Project description:Genetic control of pluripotent mammalian ES cells is determined by a transcriptional network, with a "central core" of transcription factors, Pou5f1, Sox2 and Nanog. Zebrafish homologues of the "core pluripotency factors" Pou5f1, SoxB1 and Nanog-like are also crucially involved in early development. However, the degree of functional similarity of the network between mammals and non-mammals is a matter of debate. To identify the components of Pou5f1-dependent transcriptional networks, we determined the genomic binding sites for Pou5f1 and Sox2 in late blastula stage zebrafish embryos using ChIP-seq. We found that Sox2 and Pou5f1 are co-binding to the regulatory regions of Sox2, Pou5f1, and Nanog-like, as well as to multiple orthologues of mammalian plutipotency network components.
Project description:Genetic control of pluripotent mammalian ES cells is determined by a transcriptional network, with a "central core" of transcription factors, Pou5f1, Sox2 and Nanog. Zebrafish homologues of the "core pluripotency factors" Pou5f1, SoxB1 and Nanog-like are also crucially involved in early development. However, the degree of functional similarity of the network between mammals and non-mammals is a matter of debate. To identify the components of Pou5f1-dependent transcriptional networks, we determined the genomic binding sites for Pou5f1 and Sox2 in late blastula stage zebrafish embryos using ChIP-seq. We found that Sox2 and Pou5f1 are co-binding to the regulatory regions of Sox2, Pou5f1, and Nanog-like, as well as to multiple orthologues of mammalian plutipotency network components. Deep sequencing was performed using the Illumina GAIIx on DNA samples obtained from Sox2 ChIP, Pou5f1-Flag ChIP and Input Control. Pou5f1 was analysed in technical duplicates to obtain higher sequencing depth.
Project description:Chickarmane2006 - Stem cell switch irreversible
Kinetic modeling approach of the transcriptional dynamics of the embryonic stem cell switch.
This model is described in the article:
Transcriptional dynamics of the embryonic stem cell switch.
Chickarmane V, Troein C, Nuber UA, Sauro HM, Peterson C
PLoS Computational Biology. 2006; 2(9):e123
Abstract:
Recent ChIP experiments of human and mouse embryonic stem cells have elucidated the architecture of the transcriptional regulatory circuitry responsible for cell determination, which involves the transcription factors OCT4, SOX2, and NANOG. In addition to regulating each other through feedback loops, these genes also regulate downstream target genes involved in the maintenance and differentiation of embryonic stem cells. A search for the OCT4-SOX2-NANOG network motif in other species reveals that it is unique to mammals. With a kinetic modeling approach, we ascribe function to the observed OCT4-SOX2-NANOG network by making plausible assumptions about the interactions between the transcription factors at the gene promoter binding sites and RNA polymerase (RNAP), at each of the three genes as well as at the target genes. We identify a bistable switch in the network, which arises due to several positive feedback loops, and is switched on/off by input environmental signals. The switch stabilizes the expression levels of the three genes, and through their regulatory roles on the downstream target genes, leads to a binary decision: when OCT4, SOX2, and NANOG are expressed and the switch is on, the self-renewal genes are on and the differentiation genes are off. The opposite holds when the switch is off. The model is extremely robust to parameter changes. In addition to providing a self-consistent picture of the transcriptional circuit, the model generates several predictions. Increasing the binding strength of NANOG to OCT4 and SOX2, or increasing its basal transcriptional rate, leads to an irreversible bistable switch: the switch remains on even when the activating signal is removed. Hence, the stem cell can be manipulated to be self-renewing without the requirement of input signals. We also suggest tests that could discriminate between a variety of feedforward regulation architectures of the target genes by OCT4, SOX2, and NANOG.
This model is hosted on BioModels Database
and identified by: MODEL7957942740
.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models
.
To the extent possible under law, all copyright and related or neighbouring rights to this encoded model have been dedicated to the public domain worldwide. Please refer to CC0 Public Domain Dedication
for more information.
Project description:Chickarmane2006 - Stem cell switch reversible
Kinetic modeling approach of the transcriptional dynamics of the embryonic stem cell switch.
This model is described in the article:
Transcriptional dynamics of the embryonic stem cell switch.
Chickarmane V, Troein C, Nuber UA, Sauro HM, Peterson C
PLoS Computational Biology. 2006; 2(9):e123
Abstract:
Recent ChIP experiments of human and mouse embryonic stem cells have elucidated the architecture of the transcriptional regulatory circuitry responsible for cell determination, which involves the transcription factors OCT4, SOX2, and NANOG. In addition to regulating each other through feedback loops, these genes also regulate downstream target genes involved in the maintenance and differentiation of embryonic stem cells. A search for the OCT4-SOX2-NANOG network motif in other species reveals that it is unique to mammals. With a kinetic modeling approach, we ascribe function to the observed OCT4-SOX2-NANOG network by making plausible assumptions about the interactions between the transcription factors at the gene promoter binding sites and RNA polymerase (RNAP), at each of the three genes as well as at the target genes. We identify a bistable switch in the network, which arises due to several positive feedback loops, and is switched on/off by input environmental signals. The switch stabilizes the expression levels of the three genes, and through their regulatory roles on the downstream target genes, leads to a binary decision: when OCT4, SOX2, and NANOG are expressed and the switch is on, the self-renewal genes are on and the differentiation genes are off. The opposite holds when the switch is off. The model is extremely robust to parameter changes. In addition to providing a self-consistent picture of the transcriptional circuit, the model generates several predictions. Increasing the binding strength of NANOG to OCT4 and SOX2, or increasing its basal transcriptional rate, leads to an irreversible bistable switch: the switch remains on even when the activating signal is removed. Hence, the stem cell can be manipulated to be self-renewing without the requirement of input signals. We also suggest tests that could discriminate between a variety of feedforward regulation architectures of the target genes by OCT4, SOX2, and NANOG.
This model is hosted on BioModels Database
and identified by: MODEL7957907314
.
To cite BioModels Database, please use: BioModels Database: An enhanced, curated and annotated resource for published quantitative kinetic models
.
To the extent possible under law, all copyright and related or neighbouring rights to this encoded model have been dedicated to the public domain worldwide. Please refer to CC0 Public Domain Dedication
for more information.
Project description:CD90+ prostate cancer-associated (CP) stromal cells represent a disease cell type found only in tumor tissue. Genetic reprogramming by induced pluripotent stem (iPS) cell technology might be used to “normal gene expression of diseased cells thereby providing a cure. The resultant iPS cells would no longer express the disease program, and, like stem cells, might respond to normal differentiative signaling. Thus, CP stromal cells, isolated from tumor tissue and cultured in vitro, were transfected with POU5F1/LIN28/NANOG/SOX2 lentiviral vectors. iPS cells were obtained at a frequency of 10^4. Transcriptome analysis showed an almost complete match in gene expression between the iPS cells and human embryonic stem cells. Genes of CP stromal cells were fully inactivated. CP stromal cells were isolated from tissue, cultured and transfected with lentiviral vectors containing NANOG, SOX2, POU5F1, LIN28. The resultant induced pluripotent cells were analyzed by DNA microarrays.
Project description:To decipher gene regulatory networks, we used systematic suppression of 97 transcription factors (TFs) and 7 other genes with shRNA in mouse embryonic stem (ES) cells, followed by global gene expression profiling. Meta-analysis of these data together with the earlier data obtained by the induction of 50 TFs and the existing genome-wide data on TF binding sites identified the sets of regulated target genes for 23 TFs. Principal component analysis shows different roles of two groups of TFs that are active in ES cells: Pou5f1 and Sox2 support the expression of their target genes and prevent the upregulation of trophectoderm-related genes, whereas Esrrb, Sall4, Nanog, Gbx2, Grhl2, Mtf2, Aff1, Tcfap4, and Cdc5l support the expression of targets of Esrrb, including glycolysis genes, and prevent upregulation of targets of Trp53 and Polycomb TFs. If TFs from the second group are downregulated while Pou5f1 and Sox2 are still active, then the cell state changes towards epiblast lineages.
Project description:The transcription factors Oct4, Sox2, and Nanog have essential roles in early development and are required for the propagation of undifferentiated embryonic stem (ES) cells in culture. To gain insights into transcriptional regulation of human ES cells, we have identified Oct4, Sox2, and Nanog target genes using genome-scale location analysis. We found, surprisingly, that Oct4, Sox2, and Nanog co-occupy a substantial portion of their target genes. These target genes frequently encode transcription factors, many of which are developmentally important homeodomain proteins. Our data also indicates that Oct4, Sox2, and Nanog collaborate to form regulatory circuitry in ES cells consisting of autoregulatory and feedforward loops. These results provide new insights into the transcriptional regulation of stem cells and reveal how Oct4, Sox2, and Nanog contribute to pluripotency and self-renewal.
Project description:Pou5f1 and Sox2 overexpression experiments with protein synthesis inhibitor were performed to investigate direct transcriptional targets of Pou5f1 and Sox2
Project description:Pou5f1 and Sox2 overexpression experiments with and without protein synthesis inhibitor were performed to investigate direct transcriptional targets of Pou5f1 and Sox2
Project description:This series of experiments will serve as quality control for NIH registered human embryonic stem (hES) cell lines. For example, hES cell marker genes, such as POU5F1, SOX2 and NANOG, should have high expression levels, while differentiation markers, such as NEUROD1 and PAX6, should have low expression levels. The difference between different stem cell lines should be revealed by the difference between expression levels of different markers. Keywords: Expression Chip