SIRT1 redistribution on chromatin promotes genome stability but alters gene expression during aging
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE13121 | GEO | 2008/11/26
SECONDARY ACCESSION(S): PRJNA109659
REPOSITORIES: GEO
Similar Datasets
Project description:Genomic instability and alterations in gene expression are hallmarks of eukaryotic aging. The yeast histone deacetylase Sir2 silences transcription and stabilizes repetitive DNA, but during aging or in response to a DNA break, the Sir complex relocalizes to sites of genomic instability, resulting in the desilencing of genes that cause sterility, a characteristic of yeast aging. Using embryonic stem cells, we show that mammalian Sir2, SIRT1, represses repetitive DNA and a functionally diverse set of genes across the mouse genome. In response to DNA damage, SIRT1 dissociates from these loci and relocalizes to DNA breaks to promote repair, resulting in transcriptional changes that parallel those in the aging mouse brain. Increased SIRT1 expression promotes survival in a mouse model of genomic instability and suppresses age-dependent transcriptional changes. Thus, DNA damage-induced redistribution of SIRT1 and other chromatin-modifying proteins may be a conserved mechanism of aging in eukaryotes.
| S-EPMC2853975 | biostudies-literature
Project description:This SuperSeries is composed of the following subset Series: GSE13075: SIRT1 and H1AcK26 promoter-association in mouse ES cells changes upon oxidative stress GSE13120: Age-related gene expression changes in mouse neocortex Refer to individual Series
2010-05-15 | E-GEOD-13121 | biostudies-arrayexpress
Project description:Genome instability is a hallmark of aging and contributes to age-related disorders such as cancer and Alzheimer's disease. The accumulation of DNA damage during aging has been linked to altered cell cycle dynamics and the failure of cell cycle checkpoints. Here, we use single cell imaging to study the consequences of increased genomic instability during aging in budding yeast and identify striking age-associated genome missegregation events. This breakdown in mitotic fidelity results from the age-related activation of the DNA damage checkpoint and the resulting degradation of histone proteins. Disrupting the ability of cells to degrade histones in response to DNA damage increases replicative lifespan and reduces genomic missegregations. We present several lines of evidence supporting a model of antagonistic pleiotropy in the DNA damage response where histone degradation, and limited histone transcription are beneficial to respond rapidly to damage but reduce lifespan and genomic stability in the long term.
| S-EPMC6850777 | biostudies-literature
Project description:Background Antisense long noncoding RNAs (lnc RNA s) are single-stranded RNA s that overlapped gene-coding regions on the opposite DNA strand and play as critical regulators in cardiovascular diseases. The high conservation and stability may be good advantages for antisense lnc RNA s. However, the roles of antisense lnc RNA s in cardiomyocyte proliferation and cardiac regeneration are still unknown. Methods and Results In this study, we found that Silent information regulator factor 2 related enzyme 1 (Sirt1) antisense lnc RNA expression was significantly increased during heart development. By gain and loss function of Sirt1 antisense lnc RNA using adenovirus and locked nucleic acid, respectively, we demonstrated that Sirt1 antisense lnc RNA promoted cardiomyocyte proliferation in vitro and in vivo, and the suppression of Sirt1 antisense lnc RNA inhibited cardiomyocyte proliferation. Moreover, overexpression of Sirt1 antisense lnc RNA enhanced cardiomyocyte proliferation, attenuated cardiomyocyte apoptosis, improved cardiac function, and decreased mortality rate after myocardial infarction. Furthermore, Sirt1 antisense lnc RNA can bind the Sirt1 3'-untranslated region, enhancing the stability of Sirt1 and increasing Sirt1 abundance at both the mRNA and protein levels. Finally, we found that Sirt1 was involved in Sirt1 antisense lnc RNA -induced cardiomyocyte proliferation. Conclusions The present study identified Sirt1 antisense lnc RNA as a novel regulator of cardiomyocyte proliferation and cardiac regeneration by interacting and stabilizing Sirt1 mRNA , which may serve as an effective gene target for preventing myocardial infarction.
| S-EPMC6404207 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below.
2016-08-08 | GSE54451 | GEO
Project description:The decline in adaptive immunity, T lymphocyte output, and the contraction of the TCR repertoire with age is largely attributable to thymic involution. The loss of thymic function with age may be due to diminished numbers of progenitors and the loss of critical cytokines and hormones from the thymic microenvironment. We have previously demonstrated that the orexigenic hormone ghrelin is expressed by immune cells and regulates T cell activation and inflammation. Here we report that ghrelin and ghrelin receptor expression within the thymus diminished with progressive aging. Infusion of ghrelin into 14-month-old mice significantly improved the age-associated changes in thymic architecture and thymocyte numbers, increasing recent thymic emigrants and improving TCR diversity of peripheral T cell subsets. Ghrelin-induced thymopoiesis during aging was associated with enhanced early thymocyte progenitors and bone marrow-derived Lin(-)Sca1(+)cKit(+) cells, while ghrelin- and growth hormone secretagogue receptor-deficient (GHS-R-deficient) mice displayed enhanced age-associated thymic involution. Leptin also enhanced thymopoiesis in aged but not young mice. Our findings demonstrate what we believe to be a novel role for ghrelin and its receptor in thymic biology and suggest a possible therapeutic benefit of harnessing this pathway in the reconstitution of thymic function in immunocompromised subjects.
| S-EPMC1964507 | biostudies-literature
Project description:Chromatin structure affects the accessibility of DNA to transcription, repair, and replication. Changes in chromatin structure occur during development, but less is known about changes during aging. We examined the state of chromatin structure and its effect on gene expression during aging in Drosophila at the whole genome and cellular level using whole-genome tiling microarrays of activation and repressive chromatin marks, whole-genome transcriptional microarrays and single-cell immunohistochemistry. We found dramatic reorganization of chromosomal regions with age. Mapping of H3K9me3 and HP1 signals to fly chromosomes reveals in young flies the expected high enrichment in the pericentric regions, the 4th chromosome, and islands of facultative heterochromatin dispersed throughout the genome. With age, there is a striking reduction in this enrichment resulting in a nearly equivalent level of H3K9me3 and HP1 in the pericentric regions, the 4th chromosome, facultative heterochromatin, and euchromatin. These extensive changes in repressive chromatin marks are associated with alterations in age-related gene expression. Large-scale changes in repressive marks with age are further substantiated by single-cell immunohistochemistry that shows changes in nuclear distribution of H3K9me3 and HP1 marks with age. Such epigenetic changes are expected to directly or indirectly impinge upon important cellular functions such as gene expression, DNA repair, and DNA replication. The combination of genome-wide approaches such as whole-genome chromatin immunoprecipitation and transcriptional studies in conjunction with single-cell immunohistochemistry as shown here provide a first step toward defining how changes in chromatin may contribute to the process of aging in metazoans.
| S-EPMC2980570 | biostudies-literature
Project description:Spindlin1 is a histone reader with three Tudor-like domains and its reader activity of histone methylation could be attenuated by SPINDOC. To validate such a role in cellular context, we performed ChIP-Seq in HEK293 cell with SPINDOC overexpressed cell line and control cell line.
2023-11-18 | GSE247551 | GEO
Project description:The mammalian SWI/SNF complex, or BAF complex, has a conserved and direct role in antagonizing Polycomb-mediated repression. Yet, BAF also promotes repression by Polycomb in stem cells and cancer. How BAF both antagonizes and promotes Polycomb-mediated repression remains unknown. Here, we utilize targeted protein degradation to dissect the BAF-Polycomb axis in mouse embryonic stem cells on short timescales. We report that rapid BAF depletion redistributes Polycomb repressive complexes PRC1 and PRC2 from highly occupied domains, like Hox clusters, to weakly occupied sites normally opposed by BAF. Polycomb redistribution from highly repressed domains results in their decompaction, gain of active epigenomic features and transcriptional derepression. Surprisingly, through dose-dependent degradation of PRC1 and PRC2, we identify a conventional role for BAF in Polycomb-mediated repression, in addition to global Polycomb redistribution. These findings provide new mechanistic insight into the highly dynamic state of the Polycomb-Trithorax axis.
| S-EPMC8504423 | biostudies-literature
Project description:Sarcopenia is the age-related progressive loss of skeletal muscle mass and strength finally leading to poor physical performance. Impaired myogenesis contributes to the pathogenesis of sarcopenia, while mitochondrial dysfunctions are thought to play a primary role in skeletal muscle loss during aging. Here we studied the link between myogenesis and metabolism. In particular, we analyzed the effect of the metabolic modulator trimetazidine (TMZ) on myogenesis in aging. We show that reprogramming the metabolism by TMZ treatment for 12 consecutive days stimulates myogenic gene expression in skeletal muscle of 22-month-old mice. Our data also reveal that TMZ increases the levels of mitochondrial proteins and stimulates the oxidative metabolism in aged muscles, this finding being in line with our previous observations in cachectic mice. Moreover, we show that, besides TMZ also other types of metabolic modulators (i.e., 5-Aminoimidazole-4-Carboxamide Ribofuranoside-AICAR) can stimulate differentiation of skeletal muscle progenitors in vitro. Overall, our results reveal that reprogramming the metabolism stimulates myogenesis while triggering mitochondrial proteins synthesis in vivo during aging. Together with the previously reported ability of TMZ to increase muscle strength in aged mice, these new data suggest an interesting non-invasive therapeutic strategy which could contribute to improving muscle quality and neuromuscular communication in the elderly, and counteracting sarcopenia.
| S-EPMC6636331 | biostudies-literature