Trypanosoma cruzi is an obligate intracellular protozoan parasite that causes human Chagas disease, a leading cause of heart failure in Latin America. Using Affymetrix oligonucleotide arrays we screened phenotypically diverse human cells (foreskin fibroblasts, microvascular endothelial cells and vascular smooth muscle cells) for a common transcriptional response signature to T. cruzi. A common feature was a prominent type I interferon response, indicative of a secondary response to secreted cytokines. Using transwell plates to distinguish cytokine-dependent and -independent gene expression profiles in T. cruzi-infected cells, a core cytokine-independent response was identified in fibroblasts and endothelial cells that featured metabolic and signaling pathways involved in cell proliferation, amino acid catabolism and response to wounding. Significant downregulation of genes involved in mitotic cell cycle and cell division predicted that T. cruzi infection impedes cell cycle progression in the host cell.
Cytokine-dependent and-independent gene expression changes and cell cycle block revealed in Trypanosoma cruzi-infected host cells by comparative mRNA profiling.
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View SamplesExpression profile for undifferentiated F9 Embryonal Carcinoma cell line
Identification of active transcriptional regulatory modules by the functional assay of DNA from nucleosome-free regions.
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View SamplesMicroarray analysis was performed to identify transcriptional changes that occur during mucociliary differentiation of human primary bronchial epithelial cells cultured at an air-liquid interface (ALI).
Transcriptional profiling of mucociliary differentiation in human airway epithelial cells.
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View SamplesEpidemiology studies have linked exposure to pollutant particles to increased cardiovascular mortality and morbidity, however, the mechanism remains unknown. In this study, we hypothesized that the ultrafine fraction of ambient pollutant particles would cause endothelial cells dysfunction. We profiled gene expression of human pulmonary artery endothelial cells (HPAEC) exposed to ultrafine Chapel Hill particles (UFP) (100g/ml) or vehicle for 4h with Affymetrix HG U133 Plus 2.0 chips (N = 4 each). Using an unpaired t-test (p <0.01, 5% false discovery rate) we found 426 unique genes to be differentially expressed with 320 upregulated genes and 106 downregulated genes. Among these genes, we noted upregulation of genes related to coagulation-inflammation circuitry including tissue factor (F3), coagulation factor II receptor-like 2 (F2RL2, PAR3), interleukin (IL)-6 and IL-8. Upregulation of these genes were independently confirmed by RT-PCR and/or protein release. Genes related to the CXC chemokine family that have been implicated in the pathogenesis of vascular disease were upregulated, including MCP-1 (2.60 fold), IL-8 (2.47 fold), CXCL1 (1.41 fold), CXCL2 (1.95 fold), CXCL3 (2.28 fold) and CXCR4 (1.30 fold). In addition, genes related to clotting independent signaling of F3 were also differentially expressed, including FOS, JUN and NFKBIA. Treatment of HPAEC with UFP for 16 hours increased the release of IL6 and IL8 by 1.9-fold and 1.8-fold respectively. Pretreatment of HPAEC with a blocking antibody against F3 attenuated IL6 and IL8 release by 30% and 70% respectively. Thus using gene profiling, we uncovered that UFP may induce vascular endothelial cells to express genes related to clotting and angiogenesis. These results provide a novel hypothesis that PM may cause cardiovascular adverse health effects via induction of tissue factor in vascular endothelial cells which then triggers clotting dependent and independent downstream signaling.
Up-regulation of tissue factor in human pulmonary artery endothelial cells after ultrafine particle exposure.
Treatment
View SamplesThe roundworm Caenorhabditis elegans is a heme auxotroph that requires the coordinated actions of HRG-1 heme permeases to transport environmental heme into the intestine and HRG-3, a secreted protein, to deliver intestinal heme to other tissues including the embryo. Here we show that heme homeostasis in the extraintestinal hypodermal tissue is facilitated by the transmembrane protein HRG-2. Systemic heme deficiency upregulates hrg-2 mRNA expression over 200-fold in the main body hypodermal syncytium hyp 7. HRG-2 is a type I membrane protein which binds heme and localizes to the endoplasmic reticulum and apical plasma membrane. Cytochrome heme profiles are aberrant in HRG-2 deficient worms, a phenotype that is partially suppressed by heme supplementation. Heme-deficient yeast strain, ectopically expressing worm HRG-2, reveal significantly improved growth at submicromolar concentrations of exogenous heme. Taken together, our results implicate HRG-2 as a facilitator of heme utilization in the C. elegans hypodermis and provide a mechanism for regulation of heme homeostasis in an extraintestinal tissue.
Heme utilization in the Caenorhabditis elegans hypodermal cells is facilitated by heme-responsive gene-2.
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View SamplesWhen using cell lines to study cancer, phenotypic similarity to the original tumor is paramount. Yet, little has been done to characterize how closely Merkel cell carcinoma (MCC) cell lines model native tumors. To determine their similarity to MCC tumor samples, we characterized MCC cell lines via gene expression microarrays. Using whole transcriptome gene expression signatures and a computational bioinformatic approach, we identified significant differences between variant cell lines (UISO, MCC13, and MCC26) and fresh frozen MCC tumors. Conversely, the classic WaGa and Mkl-1 cell lines more closely represented the global transcriptome of MCC tumors. When compared to publicly available cancer lines, WaGa and Mkl-1 cells were similar to other neuroendocrine tumors, but the variant cell lines were not. WaGa and Mkl-1 cells grown as xenografts in mice had histological and immunophenotypical features consistent with MCC, while UISO xenograft tumors were atypical for MCC. Spectral karyotyping and short tandem repeat analysis of the UISO cells matched the original cell line's description, ruling out contamination. Our results validate the use of transcriptome analysis to assess the cancer cell line representativeness and indicate that UISO, MCC13, and MCC26 cell lines are not representative of MCC tumors, whereas WaGa and Mkl-1 more closely model MCC.
Assessment of cancer cell line representativeness using microarrays for Merkel cell carcinoma.
Specimen part, Disease, Cell line
View SamplesThe purpose of this study was to characterize global gene expression in human airway epithelial cells and identify cellular pathways associated with coarse, fine and ultrafine particulate matter (PM) exposures. Ambient PM was collected in 3 different size fractions from Chapel Hill air, particles were extracted from foam or filter matrices and lyophilized. Human primary airway epithelial cells were exposed to particles at 250g/ml or vehicle control for 6h in culture. Following exposure, RNA was isolated and hybridized to human HG U133A affymetrix chips.
Comparison of gene expression profiles induced by coarse, fine, and ultrafine particulate matter.
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View SamplesHuman primary keratinocytes were collected at 0, 1, 3, 6, 12, 24 and 48 hours after addition of 1.8mM Calcium and RNA was extracted.
GRHL3/GET1 and trithorax group members collaborate to activate the epidermal progenitor differentiation program.
Time
View SamplesHuman primary keratinocytes were depleted of GRHL3 by siRNA and induced to differentiated for 2 days by addition of Calcium
GRHL3/GET1 and trithorax group members collaborate to activate the epidermal progenitor differentiation program.
Specimen part, Treatment
View SamplesWe used microarrays to characterize the whole blood global gene expression profiles in 98 children with P. falciparum cerebral malaria
Activated Neutrophils Are Associated with Pediatric Cerebral Malaria Vasculopathy in Malawian Children.
Specimen part
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