Outbred D.melanogaster populations subjected to >300 generations of natural selection on either control, or 12% ethanol, or variable food (2 replicates each) and exposed, as first instar larvae, to either water control or 12% ethanol.
Evolution of gene expression and expression plasticity in long-term experimental populations of Drosophila melanogaster maintained under constant and variable ethanol stress.
No sample metadata fields
View SamplesFK1706 potentiated nerve growth factor-induced neurite outgrowth, putatively mediated via FKBP-52 and the Ras/Raf/MAPK signaling pathway. It also improved mechanical allodynia accompanied by the recovery of intraepidermal nerve fiber density in a painful diabetic neuropathy in rats.
FK1706, a novel non-immunosuppressive immunophilin ligand, modifies gene expression in the dorsal root ganglia during painful diabetic neuropathy.
Specimen part, Treatment
View SamplesOct3/4, Sox2, Klf4, and c-Myc re-wire somatic cells to achieve induced pluripotency (iPS cells). However, subtle differences in reprogramming methodology may confound comparative studies of reprogramming-induced gene expression changes. We specifically focused on the design of polycistronic reprogramming constructs, which encode all four factors linked with 2A peptides. Notably, publically available cassettes were found to employ one of two Klf4 variants (Klf4S and Klf4L; GenBank Accession Nos: AAC52939.1 and AAC04892.1), differing only by nine N-terminal amino acids. In a polycistronic context, these two variants generated dissimilar protein stoichiometry, where Klf4L vectors produced more Klf4 protein than those encoding Klf4S.
KLF4 N-terminal variance modulates induced reprogramming to pluripotency.
Sex, Specimen part
View SamplesWe report that Zic family (Zic1/2/3) and orphan nuclear receptors family (Esrrb and Nr5a2) transcription factors (TFs) synergistically enhance the reprogramming efficiency when transduced with Oct4, Sox2 and Klf4 (OSK) into murine fibroblasts. To identify the molecular mechanisms underlying this synergy, we analyzed global gene expression at 6 days after introduction of reprogramming factors. As a result, we found that primary targets of these TFs are different when either of TFs was introduced with OSK, but a significant portion of genes including pluripotency makers such as Dppa2 was synergistically upregulated. Further analysis revealed that metabolic pathways are the important targets of these TFs for efficient reprogramming.
Hybrid Cellular Metabolism Coordinated by Zic3 and Esrrb Synergistically Enhances Induction of Naive Pluripotency.
No sample metadata fields
View SamplesThe spectrum of genetic mutations differs among cancers in different organs, implying a cellular context-dependent effect of the genetic aberrations. However, the extent to which the cellular context affects the consequences of oncogenic mutations remains to be fully elucidated. We reprogrammed colon tumor cells in an Apc Min/+ mouse model, in which the loss of the Apc gene plays a critical role in tumor development, and established reprogrammed tumor cells (RTCs) that exhibit pluripotent stem cell (PSC)-like signatures of gene expression. We show that the majority of the genes in the RTCs that were affected by the Apc mutations did not overlap with the genes that were affected in the intestine or those that were affected by the accumulation of beta-catenin in PSCs. The RTCs lacked pluripotency but exhibited the increased expression of Cdx2 and a differentiation propensity that was biased toward the trophectoderm cell lineage. The genetic rescue of the mutated Apc allele conferred pluripotency on the RTCs and enabled their differentiation into various cell types in vivo. The re-disruption of Apc in the RTC-derived differentiated cells resulted in neoplastic growth that was exclusive to the intestine, yet the majority of intestinal lesions remained pre-tumoral microadenomas. These results highlight the significant influence of the cellular context on gene regulation, cellular plasticity, and cellular behavior in response to the loss of the Apc function. Our results also imply that transition from microadenomas to macroscopic tumors is reprogrammable, which underscores the importance of epigenetic regulation on colon tumor promotion.
Cellular context-dependent consequences of Apc mutations on gene regulation and cellular behavior.
Specimen part
View SamplesSplicing profiles in pluripotent stem cells are different from those in somatic cells. Generally, alternative splicing is regulated by RNA binding proteins. To identify the candidate RNA-binding protein-encoding genes, we performed gene expression profiling experiments.
Global splicing pattern reversion during somatic cell reprogramming.
Specimen part, Cell line
View SamplesTo identify the genes whose expression levels are changed before and after somatic cell reprogramming, we performed global gene expression analysis of iPS cells and their original fibrobrasts.
Structural and spatial chromatin features at developmental gene loci in human pluripotent stem cells.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Srf destabilizes cellular identity by suppressing cell-type-specific gene expression programs.
Specimen part
View SamplesThere is a gradient of -catenin expression along the colonic crypt axis with the highest levels at the crypt bottom. However, it remains unclear whether different levels of canonical Wnt signaling exert distinct roles in the colonic epithelium. In the present study, we first showed that the canonical Wnt signaling is active in the proliferative compartment of normal colonic crypts by separating actively proliferating progenitor cells from non-proliferating cells in the colon using transgenic mice expressing a histone H2B-green fluorescent protein (GFP) fusion protein under the control of a tetracycline responsive regulatory element. Subsequently, we investigated the dose-dependent effect of canonical Wnt activation on colonic epithelial differentiation by controlling the expression levels of stabilized -catenin using a doxycycline-inducible transgenic system in mice. We show that elevated levels of Wnt signaling induce the amplification of Lgr5+ cells, which is accompanied by crypt fission and a reduction in cell proliferation among progenitor cells. In contrast, lower levels of -catenin induction enhanced cell proliferation rates of epithelial progenitors without affecting crypt fission rates. Notably, slow-cycling cells produced by -catenin activation exhibit activation of Notch signaling and the treatment of -catenin expressing mice with a Notch inhibitor turned such slow-cycling cells into actively proliferating cells. Our results indicate that the activation of the canonical Wnt signaling pathway is sufficient for de novo crypt formation, and suggest that different levels of canonical Wnt activations, in cooperation with Notch signaling, establish a hierarchy of slower-cycling stem cells and faster-cycling progenitor cells characteristic for the colonic epithelium.
Dose-dependent roles for canonical Wnt signalling in de novo crypt formation and cell cycle properties of the colonic epithelium.
Sex, Specimen part
View SamplesMulticellular organisms consist of multiple cell types, whose identities are maintained appropriately at locations where they are reside. The identity of each cell type is primarily maintained by cell-type-specific gene expression programs, but mechanisms that suppress these programs are poorly defined. Here we show that serum response factor (Srf), a transcription factor that is activated by various extracellular stimuli, can repress cell-type-specific genes and promote cellular reprogramming to pluripotency. Manipulations that decrease -actin monomer resulted in nuclear accumulation of Mkl1 and the activation of Srf, which downregulated cell-type-specific genes and altered epigenetics in enhancers and chromatin organization. Mice overexpressing Srf exhibited various pathologies including an ulcerative colitis-like symptom and a metaplasia-like phenotype in the pancreas. Our results demonstrate an unexpected function of Srf via a mechanism by which extracellular stimuli actively destabilize cell identity and suggest Srf involvement in a wide range of diseases.
Srf destabilizes cellular identity by suppressing cell-type-specific gene expression programs.
Specimen part
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