Molecular signatures of Emery–Dreifuss muscular dystrophy

2008 ◽  
Vol 36 (6) ◽  
pp. 1354-1358 ◽  
Author(s):  
Matthew A. Wheeler ◽  
Juliet A. Ellis
Keyword(s):  
Muscular Dystrophy ◽  
Dilated Cardiomyopathy ◽  
Molecular Mechanisms ◽  
Autosomal Dominant ◽  
Signalling Pathways ◽  
Lamin A ◽  
Degenerative Diseases ◽  
Hypertrophic Growth ◽  
Genes Encoding

Mutations in genes encoding the nuclear envelope proteins emerin and lamin A/C lead to a range of tissue-specific degenerative diseases. These include dilated cardiomyopathy, limb-girdle muscular dystrophy and X-linked and autosomal dominant EDMD (Emery–Dreifuss muscular dystrophy). The molecular mechanisms underlying these disorders are poorly understood; however, recent work using animal models has identified a number of signalling pathways that are altered in response to the deletion of either emerin or lamin A/C or expression of Lmna mutants found in patients with laminopathies. A distinguishing feature of patients with EDMD is the association of a dilated cardiomyopathy with conduction defects. In the present article, we describe several of the pathways altered in response to an EDMD phenotype, which are known to be key mediators of hypertrophic growth, and focus on a possible role of an emerin–β-catenin interaction in the pathogenesis of this disease.

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 A Review of the Molecular Mechanisms Underlying Cardiac Fibrosis and Atrial Fibrillation

2021 ◽  
Vol 10 (19) ◽  
pp. 4430
Author(s):  
Grażyna Sygitowicz ◽  
Agata Maciejak-Jastrzębska ◽  
Dariusz Sitkiewicz
Keyword(s):  
Atrial Fibrillation ◽  
Molecular Mechanisms ◽  
Cardiac Fibrosis ◽  
Transforming Growth Factor ◽  
Transforming Growth Factor Β1 ◽  
Signalling Pathways ◽  
Ang Ii ◽  
Atrial Fibrosis ◽  
Genes Encoding ◽  
Tgf Β1

The cellular and molecular mechanism involved in the pathogenesis of atrial fibrosis are highly complex. We have reviewed the literature that covers the effectors, signal transduction and physiopathogenesis concerning extracellular matrix (ECM) dysregulation and atrial fibrosis in atrial fibrillation (AF). At the molecular level: angiotensin II, transforming growth factor-β1, inflammation, and oxidative stress are particularly important for ECM dysregulation and atrial fibrotic remodelling in AF. We conclude that the Ang-II-MAPK and TGF-β1-Smad signalling pathways play a major, central role in regulating atrial fibrotic remodelling in AF. The above signalling pathways induce the expression of genes encoding profibrotic molecules (MMP, CTGF, TGF-β1). An important mechanism is also the generation of reactive oxygen species. This pathway induced by the interaction of Ang II with the AT2R receptor and the activation of NADPH oxidase. Additionally, the interplay between cardiac MMPs and their endogenous tissue inhibitors of MMPs, is thought to be critical in atrial ECM metabolism and fibrosis. We also review recent evidence about the role of changes in the miRNAs expression in AF pathophysiology and their potential as therapeutic targets. Furthermore, keeping the balance between miRNA molecules exerting anti-/profibrotic effects is of key importance for the control of atrial fibrosis in AF.

Abstract MP175: Disruption of the Genome Architecture at the PRRX1 Locus is Associated With the Pathogenesis of LMNA -related Dilated Cardiomyopathy

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Yuan Zhang ◽  
Mohamed Ameen ◽  
Isaac Perea Gil ◽  
Jennifer Arthur ◽  
Alexandra A Gavidia ◽  
...  
Keyword(s):  
Dilated Cardiomyopathy ◽  
Single Cell ◽  
Genome Organization ◽  
Molecular Mechanisms ◽  
Critical Role ◽  
Lamin A ◽  
Candidate Locus ◽  
Gene Encoding ◽  
Gene Dysregulation

Background: LMNA , a gene encoding A-type lamin proteins (abbreviated as lamin A), is one of the most frequently mutated genes in dilated cardiomyopathy (DCM). The molecular mechanisms underlying cardiomyocyte dysfunction in LMNA -related DCM remain elusive, translating to the lack of disease-specific therapies. Lamin A has been shown to play a critical role in genome organization via interactions with the chromatin at specific regions called lamina-associated domains (LADs). However, little is known about whether DCM-causing LMNA mutations rearrange the genome conformation and chromosome accessibility. The overarching goal of this study is to define the role of genome organization in LMNA -related DCM. Methods: LMNA -related DCM was modeled in vitro using cardiomyocytes derived from induced pluripotent stem cells (iPSC-CMs) from DCM patients carrying a frameshift mutation in the LMNA gene (c. 348_349insG; p. K117fs) and isogenic controls. We combined genome-wide single cell functional genomic and epigenomic mapping analyses to define the gene regulation and cis-regulatory interactions in isogenic iPSC-CMs. Results: Single-cell RNA-seq revealed global gene dysregulation in LMNA mutant compared to isogenic control iPSC-CMs. The homeodomain transcription factor PRRX1 was significantly upregulated in mutant cells. We showed that LAD integrity is disrupted at the PRRX1 locus in mutant iPSC-CMs. In agreement, DNA fluorescence in situ hybridization (FISH) revealed that the PRRX1 locus loses peripheral association and relocates towards the transcriptionally active nuclear interior in mutant iPSC-CMs. Correspondingly, single-cell assay for transposase accessible chromatin (ATAC)-seq showed increased chromatin co-accessibility at the PRRX1 locus, providing a plausible explanation for ectopic activation of PRRX1 in LMNA mutant iPSC-CMs. Conclusion: Our data suggest that LMNA haploinsufficiency disrupts the structure of LADs, leading to ectopic promoter interactions and altered gene expression in LMNA -related DCM iPSC-CMs. We identified PRRX1 as a promising candidate locus linking changes in LAD organization with gene dysregulation in LMNA -related DCM.

scholarly journals The role of Asprosin in patients with dilated cardiomyopathy

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Ming-Shien Wen ◽  
Chao-Yung Wang ◽  
Jih-Kai Yeh ◽  
Chun-Chi Chen ◽  
Ming-Lung Tsai ◽  
...  
Keyword(s):  
Dilated Cardiomyopathy ◽  
Mitochondrial Respiration ◽  
Cardiovascular Events ◽  
Molecular Mechanisms ◽  
Major Adverse Cardiovascular Events ◽  
Study Cohort ◽  
Protective Mechanisms ◽  
Mitochondrial Functions ◽  
And Function

Abstract Background Asprosin is a novel fasting glucogenic adipokine discovered in 2016. Asprosin induces rapid glucose releases from the liver. However, its molecular mechanisms and function are still unclear. Adaptation of energy substrates from fatty acid to glucose is recently considered a novel therapeutic target in heart failure treatment. We hypothesized that the asprosin is able to modulate cardiac mitochondrial functions and has important prognostic implications in dilated cardiomyopathy (DCM) patients. Methods We prospectively enrolled 50 patients (86% male, mean age 55 ± 13 years) with DCM and followed their 5-year major adverse cardiovascular events from 2012 to 2017. Comparing with healthy individuals, DCM patients had higher asprosin levels (191.2 versus 79.7 ng/mL, P < 0.01). Results During the 5-year follow-up in the study cohort, 16 (32.0%) patients experienced adverse cardiovascular events. Patients with lower asprosin levels (< 210 ng/mL) were associated with increased risks of adverse clinical outcomes with a hazard ratio of 7.94 (95% CI 1.88–33.50, P = 0.005) when compared patients with higher asprosin levels (≥ 210 ng/mL). Using cardiomyoblasts as a cellular model, we showed that asprosin prevented hypoxia-induced cell death and enhanced mitochondrial respiration and proton leak under hypoxia. Conclusions In patients with DCM, elevated plasma asprosin levels are associated with less adverse cardiovascular events in five years. The underlying protective mechanisms of asprosin may be linked to its functions relating to enhanced mitochondrial respiration under hypoxia.

scholarly journals Autosomal dominant dilated cardiomyopathy with atrioventricular block: a lamin A/C defect-related disease

2002 ◽  
Vol 39 (6) ◽  
pp. 981-990 ◽  
Author(s):  
Eloisa Arbustini ◽  
Andrea Pilotto ◽  
Alessandra Repetto ◽  
Maurizia Grasso ◽  
Andrea Negri ◽  
...  
Keyword(s):  
Dilated Cardiomyopathy ◽  
Atrioventricular Block ◽  
Autosomal Dominant ◽  
Lamin A ◽  
Related Disease

Mutations in the gene encoding lamin A/C cause autosomal dominant Emery-Dreifuss muscular dystrophy

10.1038/6799 ◽  
1999 ◽  
Vol 21 (3) ◽  
pp. 285-288 ◽  
Author(s):  
Gisèle Bonne ◽  
Marina Raffaele Di Barletta ◽  
Shaida Varnous ◽  
Henri-Marc Bécane ◽  
El-Hadi Hammouda ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Autosomal Dominant ◽  
Lamin A ◽  
Gene Encoding

Analysis of Genetic Variations of Lamin A/C Gene (LMNA) by Denaturing High-Performance Liquid Chromatography

2004 ◽  
Vol 9 (7) ◽  
pp. 625-628 ◽  
Author(s):  
Matthew R. G. Taylor ◽  
Misi L. Robinson ◽  
Luisa Mestroni
Keyword(s):  
High Performance Liquid Chromatography ◽  
Liquid Chromatography ◽  
Muscular Dystrophy ◽  
Dilated Cardiomyopathy ◽  
High Throughput ◽  
High Performance ◽  
Human Diseases ◽  
Lamin A ◽  
Nucleotide Polymorphisms ◽  
Lmna Gene

The human LMNA gene, when mutated, has been shown to cause at least 7 human diseases: dilated cardiomyopathy, Emery Dreifuss muscular dystrophy, limb girdle muscular dystrophy, familial partial lipodystrophy, Charcot Marie tooth disease type II, mandibuloacral dysplasia, and Hutchinson-Gilford Progeria (OMIM #176670). This article describes a high-throughput method for screening the human lamin A/C ( LMNA) gene for genetic mutations and sequence variation using denaturing high-performance liquid chromatography (DHPLC). In the present study, 76 patients with dilated cardiomyopathy were screened for mutations using DHPLC and sequence analysis. Abnormal elution profiles were identified and sequenced on an ABI 377 automatic sequencer. Heterozygous LMNA mutations were detected in 8% of the affected patients. In addition, a number of intronic and exonic single nucleotide polymorphisms were identified. LMNA mutations are clinically relevant in at least 6 human diseases. This study provides a protocol for high-throughput LMNA analysis applicable both in the research and in the clinical diagnostic setting.

scholarly journals A novel lamin A/C missense mutation in a family with autosomal dominant dilated cardiomyopathy with conduction abnormalities

2002 ◽  
Vol 39 ◽  
pp. 136 ◽  
Author(s):  
Ryuichiro Anan ◽  
Hideshi Niimura ◽  
Takeshi Sasaki ◽  
J.G. Seidman ◽  
Christine E. Seidman ◽  
...  
Keyword(s):  
Dilated Cardiomyopathy ◽  
Missense Mutation ◽  
Autosomal Dominant ◽  
Lamin A ◽  
Conduction Abnormalities

scholarly journals Lamin A/C–mediated neuromuscular junction defects in Emery-Dreifuss muscular dystrophy

2009 ◽  
Vol 184 (1) ◽  
pp. 31-44 ◽  
Author(s):  
Alexandre Méjat ◽  
Valérie Decostre ◽  
Juan Li ◽  
Laure Renou ◽  
Akanchha Kesari ◽  
...  
Keyword(s):  
Muscular Dystrophy ◽  
Mouse Models ◽  
Molecular Mechanisms ◽  
Neuromuscular Junctions ◽  
Wide Spectrum ◽  
Nuclear Architecture ◽  
Lamin A ◽  
Cellular Mechanisms ◽  
Activity Dependent ◽  
Filament Type

The LMNA gene encodes lamins A and C, two intermediate filament-type proteins that are important determinants of interphase nuclear architecture. Mutations in LMNA lead to a wide spectrum of human diseases including autosomal dominant Emery-Dreifuss muscular dystrophy (AD-EDMD), which affects skeletal and cardiac muscle. The cellular mechanisms by which mutations in LMNA cause disease have been elusive. Here, we demonstrate that defects in neuromuscular junctions (NMJs) are part of the disease mechanism in AD-EDMD. Two AD-EDMD mouse models show innervation defects including misexpression of electrical activity–dependent genes and altered epigenetic chromatin modifications. Synaptic nuclei are not properly recruited to the NMJ because of mislocalization of nuclear envelope components. AD-EDMD patients with LMNA mutations show the same cellular defects as the AD-EDMD mouse models. These results suggest that lamin A/C–mediated NMJ defects contribute to the AD-EDMD disease phenotype and provide insights into the cellular and molecular mechanisms for the muscle-specific phenotype of AD-EDMD.

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