Project description:We examined genome-wide DNA methylation with 20 human iPSC lines derived from five different cell types,and 7 human ESC lines using Illumina’s Infinium HumanMethylation450K and compared among iPSCs by retrovirus, Sendai virus or episomal vectors.
Project description:Human induced pluripotent stem cells (iPSCs) are established by introducing several reprogramming factors, such as OCT3/4, SOX2, KLF4, c-MYC. Because of their pluripotency and immortality, iPSCs are considered to be a powerful tool for regenerative medicine. To date, iPSCs have been established all over the world by various gene delivery methods. All methods induced high-quality iPSCs, but epigenetic analysis of abnormalities derived from differences in the gene delivery methods has not yet been performed. Here, we generated genetically matched human iPSCs from menstrual blood cells by using three kinds of vectors, i.e., retrovirus, Sendai virus, and episomal vectors, and compared genome-wide DNA methylation profiles among them. Although comparison of aberrant methylation revealed that iPSCs generated by Sendai virus vector have lowest number of aberrant methylation sites among the three vectors, the iPSCs generated by non-integrating methods did not show vector-specific aberrant methylation. However, the differences between the iPSC lines were determined to be the number of random aberrant hyper-methylated regions compared with embryonic stem cells. These random aberrant hyper-methylations might be a cause of the differences in the properties of each of the iPSC lines.
Project description:We generated hiPSCs from patients fibloblast with retinitis pigmentosa (RP) using retrovirus and Sendai virus vectors, which we differentiated into hiPSC derived retinal pigment epithelium using two different methods (SDIA and SFEB methods). We investigated whether these hiPSC-RPE colonies, which were differentiated from various cell lines and methods, showed similar gene expression patterns to those of native RPE.
Project description:Recent studies demonstrated that fibroblasts could be converted into induced neural stem cells (iNSCs). However, the insertional mutation caused by random integration of viral vectors has been a major limitation of iNSCs for the future clinical translation. Here we show that non-viral transfection of episomal vectors encoding Brn4/Pou3f4, Sox2, Klf4, and c-Myc sufficiently generates iNSCs. The episomal vector mediated iNSCs closely resemble brain-derived NSCs as well as iNSCs generated by retrovirus in morphology, gene expression profile, epigenetic status, self-renewal capacity and both in vitro and in vivo differentiation capacity. The novel conversion protocol defined in the current study offers a method for generating integration-free iNSCs for the clinical research we developed a novel method for generating integration-free iNSCs. We demonstrated that oriP/EBNA1-based episomal vectors could generate iNSCs by single transfection
Project description:Recent studies demonstrated that fibroblasts could be converted into induced neural stem cells (iNSCs). However, the insertional mutation caused by random integration of viral vectors has been a major limitation of iNSCs for the future clinical translation. Here we show that non-viral transfection of episomal vectors encoding Brn4/Pou3f4, Sox2, Klf4, and c-Myc sufficiently generates iNSCs. The episomal vector mediated iNSCs closely resemble brain-derived NSCs as well as iNSCs generated by retrovirus in morphology, gene expression profile, epigenetic status, self-renewal capacity and both in vitro and in vivo differentiation capacity. The novel conversion protocol defined in the current study offers a method for generating integration-free iNSCs for the clinical research
Project description:Genome instability is a potential limitation to the research and therapeutic application of induced pluripotent stem cells (iPSCs). Observed genomic variations reflect the combined activities of DNA damage, cellular DNA damage response (DDR), and selection pressure in culture. To understand the contribution of DDR on the distribution of copy number variations (CNVs) in iPSCs, we mapped CNVs of iPSCs with mutations in the central DDR gene ATM onto genome organization landscapes defined by genome-wide replication timing profiles. We show that following reprogramming the early and late replicating genome is differentially affected by CNVs in ATM deficient iPSCs relative to wild type iPSCs. Specifically, the early replicating regions had increased CNV losses during retroviral reprogramming. This differential CNV distribution was not present after later passage or after episomal reprogramming. Comparison of different reprogramming methods in the setting of defective DNA damage response reveals unique vulnerability of early replicating open chromatin to retroviral vectors. We isolated genomic DNA from Ataxia-telangiectasia (A-T) iPSC cells derived from patient fibroblasts virus and episomal vectors, coresponding fibroblasts, normal human fibroblast derived iPSCcells, for hybridization to the Affymetrix Genome-Wide Human SNP 6.0 Array.
Project description:Induced pluripotent stem cells (iPSCs) are a valuable resource in veterinary regenerative medicine and cellular therapy, particularly for advancing species-specific applications such as feline medicine. This study employs RNA sequencing (RNA-seq) to investigate the transcriptomic profiles of feline iPSCs generated using the Sendai virus method and mesenchymal stem cells (MSCs) derived from these iPSCs. The comparative analysis reveals unique expression patterns linked to the Sendai virus reprogramming approach, identifying key regulatory pathways and gene networks characteristic of Sendai virus-derived iPSCs. Furthermore, the distinct transcriptome of iPSC-derived MSCs showcases markers associated with mesenchymal lineage commitment and MSC functionality. These findings provide valuable insights into the impact of Sendai virus reprogramming on feline iPSC properties and contribute to advancing stem cell-based therapies tailored to feline-specific needs.
Project description:We generated hiPSCs from patients fibloblast with retinitis pigmentosa (RP) using retrovirus and Sendai virus vectors, which we differentiated into hiPSC derived retinal pigment epithelium using two different methods (SDIA and SFEB methods). We investigated whether these hiPSC-RPE colonies, which were differentiated from various cell lines and methods, showed similar gene expression patterns to those of native RPE. We classified hiPSC-RPE, hiPSCs, and fibroblasts from RP patients, hRPE (commercially available human fetal RPE, Lonza) , ARPE19 (a human RPE cell line), and other human tissues from 54,675 probe sets using microarray data.
Project description:Transient expression of two factors, or from Oct4 alone, resulted in efficient generation of human iPSCs. The reprogramming strategy described revealed a potential transcriptional signature for human iPSCs yet retaining the gene expression of donor cells in human reprogrammed cells free of viral and transgene interference. Genetic reprogramming of somatic cells to a pluripotent state (induced pluripotent stem cells or iPSCs) by over-expression of specific genes has been accomplished using mouse and human cells. However, it is still unclear how similar human iPSCs are to human Embryonic Stem Cells (hESCs). Here, we describe the transcriptional profile of human iPSCs generated without viral vectors or genomic insertions, revealing that these cells are in general similar to hESCs but with significant differences. For the generation of human iPSCs without viral vectors or genomic insertions, pluripotent factors Oct4 and Nanog were cloned in episomal vectors and transfected into human fetal neural progenitor cells. The transient expression of these two factors, or from Oct4 alone, resulted in efficient generation of human iPSCs. The reprogramming strategy described here revealed a potential transcriptional signature for human iPSCs yet retaining the gene expression of donor cells in human reprogrammed cells free of viral and transgene interference. Moreover, the episomal reprogramming strategy represents a safe way to generate human iPSCs for clinical purposes and basic research.