Project description:To comprehensively profile early neurodevelopmental alterations in individuals with ASD, we harnessed a time series approach to monitor patient-derived induced pluripotent stem cells (iPSCs) throughout the recapitulation of cortical development. This dataset consists of patient derived neurons that go through all consecutive developmental stages (NSC-derived neurons) as well as a comparative set of iPSC-iNs (neurons generated from the same patients that bypass early NSC-like stages using an Ngn2-transgene approach). For this, we first used fluorescence-activated cell sorting (FACS) to purify a homogeneous population of NSCs based on the expression of the cell-surface markers CD184+/CD271-/CD44-/CD24-/CD15+. To trace ASD and control neurons over time, we performed a series of retroviral lineage-tracing experiments to trace the progenies of dividing NSCs using a retroviral vector expressing a membrane-tagged enhanced green fluorescent protein (eGFP) (CAG::LckN-eGFP). As differentiating neurons express PSA-NCAM on the cell surface, we established a FACS-based protocol for purification of defined subpopulations of retrovirally labeled eGFP+/PSA-NCAM+ double-positive neurons after 2, 4, 7 and 14 days of differentiation. IPSCs were sorted based on the expression of SSEA-4 and TRA1-81 and maturing iPSC-iNs were collected at the indicated days after induction by sorting for eGFP (indicative for the Ngn2 transgene)- and PSA-NCAM-positive cells.
Project description:We have obtained fibroblast cultures from old adult human control donors and Alzheimer patients. The fibroblasts were reprogrammed into directly induced neurons (iNs) to serve as an adult-like and age-equivalent model for aging and neurodegeneration. iNs were treated for 10 days with 10 µM shikonin or DMSO.
Project description:Methylation array was used to quantify CpG methylation to determine if NC+ZPAK media was affecting the age of the donor after neuron conversion. Beta values were determined using the ChAMP methylation analysis pipeline.
Project description:All established protocols for differentiation of mouse and human pluripotent stem cells into specific neural subpopulations generate a considerable cellular heterogeneity that hampers experimental and clinical progress. In order to obtain a homogenous population of neuronal precursor cells and to streamline the differentiation of embryonic stem cells (ESCs), we assessed PSA-NCAM, a surface glycoprotein that is specifically expressed on immature neurons. We developed an optimized strategy for magnetic isolation of PSA-NCAM positive neuronal precursors from differentiated ESC cultures and characterized their neuronal differentiation potential in vitro. PSA-NCAM enrichment at an early step of neural differentiation increased the number of ES cell derived neurons and reduced cellular diversity. Gene expression analysis revealed that mainly genes involved in neuronal activity were over-represented after purification. The in vivo potential of in vitro derived PSA-NCAM+ enriched precursors was functionally characterized by grafting into the forebrain of adult mice. Analysis for several neuronal and glia markers at 10 or 40 days post graft showed a distinct differentiation pattern. While unsorted control cells gave rise to a mixed population composed of immature precursors, early postmitotic neurons or glial cells, the majority of PSA-NCAM+ enriched cells differentiated into NeuN positive neurons. Furthermore, when in contact with the rostral migratory stream, higher numbers of cells integrated into the stream and migrated towards the olfactory bulb when the PSA-NCAM enriched population was grafted. Thus, enrichment of neuronal precursors based on PSA-NCAM expression represents a general and straightforward approach to narrow cellular heterogeneity during neuronal differentiation of pluripotent cells. Two conditions (step 4, step 5), each represented by three biological replicates of control and enriched cells (Cy5); mESC was used as common reference (Cy3)
Project description:The progeny of neural stem cells in the subventricular zone (SVZ) of the adult mammalian brain consists in polysialylated NCAM-expressing immature neurons (PSA(+) cells), which migrate to the olfactory bulb (OB) to differentiate into GABAergic interneurons. We purified murine PSA(+) cells directly from the adult brain by FACS and analyzed their gene expression profile by SAGE. Comparative analyses led to the identification of precursor-enriched genes, including Survivin, Sox-4, Meis2, Dishevelled-2, C3aR1 and Riken 3110003A17, and many so far uncharacterized transcripts. Cluster analysis showed that groups of genes involved in axon guidance and gene clusters implicated in chemotaxis are strongly upregulated, indicating a role of both cues in the control of cell migration in the adult brain. Furthermore, genes involved in apoptosis and cell proliferation are co-expressed, suggesting that the amount of precursors that is present in the adult brain is a result of an equilibrium of these processes. Keywords: neuronal precursors, adult SVZ, mouse, gene expression analysis Please see Pennartz et al., Mol Cell Neurosci. 2004 Apr;25(4):692-706 and PhD thesis "Gene expression analysis of neuronal precursors from adult mouse brain and differential screen for neural stem cell markers" http://deposit.ddb.de/cgi-bin/dokserv?idn=973392754
Project description:Spinal Muscular Atrophy (SMA) is an autosomal recessive motor neuron disease and is the second most common genetic disorder leading to death in childhood. Motoneurons derived from induced pluripotent stem cells (iPSC) obtained by reprogramming SMA patient and his healthy father fibroblasts, and genetically corrected SMA-iPSC obtained converting SMN2 into SMN1 with target gene correction (TGC), were used to study gene expression and splicing events linked to pathogenetic mechanisms. Microarray technology was used to assess the global gene expression profile as well as splicing events of iPS-derived motorneurons from SMA patient, unaffected father and TGC-treated cells. The microarray data derived from three different groups: SMA patient, healty father and treated SMA patient's cells. Each population consists of three RNA profiling cell samples.
Project description:Kabuki Syndrome (KS) is a multisystemic rare disorder, characterized by growth delay, distinctive facial features, intellectual disability, and rarely autism spectrum disorder. This condition is mostly caused by de novo mutations of KMT2D, encoding a catalytic subunit of the COMPASS complex involved in enhancer regulation. KMT2D catalyzes the deposition of histone-3-lysine-4 mono-methyl (H3K4Me1) that marks active and poised enhancers. To assess the impact of KMT2D mutations in the chromatin landscape of KS tissues, we have generated patient-derived induced pluripotent stem cells (iPSC), which we further differentiated into neural crest stem cells (NCSC), mesenchymal stem cells (MSC) and cortical neurons (iN). In addition, we further collected blood samples from 5 additional KS patients. To complete our disease modeling cohort we generated an isogenic KMT2D mutant line from human embryonic stem cells, which we differentiated into neural precursor and mature neurons. Micro-electrode-array (MEA)-based neural network analysis of KS iNs revealed an altered pattern of spontaneous network-bursts in a Kabuki-specific pattern. RNA-seq profiling was performed to relate this aberrant MEA pattern to transcriptional dysregulations, revealing that dysregulated genes were enriched for neuronal functions, such as ion channels, synapse activity, and electrophysiological activity. Here we show that KMT2D haploinsufficiency tends to heavily affect the transcriptome of cortical neurons and differentiated tissues while sparing multipotent states, suggesting that KMT2D has a most prevalent role in terminally differentiated cell and activate transcriptional circuitry unique to each cell type. Moreover, thorough profiling of H3K4Me1 unveiled the almost complete uncoupling between this chromatin mark and the regulatory effects of KMT2D on transcription, which is instead reflected by a defect of H3K27Ac. By integrating RNA-seq with ChIP-seq data we defined TEAD and REST as the master effectors of KMT2D haploinsufficiency. Also, we identified a subset of genes whose regulation is controlled by the balance between KMT2D and EZH2 dosage. Finally, we identified the bona fide direct targets of KMT2D in healthy and KS mature cortical neurons and TEAD2 as the main proxy of KMT2D dysregulation in KS. Overall, our study provides the transcriptional and epigenomic characterization of patient-derived tissues as well as iPSCs and differentiated disease-relevant cell types, as well as the identification of KMT2D direct target in cortical neurons, together with the identification of a neuronal phenotype of the spontaneous electrical activity.
Project description:Bulk RNA was extracted via trizol at Fibroblasts stage, 5 days, 10 days, 15 days, and 20 days of fibroblast to neuron conversion using traditional NC media, or NC media supplemented with ZM336372, pyrintegrin, AZ960, and KC7F2
Project description:To gain insights into the interplay between DNA methylation and gene regulation we generated a basepair resolution reference map of the mouse methylome in stem cells and neurons. High genome coverage allowed for a novel quantitative analysis of local methylation states, which identified Low Methylated Regions (LMR) with an average methylation of 30%. These regions are evolutionary conserved, reside outside of CpG islands and distal to promoters. They represent regulatory regions evidenced by their DNaseI hypersensitivity and chromatin marks of enhancer elements. LMRs are occupied by transcription factors (TF) and their reduced methylation requires TF binding while introduction of TF binding sites creates LMRs de novo. This dependency on TF activity is further evident when comparing the methylomes of embryonic stem cells and derived neuronal cells. LMRs present in both cell types are occupied by broadly expressed factors, while LMRs present at only one state are occupied by cell-type specific TFs. Methylome data can thus enhance the prediction of occupied TF binding sites and identification of active regulatory regions genome-wide. Our study provides reference methylomes for the mouse at two cell states, identifies a novel and highly dynamic feature of the epigenome that defines distal regulatory elements and shows that transcription factor binding dynamically shapes mammalian methylomes. RNA_sequencing of mouse embryonic stem (ES) cells and derived neuronal progenitors (NP).