Project description:Reproducibility of expression patterns in iPSC-derived cells from different labs is an important first step in ensuring replication of biochemical or functional assays that are performed in different labs. Here we show that reproducible gene expression patterns from iPSCs and iPSC-derived neurons matured and collected at two separate laboratory locations can be achieved by closely matching protocols and reagents. While there are significant differences in gene expression between iPSCs and differentiated neurons, as well as between different donor lines of the same cell type, transcriptional changes that vary with laboratory sites are relatively small. These results suggest that making great efforts to match protocols, reagents and technical methods between labs may improve the reproducibility of iPSC-derived cell models.
Project description:Neuroblastoma is the most common extra cranial solid tumor derived from sympathoadrenal (SA) cells and characterized as either adrenergic or mesenchymal. Here, we compared four different protocols to differentiate induced pluripotent stem cells (iPSC) toward SA cells and intermediate cell states (neuromesodermal progenitors [NMP], trunk neural crest cells [tNCC]) as well as generating MYCN-driven tumors. Interestingly, the protocols that created cells with the highest level of NMP markers did not produce cells with the highest tNCC or SA cell markers. We identified a protocol that consistently produced cells with the highest level of SA markers using two iPSC lines of different genders. This protocol also generated tumors with the highest level of the neuroblastoma-specific marker, PHOX2B. Transcriptomally, however, each protocol generates tumors that resemble neuroblastoma. Two of the protocols repeatedly produced adrenergic neuroblastoma whereas the other two protocols were ambiguous. Thus, we identified a protocol that reliably generates adrenergic neuroblastoma.
Project description:Intestinal organoids accurately recapitulate epithelial homeostasis in vivo, thereby representing a powerful in vitro system to investigate lineage specification and cellular differentiation. Here, we applied a multi-omics framework on stem cell enriched and -depleted mouse intestinal organoids to obtain a holistic view of the molecular mechanisms that drive differential gene expression during adult intestinal stem cell differentiation. Our data revealed a global rewiring of the transcriptome and proteome between intestinal stem cells and enterocytes, with the majority of dynamic protein expression being transcription-driven. Integrating absolute mRNA and protein copy numbers revealed post-transcriptional regulation of gene expression. Probing the epigenetic landscape identified a large number of cell-type specific regulatory elements, which revealed Hnf4g as a major driver of enterocyte differentiation. In summary, by applying an integrative systems biology approach we uncovered multiple layers of gene expression regulation, which contribute to lineage specification and plasticity of the mouse small intestinal epithelium.
Project description:Hepatocyte-like cells (HLCs) were differentiated from induced pluripotent stem cells (iPSCs) using two different protocols and the genome-wide transcriptomic profile of the iPSC, HLCs and primary human hepatocytes were compared using Global Run-On sequencing (GRO-seq). In addition to protein coding genes, GRO-seq enabled identification of noncoding RNA species including primary miRNAs and long non-coding RNAs (lncRNAs). Altogether, 29 hub miRNAs that could regulate ~3000 target mRNAs related to regulation of transcription, translation, protein metabolism and cell cycle were identified. Alternative transcription start site (TSS) usage between the cell types was detected for several miRNA clusters. Additionally, HLC differentiation included extensive changes in lncRNA expression, which exhibited strong co-regulation with the protein-coding gene expression. Analysis of the motifs within regulated TSSs, allowed identification of transcription factors that might drive the transcriptional changes during hepatocyte differentiation.
Project description:Differentiation of pluripotent stem cells into lentoid bodies is important for the understanding of the lens development and investigating the processes critical for lens morphogenesis. This Study was initiated to investigate a comprehensive proteome profiling of the peripheral blood mononuclear cell (PBMC)-originated, induced pluripotent stem cell (iPSC)-derived lentoid bodies through mass spectrometry-based protein sequencing. Briefly, a small aliquot of blood sample was ascertained to collect PBMCs that were reprogrammed to iPSCs using the Sendai-virus delivery system. The PBMC-originated, iPSCs were differentiated into lentoid bodies employing the “fried egg” method using feeder-free conditions. The quantitative real-time PCR (qRT-PCR) confirmed the expression of lens-associated markers, which exhibited at least an order magnitude increased expression in lentoid bodies at differentiation day 35. Subsequently, the total cellular protein was extracted from lentoid bodies at day 35, digested with trypsin, fractionated into 96 fractions and subjected to an mass spectrometry-based label-free quantitative proteomics. mass spectrometry-based proteome profiling revealed 9,717 proteins in iPSC-derived lentoid bodies at differentiation day 35. In here, we report a comprehensive proteome of PBMC-originated, iPSC-derived lentoid bodies at day 35, which will help in better understanding processes critical for the development of the ocular lens.
Project description:Differentiation of pluripotent cells to generate lentoid bodies is important for the understanding of the lens development and investigating the processes critical for lens morphogenesis. This Study was initiated to investigate a comprehensive proteome profiling of the peripheral blood mononuclear cell (PBMC)-originated, induced pluripotent stem cell (iPSC)-derived lentoid bodies through mass spectrometry-based protein sequencing. Briefly, a small aliquot of blood sample was ascertained to collect PBMCs that were reprogrammed to iPSCs using the Sendai-virus delivery system. The PBMC-originated, iPSCs were differentiated into lentoid bodies employing the “fried egg” method using feeder-free conditions. The quantitative real-time PCR (qRT-PCR) confirmed the expression of lens-associated markers, which exhibited at least an order magnitude increased expression in lentoid bodies at differentiation day 25. Subsequently, the total cellular protein was extracted from lentoid bodies at day 25, digested with trypsin, fractionated into 24 fractions and subjected to an mass spectrometry-based label-free quantitative proteomics. mass spectrometry-based proteome profiling revealed 9,473 proteins in iPSC-derived lentoid bodies at differentiation day 25. In here, we report a comprehensive proteome of PBMC-originated, iPSC-derived lentoid bodies at day 25, which will help in better understanding processes critical for the development of the ocular lens.
Project description:Induced pluripotent stem cells (iPSCs) are a valuable resource for neurological disease-modeling and drug discovery, due to their ability to differentiate into neurons reflecting the genetics of the patient from which they are derived. iPSC-derived cultures, however, are highly variable due to differences in culture conditions. We investigated the effect of iPSC passage number on differentiation to optimize the generation of functional, mature sensory neurons (iPSC-dSNs). Three iPSC lines were differentiated into iPSC-dSNs at passage numbers within each of the following ranges: low (LP; 5-10), middle (MP; 20-26), and high (HP; 30-38). Morphology and pluripotency of the parent iPSCs were assessed prior to differentiation at each passage number. iPSC-dSNs were evaluated based on electrophysiological properties and expression of key neuronal markers. All iPSC lines displayed the same morphology and were similarly pluripotent across passage numbers. iPSC-dSNs were also morphologically comparable across passage numbers. However, the expression levels of neuronal markers and an analysis of sodium channel function indicated greater maturity in LP iPSC-dSNs. Our results demonstrate that lower passage numbers may be better suited for differentiation into peripheral sensory neurons. Further studies are warranted to elucidate factors that may contribute to the variability associated with iPSC passage number.