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Caenorhabditis elegans
46 Downloadable Samples
Affymetrix C. elegans Genome Array (celegans)
Description
Dietary restriction extends lifespan and delays the age-related physiological decline in many species. Intermittent fasting (IF) is one of the most effective dietary restriction regimens that extends lifespan in C. elegans and mammals1,2. In C. elegans, the FOXO transcription factor DAF-16 is implicated in fasting-induced gene expression changes and the longevity response to IF3; however, the mechanisms that sense and transduce fasting-stress stimuli have remained largely unknown. Here we show that a KGB-1/AP1 (activator protein 1) module is a key signalling pathway that mediates fasting-induced transcriptional changes and IF-induced longevity. Our promoter analysis coupled to genome-wide microarray results has shown that the AP-1-binding site, together with the FOXO-binding site, is highly over-represented in the promoter regions of fasting-induced genes. We find that JUN-1 (C. elegans c-Jun) and FOS-1 (C. elegans c-Fos), which constitute the AP-1 transcription factor complex, are required for IF-induced longevity. We also find that KGB-1 acts as a direct activator of JUN-1 and FOS-1, is activated in response to fasting, and, among the three C. elegans JNKs, is specifically required for IF-induced longevity. Our results demonstrate that most fasting-induced upregulated genes, including almost all of the DAF-16-dependent genes, require KGB-1 and JUN-1 function for their induction, and that the loss of kgb-1 suppresses the fasting-induced upregulation of DAF-16 target genes without affecting fasting-induced DAF-16 nuclear translocation. These findings identify the evolutionarily conserved JNK/AP-1 module as a key mediator of fasting-stress responses, and suggest a model in which two fasting-induced signalling pathways leading to DAF-16 nuclear translocation and KGB-1/AP-1 activation, respectively, integrate in the nucleus to coordinately mediate fasting-induced transcriptional changes and IF-induced longevity.
Publication Title
A fasting-responsive signaling pathway that extends life span in C. elegans.
Sample Metadata Fields
Treatment
View Samples- Caenorhabditis elegans
- 24 Downloadable Samples
- Affymetrix C. elegans Genome Array (celegans)
Description
Dietary restriction (DR) is the most effective and reproducible intervention to extend lifespan in divergent species1. In mammals, two regimens of DR, intermittent fasting (IF) and caloric restriction (CR), have proven to extend lifespan and reduce the incidence of age-related disorders2. An important characteristic of IF is that it can increase lifespan, even when there is little or no overall decrease in calorie intake2. The molecular mechanisms underlying IF-induced longevity, however, remain largely unknown. Here we establish an IF regimen that effectively extends the lifespan of Caenorhabditis elegans, and show that a nutrient-related signalling molecule, the low molecular weight GTPase Cel-Rheb, has a dual role in lifespan regulation; Cel-Rheb is required for the IF-induced longevity, whereas inhibition of Cel-Rheb mimics the CR effects. We also show that Cel-Rheb exerts its effects in part via the insulin/IGF-like signalling effector DAF-16 in IF, and that Cel-Rheb is required for fasting-induced nuclear translocation of DAF-16. We find that HSP-12.6, a DAF-16 target, functions to mediate the IF-induced longevity. Furthermore, our analyses demonstrate that most of fasting-induced upregulated genes require Cel-Rheb function for their induction, and that Cel-Rheb/Cel-TOR signalling is required for the fasting-induced downregulation of an insulin-like peptide, INS-7. These findings identify the essential role of signalling via Cel-Rheb in IF-induced longevity and gene expression changes, and suggest a molecular link between the IF-induced longevity and the insulin/IGF-like signalling pathway.
Publication Title
Signalling through RHEB-1 mediates intermittent fasting-induced longevity in C. elegans.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 19 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
The ERK family of MAP kinase plays a critical role in growth factor-stimulated cell cycle progression from G0/G1 to S phase. But, how sustained activation of ERK promotes G1 progression has remained unclear. Here, our systematic analysis on the temporal program of ERK-dependent gene expression shows that sustained activation of ERK is required for induction and maintenance of the decreased expression levels of a set of genes. Moreover, our cell biological analysis reveals that these ERK-dependent downregulated genes have the ability to block S phase entry. Cessation of ERK activation at mid or late G1 leads to a rapid increase of these anti-proliferative genes and results in the inhibition of S phase entry. These findings uncover an important mechanism by which the duration of ERK activation regulates cell cycle progression through dynamic changes in gene expression, and identify novel ERK target genes crucial for the regulation of cell cycle progression.
Publication Title
Continuous ERK activation downregulates antiproliferative genes throughout G1 phase to allow cell-cycle progression.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Preimplantation development is a crucial step for successful implantation and pregnancy. Although both compaction and blastocyst formation have been extensively studied, mechanisms regulating early cell division stages before compaction have remained unclear. Here, we show that ERK MAP kinase function is required for early embryonic cell division and normal cell-cell adhesion before compaction. Our analysis demonstrates that inhibition of ERK activation in the late 2-cell stage embryos leads to a reversible arrest in G2 phase in the 4-cell stage. The G2 arrested, 4-cell stage embryos show weakened cell-cell adhesion as compared to control embryos. Remarkably, microarray analyses show that most of the programmed changes of upregulated and downregulated gene expression during the 4- to 8-cell stages normally proceed in the 4-cell stage-arrested embryos, except for a portion of the genes whose expression profiles closely parallel the stages of embryonic development when arrested in G2 and released to resume development. These parallel genes include the genes encoding intercellular adhesion molecules, whose expression is found to be positively regulated by the ERK pathway. We also show that while ERK inactivation in the 8-cell stage embryos does not lead to cell division arrest, it does cause cell division arrest when cadherin-mediated cell-cell adhesion is disrupted. These results demonstrate an essential role of ERK function in the G2/M transition and the expression of adhesion molecules during the 2-cell to 8-cell stage embryos, and suggest a loose parallelism between the gene expression programs and the developmental stages before compaction.
Publication Title
Requirement for ERK MAP kinase in mouse preimplantation development.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 12 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
It remains controversial whether the routes from differentiated cells to iPSCs are related to the reverse order of normal developmental processes or independent of them. Here, we generated iPSCs from mouse astrocytes by three (Oct3/4, Klf4 and Sox2 (OKS)), two (OK), or four (OKS plus c-Myc) factors. Sox1, a neural stem cell (NSC)-specific transcription factor, is transiently upregulated during reprogramming and Sox1-positive cells become iPSCs. The upregulation of Sox1 is essential for OK-induced reprogramming. Genome-wide analysis revealed that the gene expression profile of Sox1-expressing intermediate-state cells resembles that of NSCs. Furthermore, the intermediate-state cells are able to generate neurospheres, which can differentiate into both neurons and glial cells. Remarkably, during MEF reprogramming, neither Sox1 upregulation nor an increase in neurogenic potential occurs. Thus, astrocytes are reprogrammed through an NSC-like state, suggesting that reprogramming partially follows the retrograde pathway of normal developmental processes.
Publication Title
Induction of Pluripotency in Astrocytes through a Neural Stem Cell-like State.
Sample Metadata Fields
Specimen part
View Samples- Xenopus laevis
- 12 Downloadable Samples
- Affymetrix Xenopus laevis Genome 2.0 Array (xlaevis2)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
The atypical mitogen-activated protein kinase ERK3 is essential for establishment of epithelial architecture.
Sample Metadata Fields
Specimen part, Treatment
View Samples
GSE37305- Caenorhabditis elegans
- 12 Downloadable Samples
- Affymetrix C. elegans Genome Array (celegans)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
The Sexual Dimorphism of Dietary Restriction Responsiveness in Caenorhabditis elegans.
Sample Metadata Fields
Sex, Specimen part, Treatment
View Samples- Caenorhabditis elegans
- 11 Downloadable Samples
- Affymetrix C. elegans Genome Array (celegans)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
The microRNA machinery regulates fasting-induced changes in gene expression and longevity in <i>Caenorhabditis elegans</i>.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus
- 10 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
In skeletal muscle differentiation, muscle-specific genes are regulated by two groups of transcription factors, the MyoD and MEF2 families, which work together to drive the differentiation process. Here we show that ERK5 regulates muscle cell fusion through Klf transcription factors. The inhibition of ERK5 activity suppresses muscle cell fusion with minimal effects on the expression of MyoD, MEF2, and their target genes. Promoter analysis coupled to microarray assay reveals that Klf-binding motifs are highly enriched in the promoter regions of ERK5-dependent upregulated genes. Remarkably, Klf2 and Klf4 expression are also upregulated during differentiation in an ERK5-dependent manner, and knockdown of Klf2 or Klf4 specifically suppresses muscle cell fusion. Moreover, we show that the Sp1 transcription factor links ERK5 to Klf2/4, and that nephronectin, a Klf transcriptional target, is involved in muscle cell fusion. Therefore, an ERK5/Sp1/Klf module plays a key role in the fusion process during skeletal muscle differentiation.
Publication Title
ERK5 regulates muscle cell fusion through Klf transcription factors.
Sample Metadata Fields
Cell line, Time
View Samples- Caenorhabditis elegans
- 10 Downloadable Samples
- Affymetrix C. elegans Genome Array (celegans)
Description
Intermittent fasting is one of the most effective dietary restriction regimens that extend life-span in C. elegans and mammals. Fasting-stimulus responses are key to the longevity response; however, the mechanisms that sense and transduce fasting-stimulus have remained largely unknown. Through a comprehensive transcriptome analysis in C. elegans, we have found that along with the FOXO transcription factor DAF-16, AP-1 (JUN-1/FOS-1) plays a central role in fasting-induced transcriptional changes. KGB-1, one of the C. elegans JNKs, acted as an activator of AP-1, and was activated in response to fasting. KGB-1 and AP-1 were involved in intermittent fasting-induced longevity. Fasting-induced upregulation of the components of the SCF E3 ubiquitin ligase complex via AP-1 and DAF-16 enhanced protein ubiquitination, and reduced protein carbonylation. Our results have thus identified a fasting-responsive KGB-1/AP-1 signaling pathway, which, together with DAF-16, causes transcriptional changes that mediate longevity partly through regulating proteostasis.
Publication Title
A fasting-responsive signaling pathway that extends life span in C. elegans.
Sample Metadata Fields
Treatment
View Samples