Single nucleus RNA sequencing of human iPSC-derived forebrain organoids to assay cell type composition
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ABSTRACT: Human iPSC line D1 was differentiated into spheroids. After 21 weeks in culture, single nucei were extracted and assayed using single nucleus RNA sequencing to characterize the spheroids' cell type composition.
Project description:Our purpose was to investigate genes and molecular mechanisms involved in patients with Leber congenital amaurosis (LCA). Fibroblasts from two unrelated clinically-identified patients (Coriell) were reprogrammed to pluripotency by retroviral transduction. These human induced Pluripotent Stem Cells (hiPSCs) were differentiated into neural stem cells (NSC) that mimicked the neural tube stage and retinal pigmented epithelial (RPE) cells that could be targeted by the disease. A genome wide transcriptome analysis was performed with Affymetrix Exon Array GeneChipM-BM-., comparing LCA-hiPSCs derivatives to controls. The aim was to identify differentially expressed genes which may be associated with early developmental defect before the establishment of mature retinal circuitry. We analyzed iPSC-derived neural stem cells from LCA patient's fibroblast (n=2) and iPSC-derived neural stem cells from healthy people fibroblast (n=2). A total of 21 samples were analyzed : 9 NSC derived from iPSC LCA and 12 NSC derived from wild-type iPSC.
Project description:RNAseq data indicate that in the human brain, most neurons co-express the brain-derived neurotrophic factor (BDNF) receptor TrkB and the Neurotrophin-3 (NT3) receptor TrkC. Because NT3 can also activate TrkB and TrkB is expressed at higher levels compared with TrkC, it has been difficult thus far to explore TrkC-mediated signaling. To this end, neurons were generated from human embryonic stem cells lacking the BDNF receptor TrkB using CRISPR/Cas9. These neurons were found to respond to very low concentrations of NT3, lower than the concentrations of BDNF needed to activate TrkB. In order to compare the transcriptional changes following treatment with NT3 RNA-seq analysis was performed and the results compared with those previously obtained following treatment of wild-type neurons with BDNF Merkouris et al. PMID: 29987039. The results indicate that downstream of TrkC activation, most of the changes in gene expression are similar to those seen after TrkB activation. The results also show that exposure to sub-saturating concentrations of either BDNF or NT3 does not cause receptor downregulation as seen with saturating ligand concentrations and that the receptors can be re-activated.
Project description:We performed RNA-seq experiments on two samples (cortical neurons and spinal motor neurons) from normal induced pluripotent stem cells (iPSCs), and another two samples (cortical neurons and spinal motor neurons) derived from SPG3A (an early onset form of hereditary spastic paraplegia) iPSCs. This initial experiment is to test the system and set up a baseline for future studies. Cortical projection neurons and spinal motor neurons were differentiated from same batch of iPSCs in parallel to minimize variations. The differentiation of cortical neurons and spinal motor neurons are based on protocols well-established in our group.
Project description:To investigate the effects of ZIKV infection or ZIKV-NS4B-transduction on the global proteome scale at early stages of hNPC differentiation into neurons, hNPC cells were infected with ZIKV (Asian strain: H/PF/2013; MOI=0.01) or transduced with ZIKV-NS4B or HCV-NS4B and one day later cells were either left under proliferative conditions or neuronal differentiation was induced with ROCK inhibitors treatment and growth factors withdrawals. Five days later samples were harvested and processed for quantitative label-free proteomics.
Project description:The stemness of primary thyroid samples in comparison to early and late passages of organoids was characterised by whole transcriptome analysis in addition to focussed analysus of published stemness markers.
Project description:As a result of a large number of in vitro as well as in vivo experiments with rodents, brain-derived neurotrophic factor (BDNF) and its tyrosine kinase receptor TrkB are now widely appreciated to play major roles in brain function. There is also a growing appreciation that decreased BDNF signalling may be a significant component in a wide range of brain dysfunction in humans based on the discovery of mutations and polymorphisms in the corresponding genes. Human neurons generated in vitro had been shown to be responsive to TrkB phosphorylation upon treatment with BNDF, TrkB agonist ZEB85, the related factor neurotrophin-4 (NT4). In order to compare the transcriptional changes upon treatment with the three TrkB ligands RNA-seq analysis was deployed. Cultures had been treated in triplicates with BDNF, ZEB85 or NT4 for 30 minutes, 2 hours, 12 hours and 24 hours, while non treated controls were lysed at each time-point.
Project description:To understand in detail the molecular phases that occur during the differentiation of human embryonic stem cells to hepatocyte-like cells we performed an RNA-seq time course of the stages of differentiation across the 21 day differentiation time course. We used a chemically defined (serum-free) protocol, modified from Si-Tayeb et al., 2010 and Song et al., 2009. We describe acquisition of definitive endoderm characteristics at day 3, followed by hepatoblast charcter at day 7-13 and then maturation to hepatocyte-like cells at day 21. Time course of differentiation of human embryoic stem cells to hepatocyte-like cells over 21 days, using an adapted chemically defined protocol of Song et al., 2009; Cell Research
Project description:Anterior foregut endoderm (AFE) gives rise to many tissue types of interest for therapeutic research including the esophagus, salivary glands, lung, thymus, parathyroid and thyroid. Despite its importance, only few reports describe the generation of AFE from pluripotent stem cells (PSCs) by directed differentiation. Here, we describe a novel protocol to derive a subdomain of AFE, identified by expression of Pax9, from PSCs using small molecules and chemically defined conditions. Generation of a reporter PSC line allows isolation and characterization of Pax9+ AFE cells. When transplanted in vivo, Pax9+ AFE can form several distinct types of complex anterior foregut epithelia including mucosal glands and stratified squamous epithelium. Finally, we show that the directed differentiation protocol can be used to generate AFE from DiGeorge Syndrome patient-specific human induced PSCs, thus creating a platform to produce anterior foregut derivatives for therapy and to enable the study of disorders of the AFE. Total RNA obtained from FACS purified from in vitro dervied mouse definitive endoderm, anterior foregut and ES cells. AFE cells were derived from a 129X1/SvJ background, DE cells from 129X1/SvJ x 129S1/SV-+p+Tyr- cKitlSl-J/+ (R1 ES cells) and non reporter ES cells from a 129P2/OlaHsd background.
Project description:Cell state evolution underlies tumor development and response to therapy1, but mechanisms specifying cancer cell states and intratumor heterogeneity are incompletely understood. Schwannomas are the most common tumors of the peripheral nervous system and are treated with surgery and ionizing radiation2–5. Schwannomas can oscillate in size for many years after radiotherapy6,7, suggesting treatment may reprogram schwannoma cells or the tumor microenvironment. Here we show epigenetic reprogramming shapes the cellular landscape of schwannomas. We find schwannomas are comprised of 2 molecular groups distinguished by reactivation of neural crest development pathways or misactivation of nerve injury mechanisms that specify cancer cell states and the architecture of the tumor immune microenvironment. Schwannoma molecular groups can arise independently, but ionizing radiation is sufficient for epigenetic reprogramming of neural crest to immune-enriched schwannoma by remodeling chromatin accessibility, gene expression, and metabolism to drive schwannoma cell state evolution and immune cell infiltration. To define functional genomic mechanisms underlying epigenetic reprograming of schwannomas, we develop a technique for simultaneous interrogation of chromatin accessibility and gene expression coupled with genetic and therapeutic perturbations in single-nuclei. Our results elucidate a framework for understanding epigenetic drivers of cancer evolution and establish a paradigm of epigenetic reprograming of cancer in response to radiotherapy.