Project description:We generated three kinds of genetically identical mouse reprogrammed cells: induced pluripotent stem cells (iPSCs), nuclear transfer embryonic stem cells (ntESCs) and iPSC-nt-ESCs that are established after successively reprogramming of iPSCs by nuclear transfer (NT). NtESCs show better developmental potential than iPSCs, whereas iPSC-nt-ESCs display worse developmental potential than iPSCs. We used microarrays to distinguish the gene expression differences among three pluriptoent stem cells and identified that imprinted genes had a similar expression pattern in iPSCs and iPSC-nt-ESCs.
Project description:We generated three kinds of genetically identical mouse reprogrammed cells: induced pluripotent stem cells (iPSCs), nuclear transfer embryonic stem cells (ntESCs) and iPSC-nt-ESCs that are established after successively reprogramming of iPSCs by nuclear transfer (NT). NtESCs show better developmental potential than iPSCs, whereas iPSC-nt-ESCs display worse developmental potential than iPSCs. We used microarrays to distinguish the gene expression differences among three pluriptoent stem cells and identified that imprinted genes had a similar expression pattern in iPSCs and iPSC-nt-ESCs. We sought to obtain genetic identical pluripotent stem cell lines in order to minimize genetic variations among different reprogrammed cells. To that end, we established a genetically homogenous secondary reprogramming system, in which mouse embryonic fibroblasts (MEFs) carrying doxycycline (dox)-inducible lentiviruses expressing Oct4, Sox2, Klf4 and c-Myc were isolated and used as donors for different reprogramming experiments. We generated iPSCs after plating MEFs in the presence of dox in ES culture conditions, and then derived ntESCs after transplantation of the nucleus from the same MEFs into enucleated oocyte. Furthermore, we successively reprogrammed iPSCs by means of NT and established a set of nt-iPSC lines. Pluripotent stem cells generated from different reprogramming strategies were for RNA extraction and hybridization on Affymetrix microarrays.
Project description:Pluripotent cells can be derived from somatic cells by either overexpression of defined transcription factors (resulting in induced pluripotent stem cells (iPSCs)) or by nuclear transfer or cloning (resulting in NT-ESCs). To determine whether cloning further reprograms iPSCs, we used iPSCs as donor cells in nuclear transfer experiments. An iPSC clone derived from tail-tip fibroblasts using adenoviral vectors was used as donor cell in nuclear transfer experiments. RNA was isolated from both parental iPSC clone and derivative NT-ESCs lines and analyzed.
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. RNA sequencing analysis was performed on a total of 12 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, 3 iPSC lines and their parental adult fibroblast cell line (derived from a type 1 diabetic subject); as well as 1 control embryonic stem cell (ESC) line.
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:Human pluripotent stem cells hold great potential for regenerative medicine, but available cell types have important limitations. While embryonic stem cells derived from fertilized embryos (IVF-ESCs) are considered the "gold standard" of pluripotency, they are allogeneic to potential recipients. Autologous induced pluripotent stem cells (iPSCs) are prone to epigenetic and transcriptional aberrations. To determine whether accumulation of such aberrations is intrinsic to somatic cell reprogramming or secondary to the reprogramming method, we generated a genetically matched collection of human IVF-ESCs, iPSCs, and ESCs derived by somatic cell nuclear transfer (SCNT; NT-ESCs), and subjected them to genome-wide genetic, epigenetic and transcriptional analyses. SCNT-based reprogramming is mediated by the full complement of oocyte cytoplasmic factors, thus closely recapitulating early embryogenesis. NT-ESCs and iPSCs derived from the same somatic donor cells contained comparable numbers of de novo copy number variations (CNVs), suggesting that the two reprogramming methods may not differ significantly in mutagenic or selective pressure. On the other hand, the DNA methylation and transcriptome profiles of NT-ESCs corresponded very closely to those of IVF-ESCs, while iPSCs differed markedly from IVF-ESCs and harbored residual DNA methylation patterns typical of parental fibroblasts, suggesting incomplete reprogramming. We conclude that human somatic cells can be faithfully reprogrammed to pluripotency by SCNT and are therefore ideal candidates for cell replacement therapies. 16 matched samples, two IVF-ESCs, five sendai produced iPSC lines, two retro-virus produced iPSC lines, four NT-ESCs, the parental fibroblast line, and the sperm and oocyte donor were genotyped using the Illumina Omni5, which interrogates 4.3 million SNPs across the human genome. Additionally, matched samples from a patient with Leigh syndrome, a NT-ESC line, three iPSC lines, and the parental fibroblast line were genotyped using the Illumina Omni5.
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.
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.
Project description:Human pluripotent stem cells hold great potential for regenerative medicine, but available cell types have important limitations. While embryonic stem cells derived from fertilized embryos (IVF-ESCs) are considered the "gold standard" of pluripotency, they are allogeneic to potential recipients. Autologous induced pluripotent stem cells (iPSCs) are prone to epigenetic and transcriptional aberrations. To determine whether accumulation of such aberrations is intrinsic to somatic cell reprogramming or secondary to the reprogramming method, we generated a genetically matched collection of human IVF-ESCs, iPSCs, and ESCs derived by somatic cell nuclear transfer (SCNT; NT-ESCs), and subjected them to genome-wide genetic, epigenetic and transcriptional analyses. SCNT-based reprogramming is mediated by the full complement of oocyte cytoplasmic factors, thus closely recapitulating early embryogenesis. NT-ESCs and iPSCs derived from the same somatic donor cells contained comparable numbers of de novo copy number variations (CNVs), suggesting that the two reprogramming methods may not differ significantly in mutagenic or selective pressure. On the other hand, the DNA methylation and transcriptome profiles of NT-ESCs corresponded very closely to those of IVF-ESCs, while iPSCs differed markedly from IVF-ESCs and harbored residual DNA methylation patterns typical of parental fibroblasts, suggesting incomplete reprogramming. We conclude that human somatic cells can be faithfully reprogrammed to pluripotency by SCNT and are therefore ideal candidates for cell replacement therapies. Duplicate cDNA libraries of two IVF-ESCs, three sendai produced iPSC lines, two retro-virus produced iPSC lines, four NT-ESCs, and the parental fibroblast line were sequenced using Illumina HiSeq 2000. The sequence reads were mapped to hg19 reference genome and hits that passed quality filters were analyzed for differential expression.