Prediction of Cis-Regulatory Elements Controlling Genes Differentially Expressed by Retinal and Choroidal Vascular Endothelial Cells.
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ABSTRACT:
SUBMITTER: Choi D
PROVIDER: S-EPMC2573398 | biostudies-literature |
REPOSITORIES: biostudies-literature
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Project description:Consistent with clinical observations that posterior uveitis frequently involves the retinal vasculature and recent recognition of vascular heterogeneity, we hypothesized that retinal vascular endothelium was a cell population of unique molecular phenotype. Donor-matched cultures of primary retinal and choroidal endothelial cells from 6 human cadavers were incubated with either Toxoplasma gondii tachyzoites (10:1, parasite:cell) or Escherichia coli lipopolysaccharide (100 ng/mL); control cultures were simultaneously incubated with medium. Gene expression profiling of endothelial cells was performed using oligonucleotide arrays containing probes designed to detect 8747 human transcripts. After normalization, differential gene expression was assessed by the significance analysis of microarrays, with the false discovery rate set at 5 %. For selected genes, differences in level of expression between retinal and choroidal cells were evaluated by real-time RT-PCR. Graphical descriptive analysis demonstrated strong correlation between gene expression of unstimulated retinal and choroidal endothelial cells, but also highlighted distinctly different patterns of expression that were greater than differences noted between donors or between unstimulated and stimulated cells. Overall, 779 of 8,747 transcripts (8.9 %) were differentially represented. Notably, the 330 transcripts that were present at higher levels in retinal cells included a larger percentage of transcripts encoding molecules involved in the immune response. Differential gene expression was confirmed for 12 transcripts by RT-PCR. Retinal and choroidal vascular endothelial cells display distinctive gene expression profiles. Our findings suggest the possibility of treating posterior uveitis by targeting specific interactions between the retinal endothelial cell and an infiltrating leukocyte. Experiment Overall Design: Retinal and choroidal vascular endothelial cells were isolated from both eyes of 6 human cadaver donors. Endothelial cells of each subtype from each donor were separately pooled and cultured. In a first series of experiments (Experiment 1), donor-matched cultures of retinal and choroidal endothelial cells derived from 3 donors were incubated with either T. gondii tachyzoites or medium alone. In a second set of experiments (Experiment 2), cultured retinal and choroidal endothelial cells derived from the other 3 donors were stimulated with LPS or medium alone. Whenever possible, 2 replicate dishes of endothelial cells were subjected to each set of conditions. Subsequent to incubations, mRNA was extracted from a cell lysate prepared from each dish of cells, and cRNA derived from each mRNA preparation was separately hybridized to one oligonucleotide expression array.
2008-06-15 | E-GEOD-7850 | biostudies-arrayexpress
Project description:BackgroundThe male germ line in flowering plants is initiated within developing pollen grains via asymmetric division. The smaller cell then becomes totally encased within a much larger vegetative cell, forming a unique "cell within a cell structure". The generative cell subsequently divides to give rise to two non-motile diminutive sperm cells, which take part in double fertilization and lead to the seed set. Sperm cells are difficult to investigate because of their presence within the confines of the larger vegetative cell. However, recently developed techniques for the isolation of rice sperm cells and the fully annotated rice genome sequence have allowed for the characterization of the transcriptional repertoire of sperm cells. Microarray gene expression data has identified a subset of rice genes that show unique or highly preferential expression in sperm cells. This information has led to the identification of cis-regulatory elements (CREs), which are conserved in sperm-expressed genes and are putatively associated with the control of cell-specific expression.FindingsWe aimed to identify the CREs associated with rice sperm cell-specific gene expression data using in silico prediction tools. We analyzed 1-kb upstream regions of the top 40 sperm cell co-expressed genes for over-represented conserved and novel motifs. Analysis of upstream regions with the SIGNALSCAN program with the PLACE database, MEME and the Mclip tool helped to find combinatorial sets of known transcriptional factor-binding sites along with two novel motifs putatively associated with the co-expression of sperm cell-specific genes.ConclusionsOur data shows the occurrence of novel motifs, which are putative CREs and are likely targets of transcriptional factors regulating sperm cell gene expression. These motifs can be used to design the experimental verification of regulatory elements and the identification of transcriptional factors that regulate sperm cell-specific gene expression.
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Project description:Consistent with clinical observations that posterior uveitis frequently involves the retinal vasculature and recent recognition of vascular heterogeneity, we hypothesized that retinal vascular endothelium was a cell population of unique molecular phenotype. Donor-matched cultures of primary retinal and choroidal endothelial cells from 6 human cadavers were incubated with either Toxoplasma gondii tachyzoites (10:1, parasite:cell) or Escherichia coli lipopolysaccharide (100 ng/mL); control cultures were simultaneously incubated with medium. Gene expression profiling of endothelial cells was performed using oligonucleotide arrays containing probes designed to detect 8747 human transcripts. After normalization, differential gene expression was assessed by the significance analysis of microarrays, with the false discovery rate set at 5 %. For selected genes, differences in level of expression between retinal and choroidal cells were evaluated by real-time RT-PCR. Graphical descriptive analysis demonstrated strong correlation between gene expression of unstimulated retinal and choroidal endothelial cells, but also highlighted distinctly different patterns of expression that were greater than differences noted between donors or between unstimulated and stimulated cells. Overall, 779 of 8,747 transcripts (8.9 %) were differentially represented. Notably, the 330 transcripts that were present at higher levels in retinal cells included a larger percentage of transcripts encoding molecules involved in the immune response. Differential gene expression was confirmed for 12 transcripts by RT-PCR. Retinal and choroidal vascular endothelial cells display distinctive gene expression profiles. Our findings suggest the possibility of treating posterior uveitis by targeting specific interactions between the retinal endothelial cell and an infiltrating leukocyte. Keywords: Cell type comparison, stress response
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