Project description:MyoD is known to transdifferentiate fibroblasts into muscle-like cells. Despite phenotypic resemblance and expression of myogenic marker genes in transdifferentiated cells, our global gene expression data suggests that ~100 genes, many involved in muscle development and function, remain non-reprogrammed. To understand this incomplete reprogramming, we characterized genome-wide chromatin accessibility and MyoD binding in human primary myoblasts and in MyoD-induced skin fibroblast cells. Our analyses revealed thousands of sites with incomplete chromatin reprogramming.Combined analyses of gene expression and epigenetic profiles revealed that many myogenic genes not upregulated during the transdifferentiation process have undergone MyoD-dependent chromatin remodeling, but to a significantly lower extent than reprogrammed genes. Our findings suggest that incomplete MyoD-induced transdifferentiation is due to chromatin-remodeling deficiencies, and that additional factors are required to transdifferentiate cells into a state more similar to myoblasts.
Project description:MyoD is known to transdifferentiate fibroblasts into muscle-like cells. Despite phenotypic resemblance and expression of myogenic marker genes in transdifferentiated cells, our global gene expression data suggests that ~100 genes, many involved in muscle development and function, remain non-reprogrammed. To understand this incomplete reprogramming, we characterized genome-wide chromatin accessibility and MyoD binding in human primary myoblasts and in MyoD-induced skin fibroblast cells. Our analyses revealed thousands of sites with incomplete chromatin reprogramming.Combined analyses of gene expression and epigenetic profiles revealed that many myogenic genes not upregulated during the transdifferentiation process have undergone MyoD-dependent chromatin remodeling, but to a significantly lower extent than reprogrammed genes. Our findings suggest that incomplete MyoD-induced transdifferentiation is due to chromatin-remodeling deficiencies, and that additional factors are required to transdifferentiate cells into a state more similar to myoblasts.
Project description:MyoD is known to transdifferentiate fibroblasts into muscle-like cells. Despite phenotypic resemblance and expression of myogenic marker genes in transdifferentiated cells, our global gene expression data suggests that ~100 genes, many involved in muscle development and function, remain non-reprogrammed. To understand this incomplete reprogramming, we characterized genome-wide chromatin accessibility and MyoD binding in human primary myoblasts and in MyoD-induced skin fibroblast cells. Our analyses revealed thousands of sites with incomplete chromatin reprogramming.Combined analyses of gene expression and epigenetic profiles revealed that many myogenic genes not upregulated during the transdifferentiation process have undergone MyoD-dependent chromatin remodeling, but to a significantly lower extent than reprogrammed genes. Our findings suggest that incomplete MyoD-induced transdifferentiation is due to chromatin-remodeling deficiencies, and that additional factors are required to transdifferentiate cells into a state more similar to myoblasts.
Project description:To understand the effect of LncMyod on MyoD-induced transdifferentiation of 10T1/2 fibroblast cells, we performed RNA-seq on LncMyoD-KO 10T1/2 fibroblasts with MyoD-induced transdifferentiation.
Project description:The regulatory networks of differentiation programs have been partly characterized; however, the molecular mechanisms of lineage-specific gene regulation by highly similar transcription factors remain largely unknown. Here we compare the genome-wide binding and transcription profiles of NEUROD2-mediated neurogenesis with MYOD-mediated myogenesis. We demonstrate that NEUROD2 and MYOD bind a shared CAGCTG E-box motif and E-box motifs specific for each factor: CAGGTG for MYOD and CAGATG for NEUROD2. Binding at factor-specific motifs is associated with gene transcription, whereas binding at shared sites is associated with regional epigenetic modifications but not as strongly associated with gene transcription. Binding is largely constrained to E-boxes pre-set in an accessible chromatin context that determines the set of target genes activated in each cell type. These findings demonstrate that the differentiation program is genetically determined by E-box sequence whereas cell lineage epigenetically determines the availability of E-boxes for each differentiation program. Comparing NeuroD2 induced neurogenesis and MyoD induced myogenesis by examining NeuroD2/MyoD binding sites in fibroblasts and P19 cells and corresponding changes in AcH4 using Chip-Seq. Assess chromatin accessibility using PvuII assay followed by high throughput sequencing.
Project description:Collombet2016 - Lymphoid and myeloid cell
specification and transdifferentiation
This model is described in the article:
Logical modeling of lymphoid
and myeloid cell specification and transdifferentiation
Samuel Collombet, Chris van Oevelen,
Jose Luis Sardina Ortega, Wassim Abou-Jaoudé, Bruno Di
Stefano, Morgane Thomas-Chollier, Thomas Graf, and Denis
Thieffry
Proceedings of the National Academy of
Sciences of the United States of America
Abstract:
Blood cells are derived from a common set of hematopoietic
stem cells, which differentiate into more specific progenitors
of the myeloid and lymphoid lineages, ultimately leading to
differentiated cells. This developmental process is controlled
by a complex regulatory network involving cytokines and their
receptors, transcription factors, and chromatin remodelers.
Using public data and data from our own molecular genetic
experiments (quantitative PCR, Western blot, EMSA) or
genome-wide assays (RNA-sequencing, ChIP-sequencing), we have
assembled a comprehensive regulatory network encompassing the
main transcription factors and signaling components involved in
myeloid and lymphoid development. Focusing on B-cell and
macrophage development, we defined a qualitative dynamical
model recapitulating cytokine-induced differentiation of common
progenitors, the effect of various reported gene knockdowns,
and the reprogramming of pre-B cells into macrophages induced
by the ectopic expression of specific transcription factors.
The resulting network model can be used as a template for the
integration of new hematopoietic differentiation and
transdifferentiation data to foster our understanding of
lymphoid/myeloid cell-fate decisions.
This model is hosted on
BioModels Database
and identified by:
MODEL1610240000.
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:The eukaryotic genome is organized into chromatins, the physiological template for DNA-dependent processes including replication, recombination, repair, and transcription. Chromatin-mediated transcription regulation involves DNA methylation, chromatin remodeling, and histone modifications. However, chromatin also contains non-histone chromatin-associated proteins, of which the high-mobility group (HMG) proteins are the most abundant. Although it is known that HMG proteins induce structural changes of chromatin, the processes underlying transcription regulation by HMG proteins are poorly understood. Here we decipher the molecular mechanism of transcription regulation mediated by the HMG AT-hook 2 protein (HMGA2). We combined proteomic, ChIP-seq, and transcriptome data to show that HMGA2-induced transcription requires phosphorylation of the histone variant H2AX at S139 (H2AXS139ph; γ-H2AX) mediated by the protein kinase ataxia telangiectasia mutated (ATM). Furthermore, we demonstrate the biological relevance of this mechanism within the context of TGFβ1 signaling. The interplay between HMGA2, ATM, and H2AX is a novel mechanism of transcription initiation. Our results link H2AXS139ph to transcription, assigning a new function for this DNA damage marker. Controlled chromatin opening during transcription may involve intermediates with DNA breaks that may require mechanisms that ensure the integrity of the genome.