Previous lineage analyses have shown that retinal progenitor cells (RPCs) are multipotent throughout development, and expression profiling studies have shown a great deal of molecular heterogeneity among RPCs. To determine if the molecular heterogeneity predicts that an RPC will produce particular types of progeny, clonal lineage analysis was used to investigate the progeny of a subset of RPCs, those that express the basic helix-loop-helix (bHLH) transcription factor, Olig2. In contrast to the large and complex set of clones generated by viral marking of random embryonic RPCs, the embryonic Olig2+ RPCs underwent terminal divisions, producing small clones with primarily two of the five cell types being made by the pool of RPCs at that time. The embryonically produced cell types made by Olig2+ RPCs were cone photoreceptors and horizontal cell (HC) interneurons. Moreover, the embryonic Olig2+ RPC did not make the later Olig2+ RPC. The later, postnatal Olig2+ RPCs also made terminal divisions, which were biased towards production of rod photoreceptors and amacrine cell (AC) interneurons. These data indicate that the multipotent progenitor pool is made up of distinctive types of RPCs, which have biases towards producing subsets of retinal neurons in a terminal division, with the types of neurons produced varying over time. This strategy is similar to that of the developing Drosophila melanogaster ventral nerve cord, with the Olig2+ cells behaving as ganglion mother cells.
Transcription factor Olig2 defines subpopulations of retinal progenitor cells biased toward specific cell fates.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identification of distinct changes in gene expression after modulation of melanoma tumor antigen p97 (melanotransferrin) in multiple models in vitro and in vivo.
Cell line
View SamplesMelanoma tumor antigen p97 or melanotransferrin (MTf) is an iron (Fe)-binding protein with high homology to serum transferrin. MTf is expressed at very low levels in normal tissues and in high amounts in melanoma cells. The over-expression of MTf in tumor cells was hypothesized to assist rapidly proliferating neoplastic cells with their increased Fe requirements. However, our recent characterization of the MTf knockout (MTf -/-) mouse demonstrated that MTf did not have an essential role in Fe metabolism. To understand the function of MTf, we utilized whole-genome microarray analysis to examine the gene expression profile of five models after modulating MTf expression. These models included two new stably transfected MTf hyper-expression models (SK-N-MC neuroepithelioma and LMTK- fibroblasts) and one cell type (SK-Mel-28 melanoma) where MTf was down-regulated by post-transcriptional gene silencing. These findings were compared to alterations in gene expression identified using the MTf -/- mouse. In addition, the changes identified from the gene array data were also assessed in a new model of MTf down-regulation in SK-Mel-2 melanoma cells. In the cell line models, MTf hyper-expression led to increased cellular proliferation, while MTf down-regulation resulted in decreased proliferation. Across all five models of MTf down- and up-regulation, we identified three genes modulated by MTf expression. These included ATP-binding cassette sub-family B member 5 (Abcb5), whose change in expression mirrored MTf down- or up-regulation. In addition, thiamine triphosphatase (Thtpa) and transcription factor 4 (Tcf4) were inversely expressed relative to MTf levels across all five models. The products of these three genes are involved in membrane transport, thiamine phosphorylation and cell proliferation/survival, respectively. This study identifies novel molecular targets directly or indirectly regulated by MTf and potential pathways involved in its function. These molecular targets could be involved, at least in part, to the role of MTf in modulating proliferation.
Identification of distinct changes in gene expression after modulation of melanoma tumor antigen p97 (melanotransferrin) in multiple models in vitro and in vivo.
Cell line
View SamplesMelanoma tumor antigen p97 or melanotransferrin (MTf) is an iron (Fe)-binding protein with high homology to serum transferrin. MTf is expressed at very low levels in normal tissues and in high amounts in melanoma cells. The over-expression of MTf in tumor cells was hypothesized to assist rapidly proliferating neoplastic cells with their increased Fe requirements. However, our recent characterization of the MTf knockout (MTf -/-) mouse demonstrated that MTf did not have an essential role in Fe metabolism. To understand the function of MTf, we utilized whole-genome microarray analysis to examine the gene expression profile of five models after modulating MTf expression. These models included two new stably transfected MTf hyper-expression models (SK-N-MC neuroepithelioma and LMTK- fibroblasts) and one cell type (SK-Mel-28 melanoma) where MTf was down-regulated by post-transcriptional gene silencing. These findings were compared to alterations in gene expression identified using the MTf -/- mouse. In addition, the changes identified from the gene array data were also assessed in a new model of MTf down-regulation in SK-Mel-2 melanoma cells. In the cell line models, MTf hyper-expression led to increased cellular proliferation, while MTf down-regulation resulted in decreased proliferation. Across all five models of MTf down- and up-regulation, we identified three genes modulated by MTf expression. These included ATP-binding cassette sub-family B member 5 (Abcb5), whose change in expression mirrored MTf down- or up-regulation. In addition, thiamine triphosphatase (Thtpa) and transcription factor 4 (Tcf4) were inversely expressed relative to MTf levels across all five models. The products of these three genes are involved in membrane transport, thiamine phosphorylation and cell proliferation/survival, respectively. This study identifies novel molecular targets directly or indirectly regulated by MTf and potential pathways involved in its function. These molecular targets could be involved, at least in part, to the role of MTf in modulating proliferation.
Identification of distinct changes in gene expression after modulation of melanoma tumor antigen p97 (melanotransferrin) in multiple models in vitro and in vivo.
Cell line
View SamplesMelanoma tumor antigen p97 or melanotransferrin (MTf) is an iron (Fe)-binding protein with high homology to serum transferrin. MTf is expressed at very low levels in normal tissues and in high amounts in melanoma cells. The over-expression of MTf in tumor cells was hypothesized to assist rapidly proliferating neoplastic cells with their increased Fe requirements. However, our recent characterization of the MTf knockout (MTf -/-) mouse demonstrated that MTf did not have an essential role in Fe metabolism. To understand the function of MTf, we utilized whole-genome microarray analysis to examine the gene expression profile of five models after modulating MTf expression. These models included two new stably transfected MTf hyper-expression models (SK-N-MC neuroepithelioma and LMTK- fibroblasts) and one cell type (SK-Mel-28 melanoma) where MTf was down-regulated by post-transcriptional gene silencing. These findings were compared to alterations in gene expression identified using the MTf -/- mouse. In addition, the changes identified from the gene array data were also assessed in a new model of MTf down-regulation in SK-Mel-2 melanoma cells. In the cell line models, MTf hyper-expression led to increased cellular proliferation, while MTf down-regulation resulted in decreased proliferation. Across all five models of MTf down- and up-regulation, we identified three genes modulated by MTf expression. These included ATP-binding cassette sub-family B member 5 (Abcb5), whose change in expression mirrored MTf down- or up-regulation. In addition, thiamine triphosphatase (Thtpa) and transcription factor 4 (Tcf4) were inversely expressed relative to MTf levels across all five models. The products of these three genes are involved in membrane transport, thiamine phosphorylation and cell proliferation/survival, respectively. This study identifies novel molecular targets directly or indirectly regulated by MTf and potential pathways involved in its function. These molecular targets could be involved, at least in part, to the role of MTf in modulating proliferation.
Identification of distinct changes in gene expression after modulation of melanoma tumor antigen p97 (melanotransferrin) in multiple models in vitro and in vivo.
Cell line
View SamplesMale and female CD-1 mice were administered dietary Phenobarbital for 2 or 7 days. In-life, enzyme activity, cell proliferation, genomic analysis, and Bench-mark dose modeling was carried out.
Dose-response modeling of early molecular and cellular key events in the CAR-mediated hepatocarcinogenesis pathway.
Specimen part
View SamplesWe demonstrate diverse roles of interferongamma (IFN-) in the induction and regulation of immune-mediated inflammation using a transfer model of autoimmune diabetes. The diabetogenic CD4+BDC2.5 (BDC) T cell clone upon transfer into NOD.scid mice induced destruction of islets of Langerhans leading to diabetes. Administration of a neutralizing antibody to IFN- (H22) resulted in long term protection (LTP) from diabetes, with inflammation but persistence of a significant, albeit decreased numbers of -cells. BDC T cells were a mixture of cells expressing high, intermediate and low levels of the T cell receptor. Clonotype-low BDC T cells were required for LTP. Furthermore, islet infiltrating leukocytes in the LTP mice contained Foxp3+CD4 T cells. Islet inflammation in both diabetic and LTP mice was characterized by heavy infiltration of macrophages. Gene expression profiles indicated that macrophages in diabetic mice were M1-type, while LTP mice contained M2-differentiated. The LTP was abolished if mice were treated with either an antibody depleting CD4 T cells, or a neutralizing antibody to CTLA-4, in this case, only at a late stage. Neutralization of IL-10, TGF-, GITR or CD25 had no effect. Transfer of only clonotype-high expressing BDC T cells induced diabetes but in contrast, H22 antibodies did not inhibit diabetes. While clonotype high T cells induced diabetes even when IFN- was neutralized, paradoxically, there was reduced inflammation and no diabetes if host myeloid cells lacked IFN- receptor. Hence, using monoclonal CD4 T cells, IFN- can have a wide diversity of roles, depending on the setting of the immune process.
IFN-gamma-dependent regulatory circuits in immune inflammation highlighted in diabetes.
No sample metadata fields
View SamplesIron-deficiency affects 500 million people, yet the molecular role of iron in gene expression remains poorly characterized. Moreover, the alterations in global gene expression after iron chelation remains unclear and are important to assess for understanding the molecular pathology of iron-deficiency and the biological effects of iron chelators. We assessed the effect on whole genome gene expression of two iron chelators (desferrioxamine and 2-hydroxy-1-napthylaldehyde isonicotinoyl hydrazone) that have markedly different permeability properties. Sixteen genes were significantly regulated by both chelators, while a further 50 genes were regulated by either ligand. Most of the genes identified in this study have not been previously described to be iron-regulated and are important for understanding the molecular and cellular effects of iron-deficiency.
Iron chelator-mediated alterations in gene expression: identification of novel iron-regulated molecules that are molecular targets of hypoxia-inducible factor-1 alpha and p53.
Cell line, Time
View SamplesSeedlings of 35 different Arabidopsis thaliana ecotypes were compared. Triplicates were performed of 10 ecotpyes, single arrays of 25 ecotypes.
Diversity of flowering responses in wild Arabidopsis thaliana strains.
Specimen part
View SamplesWhole-genome gene expression analysis has been successfully utilized to diagnose, prognosticate, and identify potential therapeutic targets for cardiovascular disease. However, the utility of this approach to identify outcome-related genes and dysregulated pathways following first-time myocardial infarction (AMI) remains unknown and may offer a novel strategy to detect affected expressome networks that predict long-term outcome. Whole-genome microarray and targeted cytokine expression profiling on blood samples from normal cardiac function controls and first-time AMI patients within 48-hours post-MI revealed expected differential gene expression profiles enriched for inflammation and immune-response pathways in AMI patients. To determine molecular signatures at the time of AMI that could prognosticate long-term outcomes, transcriptional profiles from sub-groups of AMI patients with (n=5) or without (n=22) any recurrent events over an 18-month follow-up were compared. This analysis identified 559 differentially expressed genes. Bioinformatic analysis of this differential gene set for associated pathways revealed 1) increasing disease severity in AMI patients is associated with a decreased expression of the developmental epithelial-to-mesenchymal transition, and 2) modulation of cholesterol transport genes that include ABCA1, CETP, APOA1, and LDLR is associated with clinical outcome. In conclusion, differentially regulated genes and modulated pathways were identified that predicted recurrent cardiovascular outcomes in first-time AMI patients. This cell-based approach for risk stratification in AMI warrants a larger study to determine the role of metabolic remodeling and regenerative processes required for optimal outcomes. A validated transcriptome assay could represent a novel, non-invasive platform to anticipate modifiable pathways and therapeutic targets to optimize long-term outcome for AMI patients.
Transcriptome from circulating cells suggests dysregulated pathways associated with long-term recurrent events following first-time myocardial infarction.
Specimen part, Disease
View Samples