Oct3/4, 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.
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View SamplesThis study explored the role of the growth hormone (GH) / insulin-like growth factor 1 (IGF-1) axis on the life-long caloric restriction (CR)-associated remodeling of white adipose tissue (WAT). Adipocyte size and gene expression profiles, using high-density oligonucleotide microarrays, were analyzed in WAT of six- to seven-month old wild Wistar rats fed ad libitum (AL) or subjected to a 30% caloric restriction (CR), and heterozygous transgenic dwarf rats bearing an anti-sense GH transgene fed ad libitum (Tg). While not significant in Tg rats, adipocyte size was significantly reduced in CR rats compared with AL rats. The microarray data based on the principal component analysis demonstrated that the gene expression profile of CR rats markedly differed from the AL rats, while Tg hardly differed, suggesting that CR-associated WAT remodeling was predominantly regulated in a GH/IGF-1-independent manner. The gene cluster with the largest change induced by CR included several genes involved in lipid biosynthesis and inflammation. Moreover, many of the genes transcriptionally regulated by sterol regulatory element binding proteins (SREBPs) were found in the cluster related to lipid biosynthesis. Real-time reverse transcription polymerase chain reaction analysis confirmed that the expression of SREBP-1 and its down-stream targets was particularly up-regulated in CR rats compared with SREBP-2 and its down-stream targets. Our findings suggest that SREBP-1 is a major transcription factor in CR-associated remodeling of WAT, and might be one of the key regulators of the anti-aging and pro-longevity effects of CR.
Caloric restriction-associated remodeling of rat white adipose tissue: effects on the growth hormone/insulin-like growth factor-1 axis, sterol regulatory element binding protein-1, and macrophage infiltration.
Age, Specimen part
View SamplesWe have examined the biological effect of EWS/ETS in human MPCs using UET-13 cells that are obtained by prolonging the lifespan of human bone marrow stromal cells using the retroviral transgenes hTERT and E7. By exploiting tetracycline-inducible systems for expressing EWS/ETS (EWS/FLI1 and EWS/ERG), we investigated candidates for genes whose expression is regulated by EWS/ETS in human MPCs.
Inducible expression of chimeric EWS/ETS proteins confers Ewing's family tumor-like phenotypes to human mesenchymal progenitor cells.
No sample metadata fields
View SamplesFor identification of candidate genes that is specifically expressed in Ewing family tumor (EFT) cells, we performed DNA microarray-based global expression profiling using Affymetrix Human Genome U133 Plus 2.0 Array and analyxed expression profiles from EFT cell lines (7 lines), neuroblastoma (NB) cell lines (3 lines), a Rhabdomyosarcoma (RMS) cell line, and a human immortalized mesenchymal progenitor cells UET-13 cells.
Inducible expression of chimeric EWS/ETS proteins confers Ewing's family tumor-like phenotypes to human mesenchymal progenitor cells.
No sample metadata fields
View SamplesThe pancreatic beta cells are the only cells that can produce insulin in response to prevailing glycemia. The development of beta cells was found to be depending on the activity of a complex genetic network. Overexpression of transcriptional factor MafK in beta cells have resulted in impairment of thier functions and suppressed insulin secretion and increased the severity of beta cell loss resulting in an overt diabetes.
β-Cell-Specific Mafk Overexpression Impairs Pancreatic Endocrine Cell Development.
Specimen part
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 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
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Premature termination of reprogramming in vivo leads to cancer development through altered epigenetic regulation.
Specimen part
View SamplesWe report a reprogrammable mouse system in which reprogramming factor expression in vivo can be controlled temporally by treatment with doxycycline (Dox). Transient expression of reprogramming factors in vivo results in tumor development in various tissues, consisting of undifferentiated dysplastic cells. We analyzed the kidney tumors developed in reprogrammable mice for global gene expressions and DNA methylations.
Premature termination of reprogramming in vivo leads to cancer development through altered epigenetic regulation.
Specimen part
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