During development of the mammalian central nervous system (CNS), neurons and glial cells (astrocytes and oligodendrocytes) are generated from common neural precursor cells (NPCs). However, neurogenesis precedes gliogenesis, which normally commences at later stages of fetal telencephalic development. Astrocyte differentiation of mouse NPCs at embryonic day (E) 14.5 (relatively late gestation) is induced by activation of the transcription factor STAT3, whereas at E11.5 (mid-gestation) NPCs do not differentiate into astrocytes even when stimulated by STAT3-activating cytokines such as leukemia inhibitory factor (LIF). This can be explained in part by the fact that astrocyte-specific gene promoters are highly methylated in NPCs at E11.5, but other mechanisms are also likely to play a role. We therefore sought to identify genes involved in the inhibition of astrocyte differentiation of NPCs at midgestation. We first examined gene expression profiles in E11.5 and E14.5 NPCs, using Affymetrix GeneChip analysis, applying the Percellome method to normalize gene expression level. We then conducted in situ hybridization analysis for selected genes found to be highly expressed in NPCs at midgestation. Among these genes, we found that N-myc and high mobility group AT-hook 2 (Hmga2) were highly expressed in the E11.5 but not the E14.5 ventricular zone of mouse brain, where NPCs reside. Transduction of N-myc and Hmga2 by retroviruses into E14.5 NPCs, which normally differentiate into astrocytes in response to LIF, resulted in suppression of astrocyte differentiation. However, sustained expression of N-myc and Hmga2 in E11.5 NPCs failed to maintain the hypermethylated status of an astrocyte-specific gene promoter. Taken together, our data suggest that astrocyte differentiation of NPCs is regulated not only by DNA methylation but also by genes whose expression is controlled spatio-temporally during brain development.
Identification of genes that restrict astrocyte differentiation of midgestational neural precursor cells.
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View SamplesTo elucidate the fundamental molecular mechanisms responsible for multistep hepatotumorigenesis, this study investigated genes that were upregulated in a stepwise manner from the nave liver condition through to chronic oxidative stress-induced hepatitis and liver tumor by time-series microarray analysis. The time-dependent gene expression profile should reflect the multistep process of hepatotumorigenesis, and might identify genes that function specifically in hepatotumorigenesis.
IQGAP1 and vimentin are key regulator genes in naturally occurring hepatotumorigenesis induced by oxidative stress.
Sex, Age, Specimen part, Disease
View SamplesIn the present study, we investigated the importance of histone deacetylase 6 (HDAC6) for glucocorticoid receptor (GR) mediated effects on glucose metabolism, and its potential as a therapeutic target for the prevention of glucocorticoid (GC)-induced diabetes. Dexamethasone (dex)-induced hepatic glucose output and GR translocation were analysed in wildtype (wt) and HDAC6-deficient (HDAC6ko) mice. The effect of the specific HDAC6-inhibitor tubacin was analysed in-vitro. Wt and HDAC6ko mice were subjected to 3 weeks dex treatment before analysis of glucose and insulin tolerance. HDAC6ko mice showed impaired dex-induced hepatic GR translocation. Accordingly, dex induced expression of a large number of hepatic genes was significantly attenuated in mice lacking HDAC6 and by tubacin in-vitro. Glucose output of primary hepatocytes from HDAC6ko mice was diminished. A significant improvement of dex-induced whole-body glucose intolerance as well as insulin resistance in HDAC6ko mice compared to wt littermates was observed. The present study demonstrates that HDAC6 is an essential regulator of hepatic GC stimulated gluconeogenesis and impairment of whole body glucose metabolism through modification of GR nuclear translocation. Selective pharmacological inhibition of HDAC6 may provide a future therapeutic option against the pro-diabetogenic actions of GCs.
Histone deacetylase 6 (HDAC6) is an essential modifier of glucocorticoid-induced hepatic gluconeogenesis.
Sex, Specimen part, Treatment
View SamplesSmall endogenous C. elegans RNAs from L4 and young adult worms were prepared for sequencing using a protocol derived from Batista et al., (2008) and Lau et al. (2001). The small-RNA libraries were constructed using a method that does not require a 5' monophosphate (called 5' monophosphate-independent method, Ambros et al., 2003) to profile secondary siRNAs that have 5' triphosphorylated G. All preprocessed small-RNA reads were mapped to genome (ce6), allowing no mismatches. After excluding miRNAs, 21U RNAs, rRNAs, and other structural ncRNAs, the remaining reads were classified as 22G RNAs, 26G RNAs, and other siRNAs, based on their length and 5' terminal nucleotide. Overall design: Small-RNA libraries were sequenced in L4 and young adult stages in C.elegans.
Long noncoding RNAs in C. elegans.
Cell line, Subject
View SamplesSince Japanese quail and chicken belong to the same order Galliforms, DNA sequence of both species are highly conserved and proved to be applicable for various analyses each other. Quail are commonly used to address physiological questions for reasons of economy.
Thyrotrophin in the pars tuberalis triggers photoperiodic response.
No sample metadata fields
View SamplesIn cell stress, mRNA in the cytoplasm is sequestered to the insoluble ribonucleoprotein (RNP) compartments containing stress granules. These RNP granules are known to be involved in the control of mRNA processing and decay, but it has been elusive whether the mRNA redistribution in cell stress is universal or specific to a subset of transcripts. Here we provide a transcriptome-wide profiles of the RNP granules in cell stress and show that mRNA accumulation in stress granule differentially affects individual transcripts. mRNA species accumulated in stress granules are largely conserved across distinct stress types, such as in endoplasmic reticulum stress, heat shock and arsenic stress. Many mRNA species involved in cell survival and proliferation are more dynamically redistributed, suggesting that mRNA sequestration can be a specific response mechanism through which cells can reshape the landscape of their transcriptome and affect the cell fate determination in stress conditions . Overall design: 24 samples are analyzed, which include 3 replicates for control (DMSO) cytoplasmic fraction, 3 replicates of control (DMSO) RNP granule fraction, 3 replicates of Thapsigargin treated cytoplasmic fraction, 3 replicates of Thapsigargin treated RNP granule fraction, 2 replicates of control (H2O) cytoplasmic fraction, 2 replicates of control (H2O) RNP granule fractions, 2 replicates of heat shock (HS) treated cytoplsmic fraction (HS), 2 replicates of heat shock (HS) treated RNP granule fraction, 2 replicates of arsenite treated cytoplasmic fraction, and 2 replicates of arsenite treated RNP granule fraction.
Systematic Characterization of Stress-Induced RNA Granulation.
Cell line, Treatment, Subject
View SamplesBP and ER encode proteins that act synergistically to regulate Arabidopsis inflorescence architecture. To search for genes/proteins that influence the BP/ER signaling pathways, we conducted mutagenesis of the bp er double mutant and found that a mutation in FILAMENTOUS FLOWER (FIL) suppresses many of the morphological/developmental defects in bp er. Given that FIL encodes a Zn-finger containing transcription factor, microarray analysis was conducted on bp er vs. the bp er fil line to identify genes that are misregulated and which might implicate specific genes/proteins/pathways that are involved in regulating inflorescence development.
A novel Filamentous Flower mutant suppresses brevipedicellus developmental defects and modulates glucosinolate and auxin levels.
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View SamplesA chemical screen was performed in search of compounds that modify plant responses to sucrose. This screen uncovered that sulfamethoxazole (SMX), a folate biosynthesis inhibitor, acted synergistically with sucrose to inhibit hypocotyl elongation, suggesting interaction between these two pathways. Transcriptome analysis was performed to identify changes in transcript abundance that may underpin crosstalk between sucrose and SMX. Three-day-old dark-grown seedlings were treated to sucrose and SMX at concentrations that induced no change in hypocotyl elongation when administered independently, yet restricted elongation when both were present in the growth media (10mM and 0.2M, respectively). This analysis uncovered multiple core auxin signalling components that exhibit altered transcript abundance in response to co-treatment with sucrose and SMX, suggesting that auxin signalling mediates crosstalk between these two pathways. This study highlights an input through which metabolic status can shape plant growth and development through hormone signalling.
Interplay between sucrose and folate modulates auxin signaling in Arabidopsis.
Specimen part
View SamplesGametogenesis is dependent on the expression of germline-specific genes. However, it remains unknown how the germline epigenome is distinctly established from that of somatic lineages. Here we show that genes commonly expressed in somatic lineages and spermatogenesis-progenitor cells undergo repression in a genome-wide manner in late stages of the male germline and identify underlying mechanisms. SCML2, a germline-specific subunit of a Polycomb repressive complex 1 (PRC1), establishes the unique epigenome of the male germline through two distinct antithetical mechanisms. SCML2 works with PRC1 and promotes RNF2-dependent ubiquitination of H2A, thereby marking somatic/progenitor genes on autosomes for repression. Paradoxically, SCML2 also prevents RNF2-dependent ubiquitination of H2A on sex chromosomes during meiosis, thereby enabling unique epigenetic programming of sex chromosomes for male reproduction. Our results reveal divergent mechanisms involving a shared regulator by which the male germline epigenome is distinguished from that of the soma and progenitor cells. Overall design: RNA-seq and ChIP-seq analyses using wild-type and Scml2-KO spermatogenic cells
Poised chromatin and bivalent domains facilitate the mitosis-to-meiosis transition in the male germline.
No sample metadata fields
View SamplesHigh throughput massively parallel sequencing on mRNA libraries generated from cortices of bexarotene or vehicle treated APP/PS1 Overall design: Read counts analyzed for differential gene expression using edgeR
RNA-sequencing reveals transcriptional up-regulation of Trem2 in response to bexarotene treatment.
Specimen part, Cell line, Subject
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