Project description:Transcription factor-mediated reprogramming yields induced pluripotent stem cells (iPSC) by erasing tissue specific methylation and re-setting DNA methylation status to an embryonic stage. We compared bona fide human iPSC derived from umbilical cord blood (CB) and neonatal keratinocytes (K). Through both incomplete erasure of tissue specific methylation and de novo tissue specific methylation, CB-iPSC and K-iPSC are distinct in genome-wide DNA methylation profiles. Functionally, CB-iPSC displayed better blood formation in vitro, whereas K-iPSC differentiated better to a keratinocyte fate, implying that the tissue of origin needs to be considered in future therapeutic applications of human iPSCs. We performed gene expression and global DNA methylation profiling on iPS and the source somatic cell types to search for evidence of epigenetic memory. We performed gene expression profiling to identify genes differentially expressed between keratinocytes and cord blood, and from induced pluripotent stem cells from these somatic tissues.
Project description:Genome-wide analysis of histone modification (H2AZ, H3K27ac, H3K27me3, H3K36me3, H3K4me1, H3K4me2, H3K4me3 and H3K9me3), protein-DNA binding (TAF1, P300, Pou5f1 and Nanog), cytosine methylation and transcriptome data in mouse and human ES cells and pig iPS cells We generated histone modification data (H2AZ, H3K27ac, H3K27me3, H3K36me3, H3K4me1, H3K4me2, H3K4me3 and H3K9me3) and protein-DNA binding data (TAF1, P300, Pou5f1 and Nanog) using Chromatin Immunoprecipitation followed by short sequencing (ChIP-seq), cytosine methylation data using methylated DNA immunoprecipitation followed by sequencing (MeDIP-seq) and DNA digestion by methyl-sensitive restriction enzymes followed by sequencing (MRE-seq), transcriptome data with RNA short sequencing (RNA-seq) in human embryonic stem cells, mouse embryonic stem cells, pig induced pluripotent stem cells and mouse embryonic stem cells under activin-A-induced-differentiation. Examination of 8 histone modifications, 4 protein-DNA binding, cytosine methylation and transcriptome in human embryonic stem cells, mouse embryonic stem cells, pig induced pluripotent stem cells and mouse embryonic stem cells under activin-A-induced-differentiation.
Project description:Human pluripotent stem cells can be derived from somatic cells by forced expression of defined factors, and more recently by nuclear-transfer into human oocytes, revitalizing a debate on whether one reprogramming approach might be advantageous over the other. Here we compared the genetic and epigenetic stability of human nuclear-transfer embryonic stem cell (NT-ESC) lines and isogenic induced pluripotent stem cell (iPSC) lines, derived from the same somatic cell cultures of fetal, neonatal and adult origin. Both cell types shared similar genome-wide gene expression and DNA methylation profiles. Importantly, NT-ESCs and iPSCs have comparable numbers of de novo coding mutations but significantly higher than parthenogenetic ESCs. Similar to iPSCs NT-ESCs displayed clone- and gene-specific aberrations in DNA methylation and allele-specific expression of imprinted genes, similarly to iPSCs. The occurrence of these genetic and epigenetic defects in both NT-ESCs and iPSCs suggests that they are inherent to reprogramming, regardless of the underlying technique. Genome-wide DNA methylation profiling by Illumina Infinium HumanMethylation 450K Beadchip was performed on a total of 21 human cell lines, including: an isogenic set of 3 nuclear-transfer embryonic stem cell (NT-ESC) lines, 2 RNA-reprogrammed induced pluripotent stem cell (iPSC) lines and their parental neonatal fibroblast cell line; an isogenic set of 1 NT-ESC line, 6 iPSC lines and their parental adult fibroblast cell line (derived from a type 1 diabetic subject); as well as 7 control embryonic stem cell (ESC) lines.
Project description:Genome wide DNA methylation profiling of normal human embryonic stem cells, induced pluripotent stem cells, and somatic cells. The Illumina Infinium 27k Human DNA methylation Beadchip v1.2 was used to obtain DNA methylation profiles across approximately 27,000 CpGs in 5 normal hESCs, 15 hiPSCs (vector-containing and vector-free), and 5 somatic cells. Bisulphite converted DNA from the 25 samples were hybridised to the Illumina Infinium 27k Human Methylation Beadchip v1.2
