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.
ERK5 regulates muscle cell fusion through Klf transcription factors.
Cell line, Time
View SamplesThis experiment is to identify genes that are regulated by pRb in AC61 cells. AC61 cells were derived from a C-cell adenocarcinoma developed in an Rb+/-N-ras-/- mouse.
Rb Regulates DNA damage response and cellular senescence through E2F-dependent suppression of N-ras isoprenylation.
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View SamplesExpression data from mice exposed to intermittent hypoxia and mice reared for 12 months. We used microarrays to analyze the transcriptome of hippocampus from mice exposed to intermittent hypoxia or aged mice.
Treatment of intermittent hypoxia increases phosphorylated tau in the hippocampus via biological processes common to aging.
Specimen part, Treatment
View SamplesThis array set was used to identify the genes that are highly expressed in the mouse suprachiasmatic nucleus (SCN). Because pharmacological inhibition of Gai/o activity with pertussis toxin hampers intercellular synchronization and causes dampened rhythms of the entire SCN, we hypothesized that member(s) of the Regulator of G protein Signaling (RGS) family might contribute to synchronized cellular oscillations in the SCN. To test this hypothesis, we surveyed all known mouse Rgs genes for their expression by using GeneChip and selected the genes that are highly expressed in the SCN for further analysis.
Circadian regulation of intracellular G-protein signalling mediates intercellular synchrony and rhythmicity in the suprachiasmatic nucleus.
Sex, Age, Specimen part, Disease, Treatment, Time
View SamplesForced expression of Bmi1 accelerated the self-renewal of hepatic stem/progenitor cells and eventually induced their transformation in an in vivo transplant model. The Ink4a/Arf locus, which encodes a cyclin-dependent kinase inhibitor, p16Ink4a, and a tumor suppressor, p19Arf, is a pivotal target of Bmi1. Therefore, it would be of importance to understand the contribution of the Ink4a/Arf locus to Bmi1 oncogenic functions in cancer and search for as-yet-unknown Bmi1 target genes other than Ink4a/Arf. We used microarrays to explore novel candidate downstream targets for Bmi1 in hepatic stem/progenitor cells
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Specimen part
View SamplesThe polycomb group (PcG) proteins function in gene silencing through histone modifications. They form chromatin-associated multiprotein complexes, termed polycomb repressive complex (PRC) 1 and PRC2. These two complexes work in a coordinated manner in the maintenance of cellular memories through transcriptional repression of target genes. EZH2 is a catalytic component of PRC2 and trimethylates histone H3 at lysine 27 to transcriptionally repress the target genes. PcG proteins have been characterized as general regulators of stem cells, but recent works also unveiled their critical roles in cancer.
No associated publication
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View SamplesComparison between livers of FLS mice and livers of DS (DD shionogi) mice
No associated publication
Specimen part
View SamplesTo identify p45 target genes, we conducted gene expression profiling with p45-null megakaryocytes cultured from E14.5 fetal liver. Many genes encoding membrane proteins and enzymes related to platelet function, including Txas, Glycoprotein 6 (Gp6) and Selectin P (Selp), were repressed in the absence of p45. Considering the similar DNA binding specificity of p45 and Nrf2 in vitro, we expected p45 to activate cytoprotective genes that are established Nrf2 targets. However, the expression of numerous detoxifying enzymes and stress-responsive genes, including NAD(P)H:quinone oxidoreductase (Nqo1), were increased in the absence of p45.
No associated publication
Sex, Specimen part
View SamplesPerilipin A (PeriA) exclusively locates on adipocyte lipid droplets and is essential for lipid storage and lipolysis. Adipocyte specific overexpression of PeriA caused resistance to diet-induced obesity and resulted in improved insulin sensitivity. In order to better understand the biological basis for this observed phenotype we performed DNA microarray analysis on white adipose tissue (WAT) from PeriA transgenic (Tg) and control wildtype (WT) mice.
Perilipin overexpression in white adipose tissue induces a brown fat-like phenotype.
Sex, Specimen part
View SamplesSpecification of germ cell fate is fundamental in development. With a highly representative single-cell microarray and rigorous quantitative-PCR analysis, we defined the genome-wide transcription dynamics that create primordial germ cells (PGCs) from the epiblast, a process that exclusively segregates them from their somatic neighbors. We also analyzed the effect of the loss of Blimp1, a key transcriptional regulator, on these dynamics. Our analysis revealed that PGC specification involves complex, yet highly ordered regulation of a large number of genes, proceeding under the strong influence of mesoderm induction with active repression of specific programs such as epithelial-mesenchymal transition, Hox gene activation, cell-cycle progression and DNA methyltransferase machinery. Remarkably, Blimp1 is essential for repressing nearly all the genes normally down-regulated in PGCs relative to their somatic neighbors, whereas it is dispensable for the activation of approximately half of the genes up-regulated in PGCs.
No associated publication
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