Lamin A/C ablation in pancreatic acinar cells
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE97396 | GEO | 2017/11/30
SECONDARY ACCESSION(S): PRJNA381630
REPOSITORIES: GEO
Similar Datasets
Project description:The A-type lamins (lamin A/C), encoded by the Lmna gene, are important structural components of the nuclear lamina. Lmna mutations lead to degenerative disorders, including the premature aging disease Hutchinson-Gilford progeria syndrome (HGPS). In addition, altered lamin A/C expression is found in various cancers. Reports indicate that lamin A/C plays a role in DNA double strand break repair, but a role in DNA base excision repair (BER) has not been described. We provide evidence for reduced BER efficiency in lamin A/C-depleted cells. The mechanism involves impairment of the APE1 and POLβ enzyme activities in BER. Also, Lmna null mouse fibroblasts displayed reduced expression of several core BER enzymes (PARP1, LIG3, and POLβ). Moreover, the robustness of APE1 and POLβ activities and the rate of BER were enhanced by lamin A/C-augmented poly(ADP-ribose) polymer formation (PARylation). Finally, we report that HGPS fibroblasts are defective in BER. Collectively, our results provide novel insights into the functional interplay between the nuclear lamina and cellular defenses against oxidative DNA damage, with implications for human cancer and aging.
2019-10-02 | GSE120389 | GEO
Project description:The A-type lamins (lamin A/C), encoded by the Lmna gene, are important structural components of the nuclear lamina. Lmna mutations lead to degenerative disorders, including the premature aging disease Hutchinson-Gilford progeria syndrome (HGPS). In addition, altered lamin A/C expression is found in various cancers. Reports indicate that lamin A/C plays a role in DNA double strand break repair, but a role in DNA base excision repair (BER) has not been described. We provide evidence for reduced BER efficiency in lamin A/C-depleted cells. The mechanism involves impairment of the APE1 and POLβ enzyme activities in BER. Also, Lmna null mouse fibroblasts displayed reduced expression of several core BER enzymes (PARP1, LIG3, and POLβ). Moreover, the robustness of APE1 and POLβ activities and the rate of BER were enhanced by lamin A/C-augmented poly(ADP-ribose) polymer formation (PARylation). Finally, we report that HGPS fibroblasts are defective in BER. Collectively, our results provide novel insights into the functional interplay between the nuclear lamina and cellular defenses against oxidative DNA damage, with implications for human cancer and aging.
2020-09-30 | GSE124465 | GEO
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: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. ChIPs were done from cultured untreated and LMNA-downregulated adipose stem cell (ASC) chromatin. MeDIPs were done from LMNA-downregulated ASCs. ChIP and MeDIP DNA was hybridized onto the aforementioned HG-18 Nimbegen promoter arrays.
2013-07-14 | E-GEOD-42522 | biostudies-arrayexpress
Project description:Background: Lamins A/C (encoded by the LMNA gene) can lead to dilated cardiomyopathy (DCM). Objectives: This study sought to undertake proteomic analysis of myocardial tissue to explore the postgenomic phenotype of end-stage lamin heart disease. Methods: Consecutive patients with end-stage lamin heart disease (LMNA-group, n=7) and ischaemic DCM (ICM-group, n=7) undergoing heart transplantation were enrolled. Samples were obtained from left atrium(LA), left ventricle(LV), right atrium(RA), right ventricle(RV) and interventricular septum(IVS). Liquid chromatography combined with mass-spectrometry was used for protein quantification. We compared protein concentrations in cardiac samples between LMNA and ICM groups. Proteins were considered differentially abundant if the quantitative difference was 1.5-fold and corrected p-value <0.05 at a false discovery rate of 0.01. Gene ontology(GO) enrichment analysis explored the related biological processes. Results: 4,247 proteins were identified in LMNA and ICM samples, of which 633 were differentially abundant in LA, 39 in LV, 181 in RA, 52 in RV, and 85 in IVS. Abundance of lamin A/C was reduced but lamin B (LMNB) increased in LMNA LA/RA tissue compared to ICM, but not in LV/RV. Transthyretin was more abundant in the LV/RV of LMNA compared to ICM while sarcomeric proteins such as titin and cardiac myosin heavy chain were generally reduced in RA/LA of LMNA. Protein expression profiling and GO enrichment analysis revealed sarcopenia, extracellular matrix(ECM) remodeling, deficient myocardial energetics, redox imbalances, and abnormal calcium handling in LMNA samples. Conclusion: Lamin heart disease is a biventricular and biatrial disease, characterized by sarcopenia, aberrant metabolism, and ECM remodeling. LMNB and transthyretin were unexpectedly abundant in the atria and ventricles respectively of patients with end-stage lamin heart disease potentially hinting to the possibility of compensatory responses.
2024-01-26 | PXD040488 | Pride
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.
2013-07-14 | GSE42523 | 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: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.
2013-07-14 | GSE42522 | GEO
Project description:Lamin A/C are nuclear intermediate filament proteins that form a proteinaceous meshwork called lamina beneath the inner nuclear membrane. Mutations in the LMNA gene encoding lamin A/C cause a heterogenous group of inherited degenerative diseases known as laminopathies. Previous studies have revealed altered cell signaling pathways in lamin mutant patient cells, but little is known about the fate of mutant lamin A/C within the cells. Here, we analyzed the turnover of lamin A/C in cells derived from a dilated cardiomyopathy patient with a heterozygous p.S143P mutation in LMNA. We found that transcriptional activation and mRNA levels of LMNA are increased in the primary patient fibroblasts, but that the lamin A/C protein levels remain equal in control and patient cells because of a meticulous interplay between autophagy and the ubiquitin-proteasome system (UPS). Both endogenous and ectopic expression of p.S143P lamin A/C cause significantly reduced activity of UPS and accumulation of K48-ubiquitin chains in the nucleus. Furthermore, K48-ubiquitinated lamin A/C is degraded by compensatory enhanced autophagy, as shown by increased autophagosome formation and binding of lamin A/C to microtubule-associated protein 1A/1B-light chain 3. Finally, a chaperone 4-PBA augmented protein degradation by restoring UPS activity as well as autophagy in the patient cells. In summary, our results suggest that the p.S143P mutant lamin A/C has overloading and deleterious effects on protein degradation machinery and pharmacological interventions with compounds enhancing protein degradation may be beneficial for cell homeostasis.
2022-09-07 | PXD033937 | Pride
Project description:The main scientific objective of the project was to investigate whether Lamin A/C could be involved in neuroblastoma differentiation. Moreover, taking into account the significance of differentiation stage in the neuroblastoma tumor progression we have also studied a possible role of Lamin A/C in the tumorigenesis of this neuronal cancer. As differentiating stimulus we used the all-trans retinoic acid (RA), the most effective compound which has been shown to induce differentiation in neuroblastoma cells. To get insight into the impairment of cell differentiation produced by the LMNA (Lamin A/C) silencing in SHSY5Y cells, we compared the gene expression profile of control and silenced cells both in Retinoic Acid treated and untreated samples, using the one-color Agilent microarray platform. Four condition experiment: cells infected with a mock vector (Mock cells), treated and untreated with retinoic acid (RA); cells infected with a silencing vector for LMNA (LMNA-KD cells), treated and untreated with retinoic acid.
2013-07-11 | E-GEOD-30677 | biostudies-arrayexpress