In proliferating cells, where most Polycomb repressive complex 2 (PRC2) studies have been performed, gene repression is associated with PRC2 trimethylation of H3K27 (H3K27me3). However, it is uncertain whether PCR2 writing of H3K27me3 is mechanistically required for gene silencing. Here we studied PRC2 function in postnatal mouse cardiomyocytes, where the paucity of cell division obviates bulk H3K27me3 rewriting after each cell cycle. EED (Embryonic Ectoderm Development) inactivation in the postnatal heart (Eed CKO ) caused lethal dilated cardiomyopathy. Surprisingly, gene upregulation in Eed CKO was not coupled with loss of H3K27me3. Rather, the activating histone mark H3K27ac increased. EED interacted with histone deacetylases (HDACs) and enhanced their catalytic activity. HDAC overexpression normalized Eed CKO heart function and expression of derepressed genes. Our results uncovered a non-canonical, H3K27me3-independent EED repressive mechanism that is essential for normal heart function. Our results further illustrate that organ dysfunction due to epigenetic dysregulation can be corrected by epigenetic rewiring.
EED orchestration of heart maturation through interaction with HDACs is H3K27me3-independent.
Specimen part
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A systematic analysis of the skeletal muscle miRNA transcriptome of chicken varieties with divergent skeletal muscle growth identifies novel miRNAs and differentially expressed miRNAs.
Specimen part
View SamplesThe genetic closeness and divergent muscle growth rates of broilers and layers make them great models for myogenesis study. In order to discover the molecular mechanisms determining the divergent muscle growth rates and muscle fiber sizes in different chicken lines, we systematically identified differentially expressed genes between broilers and layers during muscle development (embyonic day 10, 12, 14 and 18) by microarray hybridization experiment.
A systematic analysis of the skeletal muscle miRNA transcriptome of chicken varieties with divergent skeletal muscle growth identifies novel miRNAs and differentially expressed miRNAs.
Specimen part
View SamplesThe molecular explanation for tamoxifen serving as a breast cancer treatment but displaying partial estrogenic in the uterus is not known. Previously, we reported that differential promoter context and cofactor recruitment contribute to the tissue specificity of tamoxifen. Here, we investigated the genomic basis for the partial oestrogenic activity of tamoxifen in the endometrium. We showed that tamoxifen not only affects the rate of transcription of oestrogen target genes but also targets a unique set of genes. Since oestrogen and tamoxifen are both able to bind to oestrogen receptors (ERs) and because both promote endometrial carcinogenesis, we hypothesized that the molecular effectors for ERs in endometrial carcinogenesis most likely reside in genes that are commonly targeted by oestrogen and tamoxifen. Among those target genes, we identified a paired-box gene PAX2 that is critically involved in cell proliferation and carcinogenesis in the endometrium. Our experiments also demonstrated that PAX2 is activated by oestrogen and tamoxifen in endometrial carcinomas but not in normal endometrium, and this activation is associated with cancer-linked hypomethylation of the PAX2 promoter.
Hypomethylation-linked activation of PAX2 mediates tamoxifen-stimulated endometrial carcinogenesis.
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View SamplesThrough H3K27me3 and H3K27ac ChIP-seq and microarray data in wile-tpye (WT) and EED-knockout (CKO) mouse cardiomyocytes, we unexpectedly uncovered a novel mechanism of PRC2-mediated gene repression. EED inactivation in the postnatal heart (EEDCKO) caused progressive, lethal dilated cardiomyopathy, with upregulation of components of the slow-twitch muscle gene program. Surprisingly, upregulation of these genes was not associated with their loss of H3K27me3, but rather with their gain of H3K27 acetylation (H3K27ac), an activating histone mark4,5. Moreover, re-expression of EED in juvenile hearts rescued heart function and normalized H3K27ac, but not H3K27me3.
No associated publication
Specimen part
View SamplesInduced pluripotent stem (iPS) cells can be generated from somatic cells by transduction with several transcription factors in both mouse and human. However, direct reprogramming in other species has not been reported. Here, we established an efficient method to generate monkey iPS cells from fibroblasts by retrovirus-mediated introduction of the four monkey transcription factors OCT4 (POU5F1), SOX2, KLF4, and c-MYC. The monkey iPS cells displayed ES-like morphology, expressed ES cell-marker genes, shared similar global gene profiles and methylation status in the OCT4 promoter to those of monkey ES cells, and possessed the ability to differentiate into three germ layers in vitro and in vivo. Our results suggest that the mechanism of direct reprogramming is conserved among species. The efficient generation of monkey iPS cells will allow investigation of the feasibility of therapeutic cloning in primate model with various diseases.
Generation of induced pluripotent stem cells from adult rhesus monkey fibroblasts.
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View SamplesTo examine the expression patterns of human miR-22-responsive transcripts in estrogen receptor alpha positive cell line MCF7, we transfected miR-22 duplex or negative control RNA duplex into MCF7 cells. Gene expression patterns were then evaluated using Affymetrix Human Genome U133 Plus 2.0 Array microarrays.
No associated publication
Specimen part, Cell line
View SamplesBackground and aim: Human Induced pluripotent stem (iPS) cells have been derived from dermal broblasts, keratinocytes and blood cells by ectopic expression of defined transcription factors.15 Application of this approach in human cells would have enormous potential and generate patient-specific pluripotent stem cells to accelerate the implementation of stem cells for clinical treatment of degenerative diseases. In the present study, we investigated whether genetically marked human mesenchymal cells of gut mesentery may give rise to iPS cells.
Generation of human-induced pluripotent stem cells from gut mesentery-derived cells by ectopic expression of OCT4/SOX2/NANOG.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Cell-Cycle-Targeting MicroRNAs as Therapeutic Tools against Refractory Cancers.
Specimen part, Cell line
View SamplesTo identify the genes differently expressed in the epithelium and the stromal of Benign Prostatic Hyperplasia (BPH), we collect the epithelium and the stromal from the patients with benign prostatic hyperplasia by laser micro-dissection. And then, Affymetrix HG-U133_Plus_2 gene-chip was used to detect and compare the expression level of genes.
No associated publication
Disease, Disease stage
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