. The decrease in Atg7 was restored, whereas the increase in P62 was abolished. We conclude that genetic disruption of proton signals by IF1 induction suppressed CF6-induced expression of aging hallmarks such as telomere attrition, epigenetic alterations, defective proteostasis, and genomic instability. Given the widespread biological actions of CF6, the physiological and pathological actions of IF1 may be complex.
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Affiliation(s)
- Tomohiro Osanai
- Department of Nursing Science, Hirosaki University Graduate School of Health Science, Hirosaki, Japan
| | - Makoto Tanaka
- Department of Hypertension and Stroke Internal Medicine, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Kasumi Mikami
- Department of Nursing Science, Hirosaki University Graduate School of Health Science, Hirosaki, Japan
| | - Maiko Kitajima
- Department of Nursing Science, Hirosaki University Graduate School of Health Science, Hirosaki, Japan
| | - Koji Magota
- Daiichi Sankyo Co., Ltd., Biologics Technology Research Laboratories Group1, Pharmaceutical Technology Division, 2716-1, Kurakake, Akaiwa, Chiyoda-machi, Oura-gun, Gunma, Japan
| | - Hirofumi Tomita
- Department of Cardiology, Hirosaki University Graduate School of Medicine, Hirosaki, Japan
| | - Ken Okumura
- Division of Cardiology, Saiseikai Kumamoto Hospital, Kumamoto, Japan
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25
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Linker of nucleoskeleton and cytoskeleton complex proteins in cardiomyopathy. Biophys Rev 2018; 10:1033-1051. [PMID: 29869195 PMCID: PMC6082319 DOI: 10.1007/s12551-018-0431-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 05/24/2018] [Indexed: 12/21/2022] Open
Abstract
The linker of nucleoskeleton and cytoskeleton (LINC) complex couples the nuclear lamina to the cytoskeleton. The LINC complex and its associated proteins play diverse roles in cells, ranging from genome organization, nuclear morphology, gene expression, to mechanical stability. The importance of a functional LINC complex is highlighted by the large number of mutations in genes encoding LINC complex proteins that lead to skeletal and cardiac myopathies. In this review, the structure, function, and interactions between components of the LINC complex will be described. Mutations that are known to cause cardiomyopathy in patients will be discussed alongside their respective mouse models. Furthermore, future challenges for the field and emerging technologies to investigate LINC complex function will be discussed.
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26
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Iyer A, Koch AJ, Holaska JM. Expression Profiling of Differentiating Emerin-Null Myogenic Progenitor Identifies Molecular Pathways Implicated in Their Impaired Differentiation. Cells 2017; 6:cells6040038. [PMID: 29065506 PMCID: PMC5755497 DOI: 10.3390/cells6040038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/18/2017] [Accepted: 10/18/2017] [Indexed: 11/16/2022] Open
Abstract
Mutations in the gene encoding emerin cause Emery-Dreifuss muscular dystrophy (EDMD), a disorder causing progressive skeletal muscle wasting, irregular heart rhythms and contractures of major tendons. RNA sequencing was performed on differentiating wildtype and emerin-null myogenic progenitors to identify molecular pathways implicated in EDMD, 340 genes were uniquely differentially expressed during the transition from day 0 to day 1 in wildtype cells. 1605 genes were uniquely expressed in emerin-null cells; 1706 genes were shared among both wildtype and emerin-null cells. One thousand and forty-seven transcripts showed differential expression during the transition from day 1 to day 2. Four hundred and thirty-one transcripts showed altered expression in both wildtype and emerin-null cells. Two hundred and ninety-five transcripts were differentially expressed only in emerin-null cells and 321 transcripts were differentially expressed only in wildtype cells. DAVID, STRING and Ingenuity Pathway Analysis identified pathways implicated in impaired emerin-null differentiation, including cell signaling, cell cycle checkpoints, integrin signaling, YAP/TAZ signaling, stem cell differentiation, and multiple muscle development and myogenic differentiation pathways. Functional enrichment analysis showed biological functions associated with the growth of muscle tissue and myogenesis of skeletal muscle were inhibited. The large number of differentially expressed transcripts upon differentiation induction suggests emerin functions during transcriptional reprograming of progenitors to committed myoblasts.
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Affiliation(s)
- Ashvin Iyer
- Department of Pharmaceutical Sciences, University of the Sciences, Philadelphia, PA 19104, USA.
| | - Adam J Koch
- Committee on Genetics, Genomics and Systems Biology, University of Chicago, Chicago, IL 60637, USA.
| | - James M Holaska
- Department of Biomedical Sciences, Rm 534, Cooper Medical School of Rowan University, 401 South Broadway St., Camden, NJ 08028, USA.
- Department of Pharmaceutical Sciences, University of the Sciences, Philadelphia, PA 19104, USA.
- Committee on Genetics, Genomics and Systems Biology, University of Chicago, Chicago, IL 60637, USA.
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27
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Collins CM, Ellis JA, Holaska JM. MAPK signaling pathways and HDAC3 activity are disrupted during differentiation of emerin-null myogenic progenitor cells. Dis Model Mech 2017; 10:385-397. [PMID: 28188262 PMCID: PMC5399572 DOI: 10.1242/dmm.028787] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2016] [Accepted: 02/01/2017] [Indexed: 01/28/2023] Open
Abstract
Mutations in the gene encoding emerin cause Emery–Dreifuss muscular dystrophy (EDMD). Emerin is an integral inner nuclear membrane protein and a component of the nuclear lamina. EDMD is characterized by skeletal muscle wasting, cardiac conduction defects and tendon contractures. The failure to regenerate skeletal muscle is predicted to contribute to the skeletal muscle pathology of EDMD. We hypothesize that muscle regeneration defects are caused by impaired muscle stem cell differentiation. Myogenic progenitors derived from emerin-null mice were used to confirm their impaired differentiation and analyze selected myogenic molecular pathways. Emerin-null progenitors were delayed in their cell cycle exit, had decreased myosin heavy chain (MyHC) expression and formed fewer myotubes. Emerin binds to and activates histone deacetylase 3 (HDAC3). Here, we show that theophylline, an HDAC3-specific activator, improved myotube formation in emerin-null cells. Addition of the HDAC3-specific inhibitor RGFP966 blocked myotube formation and MyHC expression in wild-type and emerin-null myogenic progenitors, but did not affect cell cycle exit. Downregulation of emerin was previously shown to affect the p38 MAPK and ERK/MAPK pathways in C2C12 myoblast differentiation. Using a pure population of myogenic progenitors completely lacking emerin expression, we show that these pathways are also disrupted. ERK inhibition improved MyHC expression in emerin-null cells, but failed to rescue myotube formation or cell cycle exit. Inhibition of p38 MAPK prevented differentiation in both wild-type and emerin-null progenitors. These results show that each of these molecular pathways specifically regulates a particular stage of myogenic differentiation in an emerin-dependent manner. Thus, pharmacological targeting of multiple pathways acting at specific differentiation stages may be a better therapeutic approach in the future to rescue muscle regeneration in vivo. Editors' choice: HDAC3, p38 MAPK and ERK signaling are altered during differentiation of myogenic progenitors lacking emerin; pharmacological activation or inhibition of these signaling proteins rescues specific stages of myogenic differentiation.
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Affiliation(s)
- Carol M Collins
- University of the Sciences, Department of Pharmaceutical Sciences, 600 S. 43rd St, Philadelphia, PA 19104, USA
| | - Joseph A Ellis
- University of the Sciences, Department of Pharmaceutical Sciences, 600 S. 43rd St, Philadelphia, PA 19104, USA
| | - James M Holaska
- University of the Sciences, Department of Pharmaceutical Sciences, 600 S. 43rd St, Philadelphia, PA 19104, USA
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Smith ER, Meng Y, Moore R, Tse JD, Xu AG, Xu XX. Nuclear envelope structural proteins facilitate nuclear shape changes accompanying embryonic differentiation and fidelity of gene expression. BMC Cell Biol 2017; 18:8. [PMID: 28088180 PMCID: PMC5237523 DOI: 10.1186/s12860-017-0125-0] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Accepted: 01/07/2017] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Nuclear size and shape are specific to a cell type, function, and location, and can serve as indicators of disease and development. We previously found that lamin A/C and associated nuclear envelope structural proteins were upregulated when murine embryonic stem (ES) cells differentiated to primitive endoderm cells. Here we further investigated the morphological changes of nuclei that accompany this differentiation. RESULTS The nuclei of undifferentiated wild type cells were found shaped as flattened, irregular ovals, whereas nuclei of Gata4-positive endoderm cells were more spherical, less flattened, and with a slightly reduced volume. The morphological change was confirmed in the trophectoderm and primitive endoderm lineages of E4.5 blastocysts, compared to larger and more irregularly shaped of the nuclei of the inner cell mass. We established ES cells genetically null for the nuclear lamina proteins lamin A/C or the inner nuclear envelope protein emerin, or compound mutant for both lamin A/C and emerin. ES cells deficient in lamin A/C differentiated to endoderm but less efficiently, and the nuclei remained flattened and failed to condense. The size and shape of emerin-deficient nuclei also remained uncondensed after treatment with RA. The emerin/lamin A/C double knockout ES cells failed to differentiate to endoderm cells, though the nuclei condensed but retained a generally flattened ellipsoid shape. Additionally, ES cells deficient for lamin A/C and/or emerin had compromised ability to undergo endoderm differentiation, where the differentiating cells often exhibited coexpression of pluripotent and differentiation markers, such as Oct3/4 and Gata4, respectively, indicating an infidelity of gene regulation. CONCLUSIONS The results suggest that changes in nuclear size and shape, which are mediated by nuclear envelope structural proteins lamin A/C and/or emerin, also impact gene regulation and lineage differentiation in early embryos. Nevertheless, mice lacking both lamin A/C and emerin were born at the expected frequency, indicating their embryonic development is completed despite the observed protein deficiency.
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Affiliation(s)
- Elizabeth R Smith
- Department of Cell Biology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Papanicolaou Building, Room 415 [M877] 1550 NW 10th Avenue, Miami, FL, 33136, USA.
| | - Yue Meng
- Department of Cell Biology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Papanicolaou Building, Room 415 [M877] 1550 NW 10th Avenue, Miami, FL, 33136, USA
| | - Robert Moore
- Department of Cell Biology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Papanicolaou Building, Room 415 [M877] 1550 NW 10th Avenue, Miami, FL, 33136, USA
| | - Jeffrey D Tse
- Department of Cell Biology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Papanicolaou Building, Room 415 [M877] 1550 NW 10th Avenue, Miami, FL, 33136, USA
| | - Arn G Xu
- Department of Cell Biology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Papanicolaou Building, Room 415 [M877] 1550 NW 10th Avenue, Miami, FL, 33136, USA
| | - Xiang-Xi Xu
- Department of Cell Biology, Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Papanicolaou Building, Room 415 [M877] 1550 NW 10th Avenue, Miami, FL, 33136, USA
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Abstract
The nucleus is separated from the cytosol by the nuclear envelope, which is a double lipid bilayer composed of the outer nuclear membrane and the inner nuclear membrane. The intermediate filament proteins lamin A, lamin B, and lamin C form a network underlying the inner nuclear membrane. This proteinaceous network provides the nucleus with its strength, rigidity, and elasticity. Positioned within the inner nuclear membrane are more than 150 inner nuclear membrane proteins, many of which interact directly with lamins and require lamins for their inner nuclear membrane localization. Inner nuclear membrane proteins and the nuclear lamins define the nuclear lamina. These inner nuclear membrane proteins have tissue-specific expression and diverse functions including regulating cytoskeletal organization, nuclear architecture, cell cycle dynamics, and genomic organization. Loss or mutations in lamins and inner nuclear membrane proteins cause a wide spectrum of diseases. Here, I will review the functions of the well-studied nuclear lamina proteins and the diseases associated with loss or mutations in these proteins. © 2016 American Physiological Society. Compr Physiol 6:1655-1674, 2016.
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Affiliation(s)
- James M. Holaska
- Department of Pharmaceutical Sciences, University of the Sciences, Philadelphia, Pennsylvania, USA
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30
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Luo M, Zhao X, Song Y, Cheng H, Zhou R. Nuclear autophagy: An evolutionarily conserved mechanism of nuclear degradation in the cytoplasm. Autophagy 2016; 12:1973-1983. [PMID: 27541589 DOI: 10.1080/15548627.2016.1217381] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Macroautophagy/autophagy is a catabolic process that is essential for cellular homeostasis. Studies on autophagic degradation of cytoplasmic components have generated interest in nuclear autophagy. Although its mechanisms and roles have remained elusive, tremendous progress has been made toward understanding nuclear autophagy. Nuclear autophagy is evolutionarily conserved in eukaryotes that may target various nuclear components through a series of processes, including nuclear sensing, nuclear export, autophagic substrate encapsulation and autophagic degradation in the cytoplasm. However, the molecular processes and regulatory mechanisms involved in nuclear autophagy remain largely unknown. Numerous studies have highlighted the importance of nuclear autophagy in physiological and pathological processes such as cancer. This review focuses on current advances in nuclear autophagy and provides a summary of its research history and landmark discoveries to offer new perspectives.
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Affiliation(s)
- Majing Luo
- a Hubei Key Laboratory of Cell Homeostasis, Laboratory of Molecular and Developmental Genetics, College of Life Sciences , Wuhan University , Wuhan , China
| | - Xueya Zhao
- a Hubei Key Laboratory of Cell Homeostasis, Laboratory of Molecular and Developmental Genetics, College of Life Sciences , Wuhan University , Wuhan , China
| | - Ying Song
- a Hubei Key Laboratory of Cell Homeostasis, Laboratory of Molecular and Developmental Genetics, College of Life Sciences , Wuhan University , Wuhan , China
| | - Hanhua Cheng
- a Hubei Key Laboratory of Cell Homeostasis, Laboratory of Molecular and Developmental Genetics, College of Life Sciences , Wuhan University , Wuhan , China
| | - Rongjia Zhou
- a Hubei Key Laboratory of Cell Homeostasis, Laboratory of Molecular and Developmental Genetics, College of Life Sciences , Wuhan University , Wuhan , China
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31
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Borsos M, Torres-Padilla ME. Building up the nucleus: nuclear organization in the establishment of totipotency and pluripotency during mammalian development. Genes Dev 2016; 30:611-21. [PMID: 26980186 PMCID: PMC4803048 DOI: 10.1101/gad.273805.115] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In mammals, epigenetic reprogramming, the acquisition and loss of totipotency, and the first cell fate decision all occur within a 3-d window after fertilization from the one-cell zygote to the formation of the blastocyst. These processes are poorly understood in molecular detail, yet this is an essential prerequisite to uncover principles of stem cells, chromatin biology, and thus regenerative medicine. A unique feature of preimplantation development is the drastic genome-wide changes occurring to nuclear architecture. From studying somatic and in vitro cultured embryonic stem cells (ESCs) it is becoming increasingly established that the three-dimensional (3D) positions of genomic loci relative to each other and to specific compartments of the nucleus can act on the regulation of gene expression, potentially driving cell fate. However, the functionality, mechanisms, and molecular characteristics of the changes in nuclear organization during preimplantation development are only now beginning to be unraveled. Here, we discuss the peculiarities of nuclear compartments and chromatin organization during mammalian preimplantation development in the context of the transition from totipotency to pluripotency.
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Affiliation(s)
- Máté Borsos
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, U964, Centre National de la Recherche Scientifique/Institut National de la Santé et de la Recherche Médicale F-67404 Illkirch, France; Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München D-81377 München, Germany
| | - Maria-Elena Torres-Padilla
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, U964, Centre National de la Recherche Scientifique/Institut National de la Santé et de la Recherche Médicale F-67404 Illkirch, France; Institute of Epigenetics and Stem Cells, Helmholtz Zentrum München D-81377 München, Germany
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32
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Barton LJ, Lovander KE, Pinto BS, Geyer PK. Drosophila male and female germline stem cell niches require the nuclear lamina protein Otefin. Dev Biol 2016; 415:75-86. [PMID: 27174470 DOI: 10.1016/j.ydbio.2016.05.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2015] [Revised: 04/28/2016] [Accepted: 05/02/2016] [Indexed: 12/11/2022]
Abstract
The nuclear lamina is an extensive protein network that underlies the inner nuclear envelope. This network includes the LAP2-emerin-MAN1-domain (LEM-D) protein family, proteins that share an association with the chromatin binding protein Barrier-to-autointegration factor (BAF). Loss of individual LEM-D proteins causes progressive, tissue-restricted diseases, known as laminopathies. Mechanisms associated with laminopathies are not yet understood. Here we present our studies of one of the Drosophila nuclear lamina LEM-D proteins, Otefin (Ote), a homologue of emerin. Previous studies have shown that Ote is autonomously required for the survival of female germline stem cells (GSCs). We demonstrate that Ote is also required for survival of somatic cells in the ovarian niche, with loss of Ote causing a decrease in cap cell number and altered signal transduction. We show germ cell-restricted expression of Ote rescues these defects, revealing a non-autonomous function for Ote in niche maintenance and emphasizing that GSCs contribute to the maintenance of their own niches. Further, we investigate the requirement of Ote in the male fertility. We show that ote mutant males become prematurely sterile as they age. Parallel to observations in females, this sterility is associated with GSC loss and changes in somatic cells of the niche, phenotypes that are largely rescued by germ cell-restricted Ote expression. Taken together, our studies demonstrate that Ote is required autonomously for survival of two stem cell populations, as well as non-autonomously for maintenance of two somatic niches. Finally, our data add to growing evidence that LEM-D proteins have critical roles in stem cell survival and tissue homeostasis.
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Affiliation(s)
- Lacy J Barton
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Kaylee E Lovander
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Belinda S Pinto
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA
| | - Pamela K Geyer
- Department of Biochemistry, University of Iowa, Iowa City, IA 52242, USA.
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33
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Wang Y, Xiao X, Wang L. Molecular characterization and expression patterns of emerin (EMD) gene in skeletal muscle between Meishan and Large White pigs. Gene 2016; 579:41-6. [PMID: 26743124 DOI: 10.1016/j.gene.2015.12.059] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 10/03/2015] [Accepted: 12/21/2015] [Indexed: 01/19/2023]
Abstract
The emerin protein is a nuclear membrane protein and has important functions in muscle development, regeneration, and cell signal transduction. However, knowledge regarding emerin in the domestic animal is limited. In this study, we cloned and characterized the pig emerin (EMD) gene. Semi-quantitative RT-PCR analysis revealed that the EMD gene was expressed at the highest level in the heart and fat at 120d. However, the fetal skeletal muscles displayed a greater abundance of EMD mRNA than that in skeletal muscles at postnatal development stages. In addition, the expression level of EMD at 60 day was significantly higher (p<0.05) in Meishan than Large White pigs. Pig EMD protein displayed the sarcolemma and perinuclear distribution in skeletal muscle sections, and there was no distribution change of EMD in skeletal muscle sections between Large White and Meishan pigs. These studies provide useful information for further research on the functions of pig EMD gene in skeletal muscle.
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Affiliation(s)
- Yan Wang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, PR China
| | - Xia Xiao
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province,Sichuan Agricultural University, Chengdu, Sichuan, PR China
| | - Linjie Wang
- College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, Sichuan, PR China; Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province,Sichuan Agricultural University, Chengdu, Sichuan, PR China.
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34
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Pfaff J, Rivera Monroy J, Jamieson C, Rajanala K, Vilardi F, Schwappach B, Kehlenbach RH. Emery-Dreifuss muscular dystrophy mutations impair TRC40-mediated targeting of emerin to the inner nuclear membrane. J Cell Sci 2015; 129:502-16. [PMID: 26675233 DOI: 10.1242/jcs.179333] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2015] [Accepted: 12/14/2015] [Indexed: 11/20/2022] Open
Abstract
Emerin is a tail-anchored protein that is found predominantly at the inner nuclear membrane (INM), where it associates with components of the nuclear lamina. Mutations in the emerin gene cause Emery-Dreifuss muscular dystrophy (EDMD), an X-linked recessive disease. Here, we report that the TRC40/GET pathway for post-translational insertion of tail-anchored proteins into membranes is involved in emerin-trafficking. Using proximity ligation assays, we show that emerin interacts with TRC40 in situ. Emerin expressed in bacteria or in a cell-free lysate was inserted into microsomal membranes in an ATP- and TRC40-dependent manner. Dominant-negative fragments of the TRC40-receptor proteins WRB and CAML (also known as CAMLG) inhibited membrane insertion. A rapamycin-based dimerization assay revealed correct transport of wild-type emerin to the INM, whereas TRC40-binding, membrane integration and INM-targeting of emerin mutant proteins that occur in EDMD was disturbed. Our results suggest that the mode of membrane integration contributes to correct targeting of emerin to the INM.
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Affiliation(s)
- Janine Pfaff
- Department of Molecular Biology, Faculty of Medicine, Georg-August-University, GZMB, Humboldtallee 23, Göttingen 37073, Germany
| | - Jhon Rivera Monroy
- Department of Molecular Biology, Faculty of Medicine, Georg-August-University, GZMB, Humboldtallee 23, Göttingen 37073, Germany
| | - Cara Jamieson
- Department of Molecular Biology, Faculty of Medicine, Georg-August-University, GZMB, Humboldtallee 23, Göttingen 37073, Germany
| | - Kalpana Rajanala
- Department of Molecular Biology, Faculty of Medicine, Georg-August-University, GZMB, Humboldtallee 23, Göttingen 37073, Germany
| | - Fabio Vilardi
- Department of Molecular Biology, Faculty of Medicine, Georg-August-University, GZMB, Humboldtallee 23, Göttingen 37073, Germany
| | - Blanche Schwappach
- Department of Molecular Biology, Faculty of Medicine, Georg-August-University, GZMB, Humboldtallee 23, Göttingen 37073, Germany Max-Planck Institute for Biophysical Chemistry, Göttingen 37077, Germany
| | - Ralph H Kehlenbach
- Department of Molecular Biology, Faculty of Medicine, Georg-August-University, GZMB, Humboldtallee 23, Göttingen 37073, Germany
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35
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Barton LJ, Soshnev AA, Geyer PK. Networking in the nucleus: a spotlight on LEM-domain proteins. Curr Opin Cell Biol 2015; 34:1-8. [PMID: 25863918 DOI: 10.1016/j.ceb.2015.03.005] [Citation(s) in RCA: 146] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 03/23/2015] [Accepted: 03/25/2015] [Indexed: 11/29/2022]
Abstract
Proteins resident in the inner nuclear membrane and underlying nuclear lamina form a network that regulates nuclear functions. This review highlights a prominent family of nuclear lamina proteins that carries the LAP2-emerin-MAN1-domain (LEM-D). LEM-D proteins share an ability to bind lamins and tether repressive chromatin at the nuclear periphery. The importance of this family is underscored by findings that loss of individual LEM-D proteins causes progressive, tissue-restricted diseases, known as laminopathies. Diverse functions of LEM-D proteins are linked to interactions with unique and overlapping partners including signal transduction effectors, transcription factors and architectural proteins. Recent investigations suggest that LEM-D proteins form hubs within the nuclear lamina that integrate external signals important for tissue homeostasis and maintenance of progenitor cell populations.
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Affiliation(s)
- Lacy J Barton
- Department of Biochemistry, University of Iowa, College of Medicine, Iowa City, IA 52242, USA; Skirball Institute, Department of Cell Biology, NYU School of Medicine, NYU Langone Medical Center, New York, NY 10016, USA
| | - Alexey A Soshnev
- Laboratory of Chromatin Biology and Epigenetics, The Rockefeller University, New York, NY, 10065, USA
| | - Pamela K Geyer
- Department of Biochemistry, University of Iowa, College of Medicine, Iowa City, IA 52242, USA.
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36
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Morales-Martínez A, Dobrzynska A, Askjaer P. Inner nuclear membrane protein LEM-2 is required for proper nuclear separation and morphology. J Cell Sci 2015; 128:1090-6. [DOI: 10.1242/jcs.164202] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
The inner nuclear membrane proteins emerin and LEMD2 have both overlapping and separate functions in regulation of nuclear organization, gene expression and cell differentiation. We report here that emerin/EMR-1 and LEMD2/LEM-2 are expressed in all tissues throughout Caenorhaditis elegans development but their relative distribution differs between cell types. The ratio between EMR-1 and LEM-2 is particularly high in contractile tissues, intermediate in neurons and hypodermis and lowest in intestine and germ line. We find that LEM-2 is recruited earlier than EMR-1 to reforming nuclear envelopes, suggesting the presence of separate mitotic membrane compartments and specific functions of each protein. Concordantly, we observe that nuclei of lem-2 mutant embryos, but not of emr-1 mutants, have reduced nuclear circularity. Finally, we uncover a novel role of LEM-2 in nuclear separation and anchoring of microtubule organizing centers.
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37
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Stubenvoll A, Rice M, Wietelmann A, Wheeler M, Braun T. Attenuation of Wnt/β-catenin activity reverses enhanced generation of cardiomyocytes and cardiac defects caused by the loss of emerin. Hum Mol Genet 2014; 24:802-13. [PMID: 25274778 DOI: 10.1093/hmg/ddu498] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Mutations in EMD, encoding emerin cause skeletal muscle and heart defects in patients with X-linked Emery-Dreifuss muscular dystrophy (X-EDMD) but the underlying mechanisms leading to cardiac defects are poorly understood. Here, we investigated the role of emerin in controlling cardiomyocyte proliferation and cardiac remodeling and explored its function in regulation of the Wnt/β-catenin pathway. We observed a remarkable increase of cardiomyocytes in emerin-null adult mice accompanied with decreased numbers of multinucleated cells. Depletion of emerin in mouse ES cell-derived cardiomyocytes by shRNA caused hyperactivation of Wnt/β-catenin signaling, increased proliferation and abrogated timely cardiac differentiation. Likewise, emerin-null mice exhibited increased Wnt/β-catenin signaling, cardiac dysfunction and perturbed hypertrophic remodeling following pressure overload. Pharmacological inhibition of β-catenin normalized proliferation and differentiation of ES cell-derived cardiomyocytes while inactivation of a single allele of β-catenin efficiently rescued cardiac dysfunction in emerin-null mice. We conclude that emerin constrains β-catenin signaling in the heart providing tight control of cardiomyocyte numbers. Enhanced Wnt/β-catenin signaling seems to contribute to cardiac defects observed in X-EDMD. Hence, therapeutic inhibition of Wnt/β-catenin signaling might be beneficial for X-EDMD patients.
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Affiliation(s)
- Alexander Stubenvoll
- Department of Cardiac Development and Remodelling, Max-Planck-Institute for Heart and Lung Research, Ludwigstraße 43, Bad Nauheim 61231, Germany
| | - Megan Rice
- Department of Cardiac Development and Remodelling, Max-Planck-Institute for Heart and Lung Research, Ludwigstraße 43, Bad Nauheim 61231, Germany
| | - Astrid Wietelmann
- Department of Cardiac Development and Remodelling, Max-Planck-Institute for Heart and Lung Research, Ludwigstraße 43, Bad Nauheim 61231, Germany
| | - Matthew Wheeler
- Department of Cardiac Development and Remodelling, Max-Planck-Institute for Heart and Lung Research, Ludwigstraße 43, Bad Nauheim 61231, Germany
| | - Thomas Braun
- Department of Cardiac Development and Remodelling, Max-Planck-Institute for Heart and Lung Research, Ludwigstraße 43, Bad Nauheim 61231, Germany
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38
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Müller TJ, Kraya T, Stoltenburg-Didinger G, Hanisch F, Kornhuber M, Stoevesandt D, Senderek J, Weis J, Baum P, Deschauer M, Zierz S. Phenotype of matrin-3-related distal myopathy in 16 German patients. Ann Neurol 2014; 76:669-80. [DOI: 10.1002/ana.24255] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2014] [Revised: 08/21/2014] [Accepted: 08/21/2014] [Indexed: 11/11/2022]
Affiliation(s)
- Tobias J. Müller
- Department of Neurology; Martin Luther University of Halle-Wittenberg; Halle Germany
| | - Torsten Kraya
- Department of Neurology; Martin Luther University of Halle-Wittenberg; Halle Germany
| | - Gisela Stoltenburg-Didinger
- Department of Neurology; Martin Luther University of Halle-Wittenberg; Halle Germany
- Institute of Cell and Neurobiology; Charité University Medicine Berlin; Berlin Germany
| | - Frank Hanisch
- Department of Neurology; Martin Luther University of Halle-Wittenberg; Halle Germany
| | - Malte Kornhuber
- Department of Neurology; Martin Luther University of Halle-Wittenberg; Halle Germany
| | - Dietrich Stoevesandt
- Department of Diagnostic Radiology; Martin Luther University of Halle-Wittenberg; Halle Germany
| | - Jan Senderek
- Friedrich Bauer Institute; Ludwig Maximilian University of Munich; Munich Germany
| | - Joachim Weis
- Institute of Neuropathology; RWTH Aachen University Hospital; Aachen Germany
| | - Petra Baum
- Clinic and Polyclinic for Neurology; University of Leipzig; Leipzig Germany
| | - Marcus Deschauer
- Department of Neurology; Martin Luther University of Halle-Wittenberg; Halle Germany
| | - Stephan Zierz
- Department of Neurology; Martin Luther University of Halle-Wittenberg; Halle Germany
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39
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Shin JY, Le Dour C, Sera F, Iwata S, Homma S, Joseph LC, Morrow JP, Dauer WT, Worman HJ. Depletion of lamina-associated polypeptide 1 from cardiomyocytes causes cardiac dysfunction in mice. Nucleus 2014; 5:260-459. [PMID: 24859316 DOI: 10.4161/nucl.29227] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
We previously showed that striated muscle-selective depletion of lamina-associated polypeptide 1 (LAP1), an integral inner nuclear membrane protein, leads to profound muscular dystrophy with premature death in mice. As LAP1 is also depleted in hearts of these mice, we examined their cardiac phenotype. Striated muscle-selective LAP1 knockout mice display ventricular systolic dysfunction with abnormal induction of genes encoding cardiomyopathy related proteins. To eliminate possible confounding effects due to skeletal muscle pathology, we generated a new mouse line in which LAP1 is deleted in a cardiomyocyte-selective manner. These mice had no skeletal muscle pathology and appeared overtly normal at 20 weeks of age. However, cardiac echocardiography revealed that they developed left ventricular systolic dysfunction and cardiac gene expression analysis revealed abnormal induction of cardiomyopathy-related genes. Our results demonstrate that LAP1 expression in cardiomyocytes is required for normal left ventricular function, consistent with a report of cardiomyopathy in a human subject with mutation in the gene encoding LAP1.
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Affiliation(s)
- Ji-Yeon Shin
- Department of Medicine; College of Physicians & Surgeons; Columbia University; New York, NY USA; Department of Pathology and Cell Biology; College of Physicians & Surgeons; Columbia University; New York, NY USA
| | - Caroline Le Dour
- Department of Medicine; College of Physicians & Surgeons; Columbia University; New York, NY USA; Department of Pathology and Cell Biology; College of Physicians & Surgeons; Columbia University; New York, NY USA
| | - Fusako Sera
- Department of Medicine; College of Physicians & Surgeons; Columbia University; New York, NY USA
| | - Shinichi Iwata
- Department of Medicine; College of Physicians & Surgeons; Columbia University; New York, NY USA
| | - Shunichi Homma
- Department of Medicine; College of Physicians & Surgeons; Columbia University; New York, NY USA
| | - Leroy C Joseph
- Department of Medicine; College of Physicians & Surgeons; Columbia University; New York, NY USA
| | - John P Morrow
- Department of Medicine; College of Physicians & Surgeons; Columbia University; New York, NY USA
| | - William T Dauer
- Department of Neurology; University of Michigan Medical School; Ann Arbor, MI USA; Department of Cell and Developmental Biology; University of Michigan Medical School; Ann Arbor, MI USA
| | - Howard J Worman
- Department of Medicine; College of Physicians & Surgeons; Columbia University; New York, NY USA; Department of Pathology and Cell Biology; College of Physicians & Surgeons; Columbia University; New York, NY USA
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Stroud MJ, Banerjee I, Veevers J, Chen J. Linker of nucleoskeleton and cytoskeleton complex proteins in cardiac structure, function, and disease. Circ Res 2014; 114:538-48. [PMID: 24481844 DOI: 10.1161/circresaha.114.301236] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The linker of nucleoskeleton and cytoskeleton (LINC) complex, composed of proteins within the inner and the outer nuclear membranes, connects the nuclear lamina to the cytoskeleton. The importance of this complex has been highlighted by the discovery of mutations in genes encoding LINC complex proteins, which cause skeletal or cardiac myopathies. Herein, this review summarizes structure, function, and interactions of major components of the LINC complex, highlights how mutations in these proteins may lead to cardiac disease, and outlines future challenges in the field.
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Affiliation(s)
- Matthew J Stroud
- From the Department of Cardiology, University of California San Diego School of Medicine, La Jolla, CA
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Shin JY, Dauer WT, Worman HJ. Lamina-associated polypeptide 1: protein interactions and tissue-selective functions. Semin Cell Dev Biol 2014; 29:164-8. [PMID: 24508913 DOI: 10.1016/j.semcdb.2014.01.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 12/27/2013] [Accepted: 01/28/2014] [Indexed: 01/25/2023]
Abstract
Mutations in genes encoding widely expressed nuclear envelope proteins often lead to diseases that manifest in specific tissues. Lamina-associated polypeptide 1 (LAP1) is an integral protein of the inner nuclear membrane that is expressed in most cells and tissues. Within the nuclear envelope, LAP1 interacts physically with lamins, torsinA and emerin, suggesting it may serve as a key node for transducing signals across the inner nuclear membrane. Indeed, recent in vivo studies in genetically modified mice strongly support functional links between LAP1 and both torsinA (in neurons) and emerin (in muscle). These studies suggest that tissue-selective diseases caused by mutations in genes encoding nuclear envelope proteins may result, at least in part, from the selective disruption of discrete nuclear envelope protein complexes.
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Affiliation(s)
- Ji-Yeon Shin
- Department of Medicine, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY, 10032, USA; Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY, 10032, USA
| | - William T Dauer
- Department of Neurology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI, 48109, USA; Department of Cell and Developmental Biology, University of Michigan Medical School, 109 Zina Pitcher Place, Ann Arbor, MI, 48109, USA.
| | - Howard J Worman
- Department of Medicine, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY, 10032, USA; Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, 630 West 168th Street, New York, NY, 10032, USA.
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Genome-wide analysis links emerin to neuromuscular junction activity in Caenorhabditis elegans. Genome Biol 2014; 15:R21. [PMID: 24490688 PMCID: PMC4053756 DOI: 10.1186/gb-2014-15-2-r21] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2013] [Accepted: 02/03/2014] [Indexed: 01/01/2023] Open
Abstract
Background Laminopathies are diseases characterized by defects in nuclear envelope structure. A well-known example is Emery-Dreifuss muscular dystrophy, which is caused by mutations in the human lamin A/C and emerin genes. While most nuclear envelope proteins are ubiquitously expressed, laminopathies often affect only a subset of tissues. The molecular mechanisms underlying these tissue-specific manifestations remain elusive. We hypothesize that different functional subclasses of genes might be differentially affected by defects in specific nuclear envelope components. Results Here we determine genome-wide DNA association profiles of two nuclear envelope components, lamin/LMN-1 and emerin/EMR-1 in adult Caenorhabditis elegans. Although both proteins bind to transcriptionally inactive regions of the genome, EMR-1 is enriched at genes involved in muscle and neuronal function. Deletion of either EMR-1 or LEM-2, another integral envelope protein, causes local changes in nuclear architecture as evidenced by altered association between DNA and LMN-1. Transcriptome analyses reveal that EMR-1 and LEM-2 are associated with gene repression, particularly of genes implicated in muscle and nervous system function. We demonstrate that emr-1, but not lem-2, mutants are sensitive to the cholinesterase inhibitor aldicarb, indicating altered activity at neuromuscular junctions. Conclusions We identify a class of elements that bind EMR-1 but do not associate with LMN-1, and these are enriched for muscle and neuronal genes. Our data support a redundant function of EMR-1 and LEM-2 in chromatin anchoring to the nuclear envelope and gene repression. We demonstrate a specific role of EMR-1 in neuromuscular junction activity that may contribute to Emery-Dreifuss muscular dystrophy in humans.
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Abstract
In eukaryotes, the function of the cell's nucleus has primarily been considered to be the repository for the organism's genome. However, this rather simplistic view is undergoing a major shift, as it is increasingly apparent that the nucleus has functions extending beyond being a mere genome container. Recent findings have revealed that the structural composition of the nucleus changes during development and that many of these components exhibit cell- and tissue-specific differences. Increasing evidence is pointing to the nucleus being integral to the function of the interphase cytoskeleton, with changes to nuclear structural proteins having ramifications affecting cytoskeletal organization and the cell's interactions with the extracellular environment. Many of these functions originate at the nuclear periphery, comprising the nuclear envelope (NE) and underlying lamina. Together, they may act as a "hub" in integrating cellular functions including chromatin organization, transcriptional regulation, mechanosignaling, cytoskeletal organization, and signaling pathways. Interest in such an integral role has been largely stimulated by the discovery that many diseases and anomalies are caused by defects in proteins of the NE/lamina, the nuclear envelopathies, many of which, though rare, are providing insights into their more common variants that are some of the major issues of the twenty-first century public health. Here, we review the contributions that mouse mutants have made to our current understanding of the NE/lamina, their respective roles in disease and the use of mice in developing potential therapies for treating the diseases.
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Koch AJ, Holaska JM. Emerin in health and disease. Semin Cell Dev Biol 2013; 29:95-106. [PMID: 24365856 DOI: 10.1016/j.semcdb.2013.12.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 12/02/2013] [Accepted: 12/15/2013] [Indexed: 12/27/2022]
Abstract
Emery-Dreifuss muscular dystrophy (EDMD) is caused by mutations in the genes encoding emerin, lamins A and C and FHL1. Additional EDMD-like syndromes are caused by mutations in nesprins and LUMA. This review will specifically focus on emerin function and the current thinking for how loss or mutations in emerin cause EDMD. Emerin is a well-conserved, ubiquitously expressed protein of the inner nuclear membrane. Emerin has been shown to have diverse functions, including the regulation of gene expression, cell signaling, nuclear structure and chromatin architecture. This review will focus on the relationships between these functions and the EDMD disease phenotype. Additionally it will highlight open questions concerning emerin's roles in cell and nuclear biology and disease.
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Affiliation(s)
- Adam J Koch
- Committee on Genetics, Genomics and Systems Biology, The University of Chicago, Chicago, IL 60637, USA.
| | - James M Holaska
- Committee on Genetics, Genomics and Systems Biology, The University of Chicago, Chicago, IL 60637, USA; Committee on Developmental, Regeneration and Stem Cell Biology, The University of Chicago, Chicago, IL 60637, USA.
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45
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Folker ES, Baylies MK. Nuclear positioning in muscle development and disease. Front Physiol 2013; 4:363. [PMID: 24376424 PMCID: PMC3859928 DOI: 10.3389/fphys.2013.00363] [Citation(s) in RCA: 190] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 11/23/2013] [Indexed: 11/13/2022] Open
Abstract
Muscle disease as a group is characterized by muscle weakness, muscle loss, and impaired muscle function. Although the phenotype is the same, the underlying cellular pathologies, and the molecular causes of these pathologies, are diverse. One common feature of many muscle disorders is the mispositioning of myonuclei. In unaffected individuals, myonuclei are spaced throughout the periphery of the muscle fiber such that the distance between nuclei is maximized. However, in diseased muscles, the nuclei are often clustered within the center of the muscle cell. Although this phenotype has been acknowledged for several decades, it is often ignored as a contributor to muscle weakness. Rather, these nuclei are taken only as a sign of muscle repair. Here we review the evidence that mispositioned myonuclei are not merely a symptom of muscle disease but also a cause. Additionally, we review the working models for how myonuclei move from two different perspectives: from that of the nuclei and from that of the cytoskeleton. We further compare and contrast these mechanisms with the mechanisms of nuclear movement in other cell types both to draw general themes for nuclear movement and to identify muscle-specific considerations. Finally, we focus on factors that can be linked to muscle disease and find that genes that regulate myonuclear movement and positioning have been linked to muscular dystrophy. Although the cause-effect relationship is largely speculative, recent data indicate that the position of nuclei should no longer be considered only a means to diagnose muscle disease.
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Affiliation(s)
- Eric S Folker
- Department of Biology, Boston College Chestnut Hill, MA, USA
| | - Mary K Baylies
- Department of Developmental Biology, Sloan-Kettering Institute New York, NY, USA
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46
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Chang W, Folker ES, Worman HJ, Gundersen GG. Emerin organizes actin flow for nuclear movement and centrosome orientation in migrating fibroblasts. Mol Biol Cell 2013; 24:3869-80. [PMID: 24152738 PMCID: PMC3861083 DOI: 10.1091/mbc.e13-06-0307] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Emerin, a nuclear membrane protein, and myosin IIB contribute to nuclear movement by regulating the directionality of nuclear movement and dorsal actin cable flow. Emerin interacts with myosin IIB and is required for its perinuclear localization. The results show that the nuclear envelope actively organizes cytoplasmic polarity. In migrating fibroblasts, rearward movement of the nucleus orients the centrosome toward the leading edge. Nuclear movement results from coupling rearward-moving, dorsal actin cables to the nucleus by linear arrays of nesprin-2G and SUN2, termed transmembrane actin-associated nuclear (TAN) lines. A-type lamins anchor TAN lines, prompting us to test whether emerin, a nuclear membrane protein that interacts with lamins and TAN line proteins, contributes to nuclear movement. In fibroblasts depleted of emerin, nuclei moved nondirectionally or completely failed to move. Consistent with these nuclear movement defects, dorsal actin cable flow was nondirectional in cells lacking emerin. TAN lines formed normally in cells lacking emerin and were coordinated with the erratic nuclear movements, although in 20% of the cases, TAN lines slipped over immobile nuclei. Myosin II drives actin flow, and depletion of myosin IIB, but not myosin IIA, showed similar nondirectional nuclear movement and actin flow as in emerin-depleted cells. Myosin IIB specifically coimmunoprecipitated with emerin, and emerin depletion prevented myosin IIB localization near nuclei. These results show that emerin functions with myosin IIB to polarize actin flow and nuclear movement in fibroblasts, suggesting a novel function for the nuclear envelope in organizing directional actin flow and cytoplasmic polarity.
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Affiliation(s)
- Wakam Chang
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032 Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032
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Shin JY, Méndez-López I, Wang Y, Hays AP, Tanji K, Lefkowitch JH, Schulze PC, Worman HJ, Dauer WT. Lamina-associated polypeptide-1 interacts with the muscular dystrophy protein emerin and is essential for skeletal muscle maintenance. Dev Cell 2013; 26:591-603. [PMID: 24055652 DOI: 10.1016/j.devcel.2013.08.012] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2012] [Revised: 06/13/2013] [Accepted: 08/15/2013] [Indexed: 12/30/2022]
Abstract
X-linked Emery-Dreifuss muscular dystrophy is caused by loss of function of emerin, an integral protein of the inner nuclear membrane. Yet emerin null mice are essentially normal, suggesting the existence of a critical compensating factor. We show that the lamina-associated polypeptide1 (LAP1) interacts with emerin. Conditional deletion of LAP1 from striated muscle causes muscular dystrophy; this pathology is worsened in the absence of emerin. LAP1 levels are significantly higher in mouse than human skeletal muscle, and reducing LAP1 by approximately half in mice also induces muscle abnormalities in emerin null mice. Conditional deletion of LAP1 from hepatocytes yields mice that exhibit normal liver function and are indistinguishable from littermate controls. These results establish that LAP1 interacts physically and functionally with emerin and plays an essential and selective role in skeletal muscle maintenance. They also highlight how dissecting differences between mouse and human phenotypes can provide fundamental insights into disease mechanisms.
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Affiliation(s)
- Ji-Yeon Shin
- Department of Medicine, College of Physicians and Surgeons, Columbia University, 630 West 168(th) Street, New York, NY 10032, USA; Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, 630 West 168(th) Street, New York, NY 10032, USA
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Abstract
Emerin, a conserved LEM-domain protein, is among the few nuclear membrane proteins for which extensive basic knowledge—biochemistry, partners, functions, localizations, posttranslational regulation, roles in development and links to human disease—is available. This review summarizes emerin and its emerging roles in nuclear “lamina” structure, chromatin tethering, gene regulation, mitosis, nuclear assembly, development, signaling and mechano-transduction. We also highlight many open questions, exploration of which will be critical to understand how this intriguing nuclear membrane protein and its “family” influence the genome.
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Affiliation(s)
- Jason M Berk
- Department of Cell Biology; Johns Hopkins University School of Medicine; Baltimore, MD USA
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Pilat U, Dechat T, Bertrand AT, Woisetschläger N, Gotic I, Spilka R, Biadasiewicz K, Bonne G, Foisner R. The muscle dystrophy-causing ΔK32 lamin A/C mutant does not impair the functions of the nucleoplasmic lamin-A/C-LAP2α complex in mice. J Cell Sci 2013; 126:1753-62. [PMID: 23444379 DOI: 10.1242/jcs.115246] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
A-type lamins are components of the nuclear lamina, a filamentous network of the nuclear envelope in metazoans that supports nuclear architecture. In addition, lamin A/C can also be found in the interior of the nucleus. This nucleoplasmic lamin pool is soluble in physiological buffer, depends on the presence of the lamin-binding protein, lamina-associated polypeptide 2α (LAP2α) and regulates cell cycle progression in tissue progenitor cells. ΔK32 mutations in A-type lamins cause severe congenital muscle disease in humans and a muscle maturation defect in Lmna(ΔK32/ΔK32) knock-in mice. Mutant ΔK32 lamin A/C protein levels were reduced and all mutant lamin A/C was soluble and mislocalized to the nucleoplasm. To test the role of LAP2α in nucleoplasmic ΔK32 lamin A/C regulation and functions, we deleted LAP2α in Lmna(ΔK32/ΔK32) knock-in mice. In double mutant mice the Lmna(ΔK32/ΔK32)-linked muscle defect was unaffected. LAP2α interacted with mutant lamin A/C, but unlike wild-type lamin A/C, the intranuclear localization of ΔK32 lamin A/C was not affected by loss of LAP2α. In contrast, loss of LAP2α in Lmna(ΔK32/ΔK32) mice impaired the regulation of tissue progenitor cells as in lamin A/C wild-type animals. These data indicate that a LAP2α-independent assembly defect of ΔK32 lamin A/C is the predominant cause of the mouse pathology, whereas the LAP2α-linked functions of nucleoplasmic lamin A/C in the regulation of tissue progenitor cells are not affected in Lmna(ΔK32/ΔK32) mice.
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Affiliation(s)
- Ursula Pilat
- Max F. Perutz Laboratories, Department of Medical Biochemistry, Medical University of Vienna, Dr. Bohr-Gasse 9, A-1030 Vienna, Austria
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50
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Solovei I, Wang AS, Thanisch K, Schmidt CS, Krebs S, Zwerger M, Cohen TV, Devys D, Foisner R, Peichl L, Herrmann H, Blum H, Engelkamp D, Stewart CL, Leonhardt H, Joffe B. LBR and lamin A/C sequentially tether peripheral heterochromatin and inversely regulate differentiation. Cell 2013; 152:584-98. [PMID: 23374351 DOI: 10.1016/j.cell.2013.01.009] [Citation(s) in RCA: 600] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2012] [Revised: 09/14/2012] [Accepted: 01/07/2013] [Indexed: 01/26/2023]
Abstract
Eukaryotic cells have a layer of heterochromatin at the nuclear periphery. To investigate mechanisms regulating chromatin distribution, we analyzed heterochromatin organization in different tissues and species, including mice with mutations in the lamin B receptor (Lbr) and lamin A (Lmna) genes that encode nuclear envelope (NE) proteins. We identified LBR- and lamin-A/C-dependent mechanisms tethering heterochromatin to the NE. The two tethers are sequentially used during cellular differentiation and development: first the LBR- and then the lamin-A/C-dependent tether. The absence of both LBR and lamin A/C leads to loss of peripheral heterochromatin and an inverted architecture with heterochromatin localizing to the nuclear interior. Myoblast transcriptome analyses indicated that selective disruption of the LBR- or lamin-A-dependent heterochromatin tethers have opposite effects on muscle gene expression, either increasing or decreasing, respectively. These results show how changes in NE composition contribute to regulating heterochromatin positioning, gene expression, and cellular differentiation during development.
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Affiliation(s)
- Irina Solovei
- Department of Biology II, Center for Integrated Protein Science Munich (CIPSM), Ludwig-Maximilians University Munich, Grosshadernerstrasse 2, 82152 Planegg-Martinsried, Germany
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