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Evangelisti C, Rusciano I, Mongiorgi S, Ramazzotti G, Lattanzi G, Manzoli L, Cocco L, Ratti S. The wide and growing range of lamin B-related diseases: from laminopathies to cancer. Cell Mol Life Sci 2022; 79:126. [PMID: 35132494 PMCID: PMC8821503 DOI: 10.1007/s00018-021-04084-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/03/2021] [Accepted: 12/08/2021] [Indexed: 12/18/2022]
Abstract
B-type lamins are fundamental components of the nuclear lamina, a complex structure that acts as a scaffold for organization and function of the nucleus. Lamin B1 and B2, the most represented isoforms, are encoded by LMNB1 and LMNB2 gene, respectively. All B-type lamins are synthesized as precursors and undergo sequential post-translational modifications to generate the mature protein. B-type lamins are involved in a wide range of nuclear functions, including DNA replication and repair, regulation of chromatin and nuclear stiffness. Moreover, lamins B1 and B2 regulate several cellular processes, such as tissue development, cell cycle, cellular proliferation, senescence, and DNA damage response. During embryogenesis, B-type lamins are essential for organogenesis, in particular for brain development. As expected from the numerous and pivotal functions of B-type lamins, mutations in their genes or fluctuations in their expression levels are critical for the onset of several diseases. Indeed, a growing range of human disorders have been linked to lamin B1 or B2, increasing the complexity of the group of diseases collectively known as laminopathies. This review highlights the recent findings on the biological role of B-type lamins under physiological or pathological conditions, with a particular emphasis on brain disorders and cancer.
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Affiliation(s)
- Camilla Evangelisti
- Cellular Signalling Laboratory, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Isabella Rusciano
- Cellular Signalling Laboratory, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Sara Mongiorgi
- Cellular Signalling Laboratory, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Giulia Ramazzotti
- Cellular Signalling Laboratory, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
| | - Giovanna Lattanzi
- CNR Institute of Molecular Genetics "Luigi Luca Cavalli-Sforza", Unit of Bologna, Bologna, Italy
- IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy
| | - Lucia Manzoli
- Cellular Signalling Laboratory, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy.
| | - Lucio Cocco
- Cellular Signalling Laboratory, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy.
| | - Stefano Ratti
- Cellular Signalling Laboratory, Department of Biomedical and NeuroMotor Sciences (DIBINEM), University of Bologna, Bologna, Italy
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2
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Zhao CC, Chen J, Zhang LY, Liu H, Zhang CG, Liu Y. Lamin B2 promotes the progression of triple negative breast cancer via mediating cell proliferation and apoptosis. Biosci Rep 2021; 41:BSR20203874. [PMID: 33416073 PMCID: PMC7846963 DOI: 10.1042/bsr20203874] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 12/29/2020] [Accepted: 01/06/2021] [Indexed: 12/28/2022] Open
Abstract
Triple negative breast cancer (TNBC) is a more common type of breast cancer with high distant metastasis and poor prognosis. The potential role of lamins in cancer progression has been widely revealed. However, the function of lamin B2 (LMNB2) in TNBC progression is still unclear. The present study aimed to investigate the role of LMNB2 in TNBC. The cancer genome atlas (TCGA) database analysis and immunohistochemistry (IHC) were performed to examine LMNB2 expression levels. LMNB2 short hairpin RNA plasmid or lentivirus was used to deplete the expression of LMNB2 in human TNBC cell lines including MDA-MB-468 and MDA-MB-231. Alterations in cell proliferation and apoptosis in vitro and the nude mouse tumorigenicity assay in vivo were subsequently analyzed. The human TNBC tissues shown high expression of LMNB2 according to the bioinformation analysis and IHC assays. LMNB2 expression was correlated with the clinical pathological features of TNBC patients, including pTNM stage and lymph node metastasis. Through in vitro and in vivo assays, we confirmed LMNB2 depletion suppressed the proliferation and induced the apoptosis of TNBC cells, and inhibited tumor growth of TNBC cells in mice, with the decrease in Ki67 expression or the increase in caspase-3 expression. In conclusion, LMNB2 may promote TNBC progression and could serve as a potential therapeutic target for TNBC treatment.
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Affiliation(s)
- Cui-Cui Zhao
- Department of VIP Ward, Tianjin Medical University Cancer Institute and Hospital, Tianjin, P.R. China
- National Clinical Research Center for Cancer, Tianjin’s Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, P.R. China
- Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, P.R. China
| | - Jing Chen
- National Clinical Research Center for Cancer, Tianjin’s Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, P.R. China
- Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, P.R. China
- Department of Pancreatic Oncology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, P.R. China
| | - Li-Ying Zhang
- Department of internal medicine, Mudanjiang Cancer Hospital, Mudanjiang, P.R. China
| | - Hong Liu
- National Clinical Research Center for Cancer, Tianjin’s Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, P.R. China
- Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, P.R. China
- Second Department of Breast Surgery, Tianjin Medical University Cancer Institute and Hospital, Tianjin, P.R. China
| | - Chuan-Gui Zhang
- Department of VIP Ward, Tianjin Medical University Cancer Institute and Hospital, Tianjin, P.R. China
- National Clinical Research Center for Cancer, Tianjin’s Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, P.R. China
- Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, P.R. China
| | - Yan Liu
- Department of VIP Ward, Tianjin Medical University Cancer Institute and Hospital, Tianjin, P.R. China
- National Clinical Research Center for Cancer, Tianjin’s Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin, P.R. China
- Key Laboratory of Breast Cancer Prevention and Therapy, Tianjin Medical University, Ministry of Education, Tianjin, P.R. China
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Liu S, Wu Y, Yang L, Li X, Huang L, Xing X. [Functions of lamin B1 and the new progress of its roles in neurological diseases and tumors]. Sheng Wu Gong Cheng Xue Bao 2018; 34:1742-1749. [PMID: 30499270 DOI: 10.13345/j.cjb.180063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lamin B1 is one of the essential members of the nuclear lamina protein family. Its main function is to maintain the integrity of nuclear skeleton, as well as to participate in the cell proliferation and aging by affecting the chromosome distribution. gene expression, and DNA damage repair. The abnormal expression of lamin B1 is related to certain diseases, including neurological diseases [e.g. neural tube defects (NDTs), adult-onset autosomal dominant leukodystrophy (ADLD)] and tumors (e.g. pancreatic cancer). It is also a potential tumor marker as well as drug target. Further research on lamin B1 will help people understand the molecular mechanism of the emergence and development of neural system diseases and tumors, and define a new future in drug target.
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Affiliation(s)
- Siyang Liu
- Department of Clinical Laboratory, the Third Xiangya Hospital of Central South University, Changsha 410013, Hunan, China
- Center for Experimental Medicine Research, the Third Xiangya Hospital of Central South University, Changsha 410013, Hunan, China
| | - Yong Wu
- Department of Clinical Laboratory, the Third Xiangya Hospital of Central South University, Changsha 410013, Hunan, China
| | - Linfei Yang
- Center for Experimental Medicine Research, the Third Xiangya Hospital of Central South University, Changsha 410013, Hunan, China
| | - Xiaohua Li
- Center for Experimental Medicine Research, the Third Xiangya Hospital of Central South University, Changsha 410013, Hunan, China
| | - Lihua Huang
- Center for Experimental Medicine Research, the Third Xiangya Hospital of Central South University, Changsha 410013, Hunan, China
| | - Xiaowei Xing
- Center for Experimental Medicine Research, the Third Xiangya Hospital of Central South University, Changsha 410013, Hunan, China
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Buxboim A, Irianto J, Swift J, Athirasala A, Shin JW, Rehfeldt F, Discher DE. Coordinated increase of nuclear tension and lamin-A with matrix stiffness outcompetes lamin-B receptor that favors soft tissue phenotypes. Mol Biol Cell 2017; 28:3333-3348. [PMID: 28931598 PMCID: PMC5687034 DOI: 10.1091/mbc.e17-06-0393] [Citation(s) in RCA: 71] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Revised: 09/06/2017] [Accepted: 09/13/2017] [Indexed: 12/31/2022] Open
Abstract
Matrix stiffness that is sensed by a cell or measured by a purely physical probe reflects the intrinsic elasticity of the matrix and also how thick or thin the matrix is. Here, mesenchymal stem cells (MSCs) and their nuclei spread in response to thickness-corrected matrix microelasticity, with increases in nuclear tension and nuclear stiffness resulting from increases in myosin-II and lamin-A,C. Linearity between the widely varying projected area of a cell and its nucleus across many matrices, timescales, and myosin-II activity levels indicates a constant ratio of nucleus-to-cell volume, despite MSCs' lineage plasticity. Nuclear envelope fluctuations are suppressed on the stiffest matrices, and fluctuation spectra reveal a high nuclear tension that matches trends from traction force microscopy and from increased lamin-A,C. Transcriptomes of many diverse tissues and MSCs further show that lamin-A,C's increase with tissue or matrix stiffness anti-correlates with lamin-B receptor (LBR), which contributes to lipid/sterol biosynthesis. Adipogenesis (a soft lineage) indeed increases LBR:lamin-A,C protein stoichiometry in MSCs versus osteogenesis (stiff). The two factors compete for lamin-B in response to matrix elasticity, knockdown, myosin-II inhibition, and even constricted migration that disrupts and segregates lamins in situ. Matrix stiffness-driven contractility thus tenses the nucleus to favor lamin-A,C accumulation and suppress soft tissue phenotypes.
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Affiliation(s)
- Amnon Buxboim
- Molecular and Cell Biophysics Laboratory, University of Pennsylvania, Philadelphia, PA 19104
- Department/Graduate Group of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104
| | - Jerome Irianto
- Molecular and Cell Biophysics Laboratory, University of Pennsylvania, Philadelphia, PA 19104
| | - Joe Swift
- Molecular and Cell Biophysics Laboratory, University of Pennsylvania, Philadelphia, PA 19104
| | - Avathamsa Athirasala
- Molecular and Cell Biophysics Laboratory, University of Pennsylvania, Philadelphia, PA 19104
| | - Jae-Won Shin
- Molecular and Cell Biophysics Laboratory, University of Pennsylvania, Philadelphia, PA 19104
| | - Florian Rehfeldt
- Molecular and Cell Biophysics Laboratory, University of Pennsylvania, Philadelphia, PA 19104
| | - Dennis E Discher
- Molecular and Cell Biophysics Laboratory, University of Pennsylvania, Philadelphia, PA 19104
- Department/Graduate Group of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104
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Giacomini C, Mahajani S, Ruffilli R, Marotta R, Gasparini L. Lamin B1 protein is required for dendrite development in primary mouse cortical neurons. Mol Biol Cell 2016; 27:35-47. [PMID: 26510501 PMCID: PMC4694760 DOI: 10.1091/mbc.e15-05-0307] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Revised: 10/07/2015] [Accepted: 10/23/2015] [Indexed: 01/15/2023] Open
Abstract
Lamin B1, a key component of the nuclear lamina, plays an important role in brain development and function. A duplication of the human lamin B1 (LMNB1) gene has been linked to adult-onset autosomal dominant leukodystrophy, and mouse and human loss-of-function mutations in lamin B1 are susceptibility factors for neural tube defects. In the mouse, experimental ablation of endogenous lamin B1 (Lmnb1) severely impairs embryonic corticogenesis. Here we report that in primary mouse cortical neurons, LMNB1 overexpression reduces axonal outgrowth, whereas deficiency of endogenous Lmnb1 results in aberrant dendritic development. In the absence of Lmnb1, both the length and complexity of dendrites are reduced, and their growth is unresponsive to KCl stimulation. This defective dendritic outgrowth stems from impaired ERK signaling. In Lmnb1-null neurons, ERK is correctly phosphorylated, but phospho-ERK fails to translocate to the nucleus, possibly due to delocalization of nuclear pore complexes (NPCs) at the nuclear envelope. Taken together, these data highlight a previously unrecognized role of lamin B1 in dendrite development of mouse cortical neurons through regulation of nuclear shuttling of specific signaling molecules and NPC distribution.
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Affiliation(s)
- Caterina Giacomini
- Molecular Neurodegeneration Lab, Neuroscience and Brain Technologies Department, 16163 Genoa, Italy
| | - Sameehan Mahajani
- Molecular Neurodegeneration Lab, Neuroscience and Brain Technologies Department, 16163 Genoa, Italy
| | - Roberta Ruffilli
- Electron Microscopy Lab, Nanochemistry Department, Istituto Italiano di Tecnologia, 16163 Genoa, Italy
| | - Roberto Marotta
- Electron Microscopy Lab, Nanochemistry Department, Istituto Italiano di Tecnologia, 16163 Genoa, Italy
| | - Laura Gasparini
- Molecular Neurodegeneration Lab, Neuroscience and Brain Technologies Department, 16163 Genoa, Italy
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Camps J, Wangsa D, Falke M, Brown M, Case CM, Erdos MR, Ried T. Loss of lamin B1 results in prolongation of S phase and decondensation of chromosome territories. FASEB J 2014; 28:3423-34. [PMID: 24732130 PMCID: PMC4101663 DOI: 10.1096/fj.14-250456] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 04/07/2014] [Indexed: 01/04/2023]
Abstract
Nuclear lamin B1 (LMNB1) constitutes one of the major structural proteins in the lamina mesh. We silenced the expression of LMNB1 by RNA interference in the colon cancer cell line DLD-1 and showed a dramatic redistribution of H3K27me3 from the periphery to a more homogeneous nuclear dispersion. In addition, we observed telomere attrition and an increased frequency of micronuclei and nuclear blebs. By 3D-FISH analyses, we demonstrated that the volume and surface of chromosome territories were significantly larger in LMNB1-depleted cells, suggesting that LMNB1 is required to maintain chromatin condensation in interphase nuclei. These changes led to a prolonged S phase due to activation of Chk1. Finally, silencing of LMNB1 resulted in extensive changes in alternative splicing of multiple genes and in a higher number of enlarged nuclear speckles. Taken together, our results suggest a mechanistic role of the nuclear lamina in the organization of chromosome territories, maintenance of genome integrity and proper gene splicing.
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Affiliation(s)
- Jordi Camps
- Section of Cancer Genomics, Genetics Branch, National Cancer Institute, and
| | - Darawalee Wangsa
- Section of Cancer Genomics, Genetics Branch, National Cancer Institute, and
| | - Martin Falke
- Section of Cancer Genomics, Genetics Branch, National Cancer Institute, and
| | - Markus Brown
- Section of Cancer Genomics, Genetics Branch, National Cancer Institute, and
| | - Chanelle M Case
- Section of Cancer Genomics, Genetics Branch, National Cancer Institute, and
| | - Michael R Erdos
- Genome Technology Branch, National Human Genome Research Institute, U.S. National Institutes of Health, Bethesda, Maryland, USA
| | - Thomas Ried
- Section of Cancer Genomics, Genetics Branch, National Cancer Institute, and
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Kim Y, Sharov AA, McDole K, Cheng M, Hao H, Fan CM, Gaiano N, Ko MSH, Zheng Y. Mouse B-type lamins are required for proper organogenesis but not by embryonic stem cells. Science 2011; 334:1706-10. [PMID: 22116031 PMCID: PMC3306219 DOI: 10.1126/science.1211222] [Citation(s) in RCA: 197] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
B-type lamins, the major components of the nuclear lamina, are believed to be essential for cell proliferation and survival. We found that mouse embryonic stem cells (ESCs) do not need any lamins for self-renewal and pluripotency. Although genome-wide lamin-B binding profiles correlate with reduced gene expression, such binding is not directly required for gene silencing in ESCs or trophectoderm cells. However, B-type lamins are required for proper organogenesis. Defects in spindle orientation in neural progenitor cells and migration of neurons probably cause brain disorganizations found in lamin-B null mice. Thus, our studies not only disprove several prevailing views of lamin-Bs but also establish a foundation for redefining the function of the nuclear lamina in the context of tissue building and homeostasis.
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Affiliation(s)
- Youngjo Kim
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
| | - Alexei A. Sharov
- Developmental Genomics and Aging Section, Laboratory of Genetics, National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - Katie McDole
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Melody Cheng
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Haiping Hao
- Microarray Core Facility, Johns Hopkins University School of Medicine, Baltimore, MD 21209, USA
| | - Chen-Ming Fan
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Nicholas Gaiano
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Minoru S. H. Ko
- Developmental Genomics and Aging Section, Laboratory of Genetics, National Institute on Aging, NIH, Baltimore, MD 21224, USA
| | - Yixian Zheng
- Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
- Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
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Lin ST, Fu YH. miR-23 regulation of lamin B1 is crucial for oligodendrocyte development and myelination. Dis Model Mech 2009; 2:178-88. [PMID: 19259393 PMCID: PMC2650193 DOI: 10.1242/dmm.001065] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2008] [Accepted: 11/17/2008] [Indexed: 01/14/2023] Open
Abstract
Duplication of the gene encoding lamin B1 (LMNB1) with increased mRNA and protein levels has been shown to cause severe myelin loss in the brains of adult-onset autosomal dominant leukodystrophy patients. Similar to many neurodegenerative disorders, patients with adult-onset autosomal dominant leukodystrophy are phenotypically normal until adulthood and the defect is specific to the central nervous system despite the ubiquitous expression pattern of lamin B1. We set out to dissect the molecular mechanisms underlying this demyelinating phenotype. Increased lamin B1 expression results in disturbances of inner nuclear membrane proteins, chromatin organization and nuclear pore transport in vitro. It also leads to premature arrest of oligodendrocyte differentiation, which might be caused by reduced transcription of myelin genes and by mislocalization of myelin proteins. We identified the microRNA miR-23 as a negative regulator of lamin B1 that can ameliorate the consequences of excessive lamin B1 at the cellular level. Our results indicate that regulation of lamin B1 is important for myelin maintenance and that miR-23 contributes to this process, at least in part, by downregulating lamin B1, therefore establishing novel functions of lamin B1 and miR-23 in the regulation of oligodendroglia development and myelin formation in vitro.
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Affiliation(s)
- Shu-Ting Lin
- Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
| | - Ying-Hui Fu
- Department of Neurology, University of California San Francisco, San Francisco, CA 94158, USA
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Abstract
Interaction of lamins with chromatin and transcription factors regulate transcription. Oct-1 has previously been shown to colocalize partly with B-type lamins and is essential for transcriptional regulation of oxidative stress response genes. Using sequential extraction, co-immunoprecipitation (IP), fluorescence loss in photobleaching, and fluorescence resonance energy transfer, we confirm Oct-1-lamin B1 association at the nuclear periphery and show that this association is lost in Lmnb1(Delta/Delta) cells. We show that several Oct-1-dependent genes, including a subset involved in oxidative stress response, are dysregulated in Lmnb1(Delta/Delta) cells. Electrophoretic mobility shift assay and chromatin IP reveal that Oct-1 binds to the putative octamer-binding sequences of the dysregulated genes and that this activity is increased in cells lacking functional lamin B1. Like Oct1(-/-) cells, Lmnb1(Delta/Delta) cells have elevated levels of reactive oxygen species and are more susceptible to oxidative stress. Sequestration of Oct-1 at the nuclear periphery by lamin B1 may be a mechanism by which the nuclear envelope can regulate gene expression and contribute to the cellular response to stress, development, and aging.
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Affiliation(s)
- Ashraf N Malhas
- Department of Physics, Sir William Dunn School of Pathology, University of Oxford, Oxford, England, UK
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Sato A, Satake A, Hiramoto A, Okamatsu A, Nakama K, Kim HS, Wataya Y. Association of nuclear-intermediate filament lamin B1 with necrotic- and apoptotic-morphologies in cell death induced by 5-fluoro-2'-deoxyuridine. Nucleic Acids Symp Ser (Oxf) 2009; 53:293-4. [PMID: 19749376 DOI: 10.1093/nass/nrp147] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We report that anticancer 5-fluoro-2'-deoxyuridine (FUdR) shows cytotoxicity against mouse cancer cell line FM3A cells, using a progeny clone F28-7 and its variant F28-7-A. In this process, the cell-death morphology is different between F28-7 and F28-7-A cells, that is, necrosis in F28-7 but apoptosis in F28-7-A cells. Recently we have investigated the gene and protein expression profiles of necrosis and apoptosis induced by FUdR using transcriptomic and proteomic analyses. In the proteomic analysis of these cells before their exposure to FUdR, the nuclear inner-membrane protein lamin B1 is up-regulated in F28-7 but not in F28-7-A, suggesting that lamin B1 may possess a function to regulate the morphology of cell-death. A knockdown of lamin B1 expression in F28-7 cells has now been performed by use of the small interfering RNA technique, resulting in a decrease of the lamin B1-expression level down to the level in F28-7-A. Remarkably, the FUdR-induced death morphology of this knocked-down F28-7 was apoptosis, definitely different from the necrosis that occurs in the FUdR-treated original F28-7. Our present finding provides an interesting possibility that lamin-B1 may have an important role in regulating cell-death morphology.
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Affiliation(s)
- Akira Sato
- Faculty of Pharmaceutical Sciences, Okayama University, Okayama 700-8530, Japan.
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11
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Takagi M, Tahara K, Imamoto N. [Expanding role of the nucleocytoplasmic transport system during mitosis revealed by analyzing the mechanism to load Kid onto mitotic chromosomes]. Tanpakushitsu Kakusan Koso 2008; 53:1115-1124. [PMID: 18616139] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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12
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Tang CW, Maya-Mendoza A, Martin C, Zeng K, Chen S, Feret D, Wilson SA, Jackson DA. The integrity of a lamin-B1-dependent nucleoskeleton is a fundamental determinant of RNA synthesis in human cells. J Cell Sci 2008; 121:1014-24. [PMID: 18334554 DOI: 10.1242/jcs.020982] [Citation(s) in RCA: 87] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Spatial organisation of nuclear compartments is an important regulator of chromatin function, yet the molecular principles that maintain nuclear architecture remain ill-defined. We have used RNA interference to deplete key structural nuclear proteins, the nuclear lamins. In HeLa cells, we show that reduced expression of lamin B1, but not lamin A/C, severely inhibits RNA synthesis--first by RNA polymerase II and later by RNA polymerase I. Declining levels of transcription correlate with different morphological changes in major nuclear compartments, nucleoli and nuclear speckles. Ultimately, nuclear changes linked to the loss of synthetic activity result in expansion of the inter-chromatin domain and corresponding changes in the structure and spatial organisation of chromosome territories, which relocate towards the nuclear periphery. These results show that a lamin B1-containing nucleoskeleton is required to maintain RNA synthesis and that ongoing synthesis is a fundamental determinant of global nuclear architecture in mammalian cells.
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Affiliation(s)
- Chi W Tang
- Faculty of Life Sciences, University of Manchester, MIB, 131 Princess Street, Manchester, M1 7DN, UK
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13
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Abstract
Mutations in the nuclear envelope proteins lamins A and C cause a broad variety of human diseases, including Emery-Dreifuss muscular dystrophy, dilated cardiomyopathy, and Hutchinson-Gilford progeria syndrome. Cells lacking lamins A and C have reduced nuclear stiffness and increased nuclear fragility, leading to increased cell death under mechanical strain and suggesting a potential mechanism for disease. Here, we investigated the contribution of major lamin subtypes (lamins A, C, and B1) to nuclear mechanics by analyzing nuclear shape, nuclear dynamics over time, nuclear deformations under strain, and cell viability under prolonged mechanical stimulation in cells lacking both lamins A and C, cells lacking only lamin A (i.e. "lamin C-only" cells), cells lacking wild-type lamin B1, and wild-type cells. Lamin A/C-deficient cells exhibited increased numbers of misshapen nuclei and had severely reduced nuclear stiffness and decreased cell viability under strain. Lamin C-only cells had slightly abnormal nuclear shape and mildly reduced nuclear stiffness but no decrease in cell viability under strain. Interestingly, lamin B1-deficient cells exhibited normal nuclear mechanics despite having a significantly increased frequency of nuclear blebs. Our study indicates that lamins A and C are important contributors to the mechanical stiffness of nuclei, whereas lamin B1 contributes to nuclear integrity but not stiffness.
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Affiliation(s)
- Jan Lammerding
- Cardiovascular Division, Department of Medicine, and Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02139, USA.
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15
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Abstract
Mitotic spindle morphogenesis is a series of highly coordinated movements that lead to chromosome segregation and cytokinesis. We report that the intermediate filament protein lamin B, a component of the interphase nuclear lamina, functions in spindle assembly. Lamin B assembled into a matrix-like network in mitosis through a process that depended on the presence of the guanosine triphosphate-bound form of the small guanosine triphosphatase Ran. Depletion of lamin B resulted in defects in spindle assembly. Dominant negative mutant lamin B proteins that disrupt lamin B assembly in interphase nuclei also disrupted spindle assembly in mitosis. Furthermore, lamin B was essential for the formation of the mitotic matrix that tethers a number of spindle assembly factors. We propose that lamin B is a structural component of the long-sought-after spindle matrix that promotes microtubule assembly and organization in mitosis.
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Affiliation(s)
- Ming-Ying Tsai
- Department of Embryology, Carnegie Institution of Washington and Howard Hughes Medical Institute, Baltimore, MD 21218, USA
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Shumaker DK, Lopez-Soler RI, Adam SA, Herrmann H, Moir RD, Spann TP, Goldman RD. Functions and dysfunctions of the nuclear lamin Ig-fold domain in nuclear assembly, growth, and Emery-Dreifuss muscular dystrophy. Proc Natl Acad Sci U S A 2005; 102:15494-9. [PMID: 16227433 PMCID: PMC1255737 DOI: 10.1073/pnas.0507612102] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2005] [Indexed: 12/11/2022] Open
Abstract
The non-alpha-helical C terminus of Xenopus lamin B3 (LB3T) inhibits the polymerization of lamin B3 in vitro and prevents the assembly of nuclei in Xenopus egg interphase extracts. To more precisely define the functions of LB3T in nuclear assembly, we have expressed subdomains of LB3T and determined their effects on nuclear assembly in Xenopus extracts. The results demonstrate that the Ig-fold motif (LB3T-Ig) is sufficient to inhibit lamin polymerization in vitro. Addition of the LB3T-Ig to egg extracts before the introduction of chromatin prevents chromatin decondensation and the assembly of the lamina, membranes, and pore complexes comprising the nuclear envelope. When added to assembled nuclei, LB3T-Ig prevents the further incorporation of lamin B3 into the endogenous lamina and blocks nuclear growth. The introduction of a point mutation in LB3T-Ig (R454W; LB3T-IgRW), known to cause Emery-Dreifuss muscular dystrophy when present in lamin A, does not inhibit lamin polymerization, chromatin decondensation, or nuclear assembly and growth. These results shed light on the specific alterations in lamin functions attributable to a known muscular dystrophy mutation and provide an experimental framework for revealing the effects of other mutations causing a wide range of laminopathies.
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Affiliation(s)
- Dale K Shumaker
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, 303 East Chicago Avenue, Chicago, IL 60611, USA
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Abstract
In prophase cells, lamin B1 is the major component of the nuclear lamina, a filamentous network underlying the nucleoplasmic side of the nuclear membrane, whereas lamin A/C is dissociated from the scaffold. In vivo fluorescence microscopy studies have shown that, during the G2/M transition, the first gap in the nuclear envelope (NE) appears before lamin B1 disassembly and is caused by early spindle microtubules impinging on the NE. This result suggests that the mechanical tearing of the NE by microtubules plays a central role to the progression of mitosis. To investigate whether this microtubule-induced NE deformation is sufficient for NE breakdown, we assess the mechanical resilience of a reconstituted lamin B1 network. Quantitative rheological methods demonstrate that human lamin B1 filaments form stiff networks that can resist much greater deformations than those caused by microtubules impinging on the NE. Moreover, lamin B1 networks possess an elastic stiffness, which increases under tension, and an exceptional resilience against shear deformations. These results demonstrate that both mechanical tearing of the lamina and biochemical modification of lamin B1 filaments are required for NE breakdown.
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Affiliation(s)
- Porntula Panorchan
- Department of Chemical and Biomolecular Engineering, The Johns Hopkins University, Baltimore, Maryland 21218, USA
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