Polycomb group (PcG) proteins bind to and repress genes in embryonic stem cells and through lineage commitment to the terminal differentiated state. PcG repressed genes are commonly characterized by the presence of the epigenetic histone mark, H3K27me3, catalyzed by the Polycomb repressive complex 2. Here, we present in vivo evidence for a previously unrecognized plasticity of PcG-repressed genes in terminal differentiated brain neurons of parkisonian mice. We show that acute administration of the dopamine precursor, L-DOPA, induces a remarkable increase in H3K27me3S28 phosphorylation. The induction of the H3K27me3S28p histone mark specifically occurs in medium spiny neurons expressing the dopamine D1 receptors and is dependent on Msk1 kinase activity and DARPP-32-mediated inhibition of protein phosphatase-1. Chromatin immunoprecipitation (ChIP) experiments showed that increased H3K27me3S28p was accompanied by reduced PcG binding to regulatory regions of genes. An analysis of the genome wide distribution of L-DOPA induced H3K27me3S28 phosphorylation by ChIP sequencing (ChIP-seq) in combination with expression analysis by RNA-sequencing (RNA-seq) showed that the induction of H3K27me3S28p correlated with increased expression of a subset of PcG repressed genes. We found that induction of H3K27me3S28p persisted during chronic L-DOPA administration to parkisonian mice and correlated with aberrant gene expression. We propose that dopaminergic transmission can activate PcG repressed genes in the adult brain and thereby contribute to long-term maladaptive responses including the motor complications, or dyskinesia, caused by prolonged administration of L-DOPA in Parkinsons disease. Overall design: 12 mice were used for RNAseq, 4 conditions, 3 mice per condition.
Dopamine signaling leads to loss of Polycomb repression and aberrant gene activation in experimental parkinsonism.
No sample metadata fields
View SamplesThe PLZF transcription factor is essential for osteogenic differentiation of hMSCs, however, its regulation and molecular function during this process is not fully understood. Here we revealed that the ZBTB16 locus encoding PLZF, is repressed by Polycomb (PcG) and H3K27me3 in naïve hMSCs. At the pre-osteoblast stage of differentiation, the locus lost PcG binding and H3K27me3, gained JMJD3 recruitment, and H3K27ac resulting in high expression of PLZF. Subsequently, PLZF was recruited to osteogenic enhancers, influencing H3K27 acetylation and expression of nearby genes important for osteogenic function. Furthermore, we identified a latent enhancer within the ZBTB16/PLZF locus itself that became active, gained PLZF, p300 and Mediator binding and looped to the promoter of the nicotinamide N-methyltransferase (NNMT) gene. The increased expression of NNMT correlated with a decline in SAM levels, which is dependent on PLZF and is required for osteogenic differentiation. Overall design: Effect of PLZF knockdown on osteogenic differentiation of hMSC (RNAseq)
PLZF targets developmental enhancers for activation during osteogenic differentiation of human mesenchymal stem cells.
Specimen part, Subject
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Loss of the histone methyltransferase EZH2 induces resistance to multiple drugs in acute myeloid leukemia.
Specimen part, Cell line
View SamplesHere, we analyzed global gene expression changes that were associated with drug resistance in Acute Myeloid Leukemia using the Affymetrix microarray platform.
Loss of the histone methyltransferase EZH2 induces resistance to multiple drugs in acute myeloid leukemia.
Specimen part, Cell line
View SamplesGlobal transcriptome patterns were performed using ORE1-IOE-2h (2h after Estradiol and Mock treatment) as well as transiently (6h) overexpressed Arabidopsis mesophyll cell protoplasts
NAC transcription factor ORE1 and senescence-induced BIFUNCTIONAL NUCLEASE1 (BFN1) constitute a regulatory cascade in Arabidopsis.
Specimen part, Treatment
View SamplesRenal artery stenosis (RAS) caused by narrowing of arteries is characterized by microvascular damage. Macrophages are implicated in repair and injury, but the specific populations responsible for these divergent roles have not been identified. Here, we characterized murine kidney F4/80+CD64+ macrophages in three transcriptionally unique populations. Using fate-mapping and parabiosis studies, we demonstrate that CD11b/cint are long-lived kidney-resident (KRM) while CD11chiMf, CD11cloMf are monocyte-derived macrophages. In a murine model of RAS, KRM self-renewed, while CD11chiMf and CD11cloMf increased significantly, which was associated with loss of peritubular capillaries. Replacing the native KRM with monocyte-derived KRM using bone marrow transplantation followed by RAS, amplified loss of peritubular capillaries. To further elucidate the nature of interactions between KRM and peritubular endothelial cells, we performed RNA-sequencing on flow-sorted macrophages from Sham and RAS kidneys. KRM showed a prominent activation pattern in RAS with significant enrichment in reparative pathways, like angiogenesis and wound healing. In culture, KRM increased proliferation of renal peritubular endothelial cells implying direct pro-angiogenic properties. Human homologs of KRM identified as CD11bintCD11cintCD68+ increased in post-stenotic kidney biopsies from RAS patients compared to healthy human kidneys, and inversely correlated to kidney function. Thus, KRM may play protective roles in stenotic kidney injury through expansion and upregulation of pro-angiogenic pathways Overall design: CD11chiMf Sham, n=3; CD11chiMf RAS, n=4; CD11cloMf Sham, n=3; CD11cloMf RAS, n=4; KRM Sham, n=4; KRM RAS, n=3;
Kidney-resident macrophages promote a proangiogenic environment in the normal and chronically ischemic mouse kidney.
Sex, Age, Specimen part, Cell line, Subject
View SamplesPDE4 inhibitors, which activate cAMP signaling by reducing cAMP catabolism, are known to induce apoptosis in B lineage chronic lymphocytic leukemia (CLL) cells but not normal human T cells. The explanation for such differential sensitivity remains unknown. Here, we report studies contrasting the response to PDE4 inhibitor treatment in CLL cells and normal human T and B cells.
Chronic lymphocytic leukemia and B and T cells differ in their response to cyclic nucleotide phosphodiesterase inhibitors.
No sample metadata fields
View SamplesLong-term pharmacological glucocorticoid therapy causes atrophy and hypofunction of the adrenal cortex. Following glucocorticoids withdrawal, a functional and anatomic regeneration take place, whose cellular and molecular mechanisms are poorly understood
Sonic Hedgehog and WNT Signaling Promote Adrenal Gland Regeneration in Male Mice.
Age, Specimen part
View SamplesThe goal of this study is to compare the transcriptome of the 2 MVT1 subpopulations in order to identify new genes and pathways that stands beyond the CD24+ aggressive phenotype Overall design: mRNA profiles of CD24- and CD24+ cells were generated by deep sequencing, in triplicate, using Illumina HiSeq 2500
Deep sequencing of mRNA in CD24(-) and CD24(+) mammary carcinoma Mvt1 cell line.
No sample metadata fields
View SamplesGenome instability is a potential limitation to the research and therapeutic application of induced pluripotent stem cells (iPSCs). Observed genomic variations reflect the combined activities of DNA damage, cellular DNA damage response (DDR), and selection pressure in culture. To understand the contribution of DDR on the distribution of copy number variations (CNVs) in iPSCs, we mapped CNVs of iPSCs with mutations in the central DDR gene ATM onto genome organization landscapes defined by genome-wide replication timing profiles. We show that following reprogramming the early and late replicating genome is differentially affected by CNVs in ATM deficient iPSCs relative to wild type iPSCs. Specifically, the early replicating regions had increased CNV losses during retroviral reprogramming. This differential CNV distribution was not present after later passage or after episomal reprogramming. Comparison of different reprogramming methods in the setting of defective DNA damage response reveals unique vulnerability of early replicating open chromatin to retroviral vectors.
Influence of ATM-Mediated DNA Damage Response on Genomic Variation in Human Induced Pluripotent Stem Cells.
Specimen part
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