Genomic Reorganization of Lamin-Associated Domains in Cardiac Myocytes is Associated with Differential Gene Expression and DNA Methylation in Human Dilated Cardiomyopathy [RNA-Seq]
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ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE120836 | GEO | 2019/03/12
REPOSITORIES: GEO
Similar Datasets
Project description:Mutations in the LMNA gene causes set of disorders collectively referred to as laminopathies that include dilated cardiomyopathy. Lamin A/C proteins a components of nuclear lamina forms distinct nuclear domains called lamina associated domains (LADs). The roles of LADs in DCM is not known. To identify LADs and characterize their associations with CpG methylation and gene expression in human cardiac myocytes isolated from patients with DCM and controls we performed Chromatin immunoprecipitation-sequencing (ChIP-Seq), reduced representative bisulfite sequencing (RRBS), and RNA-sequencing (RNA-Seq) in 5 control and 5 DCM hearts with defined pathogenic variants in the LMNA gene. LADs are redistributed in DCM, are associated with CpG methylation and suppressed transcription, contributing to the pathogenesis of DCM in laminopathies.
2019-03-12 | GSE120837 | GEO
Project description:Mutations in LMNA, encoding Lamin A/C, lead to a variety of diseases known as laminopathies that include dilated cardiomyopathy (DCM). The role of epigenetic mechanisms. such as DNA methylation, has not been thoroughly investigated. Furthermore, the impact of patient-specific LMNA mutations on DNA methylation is unknown. To explore the role of DNA methylation in the context of unique LMNA mutations, we performed reduced representation bisulfite sequencing (RRBS) on ten pairs of fibroblasts and their induced pluripotent stem cell (iPSC) derivatives from two families with DCM due to distinct LMNA mutations. Family-specific differentially methylated regions (DMRs) were identified by comparing the DNA methylation landscape of patient and control samples. Fibroblast DMRs were found to enrich for distal regulatory features and transcriptionally repressed chromatin and to associate with genes related to phenotypes found in laminopathies. These DMRs, in combination with transcriptome-wide expression data and Lamina-associated domain (LAD) organization, revealed the presence of inter-family epimutation hotspots near differentially expressed genes, most of which were located near redistributed LADs. Comparison of DMRs found in fibroblasts and iPSCs identified regions where epimutations were persistent across both cell types. Finally, a network of disease-associated genes dysregulated in LMNA mutated cells was uncovered, potentially due to aberrant methylation changes. In conclusion, the use of in vitro culture models of patient-derived cells and differential methylation analysis enabled the identification of epimutation hotspots and dysregulated genes, consistent with a Lamin A/C mutation-specific epigenetic disease mechanism that arose in somatic and early-developmental cell stages.
2021-07-20 | GSE164365 | GEO
Project description:• Mutations in the LMNA gene encoding Lamin A and C (Lamin A/C), major components of the nuclear lamina, cause laminopathies including dilated cardiomyopathy (DCM), but the underlying molecular mechanisms have not been fully elucidated. Here, by leveraging single-cell RNA-seq, ATAC-seq, protein array, and electron microscopy analysis, we show that insufficient structural maturation of cardiomyocytes owing to trapping of transcription factor TEAD1 by mutant Lamin A/C at the nuclear membrane underlies the pathogenesis of Q353R- LMNA-related DCM. Inhibition of the Hippo pathway rescued the dysregulation of cardiac developmental genes by TEAD1 in LMNA-mutant cardiomyocytes. Single-cell RNA-seq of cardiac tissues from DCM patients with the LMNA mutation confirmed the dysregulated expression of TEAD1 target genes. Our results propose an intervention for transcriptional dysregulation as a potential treatment of LMNA-related DCM.
2023-03-06 | GSE190977 | GEO
Project description:Using ATAC seq analysis, we showed that the MEFs with a knockout of Lmna gene (i.e., missing the lamin A/C nuclear scaffolding protein) (Lmna-/- MEFs) display a striking change in chromatin accessibility landscape (peak signals that are both up and down), both within and outside lamina-associated domains (LADs); moreover, there was a clear overrepresentation of peaks with a gain in chromatin accessibility (within and outside LADs) in the Lmna-/- MEFs, and within LADs compared to outside LADs.
2022-08-31 | GSE186677 | GEO
Project description:The nuclear lamina interacts with the genome through megabase-size lamina-associated domains (LADs). LADs have been identified in proximity labeling assays and recently by chromatin immunoprecipitation-sequencing (ChIP-seq) of A- and B-type lamins. LADs localize mainly to the nuclear periphery, they are gene-poor and largely heterochromatic. Here, we show that the mode of chromatin fragmentation for ChIP, namely either bath sonication (used to date for ChIP of nuclear lamins) or digestion with micrococcal nuclease (MNase) leads to the discovery of distinct sets of lamin-interacting domains (which we refer to as LiDs) with distinct gene content, histone composition enrichment and relationship to lamin B1-interacting domains. We find that total genome coverage by lamin A/C ('LMNA') LiDs identified in sonicated or MNase-digested chromatin is similar (~730 megabases). Over half of these domains, however, are uniquely detected in sonicated or MNase-digested chromatin. Whereas sonication-specific LMNA LiDs are gene-poor and devoid of a broad panel of histone modifications, MNase-specific LMNA LiDs are of higher gene density and are enriched in H3K9me3, H3K27me3 and in histone variant H2A.Z. Analysis of published LMNB1 LADs and of LMNB1 LiDs identified by ChIP-seq further shows that LMNA can associate with 'open' chromatin domains displaying euchromatin features which are not associated with LMNB1. The differential genetic and epigenetic properties of lamin-interacting chromatin domains indicate the existence of distinct LiD populations identifiable in different chromatin contexts, including nuclease-accessible 'open' regions presumably localized in the nuclear interior.
2015-03-24 | GSE57149 | GEO
Project description:The nuclear lamina is a proteinaceous network of filaments that provide both structural and gene regulatory functions by tethering proteins and large domains of DNA, so-called lamin associated domains (LADs), to the periphery of the nucleus. LADs are a large fraction of the mammalian genome that are repressed, in part, by their association to the nuclear periphery. The genesis and maintenance of LADs is poorly understood as are the proteins that participate in these functions. In an effort to identify proteins that reside at the nuclear periphery and potentially interact with LADs, we have taken a two-pronged approach. First, we have undertaken an interactome analysis of the inner nuclear membrane bound LAP2β to further characterize the nuclear lamina proteome. To accomplish this, we have leveraged the BioID system, which previously has been successfully used to characterize the nuclear lamina proteome. Second, we have established a system to identify proteins that bind to LADs by developing a chromatin directed BioID system. We combined the BioID system with the m6A-tracer system which binds to LADs in live cells to identify LAD proximal and nuclear lamina proteins. In combining these datasets, we have further characterized the protein network at the nuclear lamina as well as identified putative LAD proximal proteins. Our analysis identifies many heterochromatin related proteins related to H3K9 methylation processes as well as many proteins related to cell cycle regulation identifying important proteins essential for LAD function.
2021-03-09 | PXD012943 | Pride
Project description:Lamins are type V intermediate filament proteins underlying the inner nuclear membrane which provide structural rigidity to the nucleus, tether the chromosomes and maintain nuclear homeostasis. Studies have identified developmentally regulated regions of the genome that are dynamically associated with the nuclear lamina. A large number of mutations in LMNA gene encoding lamin A/C results in a wide array of human diseases, collectively termed as laminopathies. Dilated Cardiomyopathy (DCM) is one such cardiovascular disease which is associated with systolic dysfunction of left or both ventricles leading to cardiac arrhythmia culminating into myocardial infarction. In this work, we have unravelled the gene expression by RNA Sequencing analysis in mouse myoblast cell line in the context of the missense mutation LMNA 289A>G (Lys97Glu) that is found in DCM afflicted patients with severe symptoms.
2022-06-26 | GSE206759 | GEO
Project description:Lamin A/C proteins, encoded by the LMNA gene, are intermediate filament proteins of the nuclear lamina, and predominantly expressed in differentiated cells including cardiomyocytes. Mutations in LMNA are associated with laminopathies, congenital diseases affecting muscle and homeostasis. One of the laminopathies associated with a missense mutation (N195K) in the A-type lamins results in dilated cardiomyopathy (DCM) with arrhythmias and sudden death. However it is unknown how the mutation in this LMNA gene contributes to the mechanism of arrhythmia and sudden death. To investigate this a mouse line expressing the Lmna-N195K (LmnaN195K/N195K) was used. Mutant mice demonstrated reduced fractional shortening, LV mass, wall thickness and dilated cardiomyopathy by echocardiography at 6 weeks consistent with human DCM, and died at an early age (6-7 weeks). Comparative cDNA microarray analysis from LmnaN195K/N195K and the wild type (WT) control ventricles at 6 weeks age revealed significant alterations in the expression of ion channels, transporter proteins, caveolins and associated proteins such as MAP kinases. Transmission electron microscopy analysis showed structural alterations of the ventricular myocytes with increase in number of caveolae. Quantitative Western blot analysis confirmed reduced expression for Cavβ (2 fold) subunits of the L-type Ca2+ channel. In contrast the expression levels of Cav3 (2.5 fold) was significantly increased. To investigate the functional impact of Lmna N195K on the ICa,L, we transiently expressed either the WT LMNA+GFP, Lmna N195K+GFP or GFP (control) in isolated neonatal mouse ventricular myocytes and performed whole cell patch clamp analysis. Transient expression of Lmna N195K significantly reduced (58 %) peak ICa,L (-6.0 ± 2 pA/pF, n=9) compared to GFP control (-14 ± 2 pA/pF, n=8). Expression of WT LMNA did not affect the ICa,L (-14.2 ± 2.5 pA/pF, n=8) compared to control. Conclusion: We conclude that Lmna N195K mutation results in reduced expression of ion channels and scaffolding proteins in the left ventricle with a significant reduction in peak ICa,L in ventricular myocytes and these may contribute to the mechanism of arrhythmia and dilated cardiomyopathy. 6 samples
2012-05-31 | E-GEOD-36502 | biostudies-arrayexpress
Project description:Interactions between the nuclear lamina (NL) and chromatin are thought to occur through large lamin association domains (LADs) and correlate with gene repression in these domains. We show that binding of lamin A/C (LMNA) to promoters occurs on discrete domains that are associated with distinct transcriptional outputs. Chromatin immunoprecipitation identifies thousands of LMNA-bound promoters, primarily linked to signaling functions. LMNA often occupies narrow domains on promoters, yet LMNA-bound promoters are often contiguous. LMNA-bound genes are overall repressed, but repression correlates with co-enrichment in repressive histone marks rather than LMNA occupancy per se. Genes marked by LMNA and H3K4me3 escape LMNA-associated repression in the absence of repressive histone marks. Positioning of LMNA on promoters relative to the TSS correlates with distinct transcriptional outputs: whereas upstream-distal binding can be transcriptionally permissive, TSS occupancy is associated with promoter inactivity. Perturbation in NL organization causes reorganization of lamin promoter occupancy and uncouples LMNA binding from promoter inactivity. Our results show the existence of many spatially restricted LMNA binding events on promoter regions, with distinct position-dependent transcriptional outputs. Total RNA obtained from ASCs and ASCs depleted of LMNA (LMNA-KD) and processed for microarray hybridization.
2013-07-14 | E-GEOD-42523 | biostudies-arrayexpress
Project description:A large fraction of the mammalian genome is organized into inactive chromosomal domains associated with the nuclear lamina. Using genomic repositioning assays we show that Lamina associated domains (LADs), spanning the developmentally regulated IgH and Cyp3a loci, contain transportable DNA regions that associate chromatin with the nuclear lamina and repress gene activity in fibroblasts. We characterized DNA regions within LADs that are functionally capable of positioning chromatin domains at the inner nuclear membrane (INM) lamina. We mapped and characterized the IgH and other LADs in murine fibroblasts. We show that these murine LADs have a unique chromatin structure with discrete boundaries. We demonstrate DNA regions within LADs that are capable of directing the association of chromatin domains with the INM-lamina as well as the silencing of a co-integrated reporter gene.
2012-02-24 | E-GEOD-36048 | biostudies-arrayexpress