Project description:We performed 5hmC DNA Immunoprecipitation followed high-throughput sequencing using R1 ESCs, OT ESCs, TSKM ESCs, Day3 TSKM and OSKM induction cells. We compared the profiling of 5-hydroxymethylcytosine modifications in these different cell lines. We found that: the TSKM and OT iPSCs shared similar 5hmC modification pattern while apart from that of R1 ESCs. However the comparison based on the gene promoter (-1000/+500 of gene’s TSS) showed less differences. The TSKM 2nd induction samples were quite like each other and have shared the basic pattern with traditional OSKM 2nd sample. However comparison based on the gene promoter showed sharp increase. Moreover higher enrichment of 5hmC on the distal enhancer of Oct4 was specifically detected in Day 3 TSKM 2nd cells as well as TSKM and OT iPSCs, which might be helpful for us to study the Tet1-mediated somatic reprogramming. Examination of 5-hydroxymethylcytosine modifications in 5 different cell lines.
Project description:Mammalian somatic cells can be directly reprogrammed into induced pluripotent stem cells (iPSCs) by introducing defined sets of transcription factors. Somatic cell reprogramming involves epigenomic reconfiguration, conferring iPSCs with characteristics similar to embryonic stem (ES) cells. Human ES cells contain 5-hydroxymethylcytosine (5hmC), which is generated though the oxidation of 5-methylcytosine (5mC) by the TET family of enzymes. Here we show that 5hmC level increases significantly during reprogramming due to the activation of TET1. During this process, dynamic genome-wide 5hmC modification occurs across the genome with more modifications at telomere-proximal regions. Compared with hES cells, we found iPS cells tend to form large-scale (100kb-1.3Mb) aberrant reprogramming hotspots in subtelomeric regions, most of which display incomplete hydroxymethylation. Strikingly, these 5hmC aberrant hotspots largely coincide (>80%) with previously reported aberrant non-CG methylation regions. Our results suggest that 5hmC modification could play important roles during reprogramming to pluripotency, and contribute to the differences between iPSCs and hESCs. we generated comprehensive genome-wide profiles of 5hmC in somatic cells, iPS cell lines derived from a variety of origins, and multiple hES cell lines.
Project description:This SuperSeries is composed of the following subset Series: GSE32050: 5-hydroxymethylcytosine-mediated epigenetic dynamics during neurodevelopment and aging [5hmC Capture and Seq] GSE32187: 5-hydroxymethylcytosine-mediated epigenetic dynamics during neurodevelopment and aging [mRNA profiling] Refer to individual Series
Project description:We have sequenced miRNA libraries from human embryonic, neural and foetal mesenchymal stem cells. We report that the majority of miRNA genes encode mature isomers that vary in size by one or more bases at the 3’ and/or 5’ end of the miRNA. Northern blotting for individual miRNAs showed that the proportions of isomiRs expressed by a single miRNA gene often differ between cell and tissue types. IsomiRs were readily co-immunoprecipitated with Argonaute proteins in vivo and were active in luciferase assays, indicating that they are functional. Bioinformatics analysis predicts substantial differences in targeting between miRNAs with minor 5’ differences and in support of this we report that a 5’ isomiR-9-1 gained the ability to inhibit the expression of DNMT3B and NCAM2 but lost the ability to inhibit CDH1 in vitro. This result was confirmed by the use of isomiR-specific sponges. Our analysis of the miRGator database indicates that a small percentage of human miRNA genes express isomiRs as the dominant transcript in certain cell types and analysis of miRBase shows that 5’ isomiRs have replaced canonical miRNAs many times during evolution. This strongly indicates that isomiRs are of functional importance and have contributed to the evolution of miRNA genes
Project description:ATAC-seq samples from 2 species and 2 cell types were generated to study cis-regulatory element evolution. Briefly, previously generated urinary stem cell derived iPS-cells (Homo sapiens) of 2 human individuals and fibroblast derived cynomolgus macaque iPSCs (Macaca fascicularis) of 2 individuals (Geuder et al. 2021) were differentiated to neural progenitor cells via dual-SMAD inhibition as three-dimensional aggregation culture (Chambers et al. 2009; Ohnuki et al. 2014). The NPC lines were cultured in NPC proliferation medium and passaged 2 - 4 times until they were dissociated and subjected to ATAC-seq together with the respective iPSC clones. ATAC-seq libraries were generated using the Omni-ATAC protocol (Corces et al. 2017) with minor modifications.
Project description:We performed 5hmC/5mC DNA Immunoprecipitation followed high-throughput sequencing using the cell sample along the whole TSKM secondary reprogramming system. The TSKM 0D is the fibroblasts deried from TSKM-iPS mouse as the starting cells of the reprogramming.The intermediate cells is 3-days induced cells which are refered as TSKM 3D cells, and the final reprogrammed cells is the iPS cells with full pluripotency driven from this secondary system. We compared the profiling of 5-hydroxymethylcytosine and 5-methylcytosine modifications in these different cell lines. We found that: a widespread accompanying increase of 5hmC and 5mC at TSS and ES-active regulation regions followed by 5mC-5hmC pattern switch. Taking the advantage of the newly established TSKM secondary reprogramming system, the epigenetic remodeling and regulation mechanisms can be further investigated to advance our understanding of the epigenetic barriers and decipher the dynamic mechanism in somatic cell reprogramming. Examination of 5-hydroxymethylcytosine/5-methylcytosine modifications in a Tet1-mediated secondary reprogramming system