1
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Scott KL, Halfmann CT, Hoefakker AD, Purkayastha P, Wang TC, Lele TP, Roux KJ. Nucleocytoplasmic transport rates are regulated by cellular processes that modulate GTP availability. J Cell Biol 2024; 223:e202308152. [PMID: 38683248 PMCID: PMC11059771 DOI: 10.1083/jcb.202308152] [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: 09/01/2023] [Revised: 03/08/2024] [Accepted: 04/01/2024] [Indexed: 05/01/2024] Open
Abstract
Nucleocytoplasmic transport (NCT), the facilitated diffusion of cargo molecules between the nucleus and cytoplasm through nuclear pore complexes (NPCs), enables numerous fundamental eukaryotic cellular processes. Ran GTPase uses cellular energy in the direct form of GTP to create a gradient across the nuclear envelope (NE) that drives the majority of NCT. We report here that changes in GTP availability resulting from altered cellular physiology modulate the rate of NCT, as monitored using synthetic and natural cargo, and the dynamics of Ran itself. Cell migration, cell spreading, and/or modulation of the cytoskeleton or its connection to the nucleus alter GTP availability and thus rates of NCT, regulating RNA export and protein synthesis. These findings support a model in which changes in cellular physiology that alter GTP availability can regulate the rate of NCT, impacting fundamental cellular processes that extensively utilize NCT.
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Affiliation(s)
- Kelsey L. Scott
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD, USA
| | | | - Allison D. Hoefakker
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD, USA
- Basic Biomedical Sciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, USA
| | - Purboja Purkayastha
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Ting Ching Wang
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
| | - Tanmay P. Lele
- Artie McFerrin Department of Chemical Engineering, Texas A&M University, College Station, TX, USA
- Department of Biomedical Engineering, Texas A&M University, College Station, TX, USA
- Department of Translational Medical Sciences, Texas A&M University, Houston, TX, USA
| | - Kyle J. Roux
- Enabling Technologies Group, Sanford Research, Sioux Falls, SD, USA
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD, USA
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2
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Li C, Warren DT, Zhou C, De Silva S, Wilson DGS, Garcia-Maya M, Wheeler MA, Meinke P, Sawyer G, Ehler E, Wehnert M, Rao L, Zhang Q, Shanahan CM. Nesprin-2 is a novel scaffold protein for telethonin and FHL-2 in the cardiomyocyte sarcomere. J Biol Chem 2024; 300:107254. [PMID: 38569934 PMCID: PMC11078644 DOI: 10.1016/j.jbc.2024.107254] [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: 09/05/2023] [Revised: 03/11/2024] [Accepted: 03/19/2024] [Indexed: 04/05/2024] Open
Abstract
Nesprins comprise a family of multi-isomeric scaffolding proteins, forming the linker of nucleoskeleton-and-cytoskeleton complex with lamin A/C, emerin and SUN1/2 at the nuclear envelope. Mutations in nesprin-1/-2 are associated with Emery-Dreifuss muscular dystrophy (EDMD) with conduction defects and dilated cardiomyopathy (DCM). We have previously observed sarcomeric staining of nesprin-1/-2 in cardiac and skeletal muscle, but nesprin function in this compartment remains unknown. In this study, we show that specific nesprin-2 isoforms are highly expressed in cardiac muscle and localize to the Z-disc and I band of the sarcomere. Expression of GFP-tagged nesprin-2 giant spectrin repeats 52 to 53, localized to the sarcomere of neonatal rat cardiomyocytes. Yeast two-hybrid screening of a cardiac muscle cDNA library identified telethonin and four-and-half LIM domain (FHL)-2 as potential nesprin-2 binding partners. GST pull-down and immunoprecipitation confirmed the individual interactions between nesprin-2/telethonin and nesprin-2/FHL-2, and showed that nesprin-2 and telethonin binding was dependent on telethonin phosphorylation status. Importantly, the interactions between these binding partners were impaired by mutations in nesprin-2, telethonin, and FHL-2 identified in EDMD with DCM and hypertrophic cardiomyopathy patients. These data suggest that nesprin-2 is a novel sarcomeric scaffold protein that may potentially participate in the maintenance and/or regulation of sarcomeric organization and function.
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Affiliation(s)
- Chen Li
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK; Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China
| | - Derek T Warren
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK; School of Pharmacy, University of East Anglia, Norwich, UK
| | - Can Zhou
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK
| | - Shanelle De Silva
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK
| | - Darren G S Wilson
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK
| | - Mitla Garcia-Maya
- Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, London, UK
| | - Matthew A Wheeler
- Department of Cardiac Development and Remodeling, Max-Planck-Institute for Heart and Lung Research, Bad Nauheim, Germany
| | - Peter Meinke
- Friedrich-Baur-Institute at the Department of Neurology, LMU University Hospital, Munich, Germany
| | - Greta Sawyer
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK
| | - Elisabeth Ehler
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK; Randall Centre for Cell and Molecular Biophysics, School of Basic and Medical Biosciences, King's College London, London, UK
| | - Manfred Wehnert
- Institute of Human Genetics, University of Greifswald, Greifswald, Germany
| | - Li Rao
- Department of Cardiology, West China Hospital of Sichuan University, Chengdu, China
| | - Qiuping Zhang
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK.
| | - Catherine M Shanahan
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London, UK.
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3
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Sharma R, Hetzer MW. Disulfide bond in SUN2 regulates dynamic remodeling of LINC complexes at the nuclear envelope. Life Sci Alliance 2023; 6:e202302031. [PMID: 37188462 PMCID: PMC10193101 DOI: 10.26508/lsa.202302031] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 05/02/2023] [Accepted: 05/02/2023] [Indexed: 05/17/2023] Open
Abstract
The LINC complex tethers the cell nucleus to the cytoskeleton to regulate mechanical forces during cell migration, differentiation, and various diseases. The function of LINC complexes relies on the interaction between highly conserved SUN and KASH proteins that form higher-order assemblies capable of load bearing. These structural details have emerged from in vitro assembled LINC complexes; however, the principles of in vivo assembly remain obscure. Here, we report a conformation-specific SUN2 antibody as a tool to visualize LINC complex dynamics in situ. Using imaging, biochemical, and cellular methods, we find that conserved cysteines in SUN2 undergo KASH-dependent inter- and intra-molecular disulfide bond rearrangements. Disruption of the SUN2 terminal disulfide bond compromises SUN2 localization, turnover, LINC complex assembly in addition to cytoskeletal organization and cell migration. Moreover, using pharmacological and genetic perturbations, we identify components of the ER lumen as SUN2 cysteines redox state regulators. Overall, we provide evidence for SUN2 disulfide bond rearrangement as a physiologically relevant structural modification that regulates LINC complex functions.
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Affiliation(s)
- Rahul Sharma
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Martin W Hetzer
- Molecular and Cell Biology Laboratory, Salk Institute for Biological Studies, La Jolla, CA, USA
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4
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De Silva S, Fan Z, Kang B, Shanahan CM, Zhang Q. Nesprin-1: novel regulator of striated muscle nuclear positioning and mechanotransduction. Biochem Soc Trans 2023; 51:1331-1345. [PMID: 37171063 PMCID: PMC10317153 DOI: 10.1042/bst20221541] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2022] [Revised: 04/20/2023] [Accepted: 04/20/2023] [Indexed: 05/13/2023]
Abstract
Nesprins (nuclear envelope spectrin repeat proteins) are multi-isomeric scaffolding proteins. Giant nesprin-1 and -2 localise to the outer nuclear membrane, interact with SUN (Sad1p/UNC-84) domain-containing proteins at the inner nuclear membrane to form the LInker of Nucleoskeleton and Cytoskeleton (LINC) complex, which, in association with lamin A/C and emerin, mechanically couples the nucleus to the cytoskeleton. Despite ubiquitous expression of nesprin giant isoforms, pathogenic mutations in nesprin-1 and -2 are associated with tissue-specific disorders, particularly related to striated muscle such as dilated cardiomyopathy and Emery-Dreifuss muscular dystrophy. Recent evidence suggests this muscle-specificity might be attributable in part, to the small muscle specific isoform, nesprin-1α2, which has a novel role in striated muscle function. Our current understanding of muscle-specific functions of nesprin-1 and its isoforms will be summarised in this review to provide insight into potential pathological mechanisms of nesprin-related muscle disease and may inform potential targets of therapeutic modulation.
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Affiliation(s)
- Shanelle De Silva
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London SE5 9NU, U.K
| | - Zhijuan Fan
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London SE5 9NU, U.K
- Clinical Laboratory, Tianjin Third Central Hospital, Tianjin 300170, China
| | - Baoqiang Kang
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London SE5 9NU, U.K
| | - Catherine M. Shanahan
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London SE5 9NU, U.K
| | - Qiuping Zhang
- King's College London British Heart Foundation Centre of Research Excellence, School of Cardiovascular and Metabolic Medicine & Sciences, London SE5 9NU, U.K
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5
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Fonseca PAS, Suárez-Vega A, Pelayo R, Marina H, Alonso-García M, Gutiérrez-Gil B, Arranz JJ. Intergenerational impact of dietary protein restriction in dairy ewes on epigenetic marks in the perirenal fat of their suckling lambs. Sci Rep 2023; 13:4351. [PMID: 36928446 PMCID: PMC10020577 DOI: 10.1038/s41598-023-31546-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 03/14/2023] [Indexed: 03/18/2023] Open
Abstract
In sheep, nutrition during the prepubertal stage is essential for growth performance and mammary gland development. However, the potential effects of nutrient restriction in a prepuberal stage over the progeny still need to be better understood. Here, the intergenerational effect of maternal protein restriction at prepubertal age (2 months of age) on methylation patterns was evaluated in the perirenal fat of Assaf suckling lambs. In total, 17 lambs from ewes subjected to dietary protein restriction (NPR group, 44% less protein) and 17 lambs from control ewes (C group) were analyzed. These lambs were ranked based on their carcass proportion of perirenal and cavitary fat and classified into HighPCF and LowPCF groups. The perirenal tissue from 4 NPR-LowPCF, 4 NPR-HighPCF, 4 C-LowPCF, and 4 C-HighPCF lambs was subjected to whole-genome bisulfite sequencing and differentially methylated regions (DMRs) were identified. Among other relevant processes, these DMRs were mapped in genes responsible for regulating the transition of brown to white adipose tissue and nonshivering thermoregulation, which might be associated with better adaptation/survival of lambs in the perinatal stage. The current study provides important biological insights about the intergenerational effect on the methylation pattern of an NPR in replacement ewes.
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Affiliation(s)
- Pablo A S Fonseca
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana S/N, 24071, León, Spain
| | - Aroa Suárez-Vega
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana S/N, 24071, León, Spain
| | - Rocio Pelayo
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana S/N, 24071, León, Spain
| | - Hector Marina
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana S/N, 24071, León, Spain
| | - María Alonso-García
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana S/N, 24071, León, Spain
| | - Beatriz Gutiérrez-Gil
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana S/N, 24071, León, Spain
| | - Juan-José Arranz
- Departamento de Producción Animal, Facultad de Veterinaria, Universidad de León, Campus de Vegazana S/N, 24071, León, Spain.
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6
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Nadkarni AV, Heald R. Reconstitution of muscle cell microtubule organization in vitro. Cytoskeleton (Hoboken) 2022; 78:492-502. [PMID: 35666041 DOI: 10.1002/cm.21710] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 05/31/2022] [Accepted: 06/01/2022] [Indexed: 11/06/2022]
Abstract
Skeletal muscle differentiation occurs as muscle precursor cells (myoblasts) elongate and fuse to form multinucleated syncytial myotubes in which the highly-organized actomyosin sarcomeres of muscle fibers assemble. Although less well characterized, the microtubule cytoskeleton also undergoes dramatic rearrangement during myogenesis. The centrosome-nucleated microtubule array found in myoblasts is lost as the nuclear membrane acquires microtubule nucleating activity and microtubules emerge from multiple sites in the cell, eventually rearranging into a grid-like pattern in myotubes. In order to characterize perinuclear microtubule organization using a biochemically tractable system, we isolated nuclei from mouse C2C12 skeletal muscle cells during the course of differentiation and incubated them in cytoplasmic extracts prepared from eggs of the frog Xenopus laevis. Whereas centrosomes associated with myoblast nuclei gave rise to radial microtubule arrays in extracts, myotube nuclei produced a sun-like pattern with microtubules transiently nucleating from the entire nuclear envelope. Perinuclear microtubule growth was suppressed by inhibition of Aurora A kinase or by degradation of RNA, treatments that also inhibited microtubule growth from sperm centrosomes. Myotube nuclei displayed microtubule motor-based movements leading to their separation, as occurs in myotubes. This in vitro assay therefore recapitulates key features of microtubule organization and nuclear movement observed during muscle cell differentiation. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Ambika V Nadkarni
- Department of Molecular & Cell Biology, University of California, Berkeley, CA, USA
| | - Rebecca Heald
- Department of Molecular & Cell Biology, University of California, Berkeley, CA, USA
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7
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Drosophila Nesprin-1 Isoforms Differentially Contribute to Muscle Function. Cells 2021; 10:cells10113061. [PMID: 34831284 PMCID: PMC8616381 DOI: 10.3390/cells10113061] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 12/26/2022] Open
Abstract
Nesprin-1 is a large scaffold protein connecting nuclei to the actin cytoskeleton via its KASH and Calponin Homology domains, respectively. Nesprin-1 disconnection from nuclei results in altered muscle function and myonuclei mispositioning. Furthermore, Nesprin-1 mutations are associated with muscular pathologies such as Emery Dreifuss muscular dystrophy and arthrogryposis. Nesprin-1 was thus proposed to mainly contribute to muscle function by controlling nuclei position. However, Nesprin-1′s localisation at sarcomere’s Z-discs, its involvement in organelles’ subcellular localization, as well as the description of numerous isoforms presenting different combinations of Calponin Homology (CH) and KASH domains, suggest that the contribution of Nesprin-1 to muscle functions is more complex. Here, we investigate the roles of Nesprin-1/Msp300 isoforms in muscle function and subcellular organisation using Drosophila larvae as a model. Subsets of Msp300 isoform were down-regulated by muscle-specific RNAi expression and muscle global function and morphology were assessed. We show that nuclei anchoring in mature muscle and global muscle function are disconnected functions associated with different Msp300 isoforms. Our work further uncovers a new and unsuspected role of Msp300 in myofibril registration and nuclei peripheral displacement supported by Msp300 CH containing isoforms, a function performed by Desmin in mammals.
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8
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Iyer SR, Folker ES, Lovering RM. The Nucleoskeleton: Crossroad of Mechanotransduction in Skeletal Muscle. Front Physiol 2021; 12:724010. [PMID: 34721058 PMCID: PMC8554227 DOI: 10.3389/fphys.2021.724010] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 09/24/2021] [Indexed: 11/13/2022] Open
Abstract
Intermediate filaments (IFs) are a primary structural component of the cytoskeleton extending throughout the muscle cell (myofiber). Mechanotransduction, the process by which mechanical force is translated into a biochemical signal to activate downstream cellular responses, is crucial to myofiber function. Mechanical forces also act on the nuclear cytoskeleton, which is integrated with the myofiber cytoskeleton by the linker of the nucleoskeleton and cytoskeleton (LINC) complexes. Thus, the nucleus serves as the endpoint for the transmission of force through the cell. The nuclear lamina, a dense meshwork of lamin IFs between the nuclear envelope and underlying chromatin, plays a crucial role in responding to mechanical input; myofibers constantly respond to mechanical perturbation via signaling pathways by activation of specific genes. The nucleus is the largest organelle in cells and a master regulator of cell homeostasis, thus an understanding of how it responds to its mechanical environment is of great interest. The importance of the cell nucleus is magnified in skeletal muscle cells due to their syncytial nature and the extreme mechanical environment that muscle contraction creates. In this review, we summarize the bidirectional link between the organization of the nucleoskeleton and the contractile features of skeletal muscle as they relate to muscle function.
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Affiliation(s)
- Shama R Iyer
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD, United States
| | - Eric S Folker
- Department of Biology, Boston College, Chestnut Hill, MA, United States
| | - Richard M Lovering
- Department of Orthopaedics, University of Maryland School of Medicine, Baltimore, MD, United States.,Department of Physiology, University of Maryland School of Medicine, Baltimore, MD, United States
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9
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Becker R, Vergarajauregui S, Billing F, Sharkova M, Lippolis E, Mamchaoui K, Ferrazzi F, Engel FB. Myogenin controls via AKAP6 non-centrosomal microtubule-organizing center formation at the nuclear envelope. eLife 2021; 10:65672. [PMID: 34605406 PMCID: PMC8523159 DOI: 10.7554/elife.65672] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Accepted: 10/01/2021] [Indexed: 12/22/2022] Open
Abstract
Non-centrosomal microtubule-organizing centers (MTOCs) are pivotal for the function of multiple cell types, but the processes initiating their formation are unknown. Here, we find that the transcription factor myogenin is required in murine myoblasts for the localization of MTOC proteins to the nuclear envelope. Moreover, myogenin is sufficient in fibroblasts for nuclear envelope MTOC (NE-MTOC) formation and centrosome attenuation. Bioinformatics combined with loss- and gain-of-function experiments identified induction of AKAP6 expression as one central mechanism for myogenin-mediated NE-MTOC formation. Promoter studies indicate that myogenin preferentially induces the transcription of muscle- and NE-MTOC-specific isoforms of Akap6 and Syne1, which encodes nesprin-1α, the NE-MTOC anchor protein in muscle cells. Overexpression of AKAP6β and nesprin-1α was sufficient to recruit endogenous MTOC proteins to the nuclear envelope of myoblasts in the absence of myogenin. Taken together, our results illuminate how mammals transcriptionally control the switch from a centrosomal MTOC to an NE-MTOC and identify AKAP6 as a novel NE-MTOC component in muscle cells.
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Affiliation(s)
- Robert Becker
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Silvia Vergarajauregui
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Florian Billing
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Maria Sharkova
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Eleonora Lippolis
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Kamel Mamchaoui
- Sorbonne Universités UPMC Université Paris 06, INSERM U974, CNRS FRE3617, Center for Research in Myology, GH Pitié Salpêtrière, 47 Boulevard de l'Hôpital, Paris, France
| | - Fulvia Ferrazzi
- Institute of Human Genetics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.,Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Felix B Engel
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.,Muscle Research Center Erlangen (MURCE), Erlangen, Germany
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10
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Culturing Keratinocytes on Biomimetic Substrates Facilitates Improved Epidermal Assembly In Vitro. Cells 2021; 10:cells10051177. [PMID: 34066027 PMCID: PMC8151809 DOI: 10.3390/cells10051177] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Revised: 04/29/2021] [Accepted: 05/09/2021] [Indexed: 12/18/2022] Open
Abstract
Mechanotransduction is defined as the ability of cells to sense mechanical stimuli from their surroundings and translate them into biochemical signals. Epidermal keratinocytes respond to mechanical cues by altering their proliferation, migration, and differentiation. In vitro cell culture, however, utilises tissue culture plastic, which is significantly stiffer than the in vivo environment. Current epidermal models fail to consider the effects of culturing keratinocytes on plastic prior to setting up three-dimensional cultures, so the impact of this non-physiological exposure on epidermal assembly is largely overlooked. In this study, primary keratinocytes cultured on plastic were compared with those grown on 4, 8, and 50 kPa stiff biomimetic hydrogels that have similar mechanical properties to skin. Our data show that keratinocytes cultured on biomimetic hydrogels exhibited major changes in cellular architecture, cell density, nuclear biomechanics, and mechanoprotein expression, such as specific Linker of Nucleoskeleton and Cytoskeleton (LINC) complex constituents. Mechanical conditioning of keratinocytes on 50 kPa biomimetic hydrogels improved the thickness and organisation of 3D epidermal models. In summary, the current study demonstrates that the effects of extracellular mechanics on keratinocyte cell biology are significant and therefore should be harnessed in skin research to ensure the successful production of physiologically relevant skin models.
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11
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Sferra A, Fortugno P, Motta M, Aiello C, Petrini S, Ciolfi A, Cipressa F, Moroni I, Leuzzi V, Pieroni L, Marini F, Boespflug Tanguy O, Eymard-Pierre E, Danti FR, Compagnucci C, Zambruno G, Brusco A, Santorelli FM, Chiapparini L, Francalanci P, Loizzo AL, Tartaglia M, Cestra G, Bertini E. Biallelic mutations in RNF220 cause laminopathies featuring leukodystrophy, ataxia and deafness. Brain 2021; 144:3020-3035. [PMID: 33964137 DOI: 10.1093/brain/awab185] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 04/14/2021] [Accepted: 04/29/2021] [Indexed: 11/13/2022] Open
Abstract
Leukodystrophies are a heterogeneous group of rare inherited disorders that involve preferentially the white matter of the central nervous system (CNS). These conditions are characterized by a primary glial cell and myelin sheath pathology of variable etiology, which causes secondary axonal degeneration, generally emerging with disease progression. Whole exome sequencing performed in 5 large consanguineous nuclear families allowed to identify homozygosity for two recurrent missense variants affecting highly conserved residues of RNF220 as the causative event underlying a novel form of leukodystrophy with ataxia and sensorineural deafness. We report on two homozygous missense variants (p.R363Q and p.R365Q) in the ubiquitin E3 ligase RNF220 as the cause underlying a novel form of leukodystrophy with ataxia and sensorineural deafness having fibrotic cardiomyopathy and hepatopathy as associated features, in seven consanguineous families. Mass spectrometry analysis identified lamin B1 as RNF220 binding protein and co-immunoprecipitation experiments demonstrated reduced binding of both RNF220 mutants to lamin B1. We demonstrate that RNF220 silencing in Drosophila melanogaster specifically affects proper localization of lamin Dm0, the fly lamin B1 orthologue, promotes its aggregation, and causes a neurodegenerative phenotype, strongly supporting the functional link between RNF220 and lamin B1. Finally, we demonstrate that RNF220 plays a crucial role in the maintenance of nuclear morphology: mutations primary skin fibroblasts determine nuclear abnormalities such as blebs, herniations and invaginations, which are typically observed in cells of patients affected by laminopathies. Overall, our data identify RNF220 as a gene implicated in leukodystrophy with ataxia and sensorineural deafness, and document a critical role of RNF220 in the regulation of nuclear lamina. Our findings provide further evidence on the direct link between nuclear lamina dysfunction and neurodegeneration.
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Affiliation(s)
- Antonella Sferra
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, 00146 Rome, Italy
| | - Paola Fortugno
- Department of Life, Health and Environmental Sciences University of L'Aquila, 00167 Rome, Italy.,Human Functional Genomics, IRCCS San Raffaele Pisana, 00166 Rome, Italy
| | - Marialetizia Motta
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, 00146 Rome, Italy
| | - Chiara Aiello
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, 00146 Rome, Italy
| | - Stefania Petrini
- Confocal Microscopy Core Facility, Research Laboratories, Ospedale Pediatrico Bambino Gesù, 00146 Rome, Italy
| | - Andrea Ciolfi
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, 00146 Rome, Italy
| | - Francesca Cipressa
- University of Rome "Sapienza", Department of Biology and Biotechnology, 00185 Rome, Italy
| | - Isabella Moroni
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy
| | - Vincenzo Leuzzi
- Department of Human Neuroscience, Unit of Child Neurology and Psychiatry, Sapienza University, 00185 Rome, Italy
| | | | - Federica Marini
- Institute of Biochemistry and Clinical Biochemistry, Università Cattolica del Sacro Cuore, 00168 Rome, Italy.,Department of Laboratory Diagnostic and Infectious Diseases, Fondazione Policlinico Universitario Agostino Gemelli IRCCS, 00168 Rome, Italy
| | - Odile Boespflug Tanguy
- Service de Neurologie Pédiatrique, Centre de reference leucodystrophies et leucoencephalopathies de cause rare (LEUKOFRANCE), APHP Hopital Robert-Debré, 75019 Paris, France.,Université de Paris, NeuroDiderot, UMR 1141 INSERM 75651 Paris, France
| | - Eleonore Eymard-Pierre
- Service de Cytogénétique Médicale CHU de Clermont Ferrand, Hopital ESTAING 63003 CLERMONT FERRAND, France
| | - Federica Rachele Danti
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy
| | - Claudia Compagnucci
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, 00146 Rome, Italy
| | - Giovanna Zambruno
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, 00146 Rome, Italy
| | - Alfredo Brusco
- Department of Medical Sciences, University of Torino, 10124 Turin, Italy
| | | | - Luisa Chiapparini
- Neuroradiology Department, Fondazione IRCCS Istituto Neurologico Carlo Besta, 20133 Milan, Italy
| | - Paola Francalanci
- Department of Laboratories, Pathology Unit, IRCCS Bambino Gesù Children's Hospital, 00165 Rome, Italy
| | - Anna Livia Loizzo
- DIDASCO Società Cooperativa Sociale- Centro di riabilitazione, 00185 Rome, Italy
| | - Marco Tartaglia
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, 00146 Rome, Italy
| | - Gianluca Cestra
- University of Rome "Sapienza", Department of Biology and Biotechnology, 00185 Rome, Italy.,Santa Lucia IRCCS Foundation, 00179 Rome, Italy.,Institute of Biochemistry and Clinical Biochemistry, Università Cattolica del Sacro Cuore, 00168 Rome, Italy.,Institute of Molecular Biology and Pathology (IBPM), National Research Council (CNR) 00185 Rome, Italy
| | - Enrico Bertini
- Genetics and Rare Diseases Research Division, Bambino Gesù Children's Hospital, IRCCS, 00146 Rome, Italy
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12
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Déjardin T, Carollo PS, Sipieter F, Davidson PM, Seiler C, Cuvelier D, Cadot B, Sykes C, Gomes ER, Borghi N. Nesprins are mechanotransducers that discriminate epithelial-mesenchymal transition programs. J Cell Biol 2021; 219:152020. [PMID: 32790861 PMCID: PMC7659719 DOI: 10.1083/jcb.201908036] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Revised: 04/23/2020] [Accepted: 07/21/2020] [Indexed: 01/15/2023] Open
Abstract
LINC complexes are transmembrane protein assemblies that physically connect the nucleoskeleton and cytoskeleton through the nuclear envelope. Dysfunctions of LINC complexes are associated with pathologies such as cancer and muscular disorders. The mechanical roles of LINC complexes are poorly understood. To address this, we used genetically encoded FRET biosensors of molecular tension in a nesprin protein of the LINC complex of fibroblastic and epithelial cells in culture. We exposed cells to mechanical, genetic, and pharmacological perturbations, mimicking a range of physiological and pathological situations. We show that nesprin experiences tension generated by the cytoskeleton and acts as a mechanical sensor of cell packing. Moreover, nesprin discriminates between inductions of partial and complete epithelial–mesenchymal transitions. We identify the implicated mechanisms, which involve α-catenin capture at the nuclear envelope by nesprin upon its relaxation, thereby regulating β-catenin transcription. Our data thus implicate LINC complex proteins as mechanotransducers that fine-tune β-catenin signaling in a manner dependent on the epithelial–mesenchymal transition program.
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Affiliation(s)
- Théophile Déjardin
- Université de Paris, Centre National de la Recherche Scientifique, Institut Jacques Monod, Paris, France
| | - Pietro Salvatore Carollo
- Université de Paris, Centre National de la Recherche Scientifique, Institut Jacques Monod, Paris, France
| | - François Sipieter
- Université de Paris, Centre National de la Recherche Scientifique, Institut Jacques Monod, Paris, France
| | - Patricia M Davidson
- Laboratoire Physico-Chimie Curie, Institut Curie, Centre National de la Recherche Scientifique Unité Mixte de Recherche 168, Sorbonne Universités, Université Paris Sciences et Lettres, Paris, France
| | - Cynthia Seiler
- Université de Paris, Centre National de la Recherche Scientifique, Institut Jacques Monod, Paris, France
| | - Damien Cuvelier
- Institut Curie and Institut Pierre Gilles de Gennes, Université Paris Sciences et Lettres, Centre National de la Recherche Scientifique Unité Mixte de Rercherche 144, Paris, France
| | - Bruno Cadot
- Center for Research in Myology, Institut National de la Santé et de la Recherche Médicale Unité Mixte de Recherche 974, Sorbonne Universités, Paris, France
| | - Cecile Sykes
- Laboratoire Physico-Chimie Curie, Institut Curie, Centre National de la Recherche Scientifique Unité Mixte de Recherche 168, Sorbonne Universités, Université Paris Sciences et Lettres, Paris, France
| | - Edgar R Gomes
- Center for Research in Myology, Institut National de la Santé et de la Recherche Médicale Unité Mixte de Recherche 974, Sorbonne Universités, Paris, France.,Instituto de Medecina Molecular, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.,Instituto de Histologia e Biologia do Desenvolvimento, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | - Nicolas Borghi
- Université de Paris, Centre National de la Recherche Scientifique, Institut Jacques Monod, Paris, France
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13
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Jabre S, Hleihel W, Coirault C. Nuclear Mechanotransduction in Skeletal Muscle. Cells 2021; 10:cells10020318. [PMID: 33557157 PMCID: PMC7913907 DOI: 10.3390/cells10020318] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 12/11/2022] Open
Abstract
Skeletal muscle is composed of multinucleated, mature muscle cells (myofibers) responsible for contraction, and a resident pool of mononucleated muscle cell precursors (MCPs), that are maintained in a quiescent state in homeostatic conditions. Skeletal muscle is remarkable in its ability to adapt to mechanical constraints, a property referred as muscle plasticity and mediated by both MCPs and myofibers. An emerging body of literature supports the notion that muscle plasticity is critically dependent upon nuclear mechanotransduction, which is transduction of exterior physical forces into the nucleus to generate a biological response. Mechanical loading induces nuclear deformation, changes in the nuclear lamina organization, chromatin condensation state, and cell signaling, which ultimately impacts myogenic cell fate decisions. This review summarizes contemporary insights into the mechanisms underlying nuclear force transmission in MCPs and myofibers. We discuss how the cytoskeleton and nuclear reorganizations during myogenic differentiation may affect force transmission and nuclear mechanotransduction. We also discuss how to apply these findings in the context of muscular disorders. Finally, we highlight current gaps in knowledge and opportunities for further research in the field.
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Affiliation(s)
- Saline Jabre
- Sorbonne Université, INSERM UMRS-974 and Institut de Myologie, 75013 Paris, France;
- Department of Biology, Faculty of Arts and Sciences, Holy Spirit University of Kasik (USEK), Jounieh 446, Lebanon;
| | - Walid Hleihel
- Department of Biology, Faculty of Arts and Sciences, Holy Spirit University of Kasik (USEK), Jounieh 446, Lebanon;
- Department of Basic Health Sciences, Faculty of Medicine, Holy Spirit University of Kaslik (USEK), Jounieh 446, Lebanon
| | - Catherine Coirault
- Sorbonne Université, INSERM UMRS-974 and Institut de Myologie, 75013 Paris, France;
- Correspondence:
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14
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Vergarajauregui S, Becker R, Steffen U, Sharkova M, Esser T, Petzold J, Billing F, Kapiloff MS, Schett G, Thievessen I, Engel FB. AKAP6 orchestrates the nuclear envelope microtubule-organizing center by linking golgi and nucleus via AKAP9. eLife 2020; 9:61669. [PMID: 33295871 PMCID: PMC7725499 DOI: 10.7554/elife.61669] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Accepted: 12/03/2020] [Indexed: 12/31/2022] Open
Abstract
The switch from centrosomal microtubule-organizing centers (MTOCs) to non-centrosomal MTOCs during differentiation is poorly understood. Here, we identify AKAP6 as key component of the nuclear envelope MTOC. In rat cardiomyocytes, AKAP6 anchors centrosomal proteins to the nuclear envelope through its spectrin repeats, acting as an adaptor between nesprin-1α and Pcnt or AKAP9. In addition, AKAP6 and AKAP9 form a protein platform tethering the Golgi to the nucleus. Both Golgi and nuclear envelope exhibit MTOC activity utilizing either AKAP9, or Pcnt-AKAP9, respectively. AKAP6 is also required for formation and activity of the nuclear envelope MTOC in human osteoclasts. Moreover, ectopic expression of AKAP6 in epithelial cells is sufficient to recruit endogenous centrosomal proteins. Finally, AKAP6 is required for cardiomyocyte hypertrophy and osteoclast bone resorption activity. Collectively, we decipher the MTOC at the nuclear envelope as a bi-layered structure generating two pools of microtubules with AKAP6 as a key organizer.
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Affiliation(s)
- Silvia Vergarajauregui
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Robert Becker
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Ulrike Steffen
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany
| | - Maria Sharkova
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Tilman Esser
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Jana Petzold
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Florian Billing
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Michael S Kapiloff
- Departments of Ophthalmology and Medicine, Stanford Cardiovascular Institute, Stanford University, Palo Alto, United States
| | - George Schett
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany
| | - Ingo Thievessen
- Department of Physics, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany.,Muscle Research Center Erlangen (MURCE), Erlangen, Germany
| | - Felix B Engel
- Experimental Renal and Cardiovascular Research, Department of Nephropathology, Institute of Pathology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany.,Muscle Research Center Erlangen (MURCE), Erlangen, Germany
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15
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Muscle cell differentiation and development pathway defects in Emery-Dreifuss muscular dystrophy. Neuromuscul Disord 2020; 30:443-456. [DOI: 10.1016/j.nmd.2020.04.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 03/20/2020] [Accepted: 04/15/2020] [Indexed: 12/12/2022]
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16
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Davidson PM, Battistella A, Déjardin T, Betz T, Plastino J, Borghi N, Cadot B, Sykes C. Nesprin-2 accumulates at the front of the nucleus during confined cell migration. EMBO Rep 2020; 21:e49910. [PMID: 32419336 DOI: 10.15252/embr.201949910] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 04/15/2020] [Accepted: 04/21/2020] [Indexed: 12/12/2022] Open
Abstract
The mechanisms by which cells exert forces on their nuclei to migrate through openings smaller than the nuclear diameter remain unclear. We use CRISPR/Cas9 to fluorescently label nesprin-2 giant, which links the cytoskeleton to the nuclear interior. We demonstrate that nesprin-2 accumulates at the front of the nucleus during nuclear deformation through narrow constrictions, independently of the nuclear lamina. We find that nesprins are mobile at time scales similar to the accumulation. Using artificial constructs, we show that the actin-binding domain of nesprin-2 is necessary and sufficient for this accumulation. Actin filaments are organized in a barrel structure around the nucleus in the direction of movement. Using two-photon ablation and cytoskeleton-inhibiting drugs, we demonstrate an actomyosin-dependent pulling force on the nucleus from the front of the cell. The elastic recoil upon ablation is dampened when nesprins are reduced at the nuclear envelope. We thus show that actin redistributes nesprin-2 giant toward the front of the nucleus and contributes to pulling the nucleus through narrow constrictions, in concert with myosin.
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Affiliation(s)
- Patricia M Davidson
- Laboratoire Physico-Chimie Curie, Institut Curie, CNRS UMR168, Sorbonne Université, PSL, Paris, France.,Center for Research in Myology, INSERM UMR974, Sorbonne Université, Paris, France
| | - Aude Battistella
- Laboratoire Physico-Chimie Curie, Institut Curie, CNRS UMR168, Sorbonne Université, PSL, Paris, France
| | - Théophile Déjardin
- Laboratoire Physico-Chimie Curie, Institut Curie, CNRS UMR168, Sorbonne Université, PSL, Paris, France.,Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Paris, France
| | - Timo Betz
- Institute of Cell Biology, ZMBE, Münster, Germany
| | - Julie Plastino
- Laboratoire Physico-Chimie Curie, Institut Curie, CNRS UMR168, Sorbonne Université, PSL, Paris, France
| | - Nicolas Borghi
- Institut Jacques Monod, CNRS, UMR 7592, Université Paris Diderot, Paris, France
| | - Bruno Cadot
- Center for Research in Myology, INSERM UMR974, Sorbonne Université, Paris, France
| | - Cécile Sykes
- Laboratoire Physico-Chimie Curie, Institut Curie, CNRS UMR168, Sorbonne Université, PSL, Paris, France
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17
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Porter L, Minaisah RM, Ahmed S, Ali S, Norton R, Zhang Q, Ferraro E, Molenaar C, Holt M, Cox S, Fountain S, Shanahan C, Warren D. SUN1/2 Are Essential for RhoA/ROCK-Regulated Actomyosin Activity in Isolated Vascular Smooth Muscle Cells. Cells 2020; 9:cells9010132. [PMID: 31935926 PMCID: PMC7017107 DOI: 10.3390/cells9010132] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Revised: 12/20/2019] [Accepted: 12/20/2019] [Indexed: 12/15/2022] Open
Abstract
Vascular smooth muscle cells (VSMCs) are the predominant cell type in the blood vessel wall. Changes in VSMC actomyosin activity and morphology are prevalent in cardiovascular disease. The actin cytoskeleton actively defines cellular shape and the LInker of Nucleoskeleton and Cytoskeleton (LINC) complex, comprised of nesprin and the Sad1p, UNC-84 (SUN)-domain family members SUN1/2, has emerged as a key regulator of actin cytoskeletal organisation. Although SUN1 and SUN2 function is partially redundant, they possess specific functions and LINC complex composition is tailored for cell-type-specific functions. We investigated the importance of SUN1 and SUN2 in regulating actomyosin activity and cell morphology in VSMCs. We demonstrate that siRNA-mediated depletion of either SUN1 or SUN2 altered VSMC spreading and impaired actomyosin activity and RhoA activity. Importantly, these findings were recapitulated using aortic VSMCs isolated from wild-type and SUN2 knockout (SUN2 KO) mice. Inhibition of actomyosin activity, using the rho-associated, coiled-coil-containing protein kinase1/2 (ROCK1/2) inhibitor Y27632 or blebbistatin, reduced SUN2 mobility in the nuclear envelope and decreased the association between SUN2 and lamin A, confirming that SUN2 dynamics and interactions are influenced by actomyosin activity. We propose that the LINC complex exists in a mechanical feedback circuit with RhoA to regulate VSMC actomyosin activity and morphology.
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Affiliation(s)
- Lauren Porter
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
| | - Rose-Marie Minaisah
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
| | - Sultan Ahmed
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Seema Ali
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Rosemary Norton
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Qiuping Zhang
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
| | - Elisa Ferraro
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
| | - Chris Molenaar
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
| | - Mark Holt
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, King’s College London, London SE1 1YR, UK
| | - Susan Cox
- Randall Division of Cell and Molecular Biophysics, New Hunt’s House, King’s College London, London SE1 1YR, UK
| | - Samuel Fountain
- School of Biological Sciences, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
| | - Catherine Shanahan
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
| | - Derek Warren
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King’s College London, London SE5 9NU, UK
- School of Pharmacy, University of East Anglia, Norwich Research Park, Norwich NR4 7TJ, UK
- Correspondence:
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18
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Nesprin-1-alpha2 associates with kinesin at myotube outer nuclear membranes, but is restricted to neuromuscular junction nuclei in adult muscle. Sci Rep 2019; 9:14202. [PMID: 31578382 PMCID: PMC6775114 DOI: 10.1038/s41598-019-50728-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 09/03/2019] [Indexed: 12/16/2022] Open
Abstract
Nesprins, nuclear envelope spectrin-repeat proteins encoded by the SYNE1 and SYNE2 genes, are involved in localization of nuclei. The short isoform, nesprin-1-alpha2, is required for relocation of the microtubule organizer function from centromeres to the nuclear rim during myogenesis. Using specific antibodies, we now show that both nesprin-1-alpha2 and nesprin-1-giant co-localize with kinesin at the junctions of concatenated nuclei and at the outer poles of nuclear chains in human skeletal myotubes. In adult muscle, nesprin-1-alpha2 was found, together with kinesin, only on nuclei associated with neuromuscular junctions, whereas all adult cardiomyocyte nuclei expressed nesprin-1-alpha2. In a proteomics study, kinesin heavy and light chains were the only significant proteins in myotube extracts pulled down by nesprin-1-alpha2, but not by a mutant lacking the highly-conserved STAR domain (18 amino-acids, including the LEWD motif). The results support a function for nesprin-1-alpha2 in the specific localization of skeletal muscle nuclei mediated by kinesins and suggest that its primary role is at the outer nuclear membrane.
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19
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Sola-Carvajal A, Revêchon G, Helgadottir HT, Whisenant D, Hagblom R, Döhla J, Katajisto P, Brodin D, Fagerström-Billai F, Viceconte N, Eriksson M. Accumulation of Progerin Affects the Symmetry of Cell Division and Is Associated with Impaired Wnt Signaling and the Mislocalization of Nuclear Envelope Proteins. J Invest Dermatol 2019; 139:2272-2280.e12. [PMID: 31128203 DOI: 10.1016/j.jid.2019.05.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2018] [Revised: 05/02/2019] [Accepted: 05/08/2019] [Indexed: 12/17/2022]
Abstract
Hutchinson-Gilford progeria syndrome (HGPS) is the result of a defective form of the lamin A protein called progerin. While progerin is known to disrupt the properties of the nuclear lamina, the underlying mechanisms responsible for the pathophysiology of HGPS remain less clear. Previous studies in our laboratory have shown that progerin expression in murine epidermal basal cells results in impaired stratification and halted development of the skin. Stratification and differentiation of the epidermis is regulated by asymmetric stem cell division. Here, we show that expression of progerin impairs the ability of stem cells to maintain tissue homeostasis as a result of altered cell division. Quantification of basal skin cells showed an increase in symmetric cell division that correlated with progerin accumulation in HGPS mice. Investigation of the mechanisms underlying this phenomenon revealed a putative role of Wnt/β-catenin signaling. Further analysis suggested an alteration in the nuclear translocation of β-catenin involving the inner and outer nuclear membrane proteins, emerin and nesprin-2. Taken together, our results suggest a direct involvement of progerin in the transmission of Wnt signaling and normal stem cell division. These insights into the molecular mechanisms of progerin may help develop new treatment strategies for HGPS.
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Affiliation(s)
- Agustín Sola-Carvajal
- Department of Biosciences and Nutrition, Center for Innovative Medicine, Karolinska Institutet, Huddinge, Sweden.
| | - Gwladys Revêchon
- Department of Biosciences and Nutrition, Center for Innovative Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Hafdis T Helgadottir
- Department of Biosciences and Nutrition, Center for Innovative Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Daniel Whisenant
- Department of Biosciences and Nutrition, Center for Innovative Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Robin Hagblom
- Department of Biosciences and Nutrition, Center for Innovative Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Julia Döhla
- Department of Biosciences and Nutrition, Center for Innovative Medicine, Karolinska Institutet, Huddinge, Sweden; Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - Pekka Katajisto
- Department of Biosciences and Nutrition, Center for Innovative Medicine, Karolinska Institutet, Huddinge, Sweden; Institute of Biotechnology, University of Helsinki, Helsinki, Finland
| | - David Brodin
- Bioinformatics and Expression Core Facility, Karolinska Institutet, Huddinge, Sweden
| | | | - Nikenza Viceconte
- Department of Biosciences and Nutrition, Center for Innovative Medicine, Karolinska Institutet, Huddinge, Sweden
| | - Maria Eriksson
- Department of Biosciences and Nutrition, Center for Innovative Medicine, Karolinska Institutet, Huddinge, Sweden.
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20
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Brull A, Morales Rodriguez B, Bonne G, Muchir A, Bertrand AT. The Pathogenesis and Therapies of Striated Muscle Laminopathies. Front Physiol 2018; 9:1533. [PMID: 30425656 PMCID: PMC6218675 DOI: 10.3389/fphys.2018.01533] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 10/11/2018] [Indexed: 01/04/2023] Open
Abstract
Emery-Dreifuss muscular dystrophy (EDMD) is a genetic condition characterized by early contractures, skeletal muscle weakness, and cardiomyopathy. During the last 20 years, various genetic approaches led to the identification of causal genes of EDMD and related disorders, all encoding nuclear envelope proteins. By their respective localization either at the inner nuclear membrane or the outer nuclear membrane, these proteins interact with each other and establish a connection between the nucleus and the cytoskeleton. Beside this physical link, these proteins are also involved in mechanotransduction, responding to environmental cues, such as increased tension of the cytoskeleton, by the activation or repression of specific sets of genes. This ability of cells to adapt to environmental conditions is altered in EDMD. Increased knowledge on the pathophysiology of EDMD has led to the development of drug or gene therapies that have been tested on mouse models. This review proposed an overview of the functions played by the different proteins involved in EDMD and related disorders and the current therapeutic approaches tested so far.
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Affiliation(s)
- Astrid Brull
- Sorbonne Université, INSERM, Institut de Myologie, Center of Research in Myology, UMRS 974, Paris, France
| | - Blanca Morales Rodriguez
- Sorbonne Université, INSERM, Institut de Myologie, Center of Research in Myology, UMRS 974, Paris, France.,Sanofi R&D, Chilly Mazarin, France
| | - Gisèle Bonne
- Sorbonne Université, INSERM, Institut de Myologie, Center of Research in Myology, UMRS 974, Paris, France
| | - Antoine Muchir
- Sorbonne Université, INSERM, Institut de Myologie, Center of Research in Myology, UMRS 974, Paris, France
| | - Anne T Bertrand
- Sorbonne Université, INSERM, Institut de Myologie, Center of Research in Myology, UMRS 974, Paris, France
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21
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Janin A, Gache V. Nesprins and Lamins in Health and Diseases of Cardiac and Skeletal Muscles. Front Physiol 2018; 9:1277. [PMID: 30245638 PMCID: PMC6137955 DOI: 10.3389/fphys.2018.01277] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 08/22/2018] [Indexed: 12/26/2022] Open
Abstract
Since the discovery of the inner nuclear transmembrane protein emerin in the early 1990s, nuclear envelope (NE) components and related involvement in nuclei integrity and functionality have been highly investigated. The NE is composed of two distinct lipid bilayers described as the inner (INM) and outer (ONM) nuclear membrane. NE proteins can be specifically “integrated” in the INM (such as emerin and SUN proteins) or in the ONM such as nesprins. Additionally, flanked to the INM, the nuclear lamina, a proteinaceous meshwork mainly composed of lamins A and C completes NE composition. This network of proteins physically interplays to guarantee NE integrity and most importantly, shape the bridge between cytoplasmic cytoskeletons networks (such as microtubules and actin) and the genome, through the anchorage to the heterochromatin. The essential network driving the connection of nucleoskeleton with cytoskeleton takes place in the perinuclear space (the space between ONM and INM) with the contribution of the LINC complex (for Linker of Nucleoskeleton to Cytoskeleton), hosting KASH and SUN proteins interactions. This close interplay between compartments has been related to diverse functions from nuclear integrity, activity and positioning through mechanotransduction pathways. At the same time, mutations in NE components genes coding for proteins such as lamins or nesprins, had been associated with a wide range of congenital diseases including cardiac and muscular diseases. Although most of these NE associated proteins are ubiquitously expressed, a large number of tissue-specific disorders have been associated with diverse pathogenic mutations. Thus, diagnosis and molecular explanation of this group of diseases, commonly called “nuclear envelopathies,” is currently challenging. This review aims, first, to give a better understanding of diverse functions of the LINC complex components, from the point of view of lamins and nesprins. Second, to summarize human congenital diseases with a special focus on muscle and heart abnormalities, caused by mutations in genes coding for these two types of NE associated proteins.
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Affiliation(s)
- Alexandre Janin
- CNRS UMR5310, INSERM U1217, Institut NeuroMyoGène, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France.,Laboratoire de Cardiogénétique Moléculaire, Centre de Biologie et Pathologie Est, Hospices Civils de Lyon, Bron, France
| | - Vincent Gache
- CNRS UMR5310, INSERM U1217, Institut NeuroMyoGène, Université Claude Bernard Lyon 1, Université de Lyon, Lyon, France
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22
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LINC complex-Lis1 interplay controls MT1-MMP matrix digest-on-demand response for confined tumor cell migration. Nat Commun 2018; 9:2443. [PMID: 29934494 PMCID: PMC6015082 DOI: 10.1038/s41467-018-04865-7] [Citation(s) in RCA: 77] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/09/2018] [Indexed: 12/13/2022] Open
Abstract
Cancer cells’ ability to migrate through constricting pores in the tissue matrix is limited by nuclear stiffness. MT1-MMP contributes to metastasis by widening matrix pores, facilitating confined migration. Here, we show that modulation of matrix pore size or of lamin A expression known to modulate nuclear stiffness directly impinges on levels of MT1-MMP-mediated pericellular collagenolysis by cancer cells. A component of this adaptive response is the centrosome-centered distribution of MT1-MMP intracellular storage compartments ahead of the nucleus. We further show that this response, including invadopodia formation in association with confining matrix fibrils, requires an intact connection between the nucleus and the centrosome via the linker of nucleoskeleton and cytoskeleton (LINC) complex protein nesprin-2 and dynein adaptor Lis1. Our results uncover a digest-on-demand strategy for nuclear translocation through constricted spaces whereby confined migration triggers polarization of MT1-MMP storage compartments and matrix proteolysis in front of the nucleus depending on nucleus-microtubule linkage. The ability of cancer cells to migrate through small, constricted areas is limited by nuclear stiffness. Here the authors show that in turn nuclear stiffness stimulates the delivery of enzymes important for the degradation of the extracellular matrix and the formation of invadopodia in association with fibers thus opposing nuclear movement.
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23
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Linker of nucleoskeleton and cytoskeleton complex proteins in cardiomyopathy. Biophys Rev 2018; 10:1033-1051. [PMID: 29869195 PMCID: PMC6082319 DOI: 10.1007/s12551-018-0431-6] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 05/24/2018] [Indexed: 12/21/2022] Open
Abstract
The linker of nucleoskeleton and cytoskeleton (LINC) complex couples the nuclear lamina to the cytoskeleton. The LINC complex and its associated proteins play diverse roles in cells, ranging from genome organization, nuclear morphology, gene expression, to mechanical stability. The importance of a functional LINC complex is highlighted by the large number of mutations in genes encoding LINC complex proteins that lead to skeletal and cardiac myopathies. In this review, the structure, function, and interactions between components of the LINC complex will be described. Mutations that are known to cause cardiomyopathy in patients will be discussed alongside their respective mouse models. Furthermore, future challenges for the field and emerging technologies to investigate LINC complex function will be discussed.
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24
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Yang Y, Qu R, Fan T, Zhu X, Feng Y, Yang Y, Deng T, Peng Y, Huang W, Ouyang J, Dai J. Cross-talk between microtubules and the linker of nucleoskeleton complex plays a critical role in the adipogenesis of human adipose-derived stem cells. Stem Cell Res Ther 2018; 9:125. [PMID: 29720241 PMCID: PMC5930445 DOI: 10.1186/s13287-018-0836-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2017] [Revised: 02/26/2018] [Accepted: 03/12/2018] [Indexed: 12/28/2022] Open
Abstract
Background Adipose-derived stem cells (ASCs) that show multidifferentiation and anti-immune rejection capacities have been widely used in plastic and reconstructive surgery. Previous studies have indicated that mechanical and biophysical interactions between cells and their surrounding environment regulate essential processes, such as growth, survival, and differentiation, and the cytoskeleton system plays an important role in the mechanotransduction. However, the role of mechanical force in the determination of lineage fate is still unclear. Methods Human ASCs (hASCs) were obtained from three different donors by liposuction. Adipogenesis and osteogenesis were determined by Oil Red O and Alizarin Red staining, respectively. The mRNA levels of the cytoskeleton system, PPARγ, and C/EBPα were determined by real-time polymerase chain reaction (RT-PCR). The level of cytoskeleton, PPARγ, and C/EBPα protein levels were measured by Western blotting. The morphology of the cytoskeleton system during adipogenesis was observed with confocal microscopy. hASCs were transfected with a SUN2-specific shRNA to knockdown sun2, and a nontargeting shRNA was used as a control. Results We found that disrupting the physiological balance between the cytoskeleton and the linker of the nucleoskeleton and cytoskeleton (LINC) complex (especially SUN2) could impact the adipogenesis of hASCs in vitro. Microtubule (MT) depolymerization with nocodazole (which interferes with the polymerization of MTs) increased the expression of SUN2 and PPARγ, while taxol (an inhibitor of MT disassembly) showed the opposite results. Meanwhile, hASCs with sun2 knockdown overexpressed MTs and decreased PPARγ expression, thereby inhibiting the adipogenesis. Furthermore, knockdown of sun2 changed the structure of perinuclear MTs. Conclusions We demonstrated the presence of cross-talk between MT and SUN2, and this cross-talk plays a critical role in the rebalance of the mechanical environment and is involved in the regulation of PPARγ transport during adipogenic differentiation of hASCs. Electronic supplementary material The online version of this article (10.1186/s13287-018-0836-y) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yiting Yang
- Department of Anatomy, Guangdong Provincial Key Laboratory of Medicine and Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Rongmei Qu
- Department of Anatomy, Guangdong Provincial Key Laboratory of Medicine and Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Tingyu Fan
- Department of Anatomy, Guangdong Provincial Key Laboratory of Medicine and Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Xi Zhu
- Departments of Obstetrics and Gynecology, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Yanting Feng
- Department of Anatomy, Guangdong Provincial Key Laboratory of Medicine and Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Yuchao Yang
- Department of Anatomy, Guangdong Provincial Key Laboratory of Medicine and Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Ting Deng
- Department of Anatomy, Guangdong Provincial Key Laboratory of Medicine and Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Yan Peng
- Department of Anatomy, Guangdong Provincial Key Laboratory of Medicine and Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Wenhua Huang
- Department of Anatomy, Guangdong Provincial Key Laboratory of Medicine and Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
| | - Jun Ouyang
- Department of Anatomy, Guangdong Provincial Key Laboratory of Medicine and Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
| | - Jingxing Dai
- Department of Anatomy, Guangdong Provincial Key Laboratory of Medicine and Biomechanics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
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25
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Nesprin-1/2: roles in nuclear envelope organisation, myogenesis and muscle disease. Biochem Soc Trans 2018; 46:311-320. [PMID: 29487227 DOI: 10.1042/bst20170149] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2017] [Revised: 01/12/2018] [Accepted: 01/17/2018] [Indexed: 02/05/2023]
Abstract
Nesprins (nuclear envelope spectrin repeat proteins) are multi-isomeric scaffolding proteins. Nesprin-1 and -2 are highly expressed in skeletal and cardiac muscles and together with SUN (Sad1p/UNC84) domain-containing proteins form the LInker of Nucleoskeleton and Cytoskeleton (LINC) complex at the nuclear envelope in association with lamin A/C and emerin. Mutations in nesprin-1/2 have been found in patients with autosomal dominant Emery-Dreifuss muscular dystrophy (EDMD) as well as dilated cardiomyopathy (DCM). Several lines of evidence indicate that compromised LINC complex function is the critical step leading to muscle disease. Here, we review recent advances in our understanding of the functions of nesprin-1/2 in the LINC complex and mechanistic insights into how mutations in nesprin-1/2 lead to nesprin-related muscle diseases, in particular DCM and EDMD.
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26
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Morgan JT, Robbins AK, Mateson AB, Sawamoto K, Tomatsu S, Gray DR, Gleghorn JP, Barthold JS. Regional Variation in Androgen Receptor Expression and Biomechanical Properties May Contribute to Cryptorchidism Susceptibility in the LE/orl Rat. Front Endocrinol (Lausanne) 2018; 9:738. [PMID: 30568634 PMCID: PMC6290328 DOI: 10.3389/fendo.2018.00738] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 11/20/2018] [Indexed: 11/13/2022] Open
Abstract
Background: The process of testicular descent requires androgen and insulin-like 3, hormones secreted by fetal Leydig cells. Knowledge concerning distinct and common functions of these hormones in regulating development of the fetal gubernaculum remains limited and/or conflicting. The current studies were designed to better define characteristics of androgen receptor (AR) expression, function and regulation, as well as the biomechanical properties of normal and cryptorchid gubernaculum during fetal development. Methods: We studied fetal gubernacula from Long Evans outbred (LE/wt) rats and an inbred (LE/orl) strain with an inherited form of cryptorchidism associated with an AR signaling defect. Gubernacular cells or whole organs obtained from LE/wt and LE/orl fetal gubernacula underwent AR immunostaining and quantitative image analysis. The effects of dihydrotestosterone (DHT) on AR expression, muscle fiber morphology, hyaluronan (HA) levels and glycosaminoglycan (GAG) content were measured in LE/wt gubernacula. Finally, the spatial mechanics of freshly harvested LE/wt and LE/orl fetal gubernacula were compared using micropipette aspiration. Results: AR is expressed in the nucleus of mesenchymal core, tip and cord cells of the embryonic (E) day 17 and 21 fetal gubernaculum, and is enhanced by DHT in primary cultures of gubernacular mesenchymal cells. Enhanced AR expression at the tip was observed in LE/wt but not LE/orl gubernacula. In in vitro studies of whole mount fetal gubernaculum, DHT did not alter muscle fiber morphology, HA content or GAG production. Progressive swelling with reduced cellular density of the LE/wt gubernaculum at E19-21 was associated with increased central stiffness in LE/wt but not in LE/orl fetuses. Conclusions: These data confirm nuclear AR expression in gubernacular mesenchyme with distal enhancement at the tip/cord region in LE/wt but not LE/orl rat fetuses. DHT enhanced cellular AR expression but had no major effects on muscle morphology or matrix composition in the rat fetal gubernaculum in vitro. Regional increased stiffness and decreased cell density between E19 and E21 were observed in LE/wt but not LE/orl fetal gubernacula. Developmental differences in cell-specific AR expression in LE/orl fetal gubernacula may contribute to the dysmorphism and aberrant function that underlies cryptorchidism susceptibility in this strain.
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Affiliation(s)
- Joshua T. Morgan
- Department of Bioengineering, University of California, Riverside, Riverside, CA, United States
- *Correspondence: Joshua T. Morgan
| | - Alan K. Robbins
- Nemours Biomedical Research, Division of Urology, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, United States
| | - Abigail B. Mateson
- Nemours Biomedical Research, Division of Urology, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, United States
| | - Kazuki Sawamoto
- Department of Orthopedics, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, United States
| | - Shunji Tomatsu
- Department of Orthopedics, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, United States
| | - Dione R. Gray
- Nemours Biomedical Research, Division of Urology, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, United States
| | - Jason P. Gleghorn
- Department of Biomedical Engineering, University of Delaware, Newark, DE, United States
| | - Julia Spencer Barthold
- Nemours Biomedical Research, Division of Urology, Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE, United States
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Stroud MJ, Fang X, Veevers J, Chen J. Generation and Analysis of Striated Muscle Selective LINC Complex Protein Mutant Mice. Methods Mol Biol 2018; 1840:251-281. [PMID: 30141050 PMCID: PMC6887482 DOI: 10.1007/978-1-4939-8691-0_18] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
The linker of nucleoskeleton and cytoskeleton (LINC) complex mediates intracellular cross talk between the nucleus and the cytoplasm. In striated muscle, the LINC complex provides structural support to the myocyte nucleus and plays an essential role in regulating gene expression and mechanotransduction. A wide range of cardiac and skeletal myopathies have been linked to mutations in LINC complex proteins. Studies utilizing tissue-specific knockout and mutant mouse models have revealed important insights into the roles of the LINC complex in striated muscle. In this chapter, we describe several feasible approaches for generating striated muscle-specific gene knockout and mutant mouse models to study LINC complex protein function in cardiac and skeletal muscle. The experimental procedures used for phenotyping and analysis of LINC complex knockout mice are also described.
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Affiliation(s)
- Matthew J Stroud
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
- Cardiovascular Division, King's College London, British Heart Foundation Centre of Excellence, London, UK
| | - Xi Fang
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Jennifer Veevers
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Ju Chen
- Department of Medicine, University of California, San Diego, La Jolla, CA, USA.
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28
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Lee YL, Burke B. LINC complexes and nuclear positioning. Semin Cell Dev Biol 2017; 82:67-76. [PMID: 29191370 DOI: 10.1016/j.semcdb.2017.11.008] [Citation(s) in RCA: 66] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Revised: 11/06/2017] [Accepted: 11/06/2017] [Indexed: 12/14/2022]
Abstract
One of the characteristics of eukaryotic cells is their structural plasticity associated with the ability to carry out a broad range of complex functions, both autonomously and as components of tissues and organs. Major cellular rearrangements can be observed in various systems from meiosis in fission yeast, through dermal differentiation in nematodes, to muscle and neuronal development in vertebrates. Each of these processes involves oftentimes dramatic relocation of the nucleus within the cell. During the last decade it has become apparent that the nuclear periphery represents a nexus of cytoskeletal interactions that are involved not only in nuclear movement but also in the distribution and dissemination of mechanical forces throughout the cell. Nucleocytoskeletal coupling is mediated in large part by SUN- and KASH-domain proteins of the nuclear membranes, that together assemble to form LINC (Linker of the Nucleoskeleton and Cytoskeleton) complexes. In this review we will describe how the LINC complex repertoire contributes to nuclear positioning and chromosome dynamics in a variety of cellular contexts.
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Affiliation(s)
- Yin Loon Lee
- Laboratory of Nuclear Dynamics and Architecture, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore
| | - Brian Burke
- Laboratory of Nuclear Dynamics and Architecture, Institute of Medical Biology, 8A Biomedical Grove, Immunos, 138648, Singapore.
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29
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Zhou C, Li C, Zhou B, Sun H, Koullourou V, Holt I, Puckelwartz MJ, Warren DT, Hayward R, Lin Z, Zhang L, Morris GE, McNally EM, Shackleton S, Rao L, Shanahan CM, Zhang Q. Novel nesprin-1 mutations associated with dilated cardiomyopathy cause nuclear envelope disruption and defects in myogenesis. Hum Mol Genet 2017; 26:2258-2276. [PMID: 28398466 PMCID: PMC5458344 DOI: 10.1093/hmg/ddx116] [Citation(s) in RCA: 70] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2017] [Accepted: 03/22/2017] [Indexed: 02/05/2023] Open
Abstract
Nesprins-1 and -2 are highly expressed in skeletal and cardiac muscle and together with SUN (Sad1p/UNC84)-domain containing proteins and lamin A/C form the LInker of Nucleoskeleton-and-Cytoskeleton (LINC) bridging complex at the nuclear envelope (NE). Mutations in nesprin-1/2 have previously been found in patients with autosomal dominant Emery–Dreifuss muscular dystrophy (EDMD) as well as dilated cardiomyopathy (DCM). In this study, three novel rare variants (R8272Q, S8381C and N8406K) in the C-terminus of the SYNE1 gene (nesprin-1) were identified in seven DCM patients by mutation screening. Expression of these mutants caused nuclear morphology defects and reduced lamin A/C and SUN2 staining at the NE. GST pull-down indicated that nesprin-1/lamin/SUN interactions were disrupted. Nesprin-1 mutations were also associated with augmented activation of the ERK pathway in vitro and in hearts in vivo. During C2C12 muscle cell differentiation, nesprin-1 levels are increased concomitantly with kinesin light chain (KLC-1/2) and immunoprecipitation and GST pull-down showed that these proteins interacted via a recently identified LEWD domain in the C-terminus of nesprin-1. Expression of nesprin-1 mutants in C2C12 cells caused defects in myoblast differentiation and fusion associated with dysregulation of myogenic transcription factors and disruption of the nesprin-1 and KLC-1/2 interaction at the outer nuclear membrane. Expression of nesprin-1α2 WT and mutants in zebrafish embryos caused heart developmental defects that varied in severity. These findings support a role for nesprin-1 in myogenesis and muscle disease, and uncover a novel mechanism whereby disruption of the LINC complex may contribute to the pathogenesis of DCM.
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Affiliation(s)
- Can Zhou
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5 9NU, UK.,Department of Cardiology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Chen Li
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5 9NU, UK.,Department of Cardiology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Bin Zhou
- Laboratory of Molecular Translational Medicine.,Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education
| | - Huaqin Sun
- Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education.,SCU-CUHK Joint Laboratory for Reproductive Medicine, West China Second University Hospital, Sichuan University, Chengdu, 610041, China
| | - Victoria Koullourou
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5 9NU, UK.,Department of Molecular and Cell Biology, University of Leicester, Leicester LE1 9HN, UK
| | - Ian Holt
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10?7AG, UK and Institute for Science and Technology in Medicine, Keele University, ST5?5BG, UK
| | - Megan J Puckelwartz
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Derek T Warren
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5?9NU, UK
| | - Robert Hayward
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5?9NU, UK
| | - Ziyuan Lin
- Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education.,SCU-CUHK Joint Laboratory for Reproductive Medicine, West China Second University Hospital, Sichuan University, Chengdu, 610041, China
| | - Lin Zhang
- Laboratory of Molecular Translational Medicine.,Key Laboratory of Obstetric & Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education
| | - Glenn E Morris
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry SY10?7AG, UK and Institute for Science and Technology in Medicine, Keele University, ST5?5BG, UK
| | - Elizabeth M McNally
- Center for Genetic Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Sue Shackleton
- Department of Molecular and Cell Biology, University of Leicester, Leicester LE1?9HN, UK
| | - Li Rao
- Department of Cardiology, West China Hospital of Sichuan University, Chengdu 610041, China
| | - Catherine M Shanahan
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5?9NU, UK
| | - Qiuping Zhang
- King's College London British Heart Foundation Centre of Research Excellence, Cardiovascular Division, London SE5?9NU, UK
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30
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Nesprin-1α-Dependent Microtubule Nucleation from the Nuclear Envelope via Akap450 Is Necessary for Nuclear Positioning in Muscle Cells. Curr Biol 2017; 27:2999-3009.e9. [PMID: 28966089 PMCID: PMC5640514 DOI: 10.1016/j.cub.2017.08.031] [Citation(s) in RCA: 92] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 08/08/2017] [Accepted: 08/15/2017] [Indexed: 11/20/2022]
Abstract
The nucleus is the main microtubule-organizing center (MTOC) in muscle cells due to the accumulation of centrosomal proteins and microtubule (MT) nucleation activity at the nuclear envelope (NE) [1, 2, 3, 4]. The relocalization of centrosomal proteins, including Pericentrin, Pcm1, and γ-tubulin, depends on Nesprin-1, an outer nuclear membrane (ONM) protein that connects the nucleus to the cytoskeleton via its N-terminal region [5, 6, 7]. Nesprins are also involved in the recruitment of kinesin to the NE and play a role in nuclear positioning in skeletal muscle cells [8, 9, 10, 11, 12]. However, a function for MT nucleation from the NE in nuclear positioning has not been established. Using the proximity-dependent biotin identification (BioID) method [13, 14], we found several centrosomal proteins, including Akap450, Pcm1, and Pericentrin, whose association with Nesprin-1α is increased in differentiated myotubes. We show that Nesprin-1α recruits Akap450 to the NE independently of kinesin and that Akap450, but not other centrosomal proteins, is required for MT nucleation from the NE. Furthermore, we demonstrate that this mechanism is disrupted in congenital muscular dystrophy patient myotubes carrying a nonsense mutation within the SYNE1 gene (23560 G>T) encoding Nesprin-1 [15, 16]. Finally, using computer simulation and cell culture systems, we provide evidence for a role of MT nucleation from the NE on nuclear spreading in myotubes. Our data thus reveal a novel function for Nesprin-1α/Nesprin-1 in nuclear positioning through recruitment of Akap450-mediated MT nucleation activity to the NE. BioID of Nesprin-1α identifies centrosomal proteins at myotube nuclear envelope Nesprin-1α-containing LINC complexes recruit Akap450 to myotube nuclear envelope Akap450 is required for microtubule nucleation at the nuclear envelope Microtubule nucleation at the nuclear envelope is involved in nuclear positioning
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31
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Ding ZY, Wang YH, Huang YC, Lee MC, Tseng MJ, Chi YH, Huang ML. Outer nuclear membrane protein Kuduk modulates the LINC complex and nuclear envelope architecture. J Cell Biol 2017; 216:2827-2841. [PMID: 28716842 PMCID: PMC5584142 DOI: 10.1083/jcb.201606043] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 05/25/2017] [Accepted: 06/15/2017] [Indexed: 11/25/2022] Open
Abstract
LINC complexes connect the inner and outer nuclear membrane (ONM) to transduce nucleocytoskeletal force. Ding et al. identify an ONM protein, Kuduk/TMEM258, which modulates the quality of LINC complexes and regulates the nuclear envelope architecture, nuclear positioning, and the development of ovarian follicles. Linker of nucleoskeleton and cytoskeleton (LINC) complexes spanning the nuclear envelope (NE) contribute to nucleocytoskeletal force transduction. A few NE proteins have been found to regulate the LINC complex. In this study, we identify one, Kuduk (Kud), which can reside at the outer nuclear membrane and is required for the development of Drosophila melanogaster ovarian follicles and NE morphology of myonuclei. Kud associates with LINC complex components in an evolutionarily conserved manner. Loss of Kud increases the level but impairs functioning of the LINC complex. Overexpression of Kud suppresses NE targeting of cytoskeleton-free LINC complexes. Thus, Kud acts as a quality control mechanism for LINC-mediated nucleocytoskeletal connections. Genetic data indicate that Kud also functions independently of the LINC complex. Overexpression of the human orthologue TMEM258 in Drosophila proved functional conservation. These findings expand our understanding of the regulation of LINC complexes and NE architecture.
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Affiliation(s)
- Zhao-Ying Ding
- Department of Life Science, National Chung-Cheng University, Chiayi, Taiwan
| | - Ying-Hsuan Wang
- Department of Life Science, National Chung-Cheng University, Chiayi, Taiwan
| | - Yu-Cheng Huang
- Department of Life Science, National Chung-Cheng University, Chiayi, Taiwan
| | - Myong-Chol Lee
- Department of Life Science, National Chung-Cheng University, Chiayi, Taiwan
| | - Min-Jen Tseng
- Department of Life Science, National Chung-Cheng University, Chiayi, Taiwan
| | - Ya-Hui Chi
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Miaoli, Taiwan
| | - Min-Lang Huang
- Department of Life Science, National Chung-Cheng University, Chiayi, Taiwan
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32
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Stroud MJ, Feng W, Zhang J, Veevers J, Fang X, Gerace L, Chen J. Nesprin 1α2 is essential for mouse postnatal viability and nuclear positioning in skeletal muscle. J Cell Biol 2017; 216:1915-1924. [PMID: 28533284 PMCID: PMC5496623 DOI: 10.1083/jcb.201612128] [Citation(s) in RCA: 49] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Revised: 03/08/2017] [Accepted: 04/18/2017] [Indexed: 12/13/2022] Open
Abstract
Defects in nuclear positioning occur in muscle diseases and correlate with muscle dysfunction. In this study, Stroud et al. show that nesprin 1α2 is the fundamental nesprin 1 isoform for nuclear positioning, skeletal muscle function, and postnatal viability. The position of the nucleus in a cell is controlled by interactions between the linker of nucleoskeleton and cytoskeleton (LINC) complex and the cytoskeleton. Defects in nuclear positioning and abnormal aggregation of nuclei occur in many muscle diseases and correlate with muscle dysfunction. Nesprin 1, which includes multiple isoforms, is an integral component of the LINC complex, critical for nuclear positioning and anchorage in skeletal muscle, and is thought to provide an essential link between nuclei and actin. However, previous studies have yet to identify which isoform is responsible. To elucidate this, we generated a series of nesprin 1 mutant mice. We showed that the actin-binding domains of nesprin 1 were dispensable, whereas nesprin 1α2, which lacks actin-binding domains, was crucial for postnatal viability, nuclear positioning, and skeletal muscle function. Furthermore, we revealed that kinesin 1 was displaced in fibers of nesprin 1α2–knockout mice, suggesting that this interaction may play an important role in positioning of myonuclei and functional skeletal muscle.
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Affiliation(s)
- Matthew J Stroud
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Wei Feng
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Jianlin Zhang
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Jennifer Veevers
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Xi Fang
- Department of Medicine, University of California, San Diego, La Jolla, CA
| | - Larry Gerace
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, CA
| | - Ju Chen
- Department of Medicine, University of California, San Diego, La Jolla, CA
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Schwartz C, Fischer M, Mamchaoui K, Bigot A, Lok T, Verdier C, Duperray A, Michel R, Holt I, Voit T, Quijano-Roy S, Bonne G, Coirault C. Lamins and nesprin-1 mediate inside-out mechanical coupling in muscle cell precursors through FHOD1. Sci Rep 2017; 7:1253. [PMID: 28455503 PMCID: PMC5430732 DOI: 10.1038/s41598-017-01324-z] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Accepted: 03/27/2017] [Indexed: 02/03/2023] Open
Abstract
LINC complexes are crucial for the response of muscle cell precursors to the rigidity of their environment, but the mechanisms explaining this behaviour are not known. Here we show that pathogenic mutations in LMNA or SYNE-1 responsible for severe muscle dystrophies reduced the ability of human muscle cell precursors to adapt to substrates of different stiffness. Plated on muscle-like stiffness matrix, mutant cells exhibited contractile stress fibre accumulation, increased focal adhesions, and higher traction force than controls. Inhibition of Rho-associated kinase (ROCK) prevented cytoskeletal defects, while inhibiting myosin light chain kinase or phosphorylation of focal adhesion kinase was ineffective. Depletion or inactivation of a ROCK-dependent regulator of actin remodelling, the formin FHOD1, largely rescued morphology in mutant cells. The functional integrity of lamin and nesprin-1 is thus required to modulate the FHOD1 activity and the inside-out mechanical coupling that tunes the cell internal stiffness to match that of its soft, physiological-like environment.
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Affiliation(s)
- Christine Schwartz
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Centre for Research in Myology, Paris, France
| | - Martina Fischer
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Centre for Research in Myology, Paris, France
| | - Kamel Mamchaoui
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Centre for Research in Myology, Paris, France
| | - Anne Bigot
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Centre for Research in Myology, Paris, France
| | - Thevy Lok
- Univ. Grenoble Alpes, LIPHY, F-38000, Grenoble, France
- CNRS, LIPHY, F-38000, Grenoble, France
| | - Claude Verdier
- Univ. Grenoble Alpes, LIPHY, F-38000, Grenoble, France
- CNRS, LIPHY, F-38000, Grenoble, France
| | - Alain Duperray
- INSERM, Institut Albert Bonniot, U1209, F-38000, Grenoble, France
- Université Grenoble Alpes, IAB, F-38000, Grenoble, France
| | - Richard Michel
- Univ. Grenoble Alpes, LIPHY, F-38000, Grenoble, France
- CNRS, LIPHY, F-38000, Grenoble, France
| | - Ian Holt
- Wolfson Centre for Inherited Neuromuscular Disease, RJAH Orthopaedic Hospital, Oswestry, SY10 7AG, UK
| | - Thomas Voit
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Centre for Research in Myology, Paris, France
- NIHR Great Ormond Street Biomedical Research Centre, Institute of Child Health, University College London, 30 Guilford Street, London, WC1N 1EH, UK
| | | | - Gisèle Bonne
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Centre for Research in Myology, Paris, France
| | - Catherine Coirault
- Sorbonne Universités, UPMC Univ Paris 06, INSERM UMRS974, CNRS FRE3617, Centre for Research in Myology, Paris, France.
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Thakar K, May CK, Rogers A, Carroll CW. Opposing roles for distinct LINC complexes in regulation of the small GTPase RhoA. Mol Biol Cell 2016; 28:182-191. [PMID: 28035049 PMCID: PMC5221622 DOI: 10.1091/mbc.e16-06-0467] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 09/20/2016] [Accepted: 11/02/2016] [Indexed: 12/01/2022] Open
Abstract
Different forms of nuclear envelope–spanning LINC complexes have opposing roles in the transcription-independent control of the small GTPase RhoA. Competition between LINC complexes in the nuclear envelope may therefore dictate the outcome of signaling to cytoskeletal networks. Linker of Nucleoskeleton and Cytoskeleton (LINC) complexes span the nuclear envelope and transduce force from dynamic cytoskeletal networks to the nuclear lamina. Here we show that LINC complexes also signal from the nuclear envelope to critical regulators of the actin cytoskeleton. Specifically, we find that LINC complexes that contain the inner nuclear membrane protein Sun2 promote focal adhesion assembly by activating the small GTPase RhoA. A key effector in this process is the transcription factor/coactivator complex composed of SRF/Mkl1. A constitutively active form of SRF/Mkl1 was not sufficient to induce focal adhesion assembly in cells lacking Sun2, however, suggesting that LINC complexes support RhoA activity through a transcription-independent mechanism. Strikingly, we also find that the inner nuclear membrane protein Sun1 antagonizes Sun2 LINC complexes and inhibits RhoA activation and focal adhesion assembly. Thus different LINC complexes have opposing roles in the transcription-independent control of the actin cytoskeleton through the small GTPase RhoA.
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Affiliation(s)
- Ketan Thakar
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | - Christopher K May
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
| | - Anna Rogers
- Department of Cell Biology, Yale School of Medicine, New Haven, CT 06520
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Baumann M, Steichen-Gersdorf E, Krabichler B, Petersen BS, Weber U, Schmidt WM, Zschocke J, Müller T, Bittner RE, Janecke AR. Homozygous SYNE1 mutation causes congenital onset of muscular weakness with distal arthrogryposis: a genotype-phenotype correlation. Eur J Hum Genet 2016; 25:262-266. [PMID: 27782104 DOI: 10.1038/ejhg.2016.144] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/07/2016] [Accepted: 09/20/2016] [Indexed: 01/15/2023] Open
Abstract
The exceptionally large SYNE1 (spectrin repeat-containing nuclear envelope protein 1) gene encodes different nesprin-1 isoforms, which are differentially expressed in striated muscle and in cerebellar and cerebral neurons. Nesprin-1 isoforms can function in cytoskeletal, nuclear, and vesicle anchoring. SYNE1 variants have been associated with a spectrum of neurological and neuromuscular disease. Homozygosity mapping combined with exome sequencing identified a disease-causing nonsense mutation in the ultimate exon of full-length SYNE1 transcript in an 8-year-old boy with distal arthrogryposis and muscular hypotonia. mRNA analysis showed that the mutant transcript is expressed at wild-type levels. The variant truncates nesprin-1 isoforms for the C-terminal KASH (Klarsicht-ANC-Syne homology) domain. This is the third family with recessive arthrogryposis caused by homozygous distal-truncating SYNE1 variants. There is a SYNE1 genotype-phenotype correlation emerging, with more proximal homozygous SYNE1 variants causing recessive cerebellar ataxia of variable onset (SCAR8; ARCA-1).
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Affiliation(s)
- Matthias Baumann
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | | | - Birgit Krabichler
- Division of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Britt-Sabina Petersen
- Institute of Clinical Molecular Biology, Christian-Albrechts-University Kiel, Kiel, Germany
| | - Ulrike Weber
- Department of Pediatrics, Krankenhaus Dornbirn, Dornbirn, Austria
| | - Wolfgang M Schmidt
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Johannes Zschocke
- Division of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
| | - Thomas Müller
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria
| | - Reginald E Bittner
- Neuromuscular Research Department, Center for Anatomy and Cell Biology, Medical University of Vienna, Vienna, Austria
| | - Andreas R Janecke
- Department of Pediatrics I, Medical University of Innsbruck, Innsbruck, Austria.,Division of Human Genetics, Medical University of Innsbruck, Innsbruck, Austria
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Zhang Q, Minaisah RM, Ferraro E, Li C, Porter LJ, Zhou C, Gao F, Zhang J, Rajgor D, Autore F, Shanahan CM, Warren DT. N-terminal nesprin-2 variants regulate β-catenin signalling. Exp Cell Res 2016; 345:168-79. [PMID: 27321956 PMCID: PMC4948682 DOI: 10.1016/j.yexcr.2016.06.008] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2015] [Revised: 06/13/2016] [Accepted: 06/14/2016] [Indexed: 01/14/2023]
Abstract
The spatial compartmentalisation of biochemical signalling pathways is essential for cell function. Nesprins are a multi-isomeric family of proteins that have emerged as signalling scaffolds, herein, we investigate the localisation and function of novel nesprin-2 N-terminal variants. We show that these nesprin-2 variants display cell specific distribution and reside in both the cytoplasm and nucleus. Immunofluorescence microscopy revealed that nesprin-2 N-terminal variants colocalised with β-catenin at cell-cell junctions in U2OS cells. Calcium switch assays demonstrated that nesprin-2 and β-catenin are lost from cell-cell junctions in low calcium conditions whereas emerin localisation at the NE remained unaltered, furthermore, an N-terminal fragment of nesprin-2 was sufficient for cell-cell junction localisation and interacted with β-catenin. Disruption of these N-terminal nesprin-2 variants, using siRNA depletion resulted in loss of β-catenin from cell-cell junctions, nuclear accumulation of active β-catenin and augmented β-catenin transcriptional activity. Importantly, we show that U2OS cells lack nesprin-2 giant, suggesting that the N-terminal nesprin-2 variants regulate β-catenin signalling independently of the NE. Together, these data identify N-terminal nesprin-2 variants as novel regulators of β-catenin signalling that tether β-catenin to cell-cell contacts to inhibit β-catenin transcriptional activity.
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Affiliation(s)
- Qiuping Zhang
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Rose-Marie Minaisah
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Elisa Ferraro
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Chen Li
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Lauren J Porter
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Can Zhou
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Fang Gao
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Junyi Zhang
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Dipen Rajgor
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Flavia Autore
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Catherine M Shanahan
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK
| | - Derek T Warren
- British Heart Foundation Centre of Research Excellence, Cardiovascular Division, King's College, SE5 9NU London, UK.
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Specific localization of nesprin-1-α2, the short isoform of nesprin-1 with a KASH domain, in developing, fetal and regenerating muscle, using a new monoclonal antibody. BMC Cell Biol 2016; 17:26. [PMID: 27350129 PMCID: PMC4924313 DOI: 10.1186/s12860-016-0105-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 06/20/2016] [Indexed: 01/25/2023] Open
Abstract
Background Nesprin-1-giant (1008kD) is a protein of the outer nuclear membrane that links nuclei to the actin cytoskeleton via amino-terminal calponin homology domains. The short nesprin-1 isoform, nesprin-1-α2, is present only in skeletal and cardiac muscle and several pathogenic mutations occur within it, but the functions of this short isoform without calponin homology domains are unclear. The aim of this study was to determine mRNA levels and protein localization of nesprin-1-α2 at different stages of muscle development in order to shed light on its functions. Results mRNA levels of all known nesprin-1 isoforms with a KASH domain were determined by quantitative PCR. The mRNA for the 111 kD muscle-specific short isoform, nesprin-1-α2, was not detected in pre-differentiation human myoblasts but was present at significant levels in multinucleate myotubes. We developed a monoclonal antibody against the unique amino-terminal sequence of nesprin-1-α2, enabling specific immunolocalization for the first time. Nesprin-1-α2 protein was undetectable in pre-differentiation myoblasts but appeared at the nuclear rim in post-mitotic, multinucleate myotubes and reached its highest levels in fetal muscle. In muscle from a Duchenne muscular dystrophy biopsy, nesprin-1-α2 protein was detected mainly in regenerating fibres expressing neonatal myosin. Nesprin-1-giant was present at all developmental stages, but was also highest in fetal and regenerating fibres. In fetal muscle, both isoforms were present in the cytoplasm, as well as at the nuclear rim. A pathogenic early stop codon (E7854X) in nesprin-1 caused reduced mRNA levels and loss of protein levels of both nesprin-1-giant and (unexpectedly) nesprin-1-α2, but did not affect myogenesis in vitro. Conclusions Nesprin-1-α2 mRNA and protein expression is switched on during myogenesis, alongside other known markers of muscle differentiation. The results show that nesprin-1-α2 is dynamically controlled and may be involved in some process occurring during early myofibre formation, such as re-positioning of nuclei.
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38
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Pitangui NDS, Sardi JDCO, Voltan AR, Dos Santos CT, da Silva JDF, da Silva RAM, Souza FO, Soares CP, Rodríguez-Arellanes G, Taylor ML, Mendes-Giannini MJS, Fusco-Almeida AM. An Intracellular Arrangement of Histoplasma capsulatum Yeast-Aggregates Generates Nuclear Damage to the Cultured Murine Alveolar Macrophages. Front Microbiol 2016; 6:1526. [PMID: 26793172 PMCID: PMC4707385 DOI: 10.3389/fmicb.2015.01526] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 12/18/2015] [Indexed: 11/26/2022] Open
Abstract
Histoplasma capsulatum is responsible for a human systemic mycosis that primarily affects lung tissue. Macrophages are the major effector cells in humans that respond to the fungus, and the development of respiratory disease depends on the ability of Histoplasma yeast cells to survive and replicate within alveolar macrophages. Therefore, the interaction between macrophages and H. capsulatum is a decisive step in the yeast dissemination into host tissues. Although the role played by components of cell-mediated immunity in the host's defense system and the mechanisms used by the pathogen to evade the host immune response are well understood, knowledge regarding the effects induced by H. capsulatum in host cells at the nuclear level is limited. According to the present findings, H. capsulatum yeast cells display a unique architectural arrangement during the intracellular infection of cultured murine alveolar macrophages, characterized as a formation of aggregates that seem to surround the host cell nucleus, resembling a “crown.” This extranuclear organization of yeast-aggregates generates damage on the nucleus of the host cell, producing DNA fragmentation and inducing apoptosis, even though the yeast cells are not located inside the nucleus and do not trigger changes in nuclear proteins. The current study highlights a singular intracellular arrangement of H. capsulatum yeast near to the nucleus of infected murine alveolar macrophages that may contribute to the yeast's persistence under intracellular conditions, since this fungal pathogen may display different strategies to prevent elimination by the host's phagocytic mechanisms.
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Affiliation(s)
- Nayla de Souza Pitangui
- Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Janaina de Cássia Orlandi Sardi
- Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Aline R Voltan
- Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Claudia T Dos Santos
- Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Julhiany de Fátima da Silva
- Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Rosangela A M da Silva
- Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Felipe O Souza
- Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Christiane P Soares
- Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Gabriela Rodríguez-Arellanes
- Departamento de Microbiologia y Parasitologia, Facultad de Medicina, Universidad Nacional Autónoma de México México City, México
| | - Maria Lucia Taylor
- Departamento de Microbiologia y Parasitologia, Facultad de Medicina, Universidad Nacional Autónoma de México México City, México
| | - Maria J S Mendes-Giannini
- Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
| | - Ana M Fusco-Almeida
- Faculdade de Ciências Farmacêuticas, UNESP - Univ Estadual Paulista, Campus Araraquara, Departamento de Análises Clínicas, Laboratório de Micologia Clínica São Paulo, Brazil
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Espigat-Georger A, Dyachuk V, Chemin C, Emorine L, Merdes A. Nuclear alignment in myotubes requires centrosome proteins recruited by nesprin-1. J Cell Sci 2016; 129:4227-4237. [DOI: 10.1242/jcs.191767] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Accepted: 09/26/2016] [Indexed: 01/26/2023] Open
Abstract
Myotubes are syncytial cells, generated by fusion of myoblasts. Among the numerous nuclei in myotubes of skeletal muscle fibres, the majority are equidistantly positioned at the periphery, except for clusters of multiple nuclei underneath the motor endplate. The correct positioning of nuclei is thought to be important for muscle function and requires nesprin-1, a protein of the nuclear envelope. Consistently, mice lacking functional nesprin-1 show defective nuclear positioning and mimic aspects of Emery-Dreifuss muscular dystrophy. In this study, we perform siRNA experiments in C2C12 myoblasts undergoing differentiation, demonstrating that the positioning of nuclei requires PCM-1, a protein of the centrosome that relocalizes to the nuclear envelope at the onset of differentiation, dependent on the presence of nesprin-1. PCM-1 itself is required for recruiting proteins of the dynein/dynactin complex and of kinesin motor complexes. This suggests that microtubule motors that are attached to the nuclear envelope support the movement of nuclei along microtubules, to ensure correct positioning in the myotube.
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Affiliation(s)
- Aude Espigat-Georger
- Centre de Biologie du Développement, Université Paul Sabatier/CNRS, 31062 Toulouse, France
| | - Vyacheslav Dyachuk
- Centre de Biologie du Développement, Université Paul Sabatier/CNRS, 31062 Toulouse, France
| | - Cécile Chemin
- Centre de Biologie du Développement, Université Paul Sabatier/CNRS, 31062 Toulouse, France
| | - Laurent Emorine
- Centre de Biologie du Développement, Université Paul Sabatier/CNRS, 31062 Toulouse, France
| | - Andreas Merdes
- Centre de Biologie du Développement, Université Paul Sabatier/CNRS, 31062 Toulouse, France
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40
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Abstract
Nesprins are a family of multi-isomeric scaffolding proteins that were originally identified at the nuclear envelope (NE), where they bind to lamin A/C, emerin, and SUN-domain containing proteins, to form the LInker of Nucleoskeleton-and-Cytoskeleton (LINC) complex that connects the NE to the actin cytoskeleton. However, nesprin genes also give rise to a variety of tissue-specific variants of different sizes with potential roles beyond the NE. These variants are generated through alternative initiation, termination, and splicing, which makes nesprin biology very complex to study due to the difficulty in generating specific antibodies and/or short interfering RNAs (siRNA) to particular isoforms. In order to distinguish genuine nesprin variants and eliminate confusion with degradation products of larger nesprin isoforms, in this chapter we discuss methods including 5' and 3' Rapid Amplification of cDNA Ends (RACE) and RT-PCR in combination with EST database searching, for identifying and validating putative nesprin isoforms. This information is essential to allow a better understanding of nesprin functions in different cell types.
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Barthold JS, Pugarelli J, MacDonald ML, Ren J, Adetunji MO, Polson SW, Mateson A, Wang Y, Sol-Church K, McCahan SM, Akins RE, Devoto M, Robbins AK. Polygenic inheritance of cryptorchidism susceptibility in the LE/orl rat. Mol Hum Reprod 2016; 22:18-34. [PMID: 26502805 PMCID: PMC4694052 DOI: 10.1093/molehr/gav060] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2015] [Revised: 09/21/2015] [Accepted: 10/22/2015] [Indexed: 01/07/2023] Open
Abstract
STUDY HYPOTHESIS Susceptibility to inherited cryptorchidism in the LE/orl rat may be associated with genetic loci that influence developmental patterning of the gubernaculum by the fetal testis. STUDY FINDING Cryptorchidism in the LE/orl rat is associated with a unique combination of homozygous minor alleles at multiple loci, and the encoded proteins are co-localized with androgen receptor (AR) and Leydig cells in fetal gubernaculum and testis, respectively. WHAT IS KNOWN ALREADY Prior studies have shown aberrant perinatal gubernacular migration, muscle patterning defects and reduced fetal testicular testosterone in the LE/orl strain. In addition, altered expression of androgen-responsive, cytoskeletal and muscle-related transcripts in the LE/orl fetal gubernaculum suggest a role for defective AR signaling in cryptorchidism susceptibility. STUDY DESIGN, SAMPLES/MATERIALS, METHODS The long-term LE/orl colony and short-term colonies of outbred Crl:LE and Crl:SD, and inbred WKY/Ncrl rats were maintained for studies. Animals were intercrossed (LE/orl X WKY/Ncrl), and obligate heterozygotes were reciprocally backcrossed to LE/orl rats to generate 54 F2 males used for genotyping and/or linkage analysis. At least five fetuses per gestational time point from two or more litters were used for quantitative real-time RT-PCR (qRT-PCR) and freshly harvested embryonic (E) day 17 gubernaculum was used to generate conditionally immortalized cell lines. We completed genotyping and gene expression analyses using genome-wide microsatellite markers and single nucleotide polymorphism (SNP) arrays, PCR amplification, direct sequencing, restriction enzyme digest with fragment analysis, whole genome sequencing (WGS), and qRT-PCR. Linkage analysis was performed in Haploview with multiple testing correction, and qRT-PCR data were analyzed using ANOVA after log transformation. Imaging was performed using custom and commercial antibodies directed at candidate proteins in gubernaculum and testis tissues, and gubernaculum cell lines. MAIN RESULTS AND THE ROLE OF CHANCE LE/orl rats showed reduced fertility and fecundity, and higher risk of perinatal death as compared with Crl:LE rats, but there were no differences in breeding outcomes between normal and unilaterally cryptorchid males. Linkage analysis identified multiple peaks, and with selective breeding of outbred Crl:LE and Crl:SD strains for alleles within two of the most significant (P < 0.003) peaks on chromosomes 6 and 16, we were able to generate a non-LE/orl cryptorchid rat. Associated loci contain potentially functional minor alleles (0.25-0.36 in tested rat strains) including an exonic deletion in Syne2, a large intronic insertion in Ncoa4 (an AR coactivator) and potentially deleterious variants in Solh/Capn15, Ankrd28, and Hsd17b2. Existing WGS data indicate that homozygosity for these combined alleles does not occur in any other sequenced rat strain. We observed a modifying effect of the Syne2(del) allele on expression of other candidate genes, particularly Ncoa4, and for muscle and hormone-responsive transcripts. The selected candidate genes/proteins are highly expressed, androgen-responsive and/or co-localized with developing muscle and AR in fetal gubernaculum, and co-localized with Leydig cells in fetal testis. LIMITATIONS, REASONS FOR CAUTION The present study identified multiple cryptorchidism-associated linkage peaks in the LE/orl rat, containing potentially causal alleles. These are strong candidate susceptibility loci, but further studies are needed to demonstrate functional relevance to the phenotype. WIDER IMPLICATIONS OF THE FINDINGS Association data from both human and rat models of spontaneous, nonsyndromic cryptorchidism support a polygenic etiology of the disease. Both the present study and a human genome-wide association study suggest that common variants with weak effects contribute to susceptibility, and may exist in genes encoding proteins that participate in AR signaling in the developing gubernaculum. These findings have potential implications for the gene-environment interaction in the etiology of cryptorchidism. LARGE SCALE DATA Sequences were deposited in the Rat Genome Database (RGD, http://rgd.mcw.edu/). STUDY FUNDING AND COMPETING INTERESTS This work was supported by: R01HD060769 from the Eunice Kennedy Shriver National Institute for Child Health and Human Development (NICHD), 2P20GM103446 and P20GM103464 from the National Institute of General Medical Sciences (NIGMS), and Nemours Biomedical Research. The authors have no competing interests to declare.
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Affiliation(s)
- Julia Spencer Barthold
- Pediatric Urology Research Laboratory, Nemours Biomedical Research/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Joan Pugarelli
- Pediatric Urology Research Laboratory, Nemours Biomedical Research/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Madolyn L MacDonald
- Center for Bioinformatics and Computational Biology, Delaware Biotechnology Institute, University of Delaware, Newark, DE, USA
| | - Jia Ren
- Center for Bioinformatics and Computational Biology, Delaware Biotechnology Institute, University of Delaware, Newark, DE, USA
| | - Modupeore O Adetunji
- Center for Bioinformatics and Computational Biology, Delaware Biotechnology Institute, University of Delaware, Newark, DE, USA
| | - Shawn W Polson
- Center for Bioinformatics and Computational Biology, Delaware Biotechnology Institute, University of Delaware, Newark, DE, USA
| | - Abigail Mateson
- Pediatric Urology Research Laboratory, Nemours Biomedical Research/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Yanping Wang
- Pediatric Urology Research Laboratory, Nemours Biomedical Research/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Katia Sol-Church
- Biomolecular Core Laboratory, Nemours Biomedical Research/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Suzanne M McCahan
- Bioinformatics Core, Nemours Biomedical Research/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Robert E Akins
- Tissue Engineering and Regenerative Medicine Research Laboratory, Nemours Biomedical Research/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
| | - Marcella Devoto
- Department of Pediatrics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA Department of Biostatistics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA Department of Epidemiology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA Department of Molecular Medicine, Sapienza University, Rome, Italy
| | - Alan K Robbins
- Pediatric Urology Research Laboratory, Nemours Biomedical Research/Alfred I. duPont Hospital for Children, Wilmington, DE, USA
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Thomas DG, Yenepalli A, Denais CM, Rape A, Beach JR, Wang YL, Schiemann WP, Baskaran H, Lammerding J, Egelhoff TT. Non-muscle myosin IIB is critical for nuclear translocation during 3D invasion. J Cell Biol 2015; 210:583-94. [PMID: 26261182 PMCID: PMC4539979 DOI: 10.1083/jcb.201502039] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 07/01/2015] [Indexed: 01/22/2023] Open
Abstract
Non-muscle myosin II (NMII) is reported to play multiple roles during cell migration and invasion. However, the exact biophysical roles of different NMII isoforms during these processes remain poorly understood. We analyzed the contributions of NMIIA and NMIIB in three-dimensional (3D) migration and in generating the forces required for efficient invasion by mammary gland carcinoma cells. Using traction force microscopy and microfluidic invasion devices, we demonstrated that NMIIA is critical for generating force during active protrusion, and NMIIB plays a major role in applying force on the nucleus to facilitate nuclear translocation through tight spaces. We further demonstrate that the nuclear membrane protein nesprin-2 is a possible linker coupling NMIIB-based force generation to nuclear translocation. Together, these data reveal a central biophysical role for NMIIB in nuclear translocation during 3D invasive migration, a result with relevance not only to cancer metastasis but for 3D migration in other settings such as embryonic cell migration and wound healing.
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Affiliation(s)
- Dustin G Thomas
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 441195 Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195
| | - Aishwarya Yenepalli
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 441195
| | - Celine Marie Denais
- Department of Biomedical Engineering, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Andrew Rape
- Department of Bioengineering, University of California, Berkeley, Berkeley, CA 94720
| | - Jordan R Beach
- Cell Biology and Physiology Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892
| | - Yu-Li Wang
- Department of Biomedical Engineering, Carnegie Melon University, Pittsburgh, PA 15219
| | - William P Schiemann
- General Medical Sciences-Oncology, Case Comprehensive Cancer Center, Case Western Reserve University, Cleveland, OH 44106
| | - Harihara Baskaran
- Department of Biomedical Engineering, Case Western Reserve University, Cleveland, OH 44106
| | - Jan Lammerding
- Department of Biomedical Engineering, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Thomas T Egelhoff
- Department of Cellular and Molecular Medicine, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 441195 Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine of Case Western Reserve University, Cleveland, OH 44195
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43
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Worman HJ, Schirmer EC. Nuclear membrane diversity: underlying tissue-specific pathologies in disease? Curr Opin Cell Biol 2015; 34:101-12. [PMID: 26115475 PMCID: PMC4522394 DOI: 10.1016/j.ceb.2015.06.003] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 06/05/2015] [Accepted: 06/10/2015] [Indexed: 11/16/2022]
Abstract
Human 'laminopathy' diseases result from mutations in genes encoding nuclear lamins or nuclear envelope (NE) transmembrane proteins (NETs). These diseases present a seeming paradox: the mutated proteins are widely expressed yet pathology is limited to specific tissues. New findings suggest tissue-specific pathologies arise because these widely expressed proteins act in various complexes that include tissue-specific components. Diverse mechanisms to achieve NE tissue-specificity include tissue-specific regulation of the expression, mRNA splicing, signaling, NE-localization and interactions of potentially hundreds of tissue-specific NETs. New findings suggest these NETs underlie tissue-specific NE roles in cytoskeletal mechanics, cell-cycle regulation, signaling, gene expression and genome organization. This view of the NE as 'specialized' in each cell type is important to understand the tissue-specific pathology of NE-linked diseases.
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Affiliation(s)
- Howard J Worman
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, USA; Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, USA
| | - Eric C Schirmer
- Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh, UK.
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Wang JY, Yu IS, Huang CC, Chen CY, Wang WP, Lin SW, Jeang KT, Chi YH. Sun1 deficiency leads to cerebellar ataxia in mice. Dis Model Mech 2015; 8:957-67. [PMID: 26035387 PMCID: PMC4527285 DOI: 10.1242/dmm.019240] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Accepted: 04/23/2015] [Indexed: 01/22/2023] Open
Abstract
Migration and organization of the nucleus are essential for the proliferation and differentiation of cells, including neurons. However, the relationship between the positioning of the nucleus and cellular morphogenesis remains poorly understood. Inherited recessive cerebellar ataxia has been attributed to mutations in SYNE1, a component of the linker of nucleoskeleton and cytoskeleton (LINC) complex. Regardless, Syne1-mutant mice present with normal cerebellar development. The Sad1-Unc-84 homology (SUN)-domain proteins are located at the inner nuclear membrane and recruit Syne proteins through the KASH domain to the outer nuclear membrane. Here, we report an unrecognized contribution of Sun1 and Sun2 to the postnatal development of murine cerebellum. Mice depleted of Sun1 showed a marked reduction in the cerebellar volume, and this phenotype is exacerbated with additional loss of a Sun2 allele. Consistent with these histological changes, Sun1(-/-) and Sun1(-/-)Sun2(+/-) mice exhibited defective motor coordination. Results of immunohistochemical analyses suggested that Sun1 is highly expressed in Purkinje cells and recruits Syne2 to the periphery of the nucleus. Approximately 33% of Purkinje cells in Sun1(-/-) mice and 66% of Purkinje cells in Sun1(-/-)Sun2(+/-) mice were absent from the surface of the internal granule layer (IGL), whereas the proliferation and migration of granule neurons were unaffected. Furthermore, the Sun1(-/-)Sun2(+/-) Purkinje cells exhibited retarded primary dendrite specification, reduced dendritic complexity and aberrant patterning of synapses. Our findings reveal a cell-type-specific role for Sun1 and Sun2 in nucleokinesis during cerebellar development, and we propose the use of Sun-deficient mice as a model for studying cerebellar ataxia that is associated with mutation of human SYNE genes or loss of Purkinje cells.
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Affiliation(s)
- Jing-Ya Wang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan
| | - I-Shing Yu
- Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University Hospital, Taipei 10048, Taiwan Center of Genomic Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei 10048, Taiwan
| | - Chien-Chi Huang
- Institute of Molecular and Genomic Medicine, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan
| | - Chia-Yen Chen
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Wan-Ping Wang
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan
| | - Shu-Wha Lin
- Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University Hospital, Taipei 10048, Taiwan Center of Genomic Medicine, National Taiwan University Hospital, College of Medicine, National Taiwan University, Taipei 10048, Taiwan Department of Laboratory Medicine, National Taiwan University Hospital, Taipei 10048, Taiwan
| | - Kuan-Teh Jeang
- Laboratory of Molecular Microbiology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Ya-Hui Chi
- Institute of Biotechnology and Pharmaceutical Research, National Health Research Institutes, Zhunan, Miaoli County 35053, Taiwan Graduate Institute of Basic Medical Science, China Medical University, Taichung 40402, Taiwan
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45
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Talamas JA, Capelson M. Nuclear envelope and genome interactions in cell fate. Front Genet 2015; 6:95. [PMID: 25852741 PMCID: PMC4365743 DOI: 10.3389/fgene.2015.00095] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Accepted: 02/22/2015] [Indexed: 12/14/2022] Open
Abstract
The eukaryotic cell nucleus houses an organism’s genome and is the location within the cell where all signaling induced and development-driven gene expression programs are ultimately specified. The genome is enclosed and separated from the cytoplasm by the nuclear envelope (NE), a double-lipid membrane bilayer, which contains a large variety of trans-membrane and associated protein complexes. In recent years, research regarding multiple aspects of the cell nucleus points to a highly dynamic and coordinated concert of efforts between chromatin and the NE in regulation of gene expression. Details of how this concert is orchestrated and how it directs cell differentiation and disease are coming to light at a rapid pace. Here we review existing and emerging concepts of how interactions between the genome and the NE may contribute to tissue specific gene expression programs to determine cell fate.
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Affiliation(s)
- Jessica A Talamas
- Program in Epigenetics, Department of Cell and Developmental Biology, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania Philadelphia, PA, USA
| | - Maya Capelson
- Program in Epigenetics, Department of Cell and Developmental Biology, Smilow Center for Translational Research, Perelman School of Medicine, University of Pennsylvania Philadelphia, PA, USA
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46
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Wilson MH, Holzbaur ELF. Nesprins anchor kinesin-1 motors to the nucleus to drive nuclear distribution in muscle cells. Development 2015; 142:218-28. [PMID: 25516977 DOI: 10.1242/dev.114769] [Citation(s) in RCA: 111] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
During skeletal muscle development, nuclei move dynamically through myotubes in a microtubule-dependent manner, driven by the microtubule motor protein kinesin-1. Loss of kinesin-1 leads to improperly positioned nuclei in culture and in vivo. Two models have been proposed to explain how kinesin-1 functions to move nuclei in myotubes. In the cargo model, kinesin-1 acts directly from the surface of the nucleus, whereas in an alternative model, kinesin-1 moves nuclei indirectly by sliding anti-parallel microtubules. Here, we test the hypothesis that an ensemble of Kif5B motors acts from the nuclear envelope to distribute nuclei throughout the length of syncytial myotubes. First, using an inducible dimerization system, we show that controlled recruitment of truncated, constitutively active kinesin-1 motors to the nuclear envelope is sufficient to prevent the nuclear aggregation resulting from depletion of endogenous kinesin-1. Second, we identify a conserved kinesin light chain (KLC)-binding motif in the nuclear envelope proteins nesprin-1 and nesprin-2, and show that recruitment of the motor complex to the nucleus via this LEWD motif is essential for nuclear distribution. Together, our findings demonstrate that the nucleus is a kinesin-1 cargo in myotubes and that nesprins function as nuclear cargo adaptors. The importance of achieving and maintaining proper nuclear position is not restricted to muscle fibers, suggesting that the nesprin-dependent recruitment of kinesin-1 to the nuclear envelope through the interaction of a conserved LEWD motif with kinesin light chain might be a general mechanism for cell-type-specific nuclear positioning during development.
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Affiliation(s)
- Meredith H Wilson
- Department of Physiology and the Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Erika L F Holzbaur
- Department of Physiology and the Pennsylvania Muscle Institute, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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47
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Yang W, Zheng H, Wang Y, Lian F, Hu Z, Xue S. Nesprin-1 has key roles in the process of mesenchymal stem cell differentiation into cardiomyocyte-like cells in vivo and in vitro. Mol Med Rep 2014; 11:133-42. [PMID: 25339194 PMCID: PMC4237090 DOI: 10.3892/mmr.2014.2754] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 09/24/2014] [Indexed: 12/31/2022] Open
Abstract
The aim of the present study was to investigate the expression of nesprin-1 protein in MSCs and its effects on the differentiation of rat bone-marrow mesenchymal stem cells (MSCs). Surface-associated antigens of MSCs were detected by flow cytometry. MSC differentiation was induced by treatment with 10 μmol/l 5-azacytidine. Sprague-Dawley rats were anesthetized prior to thoracotomy and subsequent ligation of the left anterior descending coronary artery to establish a model of myocardial infarction. Two weeks following myocardial infarction, DAPI-marked MSCs were injected into the infarcted region in the experimental group, while DMEM was injected into the infarcted region of the control group. Characteristics of the putative cardiac-myogenic cells were evaluated using immunohistochemical and immunofluorescent analysis. The messenger RNA expression levels of cardiac-myogenic specific genes; desmin, α-actinin and cardiac troponin I (cTnI) were detected by reverse transcription quantitative polymerase chain reaction. The expression of nesprin-1 protein in MSCs was identified by immunofluorescence and western blot analysis, prior to and following MSC differentiation. Following differentiation, the MSCs appeared spindle-shaped with irregular processes and were positive for CD90 and CD29, but negative for CD45. Cardiomyocyte-like cells were positive for desmin, α-sarcomeric actin and cTnI. Nesprin protein was detected in the nuclear membrane via immunofluorescence, and following MSC differentiation into cardiomyocyte-like cells, the expression of nesprin protein was significantly higher (*P=0.03<0.05). The results of the present study indicated that MSCs may be differentiated in vitro and in vivo into cells with characteristics commonly attributed to cardiomyocytes. Cardiomyocyte-like cells cultured from bone marrow sources may be potentially useful for repairing the injured myocardium. The results also suggested that, consistent with the results of previous studies, the expression of nesprin-1 protein was higher during the differentiation process of MSCs and may have an important role in mediating MSC differentiation. Elucidation of the role of nesprin-1 in MSC differentiation may aid in the development of novel therapies for the treatment of myocardial ischemia and nesprin-1 genetic deficiencies.
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Affiliation(s)
- Wengang Yang
- Department of Cardiovascular Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Hui Zheng
- Department of Cardiovascular Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Yongyi Wang
- Department of Cardiovascular Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Feng Lian
- Department of Cardiovascular Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Zhenglei Hu
- Department of Cardiovascular Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
| | - Song Xue
- Department of Cardiovascular Surgery, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai 200127, P.R. China
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48
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Rajgor D, Mellad JA, Soong D, Rattner JB, Fritzler MJ, Shanahan CM. Mammalian microtubule P-body dynamics are mediated by nesprin-1. ACTA ACUST UNITED AC 2014; 205:457-75. [PMID: 24862572 PMCID: PMC4033771 DOI: 10.1083/jcb.201306076] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Nesprins are a multi-isomeric family of spectrin-repeat (SR) proteins, predominantly known as nuclear envelope scaffolds. However, isoforms that function beyond the nuclear envelope remain poorly examined. Here, we characterize p50(Nesp1), a 50-kD isoform that localizes to processing bodies (PBs), where it acts as a microtubule-associated protein capable of linking mRNP complexes to microtubules. Overexpression of dominant-negative p50(Nesp1) caused Rck/p54, but not GW182, displacement from microtubules, resulting in reduced PB movement and cross talk with stress granules (SGs). These cells disassembled canonical SGs induced by sodium arsenite, but not those induced by hydrogen peroxide, leading to cell death and revealing PB-microtubule attachment is required for hydrogen peroxide-induced SG anti-apoptotic functions. Furthermore, p50(Nesp1) was required for miRNA-mediated silencing and interacted with core miRISC silencers Ago2 and Rck/p54 in an RNA-dependent manner and with GW182 in a microtubule-dependent manner. These data identify p50(Nesp1) as a multi-functional PB component and microtubule scaffold necessary for RNA granule dynamics and provides evidence for PB and SG micro-heterogeneity.
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Affiliation(s)
- Dipen Rajgor
- Cardiovascular Division, BHF Centre of Excellence, James Black Centre, King's College London, London SE5 9NU, England, UK
| | - Jason A Mellad
- Cardiovascular Division, BHF Centre of Excellence, James Black Centre, King's College London, London SE5 9NU, England, UK
| | - Daniel Soong
- Cardiovascular Division, BHF Centre of Excellence, James Black Centre, King's College London, London SE5 9NU, England, UK
| | - Jerome B Rattner
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary T2N 4N1, Alberta, Canada
| | - Marvin J Fritzler
- Department of Biochemistry and Molecular Biology, University of Calgary, Calgary T2N 4N1, Alberta, Canada
| | - Catherine M Shanahan
- Cardiovascular Division, BHF Centre of Excellence, James Black Centre, King's College London, London SE5 9NU, England, UK
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49
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Meinke P, Mattioli E, Haque F, Antoku S, Columbaro M, Straatman KR, Worman HJ, Gundersen GG, Lattanzi G, Wehnert M, Shackleton S. Muscular dystrophy-associated SUN1 and SUN2 variants disrupt nuclear-cytoskeletal connections and myonuclear organization. PLoS Genet 2014; 10:e1004605. [PMID: 25210889 PMCID: PMC4161305 DOI: 10.1371/journal.pgen.1004605] [Citation(s) in RCA: 125] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Accepted: 07/16/2014] [Indexed: 11/19/2022] Open
Abstract
Proteins of the nuclear envelope (NE) are associated with a range of inherited disorders, most commonly involving muscular dystrophy and cardiomyopathy, as exemplified by Emery-Dreifuss muscular dystrophy (EDMD). EDMD is both genetically and phenotypically variable, and some evidence of modifier genes has been reported. Six genes have so far been linked to EDMD, four encoding proteins associated with the LINC complex that connects the nucleus to the cytoskeleton. However, 50% of patients have no identifiable mutations in these genes. Using a candidate approach, we have identified putative disease-causing variants in the SUN1 and SUN2 genes, also encoding LINC complex components, in patients with EDMD and related myopathies. Our data also suggest that SUN1 and SUN2 can act as disease modifier genes in individuals with co-segregating mutations in other EDMD genes. Five SUN1/SUN2 variants examined impaired rearward nuclear repositioning in fibroblasts, confirming defective LINC complex function in nuclear-cytoskeletal coupling. Furthermore, myotubes from a patient carrying compound heterozygous SUN1 mutations displayed gross defects in myonuclear organization. This was accompanied by loss of recruitment of centrosomal marker, pericentrin, to the NE and impaired microtubule nucleation at the NE, events that are required for correct myonuclear arrangement. These defects were recapitulated in C2C12 myotubes expressing exogenous SUN1 variants, demonstrating a direct link between SUN1 mutation and impairment of nuclear-microtubule coupling and myonuclear positioning. Our findings strongly support an important role for SUN1 and SUN2 in muscle disease pathogenesis and support the hypothesis that defects in the LINC complex contribute to disease pathology through disruption of nuclear-microtubule association, resulting in defective myonuclear positioning. Emery-Dreifuss muscular dystrophy (EDMD) is an inherited disorder involving muscle wasting and weakness, accompanied by cardiac defects. The disease is variable in its severity and also in its genetic cause. So far, 6 genes have been linked to EDMD, most encoding proteins that form a structural network that supports the nucleus of the cell and connects it to structural elements of the cytoplasm. This network is particularly important in muscle cells, providing resistance to mechanical strain. Weakening of this network is thought to contribute to development of muscle disease in these patients. Despite rigorous screening, at least 50% of patients with EDMD have no detectable mutation in the 6 known genes. We therefore undertook screening and identified mutations in two additional genes that encode other components of the nuclear structural network, SUN1 and SUN2. Our findings add to the genetic complexity of this disease since some individuals carry mutations in more than one gene. We also show that the mutations disrupt connections between the nucleus and the structural elements of cytoplasm, leading to mis-positioning and clustering of nuclei in muscle cells. This nuclear mis-positioning is likely to be another factor contributing to pathogenesis of EDMD.
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Affiliation(s)
- Peter Meinke
- Institute of Human Genetics and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
| | - Elisabetta Mattioli
- National Research Council of Italy - CNR - Institute for Molecular Genetics, Unit of Bologna IOR, Bologna, Italy
- Rizzoli Orthopaedic Institute, Laboratory of Musculoskeletal Cell Biology, Bologna, Italy
| | - Farhana Haque
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
| | - Susumu Antoku
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
| | - Marta Columbaro
- Rizzoli Orthopaedic Institute, Laboratory of Musculoskeletal Cell Biology, Bologna, Italy
| | - Kees R. Straatman
- Centre for Core Biotechnology Services, University of Leicester, Leicester, United Kingdom
| | - Howard J. Worman
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
- Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
| | - Gregg G. Gundersen
- Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, New York, United States of America
| | - Giovanna Lattanzi
- National Research Council of Italy - CNR - Institute for Molecular Genetics, Unit of Bologna IOR, Bologna, Italy
- Rizzoli Orthopaedic Institute, Laboratory of Musculoskeletal Cell Biology, Bologna, Italy
| | - Manfred Wehnert
- Institute of Human Genetics and Interfaculty Institute of Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany
| | - Sue Shackleton
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
- * E-mail:
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50
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King SJ, Nowak K, Suryavanshi N, Holt I, Shanahan CM, Ridley AJ. Nesprin-1 and nesprin-2 regulate endothelial cell shape and migration. Cytoskeleton (Hoboken) 2014; 71:423-34. [PMID: 24931616 DOI: 10.1002/cm.21182] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Revised: 06/06/2014] [Accepted: 06/09/2014] [Indexed: 12/26/2022]
Abstract
Nesprins are large multi-domain proteins that link the nuclear envelope to the cytoskeleton and nucleoskeleton. Here we show that nesprin-1 and nesprin-2 play important roles in regulating cell shape and migration in endothelial cells. Nesprin-1 or nesprin-2 depletion by RNAi increased endothelial cell spread area and the length of cellular protrusions, as well as stimulating stress fibre assembly which correlated with an increase in F-actin levels. Nuclear area was also increased by nesprin depletion, and localization of the inner nuclear membrane protein emerin to the nuclear envelope was reduced. Depletion of nesprin-1 or nesprin-2 reduced migration of endothelial cells into a cell-free area, and decreased loop formation in an in vitro angiogenesis assay. Taken together, our results indicate that nesprin-1 and nesprin-2 both regulate nuclear and cytoplasmic architecture, which we propose leads to their effects on endothelial cell migration and angiogenic loop formation.
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Affiliation(s)
- Samantha J King
- Randall Division of Cell and Molecular Biophysics, King's College London, New Hunt's House, Guy's Campus, London, SE1 1UL, United Kingdom; Cardiovascular Division and British Heart Foundation Centre of Research Excellence, King's College London, James Black Centre, Denmark Hill Campus, London, SE5 9NU, United Kingdom
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