Project description:Pluripotency can be induced in murine and human fibroblast by transduction of four transcription factors (Oct4, Sox2, Klf4 and c-Myc). Previously we reported that two factors (Oct4 and Klf4) are sufficient for reprogramming adult mouse neural stem cells (NSCs) to a pluripotent state. However, although NSCs endogenously express the factors Sox2, c-Myc, and Klf4, our previous report does not elucidate why exogenous expression of either Klf4 or c-Myc is still required for reprogramming. Here we report that exogenous expression of Oct4 is sufficient to generate one-factor induced pluripotent stem (1F iPS) cells without any oncogenic factors, such as c-Myc and Klf4, from mouse adult NSCs, which endogenously express Sox2, c-Myc, and Klf4, and also intermediate reprogramming markers alkaline phosphatase (AP), stage-specific embryonic antigen-1 (SSEA-1). These results extend our previous report proposing that somatic cells can be reprogrammed to a pluripotent state with a reducing number of reprogramming factors when the complementing factors are endogenously expressed in the somatic cells. Experiment Overall Design: 10 hybridizations in total. Experiment Overall Design: NSC-derived iPS cells by one-factor (Oct4) in triplicate: Experiment Overall Design: - NSC_1F_iPS_1 Experiment Overall Design: - NSC_1F_iPS_2 Experiment Overall Design: - NSC_1F_iPS_3 Experiment Overall Design: One-factor (Oct4) iPS cell-derived NSC in triplicate: Experiment Overall Design: - 1F_iPS_NSC_1 Experiment Overall Design: - 1F_iPS_NSC_2 Experiment Overall Design: - 1F_iPS_NSC_3 Experiment Overall Design: Neural stem cell (NSC) derived from brain of OG2/Rosa26 mice: Experiment Overall Design: - NSC_1 Experiment Overall Design: - NSC_2 Experiment Overall Design: - NSC_3 Experiment Overall Design: - NSC_4
Project description:We describe a so far uncharacterized, embryonic and self-renewing Neural Plate Border Stem Cell (NBSC) population with the capacity to differentiate into central nervous and neural crest lineages. NBSCs can be obtained by neural transcription factor-mediated reprogramming (BRN2, SOX2, KLF4, and ZIC3) of human adult dermal fibroblasts and peripheral blood cells (induced Neural Plate Border Stem Cells, iNBSCs) or by directed differentiation from human induced pluripotent stem cells (NBSCs). Moreover, human (i)NBSCs share molecular and functional features with an endogenous NBSC population isolated from neural folds of E8.5 mouse embryos. Upon differentiation, iNBSCs give rise to either (1) radial glia-type stem cells, dopaminergic and serotonergic neurons, motoneurons, astrocytes, and oligodendrocytes or (2) cells from the neural crest lineage. Here we provide array-based methylation data of iNBSCs reprogrammed from adult dermal fibroblasts (ADF), iPSC-derived NBSCs and adult dermal fibroblasts. The data provided demonstrate robust changes in the methylation landscape after reprogramming of human adult dermal fibroblasts into iNBSCs.
Project description:Reprogramming of somatic cells is a valuable tool to understand the mechanisms of regaining pluripotency and further opens up the possibility of generating patient-specific pluripotent stem cells. Reprogramming of mouse and human somatic cells into pluripotent stem cells, designated as induced pluripotent stem (iPS) cells, has been possible with the expression of the transcription factor quartet Oct4 (also known as Pou5f1), Sox2, c-Myc, and Klf4. Considering that ectopic expression of c-Myc causes tumourigenicity in offspring and retroviruses themselves can cause insertional mutagenesis, the generation of iPS cells with a minimal number of factors may hasten the clinical application of this approach. Here, we show that adult mouse neural stem cells express higher endogenous levels of Sox2 and c-Myc than embryonic stem cells, and that exogenous Oct4 together with either Klf4 or c-Myc are sufficient to generate iPS cells from neural stem cells. These two-factor (2F) iPS cells are similar to embryonic stem cells at the molecular level, contribute to development of the germ line, and form chimeras. We propose that, in inducing pluripotency, the number of reprogramming factors can be reduced when using somatic cells that endogenously express appropriate levels of complementing factors.
Project description:In pluripotential reprogramming, a pluripotent state is established within somatic cells. In this study, we have generated induced pluripotent stem (iPS) cells from bi-maternal (uniparental) parthenogenetic neural stem cells (pNSCs) by transduction with four (Oct4, Klf4, Sox2, and c-Myc) or two (Oct4 and Klf4) transcription factors. The parthenogenetic iPS (piPS) cells directly reprogrammed from pNSCs were able to generate germline-competent himeras, and hierarchical clustering analysis showed that piPS cells were clustered more closer to parthenogenetic ES cells than normal female ES cells. Interestingly, piPS cells showed loss of parthenogenetic-specific imprinting patterns of donor cells. Microarray data also showed that the maternally imprinted genes, which were not expressed in pNSCs, were upregulated in piPS cells, indicating that pluripotential reprogramming lead to induce loss of imprinting as well as re-establishment of various features of pluripotent cells in parthenogenetic somatic cells. 5 samples were analyzed by microarray, each one them in duplicate. fNSC: Mouse female NSC (Neural Stem Cell) pNSC: Mouse parthenogenetic NSC (Neural Stem Cell) piPS-2F: Mouse parthenogenetic induced pluripotent cells derived from NSC overexpressing Oct4 and Klf4 pESC-B: Mouse parthenogenetic ESC (Embryonic Stem Cell) SSEA-1 sorted fESC: Mouse female ESC (Embryonic Stem Cell) OG2
Project description:Chavez2009 - a core regulatory network of OCT4 in human embryonic stem cells
A core OCT4-regulated network has been identified as a test case, to analyase stem cell characteristics and cellular differentiation.
This model is described in the article:
In silico identification of a core regulatory network of OCT4 in human embryonic stem cells using an integrated approach.
Chavez L, Bais AS, Vingron M, Lehrach H, Adjaye J, Herwig R
BMC Genomics, 2009, 10:314
Abstract:
BACKGROUND: The transcription factor OCT4 is highly expressed in pluripotent embryonic stem cells which are derived from the inner cell mass of mammalian blastocysts. Pluripotency and self renewal are controlled by a transcription regulatory network governed by the transcription factors OCT4, SOX2 and NANOG. Recent studies on reprogramming somatic cells to induced pluripotent stem cells highlight OCT4 as a key regulator of pluripotency.
RESULTS: We have carried out an integrated analysis of high-throughput data (ChIP-on-chip and RNAi experiments along with promoter sequence analysis of putative target genes) and identified a core OCT4 regulatory network in human embryonic stem cells consisting of 33 target genes. Enrichment analysis with these target genes revealed that this integrative analysis increases the functional information content by factors of 1.3 - 4.7 compared to the individual studies. In order to identify potential regulatory co-factors of OCT4, we performed a de novo motif analysis. In addition to known validated OCT4 motifs we obtained binding sites similar to motifs recognized by further regulators of pluripotency and development; e.g. the heterodimer of the transcription factors C-MYC and MAX, a prerequisite for C-MYC transcriptional activity that leads to cell growth and proliferation.
CONCLUSION: Our analysis shows how heterogeneous functional information can be integrated in order to reconstruct gene regulatory networks. As a test case we identified a core OCT4-regulated network that is important for the analysis of stem cell characteristics and cellular differentiation. Functional information is largely enriched using different experimental results. The de novo motif discovery identified well-known regulators closely connected to the OCT4 network as well as potential new regulators of pluripotency and differentiation. These results provide the basis for further targeted functional studies.
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Project description:We describe a so far uncharacterized, embryonic and self-renewing Neural Plate Border Stem Cell (NBSC) population with the capacity to differentiate into central nervous and neural crest lineages. NBSCs can be obtained by neural transcription factor-mediated reprogramming (BRN2, SOX2, KLF4, and ZIC3) of human adult dermal fibroblasts and peripheral blood cells (induced Neural Plate Border Stem Cells, iNBSCs) or by directed differentiation from human induced pluripotent stem cells (NBSCs). Moreover, human (i)NBSCs share molecular and functional features with primary Neural Plate Border Stem Cells (pNBSCs) isolated from neural folds of E8.5 mouse embryos. Here we provide single cell RNA-sequencing data of neural tissue derived from two E8.5 mouse embryos. After manual isolation and enzymatic separation E8.5 neural tissue was single cell sorted and RNA sequencing was performed following the Smart-seq2 protocol. In sum, cultured pNBSCs and E8.5 neural tube cells share a similar regional identity and expression signature suggesting that pNBSCs might correspond to an endogenous progenitor in this area of the developing brain.