Project description:This SuperSeries is composed of the following subset Series: GSE30652: Recurrent Variations in DNA Methylation in Human Pluripotent Stem Cells and their Differentiated Derivatives [Illumina HT12v3 Gene Expression] GSE30653: Recurrent Variations in DNA Methylation in Human Pluripotent Stem Cells and their Differentiated Derivatives [Illumina Infinium 27K DNA Methylation] GSE31848: Recurrent Variations in DNA Methylation in Human Pluripotent Stem Cells and their Differentiated Derivatives [Illumina Infinium 450K DNA Methylation] Refer to individual Series
Project description:Recurrent Variations in DNA Methylation in Human Pluripotent Stem Cells and their Differentiated Derivatives [Illumina Infinium 450K DNA Methylation]
Project description:Recurrent Variations in DNA Methylation in Human Pluripotent Stem Cells and their Differentiated Derivatives [Illumina Infinium 27K DNA Methylation]
Project description:Recurrent Variations in DNA Methylation in Human Pluripotent Stem Cells and their Differentiated Derivatives [Illumina HT12v3 Gene Expression]
Project description:DNA methylation is an epigenetic modification that specifies the basic state of pluripotent stem cells and regulates the developmental transition from stem cells to various cell types. In flowering plants, the shoot apical meristem (SAM) contains a pluripotent stem cell population which generates the aerial part of plants including the germ cells. Under appropriate conditions, the SAM undergoes a developmental transition from a leaf-forming vegetative SAM to an inflorescence- and flower-forming reproductive SAM. While SAM characteristics are largely altered in this transition, the complete picture of DNA methylation remains elusive. Here, by analyzing whole-genome DNA methylation of isolated rice SAMs in the vegetative and reproductive stages, we found that methylation at CHH sites is kept high, particularly at transposable elements (TEs), in the vegetative SAM relative to the differentiated leaf, and increases in the reproductive SAM via the RNA-dependent DNA methylation pathway. We also found that half of the TEs that were highly methylated in gametes had already undergone CHH hypermethylation in the SAM. Our results indicate that changes in DNA methylation begin in the SAM long before germ cell differentiation to protect the genome from harmful TEs.
Project description:Pluripotent stem cells, including human embryonic stem (hES) and induced pluripotent stem (hiPS) cells, have been regarded as useful sources for cell?based transplantation therapy. However immunogenicity of the cells remains the major determinant for successful clinical application. We report the examination of several hES cell lines (NTU1 and H9), hiPS cell lines, and their derivatives (including stem cell?derived hepatocytes) for the expression of major histocompatibility complex (MHC), natural killer (NK) cell receptor (NKp30, NKp44, NKp46) ligand, immune?related genes, human leukocyte antigen (HLA) haplotyping, and the effects in functional mixed lymphocyte reaction (MLR). Flow cytometry showed lower levels (percentages and fluorescence intensities) of MHC class I (MHC?I) molecules, β2?microglobulin and HLA?E in undifferentiated stem cells, but the levels were increased after co?treatment with interferon gamma and/or in vitro differentiation. Antigen presenting cell markers (CD11c, CD80 and CD86) and MHC?II (HLA?DP, DQ and DR) remained low throughout the treatments. Recognitions of stem cells/derivatives by NK lysis receptors were lower or absent. Activation of responder lymphocytes was significantly lower by undifferentiated stem cells than by allogeneic lymphocytes in MLR, but differentiated NTU1 hES cells induced a cell number?dependent lymphocyte proliferation comparable with that by allogeneic lymphocytes. Interestingly activation of lymphocytes by differentiated hiPS cells or H9 cells became blunted at higher cell numbers. Real?time RT?PCR showed significant differential expression of immune privilege genes (TGF?β2, Arginase 2, Indole 1, GATA3, POMC, VIP, CALCA, CALCB, IL?1RN, CD95L, CR1L, Serpine 1, HMOX1, IL6, LGALS3, HEBP1, THBS1, CD59 and LGALS1) in pluripotent stem cells/derivatives when compared to somatic cells. It is concluded that pluripotent stem cells/derivatives are predicted to be immunogenic, though evidences suggest some levels of potential immune privilege. In addition, differential immunogenicity may exist between different pluripotent stem cell lines and their derivatives
Project description:Here we performed genome-wide RNA-seq and Reduced Representation Bisulfite Sequencing (RRBS-seq) in isogenic human induced pluripotent stem cells (iPSCs) and somatic cell nuclear transfer-derived embryonic stem cells (nt-ESCs), genetically matched in vitro fertilization-derived ESCs (IVF-ESCs), and their respective differentiated cells (cardiomyocytes and endothelial cells). We generated the transcriptome and DNA methylome map in human pluripotent stem cells and their differentiated cells with single-nucleotide resolution. We compared the genetic (genetic makeup) and epigenetic (reprogramming approach) influence on the gene expression and DNA methylation profiles and found that genetic composition is the major contributor of the transcriptional and epigenetic variances observed in the undifferentiated and differentiated cells originated from different reprogramming mechanisms.
Project description:The role of R-loops, three-stranded nucleic acid structures harboring DNA:RNA hybrids, in regulating cell fate decisions remains elusive. Using an isogenic human stem cell platform, we systematically characterized R-loops, DNA methylation, histone modifications, and chromatin accessibility in pluripotent cells and their lineage-differentiated derivatives. We found that R-loops initially formed co-transcriptionally at pluripotency genes in pluripotent cells. Upon differentiation into neural, mesenchymal, endothelial, and smooth muscle lineages, R-loops and repressive chromatin marks increased synergistically on pluripotency genes and undesired lineage genes, while new R-loops formed co-transcriptionally to activate lineage determination genes. In reprogrammed pluripotent cells, features of epigenetic memory and aberrant gene expression were initially present in regions highly enriched with R-loops, but became resolved with serial passaging. Our analysis defines a multi-faceted role of R-loops in cell fate determination and adds an additional layer of epigenetic control of cell state changes and cell fate memory.
Project description:DNA methylation plays an important role in development and disease. The primary sites of DNA methylation in vertebrates are cytosines in the CpG dinucleotide context, which account for roughly three quarters of the total DNA methylation content in human and mouse cells. While the genomic distribution, inter-individual stability and functional role of CpG methylation are reasonably well understood, little is known about DNA methylation targeting CpA, CpC and CpT dinucleotides. Here we report a comprehensive analysis of non-CG methylation in 72 genome-scale DNA methylation maps across human pluripotent and differentiated cell types. We confirm non-CG methylation to be predominant in pluripotent cell types and observe an expected decrease upon differentiation and near complete absence in various differentiated cells. Our data highlight that non-CG methylation is highly variable and shows little conservation between different pluripotent cell lines. While we show a strong correlation of non-CG methylation and DNMT3 expression levels we find a statistical independence of non-CG methylation from pluripotency associated gene expression. Finally, non-CG methylation appears to be spatially correlated with CpG methylation. In summary these results contribute further to our understanding of DNA methylation in human cells and help clarify previous observations using a large representative sample set. Examination of nonCG DNA methylation patterns in pluripotent and differentiated cells