Changes in nuclear lamin-B stability marks the onset of aging in Drosophila
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PROVIDER: PRJNA649516 | ENA |
REPOSITORIES: ENA
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Project description:In this study, we showed that reduced nuclear lamin-B marks the onset of physiological decline in young adult Drosophila and its ectopic expression in dopaminergic neurons is sufficient to improve their locomotor activity during aging. Furthermore, the decline in lamin-B protein appeared to be unrelated to its mRNA level. Instead, we found drastic changes to its protein solubility during aging. Given the importance of nuclear lamin-B in genome organization and the advancement of single-cell epigenome profiling technology, our findings provide the community the basis to further study how altered level of lamin-B protein may elicit changes in gene expression that can contribute to the onset of physiological decline in animals.
2021-11-30 | GSE155357 | GEO
Project description:Epigenetic alterations occur during aging, but it remains unclear what epigenetic features are associated with the onset of physiological decline in animals. Nuclear lamin-B forms the filamentous meshwork underneath the nuclear envelope, providing the structural scaffold necessary for genome organization and gene regulation. We found that reduced level of nuclear lamin-B protein coincides with the decline in locomotor activity and stress resistance in young adult male Drosophila. Ubiquitous lamin-B expression improves locomotor activity of the male flies at the expense of lower stress resistance and shorten lifespan. This observation suggests that tissue-specific expression of lamin-B may regulate different aspects of animal physiology during aging. To test this hypothesis, specific GAL-4 lines were used to drive the expression of lamin-B in specific neuronal populations and muscle tissues in male flies. Ectopic expression of lamin-B in the dopaminergic neurons within the protocerebral anterior medial region of the brain improves the locomotor activity of the male flies with little impact on their stress responses and lifespan. Interestingly, age-dependent decrease in the level of lamin-B protein is independent of its mRNA expression. Instead, cellular thermal shift assay showed that lamin-B and CP190 insulator protein undergo significant change in their solubility during aging. This suggests that the increased solubility of lamin-B protein may contribute to its reduced stability and degradation during aging.
| S-EPMC8947137 | biostudies-literature
Project description:Nuclear envelope (NE) ruptures are emerging observations in Lamin-related dilated cardiomyopathy, an adult-onset disease caused by loss-of-function mutations in Lamin A/C, a nuclear lamina component. Here, we test a prevailing hypothesis that NE ruptures trigger the pathological cGAS-STING cytosolic DNA-sensing pathway using a mouse model of Lamin cardiomyopathy. The reduction of Lamin A/C in cardiomyocytes of adult mice causes pervasive NE ruptures in cardiomyocytes, preceding inflammatory transcription, fibrosis, and fatal dilated cardiomyopathy. NE ruptures are followed by DNA damage accumulation without causing immediate cardiomyocyte death. However, cGAS-STING-dependent inflammatory signaling remains inactive. Deleting cGas or Sting does not rescue cardiomyopathy. The lack of cGAS-STING activation is likely due to the near absence of cGAS expression in adult cardiomyocytes at baseline. Instead, extracellular matrix (ECM) signaling is activated and predicted to initiate pro-inflammatory communication from Lamin-reduced cardiomyocytes to fibroblasts. Our work nominates ECM signaling, not cGAS-STING, as a potential inflammatory contributor in Lamin cardiomyopathy.
2024-04-26 | GSE241577 | GEO
Project description:Nuclear envelope (NE) ruptures are emerging observations in Lamin-related dilated cardiomyopathy, an adult-onset disease caused by loss-of-function mutations in Lamin A/C, a nuclear lamina component. Here, we test a prevailing hypothesis that NE ruptures trigger the pathological cGAS-STING cytosolic DNA-sensing pathway using a mouse model of Lamin cardiomyopathy. The reduction of Lamin A/C in cardiomyocytes of adult mice causes pervasive NE ruptures in cardiomyocytes, preceding inflammatory transcription, fibrosis, and fatal dilated cardiomyopathy. NE ruptures are followed by DNA damage accumulation without causing immediate cardiomyocyte death. However, cGAS-STING-dependent inflammatory signaling remains inactive. Deleting cGas or Sting does not rescue cardiomyopathy. The lack of cGAS-STING activation is likely due to the near absence of cGAS expression in adult cardiomyocytes at baseline. Instead, extracellular matrix (ECM) signaling is activated and predicted to initiate pro-inflammatory communication from Lamin-reduced cardiomyocytes to fibroblasts. Our work nominates ECM signaling, not cGAS-STING, as a potential inflammatory contributor in Lamin cardiomyopathy.
2024-04-26 | GSE241589 | GEO
Project description:Nuclear envelope (NE) ruptures are emerging observations in Lamin-related dilated cardiomyopathy, an adult-onset disease caused by loss-of-function mutations in Lamin A/C, a nuclear lamina component. Here, we test a prevailing hypothesis that NE ruptures trigger the pathological cGAS-STING cytosolic DNA-sensing pathway using a mouse model of Lamin cardiomyopathy. The reduction of Lamin A/C in cardiomyocytes of adult mice causes pervasive NE ruptures in cardiomyocytes, preceding inflammatory transcription, fibrosis, and fatal dilated cardiomyopathy. NE ruptures are followed by DNA damage accumulation without causing immediate cardiomyocyte death. However, cGAS-STING-dependent inflammatory signaling remains inactive. Deleting cGas or Sting does not rescue cardiomyopathy. The lack of cGAS-STING activation is likely due to the near absence of cGAS expression in adult cardiomyocytes at baseline. Instead, extracellular matrix (ECM) signaling is activated and predicted to initiate pro-inflammatory communication from Lamin-reduced cardiomyocytes to fibroblasts. Our work nominates ECM signaling, not cGAS-STING, as a potential inflammatory contributor in Lamin cardiomyopathy.
2024-04-26 | GSE241587 | GEO
Project description:Dynamic interactions of nuclear lamins with chromatin through so-called lamin-associated domains (LADs) contribute to spatial arrangements of the genome. Here, we provide evidence for pre-patterning of differentiation-driven formation of lamin A/C LADs by domains of histone H2B modified by the nutrient sensor O-linked N-acetylglucosamine (H2BGlcNAc), which we term GADs. We demonstrate a two-step process of lamin A/C LAD formation during in vitro adipogenesis, involving (i) a spreading of lamin A/C-chromatin interactions during the transition from progenitor cell proliferation to cell cycle arrest, and (ii) a genome-scale redistribution these interactions through a process of LAD ‘exchange’ within hours of adipogenic induction. Chromatin state modeling reveals that lamin A/C LADs can be found both in active and repressive chromatin contexts which can be influenced by cell differentiation status. De novo formation of adipogenic lamin A/C LADs occurs non-randomly on GADs, consisting of megabase-size intergenic and repressive chromatin domains. Accordingly, while pre-differentiation lamin A/C LADs are gene-rich, post-differentiation LADs harbor repressive features reminiscent of lamin B1 LADs. Moreover, release of lamin A/C from genes directly involved in glycolysis concurs with their transcriptional upregulation after adipogenic induction, and with concordant downstream elevations in H2BGlcNAc levels and O-GlcNAc cycling. Our results unveil an epigenetic pre-patterning of adipogenic LADs by GADs, suggesting a coupling of developmentally regulated lamin A/C-genome interactions to a metabolically sensitive chromatin modification. Examination of LMNA and H2BGlcNAc binding in ASCs across differentiation
2015-09-04 | E-GEOD-63346 | 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:Lamins, the major structural proteins within the nuclear lamina, are crucial for the functionality of cellular nucleus and their alterations are involved in the so-called laminopathies. We previously found that Huntington’s disease (HD), a hereditary neurodegenerative disorder caused by an expansion of a CAG repeat in the huntingtin (htt) gene, courses with increased lamin B protein levels in specific brain regions in both mouse models and patients. We now show that these changes are mostly restricted to lamin B1, occur in striatal medium-sized spiny neurons and CA1 hippocampal neurons, and are accompanied by altered nuclear morphology, nucleocytoplasmic transport disruption and un-structuring of lamin-associated chromatin domains. Normalization of lamin B1 levels by betulinic acid administration in the R6/1 mouse model of HD results in beneficial restoring of nuclear lamina homeostasis and prevention of motor and cognitive dysfunction, opening a window for a new therapeutic approach for HD and other B1-type laminophaties.
2020-11-10 | GSE139884 | GEO
Project description:In mammals, RNA interference (RNAi) is mostly studied as a cytoplasmic event, however, numerous reports convincingly show nuclear localization of the AGO proteins. Nevertheless, the mechanism of nuclear entry remains to be fully elucidated, and the extent of nuclear RNAi further explored. We found that reduced Lamin A levels significantly induced nuclear influx of AGO2 in SHSY5Y neuroblastoma and A375 melanoma cancer cell lines, which normally have no nuclear AGO2. The translocation of AGO2 was accompanied by aggravated cell proliferation and we further found that the loss of Lamin A leads to EGFR and Src kinase activation, which regulates the turnover and stability of cytoplasmic AGO2. Furthermore, Lamin A KO significantly reduced the activity of nuclear RNAi. This was evident by AGO fPAR-CLIP in WT and Lamin A KO cells, where we observed ca 60% less efficiency of RNAi. Mass spectrometry of AGO interactome, from the nuclear fraction, indicated that AGO2 is in complex with FAM120A, a known interactor of AGO2 that reduces the activity of RNAi by competing with AGO2 transcript binding. Therefore, loss of Lamin A starts a signaling cascade that mediates nuclear AGO2 translocation to rapidly inhibit RNAi in order to facilitate cancer proliferation
2024-10-17 | PXD042899 | Pride
Project description:The cytoplasmic functions of Wiskott-Aldrich Syndrome family (WASP) proteins are well known and include roles in cytoskeleton reorganization and membrane-cytoskeletal interactions important for membrane/vesicle trafficking, morphogenesis, immune response and signal transduction. Mis-regulation of these proteins is associated with immune deficiency and metastasis. Cytoplasmic WASP proteins act as effectors of Rho family GTPases and polymerize branched actin through the Arp2/3 complex. However, recent evidence has revealed that this classically cytoplasmic protein family also functions in the nucleus. Previously, we identified Drosophila washout (wash) as a new member of the WASP family with essential cytoplasmic roles in early development. Here we show that Wash is also present in the nucleus and plays a key role in nuclear organization via its interaction with Lamin Dm0 at the nuclear envelope. Wash and Lamin Dm0 occupy similar genomic regions that overlap with transcriptionally silent chromatin including constitutive heterochromatin. Strikingly, wash mutant and knockdown nuclei exhibit the same abnormal wrinkled morphology observed in diverse laminopathies, including the Hutchinson-Gilford progeria syndrome, and consistent with disruption of the nuclear organization of several sub-nuclear structures including cajal bodies and the chromocenter in salivary glands. We also found that Wash and Lamin knockdown disrupt chromatin accessibility of repressive compartments in agreement with an observed global redistribution of repressive histone modifications. Functional genetic approaches show wash mutants exhibit similar phenotypes to lamin Dm0 mutants, suggesting they participate in similar regulatory networks. Our results reveal a novel role for Wash in modulating nuclear organization via its interaction with the nuclear envelope protein Lamin Dm0. These findings highlight the functional complexity of WASP family proteins and provide new venues to understand their molecular roles in cell biology and disease. DamID chromatin profiling demostrate that Wash binds similar regions to those bound by Lamin Dm0, in particular transcriptional silent chromatin
2015-03-10 | GSE59853 | GEO