scholarly journals Chromosome positioning is largely unaffected in lymphoblastoid cell lines containing emerin or A-type lamin mutations

2005 ◽  
Vol 33 (6) ◽  
pp. 1438-1440 ◽  
Author(s):  
K.J. Meaburn ◽  
N. Levy ◽  
D. Toniolo ◽  
J.M. Bridger
Keyword(s):  
Muscular Dystrophy ◽  
Cell Lines ◽  
Nuclear Periphery ◽  
Premature Aging ◽  
Lamin A ◽  
Lymphoblastoid Cell Lines ◽  
Human Chromosomes ◽  
Chromosome Location ◽  
Proliferating Cells ◽  
Tissue Degeneration

Gene-poor human chromosomes are reproducibly found at the nuclear periphery in proliferating cells. There are a number of inner nuclear envelope proteins that may have roles in chromosome location and anchorage, e.g. emerin and A-type lamins. In the last decade, a number of diseases associated with tissue degeneration and premature aging have been linked with mutations in lamin A or emerin. These are termed laminopathies, with mutations in emerin causing Emery–Dreifuss muscular dystrophy. Despite highly aberrant nuclear distributions of A-type lamins and emerin in lymphoblastoid cell lines derived from patients with emerin or lamin A mutations, little or no change in chromosome location was detected.

Nuclear envelope defects associated withLMNAmutations cause dilated cardiomyopathy and Emery-Dreifuss muscular dystrophy

2001 ◽  
Vol 114 (24) ◽  
pp. 4447-4457 ◽  
Author(s):  
Wahyu Hendrati Raharjo ◽  
Paul Enarson ◽  
Teresa Sullivan ◽  
Colin L. Stewart ◽  
Brian Burke
Keyword(s):  
Muscular Dystrophy ◽  
Dilated Cardiomyopathy ◽  
Hela Cells ◽  
Autosomal Dominant ◽  
Nuclear Periphery ◽  
Point Mutations ◽  
Molecular Organization ◽  
Structural Defects ◽  
Lamin A ◽  
Dominant Form

Nuclear lamin A and C alleles that are linked to three distinct human diseases have been expressed both in HeLa cells and in fibroblasts derived from Lmna null mice. Point mutations that cause dilated cardiomyopathy (L85R and N195K) and autosomal dominant Emery-Dreifuss muscular dystrophy (L530P) modify the assembly properties of lamins A and C and cause partial mislocalization of emerin, an inner nuclear membrane protein, in HeLa cells. At the same time, these mutant lamins interfere with the targeting and assembly of endogenous lamins and in this way may cause significant changes in the molecular organization of the nuclear periphery. By contrast, lamin A and C molecules harboring a point mutation (R482W), which gives rise to a dominant form of familial partial lipodystrophy, behave in a manner that is indistinguishable from wild-type lamins A and C, at least with respect to targeting and assembly within the nuclear lamina. Taken together, these results suggest that nuclear structural defects could contribute to the etiology of both dilated cardiomyopathy and autosomal dominant Emery-Dreifuss muscular dystrophy.

scholarly journals Deformation of the nucleus by TGFβ1 via the remodeling of nuclear envelope and histone isoforms

2022 ◽  
Vol 15 (1) ◽  
Author(s):  
Ya-Hui Chi ◽  
Wan-Ping Wang ◽  
Ming-Chun Hung ◽  
Gunn-Guang Liou ◽  
Jing-Ya Wang ◽  
...  
Keyword(s):  
Nuclear Envelope ◽  
Cell Lines ◽  
Nuclear Periphery ◽  
Nuclear Lamina ◽  
Lamin A ◽  
Nuclear Deformation ◽  
Smad Signaling ◽  
Lamin B1 ◽  
Compositional Changes ◽  
Nucleosomal Structure

AbstractThe cause of nuclear shape abnormalities which are often seen in pre-neoplastic and malignant tissues is not clear. In this study we report that deformation of the nucleus can be induced by TGFβ1 stimulation in several cell lines including Huh7. In our results, the upregulated histone H3.3 expression downstream of SMAD signaling contributed to TGFβ1-induced nuclear deformation, a process of which requires incorporation of the nuclear envelope (NE) proteins lamin B1 and SUN1. During this process, the NE constitutively ruptured and reformed. Contrast to lamin B1 which was relatively stationary around the nucleus, the upregulated lamin A was highly mobile, clustering at the nuclear periphery and reintegrating into the nucleoplasm. The chromatin regions that lost NE coverage formed a supra-nucleosomal structure characterized by elevated histone H3K27me3 and histone H1, the formation of which depended on the presence of lamin A. These results provide evidence that shape of the nucleus can be modulated through TGFβ1-induced compositional changes in the chromatin and nuclear lamina.

scholarly journals Valproic acid is protective in cellular and worm models of oculopharyngeal muscular dystrophy

Neurology ◽  
2018 ◽  
Vol 91 (6) ◽  
pp. e551-e561 ◽  
Author(s):  
Aida Abu-Baker ◽  
Alex Parker ◽  
Siriram Ramalingam ◽  
Janet Laganiere ◽  
Bernard Brais ◽  
...  
Keyword(s):  
Valproic Acid ◽  
Muscular Dystrophy ◽  
Cell Lines ◽  
Cell Model ◽  
C2c12 Cell ◽  
Oculopharyngeal Muscular Dystrophy ◽  
Lymphoblastoid Cell Lines ◽  
Protective Effects ◽  
C Elegans ◽  
Proliferation And Differentiation

ObjectiveTo explore valproic acid (VPA) as a potentially beneficial drug in cellular and worm models of oculopharyngeal muscular dystrophy (OPMD).MethodsUsing a combination of live cell imaging and biochemical measures, we evaluated the potential protective effect of VPA in a stable C2C12 muscle cell model of OPMD, in lymphoblastoid cell lines derived from patients with OPMD and in a transgenic Caenorhabditis elegans OPMD model expressing human mutant PABPN1.ResultsWe demonstrated that VPA protects against the toxicity of mutant PABPN1. Of note, we found that VPA confers its long-term protective effects on C2C12 cell survival, proliferation, and differentiation by increasing the acetylated level of histones. Furthermore, VPA enhances the level of histone acetylation in lymphoblastoid cell lines derived from patients with OPMD. Moreover, treatment of nematodes with moderate concentrations of VPA significantly improved the motility of the PABPN-13 Alanines worms.ConclusionsOur results suggest that VPA helps to counteract OPMD-related phenotypes in the cellular and C elegans disease models.

scholarly journals Phosphorylated Lamin A/C in the nuclear interior binds active enhancers associated with abnormal transcription in progeria

2019 ◽  
Author(s):  
Kohta Ikegami ◽  
Stefano Secchia ◽  
Omar Almakki ◽  
Jason D. Lieb ◽  
Ivan P. Moskowitz
Keyword(s):  
Binding Sites ◽  
Human Fibroblasts ◽  
Nuclear Periphery ◽  
Transcriptional Activator ◽  
Premature Aging ◽  
Lamin A ◽  
List Type ◽  
Enhancer Activity ◽  
Nuclear Interior ◽  
Specific Subset

ABSTRACTLMNA encodes nuclear lamin A/C that tethers lamina-associated heterochromatin domains (LADs) to the nuclear periphery. Point mutations in LMNA cause degenerative disorders including the premature aging disorder Hutchinson-Gilford progeria, but the mechanisms are unknown. We report that Ser22-phosphorylated Lamin A/C (pS22-Lamin A/C) was localized to the interior of the nucleus in human fibroblasts throughout the cell cycle. pS22-Lamin A/C interacted with a specific subset of putative active enhancers, not LADs, primarily at locations co-bound by the transcriptional activator c-Jun. In progeria-patient fibroblasts, a subset of pS22-Lamin A/C-binding sites were lost whereas new pS22-Lamin A/C-binding sites emerged in normally quiescent loci. These new pS22-Lamin A/C-binding sites displayed increased histone acetylation and c-Jun binding, implying increased enhancer activity. The genes near these new binding sites, implicated in clinical components of progeria including carotid artery diseases, hypertension, and cardiomegaly, were upregulated in progeria. These results suggest that Lamin A/C regulates gene expression by direct enhancer binding in the nuclear interior. Disruption of the gene regulatory rather than LAD function of Lamin A/C presents a novel mechanism for disorders caused by LMNA mutations including progeria.HIGHLIGHTSpS22-Lamin A/C is present in the nuclear interior throughout interphase.pS22-Lamin A/C associates with active enhancers, not lamina-associated domains.pS22-Lamin A/C-genomic binding sites are co-bound by the transcriptional activator c-Jun.New pS22-Lamin A/C binding in progeria accompanies upregulation of disease-related genes.

Responses to extracellular ATP of lymphoblastoid cell lines from Duchenne muscular dystrophy patients

1994 ◽  
Vol 267 (4) ◽  
pp. C886-C892 ◽  
Author(s):  
D. Ferrari ◽  
M. Munerati ◽  
L. Melchiorri ◽  
S. Hanau ◽  
F. di Virgilio ◽  
...  
Keyword(s):  
Duchenne Muscular Dystrophy ◽  
Muscular Dystrophy ◽  
Cell Lines ◽  
Ion Homeostasis ◽  
Normal Subjects ◽  
Extracellular Atp ◽  
Striking Difference ◽  
Lymphoblastoid Cell Lines ◽  
Lymphoblastoid Cells ◽  
Pyrimidine Nucleotides

We have observed a striking difference in the response to extracellular ATP in lymphoblastoid cell lines established from Duchenne muscular dystrophy patients and normal subjects. Duchenne muscular dystrophy cells stimulated by extracellular ATP underwent a large increase in the cytoplasmic Ca2+ concentration ([Ca2+]i) and plasma membrane depolarization, while normal cell lines were little or not at all responsive. These changes in intracellular ion homeostasis were due to activation of an ATP-gated membrane channel permeable to Na+ and Ca2+, with little or no contribution of Ca2+ release from intracellular stores. The channel was selectively activated by ATP, since other purine/pyrimidine nucleotides were ineffective, and it was inhibited by pretreatment with oxidized ATP, a compound previously reported to irreversibly inhibit P2 purinergic receptors. In the presence of extracellular ATP, lymphoblastoid cells established from Duchenne muscular dystrophy patients, but not from healthy controls, underwent rounding and swelling and eventually lysed. The results of this study suggest that lymphoblastoid cells isolated from Duchenne muscular dystrophy patients are eminently sensitive to stimulation by extracellular ATP.

scholarly journals Proliferation-dependent positioning of individual centromeres in the interphase nucleus of human lymphoblastoid cell lines

2015 ◽  
Vol 26 (13) ◽  
pp. 2550-2560 ◽  
Author(s):  
Jean Ollion ◽  
François Loll ◽  
Julien Cochennec ◽  
Thomas Boudier ◽  
Christophe Escudé
Keyword(s):  
Cell Lines ◽  
Nuclear Organization ◽  
Lymphoblastoid Cell Lines ◽  
Nuclear Positioning ◽  
Proliferating Cells ◽  
Human Lymphoblastoid Cell ◽  
Human Lymphoblastoid Cell Lines ◽  
High Throughput Imaging ◽  
Differential Attraction

The cell nucleus is a highly organized structure and plays an important role in gene regulation. Understanding the mechanisms that sustain this organization is therefore essential for understanding genome function. Centromeric regions (CRs) of chromosomes have been known for years to adopt specific nuclear positioning patterns, but the significance of this observation is not yet completely understood. Here, using a combination of fluorescence in situ hybridization and immunochemistry on fixed human cells and high-throughput imaging, we directly and quantitatively investigated the nuclear positioning of specific human CRs. We observe differential attraction of individual CRs toward both the nuclear border and the nucleoli, the former being enhanced in nonproliferating cells and the latter being enhanced in proliferating cells. Similar positioning patterns are observed in two different lymphoblastoid cell lines. Moreover, the positioning of CRs differs from that of noncentromeric regions, and CRs display specific orientations within chromosome territories. These results suggest the existence of not-yet-characterized mechanisms that drive the nuclear positioning of CRs and therefore pave the way toward a better understanding of how CRs affect nuclear organization.

MicroRNAs in Human Lymphoblastoid Cell Lines

2012 ◽  
Vol 22 (3) ◽  
pp. 189-196 ◽  
Author(s):  
Sung-Mi Shim ◽  
Hye-Young Nam ◽  
Jae-Eun Lee ◽  
Jun-Woo Kim ◽  
Bok-Ghee Han ◽  
...  
Keyword(s):  
Cell Lines ◽  
Lymphoblastoid Cell Lines ◽  
Human Lymphoblastoid Cell ◽  
Human Lymphoblastoid Cell Lines

scholarly journals Emerin Represses STAT3 Signaling through Nuclear Membrane-Based Spatial Control

2021 ◽  
Vol 22 (13) ◽  
pp. 6669
Author(s):  
Byongsun Lee ◽  
Seungjae Lee ◽  
Younggwang Lee ◽  
Yongjin Park ◽  
Jaekyung Shim
Keyword(s):  
Muscular Dystrophy ◽  
Nuclear Membrane ◽  
Target Genes ◽  
Janus Kinase ◽  
C2c12 Cells ◽  
Specific Gene ◽  
Lamin A ◽  
Stat3 Signaling ◽  
Exact Function ◽  
Muscle Homeostasis

Emerin is the inner nuclear membrane protein involved in maintaining the mechanical integrity of the nuclear membrane. Mutations in EMD encoding emerin cause Emery-Dreifuss muscular dystrophy (EDMD). There has been accumulating evidence that emerin regulation of specific gene expression is associated with this disease, but the exact function of emerin has still less revealing. Here, we have shown that emerin downregulates signal transducers and activators of transcription 3 (STAT3) signaling, activated exclusively by Janus-kinase (JAK). Deletion mutation experiments showed that the lamin-binding domain of emerin is essential for the inhibition of STAT3 signaling. Emerin interacted directly and co-localized with STAT3 in the nuclear membrane. Emerin knockdown induced STAT3 target genes Bcl2 and Survivin to increase cell survival signals and suppress hydrogen peroxide-induced cell death in HeLa cells. Specifically, downregulation of BAF or lamin A/C increases STAT3 signaling, suggesting that correct-localized emerin by assembling with BAF and lamin A/C acts as an intrinsic inhibitor against STAT3 signaling. In C2C12 cells, emerin knockdown induced STAT3 target gene, Pax7, and activated abnormal myoblast proliferation associated with muscle wasting in skeletal muscle homeostasis. Our results indicate that emerin downregulates STAT3 signaling by inducing retention of STAT3 and delaying STAT3 signaling in the nuclear membrane. This mechanism provides clues to the etiology of emerin-related muscular dystrophy and could be a new therapeutic target for treatment.

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