Methods of reprogramming somatic cells to an induced pluripotent state (iPSC) have enabled the direct modeling of human disease and ultimately promise to revolutionize regenerative medicine. iPSCs offer an invaluable source of patient-specific pluripotent stem cells for disease modeling, drug screening, toxicology tests and importantly for regenerative medicine, and already have been employed to unmask novel insights into human diseases. While iPSCs can be consistently generated through overexpression of the four Yamanaka Factors OCT4, SOX2, KLF4 and c-MYC (OSKM), reprogrammed cells present worrisome differences with embryonic stem cells in transcriptional and epigenetic profiles, as well as developmental potential and difficulties in cell culturing. A thorough mechanistic understanding of the reprogramming process is critical to overcoming these barriers to the clinical use of iPSC. We have recently published a novel factor combination based on molecules specifically enriched in the metaphase II human oocyte. We have shown that just the overexpression of histone-remodeling chaperone ASF1A and OCT4 in hADFs previously exposed to the oocyte-specific paracrine growth factor GDF9 can reprogram hADFs into pluripotent cells (AO9-iPSCs). Our study contributes to the understanding of the molecular pathways governing somatic cell reprogramming. Here we want to go deeper in the reprogramming mechanisms by understanding the importance of somatic cell origin, and analyzing (and establishing comparison with) the transcriptional and epigenetic characteristics of AO9-iPSCs. As the intrinsic histone chaperone activity of ASF1A and our data indicate, these cells could be closer to the embryonic pluripotent state, with less epigenetic memory, better culture properties and differentiation potential.
Analysis of Menstrual Blood Stromal Cells Reveals SOX15 Triggers Oocyte-Based Human Cell Reprogramming.
Sex, Specimen part, Subject
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The Scc2-Scc4 complex acts in sister chromatid cohesion and transcriptional regulation by maintaining nucleosome-free regions.
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View SamplesSadanandam et al. (2013) recently published a study based on the use of microarray data to classify colorectal cancer (CRC) samples. The classification claimed to have strong clinical implications, as reflected in the paper title: A colorectal cancer classification system that associates cellular phenotype and responses to therapy. They defined five subtypes: (i) inflammatory; (ii) goblet-like; (iii) enterocyte; (iv) transit-amplifying; and (v) stem-like. Based on drug sensitivity data from 21 patients, they also reported that the so-called stem-like subtype show differential sensitivity to FOLFIRI. This is the key result in their publication, since it implies a direct relation between the subtype and the choice of CRC therapy (i.e. FOLFIRI response). However, our analyses using the same drug sensitivity data and results from additional patients showed that the CRC classification reported by Sadanandam et al. is not predictive of FOLFIRI response.
Colorectal cancer classification based on gene expression is not associated with FOLFIRI response.
Specimen part
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Budding yeast Wapl controls sister chromatid cohesion maintenance and chromosome condensation.
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View SamplesThe Scc2/Scc4 complex binds to broad nucleosome-free regions in the promoters of highly expressed genes. The cohesin loader is recruited to these sites by the RSC chromatin remodeling complex
The Scc2-Scc4 complex acts in sister chromatid cohesion and transcriptional regulation by maintaining nucleosome-free regions.
No sample metadata fields
View SamplesCohesin acetylation by Eco1 during DNA replication establishes sister chromatid cohesion. We show that acetylation makes cohesin resistant to Wapl activity from S-phase until mitosis. Wapl turns out to be a key regulator of cohesin dynamics on chromosomes by controling cohesin maintenance following its establishment in S-phase and its role in chromosome condensation.
Budding yeast Wapl controls sister chromatid cohesion maintenance and chromosome condensation.
No sample metadata fields
View SamplesGranulomas are immune cell aggregates formed in response to persistent inflammatory stimuli. Granuloma macrophage subsets are diverse and carry varying copy numbers of their genomic information. The molecular programs that control the differentiation of such macrophage populations in response to a chronic stimulus, though critical for disease outcome, have not been defined. In this study, we performed scRNA-Seq experiments to gain insights into the transcriptional regulation of polyploid macrophage differentiation in response to chronically persistent inflammatory stimuli. Overall design: scRNA-Seq was performed on FACS-sorted 2c and >4c DNA content polyploid macrophages after six days of bacterial lipoprotein, FSL-1 treatment of bone marrow-derived macrophage precursors. 2c DNA content macrophages treated with M-CSF alone were used as controls. CEL-Seq2 protocol was used for single cell sequencing (Hashimshony et al. 2016).
DNA Damage Signaling Instructs Polyploid Macrophage Fate in Granulomas.
Specimen part, Cell line, Subject
View SamplesHistone acetylation and other modifications of the chromatin are important regulators of gene expression and, consequently, may contribute to drug-induced behaviors and neuroplasticity. Previous studies have shown that a reduction on histone deacetylase (HDAC) activity results on the enhancement of some psychostimulant-induced behaviors. In the present study, we extend those seminal findings by showing that the administration of the HDAC inhibitor sodium butyrate enhances morphine-induced locomotor sensitization and conditioned place preference. In contrast, this compound has no effects on the development of morphine tolerance and dependence. Similar effects were observed for cocaine and ethanol-induced behaviors. These behavioral changes were accompanied by a selective boosting of a component of the transcriptional program activated by chronic morphine administration that included circadian clock genes and other genes relevant in addictive behavior. Our results support an specific role for histone acetylation and the epigenetic modulation of transcription at a reduced number of biologically relevant loci on non-homeostatic, long lasting, drug-induced behavioral plasticity. To further investigate the molecular bases of sodium butyrate action on long-lasting behavioral responses to morphine, we screened for potential substrates of their interaction by performing a genome-wide comparison of the striatal transcriptome after chronic administration of morphine in the absence or presence of sodium butyrate.
Selective boosting of transcriptional and behavioral responses to drugs of abuse by histone deacetylase inhibition.
Sex, Age, Specimen part
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Genomic landscape of transcriptional and epigenetic dysregulation in early onset polyglutamine disease.
Sex, Age, Specimen part
View SamplesTranscriptional dysregulation is an important early feature of polyglutamine diseases. One of its proposed causes is defective neuronal histone acetylation, but important aspects of this hypothesis, such as the precise genomic topography of acetylation deficits
Genomic landscape of transcriptional and epigenetic dysregulation in early onset polyglutamine disease.
Sex, Age, Specimen part
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