1
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Hernández-Espinosa LC, Hernández-Muñoz R. Blood flow-bearing physical forces, endothelial glycocalyx, and liver enzyme mobilization: A hypothesis. J Gen Physiol 2024; 156:e202313462. [PMID: 38231124 PMCID: PMC10794122 DOI: 10.1085/jgp.202313462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 10/13/2023] [Accepted: 12/18/2023] [Indexed: 01/18/2024] Open
Abstract
Numerous elements involved in shear stress-induced signaling have been identified, recognizing their functions as mechanotransducing ion channels situated at cellular membranes. This form of mechanical signaling relies on transmembrane proteins and cytoplasmic proteins that restructure the cytoskeleton, contributing to mechanotransduction cascades. Notably, blood flow generates mechanical forces that significantly impact the structure and remodeling of blood vessels. The primary regulation of blood vessel responses occurs through hemodynamic forces acting on the endothelium. These mechanical events intricately govern endothelial biophysical, biochemical, and genetic responses. Endothelial cells, positioned on the intimal surface of blood vessels, have the capability to express components of the glycocalyx. This endothelial structure emerges as a pivotal factor in mechanotransduction and the regulation of vascular tone. The endothelial glycocalyx assumes diverse roles in both health and disease. Our findings propose a connection between the release of specific enzymes from the rat liver and variations in the hepatic blood flow/mass ratio. Importantly, this phenomenon is not correlated with liver necrosis. Consequently, this review serves as an exploration of the potential involvement of membrane proteins in a hypothetical mechanotransducing phenomenon capable of controlling the release of liver enzymes.
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Affiliation(s)
- Lorena Carmina Hernández-Espinosa
- Department of Cell Biology and Development, Institute of Cellular Physiology, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
| | - Rolando Hernández-Muñoz
- Department of Cell Biology and Development, Institute of Cellular Physiology, Universidad Nacional Autónoma de México (UNAM), Mexico City, Mexico
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2
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Yamamoto-Hino M, Ariura M, Tanaka M, Iwasaki YW, Kawaguchi K, Shimamoto Y, Goto S. PIGB maintains nuclear lamina organization in skeletal muscle of Drosophila. J Cell Biol 2024; 223:e202301062. [PMID: 38261271 PMCID: PMC10808031 DOI: 10.1083/jcb.202301062] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 10/09/2023] [Accepted: 11/17/2023] [Indexed: 01/24/2024] Open
Abstract
The nuclear lamina (NL) plays various roles and participates in nuclear integrity, chromatin organization, and transcriptional regulation. Lamin proteins, the main components of the NL, form a homogeneous meshwork structure under the nuclear envelope. Lamins are essential, but it is unknown whether their homogeneous distribution is important for nuclear function. Here, we found that PIGB, an enzyme involved in glycosylphosphatidylinositol (GPI) synthesis, is responsible for the homogeneous lamin meshwork in Drosophila. Loss of PIGB resulted in heterogeneous distributions of B-type lamin and lamin-binding proteins in larval muscles. These phenotypes were rescued by expression of PIGB lacking GPI synthesis activity. The PIGB mutant exhibited changes in lamina-associated domains that are large heterochromatic genomic regions in the NL, reduction of nuclear stiffness, and deformation of muscle fibers. These results suggest that PIGB maintains the homogeneous meshwork of the NL, which may be essential for chromatin distribution and nuclear mechanical properties.
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Affiliation(s)
- Miki Yamamoto-Hino
- Department of Life Science, College of Science, Rikkyo University, Tokyo, Japan
| | - Masaru Ariura
- Department of Molecular Biology, Keio University School of Medicine, Tokyo, Japan
| | - Masahito Tanaka
- Department of Chromosome Science, National Institute of Genetics, Mishima, Japan
| | - Yuka W. Iwasaki
- Department of Molecular Biology, Keio University School of Medicine, Tokyo, Japan
- Laboratory for Functional Non-Coding Genomics, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
- Japan Science and Technology Agency (JST), Precursory Research for Embryonic Science and Technology (PRESTO), Saitama, Japan
| | - Kohei Kawaguchi
- Department of Life Science, College of Science, Rikkyo University, Tokyo, Japan
| | - Yuta Shimamoto
- Department of Chromosome Science, National Institute of Genetics, Mishima, Japan
| | - Satoshi Goto
- Department of Life Science, College of Science, Rikkyo University, Tokyo, Japan
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3
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Odell J, Gräf R, Lammerding J. Heterologous expression of Dictyostelium discoideum NE81 in mouse embryo fibroblasts reveals conserved mechanoprotective roles of lamins. Mol Biol Cell 2024; 35:ar7. [PMID: 37910203 PMCID: PMC10881167 DOI: 10.1091/mbc.e23-05-0193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 10/24/2023] [Accepted: 10/24/2023] [Indexed: 11/03/2023] Open
Abstract
Lamins are nuclear intermediate filament proteins that are ubiquitously found in metazoan cells, where they contribute to nuclear morphology, stability, and gene expression. Lamin-like sequences have recently been identified in distantly related eukaryotes, but it remains unclear whether these proteins share conserved functions with the lamins found in metazoans. Here, we investigate conserved features between metazoan and amoebozoan lamins using a genetic complementation system to express the Dictyostelium discoideum lamin-like protein NE81 in mammalian cells lacking either specific lamins or all endogenous lamins. We report that NE81 localizes to the nucleus in cells lacking Lamin A/C, and that NE81 expression improves nuclear circularity, reduces nuclear deformability, and prevents nuclear envelope rupture in these cells. However, NE81 did not completely rescue loss of Lamin A/C, and was unable to restore normal distribution of metazoan lamin interactors, such as emerin and nuclear pore complexes, which are frequently displaced in Lamin A/C deficient cells. Collectively, our results indicate that the ability of lamins to modulate the morphology and mechanical properties of nuclei may have been a feature present in the common ancestor of Dictyostelium and animals, whereas other, more specialized interactions may have evolved more recently in metazoan lineages.
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Affiliation(s)
- Jacob Odell
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
- Graduate Field of Biochemistry, Molecular and Cell Biology, Cornell University, Ithaca, NY 14853
| | - Ralph Gräf
- Department of Cell Biology, University of Potsdam, 14476 Potsdam-Golm, Germany
| | - Jan Lammerding
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853
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4
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West G, Sedighi S, Agnetti G, Taimen P. Intermediate filaments in the heart: The dynamic duo of desmin and lamins orchestrates mechanical force transmission. Curr Opin Cell Biol 2023; 85:102280. [PMID: 37972529 DOI: 10.1016/j.ceb.2023.102280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 10/05/2023] [Accepted: 10/25/2023] [Indexed: 11/19/2023]
Abstract
The intermediate filament (IF) cytoskeleton supports cellular structural integrity, particularly in response to mechanical stress. The most abundant IF proteins in mature cardiomyocytes are desmin and lamins. The desmin network tethers the contractile apparatus and organelles to the nuclear envelope and the sarcolemma, while lamins, as components of the nuclear lamina, provide structural stability to the nucleus and the genome. Mutations in desmin or A-type lamins typically result in cardiomyopathies and recent studies emphasized the synergistic roles of desmin and lamins in the maintenance of nuclear integrity in cardiac myocytes. Here we explore the emerging roles of the interdependent relationship between desmin and lamins in providing resilience to nuclear structure while transducing extracellular mechanical cues into the nucleus.
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Affiliation(s)
- Gun West
- Institute of Biomedicine and FICAN West Cancer Centre, University of Turku, 20520, Turku, Finland
| | - Sogol Sedighi
- Johns Hopkins University School of Medicine, 21205, Baltimore, MD, USA
| | - Giulio Agnetti
- Johns Hopkins University School of Medicine, 21205, Baltimore, MD, USA; DIBINEM - University of Bologna, 40123, Bologna, Italy.
| | - Pekka Taimen
- Institute of Biomedicine and FICAN West Cancer Centre, University of Turku, 20520, Turku, Finland; Department of Pathology, Turku University Hospital, 20520, Turku, Finland.
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5
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Odell J, Gräf R, Lammerding J. Heterologous expression of Dictyostelium discoideum NE81 in mouse embryo fibroblasts reveals conserved mechanoprotective roles of lamins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.31.543154. [PMID: 37398420 PMCID: PMC10312578 DOI: 10.1101/2023.05.31.543154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Lamins are nuclear intermediate filament proteins that are ubiquitously found in metazoan cells, where they contribute to nuclear morphology, stability, and gene expression. Lamin-like sequences have recently been identified in distantly related eukaryotes, but it remains unclear if these proteins share conserved functions with the lamins found in metazoans. Here, we investigate conserved features between metazoan and amoebozoan lamins using a genetic complementation system to express the Dictyostelium discoideum lamin-like protein NE81 in mammalian cells lacking either specific lamins or all endogenous lamins. We report that NE81 localizes to the nucleus in cells lacking Lamin A/C, and that NE81 expression improves nuclear circularity, reduces nuclear deformability, and prevents nuclear envelope rupture in these cells. However, NE81 did not completely rescue loss of Lamin A/C, and was unable to restore normal distribution of metazoan lamin interactors, such as emerin and nuclear pore complexes, which are frequently displaced in Lamin A/C deficient cells. Collectively, our results indicate that the ability of lamins to modulate the morphology and mechanical properties of nuclei may have been a feature present in the common ancestor of Dictyostelium and animals, whereas other, more specialized interactions may have evolved more recently in metazoan lineages.
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6
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Wallace M, Zahr H, Perati S, Morsink CD, Johnson LE, Gacita AM, Lai S, Wallrath LL, Benjamin IJ, McNally EM, Kirby TJ, Lammerding J. Nuclear damage in LMNA mutant iPSC-derived cardiomyocytes is associated with impaired lamin localization to the nuclear envelope. Mol Biol Cell 2023; 34:mbcE21100527. [PMID: 37585285 PMCID: PMC10846625 DOI: 10.1091/mbc.e21-10-0527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 07/31/2023] [Accepted: 08/10/2023] [Indexed: 08/18/2023] Open
Abstract
The LMNA gene encodes the nuclear envelope proteins Lamins A and C, which comprise a major part of the nuclear lamina, provide mechanical support to the nucleus, and participate in diverse intracellular signaling. LMNA mutations give rise to a collection of diseases called laminopathies, including dilated cardiomyopathy (LMNA-DCM) and muscular dystrophies. Although nuclear deformities are a hallmark of LMNA-DCM, the role of nuclear abnormalities in the pathogenesis of LMNA-DCM remains incompletely understood. Using induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs) from LMNA mutant patients and healthy controls, we show that LMNA mutant iPSC-CM nuclei have altered shape or increased size compared to healthy control iPSC-CM nuclei. The LMNA mutation exhibiting the most severe nuclear deformities, R249Q, additionally caused reduced nuclear stiffness and increased nuclear fragility. Importantly, for all cell lines, the degree of nuclear abnormalities corresponded to the degree of Lamin A/C and Lamin B1 mislocalization from the nuclear envelope. The mislocalization was likely due to altered assembly of Lamin A/C. Collectively, these results point to the importance of correct lamin assembly at the nuclear envelope in providing mechanical stability to the nucleus and suggest that defects in nuclear lamina organization may contribute to the nuclear and cellular dysfunction in LMNA-DCM.
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Affiliation(s)
- Melanie Wallace
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853
- Weill Institute for Cell and Molecular Biology, Ithaca, NY 14853
| | - Hind Zahr
- Weill Institute for Cell and Molecular Biology, Ithaca, NY 14853
| | - Shriya Perati
- Weill Institute for Cell and Molecular Biology, Ithaca, NY 14853
| | - Chloé D. Morsink
- Department of Physiology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, VU Medical Center, 1081 HZ Amsterdam, The Netherlands
| | | | - Anthony M. Gacita
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern Medicine, Chicago, IL 60611
| | - Shuping Lai
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Lori L. Wallrath
- Department of Biochemistry and Molecular Biology, University of Iowa, Iowa City, IA 52242
| | - Ivor J. Benjamin
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI 53226
| | - Elizabeth M. McNally
- Center for Genetic Medicine, Feinberg School of Medicine, Northwestern Medicine, Chicago, IL 60611
| | - Tyler J. Kirby
- Weill Institute for Cell and Molecular Biology, Ithaca, NY 14853
- Department of Physiology, Amsterdam University Medical Centers, Amsterdam Cardiovascular Sciences, VU Medical Center, 1081 HZ Amsterdam, The Netherlands
| | - Jan Lammerding
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853
- Weill Institute for Cell and Molecular Biology, Ithaca, NY 14853
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7
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Benarroch L, Madsen-Østerbye J, Abdelhalim M, Mamchaoui K, Ohana J, Bigot A, Mouly V, Bonne G, Bertrand AT, Collas P. Cellular and Genomic Features of Muscle Differentiation from Isogenic Fibroblasts and Myoblasts. Cells 2023; 12:1995. [PMID: 37566074 PMCID: PMC10417614 DOI: 10.3390/cells12151995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2023] [Revised: 07/27/2023] [Accepted: 07/31/2023] [Indexed: 08/12/2023] Open
Abstract
The ability to recapitulate muscle differentiation in vitro enables the exploration of mechanisms underlying myogenesis and muscle diseases. However, obtaining myoblasts from patients with neuromuscular diseases or from healthy subjects poses ethical and procedural challenges that limit such investigations. An alternative consists in converting skin fibroblasts into myogenic cells by forcing the expression of the myogenic regulator MYOD. Here, we directly compared cellular phenotype, transcriptome, and nuclear lamina-associated domains (LADs) in myo-converted human fibroblasts and myotubes differentiated from myoblasts. We used isogenic cells from a 16-year-old donor, ruling out, for the first time to our knowledge, genetic factors as a source of variations between the two myogenic models. We show that myo-conversion of fibroblasts upregulates genes controlling myogenic pathways leading to multinucleated cells expressing muscle cell markers. However, myotubes are more advanced in myogenesis than myo-converted fibroblasts at the phenotypic and transcriptomic levels. While most LADs are shared between the two cell types, each also displays unique domains of lamin A/C interactions. Furthermore, myotube-specific LADs are more gene-rich and less heterochromatic than shared LADs or LADs unique to myo-converted fibroblasts, and they uniquely sequester developmental genes. Thus, myo-converted fibroblasts and myotubes retain cell type-specific features of radial and functional genome organization. Our results favor a view of myo-converted fibroblasts as a practical model to investigate the phenotypic and genomic properties of muscle cell differentiation in normal and pathological contexts, but also highlight current limitations in using fibroblasts as a source of myogenic cells.
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Affiliation(s)
- Louise Benarroch
- Sorbonne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, 75013 Paris, France; (L.B.); (K.M.); (J.O.); (A.B.); (V.M.); (G.B.)
| | - Julia Madsen-Østerbye
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, 0372 Oslo, Norway; (J.M.-Ø.); (M.A.)
- Department of Immunology and Transfusion Medicine, Oslo University Hospital, 0372 Oslo, Norway
| | - Mohamed Abdelhalim
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, 0372 Oslo, Norway; (J.M.-Ø.); (M.A.)
| | - Kamel Mamchaoui
- Sorbonne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, 75013 Paris, France; (L.B.); (K.M.); (J.O.); (A.B.); (V.M.); (G.B.)
| | - Jessica Ohana
- Sorbonne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, 75013 Paris, France; (L.B.); (K.M.); (J.O.); (A.B.); (V.M.); (G.B.)
| | - Anne Bigot
- Sorbonne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, 75013 Paris, France; (L.B.); (K.M.); (J.O.); (A.B.); (V.M.); (G.B.)
| | - Vincent Mouly
- Sorbonne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, 75013 Paris, France; (L.B.); (K.M.); (J.O.); (A.B.); (V.M.); (G.B.)
| | - Gisèle Bonne
- Sorbonne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, 75013 Paris, France; (L.B.); (K.M.); (J.O.); (A.B.); (V.M.); (G.B.)
| | - Anne T. Bertrand
- Sorbonne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, 75013 Paris, France; (L.B.); (K.M.); (J.O.); (A.B.); (V.M.); (G.B.)
| | - Philippe Collas
- Department of Molecular Medicine, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, 0372 Oslo, Norway; (J.M.-Ø.); (M.A.)
- Department of Immunology and Transfusion Medicine, Oslo University Hospital, 0372 Oslo, Norway
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8
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Gregory EF, Kalra S, Brock T, Bonne G, Luxton GWG, Hopkins C, Starr DA. Caenorhabditis elegans models for striated muscle disorders caused by missense variants of human LMNA. PLoS Genet 2023; 19:e1010895. [PMID: 37624850 PMCID: PMC10484454 DOI: 10.1371/journal.pgen.1010895] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 09/07/2023] [Accepted: 08/01/2023] [Indexed: 08/27/2023] Open
Abstract
Striated muscle laminopathies caused by missense mutations in the nuclear lamin gene LMNA are characterized by cardiac dysfunction and often skeletal muscle defects. Attempts to predict which LMNA variants are pathogenic and to understand their physiological effects lag behind variant discovery. We created Caenorhabditis elegans models for striated muscle laminopathies by introducing pathogenic human LMNA variants and variants of unknown significance at conserved residues within the lmn-1 gene. Severe missense variants reduced fertility and/or motility in C. elegans. Nuclear morphology defects were evident in the hypodermal nuclei of many lamin variant strains, indicating a loss of nuclear envelope integrity. Phenotypic severity varied within the two classes of missense mutations involved in striated muscle disease, but overall, variants associated with both skeletal and cardiac muscle defects in humans lead to more severe phenotypes in our model than variants predicted to disrupt cardiac function alone. We also identified a separation of function allele, lmn-1(R204W), that exhibited normal viability and swimming behavior but had a severe nuclear migration defect. Thus, we established C. elegans avatars for striated muscle laminopathies and identified LMNA variants that offer insight into lamin mechanisms during normal development.
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Affiliation(s)
- Ellen F. Gregory
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| | - Shilpi Kalra
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| | - Trisha Brock
- InVivo Biosystems, Eugene, Oregon, United States of America
| | - Gisèle Bonne
- Sorbonne Université, Inserm, Institut de Myologie, Centre de Recherche en Myologie, Paris, France
| | - G. W. Gant Luxton
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
| | | | - Daniel A. Starr
- Department of Molecular and Cellular Biology, University of California, Davis, California, United States of America
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9
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Pande S, Ghosh DK. Nuclear proteostasis imbalance in laminopathy-associated premature aging diseases. FASEB J 2023; 37:e23116. [PMID: 37498235 DOI: 10.1096/fj.202300878r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Revised: 06/15/2023] [Accepted: 07/13/2023] [Indexed: 07/28/2023]
Abstract
Laminopathies are a group of rare genetic disorders with heterogeneous clinical phenotypes such as premature aging, cardiomyopathy, lipodystrophy, muscular dystrophy, microcephaly, epilepsy, and so on. The cellular phenomena associated with laminopathy invariably show disruption of nucleoskeleton of lamina due to deregulated expression, localization, function, and interaction of mutant lamin proteins. Impaired spatial and temporal tethering of lamin proteins to the lamina or nucleoplasmic aggregation of lamins are the primary molecular events that can trigger nuclear proteotoxicity by modulating differential protein-protein interactions, sequestering quality control proteins, and initiating a cascade of abnormal post-translational modifications. Clearly, laminopathic cells exhibit moderate to high nuclear proteotoxicity, raising the question of whether an imbalance in nuclear proteostasis is involved in laminopathic diseases, particularly in diseases of early aging such as HGPS and laminopathy-associated premature aging. Here, we review nuclear proteostasis and its deregulation in the context of lamin proteins and laminopathies.
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Affiliation(s)
- Shruti Pande
- Department of Medical Genetics, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
| | - Debasish Kumar Ghosh
- Enteric Disease Division, Department of Microbiology, Kasturba Medical College, Manipal, Manipal Academy of Higher Education, Manipal, India
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10
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Oses C, De Rossi MC, Bruno L, Verneri P, Diaz MC, Benítez B, Guberman A, Levi V. From the membrane to the nucleus: mechanical signals and transcription regulation. Biophys Rev 2023; 15:671-683. [PMID: 37681098 PMCID: PMC10480138 DOI: 10.1007/s12551-023-01103-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2023] [Accepted: 07/20/2023] [Indexed: 09/09/2023] Open
Abstract
Mechanical forces drive and modulate a wide variety of processes in eukaryotic cells including those occurring in the nucleus. Relevantly, forces are fundamental during development since they guide lineage specifications of embryonic stem cells. A sophisticated macromolecular machinery transduces mechanical stimuli received at the cell surface into a biochemical output; a key component in this mechanical communication is the cytoskeleton, a complex network of biofilaments in constant remodeling that links the cell membrane to the nuclear envelope. Recent evidence highlights that forces transmitted through the cytoskeleton directly affect the organization of chromatin and the accessibility of transcription-related molecules to their targets in the DNA. Consequently, mechanical forces can directly modulate transcription and change gene expression programs. Here, we will revise the biophysical toolbox involved in the mechanical communication with the cell nucleus and discuss how mechanical forces impact on the organization of this organelle and more specifically, on transcription. We will also discuss how live-cell fluorescence imaging is producing exquisite information to understand the mechanical response of cells and to quantify the landscape of interactions of transcription factors with chromatin in embryonic stem cells. These studies are building new biophysical insights that could be fundamental to achieve the goal of manipulating forces to guide cell differentiation in culture systems.
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Affiliation(s)
- Camila Oses
- Instituto de Química Biológica de La Facultad de Ciencias Exactas Y Naturales (IQUIBICEN), Facultad de Ciencias Exactas Y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina
| | - María Cecilia De Rossi
- Instituto de Química Biológica de La Facultad de Ciencias Exactas Y Naturales (IQUIBICEN), Facultad de Ciencias Exactas Y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina
| | - Luciana Bruno
- Facultad de Ciencias Exactas Y Naturales, Instituto de Cálculo (IC), CONICET-Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina
| | - Paula Verneri
- Instituto de Química Biológica de La Facultad de Ciencias Exactas Y Naturales (IQUIBICEN), Facultad de Ciencias Exactas Y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina
| | - María Candelaria Diaz
- Instituto de Química Biológica de La Facultad de Ciencias Exactas Y Naturales (IQUIBICEN), Facultad de Ciencias Exactas Y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina
| | - Belén Benítez
- Instituto de Fisiología, Biología Molecular Y Neurociencias (IFIBYNE), Facultad de Ciencias Exactas Y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina
| | - Alejandra Guberman
- Instituto de Química Biológica de La Facultad de Ciencias Exactas Y Naturales (IQUIBICEN), Facultad de Ciencias Exactas Y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina
- Facultad de Ciencias Exactas Y Naturales, Departamento de Fisiología, Universidad de Buenos Aires, Biología Molecular Y Celular, C1428EGA Buenos Aires, Argentina
| | - Valeria Levi
- Instituto de Química Biológica de La Facultad de Ciencias Exactas Y Naturales (IQUIBICEN), Facultad de Ciencias Exactas Y Naturales, CONICET-Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina
- Facultad de Ciencias Exactas Y Naturales, Departamento de Química Biológica, Universidad de Buenos Aires, C1428EGA Buenos Aires, Argentina
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11
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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: 0] [Impact Index Per Article: 0] [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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12
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de Las Heras JI, Todorow V, Krečinić-Balić L, Hintze S, Czapiewski R, Webb S, Schoser B, Meinke P, Schirmer EC. Metabolic, fibrotic and splicing pathways are all altered in Emery-Dreifuss muscular dystrophy spectrum patients to differing degrees. Hum Mol Genet 2023; 32:1010-1031. [PMID: 36282542 PMCID: PMC9991002 DOI: 10.1093/hmg/ddac264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Revised: 09/16/2022] [Accepted: 10/20/2022] [Indexed: 11/14/2022] Open
Abstract
Emery-Dreifuss muscular dystrophy (EDMD) is a genetically and clinically variable disorder. Previous attempts to use gene expression changes to find its pathomechanism were unavailing, so we engaged a functional pathway analysis. RNA-Seq was performed on cells from 10 patients diagnosed with an EDMD spectrum disease with different mutations in seven genes. Upon comparing to controls, the pathway analysis revealed that multiple genes involved in fibrosis, metabolism, myogenic signaling and splicing were affected in all patients. Splice variant analysis revealed alterations of muscle-specific variants for several important muscle genes. Deeper analysis of metabolic pathways revealed a reduction in glycolytic and oxidative metabolism and reduced numbers of mitochondria across a larger set of 14 EDMD spectrum patients and 7 controls. Intriguingly, the gene expression signatures segregated the patients into three subgroups whose distinctions could potentially relate to differences in clinical presentation. Finally, differential expression analysis of miRNAs changing in the patients similarly highlighted fibrosis, metabolism and myogenic signaling pathways. This pathway approach revealed a transcriptome profile that can both be used as a template for establishing a biomarker panel for EDMD and direct further investigation into its pathomechanism. Furthermore, the segregation of specific gene changes into distinct groups that appear to correlate with clinical presentation may template development of prognostic biomarkers, though this will first require their testing in a wider set of patients with more clinical information.
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Affiliation(s)
| | - Vanessa Todorow
- Friedrich-Baur-Institute, Department of Neurology, LMU Clinic, Ludwig-Maximillians-University, Munich, Germany
| | - Lejla Krečinić-Balić
- Friedrich-Baur-Institute, Department of Neurology, LMU Clinic, Ludwig-Maximillians-University, Munich, Germany
| | - Stefan Hintze
- Friedrich-Baur-Institute, Department of Neurology, LMU Clinic, Ludwig-Maximillians-University, Munich, Germany
| | - Rafal Czapiewski
- Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Shaun Webb
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Benedikt Schoser
- Friedrich-Baur-Institute, Department of Neurology, LMU Clinic, Ludwig-Maximillians-University, Munich, Germany
| | - Peter Meinke
- Friedrich-Baur-Institute, Department of Neurology, LMU Clinic, Ludwig-Maximillians-University, Munich, Germany
| | - Eric C Schirmer
- Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
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13
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Kalukula Y, Stephens AD, Lammerding J, Gabriele S. Mechanics and functional consequences of nuclear deformations. Nat Rev Mol Cell Biol 2022; 23:583-602. [PMID: 35513718 PMCID: PMC9902167 DOI: 10.1038/s41580-022-00480-z] [Citation(s) in RCA: 93] [Impact Index Per Article: 46.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/29/2022] [Indexed: 02/08/2023]
Abstract
As the home of cellular genetic information, the nucleus has a critical role in determining cell fate and function in response to various signals and stimuli. In addition to biochemical inputs, the nucleus is constantly exposed to intrinsic and extrinsic mechanical forces that trigger dynamic changes in nuclear structure and morphology. Emerging data suggest that the physical deformation of the nucleus modulates many cellular and nuclear functions. These functions have long been considered to be downstream of cytoplasmic signalling pathways and dictated by gene expression. In this Review, we discuss an emerging perspective on the mechanoregulation of the nucleus that considers the physical connections from chromatin to nuclear lamina and cytoskeletal filaments as a single mechanical unit. We describe key mechanisms of nuclear deformations in time and space and provide a critical review of the structural and functional adaptive responses of the nucleus to deformations. We then consider the contribution of nuclear deformations to the regulation of important cellular functions, including muscle contraction, cell migration and human disease pathogenesis. Collectively, these emerging insights shed new light on the dynamics of nuclear deformations and their roles in cellular mechanobiology.
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Affiliation(s)
- Yohalie Kalukula
- University of Mons, Soft Matter and Biomaterials group, Interfaces and Complex Fluids Laboratory, Research Institute for Biosciences, CIRMAP, Place du Parc, 20 B-7000 Mons, Belgium
| | - Andrew D. Stephens
- Biology Department, University of Massachusetts Amherst, Amherst, MA, USA
| | - Jan Lammerding
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853, USA,Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY 14853, USA
| | - Sylvain Gabriele
- University of Mons, Soft Matter and Biomaterials group, Interfaces and Complex Fluids Laboratory, Research Institute for Biosciences, CIRMAP, Place du Parc, 20 B-7000 Mons, Belgium
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14
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Bell ES, Shah P, Zuela-Sopilniak N, Kim D, Varlet AA, Morival JL, McGregor AL, Isermann P, Davidson PM, Elacqua JJ, Lakins JN, Vahdat L, Weaver VM, Smolka MB, Span PN, Lammerding J. Low lamin A levels enhance confined cell migration and metastatic capacity in breast cancer. Oncogene 2022; 41:4211-4230. [PMID: 35896617 PMCID: PMC9925375 DOI: 10.1038/s41388-022-02420-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 07/12/2022] [Accepted: 07/14/2022] [Indexed: 02/07/2023]
Abstract
Aberrations in nuclear size and shape are commonly used to identify cancerous tissue. However, it remains unclear whether the disturbed nuclear structure directly contributes to the cancer pathology or is merely a consequence of other events occurring during tumorigenesis. Here, we show that highly invasive and proliferative breast cancer cells frequently exhibit Akt-driven lower expression of the nuclear envelope proteins lamin A/C, leading to increased nuclear deformability that permits enhanced cell migration through confined environments that mimic interstitial spaces encountered during metastasis. Importantly, increasing lamin A/C expression in highly invasive breast cancer cells reflected gene expression changes characteristic of human breast tumors with higher LMNA expression, and specifically affected pathways related to cell-ECM interactions, cell metabolism, and PI3K/Akt signaling. Further supporting an important role of lamins in breast cancer metastasis, analysis of lamin levels in human breast tumors revealed a significant association between lower lamin A levels, Akt signaling, and decreased disease-free survival. These findings suggest that downregulation of lamin A/C in breast cancer cells may influence both cellular physical properties and biochemical signaling to promote metastatic progression.
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Affiliation(s)
- Emily S. Bell
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY,Current address: Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA
| | - Pragya Shah
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | | | - Dongsung Kim
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Alice-Anais Varlet
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Julien L.P. Morival
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Alexandra L. McGregor
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY,Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY
| | - Philipp Isermann
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | | | - Joshua J. Elacqua
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Jonathan N. Lakins
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA
| | - Linda Vahdat
- Department of Medicine, Weill Cornell Medicine, New York, NY
| | - Valerie M. Weaver
- Center for Bioengineering and Tissue Regeneration, Department of Surgery, University of California, San Francisco, San Francisco, CA,Helen Diller Cancer Center, Department of Bioengineering and Therapeutic Sciences, and Department of Radiation Oncology, University of California, San Francisco, San Francisco, CA
| | - Marcus B. Smolka
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY
| | - Paul N. Span
- Department of Radiation Oncology, Radiotherapy & OncoImmunology laboratory, Radboud University Nijmegen Medical Center, Nijmegen, the Netherlands
| | - Jan Lammerding
- Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA. .,Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA.
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15
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Shaw NM, Rios-Monterrosa JL, Fedorchak GR, Ketterer MR, Coombs GS, Lammerding J, Wallrath LL. Effects of mutant lamins on nucleo-cytoskeletal coupling in Drosophila models of LMNA muscular dystrophy. Front Cell Dev Biol 2022; 10:934586. [PMID: 36120560 PMCID: PMC9471154 DOI: 10.3389/fcell.2022.934586] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
The nuclei of multinucleated skeletal muscles experience substantial external force during development and muscle contraction. Protection from such forces is partly provided by lamins, intermediate filaments that form a scaffold lining the inner nuclear membrane. Lamins play a myriad of roles, including maintenance of nuclear shape and stability, mediation of nuclear mechanoresponses, and nucleo-cytoskeletal coupling. Herein, we investigate how disease-causing mutant lamins alter myonuclear properties in response to mechanical force. This was accomplished via a novel application of a micropipette harpooning assay applied to larval body wall muscles of Drosophila models of lamin-associated muscular dystrophy. The assay enables the measurement of both nuclear deformability and intracellular force transmission between the cytoskeleton and nuclear interior in intact muscle fibers. Our studies revealed that specific mutant lamins increase nuclear deformability while other mutant lamins cause nucleo-cytoskeletal coupling defects, which were associated with loss of microtubular nuclear caging. We found that microtubule caging of the nucleus depended on Msp300, a KASH domain protein that is a component of the linker of nucleoskeleton and cytoskeleton (LINC) complex. Taken together, these findings identified residues in lamins required for connecting the nucleus to the cytoskeleton and suggest that not all muscle disease-causing mutant lamins produce similar defects in subcellular mechanics.
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Affiliation(s)
- Nicholas M. Shaw
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Jose L. Rios-Monterrosa
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Gregory R. Fedorchak
- The Nancy E. and Peter C. Meinig School of Biomedical Engineering, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, United States
| | - Margaret R. Ketterer
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
| | - Gary S. Coombs
- Biology Department, Waldorf University, Forest City, IA, United States
| | - Jan Lammerding
- The Nancy E. and Peter C. Meinig School of Biomedical Engineering, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, United States
| | - Lori L. Wallrath
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, United States
- *Correspondence: Lori L. Wallrath,
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16
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Chen J, Ma Y, Li H, Lin Z, Yang Z, Zhang Q, Wang F, Lin Y, Ye Z, Lin Y. Rare and potential pathogenic mutations of LMNA and LAMA4 associated with familial arrhythmogenic right ventricular cardiomyopathy/dysplasia with right ventricular heart failure, cerebral thromboembolism and hereditary electrocardiogram abnormality. Orphanet J Rare Dis 2022; 17:183. [PMID: 35526016 PMCID: PMC9077868 DOI: 10.1186/s13023-022-02348-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Accepted: 04/26/2022] [Indexed: 12/20/2022] Open
Abstract
Background Arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is associated with ventricular arrhythmia, heart failure (HF), and sudden death. Thromboembolism is also an important and serious complication of ARVC/D. However, the etiology of ARVC/D and thromboembolism and their association with genetic mutations are unclear. Methods Genomic DNA samples of peripheral blood were conducted for whole-exome sequencing (WES) and Sanger sequencing in the ARVC/D family. Then, we performed bioinformatics analysis for genes susceptible to cardiomyopathies and arrhythmias. Further, we analyzed how the potential pathogenic mutations were affecting the hydrophobicity and phosphorylation of amino acids and their joint pathogenicity by ProtScale, NetPhos and ORVAL algorisms. Results We discovered a Chinese Han family of ARVC/D with right ventricular HF (RVHF), cerebral thromboembolism, arrhythmias (atrial fibrillation, atrial standstill, multifocal ventricular premature, complete right bundle block and third-degree atrioventricular block) and sudden death. Based on the WES data, the variants of LMNA p.A242V, LAMA4 p.A225P and RYR2 p.T858M are highly conserved and predicated as “deleterious” by SIFT and MetaSVM algorithms. Their CADD predicting scores are 33, 27.4 and 25.8, respectively. These variants increase the hydrophobicity of their corresponding amino acid residues and their nearby sequences by 0.378, 0.266 and 0.289, respectively. The LAMA4 and RYR2 variants lead to changes in protein phosphorylation at or near their corresponding amino acid sites. There were high risks of joint pathogenicity for cardiomyopathy among these three variants. Cosegregation analysis indicated that LMNA p.A242V might be an important risk factor for ARVC/D, electrocardiogram abnormality and cerebral thromboembolism, while LAMA4 p.A225P may be a pathogenic etiology of ARVC/D and hereditary electrocardiogram abnormality. Conclusions The LMNA p.A242V may participate in the pathogenesis of familial ARVC/D with RVHF and cerebral thromboembolism, while LAMA4 p.A225P may be associated with ARVC/D and hereditary electrocardiogram abnormality.
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Affiliation(s)
- Jia Chen
- The Second Department of Cardiology, Department of Obstetrics and Gynecology, The Second People's Hospital of Guangdong Province, Guangzhou, 510310, China
| | - Yuting Ma
- The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan, 523710, Guangdong Province, China.,College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hong Li
- The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan, 523710, Guangdong Province, China.,School of Public Health, Jinzhou Medical University, Jinzhou, 121001, China
| | - Zhuo Lin
- The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan, 523710, Guangdong Province, China
| | - Zhe Yang
- The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan, 523710, Guangdong Province, China
| | - Qin Zhang
- The Center of Cardiovascular Diseases, The Department of Cardiology, The Fifth Affiliated Hospital, Sun Yat-Sen University, Zhuhai, 519000, China
| | - Feng Wang
- Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangdong Geriatrics Institute, Guangdong Cardiovascular Institute, Guangzhou, 510080, China
| | - Yanping Lin
- The Second Department of Cardiology, Department of Obstetrics and Gynecology, The Second People's Hospital of Guangdong Province, Guangzhou, 510310, China
| | - Zebing Ye
- The Second Department of Cardiology, Department of Obstetrics and Gynecology, The Second People's Hospital of Guangdong Province, Guangzhou, 510310, China
| | - Yubi Lin
- The First Dongguan Affiliated Hospital, Guangdong Medical University, Dongguan, 523710, Guangdong Province, China.
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17
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Mierke CT. Viscoelasticity, Like Forces, Plays a Role in Mechanotransduction. Front Cell Dev Biol 2022; 10:789841. [PMID: 35223831 PMCID: PMC8864183 DOI: 10.3389/fcell.2022.789841] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Accepted: 01/11/2022] [Indexed: 12/13/2022] Open
Abstract
Viscoelasticity and its alteration in time and space has turned out to act as a key element in fundamental biological processes in living systems, such as morphogenesis and motility. Based on experimental and theoretical findings it can be proposed that viscoelasticity of cells, spheroids and tissues seems to be a collective characteristic that demands macromolecular, intracellular component and intercellular interactions. A major challenge is to couple the alterations in the macroscopic structural or material characteristics of cells, spheroids and tissues, such as cell and tissue phase transitions, to the microscopic interferences of their elements. Therefore, the biophysical technologies need to be improved, advanced and connected to classical biological assays. In this review, the viscoelastic nature of cytoskeletal, extracellular and cellular networks is presented and discussed. Viscoelasticity is conceptualized as a major contributor to cell migration and invasion and it is discussed whether it can serve as a biomarker for the cells’ migratory capacity in several biological contexts. It can be hypothesized that the statistical mechanics of intra- and extracellular networks may be applied in the future as a powerful tool to explore quantitatively the biomechanical foundation of viscoelasticity over a broad range of time and length scales. Finally, the importance of the cellular viscoelasticity is illustrated in identifying and characterizing multiple disorders, such as cancer, tissue injuries, acute or chronic inflammations or fibrotic diseases.
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18
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Belyaeva V, Wachner S, Gyoergy A, Emtenani S, Gridchyn I, Akhmanova M, Linder M, Roblek M, Sibilia M, Siekhaus D. Fos regulates macrophage infiltration against surrounding tissue resistance by a cortical actin-based mechanism in Drosophila. PLoS Biol 2022; 20:e3001494. [PMID: 34990456 PMCID: PMC8735623 DOI: 10.1371/journal.pbio.3001494] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Accepted: 11/25/2021] [Indexed: 12/20/2022] Open
Abstract
The infiltration of immune cells into tissues underlies the establishment of tissue-resident macrophages and responses to infections and tumors. Yet the mechanisms immune cells utilize to negotiate tissue barriers in living organisms are not well understood, and a role for cortical actin has not been examined. Here, we find that the tissue invasion of Drosophila macrophages, also known as plasmatocytes or hemocytes, utilizes enhanced cortical F-actin levels stimulated by the Drosophila member of the fos proto oncogene transcription factor family (Dfos, Kayak). RNA sequencing analysis and live imaging show that Dfos enhances F-actin levels around the entire macrophage surface by increasing mRNA levels of the membrane spanning molecular scaffold tetraspanin TM4SF, and the actin cross-linking filamin Cheerio, which are themselves required for invasion. Both the filamin and the tetraspanin enhance the cortical activity of Rho1 and the formin Diaphanous and thus the assembly of cortical actin, which is a critical function since expressing a dominant active form of Diaphanous can rescue the Dfos macrophage invasion defect. In vivo imaging shows that Dfos enhances the efficiency of the initial phases of macrophage tissue entry. Genetic evidence argues that this Dfos-induced program in macrophages counteracts the constraint produced by the tension of surrounding tissues and buffers the properties of the macrophage nucleus from affecting tissue entry. We thus identify strengthening the cortical actin cytoskeleton through Dfos as a key process allowing efficient forward movement of an immune cell into surrounding tissues. The infiltration of immune cells into tissue underlies the establishment of tissue-resident macrophages, and responses to infections and tumors, but how do they overcome tissue barriers? This study shows that macrophages upregulate the proto-oncogene Fos, increasing the density and crosslinking of cortical actin, thereby counteracting the tension of surrounding tissues and protecting the macrophage nucleus.
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Affiliation(s)
- Vera Belyaeva
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Stephanie Wachner
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Attila Gyoergy
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Shamsi Emtenani
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Igor Gridchyn
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Maria Akhmanova
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Markus Linder
- Institute of Cancer Research, Department of Medicine 1, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Marko Roblek
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Maria Sibilia
- Institute of Cancer Research, Department of Medicine 1, Comprehensive Cancer Center, Medical University of Vienna, Vienna, Austria
| | - Daria Siekhaus
- Institute of Science and Technology Austria, Klosterneuburg, Austria
- * E-mail:
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19
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Most myopathic lamin variants aggregate: a functional genomics approach for assessing variants of uncertain significance. NPJ Genom Med 2021; 6:103. [PMID: 34862408 PMCID: PMC8642518 DOI: 10.1038/s41525-021-00265-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2020] [Accepted: 10/21/2021] [Indexed: 02/01/2023] Open
Abstract
Hundreds of LMNA variants have been associated with several distinct disease phenotypes. However, genotype-phenotype relationships remain largely undefined and the impact for most variants remains unknown. We performed a functional analysis for 178 variants across five structural domains using two different overexpression models. We found that lamin A aggregation is a major determinant for skeletal and cardiac laminopathies. An in vitro solubility assay shows that aggregation-prone variants in the immunoglobulin-like domain correlate with domain destabilization. Finally, we demonstrate that myopathic-associated LMNA variants show aggregation patterns in induced pluripotent stem cell derived-cardiomyocytes (iPSC-CMs) in contrast to non-myopathic LMNA variants. Our data-driven approach (1) reveals that striated muscle laminopathies are predominantly protein misfolding diseases, (2) demonstrates an iPSC-CM experimental platform for characterizing laminopathic variants in human cardiomyocytes, and (3) supports a functional assay to aid in assessing pathogenicity for myopathic variants of uncertain significance.
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20
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Hobson CM, Falvo MR, Superfine R. A survey of physical methods for studying nuclear mechanics and mechanobiology. APL Bioeng 2021; 5:041508. [PMID: 34849443 PMCID: PMC8604565 DOI: 10.1063/5.0068126] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Accepted: 10/20/2021] [Indexed: 12/23/2022] Open
Abstract
It is increasingly appreciated that the cell nucleus is not only a home for DNA but also a complex material that resists physical deformations and dynamically responds to external mechanical cues. The molecules that confer mechanical properties to nuclei certainly contribute to laminopathies and possibly contribute to cellular mechanotransduction and physical processes in cancer such as metastasis. Studying nuclear mechanics and the downstream biochemical consequences or their modulation requires a suite of complex assays for applying, measuring, and visualizing mechanical forces across diverse length, time, and force scales. Here, we review the current methods in nuclear mechanics and mechanobiology, placing specific emphasis on each of their unique advantages and limitations. Furthermore, we explore important considerations in selecting a new methodology as are demonstrated by recent examples from the literature. We conclude by providing an outlook on the development of new methods and the judicious use of the current techniques for continued exploration into the role of nuclear mechanobiology.
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Affiliation(s)
| | - Michael R. Falvo
- Department of Physics and Astronomy, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
| | - Richard Superfine
- Department of Applied Physical Science, The University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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21
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Coombs GS, Rios-Monterrosa JL, Lai S, Dai Q, Goll AC, Ketterer MR, Valdes MF, Uche N, Benjamin IJ, Wallrath LL. Modulation of muscle redox and protein aggregation rescues lethality caused by mutant lamins. Redox Biol 2021; 48:102196. [PMID: 34872044 PMCID: PMC8646998 DOI: 10.1016/j.redox.2021.102196] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Accepted: 11/19/2021] [Indexed: 12/28/2022] Open
Abstract
Mutations in the human LMNA gene cause a collection of diseases called laminopathies, which includes muscular dystrophy and dilated cardiomyopathy. The LMNA gene encodes lamins, filamentous proteins that form a meshwork on the inner side of the nuclear envelope. How mutant lamins cause muscle disease is not well understood, and treatment options are currently limited. To understand the pathological functions of mutant lamins so that therapies can be developed, we generated new Drosophila models and human iPS cell-derived cardiomyocytes. In the Drosophila models, muscle-specific expression of the mutant lamins caused nuclear envelope defects, cytoplasmic protein aggregation, activation of the Nrf2/Keap1 redox pathway, and reductive stress. These defects reduced larval motility and caused death at the pupal stage. Patient-derived cardiomyocytes expressing mutant lamins showed nuclear envelope deformations. The Drosophila models allowed for genetic and pharmacological manipulations at the organismal level. Genetic interventions to increase autophagy, decrease Nrf2/Keap1 signaling, or lower reducing equivalents partially suppressed the lethality caused by mutant lamins. Moreover, treatment of flies with pamoic acid, a compound that inhibits the NADPH-producing malic enzyme, partially suppressed lethality. Taken together, these studies have identified multiple new factors as potential therapeutic targets for LMNA-associated muscular dystrophy.
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Affiliation(s)
- Gary S Coombs
- Biology Department, Waldorf University, Forest City, IA, USA
| | | | - Shuping Lai
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Qiang Dai
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Ashley C Goll
- Department of Biochemistry & Molecular Biology, University of Iowa, Iowa City, IA, USA
| | - Margaret R Ketterer
- Department of Biochemistry & Molecular Biology, University of Iowa, Iowa City, IA, USA
| | - Maria F Valdes
- Biology Department, Waldorf University, Forest City, IA, USA
| | - Nnamdi Uche
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA; Department of Physiology, Medical College of Wisconsin, Milwaukee, WO, USA
| | - Ivor J Benjamin
- Cardiovascular Center, Medical College of Wisconsin, Milwaukee, WI, USA
| | - Lori L Wallrath
- Department of Biochemistry & Molecular Biology, University of Iowa, Iowa City, IA, USA.
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22
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Preclinical Advances of Therapies for Laminopathies. J Clin Med 2021; 10:jcm10214834. [PMID: 34768351 PMCID: PMC8584472 DOI: 10.3390/jcm10214834] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 11/29/2022] Open
Abstract
Laminopathies are a group of rare disorders due to mutation in LMNA gene. Depending on the mutation, they may affect striated muscles, adipose tissues, nerves or are multisystemic with various accelerated ageing syndromes. Although the diverse pathomechanisms responsible for laminopathies are not fully understood, several therapeutic approaches have been evaluated in patient cells or animal models, ranging from gene therapies to cell and drug therapies. This review is focused on these therapies with a strong focus on striated muscle laminopathies and premature ageing syndromes.
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23
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Lu JZ, Qiao ZB, Zhang L, Cao HX, Bai ZH, Qi YY, Zhu HY, Chen YQ, Zhang SM, Yan XH, Bao Y, Jia WW, Liu ZM. Generation of a laminopathies-specific iPSC line EHTJUi005-A-3 with homozygous knockout of the LMNA gene by CRISPR/Cas9 technology. Stem Cell Res 2021; 56:102530. [PMID: 34507144 DOI: 10.1016/j.scr.2021.102530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Revised: 08/18/2021] [Accepted: 08/31/2021] [Indexed: 11/28/2022] Open
Abstract
LAMIN A/C, encoded by the LMNA gene, supports the normal structure of the cell nucleus and regulates the connection between the nucleus and the cytoskeleton as a component of the nucleus envelope. The loss of expression and function of the LMNA gene would lead to the occurrence of congenital muscular dystrophy and Emery-Dreifuss muscular dystrophy which are collectively named as laminopathies. Here, we report a human induced pluripotent stem cell (iPSC) line (EHTJUi005-A-3) generated from a wild iPSC (EHTJUi005-A) with homozygous knockout of the gene LMNA through CRISPR/Cas9. This iPSC line provides a useful research model for studying laminopathies disease.
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Affiliation(s)
- Ji-Zhen Lu
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Zhi-Bin Qiao
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Lu Zhang
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Hong-Xia Cao
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Zhi-Hui Bai
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Yi-Yao Qi
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Han-Yu Zhu
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Ya-Qi Chen
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Shou-Mei Zhang
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Xiu-Hua Yan
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Yan Bao
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China
| | - Wen-Wen Jia
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China.
| | - Zhong-Min Liu
- Institute for Regenerative Medicine, National Stem Cell Translational Resource Center, Shanghai East Hospital, School of Life Sciences and Technology, Tongji University, Shanghai 200092, China.
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24
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Ross JA, Stroud MJ. THE NUCLEUS: Mechanosensing in cardiac disease. Int J Biochem Cell Biol 2021; 137:106035. [PMID: 34242685 DOI: 10.1016/j.biocel.2021.106035] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 11/17/2022]
Abstract
The nucleus provides a physical and selective chemical boundary to segregate the genome from the cytoplasm. The contents of the nucleus are surrounded by the nuclear envelope, which acts as a hub of mechanosensation, transducing forces from the external cytoskeleton to the nucleus, thus impacting on nuclear morphology, genome organisation, gene transcription and signalling pathways. Muscle tissues such as the heart are unique in that they actively generate large contractile forces, resulting in a distinctive mechanical environment which impacts nuclear properties, function and mechanosensing. In light of this, mutations that affect the function of the nuclear envelope (collectively known as nuclear envelopathies and laminopathies) disproportionately result in striated muscle diseases, which include dilated and arrhythmogenic cardiomyopathies. Here we review the nucleus and its role in mechanotransduction, as well as associated defects that lead to cardiac dysfunction.
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Affiliation(s)
- Jacob A Ross
- British Heart Foundation Centre of Excellence, School of Cardiovascular Medicine and Sciences, King's College London, London, UK
| | - Matthew J Stroud
- British Heart Foundation Centre of Excellence, School of Cardiovascular Medicine and Sciences, King's College London, London, UK.
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25
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Reynolds N, McEvoy E, Ghosh S, Panadero Pérez JA, Neu CP, McGarry P. Image-derived modeling of nucleus strain amplification associated with chromatin heterogeneity. Biophys J 2021; 120:1323-1332. [PMID: 33675762 PMCID: PMC8105730 DOI: 10.1016/j.bpj.2021.01.040] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 12/17/2020] [Accepted: 01/22/2021] [Indexed: 12/12/2022] Open
Abstract
Beyond the critical role of cell nuclei in gene expression and DNA replication, they also have a significant influence on cell mechanosensation and migration. Nuclear stiffness can impact force transmission and, furthermore, act as a physical barrier to translocation across tight spaces. As such, it is of wide interest to accurately characterize nucleus mechanical behavior. In this study, we present a computational investigation of the in situ deformation of a heterogeneous chondrocyte nucleus. A methodology is developed to accurately reconstruct a three-dimensional finite-element model of a cell nucleus from confocal microscopy. By incorporating the reconstructed nucleus into a chondrocyte model embedded in pericellular and extracellular matrix, we explore the relationship between spatially heterogeneous nuclear DNA content, shear stiffness, and resultant shear strain. We simulate an externally applied extracellular matrix shear deformation and compute intranuclear strain distributions, which are directly compared with corresponding experimentally measured distributions. Simulations suggest that the mechanical behavior of the nucleus is highly heterogeneous, with a nonlinear relationship between experimentally measured grayscale values and corresponding local shear moduli (μn). Three distinct phases are identified within the nucleus: a low-stiffness mRNA-rich interchromatin phase (0.17 kPa ≤ μn ≤ 0.63 kPa), an intermediate-stiffness euchromatin phase (1.48 kPa ≤ μn ≤ 2.7 kPa), and a high-stiffness heterochromatin phase (3.58 kPa ≤ μn ≤ 4.0 kPa). Our simulations also indicate that disruption of the nuclear envelope associated with lamin A/C depletion significantly increases nuclear strain in regions of low DNA concentration. We further investigate a phenotypic shift of chondrocytes to fibroblast-like cells, a signature for osteoarthritic cartilage, by increasing the contractility of the actin cytoskeleton to a level associated with fibroblasts. Peak nucleus strains increase by 35% compared to control, with the nucleus becoming more ellipsoidal. Our findings may have broad implications for current understanding of how local DNA concentrations and associated strain amplification can impact cell mechanotransduction and drive cell behavior in development, migration, and tumorigenesis.
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Affiliation(s)
- Noel Reynolds
- Biomedical Engineering, National University of Ireland Galway, Galway, Ireland
| | - Eoin McEvoy
- Biomedical Engineering, National University of Ireland Galway, Galway, Ireland
| | - Soham Ghosh
- Mechanical Engineering, Colorado State University, Fort Collins, Colorado
| | | | - Corey P Neu
- Mechanical Engineering, University of Colorado Boulder, Boulder, Colorado
| | - Patrick McGarry
- Biomedical Engineering, National University of Ireland Galway, Galway, Ireland.
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26
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Parry DA, Martin CA, Greene P, Marsh JA, Blyth M, Cox H, Donnelly D, Greenhalgh L, Greville-Heygate S, Harrison V, Lachlan K, McKenna C, Quigley AJ, Rea G, Robertson L, Suri M, Jackson AP. Heterozygous lamin B1 and lamin B2 variants cause primary microcephaly and define a novel laminopathy. Genet Med 2021; 23:408-414. [PMID: 33033404 PMCID: PMC7862057 DOI: 10.1038/s41436-020-00980-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Revised: 09/14/2020] [Accepted: 09/17/2020] [Indexed: 11/25/2022] Open
Abstract
PURPOSE Lamins are the major component of nuclear lamina, maintaining structural integrity of the nucleus. Lamin A/C variants are well established to cause a spectrum of disorders ranging from myopathies to progeria, termed laminopathies. Phenotypes resulting from variants in LMNB1 and LMNB2 have been much less clearly defined. METHODS We investigated exome and genome sequencing from the Deciphering Developmental Disorders Study and the 100,000 Genomes Project to identify novel microcephaly genes. RESULTS Starting from a cohort of patients with extreme microcephaly, 13 individuals with heterozygous variants in the two human B-type lamins were identified. Recurrent variants were established to be de novo in nine cases and shown to affect highly conserved residues within the lamin ɑ-helical rod domain, likely disrupting interactions required for higher-order assembly of lamin filaments. CONCLUSION We identify dominant pathogenic variants in LMNB1 and LMNB2 as a genetic cause of primary microcephaly, implicating a major structural component of the nuclear envelope in its etiology and defining a new form of laminopathy. The distinct nature of this lamin B-associated phenotype highlights the strikingly different developmental requirements for lamin paralogs and suggests a novel mechanism for primary microcephaly warranting future investigation.
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Affiliation(s)
- David A Parry
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Carol-Anne Martin
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Philip Greene
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Joseph A Marsh
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK
| | - Moira Blyth
- Yorkshire Regional Genetics Service, Leeds Teaching Hospitals NHS Trust, Department of Clinical Genetics, Chapel Allerton Hospital, Leeds, UK
| | - Helen Cox
- West Midlands Regional Genetics Service, Birmingham Women's NHS Foundation Trust, Birmingham Women's Hospital, Edgbaston, Birmingham, UK
| | - Deirdre Donnelly
- Northern Ireland Regional Genetics Service, Belfast City Hospital, Belfast, UK
| | - Lynn Greenhalgh
- Liverpool Centre for Genomic Medicine, Liverpool Women's Hospital, Liverpool, UK
| | - Stephanie Greville-Heygate
- Faculty of Medicine, University of Southampton, Southampton, UK
- Wessex Clinical Genetics Service, University Hospital Southampton, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Victoria Harrison
- Wessex Clinical Genetics Service, Princess Anne Hospital, University Hospital Southampton NHS Foundation Trust, Southampton, UK
| | - Katherine Lachlan
- Wessex Clinical Genetics Service, University Hospital Southampton, University Hospital Southampton NHS Foundation Trust, Southampton, UK
- Human Development and Health, Faculty of Medicine, University of Southampton, Southampton, UK
| | - Caoimhe McKenna
- Northern Ireland Regional Genetics Service, Belfast City Hospital, Belfast, UK
| | - Alan J Quigley
- Department of Radiology, Royal Hospital for Sick Children, Edinburgh, UK
| | - Gillian Rea
- Northern Ireland Regional Genetics Service, Belfast City Hospital, Belfast, UK
| | - Lisa Robertson
- Department of Clinical Genetics, Aberdeen Royal Infirmary, Scotland, UK
| | - Mohnish Suri
- Clinical Genetics Service, Nottingham University Hospitals NHS Trust, City Hospital Campus, Nottingham, UK
| | - Andrew P Jackson
- MRC Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, UK.
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27
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LINC complex regulation of genome organization and function. Curr Opin Genet Dev 2021; 67:130-141. [PMID: 33524904 DOI: 10.1016/j.gde.2020.12.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Revised: 11/25/2020] [Accepted: 12/11/2020] [Indexed: 12/28/2022]
Abstract
The regulation of genomic function is in part mediated through the physical organization and architecture of the nucleus. Disruption to nuclear organization and architecture is increasingly being recognized by its contribution to many diseases. The LINC complexes - protein structures traversing the nuclear envelope, that physically connect the nuclear interior, and hence the genome, to cytoplasmic cytoskeletal networks are an important component in the physical organization of the genome and its function. This connection, potentially allows for the constant detection of environmental mechanical stimuli, resulting in altered regulation of nuclear architecture and genome function, either directly or via the process of mechanotransduction. Here, we review the influences LINC complexes exert on genome functions and their impact on cellular/organismal health.
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28
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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: 7] [Impact Index Per Article: 1.8] [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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29
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Actin on and around the Nucleus. Trends Cell Biol 2020; 31:211-223. [PMID: 33376040 DOI: 10.1016/j.tcb.2020.11.009] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 11/15/2020] [Accepted: 11/19/2020] [Indexed: 12/14/2022]
Abstract
Actin plays roles in many important cellular processes, including cell motility, organelle movement, and cell signaling. The discovery of transmembrane actin-binding proteins at the outer nuclear membrane (ONM) raises the exciting possibility that actin can play a role in direct force transmission to the nucleus and the genome at its interior. Actin-dependent nucleus displacement was first described a decade ago. We are now gaining a more detailed understanding of its mechanisms, as well as new roles for actin during mitosis and meiosis, for gene expression, and in the cell's response to mechanical stimuli. Here we review these recent developments, the actin-binding proteins involved, the tissue specificity of these mechanisms, and methods developed to reconstitute and study this interaction in vitro.
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30
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Steering cell behavior through mechanobiology in 3D: A regenerative medicine perspective. Biomaterials 2020; 268:120572. [PMID: 33285439 DOI: 10.1016/j.biomaterials.2020.120572] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 09/04/2020] [Accepted: 11/21/2020] [Indexed: 12/14/2022]
Abstract
Mechanobiology, translating mechanical signals into biological ones, greatly affects cellular behavior. Steering cellular behavior for cell-based regenerative medicine approaches requires a thorough understanding of the orchestrating molecular mechanisms, among which mechanotransducive ones are being more and more elucidated. Because of their wide use and highly mechanotransduction dependent differentiation, this review focuses on mesenchymal stromal cells (MSCs), while also briefly relating the discussed results to other cell types. While the mechanotransduction pathways are relatively well-studied in 2D, much remains unknown of the role and regulation of these pathways in 3D. Ultimately, cells need to be cultured in a 3D environment to create functional de novo tissue. In this review, we explore the literature on the roles of different material properties on cellular behavior and mechanobiology in 2D and 3D. For example, while stiffness plays a dominant role in 2D MSCs differentiation, it seems to be of subordinate importance in 3D MSCs differentiation, where matrix remodeling seems to be key. Also, the role and regulation of some of the main mechanotransduction players are discussed, focusing on MSCs. We have only just begun to fundamentally understand MSCs and other stem cells behavior in 3D and more fundamental research is required to advance biomaterials able to replicate the stem cell niche and control cell activity. This better understanding will contribute to smarter tissue engineering scaffold design and the advancement of regenerative medicine.
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31
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Nicolas HA, Bertrand AT, Labib S, Mohamed-Uvaize M, Bolongo PM, Wu WY, Bilińska ZT, Bonne G, Akimenko MA, Tesson F. Protein Kinase C Alpha Cellular Distribution, Activity, and Proximity with Lamin A/C in Striated Muscle Laminopathies. Cells 2020; 9:cells9112388. [PMID: 33142761 PMCID: PMC7693451 DOI: 10.3390/cells9112388] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 10/19/2020] [Accepted: 10/28/2020] [Indexed: 11/24/2022] Open
Abstract
Striated muscle laminopathies are cardiac and skeletal muscle conditions caused by mutations in the lamin A/C gene (LMNA). LMNA codes for the A-type lamins, which are nuclear intermediate filaments that maintain the nuclear structure and nuclear processes such as gene expression. Protein kinase C alpha (PKC-α) interacts with lamin A/C and with several lamin A/C partners involved in striated muscle laminopathies. To determine PKC-α’s involvement in muscular laminopathies, PKC-α’s localization, activation, and interactions with the A-type lamins were examined in various cell types expressing pathogenic lamin A/C mutations. The results showed aberrant nuclear PKC-α cellular distribution in mutant cells compared to WT. PKC-α activation (phos-PKC-α) was decreased or unchanged in the studied cells expressing LMNA mutations, and the activation of its downstream targets, ERK 1/2, paralleled PKC-α activation alteration. Furthermore, the phos-PKC-α-lamin A/C proximity was altered. Overall, the data showed that PKC-α localization, activation, and proximity with lamin A/C were affected by certain pathogenic LMNA mutations, suggesting PKC-α involvement in striated muscle laminopathies.
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Affiliation(s)
- Hannah A. Nicolas
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (H.A.N.); (W.Y.W.); (M.-A.A.)
| | - Anne T. Bertrand
- Sorbonne Université, Inserm, Centre de Recherche en Myologie, UMRS 974, G.H. Pitié-Salpêtrière, 75013 Paris, France; (A.T.B.); (G.B.)
| | - Sarah Labib
- Interdisciplinary School of Health Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (S.L.); (M.M.-U.); (P.M.B.)
| | - Musfira Mohamed-Uvaize
- Interdisciplinary School of Health Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (S.L.); (M.M.-U.); (P.M.B.)
| | - Pierrette M. Bolongo
- Interdisciplinary School of Health Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (S.L.); (M.M.-U.); (P.M.B.)
| | - Wen Yu Wu
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (H.A.N.); (W.Y.W.); (M.-A.A.)
| | - Zofia T. Bilińska
- Unit for Screening Studies in Inherited Cardiovascular Diseases, National Institute of Cardiology, 04-628 Warsaw, Poland;
| | - Gisèle Bonne
- Sorbonne Université, Inserm, Centre de Recherche en Myologie, UMRS 974, G.H. Pitié-Salpêtrière, 75013 Paris, France; (A.T.B.); (G.B.)
| | - Marie-Andrée Akimenko
- Department of Biology, Faculty of Science, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (H.A.N.); (W.Y.W.); (M.-A.A.)
| | - Frédérique Tesson
- Interdisciplinary School of Health Sciences, Faculty of Health Sciences, University of Ottawa, Ottawa, ON K1N 6N5, Canada; (S.L.); (M.M.-U.); (P.M.B.)
- Correspondence: ; Tel.: +1-613-562-5800 (ext. 7370)
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32
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Abstract
The nuclear envelope is often depicted as a static barrier that regulates access between the nucleus and the cytosol. However, recent research has identified many conditions in cultured cells and in vivo in which nuclear membrane ruptures cause the loss of nuclear compartmentalization. These conditions include some that are commonly associated with human disease, such as migration of cancer cells through small spaces and expression of nuclear lamin disease mutations in both cultured cells and tissues undergoing nuclear migration. Nuclear membrane ruptures are rapidly repaired in the nucleus but persist in nuclear compartments that form around missegregated chromosomes called micronuclei. This review summarizes what is known about the mechanisms of nuclear membrane rupture and repair in both the main nucleus and micronuclei, and highlights recent work connecting the loss of nuclear integrity to genome instability and innate immune signaling. These connections link nuclear membrane rupture to complex chromosome alterations, tumorigenesis, and laminopathy etiologies.
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Affiliation(s)
- John Maciejowski
- Molecular Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10065, USA;
| | - Emily M Hatch
- Division of Basic Sciences and Human Biology, The Fred Hutchinson Cancer Research Center, Seattle, Washington 98109, USA;
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33
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Nuclear mechanosensing: mechanism and consequences of a nuclear rupture. Mutat Res 2020; 821:111717. [PMID: 32810711 DOI: 10.1016/j.mrfmmm.2020.111717] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 06/25/2020] [Accepted: 07/14/2020] [Indexed: 12/22/2022]
Abstract
The physical connections between the cytoskeletal system and the nucleus provide a route for the nucleus to sense the mechanical stress both inside and outside of the cell. Failure to withstand such stress leads to nuclear rupture, which is observed in human diseases. In this review, we will go through the recent findings and our current understandings of nuclear rupture. Starting with the triggers of nuclear rupture, including the aberrant nuclear lamina composition and the elevated actomyosin contractility. We will also discuss the role of ESCRT-III in nuclear rupture repair and the biological consequences of nuclear rupture, including the negative impacts on cellular compartmentalization, DNA damage, and cellular differentiation. Recent studies on nuclear rupture provide further insights into the direct mechanistic link between nuclear rupture and several pathological conditions. Such knowledge can guide us in developing potential therapeutic solutions for the patients.
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34
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Piccus R, Brayson D. The nuclear envelope: LINCing tissue mechanics to genome regulation in cardiac and skeletal muscle. Biol Lett 2020; 16:20200302. [PMID: 32634376 DOI: 10.1098/rsbl.2020.0302] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Regulation of the genome is viewed through the prism of gene expression, DNA replication and DNA repair as controlled through transcription, chromatin compartmentalisation and recruitment of repair factors by enzymes such as DNA polymerases, ligases, acetylases, methylases and cyclin-dependent kinases. However, recent advances in the field of muscle cell physiology have also shown a compelling role for 'outside-in' biophysical control of genomic material through mechanotransduction. The crucial hub that transduces these biophysical signals is called the Linker of Nucleoskeleton and Cytoskeleton (LINC). This complex is embedded across the nuclear envelope, which separates the nucleus from the cytoplasm. How the LINC complex operates to mechanically regulate the many functions of DNA is becoming increasingly clear, and recent advances have provided exciting insight into how this occurs in cells from mechanically activated tissues such as skeletal and cardiac muscle. Nevertheless, there are still some notable shortcomings in our understanding of these processes and resolving these will likely help us understand how muscle diseases manifest at the level of the genome.
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Affiliation(s)
- Rachel Piccus
- Centre for Human and Applied Physiological Sciences, King's College London, London SE1 1UL, UK
| | - Daniel Brayson
- School of Cardiovascular Medicine and Sciences, King's College London, London SE5 9NU, UK.,Molecular Neurosciences, UCL Great Ormond Street Institute of Child Health, 30 Guilford Street, London WC1N 1EH, UK
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35
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Ghosh S, Seelbinder B, Henderson JT, Watts RD, Scott AK, Veress AI, Neu CP. Deformation Microscopy for Dynamic Intracellular and Intranuclear Mapping of Mechanics with High Spatiotemporal Resolution. Cell Rep 2020; 27:1607-1620.e4. [PMID: 31042484 PMCID: PMC8769958 DOI: 10.1016/j.celrep.2019.04.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Revised: 01/10/2019] [Accepted: 04/01/2019] [Indexed: 12/14/2022] Open
Abstract
Structural heterogeneity is a hallmark of living cells that drives local mechanical properties and dynamic cellular responses. However, the robust quantification of intracellular mechanics is lacking from conventional methods. Here, we describe the development of deformation microscopy, which leverages conventional imaging and an automated hyperelastic warping algorithm to investigate strain history, deformation dynamics, and changes in structural heterogeneity within the interior of cells and cell nuclei. Using deformation microscopy, we found that partial or complete disruption of LINC complexes in cardiomyocytes in vitro and lamin A/C deficiency in myocytes in vivo abrogate dominant tensile loading in the nuclear interior. We also found that cells cultured on stiff substrates or in hyperosmotic conditions displayed abnormal strain burden and asymmetries at interchromatin regions, which are associated with active transcription. Deformation microscopy represents a foundational approach toward intracellular elastography, with the potential utility to provide mechanistic and quantitative insights in diverse mechanobiological applications. Ghosh et al. show that deformation microscopy, a technique based on image analysis and mechanics, reveals deformation dynamics and structural heterogeneity changes for several applications and at multiple scales, including tissues, cells, and nuclei. They reveal how the disruption of nuclear proteins and pathological conditions abrogate mechanical strain in the nuclear interior.
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Affiliation(s)
- Soham Ghosh
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Benjamin Seelbinder
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Jonathan T Henderson
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Ryan D Watts
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA
| | - Adrienne K Scott
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA
| | - Alexander I Veress
- Department of Mechanical Engineering, University of Washington, Seattle, WA, USA
| | - Corey P Neu
- Department of Mechanical Engineering, University of Colorado Boulder, Boulder, CO, USA; Weldon School of Biomedical Engineering, Purdue University, West Lafayette, IN, USA.
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36
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Tran RDH, Siemens M, Nguyen CHH, Ochs AR, Zaragoza MV, Grosberg A. The Effect of Cyclic Strain on Human Fibroblasts With Lamin A/C Mutations and Its Relation to Heart Disease. J Biomech Eng 2020; 142:2737114. [PMID: 31233093 DOI: 10.1115/1.4044091] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Indexed: 12/26/2022]
Abstract
Although mutations in the Lamin A/C gene (LMNA) cause a variety of devastating diseases, the pathological mechanism is often unknown. Lamin A/C proteins play a crucial role in forming a meshwork under the nuclear membrane, providing the nucleus with mechanical integrity and interacting with other proteins for gene regulation. Most LMNA mutations result in heart diseases, including some types that primarily have heart disease as the main pathology. In this study, we used cells from patients with different LMNA mutations that primarily lead to heart disease. Indeed, it is a mystery why a mutation to the protein in every nucleus of the body manifests as a disease of primarily the heart in these patients. Here, we aimed to investigate if strains mimicking those within the myocardial environment are sufficient to cause differences in cells with and without the LMNA mutation. To test this, a stretcher device was used to induce cyclic strain upon cells, and viability/proliferation, cytoskeleton and extracellular matrix organization, and nuclear morphology were quantified. The properties of cells with Hutchinson-Gilford progeria syndrome (HGPS) were found to be significantly different from all other cell lines and were mostly in line with previous findings. However, the properties of cells from patients who primarily had heart diseases were not drastically different when compared to individuals without the LMNA mutation. Our results indicated that cyclic strain alone was insufficient to cause any significant differences that could explain the mechanisms that lead to heart diseases in these patients with LMNA mutations.
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Affiliation(s)
- Richard D H Tran
- Cardiovascular Modeling Laboratory, The Edwards Lifesciences Center for Advanced Cardiovascular Technology, Department of Biomedical Engineering, University of California, 2131 Engineering Hall Irvine, Irvine, CA 92697-2700
| | - Mark Siemens
- Cardiovascular Modeling Laboratory, The Edwards Lifesciences Center for Advanced Cardiovascular Technology, Department of Biomedical Engineering, University of California, 2131 Engineering Hall Irvine, Irvine, CA 92697-2700
| | - Cecilia H H Nguyen
- Division of Genetics and Genomics, Department of Pediatrics, School of Medicine, University of California, 2042 Hewitt Hall Irvine, Irvine, CA 92697-3940
| | - Alexander R Ochs
- Cardiovascular Modeling Laboratory, The Edwards Lifesciences Center for Advanced Cardiovascular Technology, Department of Biomedical Engineering, University of California, 2131 Engineering Hall Irvine, Irvine, CA 92697-2700
| | - Michael V Zaragoza
- Department of Pediatrics, Division of Genetics & Genomics, 2042 Hewitt Hall Irvine, Irvine, CA 92697-3940; Department of Biological Chemistry, University of California, School of Medicine, 2042 Hewitt Hall Irvine, Irvine, CA 92697-3940
| | - Anna Grosberg
- Cardiovascular Modeling Laboratory, The Edwards Lifesciences Center for Advanced Cardiovascular Technology, Center for Complex Biological Systems, Department of Biomedical Engineering, University of California, 2418 Engineering Hall Irvine, Irvine, CA 92697-2700; Department of Chemical and Biomolecular Engineering, University of California, 2418 Engineering Hall Irvine, Irvine, CA 92697-2700
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37
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Earle AJ, Kirby TJ, Fedorchak GR, Isermann P, Patel J, Iruvanti S, Moore SA, Bonne G, Wallrath LL, Lammerding J. Mutant lamins cause nuclear envelope rupture and DNA damage in skeletal muscle cells. NATURE MATERIALS 2020; 19:464-473. [PMID: 31844279 PMCID: PMC7102937 DOI: 10.1038/s41563-019-0563-5] [Citation(s) in RCA: 125] [Impact Index Per Article: 31.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2019] [Accepted: 11/12/2019] [Indexed: 05/19/2023]
Abstract
Mutations in the LMNA gene, which encodes the nuclear envelope (NE) proteins lamins A/C, cause Emery-Dreifuss muscular dystrophy, congenital muscular dystrophy and other diseases collectively known as laminopathies. The mechanisms responsible for these diseases remain incompletely understood. Using three mouse models of muscle laminopathies and muscle biopsies from individuals with LMNA-related muscular dystrophy, we found that Lmna mutations reduced nuclear stability and caused transient rupture of the NE in skeletal muscle cells, resulting in DNA damage, DNA damage response activation and reduced cell viability. NE and DNA damage resulted from nuclear migration during skeletal muscle maturation and correlated with disease severity in the mouse models. Reduction of cytoskeletal forces on the myonuclei prevented NE damage and rescued myofibre function and viability in Lmna mutant myofibres, indicating that myofibre dysfunction is the result of mechanically induced NE damage. Taken together, these findings implicate mechanically induced DNA damage as a pathogenic contributor to LMNA skeletal muscle diseases.
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Affiliation(s)
- Ashley J Earle
- Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Tyler J Kirby
- Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Gregory R Fedorchak
- Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Philipp Isermann
- Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Jineet Patel
- Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Sushruta Iruvanti
- Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA
| | - Steven A Moore
- Department of Pathology, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Gisèle Bonne
- Sorbonne Université, Inserm UMRS 974, Center of Research in Myology, Association Institute of Myology, Paris, France
| | - Lori L Wallrath
- Department of Biochemistry, Carver College of Medicine, University of Iowa, Iowa City, IA, USA
| | - Jan Lammerding
- Meinig School of Biomedical Engineering & Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY, USA.
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38
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Lamin A/C Assembly Defects in LMNA-Congenital Muscular Dystrophy Is Responsible for the Increased Severity of the Disease Compared with Emery-Dreifuss Muscular Dystrophy. Cells 2020; 9:cells9040844. [PMID: 32244403 PMCID: PMC7226786 DOI: 10.3390/cells9040844] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 03/24/2020] [Accepted: 03/27/2020] [Indexed: 01/13/2023] Open
Abstract
LMNA encodes for Lamin A/C, type V intermediate filaments that polymerize under the inner nuclear membrane to form the nuclear lamina. A small fraction of Lamin A/C, less polymerized, is also found in the nucleoplasm. Lamin A/C functions include roles in nuclear resistance to mechanical stress and gene regulation. LMNA mutations are responsible for a wide variety of pathologies, including Emery–Dreifuss (EDMD) and LMNA-related congenital muscular dystrophies (L-CMD) without clear genotype–phenotype correlations. Both diseases presented with striated muscle disorders although L-CMD symptoms appear much earlier and are more severe. Seeking for pathomechanical differences to explain the severity of L-CMD mutations, we performed an in silico analysis of the UMD-LMNA database and found that L-CMD mutations mainly affect residues involved in Lamin dimer and tetramer stability. In line with this, we found increased nucleoplasmic Lamin A/C in L-CMD patient fibroblasts and mouse myoblasts compared to the control and EDMD. L-CMD myoblasts show differentiation defects linked to their inability to upregulate muscle specific nuclear envelope (NE) proteins expression. NE proteins were mislocalized, leading to misshapen nuclei. We conclude that these defects are due to both the absence of Lamin A/C from the nuclear lamina and its maintenance in the nucleoplasm of myotubes.
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39
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Owens DJ, Fischer M, Jabre S, Moog S, Mamchaoui K, Butler-Browne G, Coirault C. Lamin Mutations Cause Increased YAP Nuclear Entry in Muscle Stem Cells. Cells 2020; 9:cells9040816. [PMID: 32231000 PMCID: PMC7226749 DOI: 10.3390/cells9040816] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 03/24/2020] [Accepted: 03/24/2020] [Indexed: 01/17/2023] Open
Abstract
Mutations in the LMNA gene, encoding the nuclear envelope A-type lamins, are responsible for muscular dystrophies, the most severe form being the LMNA-related congenital muscular dystrophy (L-CMD), with severe defects in myonucleus integrity. We previously reported that L-CMD mutations compromise the ability of muscle stem cells to modulate the yes-associated protein (YAP), a pivotal factor in mechanotransduction and myogenesis. Here, we investigated the intrinsic mechanisms by which lamins influence YAP subcellular distribution, by analyzing different conditions affecting the balance between nuclear import and export of YAP. In contrast to wild type (WT) cells, LMNADK32 mutations failed to exclude YAP from the nucleus and to inactivate its transcriptional activity at high cell density, despite activation of the Hippo pathway. Inhibiting nuclear pore import abolished YAP nuclear accumulation in confluent mutant cells, thus showing persistent nuclear import of YAP at cell confluence. YAP deregulation was also present in congenital myopathy related to nesprin-1 KASH mutation, but not in cells expressing the LMNAH222P mutation, the adult form of lamin-related muscle dystrophy with reduced nuclear deformability. In conclusion, our data showed that L-CMD mutations increased YAP nuclear localization via an increased nuclear import and implicated YAP as a pathogenic contributor in muscle dystrophies caused by nuclear envelop defects.
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Affiliation(s)
- Daniel J. Owens
- INSERM UMRS_974, Centre for Research in Myology, Sorbonne Université, 75013 Paris, France; (D.J.O.); (M.F.); (S.J.); (G.B.-B.)
- Research Institute for Sport and Exercise Science, Liverpool John Moores University, Liverpool L3 3AF, UK
| | - Martina Fischer
- INSERM UMRS_974, Centre for Research in Myology, Sorbonne Université, 75013 Paris, France; (D.J.O.); (M.F.); (S.J.); (G.B.-B.)
| | - Saline Jabre
- INSERM UMRS_974, Centre for Research in Myology, Sorbonne Université, 75013 Paris, France; (D.J.O.); (M.F.); (S.J.); (G.B.-B.)
| | | | | | - Gillian Butler-Browne
- INSERM UMRS_974, Centre for Research in Myology, Sorbonne Université, 75013 Paris, France; (D.J.O.); (M.F.); (S.J.); (G.B.-B.)
| | - Catherine Coirault
- INSERM UMRS_974, Centre for Research in Myology, Sorbonne Université, 75013 Paris, France; (D.J.O.); (M.F.); (S.J.); (G.B.-B.)
- Correspondence: ; Tel.: +33-142-16-57-08
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40
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Shimizu A, Zankov DP, Sato A, Komeno M, Toyoda F, Yamazaki S, Makita T, Noda T, Ikawa M, Asano Y, Miyashita Y, Takashima S, Morita H, Ishikawa T, Makita N, Hitosugi M, Matsuura H, Ohno S, Horie M, Ogita H. Identification of transmembrane protein 168 mutation in familial Brugada syndrome. FASEB J 2020; 34:6399-6417. [PMID: 32175648 DOI: 10.1096/fj.201902991r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 02/19/2020] [Accepted: 03/02/2020] [Indexed: 12/30/2022]
Abstract
Brugada syndrome (BrS) is an inherited channelopathy responsible for almost 20% of sudden cardiac deaths in patients with nonstructural cardiac diseases. Approximately 70% of BrS patients, the causative gene mutation(s) remains unknown. In this study, we used whole exome sequencing to investigate candidate mutations in a family clinically diagnosed with BrS. A heterozygous 1616G>A substitution (R539Q mutation) was identified in the transmembrane protein 168 (TMEM168) gene of symptomatic individuals. Similar to endogenous TMEM168, both TMEM168 wild-type (WT) and mutant proteins that were ectopically induced in HL-1 cells showed nuclear membrane localization. A significant decrease in Na+ current and Nav 1.5 protein expression was observed in HL-1 cardiomyocytes expressing mutant TMEM168. Ventricular tachyarrhythmias and conduction disorders were induced in the heterozygous Tmem168 1616G>A knock-in mice by pharmacological stimulation, but not in WT mice. Na+ current was reduced in ventricular cardiomyocytes isolated from the Tmem168 knock-in heart, and Nav 1.5 expression was also impaired. This impairment was dependent on increased Nedd4-2 binding to Nav 1.5 and subsequent ubiquitination. Collectively, our results show an association between the TMEM168 1616G>A mutation and arrhythmogenesis in a family with BrS.
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Affiliation(s)
- Akio Shimizu
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Otsu, Japan
| | - Dimitar P Zankov
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Otsu, Japan.,Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Akira Sato
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Otsu, Japan
| | - Masahiro Komeno
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Otsu, Japan
| | - Futoshi Toyoda
- Division of Cell Physiology, Department of Physiology, Shiga University of Medical Science, Otsu, Japan
| | - Satoru Yamazaki
- Department of Molecular Pharmacology, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Toshinori Makita
- Division of Cardiac Electrophysiology, Department of Cardiovascular Center, Osaka Red Cross Hospital, Osaka, Japan
| | - Taichi Noda
- Animal Resource Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Masahito Ikawa
- Animal Resource Center for Infectious Diseases, Research Institute for Microbial Diseases, Osaka University, Suita, Japan
| | - Yoshihiro Asano
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Yohei Miyashita
- Department of Legal Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Seiji Takashima
- Department of Medical Biochemistry, Osaka University Graduate School of Medicine, Suita, Japan
| | - Hiroshi Morita
- Department of Cardiovascular Therapeutics, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, Okayama, Japan
| | - Taisuke Ishikawa
- Omics Research Center, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Naomasa Makita
- Omics Research Center, National Cerebral and Cardiovascular Center, Suita, Japan
| | - Masahito Hitosugi
- Department of Legal Medicine, Shiga University of Medical Science, Otsu, Japan
| | - Hiroshi Matsuura
- Division of Cell Physiology, Department of Physiology, Shiga University of Medical Science, Otsu, Japan
| | - Seiko Ohno
- Department of Bioscience and Genetics, National Cerebral and Cardiovascular Center, Suita, Japan.,Center for Epidemiologic Research in Asia, Shiga University of Medical Science, Otsu, Japan
| | - Minoru Horie
- Center for Epidemiologic Research in Asia, Shiga University of Medical Science, Otsu, Japan
| | - Hisakazu Ogita
- Division of Molecular Medical Biochemistry, Department of Biochemistry and Molecular Biology, Shiga University of Medical Science, Otsu, Japan
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41
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Osmanagic-Myers S, Foisner R. The structural and gene expression hypotheses in laminopathic diseases-not so different after all. Mol Biol Cell 2020; 30:1786-1790. [PMID: 31306095 PMCID: PMC6727745 DOI: 10.1091/mbc.e18-10-0672] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Laminopathies are a diverse group of rare diseases with various pathologies in different tissues, which are linked to mutations in the LMNA gene. Historically, the structural disease model proposed mechanical defects of the lamina and nuclear fragility, the gene expression model impairment of spatial chromatin organization and signaling pathways as underlying mechanisms leading to the pathologies. Exciting findings in the past few years showing that mechanical forces are directly transmitted into the nucleus, where they affect chromatin organization and mechanoresponsive signaling molecules, have led to a revised concept of an integrative unified disease model, in which lamin-mediated pathways in mechanotransduction and chromatin regulation are highly interconnected and mutually dependent. In this Perspective we highlight breakthrough findings providing new insight into lamin-linked mechanisms of mechanotransduction and chromatin regulation and discuss how a combined and interrelated impairment of these functions by LMNA mutations may impair the complex mechanosignaling network and cause tissue-specific pathologies in laminopathies.
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Affiliation(s)
- Selma Osmanagic-Myers
- Max F. Perutz Laboratories, Center of Medical Biochemistry, Medical University of Vienna, 1030 Vienna, Austria.,Department of Biotechnology, University of Natural Resources and Life Sciences, 1190 Vienna, Austria
| | - Roland Foisner
- Max F. Perutz Laboratories, Center of Medical Biochemistry, Medical University of Vienna, 1030 Vienna, Austria
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42
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Abstract
PURPOSE OF REVIEW The purpose of this review is to provide an update on lamin A/C (LMNA)-related cardiomyopathy and discuss the current recommendations and progress in the management of this disease. LMNA-related cardiomyopathy, an inherited autosomal dominant disease, is one of the most common causes of dilated cardiomyopathy and is characterized by steady progression toward heart failure and high risks of arrhythmias and sudden cardiac death. RECENT FINDINGS We discuss recent advances in the understanding of the molecular mechanisms of the disease including altered cell biomechanics, which may represent novel therapeutic targets to advance the current management approach, which relies on standard heart failure recommendations. Future therapeutic approaches include repurposed molecularly directed drugs, siRNA-based gene silencing, and genome editing. LMNA-related cardiomyopathy is the focus of active in vitro and in vivo research, which is expected to generate novel biomarkers and identify new therapeutic targets. LMNA-related cardiomyopathy trials are currently underway.
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43
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Koirala M, Alexov E. Computational chemistry methods to investigate the effects caused by DNA variants linked with disease. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2019. [DOI: 10.1142/s0219633619300015] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Computational chemistry offers variety of tools to study properties of biological macromolecules. These tools vary in terms of levels of details from quantum mechanical treatment to numerous macroscopic approaches. Here, we provide a review of computational chemistry algorithms and tools for modeling the effects of genetic variations and their association with diseases. Particular emphasis is given on modeling the effects of missense mutations on stability, conformational dynamics, binding, hydrogen bond network, salt bridges, and pH-dependent properties of the corresponding macromolecules. It is outlined that the disease may be caused by alteration of one or several of above-mentioned biophysical characteristics, and a successful prediction of pathogenicity requires detailed analysis of how the alterations affect the function of involved macromolecules. The review provides a short list of most commonly used algorithms to predict the molecular effects of mutations as well.
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Affiliation(s)
- Mahesh Koirala
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29630, USA
| | - Emil Alexov
- Department of Physics and Astronomy, Clemson University, Clemson, SC 29630, USA
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44
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Abstract
Lamins are evolutionarily conserved nuclear intermediate filament proteins. They provide structural support for the nucleus and help regulate many other nuclear activities. Mutations in human lamin genes, and especially in the LMNA gene, cause numerous diseases, termed laminopathies, including muscle, cardiac, metabolic, neuronal and early aging diseases. Most laminopathies arise from autosomal dominant missense mutations. Many of the mutant residues are conserved in the lamin genes of the nematode Caenorhabditis elegans and the fruit fly Drosophila melanogaster. Our current understanding of the mechanisms leading to these diseases is mostly based on patients cell lines and animal models including C. elegans and D. melanogaster. The simpler lamin system and the powerful genetic tools offered by these invertebrate organisms greatly contributed to such studies. Here we provide an overview of the studies of laminopathies in Drosophila and C. elegans models.
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Affiliation(s)
- Ryszard Rzepecki
- a Laboratory of Nuclear Proteins, Faculty of Biotechnology , University of Wroclaw , Fryderyka Joliot-Curie, Wroclaw , Poland
| | - Yosef Gruenbaum
- a Laboratory of Nuclear Proteins, Faculty of Biotechnology , University of Wroclaw , Fryderyka Joliot-Curie, Wroclaw , Poland.,b Department of Genetics , Institute of Life Sciences, Hebrew University of Jerusalem , Jerusalem , Israel
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45
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Suspension State Promotes Drug Resistance of Breast Tumor Cells by Inducing ABCC3 Overexpression. Appl Biochem Biotechnol 2019; 190:410-422. [PMID: 31367898 DOI: 10.1007/s12010-019-03084-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 07/05/2019] [Indexed: 12/19/2022]
Abstract
Mechanical microenvironment plays a critical role in cancer drug resistance and this study supposed that suspension state might be involved in drug resistance of breast tumor cells. The viability of cell was detected by 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. Cell cycle and apoptosis were detected by flow cytometry. Gene and protein were tested by RT-qPCR and Western blot, respectively. Drug resistance of MDA-MB-231 cells cultured for 72 h under suspension state was significantly increased. Suspension state was found to induce the overexpression of adenosine triphosphate-binding cassette subfamily C member 3 (ABCC3) in MDA-MB-231 cells. Silencing of ABCC3 significantly decreased drug resistance of suspension MDA-MB-231 cells. Moreover, suspension state was able to increase lamin A/C accumulation in MDA-MB-231 cells and lamin A/C regulated the expression of ABCC3. Moreover, lamin A/C knockdown also decreased drug resistance of suspension MDA-MB-231 cells, but the effect on drug resistance was less than that of ABCC3 knockdown. Suspension state plays a vital role in promoting drug resistance of MDA-MB-231 cells by inducing ABCC3 overexpression, and lamin A/C accumulation is associated with this process.
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46
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Ji JY. Endothelial Nuclear Lamina in Mechanotransduction Under Shear Stress. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1097:83-104. [PMID: 30315541 DOI: 10.1007/978-3-319-96445-4_5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Endothelial cells that line the lumen of blood vessels are at the interface between hemodynamic forces and vascular wall biology. Endothelial cells transduce mechanical and biological signals from blood flow into intracellular signaling cascades through a process called mechanotransduction. Mechanotransduction is an important part of normal cell functions, as well as endothelial dysfunction which leads to inflammation and pathological conditions. For example, atherosclerosis preferentially develops in regions of disturbed fluid flow and low shear stress. The nuclear lamina, which sits underneath the nuclear envelope, serves to maintain the nuclear structure while acting as a scaffold for heterochromatin and many transcriptional proteins. Defects in lamina and its associated proteins cause a variety of human diseases including accelerated aging diseases such as Hutchinson-Gilford Progeria syndrome. The role of nuclear lamina in endothelial mechanotransduction, specifically how nuclear mechanics impact gene regulation under shear stress, is not fully understood. In one study, lamin A/C was silenced in bovine aortic endothelial cells to determine its role in both glucocorticoid receptor (GR) nuclear translocation and glucocorticoid response element (GRE) transcriptional activation in response to its natural ligand dexamethasone as well as fluid shear stress. Results suggest that absence of lamin A/C does not hinder passage of GR into the nucleus but nuclear lamina is important to properly regulate GRE transcription. Ongoing research continues to investigate how nuclear lamins contribute to endothelial mechanotransduction and to better understand the role of Lamin A in vascular aging and in the progression of cardiovascular diseases.
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Affiliation(s)
- Julie Y Ji
- Department of Biomedical Engineering, Indiana University Purdue University Indianapolis, Indianapolis, IN, USA.
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47
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Ankrd2 in Mechanotransduction and Oxidative Stress Response in Skeletal Muscle: New Cues for the Pathogenesis of Muscular Laminopathies. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:7318796. [PMID: 31428229 PMCID: PMC6681624 DOI: 10.1155/2019/7318796] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Revised: 05/02/2019] [Accepted: 05/19/2019] [Indexed: 12/11/2022]
Abstract
Ankrd2 (ankyrin repeats containing domain 2) or Arpp (ankyrin repeat, PEST sequence, and proline-rich region) is a member of the muscle ankyrin repeat protein family. Ankrd2 is mostly expressed in skeletal muscle, where it plays an intriguing role in the transcriptional response to stress induced by mechanical stimulation as well as by cellular reactive oxygen species. Our studies in myoblasts from Emery-Dreifuss muscular dystrophy 2, a LMNA-linked disease affecting skeletal and cardiac muscles, demonstrated that Ankrd2 is a lamin A-binding protein and that mutated lamins found in Emery-Dreifuss muscular dystrophy change the dynamics of Ankrd2 nuclear import, thus affecting oxidative stress response. In this review, besides describing the latest advances related to Ankrd2 studies, including novel discoveries on Ankrd2 isoform-specific functions, we report the main findings on the relationship of Ankrd2 with A-type lamins and discuss known and potential mechanisms involving defective Ankrd2-lamin A interplay in the pathogenesis of muscular laminopathies.
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Burridge K, Monaghan-Benson E, Graham DM. Mechanotransduction: from the cell surface to the nucleus via RhoA. Philos Trans R Soc Lond B Biol Sci 2019; 374:20180229. [PMID: 31431179 PMCID: PMC6627015 DOI: 10.1098/rstb.2018.0229] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Cells respond and adapt to their physical environments and to the mechanical forces that they experience. The translation of physical forces into biochemical signalling pathways is known as mechanotransduction. In this review, we focus on two aspects of mechanotransduction. First, we consider how forces exerted on cell adhesion molecules at the cell surface regulate the RhoA signalling pathway by controlling the activities of guanine nucleotide exchange factors (GEFs) and GTPase activating proteins (GAPs). In the second part of the review, we discuss how the nucleus contributes to mechanotransduction as a physical structure connected to the cytoskeleton. We focus on recent studies that have either severed the connections between the nucleus and the cytoskeleton, or that have entirely removed the nucleus from cells. These actions reduce the levels of active RhoA, thereby altering the mechanical properties of cells and decreasing their ability to generate tension and respond to external mechanical forces. This article is part of a discussion meeting issue ‘Forces in cancer: interdisciplinary approaches in tumour mechanobiology’.
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Affiliation(s)
- Keith Burridge
- Department of Cell Biology and Physiology, and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Elizabeth Monaghan-Benson
- Department of Cell Biology and Physiology, and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - David M Graham
- Department of Cell Biology and Physiology, and Lineberger Comprehensive Cancer Center, University of North Carolina, Chapel Hill, NC 27599, USA
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49
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Stewart RM, Rodriguez EC, King MC. Ablation of SUN2-containing LINC complexes drives cardiac hypertrophy without interstitial fibrosis. Mol Biol Cell 2019; 30:1664-1675. [PMID: 31091167 PMCID: PMC6727752 DOI: 10.1091/mbc.e18-07-0438] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The cardiomyocyte cytoskeleton, including the sarcomeric contractile apparatus, forms a cohesive network with cellular adhesions at the plasma membrane and nuclear--cytoskeletal linkages (LINC complexes) at the nuclear envelope. Human cardiomyopathies are genetically linked to the LINC complex and A-type lamins, but a full understanding of disease etiology in these patients is lacking. Here we show that SUN2-null mice display cardiac hypertrophy coincident with enhanced AKT/MAPK signaling, as has been described previously for mice lacking A-type lamins. Surprisingly, in contrast to lamin A/C-null mice, SUN2-null mice fail to show coincident fibrosis or upregulation of pathological hypertrophy markers. Thus, cardiac hypertrophy is uncoupled from profibrotic signaling in this mouse model, which we tie to a requirement for the LINC complex in productive TGFβ signaling. In the absence of SUN2, we detect elevated levels of the integral inner nuclear membrane protein MAN1, an established negative regulator of TGFβ signaling, at the nuclear envelope. We suggest that A-type lamins and SUN2 play antagonistic roles in the modulation of profibrotic signaling through opposite effects on MAN1 levels at the nuclear lamina, suggesting a new perspective on disease etiology.
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Affiliation(s)
- Rachel M Stewart
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520-8002
| | - Elisa C Rodriguez
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520-8002
| | - Megan C King
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520-8002
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50
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Cellular and Animal Models of Striated Muscle Laminopathies. Cells 2019; 8:cells8040291. [PMID: 30934932 PMCID: PMC6523539 DOI: 10.3390/cells8040291] [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: 02/06/2019] [Revised: 03/18/2019] [Accepted: 03/25/2019] [Indexed: 01/12/2023] Open
Abstract
The lamin A/C (LMNA) gene codes for nuclear intermediate filaments constitutive of the nuclear lamina. LMNA has 12 exons and alternative splicing of exon 10 results in two major isoforms—lamins A and C. Mutations found throughout the LMNA gene cause a group of diseases collectively known as laminopathies, of which the type, diversity, penetrance and severity of phenotypes can vary from one individual to the other, even between individuals carrying the same mutation. The majority of the laminopathies affect cardiac and/or skeletal muscles. The underlying molecular mechanisms contributing to such tissue-specific phenotypes caused by mutations in a ubiquitously expressed gene are not yet well elucidated. This review will explore the different phenotypes observed in established models of striated muscle laminopathies and their respective contributions to advancing our understanding of cardiac and skeletal muscle-related laminopathies. Potential future directions for developing effective treatments for patients with lamin A/C mutation-associated cardiac and/or skeletal muscle conditions will be discussed.
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