Transcription factor (TF)-induced reprogramming of somatic cells into induced pluripotent stem cells (iPSC) is associated with genome-wide changes in chromatin modifications. Polycomb-mediated histone H3 lysine-27 trimethylation (H3K27me3) has been proposed as a defining mark that distinguishes the somatic from the iPSC epigenome. Here, we dissected the functional role of H3K27me3 in TF-induced reprogramming through the inactivation of the H3K27 methylase EZH2 at the onset of reprogramming. Our results demonstrate that surprisingly the establishment of functional iPSC proceeds despite global loss of H3K27me3. iPSC lacking EZH2 efficiently silenced the somatic transcriptome and differentiated into tissues derived from the three germ layers. Remarkably, the genome-wide analysis of H3K27me3 in Ezh2 mutant iPSC cells revealed the retention of this mark on a highly selected group of Polycomb targets enriched for developmental regulators controlling the expression of lineage specific genes. Erasure of H3K27me3 from these targets led to a striking impairment in TF-induced reprogramming. These results indicate that PRC2-mediated H3K27 trimethylation is required on a highly selective core of Polycomb targets whose repression enables TF-dependent cell reprogramming.
Cell reprogramming requires silencing of a core subset of polycomb targets.
Specimen part
View SamplesACTH-dependent hypercortisolism caused by a pituitary adenoma [Cushings disease (CD)] is the most common cause of endogenous Cushings syndrome. CD is often associated with several morbidities, including hypertension, diabetes, osteoporosis/bone fractures, secondary infections, and increased cardiovascular mortality. While the majority (80%) of the corticotrophinomas visible on pituitary magnetic resonance imaging are microadenomas (MICs, <10 mm of diameter), some tumors are macroadenomas (MACs, 10 mm) with increased growth potential and invasiveness, exceptionally exhibiting malignant demeanor. In addition, larger and invasive MACs are associated with a significant increased risk of local complications, such as hypopituitarism and visual defects. Given the clinical and molecular heterogeneity of corticotrophinomas, the aim of this study was to investigate the pattern of genetic differential expression between MIC and MAC, including the invasiveness grade as a criterion for categorizing these tumors. In this study, were included tumor samples from patients with clinical, laboratorial, radiological, and histopathological diagnosis of hypercortisolism due to an ACTH-producing pituitary adenoma. Differential gene expression was studied using an Affymetrix microarray platform in 12 corticotrophinomas, classified as non-invasive MIC (n = 4) and MAC (n = 5), and invasive MAC (n = 3), according to modified Hardy criteria. Somatic mutations in USP8 were also investigated, but none of the patients exhibited USP8 variants. Differential expression analysis demonstrated that non-invasive MIC and MAC have a similar genetic signature, while invasive MACs exhibited a differential expression profile. Among the genes differentially expressed, we highlighted CCND2, ZNF676, DAPK1, and TIMP2, and their differential expression was validated through quantitative real-time PCR in another cohort of 15 non-invasive and 3 invasive cortocotrophinomas. We also identified potential biological pathways associated with growth and invasiveness, TGF- and G protein signaling pathways, DNA damage response pathway, and pathways associated with focal adhesion. Our study revealed a differential pattern of genetic signature in a subgroup of MAC, supporting a genetic influence on corticotrophinomas in patients with CD.
Transcriptome Analysis Showed a Differential Signature between Invasive and Non-invasive Corticotrophinomas.
Sex, Specimen part, Disease
View SamplesPolycomb proteins control proliferation and cellular transformation regulating DNA replication independently of cell cycle checkpoints
Polycomb proteins control proliferation and transformation independently of cell cycle checkpoints by regulating DNA replication.
Specimen part
View SamplesWe scored adrenocortical carcinomas and adenomas for abnormal beta-catenin staining, and sequenced the beta-catenin gene in some samples. We compared adrenocortincal carcinomas with and without abnormal beta-catenin staining and found many significant expression differences and significant results from enrichment testing. A similar comparison in the adenomas gave relatively few differences, and they did not correlate to differences found for the carcinomas. Abnormal beta-catenin staining was associated with mitotic rate and poorer patient survival in the carcinomas. In a second independent data set (given in a supplement) we again found beta-catenin associated with poor survival. The array data given is the same as GEO series GSE10927, with additional characteristics about beta-catenin, and new patient followup data. The analysis shown in a supplementary Excel file is also new.
Progression to adrenocortical tumorigenesis in mice and humans through insulin-like growth factor 2 and β-catenin.
Sex, Age
View SamplesThe widespread use of wireless devices during the last decades is rising the concern about the adverse health effects of the radiofrequency electromagnetic radiation (RF-EMR) emitted from these devices. Studies are targeting on unrevealing the underlying mechanisms of RF-EMR action. The contribution of the omics high throughput approaches is a prerequisite towards this direction. In the present work, C57BL/6 adult male mice were sham-exposed (nSE=8) or whole-body exposed (nExp=8) for 2h to GSM 1800 MHz mobile phone radiation at 11 V/m average electric field intensity, and the RF-EMR effects on the hippocampal lipidome and transcriptome profile were evaluated. The data analysis of the phospholipids fatty acid residues revealed that the levels of six fatty acids (16:0, 16:1 6+7c, 18:1 9c, 20:5 w3, SFA, MUFA) were significantly altered (p<0.05) in the exposed group. The microarray data analysis demonstrated that the expression of 178 genes changed significantly (p<0.05) between the two groups with a fold change cut off of 1.5. In general, the observed changes point out the attention to a membrane remodeling response of the tissue phospholipids after non-ionizing radiation exposure, reducing the Saturated Fatty Acids (SFA) and EPA omega-3 (20:5 w3) and increasing Monounsaturated Fatty Acids (MUFA) residues and in parallel reflect an impact to genes implicated in critical biological processes, as cell cycle, DNA replication and repair, cell death, cell signaling, nervous system development and function, immune system response, lipid metabolism and cancer
Hippocampal lipidome and transcriptome profile alterations triggered by acute exposure of mice to GSM 1800 MHz mobile phone radiation: An exploratory study.
Specimen part
View SamplesAnalysis of the transcriptome of mononuclear side population (SP) and main population (MP) cells of human fetal skeletal muscle from 12 human subjects of gestational age 14-18 weeks.
Regulation of myogenic progenitor proliferation in human fetal skeletal muscle by BMP4 and its antagonist Gremlin.
Specimen part
View SamplesLineage commitment during Embryonic Stem Cells (ESCs) differentiation is controlled not only by a gamut of transcription factors but also by epigenetic events, mainly histone deacetylation and promoter DNA methylation. Moreover, the DNA demethylation agent 5-Aza-2-deoxycytidine (AzadC) has been widely described in the literature as an effective chemical stimulus used to promote cardiomyogenic differentiation in various stem cell types; however, its toxicity and instability complicate its use. Thus, the purpose of this study was to examine the effects of zebularine, a stable and non-toxic DNA cytosine methylation inhibitor, on ESCs differentiation. Herein are the Affymetrix Expression data obtained from RNA of murine ESCs treated with zebularine.
Zebularine regulates early stages of mESC differentiation: effect on cardiac commitment.
Specimen part, Cell line, Treatment
View SamplesFunctional analysis of ABCB5 in A375 and G3361 melanoma cells, by comparing stably-transfected controls to ABCB5-shRNA-targeted cells.
ABCB5 maintains melanoma-initiating cells through a proinflammatory cytokine signaling circuit.
Specimen part, Cell line
View SamplesTo find BMAL1-regulated genes in mice pituitary gland we performed a differential microarray from wild-type vs Bmal1-/- knock-out mice
Chromatin remodeling as a mechanism for circadian prolactin transcription: rhythmic NONO and SFPQ recruitment to HLTF.
Sex, Specimen part
View SamplesMitochondrial DNA (mtDNA) mutations are maternally inherited and are associated with a broad range of debilitating and fatal diseases. Assisted reproductive technologies designed to uncouple the inheritance of mtDNA from nuclear DNA may enable women who carry mtDNA mutations to have a genetically related child with a greatly reduced risk of disease. Here we report for the first time that pronuclear transplantation (PNT) between normally fertilised human zygotes provides an effective approach to preventing transmission of mtDNA disease. We found that the procedures previously used to perform PNT between abnormally fertilized human zygotes are highly inefficient when applied to those that undergo normal fertilization. We have therefore developed an alternative approach based on transplanting PN shortly after completion of the second meiotic division rather than shortly before onset of the first mitosis. This approach promotes highly efficient development to the blastocyst stage without affecting nuclear genome integrity. Furthermore, the expression profile of genes encoded by the nuclear and mitochondrial genomes was indistinguishable from unmanipulated control embryos. Importantly, levels of mtDNA transferred with the nuclear genome are below the threshold for mtDNA disease. Together these data indicate that transplantation of pronuclei early in the first cell cycle holds promise as a safe and effective approach to preventing transmission of mtDNA disease. Overall design: Single-Cell RNA-seq analysis of embryos generated by pronuclear transfer and unmanipulated control embryos The relationship between single cell samples and the embryo from which they were derived is indicated in the sample ''characteristics: sample type'' field.
Towards clinical application of pronuclear transfer to prevent mitochondrial DNA disease.
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