We investigated the global gene expression changes in normal and Brg1-deleted mesoderm differentiation of mouse embryonic stem cells. Overall design: RNAseq analysis of poly-adenylated RNA levels for 3 conditions: Day2 of differentiation, Day4 THF (Control), and Day4 4OHT (Brg1-deleted). 2 replicates per condition.
Brg1 modulates enhancer activation in mesoderm lineage commitment.
Cell line, Subject, Time
View SamplesThe reprogramming of fibroblast cells to induced pluripotent stem (iPS) cells raises the possibility that a somatic cell could be reprogrammed to an alternative differentiated fate without first becoming a stem/progenitor cell. A large pool of fibroblast cells exists in the post-natal heart, yet no single master regulator of direct cardiac reprogramming has been identified. Here, we report that a combination of three developmental transcription factors (i.e., Gata4, Mef2c and Tbx5) rapidly and efficiently reprogrammed post-natal cardiac or tail-tip fibroblasts directly into differentiated cardiomyocyte-like cells. Induced cardiomyocytes expressed cardiac-specific markers, had a global gene expression profile similar to cardiomyocytes, and contracted spontaneously. Fibroblast cells transplanted into mouse hearts one day after transduction of the three factors also differentiated into cardiomyocyte-like cells. These findings demonstrate that functional cardiomyocytes can be directly reprogrammed from differentiated somatic cells by defined factors. Reprogramming of endogenous or explanted fibroblast cells might provide a source of cardiomyocytes for regenerative approaches.
Direct reprogramming of fibroblasts into functional cardiomyocytes by defined factors.
Specimen part
View SamplesRPB1, the largest subunit of RNA polymerase II, contains a highly modifiable C-terminal domain (CTD) that consists of variations of a consensus heptad repeat sequence (Y1S2P3T4S5P6S7). The consensus CTD repeat motif and tandem organization represent the ancestral state of eukaryotic RPB1, but across eukaryotes CTDs show considerable diversity in repeat organization and sequence content. These differences may reflect lineage-specific CTD functions mediated by protein interactions. Mammalian CTDs contain eight non-consensus repeats with a lysine in the seventh position (K7). Posttranslational acetylation of these sites was recently shown to be required for proper polymerase pausing and regulation of two growth factor-regulated genes. To investigate the origins and function of RPB1 CTD acetylation (acRPB1), we computationally reconstructed the evolution of the CTD repeat sequence across eukaryotes and analyzed the evolution and function of genes dysregulated when acRPB1 is disrupted. Modeling the evolutionary dynamics of CTD repeat count and sequence content across diverse eukaryotes revealed an expansion of the CTD in the ancestors of Metazoa. The new CTD repeats introduced the potential for acRPB1 due to the appearance of distal repeats with lysine at position seven. This was followed by a further increase in the number of lysine-containing repeats in developmentally complex clades like Deuterostomia. Mouse genes enriched for acRPB1 occupancy at their promoters and genes with significant expression changes when acRPB1 is disrupted are enriched for several functions, such as growth factor response, gene regulation, cellular adhesion, and vascular development. Genes occupied and regulated by acRPB1 show significant enrichment for evolutionary origins in the early history of eukaryotes through early vertebrates. Our combined functional and evolutionary analyses show that RPB1 CTD acetylation was possible in the early history of animals, and that the K7 content of the CTD expanded in specific developmentally complex metazoan lineages. The functional analysis of genes regulated by acRPB1 highlight functions involved in the origin of and diversification of complex Metazoa. This suggests that acRPB1 may have played a role in the success of animals.
Evolution of lysine acetylation in the RNA polymerase II C-terminal domain.
Cell line
View SamplesAnalysis of the roles of Irx3 and Irx5 transcription factors in mouse heart development and postnatal heart function. Results show that show that Irx3 and Irx5 have redundant function in the in the endocardium to regulate atrioventricular canal morphogenesis and outflow tract formation. A postnatal deletion of Irx3 and Irx5 surprisingly results in a restoration of the repolarization gradient that is altered in Irx5 mutant hearts, suggesting a model whereby postnatal Irx3 activity is normally repressed by Irx5.
Cooperative and antagonistic roles for Irx3 and Irx5 in cardiac morphogenesis and postnatal physiology.
Specimen part
View SamplesAdult-onset diseases can be associated with in utero events, but mechanisms for such temporally distant dysregulation of organ function remain unknown. The polycomb histone methyltransferase, Ezh2, stabilizes transcription by depositing repressive histone marks during development that persist into adulthood, but the function of Ezh2-mediated transcriptional stability in postnatal organ homeostasis is not understood. Here, we show that Ezh2 stabilizes the postnatal cardiac gene expression program and prevents cardiac pathology, primarily by repressing the homeodomain transcription factor Six1 in differentiating cardiac progenitors. Loss of Ezh2 in embryonic cardiac progenitors, but not in differentiated cardiomyocytes, resulted in postnatal cardiac pathology, including cardiomyocyte hypertrophy and fibrosis. Loss of Ezh2 caused broad derepression of skeletal muscle genes, including the homeodomain transcription factor Six1, which is expressed in cardiac progenitors but is normally silenced upon cardiac differentiation. Many of the deregulated genes are direct Six1 targets, implying a critical requirement for stable repression of Six1 in cardiac myocytes. Indeed, upon de-repression, Six1 promotes cardiac pathology, as it was sufficient to induce cardiac hypertrophy. Furthermore, genetic reduction of Six1 levels almost completely rescued the pathology of Ezh2-deficient hearts. Thus, repression of a single transcription factor in cardiac progenitors by Ezh2 is essential for stability of the adult heart gene expression program and homeostasis. Our results suggest that epigenetic dysregulation during discrete developmental windows can predispose to adult disease and dysregulated stress responses.
Epigenetic repression of cardiac progenitor gene expression by Ezh2 is required for postnatal cardiac homeostasis.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
miR-126 regulates angiogenic signaling and vascular integrity.
No sample metadata fields
View SamplesFish, JE, Santoro, MM, Morton, SU, Yu, S, Yeh, RF, Wythe, JD, Ivey, KI, Bruneau, BG, Stainier, DYR, and Srivastava, D. (2008). miR-126 Regulates Angiogenic Signaling and Vascular Integrity. Developmental Cell 15, 272-284.
miR-126 regulates angiogenic signaling and vascular integrity.
No sample metadata fields
View SamplesFish, JE, Santoro, MM, Morton, SU, Yu, S, Yeh, RF, Wythe, JD, Ivey, KI, Bruneau, BG, Stainier, DYR, and Srivastava, D. (2008). miR-126 Regulates Angiogenic Signaling and Vascular Integrity. Developmental Cell 15, 272-284.
miR-126 regulates angiogenic signaling and vascular integrity.
No sample metadata fields
View SamplesImatinib has become the current standard therapy for patients with chronic myelogenous leukaemia (CML). For a better understanding of the Imatinib-related molecular effects in vivo, we assessed gene expression profiles of Philadelphia Chromosome positive (Ph+) CD34+ cells from peripheral blood of 6 patients with de novo CML in chronic phase. After 7 days of treatment with Imatinib the Ph+ CD34+ cells were reassessed to look for changes in the transcriptome. The expression level of 303 genes was significantly different comparing the transcriptome of the Ph+ CD34+ cells before and after 7 days of Imatinib therapy (183 down-regulated, 120 up-regulated, lower bound 1.2-fold). For a substantial number of genes governing cell cycle and DNA replication, the level of expression significantly decreased (CDC2, RRM2, PCNA, MCM4). On the other hand, therapy with Imatinib was associated with an increase of genes related to adhesive interactions, such as L-selectin or CD44. A group of 8 genes with differential expression levels were confirmed using a gene specific quantitative real-time PCR. Thus, during the first week of treatment, Imatinib is preferentially counteracting the bcr-abl induced effects related to a disturbed cell cycle and defective adhesion of leukemic Ph+ CD34+ cells.
Early in vivo changes of the transcriptome in Philadelphia chromosome-positive CD34+ cells from patients with chronic myelogenous leukaemia following imatinib therapy.
No sample metadata fields
View SamplesThe objective of this study is to create an encyclopedia of all genes expressed in the glomerular endothelial cell under normal and diabetic conditions. We utilized Tie2-GFP transgenic mice to mark cells of the glomerular endothelium. To induce diabetic nephropathy (DB), a genetic model of DB, BKS.Cg-m +/+ Leprdb/J from Jax laboratories was used. We utilized fluorescent activated cell sorting (FACS) to isolate glomerular endothelial cells from normal and diabetic mice. The RNAs from these samples were isolated and utilized to hybridize to microarrays, which offers a powerful, efficient and effective method for the creation of a gene expression atlas.
Gene expression programs of mouse endothelial cells in kidney development and disease.
Age, Specimen part
View Samples