Down syndrome is the most common form of genetic mental retardation. How Trisomy 21 causes mental retardation remains unclear and its effects on adult neurogenesis have not been addressed. To gain insight into the mechanisms causing mental retardation we used microarrays to investigate gene expression differences between Ts1Cje (a mouse model of Down syndrome) and C57BL/6 littermate control neurospheres. The neurospheres were generated from neural stem cells and progenitors isolated from the lateral walls of the lateral ventricles from adult mice.
Gene network disruptions and neurogenesis defects in the adult Ts1Cje mouse model of Down syndrome.
Sex, Disease
View SamplesOur study in zebrafish is the first to use an animal model to understand the biology of the developmental disorder Roberts Syndrome (RBS). RBS is caused by mutations in the ESCO2 gene.
A zebrafish model of Roberts syndrome reveals that Esco2 depletion interferes with development by disrupting the cell cycle.
Age, Specimen part
View SamplesNoroviruses have been widely recognized for their importance as causative agents of non-bacterial gastroenteritis. Mouse norovirus is the only representative of the norovirus genus, family Caliciviridae, able to grow in cell culture. The aim of this study is to describe the differences in the expression profiles of MNV-1 and mock-infected macrophages (RAW 264.7 cells), in order to better understand the response of the host cell to norovirus infection.
Apoptosis in murine norovirus-infected RAW264.7 cells is associated with downregulation of survivin.
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View SamplesIn a transgenic mouse model of Alzheimer disease (AD), cleavage of the amyloid precursor protein (APP) by the -secretase ADAM10 prevented amyloid plaque formation and alleviated cognitive deficits. Furthermore, there was a positive influence of ADAM10 over-expression on neurotransmitter-specific formation of synapses and on synaptic plasticity.
Differential gene expression in ADAM10 and mutant ADAM10 transgenic mice.
Sex, Age
View SamplesLevels of C/EBP are low in myeloid blast crisis (BC) of chronic myelogenous leukemia (CML) and its expression in p210BCR/ABL-expressing hematopoietic cells induces granulocytic differentiation, inhibits proliferation and suppresses leukemogenesis. To assess the mechanisms involved in these effects, C/EBP targets were identified by microarray analyses. Upon C/EBP activation, expression of c-Myb and GATA-2 was repressed in 32D-BCR/ABL, K562 and CML-BC primary cells but only c-Myb levels decreased slightly in CD34+ normal progenitors. The role of these two genes for the biological effects of C/EBP was assessed by perturbing their expression in K562 cells. Expression of c-Myb blocked the proliferation inhibition and differentiation-inducing effects of C/EBP while c-Myb siRNA treatment enhanced C/EBP-mediated proliferation inhibition and induced changes in gene expression indicative of monocytic differentiation. GATA-2 expression suppressed the proliferation inhibitory effect of C/EBP but blocked in part the effect on differentiation; GATA-2 siRNA treatment had no effects on C/EBP induction of differentiation but inhibited proliferation of K562 cells, alone or upon C/EBP activation. In summary, the effects of C/EBP in p210BCR/ABL -expressing cells depend, in part, on transcriptional repression of c-Myb and GATA-2. Since perturbation of c-Myb and GATA-2 expression has non identical consequences for proliferation and differentiation of K562 cells, the effects of C/EBP appear to involve different transcription-regulated targets.
Transcriptional repression of c-Myb and GATA-2 is involved in the biologic effects of C/EBPalpha in p210BCR/ABL-expressing cells.
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View SamplesGenomic, proteomic, and metabolomic technologies continue to receive increasing interest from environmental toxicologists. This interest is due to the great potential of these technologies to identify detailed modes of action and to provide assistance in the evaluation of a contaminant’s risk to aquatic organisms. Our experimental model is the zebrafish (Danio rerio) exposed to reference endocrine disrupting compounds in order to investigate compound-induced changes in gene transcript profiles. Adult, female zebrafish were exposed to 0, 15, 40, and 100 ng/L of 17 alpha-ethynylestradiol (EE2) and concentration and time-dependent changes in hepatic gene expression were examined using Affymetrix GeneChip® Zebrafish Genome Microarrays. At 24, 48, and 168 hours, fish were sacrificed and liver mRNA was extracted for gene expression analysis (24 and 168 hours only). In an effort to link gene expression changes to effects on higher levels of biological organization, body and ovary weights were measured and blood was collected for measurement of plasma steroid hormones (17 beta-estradiol (E2), testosterone (T)) and vitellogenin (VTG) using ELISA. EE2 exposure significantly affected GSI, E2, T, VTG and gene expression. We observed 1575 genes that were significantly affected (up- or down-regulated by at least 1.5-fold (p ? 0.001) in a concentration-dependent manner by EE2 exposure at either 24 or 168 hours. EE2 exposure altered transcription of genes involved in steroid hormone homeostasis, cholesterol homeostasis, retinoic acid metabolism, and cell growth and proliferation. Plasma VTG was significantly increased at 24, 48, and 168 hours (p<0.05) at 40 and 100 ng/L and at 15 ng/L at 168 hours. E2 and T were significantly reduced following EE2 exposure at 48 and 168 hours. GSI was decreased in a dose-dependent manner at 168 hours. In this study, we identified genes involved in a variety of biological functions that have the potential to be used as markers of exposure to estrogenic substances. Future work will evaluate the use of these genes in zebrafish exposed to weak estrogens to determine if these genes are indicative of exposure to estrogens with varying potencies.
Hepatic gene expression profiling using Genechips in zebrafish exposed to 17alpha-ethynylestradiol.
Sex, Specimen part, Compound, Time
View SamplesThe -amyloid precursor protein APP and the related APLPs, undergo complex proteolytic processing giving rise to several fragments. Whereas it is well established that A accumulation is a central trigger for Alzheimer disease (AD), the physiological role of APP family members and their diverse proteolytic products is still largely unknown. The secreted APPs ectodomain has been shown to be involved in neuroprotection and synaptic plasticity. The -secretase generated APP intracellular domain AICD, functions as a transciptional regulator in heterologous reporter assays, although its role for endogenous gene regulation has remained controversial. To gain further insight into the molecular changes associated with knockout phenotypes and to elucidate the physiological functions of APP family members including their proposed role as transcriptional regulators we performed a DNA microarray transcriptome profiling of the frontal cortex of adult wild type, APP-/-, APLP2-/- and APPs knockin (KI) mice, APP/, expressing solely the secreted APPs ectodomain. Biological pathways affected by the lack of APP family members included regulation of neurogenesis, regulation of transcription and regulation of neuron projection development. Comparative analysis of transcriptome changes and qPCR validation identified co-regulated gene sets. Interestingly, these included heat shock proteins and plasticity related genes that were down-regulated in knock-out cortices. In contrast, we failed to detect significant differences in expression of previously proposed AICD target genes including Bace1, Kai1, Gsk3b, p53, Tip60 and Vglut2. Only Egfr was slightly up-regulated in APLP2-/- mice. Comparison of APP-/- and APP/ with wild-type mice revealed a high proportion of co-regulated genes indicating an important role of the C-terminus for cellular signaling. Finally, comparison of APLP2-/- on different genetic backgrounds revealed that background related transcriptome changes may dominate over changes due to the knockout of a single gene. Shared transcriptome profiles corroborated closely related physiological functions of APP family members in the adult central nervous system. As expression of proposed AICD target genes was not altered in adult cortex, this may indicate that these genes are not affected by lack of APP under resting conditions or only in a small subset of cells.
Comparative transcriptome profiling of amyloid precursor protein family members in the adult cortex.
Sex, Specimen part
View Samples5,6-Dimethylxanthenone-4-acetic acid (DMXAA), a tumor vascular disrupting agent, is shown here to have substantial activity as a single agent against human A375 melanoma xenografts in nude mice (94 % hemorrhagic necrosis after 24 h, and 26 days growth delay following single dose at 25 mg/kg). CD45+ cells in tumor tissue increased 5-fold over the first 3 days after treatment, which was due largely to an influx of CD11b+ Ly6G+ neutrophils. Using murine and human multiplex cytokine assays to dissect the cytokines produced by host stromal cells or by the melanoma cells, it was shown that both the stromal cells and the A375 melanoma cells produced cytokines capable of attracting neutrophils into the tumor. The same xenografts were also analyzed using human and mouse Affymetrix microarrays to separately identify tumor cell-specific (human) and stromal cell-specific (mouse) gene expression changes. DMXAA induced numerous stromal cytokine mRNAs, including IP-10, IL-6, MIP-1/, MIP-2, KC, RANTES, MIG, MCP-1 and IL-1, many of which were also elevated at the protein level. Numerous human cytokine mRNAs were also induced including MCP-1, IL-8, GRO, VEGF, GM-CSF and IL-6, which again was in line with our protein data. Pathway analysis indicated that significant numbers of the stromal mRNAs induced by DMXAA are regulated downstream of TNF-, interferon- and NFB. Our results suggest that DMXAA may have utility in combination therapy for human melanoma through the activation of pro-inflammatory signalling pathways and cytokine expression from both stromal and tumor cells, leading to haemorrhagic necrosis, neutrophil influx and growth inhibition.
Dissection of stromal and cancer cell-derived signals in melanoma xenografts before and after treatment with DMXAA.
Specimen part, Cell line
View SamplesTo determine the modulation of gene expression of mouse BMDCs in the presence of living intracellular Leishmania amazonensis amastigotes
Sorting of Leishmania-bearing dendritic cells reveals subtle parasite-induced modulation of host-cell gene expression.
Sex, Age
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Transcriptomic response of murine liver to severe injury and hemorrhagic shock: a dual-platform microarray analysis.
Sex, Specimen part
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