Project description:Assessing relevant molecular differences between human-induced pluripotent stem cells (hiPSCs) and human embryonic stem cells (hESCs) is important, given that such differences may impact their potential therapeutic use. Controversy surrounds recent gene expression studies comparing hiPSCs and hESCs. Here, we present an in-depth quantitative mass spectrometry-based analysis of hESCs, two different hiPSCs and their precursor fibroblast cell lines. Our comparisons confirmed the high similarity of hESCs and hiPSCS at the proteome level as 97.8% of the proteins were found unchanged. Nevertheless, a small group of 58 proteins, mainly related to metabolism, antigen processing and cell adhesion, was found significantly differentially expressed between hiPSCs and hESCs. A comparison of the regulated proteins with previously published transcriptomic studies showed a low overlap, highlighting the emerging notion that differences between both pluripotent cell lines rather reflect experimental conditions than a recurrent molecular signature. See the Data Processing section of the published paper concerning the bioinformatics pipeline used. PMCID: PMC3261715 PMID: 22108792 Mol Syst Biol. 2011 Nov 22;7:550. doi: 10.1038/msb.2011.84. The quantitative proteomes of human-induced pluripotent stem cells and embryonic stem cells. Munoz J, Low TY, Kok YJ, Chin A, Frese CK, Ding V, Choo A, Heck AJ. Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, The Netherlands.
Project description:Differentiation of mammalian pluripotent cells involves large-scale changes in transcription and, among the molecules that orchestrate these changes, chromatin remodellers are essential to initiate, establish and maintain a new gene regulatory network. The NuRD complex is a highly conserved chromatin remodeller which fine-tunes gene expression in embryonic stem cells. While the function of NuRD in mouse pluripotent cells has been well defined, no study yet has defined NuRD function in human pluripotent cells. We investigated the structure and function of NuRD in human induced pluripotent stem cells (hiPSCs). Using immunoprecipitation followed by mass-spectrometry in hiPSCs and in naive or primed mouse pluripotent stem cells, we find that NuRD structure and biochemical interactors are generally conserved. Using RNA sequencing, we find that, whereas in mouse primed stem cells and in mouse naive ES cells, NuRD is required for an appropriate level of transcriptional response to differentiation signals, hiPSCs require NuRD to initiate these responses. This difference indicates that mouse and human cells interpret and respond to induction of differentiation differently.
Project description:The equivalency of human induced pluripotent stem cells (hiPSCs) with human embryonic stem cells (hESCs) remains controversial. Here, we devised a strategy to assess the contribution of clonal growth, reprogramming method and genetic background to transcriptional patterns in hESCs and hiPSCs. Surprisingly, transcriptional variation originating from two different genetic backgrounds was dominant over variation due to the reprogramming method or cell type of origin of pluripotent cell lines. Moreover, the few differences we detected between isogenic hESCs and hiPSCs neither predicted functional outcome, nor distinguished an independently derived, larger set of unmatched hESC/hiPSC lines. We conclude that hESCs and hiPSCs are transcriptionally and functionally highly similar and cannot be distinguished by a consistent gene expression signature. Our data further imply that genetic background variation is a major confounding factor for transcriptional comparisons of pluripotent cell lines, explaining some of the previously observed expression differences between unmatched hESCs and hiPSCs. Expression profiling of human embryonic stem cells (ESCs), induced pluripotent stem cells (iPSCs) and fibroblasts, mostly in triplicates.
Project description:We developed a strategy to generate cardiac progenitor cells from human induced pluripotent stem cells using a novel small molecule.miRNA-sequencing results showed different miRNA expression profile among undifferentiated human induced pluripotent stem cells(hiPSCs), DMSO and ISX-9 treated hiPSCs.In comparsion with DMSO treated cells, ISX-9 upregulated several myogenic miRNAs and cardiac hypertrophy related-miRNAs including miR-335, miR-21, miR-30c,miRNA-181a and miR-214.
Project description:To gain insight into the molecular regulation of human heart development, a detailed comparison of the mRNA and miRNA transcriptomes across differentiating human-induced pluripotent stem cell (hiPSC)–derived cardiomyocytes and biopsies from fetal, adult, and hypertensive human hearts was performed. Gene ontology analysis of the mRNA expression levels of the hiPSCs differentiating into cardiomyocytes revealed 3 distinct groups of genes: pluripotent specific, transitional cardiac specification, and mature cardiomyocyte specific. Hierarchical clustering of the mRNA data revealed that the transcriptome of hiPSC cardiomyocytes largely stabilizes 20 days after initiation of differentiation. Nevertheless, analysis of cells continuously cultured for 120 days indicated that the cardiomyocytes continued to mature toward a more adult-like gene expression pattern. Analysis of cardiomyocyte-specific miRNAs (miR-1, miR-133a/b, and miR-208a/b) revealed a miRNA pattern indicative of stem cell to cardiomyocyte specification. A biostatistitical approach integrated the miRNA and mRNA expression profiles revealing a cardiomyocyte differentiation miRNA network and identified putative mRNAs targeted by multiple miRNAs. Together, these data reveal the miRNA network in human heart development and support the notion that overlapping miRNA networks re-enforce transcriptional control during developmental specification. miRNA expression profiling of differentiating human-induced pluripotent stem cell (hiPSC)–derived cardiomyocytes (days 0-120)
Project description:Here, human induced pluripotent stem cells (control-hiPSCs, CMT1A-hiPSCs, and PMP22-hiPSCs) were induced to differentiate to Schwann cells (control-SCs, CMT1A-SCs, and PMP22-SCs) through neural crest stage (control-NCSCs, CMT1A-NCSCs, and PMP22-NCSCs). We sequenced mRNA samples from Schwann cell differentiation of human pluripotent stem cells at 3 different stage to generate the gene expression profiles of these cells.
Project description:<p>The iPSCORE Resource of human induced pluripotent stem cells (hiPSCs) was created as part of the Next-Gen Consortium funded by the NHLBI. The overarching purpose of the iPSCORE Resource is to provide a large collection of hiPSCs for use in studying the impact of genetic variation on molecular and physiological phenotypes. This Resource is being used in a number of ongoing studies for which genomic data will be generated and deposited into public repositories and linked through dbGaP. A total of 273 individuals have participated in the study for which 222 have had hiPSCs generated from fibroblasts (available through WiCell (<a href="http://www.wicell.org/" target="_blank">http://www.wicell.org/</a>)). Of the 273 individuals, 181 are part of 55 families that include 24 monozygotic twin pairs and 5 dizygotic twin pairs, allowing for the incorporation of familial relationships into genetic analyses. Germline DNA has been sequenced from blood or fibroblast samples for all 273 individuals (see <a href="./study.cgi?study_id=phs001325">phs001325</a>) and other genomic data (RNA-seq, DNA methylation, and genotype arrays) has been generated from the 222 hiPSCs derived from a subset of these individuals (phs000924). Current studies include differentiation of these hiPSCs to other cell types, including cardiomyocytes and retinal pigment epithelium, and the generation of additional genomic data.</p>