Project description:We surveyed RNA-Seq data to identify those TEs that are transcriptionally active uniquely in human pluripotent cells. We identified one endogenous retrovirus (HERV-H) family, uniquely found in primates as being unusually abundant in the transcriptome. The microarray data provided is to support our human naive cell hypothesis. Total of 18 samples of the human ESC line H9 were analyzed for gene expression.
Project description:We surveyed RNA-Seq data to identify those TEs that are transcriptionally active uniquely in human pluripotent cells. We identified one endogenous retrovirus (HERV-H) family, uniquely found in primates as being unusually abundant in the transcriptome. Poly(A)+ RNA extraction and further sequencing library construction was done for two types of cells (iPS, HFF-1) and hiPSC-derived embryoid bodies following Illumina TruSeq RNA Sample Preparation Kit protocol, which was further sequenced on Illumina HiSeq machine with single-end 101 cycles.
Project description:The de novo DNA methyltransferase DNMT3B functions in establishing DNA methylation patterns during development. We performed RNAi knockdown of DNMT3B in human embryonic stem cells (ESCs) in order to investigate the mechanistic contribution of DNMT3B on DNA methylation and early neuronal differentiation. Genome-wide analyses of DNA methylation by MethylC-seq identified novel regions of hypomethylation in the DNMT3B knockdowns along the X chromosome as well as pericentromeric regions, rather than changes to specific dysregulated gene promoters. While DNMT3B was not required for early neuroepithelium specification, DNMT3B deficient neuroepithelium exhibited accelerated maturation with earlier expression of mature neuronal markers (such as NEUROD1) and early neuronal regional specifiers (such as neural crest) relative to normal ESCs. Our results suggest that DNMT3B mediates large-scale methylation patterns in human ESCs and that DNMT3B deficiency alters the timing of neuronal maturational differentiation in human neuronal cultures. Examined DNA methylation in human embryonic stem cells, both with and without DNMT3B knockdown
Project description:5-methylcytosine (5-mC) can be oxidized to 5-hydroxymethylcytosine (5-hmC). Genome-wide profiling of 5-hmC thus far indicated 5-hmC may not only be an intermediate form of DNA demethylation but could also constitute an epigenetic mark per se. We describe a cost-effective and selective method to detect both the hydroxymethylation and methylation status of cytosines in more than 1.8 million MspI sites in the human genome. This method involves the selective glucosylation of 5-hmC residues, short-sequence tag generation and high-throughput sequencing. We tested this method by screening H9 human embryonic stem cells and their differentiated embroid body cells, and found that differential hydroxymethylation preferentially occur in bivalent genes during cellular differentiation. Especially, our results support hydroxymethylation can regulate key transcription regulators with bivalent marks through demethylation and affect cellular decision on choosing active or inactive state of these genes upon cellular differentiation. In order to explore the role of methylation and hyroxymethylation in regulating gene expression upon cellular differentiation to EBs, we examined the gene expression level in H9 human embryonic stem cells and their differentiated embroid body cells by Digital gene expression (DGE), respectively.
Project description:Many studies have compared the genetic and epigenetic profiles of human induced pluripotent stem cells (hiPSCs) to human embryonic stem cells (hESCs) and yet the picture remains unclear. To address this, we derived a population of neural precursor cells (NPCs) from the H1 (WA01) hESC line and generated isogenic iPSC lines by reprogramming. The gene expression and methylation profile of three lines were compared to the parental line and intermediate NPC population. We found no gene probe with expression that differed significantly between hESC and iPSC samples under undifferentiated or differentiated conditions. Analysis of the global methylation pattern also showed no significant difference between the two PSC populations. Both undifferentiated populations were distinctly different from the intermediate NPC population in both gene expression and methylation profiles. One point to note is that H1 is a male line and so extrapolation to female lines should be cautioned. However, these data confirm our previous findings that there are no significant differences between hESCs and hiPSCs at the gene expression or methylation level. 12 samples: 1 human NPC, 5 human ESC (UNDIFF), 6 human iPSC (UNDIFF)
Project description:The tumorigenicity of human pluripotent stem cells (hPSCs) is a major safety concern for their application in regenerative medicine. Here we identify the tight-junction protein Claudin-6 as a specific cell surface marker of hPSCs that can be used to selectively remove Claudin-6-positive cells from mixed cultures. We show that Claudin-6 is absent in adult tissues but highly expressed in undifferentiated cells, where it is dispensable for hPSC survival and self-renewal. We use three different strategies to remove Claudin-6-positive cells from mixed populations: an antibody against Claudin-6; a cytotoxin-conjugated antibody that selectively targets undifferentiated cells; and clostridium perfringens enterotoxin, a toxin that binds several Claudins, including Claudin-6, and efficiently kills undifferentiated cells, thus eliminating the tumorigenic potential of hPSC-containing cultures. This work provides a proof of concept for the use of Claudin-6 to eliminate residual undifferentiated hPSCs from culture, highlighting a strategy that may increase the safety of hPSC-based cell therapies. total RNA was isolated from teratomas or from embryoid bodies differentiated from human induced pluripotent stem cells
Project description:Comparing gene expressing profile of human embryonic stem cells and neuroepithelial cells differentiated from human embryonic stem cells.
Project description:5-methylcytosine (5-mC) can be oxidized to 5-hydroxymethylcytosine (5-hmC). Genome-wide profiling of 5-hmC thus far indicated 5-hmC may not only be an intermediate form of DNA demethylation but could also constitute an epigenetic mark per se. We describe a cost-effective and selective method to detect both the hydroxymethylation and methylation status of cytosines in more than 1.8 million MspI sites in the human genome. This method involves the selective glucosylation of 5-hmC residues, short-sequence tag generation and high-throughput sequencing. We tested this method by screening H9 human embryonic stem cells and their differentiated embroid body cells, and found that differential hydroxymethylation preferentially occur in bivalent genes during cellular differentiation. Especially, our results support hydroxymethylation can regulate key transcription regulators with bivalent marks through demethylation and affect cellular decision on choosing active or inactive state of these genes upon cellular differentiation. We developed a cost-effective and selective method to detect both the hydroxymethylation and methylation status of cytosines in more than 1.8 million MspI sites in the human genome. In this method, we took advantage of the differential enzymatic sensitivities of the isoschizomers MspI and HpaII. HpaII cleaves only a completely unmodified site, any modification at either cytosine blocks the cleavage, while MspI recognizes and cleaves both 5-mC and 5-hmC, but not the newly discovered 5-formylcytosine (5-fC) and 5-carboxylcytosine (5-caC). Furthermore, beta-glucosyltransferase (beta-GT) can transfer a glucose to the hydroxyl group of 5-hmC and generate beta-glucosyl-5-hydroxymethylcytosine (5-ghmC) that blocks MspI digestion. Thus, either by combining beta-GT treatment with MspI digestion or simply applying MspI/HpaII digestion, short sequence tags generated can be used for inferring hydroxymethylation or methylation status in around 1.8 million cytosine sites in the human genome. We tested this method by screening H9 human embryonic stem cells and their differentiated embroid body cells.
Project description:Stable Pax6 and Luciferase knockdown human embryonic stem cell lines (H9) were made through lentiviral infection. Two different Pax6 RNAi lines and two Luciferase RNAi lines were then differentiated to neuroectoderm cells for 6 days. mRNA pooled from these two individual lines were then subjected to gene expression profiling analysis using affymetrix U133 plus 2.0 array.