ABSTRACT: Neural stem cells can migrate towards tumors of both neural and non-neural origins, which is crucial for the success in treating disseminated tumors. Although the understanding of the molecular mechanisms underlying NSC tumor tropism is limited, it has been noted that several cytokines, growth factors and receptors direct the migration in vitro. A proper understanding of the basic molecular mechanisms of NSC migration towards tumors, especially identification of key cellular regulators of the migration, will have important implications in improving the effectiveness of engineering and employing NSCs as tumor therapy agents. We compared gene expression profiles between migratory and non-migratory hiPSC-NSCs towards cancer cells using cDNA microarray profiling. We collected human iPSCs derived NSCs migrating and not migrating towards human U87 glioma cells in an in vitro migration system for total RNA extraction and hybridization to Affymetrix microarrays
Project description:Neural stem cells can migrate towards tumors of both neural and non-neural origins, which is crucial for the success in treating disseminated tumors. Although the understanding of the molecular mechanisms underlying NSC tumor tropism is limited, it has been noted that several cytokines, growth factors and receptors direct the migration in vitro. A proper understanding of the basic molecular mechanisms of NSC migration towards tumors, especially identification of key cellular regulators of the migration, will have important implications in improving the effectiveness of engineering and employing NSCs as tumor therapy agents. We compared gene expression profiles between migratory and non-migratory hiPSC-NSCs towards cancer cells using cDNA microarray profiling. We collected human iPSCs derived NSCs migrating and not migrating towards mouse 4T1 breast cancer cells in an in vitro migration system for total RNA extraction and hybridization to Affymetrix microarrays
Project description:Neural stem cells can migrate towards tumors of both neural and non-neural origins, which is crucial for the success in treating disseminated tumors. Although the understanding of the molecular mechanisms underlying NSC tumor tropism is limited, it has been noted that several cytokines, growth factors and receptors direct the migration in vitro. A proper understanding of the basic molecular mechanisms of NSC migration towards tumors, especially identification of key cellular regulators of the migration, will have important implications in improving the effectiveness of engineering and employing NSCs as tumor therapy agents. We compared gene expression profiles between migratory and non-migratory hiPSC-NSCs towards cancer cells using cDNA microarray profiling.
Project description:Neural stem cells can migrate towards tumors of both neural and non-neural origins, which is crucial for the success in treating disseminated tumors. Although the understanding of the molecular mechanisms underlying NSC tumor tropism is limited, it has been noted that several cytokines, growth factors and receptors direct the migration in vitro. A proper understanding of the basic molecular mechanisms of NSC migration towards tumors, especially identification of key cellular regulators of the migration, will have important implications in improving the effectiveness of engineering and employing NSCs as tumor therapy agents. We compared gene expression profiles between migratory and non-migratory hiPSC-NSCs towards cancer cells using cDNA microarray profiling.
Project description:BACKGROUND: The polycomb group protein Ezh2 is an epigenetic repressor of transcription originally found to prevent untimely differentiation of pluripotent embryonic stem cells. We previously demonstrated that Ezh2 is also expressed in multipotent neural stem cells (NSCs). We showed that Ezh2 expression is downregulated during NSC differentiation into astrocytes or neurons. However, high levels of Ezh2 remained present in differentiating oligodendrocytes until myelinating. This study aimed to elucidate the target genes of Ezh2 in NSCs and in premyelinating oligodendrocytes (pOLs). METHODOLOGY/PRINCIPAL FINDINGS: We performed chromatin immunoprecipitation followed by high-throughput sequencing to detect the target genes of Ezh2 in NSCs and pOLs. We found 1532 target genes of Ezh2 in NSCs. During NSC differentiation, the occupancy of these genes by Ezh2 was alleviated. However, when the NSCs differentiated into oligodendrocytes, 393 of these genes remained targets of Ezh2. Analysis of the target genes indicated that the repressive activity of Ezh2 in NSCs concerns genes involved in stem cell maintenance, in cell cycle control and in preventing neural differentiation. Among the genes in pOLs that were still repressed by Ezh2 were most prominently those associated with neuronal and astrocytic committed cell lineages. Suppression of Ezh2 activity in NSCs caused loss of stem cell characteristics, blocked their proliferation and ultimately induced apoptosis. Suppression of Ezh2 activity in pOLs resulted in derangement of the oligodendrocytic phenotype, due to re-expression of neuronal and astrocytic genes, and ultimately in apoptosis. CONCLUSIONS/SIGNIFICANCE: Our data indicate that the epigenetic repressor Ezh2 in NSCs is crucial for proliferative activity and maintenance of neural stemness. During differentiation towards oligodendrocytes, Ezh2 repression continues particularly to suppress other neural fate choices. Ezh2 is completely downregulated during differentiation towards neurons and astrocytes allowing transcription of these differentiation programs. The specific fate choice towards astrocytes or neurons is apparently controlled by epigenetic regulators other than Ezh2. Examination of Ezh2 target sites in 2 different primary cells types
Project description:A cardinal property of neural stem cells (NSCs) is their ability to adopt multiple fates upon differentiation. The epigenome is widely seen as a read-out of cellular potential and a manifestation of this can be seen in embryonic stem cells (ESCs), where promoters of many lineage-specific regulators are marked by a bivalent epigenetic signature comprising trimethylation of both lysine 4 and lysine 27 of histone H3 (H3K4me3 and H3K27me3, respectively). Bivalency has subsequently emerged as a powerful epigenetic indicator of stem cell potential. Here, we have interrogated the epigenome during differentiation of ESC-derived NSCs to immature GABAergic interneurons. We show that developmental transitions are accompanied by loss of bivalency at many promoters in line with their increasing developmental restriction from pluripotent ESC through multipotent NSC to committed GABAergic interneuron. At the NSC stage, the promoters of genes encoding many transcriptional regulators required for differentiation of multiple neuronal subtypes and neural crest appear to be bivalent, consistent with the broad developmental potential of NSCs. Upon differentiation to GABAergic neurons, all non-GABAergic promoters resolve to H3K27me3 monovalency, whereas GABAergic promoters resolve to H3K4me3 monovalency or retain bivalency. Importantly, many of these epigenetic changes occur prior to any corresponding changes in gene expression. Intriguingly, another group of gene promoters gain bivalency as NSCs differentiate toward neurons, the majority of which are associated with functions connected with maturation and establishment and maintenance of connectivity. These data show that bivalency provides a dynamic epigenetic signature of developmental potential in both NSCs and in early neurons. Neural stem cells derived from mouse embryonic stem cells were differentiated into neurons and FACS purified based on RedStar fluorescence driven by the Tau promoter. Chromatin was prepared from NSCs and neurons (n=1), sonicated to roughly 300bp and immunoprecipitated with antibodies against H3K4me3, H3K27me3, total Histone H3 and total IgG, alongside a 5% input sample. K4/K27 and corresponding input samples were analysed by ChIPSeq
Project description:Pluripotency can be induced in murine and human fibroblast by transduction of four transcription factors (Oct4, Sox2, Klf4 and c-Myc). Previously we reported that two factors (Oct4 and Klf4) are sufficient for reprogramming adult mouse neural stem cells (NSCs) to a pluripotent state. However, although NSCs endogenously express the factors Sox2, c-Myc, and Klf4, our previous report does not elucidate why exogenous expression of either Klf4 or c-Myc is still required for reprogramming. Here we report that exogenous expression of Oct4 is sufficient to generate one-factor induced pluripotent stem (1F iPS) cells without any oncogenic factors, such as c-Myc and Klf4, from mouse adult NSCs, which endogenously express Sox2, c-Myc, and Klf4, and also intermediate reprogramming markers alkaline phosphatase (AP), stage-specific embryonic antigen-1 (SSEA-1). These results extend our previous report proposing that somatic cells can be reprogrammed to a pluripotent state with a reducing number of reprogramming factors when the complementing factors are endogenously expressed in the somatic cells. Experiment Overall Design: 10 hybridizations in total. Experiment Overall Design: NSC-derived iPS cells by one-factor (Oct4) in triplicate: Experiment Overall Design: - NSC_1F_iPS_1 Experiment Overall Design: - NSC_1F_iPS_2 Experiment Overall Design: - NSC_1F_iPS_3 Experiment Overall Design: One-factor (Oct4) iPS cell-derived NSC in triplicate: Experiment Overall Design: - 1F_iPS_NSC_1 Experiment Overall Design: - 1F_iPS_NSC_2 Experiment Overall Design: - 1F_iPS_NSC_3 Experiment Overall Design: Neural stem cell (NSC) derived from brain of OG2/Rosa26 mice: Experiment Overall Design: - NSC_1 Experiment Overall Design: - NSC_2 Experiment Overall Design: - NSC_3 Experiment Overall Design: - NSC_4
Project description:miRNA profiling of human H9-derived neural stem cells (H9-NSCs) comparing control human adult dermal fibroblasts (hDFs), SOX2-transduced human induced neural stem cells (hDF-iNSC (SOX2)), SOX2/HMGA2-transduced human induced neural stem cells (hDF-iNSC (SOX2/HMGA2)). Goal was to determine the global miRNA expression between the groups. H9-NSC vs hDF vs hDF-iNSC(SOX2) vs hDF-iNSC(SOX2/HMGA2)
Project description:A cardinal property of neural stem cells (NSCs) is their ability to adopt multiple fates upon differentiation. The epigenome is widely seen as a read-out of cellular potential and a manifestation of this can be seen in embryonic stem cells (ESCs), where promoters of many lineage-specific regulators are marked by a bivalent epigenetic signature comprising trimethylation of both lysine 4 and lysine 27 of histone H3 (H3K4me3 and H3K27me3, respectively). Bivalency has subsequently emerged as a powerful epigenetic indicator of stem cell potential. Here, we have interrogated the epigenome during differentiation of ESC-derived NSCs to immature GABAergic interneurons. We show that developmental transitions are accompanied by loss of bivalency at many promoters in line with their increasing developmental restriction from pluripotent ESC through multipotent NSC to committed GABAergic interneuron. At the NSC stage, the promoters of genes encoding many transcriptional regulators required for differentiation of multiple neuronal subtypes and neural crest appear to be bivalent, consistent with the broad developmental potential of NSCs. Upon differentiation to GABAergic neurons, all non-GABAergic promoters resolve to H3K27me3 monovalency, whereas GABAergic promoters resolve to H3K4me3 monovalency or retain bivalency. Importantly, many of these epigenetic changes occur prior to any corresponding changes in gene expression. Intriguingly, another group of gene promoters gain bivalency as NSCs differentiate toward neurons, the majority of which are associated with functions connected with maturation and establishment and maintenance of connectivity. These data show that bivalency provides a dynamic epigenetic signature of developmental potential in both NSCs and in early neurons. Illumina Expresson BeadChip arrays (MouseRef-8v2.0) were used to assess gene expression changes in neural stem cells (n=5; derived from mouse embryonic stem cells) and their differentiated neuronal progeny (n=3; FACS-purified based on Tau-RedStar expression).
Project description:Throughout postnatal life in mammals, neural stem cells (NSCs) are located in the subventricular zone (SVZ) of the lateral ventricles. The greatest diversity of neuronal and glial lineages they generate occurs during early postnatal life in a region-specific manner. In order to evaluate potential heterogeneity in the NSC pool, we microdissected the dorsal and lateral SVZ at different postnatal ages and isolated NSCs and their immediate progeny based on their expression of Hes5-EGFP/Prominin1 and Ascl1-EGFP, respectively. Whole genome comparative transcriptome analysis revealed transcriptional regulators as major hallmarks that sustain postnatal SVZ regionalization. Manipulation of single genes encoding for locally enriched transcription factors influenced NSC specification indicating that the fate of regionalized postnatal SVZ NSCs can be readily modified . These findings reveal functional heterogeneity of NSCs in the postnatal SVZ and provide targets to recruit region-specific lineages in regenerative contexts. Microarrays of neural stem cells, early progenitors and the tissue from subregions of the subventricular zone were compiled to screen for the full extent of heterogeneity in this region during postnatal life. Spatially distinct regions of the developing forebrain subventricular zone (SVZ) aged at P4, P8 and P11 were microdissected in RNAse free/sterile conditions. Mice expressing Ascl1-EGFP in the SVZ were used to aid accurate microdissection of the dorsal and lateral wall of each of the studied time points as per our previous publications characterizing this method. As well as at the whole microdomain level, additionally, NSCs (Hes5-EGFP+/Prom1+) and early progenitors (Ascl1-EGFP+) from each microdomain were further isolated by FAC sorting methods. This was to provide a comprehensive gene expression analysis at the tissue level and at the cellular level. Generally, 1 litter was used to yield 1 'n' number of replicates. A total of 23 affymetrix analysis were performed.