Development of patient-specific neurons in schizophrenia using induced pluripotent stem cells: proof of principle and preliminary findings
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ABSTRACT: Induced pluripotent stem cell (iPSC) technology has the potential to address the inaccessibility of the human brain by providing investigators with patient-specific neurons that can potentially be used to carry out molecular, electrophysiological and pharmacological studies {{855 Takahashi,K. 2006}}. Although iPSC technology was primarily conceived and developed as a means to bypass the use of human embryonic stem cells (hESCs) for regenerative medicine, its potential for disease modeling may prove to be equally valuable, especially for neuropsychiatric disorders. A total of 1207 genes were found to be differentially expressed using LIMMA (>2-fold, p-value <0.05), and these genes were hierarchically clustered to form 5 groups based on their expression in day 0, 10 and 32. These were subjected to bioinformatics analysis by Gene Ontogoly (GO) and Ingenuity Pathway Analysis (IPA) to determine enrichment profiles and associated disease processes. The largest cluster (cluster III), which showed increasing expression in both day 10 and day 32 neurons, was found to be enriched with genes involved in a number of neuronal pathways including neurogenesis, neuronal differentiation, axon guidance and adhesion, among others. At a p-value of 0.05, we detected 645 and 383 genes up- and down-regulated between day 0 and day 10, respectively, and 146 and 280 genes up- and down-regulated between day 10 and day 32. In total, 1207 genes were found to be differentially expressed using LIMMA, and these genes were hierarchically clustered to form 5 groups.
Project description:Induced pluripotent stem cell (iPSC) technology has the potential to address the inaccessibility of the human brain by providing investigators with patient-specific neurons that can potentially be used to carry out molecular, electrophysiological and pharmacological studies {{855 Takahashi,K. 2006}}. Although iPSC technology was primarily conceived and developed as a means to bypass the use of human embryonic stem cells (hESCs) for regenerative medicine, its potential for disease modeling may prove to be equally valuable, especially for neuropsychiatric disorders. A total of 1207 genes were found to be differentially expressed using LIMMA (>2-fold, p-value <0.05), and these genes were hierarchically clustered to form 5 groups based on their expression in day 0, 10 and 32. These were subjected to bioinformatics analysis by Gene Ontogoly (GO) and Ingenuity Pathway Analysis (IPA) to determine enrichment profiles and associated disease processes. The largest cluster (cluster III), which showed increasing expression in both day 10 and day 32 neurons, was found to be enriched with genes involved in a number of neuronal pathways including neurogenesis, neuronal differentiation, axon guidance and adhesion, among others.
Project description:Metabolic reprogramming is a hallmark of the immune cells in response to inflammatory stimuli. This metabolic process involves a switch from oxidative phosphorylation (OXPHOS)to glycolysis, or alterations in other metabolic pathways. However, most of the experimental findings have been acquired in murine immune cells and little is known about the metabolic reprogramming of human microglia. In this study, we investigated the transcriptomic and metabolic profiles of mouse and iPSC-derived human microglia challenged with the TLR4 agonist LPS. We found that both species displayed a metabolic shift and an overall increased glycolytic gene signature in response to LPS treatment. The metabolic reprogramming was characterized by the upregulation of hexokinases in mouse microglia and phosphofructokinases in human microglia. This study provides the first direct comparison of energy metabolism between mouse and human microglia, highlighting the species-specific pathways involved in immunometabolism and the importance of considering these differences in translational research.
Project description:Induced overexpression of Pdx1 in activin-induced endoderm population resulted in the upregulation of pancreas-related genes such as insulin 1 and 2 at day 20. To enhance the developmental progression from the pancreatic bud to the formation of the endocrine lineages, we next expressed neurogenin3 (Ngn3) together with Pdx-1. Induced overexpression of Pdx1 together with Ngn3 dramatically increased Insulin 1 mRNA by day 9 differentiation. The levels of insulin 1 mRNA present in the induced EBs represented approximately 100 % of that found in insulinoma cell line, betaTC6. We also confirmed insulin and C-peptide staining by immunohistochemistry. These cells process and secrete insulin and respond to various insulin secretagogues. These inductive effects were restricted to c-kit+ endoderm enriched EB-derived populations suggesting that Pdx1/Ngn3 functions at the level of pancreatic specification of endoderm in this model. Microarray analysis showed that Pdx1/Ngn3 regulated the expression of a broad spectrum of pancreatic endocrine cell-related genes. On day 4 of a multiday differentiation protocol, EBs were dissociated and cultured in serum-free growth medium supplemented with differentiation facots, with or without Dox (1 ug/ml). On day 6, EBs were replated on gelatin in 12-well low-cluster dishes (Nunc) to obtain non-adherent floating EBs with or without Dox (1 ug/ml) and cultured out to day 13, at which time RNA was harvested for microarray analysis.
Project description:The gene targeted NKX2.1GFP/w hESC line was differentiated as spin EBs in BPEL medium supplemented with FGF2 (50-100 ng/ml). At day 7 of the differentiation, the spin EBs were pulsed with all-trans retinoic acid (10-5 M) for 72 hours. At day 10, spin EBs were removed from retinoic acid containing media and transferred from suspension to adherent culture in BEL medium containing no growth factors. Day 23 EBs were FACS sorted based on E-CADHERIN and NKX2.1-GFP expression. Day 0 hESCs, day 7 EBs, day 10 EBs with or without RA treatment and day 23 unsorted EBs and sorted fractions were subjected to Illumina microarray processing.
Project description:To isolate photoreceptor precursors fit for transplantation, we adapted a 3D differentiation protocol that generates neuroretina from mouse ES cells. We used an adeno-associated viral vector (pseudotype2/9)carrying a GFP reporter under the control of a Rhodopsin promoter (AAV2/9.Rhop.GFP)to select rod precursors. AAV2/9.Rhop.GFP+ rods were sorted at days 26 and 34 and post natal day P12.
Project description:Eed (embryonic ectoderm development) is a core component of the Polycomb Repressive Complex 2 (PRC2) which catalyzes the methylation of histone H3 lysine 27 (H3K27). Trimethylated H3K27 (H3K27me3) can act as a signal for PRC1 recruitment in the process of gene silencing and chromatin condensation. Previous studies with Eed KO ESCs revealed a failure to down-regulate a limited list of pluripotency factors in differentiating ESCs. Our aim was to analyze the consequences of Eed KO for ESC differentiation. To this end we first analyzed ESC differentiation in the absence of Eed and employed in silico data to assess pluripotency gene expression and H3K27me3 patterns. We linked these data to expression analyses of wildtype and Eed KO ESCs. We observed that in wildtype ESCs a subset of pluripotency genes including Oct4, Nanog, Sox2 and Oct4 target genes progressively gain H3K27me3 during differentiation. These genes remain expressed in differentiating Eed KO ESCs. This suggests that the deregulation of a limited set of pluripotency factors impedes ESC differentiation. Global analyses of H3K27me3 and Oct4 ChIP-seq data indicate that in ESCs the binding of Oct4 to promoter regions is not a general predictor for PRC2-mediated silencing during differentiation. However, motif analyses suggest a binding of Oct4 together with Sox2 and Nanog at promoters of genes that are PRC2-dependently silenced during differentiation. In summary, our data further characterize Eed function in ESCs by showing that Eed/PRC2 is essential for the onset of ESC differentiation. RNAs obtained from undifferentiated (d0) wild type and Eed KO ESCs and from day 3 (d3) and day 7 (d7) respective Ebs were subjected to Affymetrix Mouse Gene 1.0 ST Array. 24 samples in total.
Project description:In embryo, few Endothelial cells from Aorta would be producing Haemogenic endothelium (HE) cells. These HE cells would then be progressing to take kind of a round shape and Undergo EHT. They then take a full round shape to make Intra-aortic haematopoietic clusters (IAHC) cells. These IAHC cells would then diassociate and turn into Hematopoitic Stem Cells (HSC) that ultimately would go to produce different lineage of hematopoitic (blood) cells. We wanted to study the heterogeneity of HE in human pluripotent stem cells.
Project description:In this study we have compared functional and molecular properties of highly purified murine induced pluripotent stem (iPS) cell- and embryonic stem (ES) cell-derived cardiomyocytes (CM). In order to obtain large amounts of purified CM, we have generated a transgenic murine iPS cell line, which expresses puromycin resistance protein N-acetyltransferase and EGFP under the control of the cardiomyocyte-specific α-myosin heavy chain promoter (alphaMHC-Puro-IRES-GFP, aPiG). We demonstrate that murine aPIG-iPS and aPIG-ES cells differentiate into spontaneously beating CM at comparable efficiencies. When selected with puromycin both cell types yielded more than 97% pure population of CMs. Both aPIG-iPS and aPIG-ES cell-derived CM express typical cardiac transcripts and structural proteins and possess similar sarcomeric organization. Action potential recordings revealed that iPS- and ES cell-derived CM respond to beta-adrenergic and muscarinic receptor modulation, express functional voltage-gated sodium, calcium and potassium channels and possess comparable current densities. Comparison of global gene expression profiles of CM generated from iPS and ES cells revealed that both cell types cluster close to each other but are highly distant to undifferentiated ES or iPS cells as well as unpurified iPS and ES cell-derived embryoid bodies (EB). Both iPS and ES cell-derived CMs express genes and functional categories typical for CM. They are enriched in genes involved in transcription and genes coding for structural proteins involved in cardiac muscle contraction and relaxation. They also express genes involved in heart and muscle developmental processes, ion export and ion binding processes and various metabolic processes for ATP synthesis. These CMs downregulate genes involved in immune response, cell cycle and cell division, thus demonstrating the CMs population is mitotically inactive. Most surface signaling pathways are also downregulated. Thus, a transgenic aPiG-iPS cell line can provide a robust supply of highly purified and functional CMs for future in vitro and in vivo studies. Seven different experimental groups were included into analysis: undifferentiated murine ES cells (1) and undifferentiated murine iPS cells (2), murine ES cell-derived embyroid bodies (3) and murine iPS cell-derived embryoid bodies at day 16 of differentiation (4), murine ES cell-derived cardiomyocytes (5) and murine iPS cell-derived cardiomyocytes (6) at day 16 of differentiation (they were generated by puromycin selection for 7 days prior to RNA isolation). Adult mouse tail tip fibroblasts (7) were used as a control for iPS cells. Total RNA samples were prepared from three independent biological replicates in groups 1-6. In group 7, single RNA probes were analyzed as three technical replicates.
Project description:The aim of this study was to establish a deeply sequenced transcriptome at multiple timepoints during the differentiation of human epidermal keratinocytes from the progenitor state (d0). These transcriptomes were then assembled in order to discover novel genes and transcriptional events that are dynamically regulated during terminal differentiation of a human somatic tissue. Paired-end RNA sequencing was performed on primary human keratinocytes at three timepoints during calcium-induced epidermal differentiation.
Project description:We compared transcriptional profile of organoids derived from iPS lines of a Huntington patient (Q109) and CTR (Q21) at day 45 and day 105 of differentiation.