Lamin B1 overexpression alters chromatin organization and gene expression (mRNA-seq)
Ontology highlight
ABSTRACT:
ORGANISM(S): Homo sapiens
PROVIDER: GSE212107 | GEO | 2023/04/23
REPOSITORIES: GEO
Similar Datasets
Project description:Overexpression of Lamin B1 leads to the redistribution of H3K9me3 heterochromatin away from the nuclear periphery and into heterochromatic DNA foci within the nucleoplasm. These changes in chromatin organization correlate with misregulated gene expression (mRNA-sequencing), but do not correlate with altered H3K9me3 deposition across the genome (Cut&Run).
2023-04-23 | GSE212108 | GEO
Project description:Senescence is a stress responsive form of stable cell cycle exit. Senescent cells have a distinct gene expression profile, which is often accompanied by the spatial redistribution of heterochromatin into senescence-associated heterochromatic foci (SAHFs). Studying a key component of the nuclear lamina, lamin B1 (LMNB1), we report dynamic alterations in its genomic profile and their implications for SAHF formation and gene regulation during senescence. Genome-wide mapping reveals that LMNB1 is depleted during senescence, preferentially from the central regions of lamina-associated domains (LADs), which are enriched for H3K9me3. LMNB1 knockdown facilitates the spatial relocalization of perinuclear H3K9me3, thus promoting SAHF formation, which is inhibited by ectopic LMNB1 expression. Furthermore, despite the global reduction in LMNB1 protein levels, LMNB1 binding increases during senescence in a small subset of gene-rich regions where H3K27me3 also increases and gene expression becomes repressed. These results suggest that LMNB1 may contribute to senescence in at least two ways due to its uneven genomewide redistribution: firstly through the spatial re-organization of chromatin and, secondly, through gene repression. ChIP-seq for Lamin B1 in Growing and Ras Induced Senescence
2013-08-22 | E-GEOD-49341 | biostudies-arrayexpress
Project description:Senescence is a stress responsive form of stable cell cycle exit. Senescent cells have a distinct gene expression profile, which is often accompanied by the spatial redistribution of heterochromatin into senescence-associated heterochromatic foci (SAHFs). Studying a key component of the nuclear lamina, lamin B1 (LMNB1), we report dynamic alterations in its genomic profile and their implications for SAHF formation and gene regulation during senescence. Genome-wide mapping reveals that LMNB1 is depleted during senescence, preferentially from the central regions of lamina-associated domains (LADs), which are enriched for H3K9me3. LMNB1 knockdown facilitates the spatial relocalization of perinuclear H3K9me3, thus promoting SAHF formation, which is inhibited by ectopic LMNB1 expression. Furthermore, despite the global reduction in LMNB1 protein levels, LMNB1 binding increases during senescence in a small subset of gene-rich regions where H3K27me3 also increases and gene expression becomes repressed. These results suggest that LMNB1 may contribute to senescence in at least two ways due to its uneven genomewide redistribution: firstly through the spatial re-organization of chromatin and, secondly, through gene repression.
2013-08-22 | GSE49341 | GEO
Project description:Background: The eukaryotic genome is folded into higher-order conformation accompanied with constrained dynamics for coordinated genome functions. However, the molecular machinery underlying these hierarchically organized three-dimensional (3D) chromatin architecture and dynamics remains poorly understood. Results: Here by combining imaging and sequencing, we studied the role of lamin B1 in chromatin architecture and dynamics. We found that lamin B1 depletion leads to chromatin redistribution and decompaction. Consequently, lamina-associated domains (LADs) are detached from the nuclear periphery. The inter-chromosomal interactions and overlap between chromosome territories are increased. Moreover, Hi-C data revealed that lamin B1 is required for the integrity and segregation of chromatin compartments but not for the topologically associating domains (TADs). Using live cell single molecule tracking, we further proved that depletion of lamin B1 leads to increased chromatin dynamics, owing to chromatin decompaction and redistribution toward nucleoplasm. Conclusions: Taken together, our data suggest that lamin B1 and chromatin interactions at the nuclear periphery promote LAD maintenance, genomic compartmentalization into chromosome territories and A/B compartments and confine chromatin dynamics, supporting its crucial role in chromatin higher-order structure and chromatin dynamics.
2020-11-08 | GSE124409 | GEO
Project description:Gene positioning and regulation of nuclear architecture are thought to influence gene expression. Here, we show that in mouse olfactory neurons, silent olfactory receptor (OR) genes from different chromosomes converge in a small number of heterochromatic foci. These foci are OR-exclusive and form in a cell-type-specific and differentiation- dependent manner. The aggregation of OR genes is developmentally synchronous with the downregulation of Lamin b Receptor (LBR) and can be reversed by ectopic expression of LBR in mature olfactory neurons. LBR-induced reorganization of nuclear architecture and redistribution of OR loci results in misregulation of OR transcription and disruption of the targeting specificity of the olfactory neurons. Our observations are consistent with a model of spatial regulation of OR expression and provide evidence for the instructive role of nuclear architecture and compartmentalization in gene regulation and differentiation. A complex probe was made by array capture to label mouse olfactory receptor genes by DNA FISH; this microarray data verifies the composition of that probe. Probe was made by array capture and elution from a custom olfactory receptor genomic region tiling array. Probe was verified on a chr1-4 tiling array.
2012-08-30 | E-GEOD-38488 | biostudies-arrayexpress
Project description:Gene positioning and regulation of nuclear architecture are thought to influence gene expression. Here, we show that in mouse olfactory neurons, silent olfactory receptor (OR) genes from different chromosomes converge in a small number of heterochromatic foci. These foci are OR-exclusive and form in a cell-type-specific and differentiation- dependent manner. The aggregation of OR genes is developmentally synchronous with the downregulation of Lamin b Receptor (LBR) and can be reversed by ectopic expression of LBR in mature olfactory neurons. LBR-induced reorganization of nuclear architecture and redistribution of OR loci results in misregulation of OR transcription and disruption of the targeting specificity of the olfactory neurons. Our observations are consistent with a model of spatial regulation of OR expression and provide evidence for the instructive role of nuclear architecture and compartmentalization in gene regulation and differentiation. A complex probe was made by array capture to label mouse olfactory receptor genes by DNA FISH; this microarray data verifies the composition of that probe.
2012-08-30 | GSE38488 | GEO
Project description:Lamin B1 from OIS IMR90s We used ChIP-seq to examine the global binding of Lamin B1 in human IMR90 oncogene-induced senescence
2014-12-15 | E-GEOD-53331 | biostudies-arrayexpress
Project description:Lamins (A/C and B) are type V intermediate filaments and constitute the major cytoskeleton component of nuclei. They are assembled forming a filamentous meshwork that is mainly located between the inner nuclear membrane and the peripheral chromatin in where they form structural and conserved elements called lamin-associated domains (LADs) that cover around 40% of the mammalian genome. However, a small fraction of lamins are also located in the nucleoplasm although is still unclear if represents a fraction that is in transit towards the nuclear membrane, a reservoir for protein turnover or they have specific functions in nuclear organization6. Here we mapped genome-wide the localization of lamin B1 from an enriched euchromatin fraction. Our analysis show for the first time that lamin B1 can be also associated with active euchromatin forming domains of about half a megabase on average in size. These euchromatin lamin B1 domains (eLADs) are constituted by active and accessible euchromatin showed by RNAseq and ATACseq. Importantly, we have analyzed its behavior at the onset of the epithelial to mesenchymal transition (EMT), a cellular transformation process essential during development and reactivated in cancer cells. Our results suggest that eLADs are dynamic and functional during EMT. Finally, Hi-C data during this cellular transformation showed changes in the frequency of chromatin contacts around the TSS in genes enriched in lamin B1 before the generation of new regulatory elements in the mesenchymal state. Taken together, these results demonstrate that not only heterochromatin but euchromatin is organized into lamin domains as well. Moreover, these eLADs are dynamic, functional and essential for chromatin organization and gene regulation during the EMT.
2018-08-30 | GSE96033 | GEO
Project description:This is a small scale study of the phosphorylation state of human lamin B1 immunoprecipitated from control cells or cells treated with methyl methane sulphonate (MMS, acting as a DNA damage stressor agent)
2017-05-30 | PXD006459 | Pride
Project description:Nuclear lamin B1 constitutes one of the major structural proteins in the lamina mesh. We silenced the expression of lamin B1 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 an increased frequency of micronuclei and nuclear blebs. By 3D-FISH analyses, we demonstrate that the volume and surface of chromosome territories were significantly larger in LMNB1-depleted cells, suggesting that lamin B1 is required to maintain chromatin condensation in interphase nuclei. These changes led to a prolonged S-phase due to activation of Chk1 and telomere attrition. 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. This dataset includes the comparison of gene transcripts between cells with silenced lamin B1 and empty vector negative control transfected cells. Single cell clones were generated after transfection of DLD-1 cells with shRNA against LMNB1. Two different constructs were used. For clone number 2, three replicates of the the same clone were included in the analysis. The rest of the clones correspond to biological replicates. As control, we used three different cones transfected with an empty vector control as well as wild type cells.
2014-07-16 | E-GEOD-53546 | biostudies-arrayexpress