Genome-wide analysis of pluripotency marker expression of ESKM-iPS cells
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ABSTRACT: iPS cells, produced in in presence of exogeneously expressed E-cadherin and abcence of viral Oct4 were compared with conventional produced OSKM-iPS cells and murine embryonic stem cells (mESCs) or MEFs
Project description:iPS cells, produced in in presence of exogeneously expressed E-cadherin and abcence of viral Oct4 were compared with conventional produced OSKM-iPS cells and murine embryonic stem cells (mESCs) or MEFs Total RNA was isolated from iPSCs and mESCs grown in presence of LIF on gelatin-coated plates for 4 days and from murine embryonic fibroblasts grown in standard medium (DMEM-Glutamax, high-glucose, 10 % FBS, 1X non-essential amino acids, penicillin/ streptomycin
Project description:E-cadherin upregulation is an early event of reprogramming of fibroblasts to induce pluripotent stem cells (iPS). Knocking down of E-cadherin by shRNA impairs iPS generation, though some colonies with great morphorlogical difference to shRNA control colonies remain. To illustrate the molecular and functional difference between shECAD iPS clones and shRNA control iPS clones, three respective iPS clones (shECAD 4,8,9 and Ctrl 2,3,4) were derived and DNA microarrays were run to analyze the transcriptional profile of these clones. OG2 MEFs were infected with Sox2, Klf4, Oct4 and c-Myc (SKOM) plus either Luciferase shRNA (shLUC) or E-cadherin shRNA (shECAD) retrovirus. At Day 6 post infection cells were split onto feeder cells. Several colonies from SKOM+shLuc and SKOM+shECAD were picked out at Day 14 post infection respectively and three cell lines were established, namely Ctrl 2,3,4 for SKOM+shLuc iPS and shECAD 4,8,9 for SKOM+shECAD iPS. All clones were maintained on feeder cells in mESC medium. RNA were extracted from these six cell lines and DNA microarrays were run to analyze the transcriptional profile.
Project description:AIM: To detect differences in transcriptional profiles after knocking down Ncor1 or Oct4, compared to a negative control in early reprogramming to pluripotency. DESCRIPTION: RNA-seq profiles of early reprogramming mouse embryonic fibroblasts (MEFs) transduced with lentivirus containing doxycycline-inducible OSKM factors to induce pluripotency . Before starting reprogramming, OSKM-MEFs were transfected with different siRNAs and then they were reprogrammed for 3 or 6 days.
Project description:6C secondary MEFs were treated with Dox in mES media to turn on the Oct4, Klf4, cMyc, Sox2. Total RNA was extracted at day 0 (no Dox), day2, 5, 8, 11, 16 and 21 (with Dox) and day 30 (Dox-independent secondary iPS). RNA from Parental MEFs and Primary-iPS cells were also extracted for reference. 1B secondary MEFs were Dox treated for 5-days followed by RNA extraction. Subsequently, a culture removed of Dox treatment for an additional 5days was also analyzed.
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.
Project description:Derivation and maintenance of pluripotent stem cells (PSCs) including embryonic stem cells(ESCs) and (iPSCs) usually requires optimization of complex culture media, which hinders the generation of PSCs from various species. Expression of Oct4, Sox2, Klf4 and c-Myc (OSKM) can reprogram somatic cells into iPSCs, even for species possessing no optimal culture condition. Here we explored whether expression of OSKM could induce and maintain pluripotency without specific growth factors and signaling inhibitors. Tet-On-OSKM/Oct4-GFP Mouse ESCs (mESCs) were derived from the embryos obtained after mating of Tet-On-OSKM mouse and Oct4-GFP mouse under the 2iL ( N2B27 plus MEK inhibitor PD0325901, GSK3β inhibitor ChIR99021, and leukemia inhibitory factor) condition. Tet-On-OSKM mouse was Gt(ROSA)26Sor tm1(rtTA*M2)Jae Col1a1 tm3(tetO-Pou5f1,-Sox2,-Klf4,-Myc)Jae/J(The Jackson Laboratory,011004), and Oct4-GFP mouse was B6;CBA-Tg(Pou5f1-EGFP)2Mnn/J (The Jackson Laboratory,004654).The culture medium of Tet-On-OSKM/Oct4-GFP mouse ESCs was switched from 2iL to N2B27 plus Doxycycline medium (OSKM medium), under which OSKM trangene was activated. These above cells switched from 2iL to OSKM medium were called OSKM-ESCs. Meanwhile 2iL-ESCs (continuely cultured in 2iL) served as the positive control group. 2iL-ESCs and OSKM-ESCs collected at selective days (d18, 25 and 38) after medium switch were collected for RNA-Seq. Moreover, Tet-On-OSKM mouse embryonic fibroblast (MEF) cells were reprogrammed under OSKM medium (N2B27 plus Doxycycline) and 2iL medium, respectively. The resulting OSKM-iPSCs were reprogrammed and cultured under OSKM medium.The 2iL-iPSCs were reprogrammed under 2iL plus Doxycycline medium and cultured under 2iL medium (without Doxycycline)once clones were picked up.RNA-Seq of these above samples was conducted to analyze gene expression. We found that via continuous expression of OSKM,OSKM-ESCs and OSKM-iPSCs propagated stably, expressed pluripotency marker genes, and formed three germ layers in teratomas. Importantly, OSKM-iPSCs could produce gene-modified animals through germline transmission.Transcriptional landscapes of OSKM-iPSCs resembled 2iL-ESCs, and were more similar to those of ESCs cultured in serum/LIF.
Project description:we generate iPSCs from a common fibroblast cell source using either the Yamanaka factors (OCT4, SOX2, KLF4 and MYC) or the Thomson factors (OCT4, SOX2, NANOG and LIN28) and determined their genome-wide DNA methylation profiles. In addition to shared DNA methylation aberrations present in all our iPSCs, we identify Yamanaka-iPSC (Y-iPSCs)-specific and Thomson-iPSCs (T-iPSC)-specific recurrent aberrations. Bisulphite converted DNA from 9 iPS cells derived using Yamanaka factors (OSKM), 6 iPS cells derived using Thompson factors (OSLN), 2 parental fibroblasts and one embrionic ES cell were hybridised to the Illumina Infinium 450k Human Methylation Beadchip
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.
Project description:We were able to achieve an initial stable intermediate phase by the transduction of Oct4, Klf4, and c-Myc. Furthermore, over-expression of Sox2 in these intermediate stage cells leads to final iPS cell phase. After examining the gene expression profiles from the initial to final iPS cell phases, we have identified Sox2 downstream genes important for iPS cell induction. 4 groups of cells are analyzed. Each group contains cells from 4 indepent dishes. The four groups are: ES cells, iPS cells, intermediate stage cells (OKM cells) and MEFs
Project description:E-cadherin upregulation is an early event of reprogramming of fibroblasts to induce pluripotent stem cells (iPS). Knocking down of E-cadherin by shRNA impairs iPS generation, though some colonies with great morphorlogical difference to shRNA control colonies remain. To illustrate the molecular and functional difference between shECAD iPS clones and shRNA control iPS clones, three respective iPS clones (shECAD 4,8,9 and Ctrl 2,3,4) were derived and DNA microarrays were run to analyze the transcriptional profile of these clones.