Similar Datasets
Project description:The four transcription factors OCT4, SOX2, KLF4 and MYC (OSKM) together can convert human fibroblasts to induced pluripotent stem cells (iPSCs). It is, however, perplexing that they can do so only for a rare population of the starting cells with a long latency. Transcription factors (TFs) define identities of both the starting fibroblasts and the end product, iPSCs, and are of paramount importance for the reprogramming process as well. It is critical to upregulate or activate iPSC-enriched TFs while downregulate or silence the fibroblast-enriched TFs. This report explores the initial TF responses to OSKM as the molecular underpinnings for both the potency aspect and limitation sides of the OSKM reprogramming. The author first defined the TF reprogramome, i.e., the full complement of TFs to be reprogrammed. Most TFs were resistant to OSKM reprogramming at the initial stages, which agrees with the inefficiency and long latency of iPSC reprogramming. Surprisingly, the current analyses revealed that the majority of the TFs (83 genes) that did respond to OSKM induction underwent legitimate reprogramming. The initial legitimate transcriptional responses of TFs to OSKM reprogramming were observed from fibroblasts from a different individual. Such early biased legitimate reprogramming of the responsive TFs aligns well with the robustness aspect of the otherwise inefficient and stochastic OSKM reprogramming
2020-12-08 | GSE159410 | GEO
Project description:To identify genes altered upon LIN-41 expression during reprogramming to induced pluripotent stem cells, human dermal fibroblasts were infected with combinations of GFP alone, OSK, OSKM, OSK+LIN-41, or OSK+let-7 inhibitor (transfected on days 1 and 6). After 11 days, TRA-1-60+ reprogramming cells were isolated as described in Tanabe et al 2013 or in the case of GFP-infected fibroblasts, GFP+ cells were collected. Total RNA was used for gene expression analysis. After 11 days of reprogramming with OSK, OSK+let-7inh, OSKM, or OSK+LIN-41, TRA-1-60+ cells were isolated and total RNA was isolated.
2013-11-20 | E-GEOD-52052 | biostudies-arrayexpress
Project description:Somatic cells can be directly reprogrammed to pluripotency by exogenous expression of transcription factors, classically Oct4, Sox2, Klf4 and c-Myc. While distinct types of somatic cells can be reprogramed with varying efficiencies and by different modified reprogramming protocols, induced pluripotent stem cell (iPSC) induction remains inefficient and stochastic where a fraction of the cells converts into iPSCs. The nature of rate limiting barrier(s) preventing majority of cells to convert into iPSCs remains elusive. Here we show that neutralizing Mbd3, a core member of the Mbd3/NURD co-repressor and chromatin-remodeling complex, results in deterministic and synchronized reprogramming of multiple differentiated cell types to pluripotency. 100% of Mbd3 depleted mouse and human somatic cells convert into iPSCs after seven days of reprogramming factor induction. Our findings delineate a critical pathway blocking the reestablishment of pluripotency, and offer a novel platform for future dissection of epigenetic dynamics leading to iPSC formation at high resolution. Reduced representation bisulfite sequencing (RRBS) was applied to mouse iPS cells and mouse embryonic fibroblast (MEF) before and after DOX induction (initiating reprogramming by OSKM factors) from randomly selected Mbd3+/+ and Mbd3flox/- clonal cell line series. Polyclonal donor cell cultures were harvested at days 0,4 and 8 after DOX reprogramming without selection or sorting for any marker or passaging, and mapped for similarity to subcloned iPSC lines.
2014-12-13 | E-GEOD-64115 | biostudies-arrayexpress
Project description:Somatic cells can be directly reprogrammed to pluripotency by exogenous expression of transcription factors, classically Oct4, Sox2, Klf4 and c-Myc. While distinct types of somatic cells can be reprogramed with varying efficiencies and by different modified reprogramming protocols, induced pluripotent stem cell (iPSC) induction remains inefficient and stochastic where a fraction of the cells converts into iPSCs. The nature of rate limiting barrier(s) preventing majority of cells to convert into iPSCs remains elusive. Here we show that neutralizing Mbd3, a core member of the Mbd3/NURD co-repressor and chromatin-remodeling complex, results in deterministic and synchronized reprogramming of multiple differentiated cell types to pluripotency. 100% of Mbd3 depleted mouse and human somatic cells convert into iPSCs after seven days of reprogramming factor induction. Our findings delineate a critical pathway blocking the reestablishment of pluripotency, and offer a novel platform for future dissection of epigenetic dynamics leading to iPSC formation at high resolution. Samples include Mbd3+/+, Mbd3flox/- and Mbd3-/- cells from mouse ES cells and mouse embryonic fibroblast (MEF) before and after DOX induction (initiating reprogramming by OSKM factors).
2013-09-12 | E-GEOD-45352 | biostudies-arrayexpress
Project description:Induced pluripotent stem cells (iPSCs) are commonly generated by transduction of Oct4, Sox2, Klf4 and Myc (OSKM) into somatic cells. Though iPSCs are pluripotent, they frequently exhibit high variation in their quality as measured by chimera contribution and tetraploid (4n) complementation. Thus, improving the quality of iPSCs is an indispensable prerequisite for future iPSC-based therapy. Here we show that one major determinant for iPSCs quality is the selection of the reprogramming factors combination. Ectopic expression of Sall4, Nanog, Esrrb and Lin28 (SNEL) in MEFs efficiently generated high quality iPSCs as compared to other combinations of factors. SNEL-iPSCs produced approximately 5 times more efficiently “all-iPSC” mice compared to OSKM-iPSCs. While differentially methylated regions, transcript number of master regulators, establishment of ESC-specific super enhancers, and global aneuploidy were comparable between the lines, aberrant expression of 1,765 genes, trisomy of chromosome 8 and abnormal H2A.X deposition were frequently observed in poor quality OSKM-iPSCs. For high-quality iPSCs, H2A.X pattern of SNEL is most similar to that of ESC, OSK and OSKM have more devoid regions than SNEL iPSCs. Compare H2A.X deposition pattern of the OSKM 4-factor iPS cell lines (4N-), SNEL 4-factor iPS cell lines (4N+) with ChIP-Seq. The same background ES cell line as the control line.
2014-09-07 | E-GEOD-55731 | biostudies-arrayexpress
Project description:Somatic cells can be directly reprogrammed to pluripotency by exogenous expression of transcription factors, classically Oct4, Sox2, Klf4 and c-Myc. While distinct types of somatic cells can be reprogramed with varying efficiencies and by different modified reprogramming protocols, induced pluripotent stem cell (iPSC) induction remains inefficient and stochastic where a fraction of the cells converts into iPSCs. The nature of rate limiting barrier(s) preventing majority of cells to convert into iPSCs remains elusive. Here we show that neutralizing Mbd3, a core member of the Mbd3/NURD co-repressor and chromatin-remodeling complex, results in deterministic and synchronized reprogramming of multiple differentiated cell types to pluripotency. 100% of Mbd3 depleted mouse and human somatic cells convert into iPSCs after seven days of reprogramming factor induction. Our findings delineate a critical pathway blocking the reestablishment of pluripotency, and offer a novel platform for future dissection of epigenetic dynamics leading to iPSC formation at high resolution. Samples include Mbd3+/+, Mbd3flox/- and Mbd3-/- cells from mouse ES cells and mouse embryonic fibroblast (MEF) before and after DOX induction (initiating reprogramming by OSKM factors). Two histone modifications are given: H3K4me3, H3K27me3. In addition binding data of Mbd3 and Mi2B in various stages.
2013-09-12 | E-GEOD-49766 | biostudies-arrayexpress
Project description:To identify genes altered upon LIN-41 expression during reprogramming to induced pluripotent stem cells, human dermal fibroblasts were infected with combinations of GFP alone, OSK, OSKM, OSK+LIN-41, or OSK+let-7 inhibitor (transfected on days 1 and 6). After 11 days, TRA-1-60+ reprogramming cells were isolated as described in Tanabe et al 2013 or in the case of GFP-infected fibroblasts, GFP+ cells were collected. Total RNA was used for gene expression analysis.
2013-11-20 | GSE52052 | GEO
Project description:C/EBPα induces transdifferentiation of B cells into macrophages at high efficiencies and enhances reprogramming into induced pluripotent stem cells (iPSCs) when co-expressed with Oct4, Sox2, Klf4 and Myc (OSKM). However, how C/EBPα accomplishes these effects is unclear. We now found that transient C/EBPα expression followed by OSKM activation induces a 100 fold increase in iPSC reprogramming efficiency, involving 95% of the cells. During this conversion pluripotency and epithelial-mesenchymal transition genes become dramatically up-regulated and 60% of the cells express Oct4 within 2 days. C/EBPα acts as a pathbreaker since it transiently makes the chromatin of pluripotency genes more accessible to DNase I. It also induces the expression of the dioxygenase Tet2 and promotes its translocation to the nucleus where it binds to regulatory regions of pluripotency genes that become demethylated following OSKM induction. In line with these findings, overexpression of Tet2 enhances OSKM‐induced B cell reprogramming. Since the enzyme is also required for efficient C/EBPα-induced immune cell conversion, our data suggest that Tet2 provides a mechanistic link between iPSC reprogramming and B cell transdifferentiation. The rapid iPS reprogramming approach described should help to fully elucidate the process and has potential clinical applications. Change in Cebpa genome binding/occupancy, comparing primary B-cells treated with estradiol for 18h to induce C/EBPa to untreated cells.
2013-11-17 | E-GEOD-52373 | biostudies-arrayexpress
Project description:C/EBP? induces transdifferentiation of B cells into macrophages at high efficiencies and enhances reprogramming into induced pluripotent stem cells (iPSCs) when co-expressed with Oct4, Sox2, Klf4 and Myc (OSKM). However, how C/EBP? accomplishes these effects is unclear. We now found that transient C/EBP? expression followed by OSKM activation induces a 100 fold increase in iPSC reprogramming efficiency, involving 95% of the cells. During this conversion pluripotency and epithelial-mesenchymal transition genes become dramatically up-regulated and 60% of the cells express Oct4 within 2 days. C/EBP? acts as a pathbreaker since it transiently makes the chromatin of pluripotency genes more accessible to DNase I. It also induces the expression of the dioxygenase Tet2 and promotes its translocation to the nucleus where it binds to regulatory regions of pluripotency genes that become demethylated following OSKM induction. In line with these findings, overexpression of Tet2 enhances OSKM?induced B cell reprogramming. Since the enzyme is also required for efficient C/EBP?-induced immune cell conversion, our data suggest that Tet2 provides a mechanistic link between iPSC reprogramming and B cell transdifferentiation. The rapid iPS reprogramming approach described should help to fully elucidate the process and has potential clinical applications. Change in gene expression, comparing primary B-cells treated with estradiol for 18h to induce C/EBPa to untreated cells.
2013-11-17 | E-GEOD-52396 | biostudies-arrayexpress
Project description:Induced pluripotent stem cells (iPSCs) are commonly generated by transduction of Oct4, Sox2, Klf4 and Myc (OSKM) into somatic cells. Though iPSCs are pluripotent, they frequently exhibit high variation in their quality as measured by chimera contribution and tetraploid (4n) complementation. Thus, improving the quality of iPSCs is an indispensable prerequisite for future iPSC-based therapy. Here we show that one major determinant for iPSCs quality is the selection of the reprogramming factors combination. Ectopic expression of Sall4, Nanog, Esrrb and Lin28 (SNEL) in MEFs efficiently generated high quality iPSCs as compared to other combinations of factors. SNEL-iPSCs produced approximately 5 times more efficiently “all-iPSC” mice compared to OSKM-iPSCs. While differentially methylated regions, transcript number of master regulators, establishment of ESC-specific super enhancers, and global aneuploidy were comparable between the lines, aberrant expression of 1,765 genes, trisomy of chromosome 8 and abnormal H2A.X deposition were frequently observed in poor quality OSKM-iPSCs. For high-quality iPSCs, H2A.X pattern of SNEL is most similar to that of ESC, OSK and OSKM have more devoid regions than SNEL iPSCs.
2014-09-07 | GSE55731 | GEO