Human clinical trials in type 1 diabetes (T1D) patients are underway using mesenchymal stem cells (MSC) without prior validation in a mouse model for the disease. In response to this void, we characterized bone marrow-derived murine MSC for their ability to modulate immune responses in the context of T1D, as represented in non-obese diabetic (NOD) mice. In comparison to NOD-, BALB/c-MSC express higher levels of the negative costimulatory molecule PD-L1 and promote a shift toward Th2-like responses in treated NOD mice. In addition, transfer of MSC from resistant strains (i.e. NOR or BALB/c), but not from NOD mice, conferred disease protection when administered to prediabetic NOD mice. The number of BALB/c-MSC trafficking to the pancreatic lymph nodes of NOD mice was higher than in NOD mice provided autologous NOD-MSC. Administration of BALB/c-MSC resulted in reversal of hyperglycemia in 90% of NOD mice (p=0.002). Transfer of autologous NOD-MSC imparted no such therapeutic benefit, and in fact soft tissue and visceral tumors were uniquely observed in this setting (i.e. no tumors were present with BALB/c- or NOR-MSC transfer). These data provide important preclinical data supporting the basis for further development of allogeneic MSC-based therapies for T1D and potentially, other autoimmune disorders.
Immunomodulatory function of bone marrow-derived mesenchymal stem cells in experimental autoimmune type 1 diabetes.
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View SamplesIn order to detect transcriptional differences between primitive and definitive hematopoietic stem and progenitor cells during regular development in the zebrafish embryo, gata1-GFP+/+(18 somites), lmo2-GFP+/+ (18 somites and 35 hpf)1 and cd41-GFP+/+ (35 hpf) cells from transgenic embryos were individually separated from GFP-/- cells by flow cytometry at the indicated stages. For each individual population, pools of 600 - 1500 transgenic embryos were collected. After RNA extraction, labelled cRNA was hybridized onto Affymetrix microarrays. Individual experiments were performed with 2 or 3 biological replicates.
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Age
View SamplesThe molecular mechanisms underlying erythroid-specific gene regulation remain incompletely understood. Closely spaced binding sites for GATA, NF-E2/maf and CACCC interacting transcription factors play functionally important roles in globin and other erythroid-specific gene expression. We and others recently identified the CACCC-binding transcription factor ZBP-89 as a novel GATA-1 and NF-E2/mafK interacting partner. Here, we examined the role of ZBP-89 in human globin gene regulation and erythroid maturation using a primary CD34+ cell ex vivo differentiation system. We show that ZBP-89 protein levels rise dramatically during human erythroid differentiation, and that ZBP-89 occupies key cis-regulatory elements within the globin and other erythroid gene loci. ZBP-89 binding correlates strongly with RNA Pol II occupancy, active histone marks, and high-level gene expression. ZBP-89 physically associates with the histone acetyltransferases (HATs) p300 and Gcn5/Trrap, and occupies common sites with Gcn5 within the human globin loci. Lentiviral shRNA knockdown of ZBP-89 results in reduced Gcn5 occupancy, decreased acetylated histone 3 levels, lower globin and erythroid-specific gene expression, and impaired erythroid maturation. Addition of the HDAC inhibitor valproic acid partially reverses the reduced globin gene expression. These findings reveal an activating role for ZBP-89 in human globin gene regulation and erythroid differentiation.
Role of ZBP-89 in human globin gene regulation and erythroid differentiation.
Specimen part
View SamplesTen-eleven translocation (Tet) family of DNA dioxygenases converts 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5- carboxylcytosine (5caC) through iterative oxidation reactions. While 5mC and 5hmC are relatively abundant, 5fC and 5caC are at very low levels in the mammalian genome. Thymine DNA glycosylase (TDG) and base excision repair (BER) pathways can actively remove 5fC/5caC to regenerate unmethylated cytosine, but it is unclear to what extent and at which part of the genome such active demethylation processes take place. Here, we have performed high-throughput sequencing analysis of 5mC/5hmC/5fC/5caC- enriched DNA using modification-specific antibodies and generated genome-wide distribution maps of these cytosine modifications in wild-type and Tdg-deficient mouse embryonic stem cells (ESCs). We observe that the steady state 5fC and 5caC are preferentially detected at repetitive sequences in wild-type mouse ESCs. Depletion of TDG causes marked accumulation of 5fC and 5caC at a large number of distal gene regulatory elements and transcriptionally repressed/poised gene promoters, suggesting that Tet/TDG-dependent dynamic cycling of 5mC oxidation states may be involved in regulating the function of these regions. Thus, comprehensive mapping of 5mC oxidation and BER pathway activity in the mammalian genome provides a promising approach for better understanding of biological roles of DNA methylation and demethylation dynamics in development and diseases.
Genome-wide analysis reveals TET- and TDG-dependent 5-methylcytosine oxidation dynamics.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Kdm2b maintains murine embryonic stem cell status by recruiting PRC1 complex to CpG islands of developmental genes.
Specimen part, Cell line
View SamplesTen-eleven translocation (Tet) family of DNA dioxygenases converts 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5- carboxylcytosine (5caC) through iterative oxidation reactions. While 5mC and 5hmC are relatively abundant, 5fC and 5caC are at very low levels in the mammalian genome. Thymine DNA glycosylase (TDG) and base excision repair (BER) pathways can actively remove 5fC/5caC to regenerate unmethylated cytosine, but it is unclear to what extent and at which part of the genome such active demethylation processes take place. Here, we have performed high-throughput sequencing analysis of 5mC/5hmC/5fC/5caC- enriched DNA using modification-specific antibodies and generated genome-wide distribution maps of these cytosine modifications in wild-type and Tdg-deficient mouse embryonic stem cells (ESCs). We observe that the steady state 5fC and 5caC are preferentially detected at repetitive sequences in wild-type mouse ESCs. Depletion of TDG causes marked accumulation of 5fC and 5caC at a large number of distal gene regulatory elements and transcriptionally repressed/poised gene promoters, suggesting that Tet/TDG-dependent dynamic cycling of 5mC oxidation states may be involved in regulating the function of these regions. Thus, comprehensive mapping of 5mC oxidation and BER pathway activity in the mammalian genome provides a promising approach for better understanding of biological roles of DNA methylation and demethylation dynamics in development and diseases.
Genome-wide analysis reveals TET- and TDG-dependent 5-methylcytosine oxidation dynamics.
Specimen part
View SamplesPolycomb group (PcG) proteins play important roles in repressing lineage-specific genes and maintaining the undifferentiated state of mouse embryonic stem cells (mESCs). However, the mechanisms by which PcG proteins are recruited to their targets are largely unknown. Here, we show that the histone demethylase Kdm2b is highly expressed in mESCs and regulated by the pluripotent factors Oct4/Sox2 directly. Depletion of Kdm2b in mESCs causes de-repression of lineage-specific genes and induces early differentiation. The function of Kdm2b depends on its CXXC-ZF domain, which mediates Kdm2bs genome-wide binding to CpG islands (CGIs). Kdm2b interacts with the core components of the Polycomb repressive complex 1 (PRC1) and recruits the complex to the CGIs of early lineage-specific genes. Thus, our study not only reveals a novel Oct4/Sox2-Kdm2b-PRC1-CGI regulatory axis and its function in maintaining undifferentiated state of mESCs, but also demonstrates a critical function of Kdm2b in recruiting PRC1 to the CGIs of lineage-specific genes to repress their expression.
Kdm2b maintains murine embryonic stem cell status by recruiting PRC1 complex to CpG islands of developmental genes.
Specimen part, Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Activity-dependent regulation of inhibitory synapse development by Npas4.
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View Sampleswe performed a DNA microarray experiment to identify activity-regulated genes that are misregulated in the absence of Npas4.
Activity-dependent regulation of inhibitory synapse development by Npas4.
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View Sampleswe used DNA microarray analysis to identify genes that are induced by neuronal activity in excitatory neurons at the time when inhibitory synapses are forming and maturing on them.
Activity-dependent regulation of inhibitory synapse development by Npas4.
No sample metadata fields
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