Since the initial discovery that OCT4, SOX2, KLF4 and c-MYC overexpression sufficed for the induction of pluripotency in somatic cells, methodologies replacing the original factors have enhanced our understanding of the reprogramming process. However, unlike in mouse, OCT4 has not been replaced successfully during reprogramming of human cells. Here we report on a strategy to do so. Through a combination of transcriptome and bioinformatic analysis we have identified factors previously characterized as being lineage specifiers that are able to replace OCT4 and SOX2 in the reprogramming of human fibroblasts. Our results show that is possible to replace OCT4 and SOX2 simultaneously with alternative lineage specifiers in the reprogramming of human cells. At a broader level, they also support a model in which counteracting lineage specification networks underlie the induction of pluripotency,
Reprogramming of human fibroblasts to pluripotency with lineage specifiers.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identification of novel long noncoding RNAs underlying vertebrate cardiovascular development.
Specimen part
View SamplesLong non-coding RNAs (lncRNAs) have emerged as critical regulators of gene expression and chromatin modifications, with important functions in development and disease. Here we sought to identify and functionally characterize lncRNAs critical for vascular vertebrate development with significant conservation across species. Genome-wide transcriptomic analyses during human vascular lineage specification enabled the identification of three conserved novel lncRNAs: TERMINATOR, ALIEN and PUNISHER that are specifically expressed in pluripotent stem cells, mesoderm and endothelial cells, respectively. Gene expression profiling, alongside RNA immunoprecipitation coupled to mass spectrometry, revealed a wide range of new molecular networks and protein interactors related to post-transcriptional modifications for all three lncRNAs. Functional experiments in zebrafish and murine embryos, as well as differentiating human cells, confirmed a developmental-stage specific role for each lncRNA during vertebrate development. The identification and functional characterization of these three novel non-coding provide a comprehensive transcriptomic roadmap and shed new light on the molecular mechanisms underlying human vascular development. Overall design: Time course RNA-Seq analysis H1 ESCs differentiated into endothelial cells
Identification of novel long noncoding RNAs underlying vertebrate cardiovascular development.
No sample metadata fields
View SamplesLong non-coding RNAs (lncRNAs) have emerged as critical regulators of gene expression and chromatin modifications, with important functions in development and disease. Here we sought to identify and functionally characterize lncRNAs critical for vascular vertebrate development with significant conservation across species. Genome-wide transcriptomic analyses during human vascular lineage specification enabled the identification of three conserved novel lncRNAs: TERMINATOR, ALIEN and PUNISHER that are specifically expressed in pluripotent stem cells, mesoderm and endothelial cells, respectively. Gene expression profiling, alongside RNA immunoprecipitation coupled to mass spectrometry, revealed a wide range of new molecular networks and protein interactors related to post-transcriptional modifications for all three lncRNAs. Functional experiments in zebrafish and murine embryos, as well as differentiating human cells, confirmed a developmental-stage specific role for each lncRNA during vertebrate development. The identification and functional characterization of these three novel non-coding provide a comprehensive transcriptomic roadmap and shed new light on the molecular mechanisms underlying human vascular development.
Identification of novel long noncoding RNAs underlying vertebrate cardiovascular development.
No sample metadata fields
View SamplesGene expression from iPSCs before and after gene correction
Targeted gene correction of laminopathy-associated LMNA mutations in patient-specific iPSCs.
Specimen part
View SamplesBackground: Gliomas are the most common type of primary brain tumours, and in this group glioblastomas (GBMs) are the higher-grade gliomas with fast progression and unfortunate prognosis. Two major aspects of glioma biology that contributes to its awful prognosis are the formation of new blood vessels through the process of angiogenesis and the invasion of glioma cells. Despite of advances, two-year survival for GBM patients with optimal therapy is less than 30%. Even in those patients with low-grade gliomas, that imply a moderately good prognosis, treatment is almost never curative. Recent studies have demonstrated the existence of a small fraction of glioma cells with characteristics of neural stem cells which are able to grow in vitro forming neurospheres and that can be isolated in vivo using surface markers such as CD133. The aim of this study was to define the molecular signature of GBM cells expressing CD133 in comparison with non expressing CD133 cells. This molecular classification could lead to the finding of new potential therapeutic targets for the rationale treatment of high grade GBM.
Molecular analysis of ex-vivo CD133+ GBM cells revealed a common invasive and angiogenic profile but different proliferative signatures among high grade gliomas.
Specimen part, Disease
View SamplesWe explored the relationship between Myc activity and PI3K signaling in ESCs. Our data demonstrate that Myc and PI3K signaling function cooperatively for supporting pluripotent property of ESCs. Moreover, our data demonstrate that exposure of ESCs to 2i condition render both Myc and PI3K dispensable for preserving ESC status.
Functional compensation between Myc and PI3K signaling supports self-renewal of embryonic stem cells.
Sex, Specimen part
View SamplesHutchinson-Gilford progeria syndrome (HGPS) is a rare and fatal human premature aging disease1-5, characterized by premature atherosclerosis and degeneration of vascular smooth muscle cells (SMCs)6-8. HGPS is caused by a single-point mutation in the LMNA gene, resulting in the generation of progerin, a truncated mutant of lamin A. Accumulation of progerin leads to various aging-associated nuclear defects including disorganization of nuclear lamina and loss of heterochromatin9-12. Here, we report the generation of induced pluripotent stem cells (iPSCs) from fibroblasts obtained from patients with HGPS. HGPS-iPSCs show absence of progerin, and more importantly, lack the nuclear envelope and epigenetic alterations normally associated with premature aging. Upon differentiation of HGPS-iPSCs, progerin and its associated aging consequences are restored. In particular, directed differentiation of HGPS-iPSCs to SMCs leads to the appearance of premature senescent SMC phenotypes associated with vascular aging. Additionally, our studies identify DNA-dependent protein kinase catalytic subunit (DNAPKcs) as a component of the progerin-containing protein complex. The absence of nuclear DNAPKcs correlates with premature as well as physiological aging. Since progerin also accumulates during physiological aging6,12,13, our results provide an in vitro iPSC-based model with an acceleration progerin accumulation to study the pathogenesis of human premature and physiological vascular aging.
Recapitulation of premature ageing with iPSCs from Hutchinson-Gilford progeria syndrome.
Cell line
View SamplesHeart failure is a leading cause of mortality and morbidity in the developed world, partly because mammals lack the ability to regenerate heart tissue. Whether this is due to evolutionary loss of regenerative mechanisms present in other organisms or to an inability to activate such mechanisms is currently unclear. Here, we decipher mechanisms underlying heart regeneration in adult zebrafish and show that the molecular regulators of this response are conserved in mammals. We identified miR-99/100 and Let-7a/c, and their protein targets smarca5 and fntb, as critical regulators of cardiomyocyte dedifferentiation and heart regeneration in zebrafish. Although human and murine adult cardiomyocytes fail to elicit an endogenous regenerative response following myocardial infarction, we show that in vivo manipulation of this molecular machinery in mice results in cardiomyocyte dedifferentiation and improved heart functionality after injury. These data provide a proof-of-concept for identifying and activating conserved molecular programs to regenerate the damaged heart. Overall design: RNA-Seq expression profiles of rat cardiomyocytes after knockdown of miR-99/100 and Let-7 miRNAs
In vivo activation of a conserved microRNA program induces mammalian heart regeneration.
No sample metadata fields
View SamplesGenetic mutations on leucine-rich repeat kinase 2 (LRRK2) have been associated with an increased risk of Parkinson's disease. The Gly2019Ser (G2019S) mutation on LRRK2 gene is a relatively common cause of familial Parkinson's disease in Caucasian population. In this study, we generated human induced pluripotent stem cell (iPSC) lines from LRRK2 (G2019S) bearing patient fibroblasts by cell reprogramming.
Progressive degeneration of human neural stem cells caused by pathogenic LRRK2.
No sample metadata fields
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