Phloem-feeding pests cause extensive crop damage throughout the world yet little is understood about how plants perceive and defend themselves from these threats. The silverleaf whitefly (SLWF; Bemisia tabaci type B) is a good model for studying phloem-feeding insect-plant interactions as SLWF nymphs cause little wounding and have a long, continuous interaction with the plant. Using the Arabidopsis ATH1 GeneChip, the global responses to Silverleaf Whitefly 2nd instar feeding were examined.
Arabidopsis transcriptome changes in response to phloem-feeding silverleaf whitefly nymphs. Similarities and distinctions in responses to aphids.
Age
View SamplesTo identify epigenetically silenced genes in multiple myeloma (MM) cell lines and to determine the effects of 5-aza-2-deoxycytidine and trichostatin A on gene expression. We treated 3 multiple myeloma cell lines (MM1, NCI-H929, U266) with 5-aza-2-deoxycytidine and/or trichostatin A.
Genome-wide transcriptional response to 5-aza-2'-deoxycytidine and trichostatin a in multiple myeloma cells.
Specimen part, Disease, Cell line
View SamplesPBMC from house dust mite (HDM) sensitized atopics were cultured in the presence or absence of HDM extract for 24 hours.
Distinguishing benign from pathologic TH2 immunity in atopic children.
No sample metadata fields
View SamplesGene expression analysis has been established as a tool for the characterization of genotoxic mechanisms of chemical mutagens. This approach has been shown to differentiate between DNA reactive genotoxins and non-DNA reactive or indirectly-acting genotoxins. In this context, it has been suggested that expression analysis is capable of distinguishing compounds that cause DNA damage from those that interfere with mitotic spindle function. Formaldehyde (FA) is known to be a DNA-reactive substance which mainly induces chromosomal damage in cultured mammalian cells. However, there has been concern that FA might also act as an aneugen (i.e., induce aneuploidy) but recent cytogenetic studies did not support this assumption. To further characterize FA's genotoxic mode of action, we now used gene expression profiling as a molecular tool to differentiate between clastogenic and aneugenic activity. TK6 cells were exposed to FA for 4 and 24 h and changes in gene expression were analyzed using a whole-genome human microarray. Results were compared to the expression profiles of two DNA-damaging clastogens (methyl methanesulfonate [MMS] and ethyl methanesulfonate [EMS]) and two aneugens (colcemid [COL] and vincristine [VCR]). The gene expression profiles indicated that clastogens and aneugens induce discriminable gene expression patterns. The expression profile of FA showed more similarities to clastogens than to aneugens. Hierarchical clustering analysis as well as several class prediction algorithms revealed a much closer relationship of FA with clastogens than with aneugens. A pathway analysis of differentially regulated genes also demonstrated an overall better agreement of FA with clastogens than with aneugens. Altogether, the results of this study revealed great similarities in gene expression in response to FA and clastogens but did not support an aneugenic activity of FA.
Characterization of formaldehyde's genotoxic mode of action by gene expression analysis in TK6 cells.
Cell line, Treatment
View SamplesUsing various exposure conditions, we studied the induction of DNA-protein crosslinks (DPX) by formaldehyde (FA) and their removal in primary human nasal epithelial cells (HNEC). DPX were indirectly measured by the alkaline comet assay as the reduction of gamma ray induced DNA migration. DPX are the most relevant primary DNA alterations induced by FA and the comet assay is a very sensitive method for the detection of FA-induced DPX. In parallel experiments, we investigated changes in gene expression by using a full genome human microarray. After a single treatment with FA (50 to 200 M), concentration and time-dependent changes in gene expression were seen under conditions that also induced genotoxicity. Repeated treatments with low FA concentrations (20 and 50 M) did not lead to a significant induction of DPX but repeated treatments with 50 M FA changed the expression of more than 100 genes. Interestingly, the expression of genes involved in the main pathway for FA detoxification and the repair of DPX were not specifically enhanced. A high degree of overlap was seen among the pattern of gene changes induced by FA in HNEC in comparison to recently published array studies for nasal epithelial cells from rats exposed to FA in vivo. Our results suggest that HNEC are a suited in vitro model for the characterization of FA-induced toxicity and the relationship between genotoxic and other cytotoxic effects.
Gene expression changes in primary human nasal epithelial cells exposed to formaldehyde in vitro.
Specimen part, Treatment
View SamplesPBMC from house dust mite (HDM) sensitized atopics with or without asthma (or nonallergic controls) were cultured in the presence or absence of HDM extract for 24 hours.
Differential gene network analysis for the identification of asthma-associated therapeutic targets in allergen-specific T-helper memory responses.
Specimen part, Disease stage, Subject
View SamplesBACKGROUND: Streptococcus pneumoniae, the pneumococcus, is the main etiological agent of pneumonia. Pneumococcal infection is initiated by bacterial adherence to lung epithelial cells. The exact transcriptional changes occurring in both host and microbe during infection are unknown. Here, we developed a time-resolved infection model of human lung alveolar epithelial cells by S. pneumoniae and assess the resulting transcriptome changes in both organisms simultaneously by using dual RNA-seq. RESULTS: Functional analysis of the time-resolved dual RNA-seq data identifies several features of pneumococcal infection. For instance, we show that the glutathione-dependent reactive oxygen detoxification pathway in epithelial cells is activated by reactive oxygen species produced by S. pneumoniae. Addition of the antioxidant resveratrol during infection abates this response. At the same time, pneumococci activate the competence regulon during co-incubation with lung epithelial cells. By comparing transcriptional changes between wild-type encapsulated and mutant unencapsulated pneumococci, we demonstrate that adherent pneumococci, but not free-floating bacteria, repress innate immune responses in epithelial cells including expression of the chemokine IL-8 and the production of antimicrobial peptides. We also show that pneumococci activate several sugar transporters in response to adherence to epithelial cells and demonstrate that this activation depends on host-derived mucins. CONCLUSIONS: We provide a dual-transcriptomics overview of early pneumococcal infection in a time-resolved manner, providing new insights into host-microbe interactions. To allow easy access to the data by the community, a web-based platform was developed ( http://dualrnaseq.molgenrug.nl ). Further database exploration may expand our understanding of epithelial-pneumococcal interaction, leading to novel antimicrobial strategies. Overall design: 5 time points are analysed (0, 30, 60, 120 and 240 minutes after infection). Each time point has two biological replicates except for the 240 mpi. Furthermore, each time point has two pneumococcal strains used to infect A549 cells, encapsulated and unencapsulated pneumococci. In total there are 18 samples. cellular infection model, contains rRNA-depleted total RNA from A549 epithelial cells and D39 S. pneumoniae
Time-resolved dual RNA-seq reveals extensive rewiring of lung epithelial and pneumococcal transcriptomes during early infection.
Specimen part, Cell line, Subject
View SamplesAnalysis of five Notch signaling-dependent human T-ALL cell lines (ALLSIL, DND41, HPBALL, KOPTK1, TALL-1) treated with gamma-secretase inhibitor (GSI) to block Notch signaling. Samples include parental cells, cells rescued by retroviral transduction with ICN (a GSI-independent form of activated Notch1), and cells retrovirally transduced with c-Myc (an important downstream target of Notch1). Results allow segregation of bona fide Notch targets from other genes affected by gamma-secretase inhibition as well as from targets downstream of c-Myc.
High-level IGF1R expression is required for leukemia-initiating cell activity in T-ALL and is supported by Notch signaling.
Cell line
View SamplesAnalysis of expression profiles of human pDC cell line (CAL1) compared to an immature T cell line (MOLT4)
Transcription factor E2-2 is an essential and specific regulator of plasmacytoid dendritic cell development.
No sample metadata fields
View SamplesAnalysis of expression profiles of pDCs from wild type and heterozygous E2-2 mice. Results show the control by E2-2 of the expression of pDC-enriched genes.
Transcription factor E2-2 is an essential and specific regulator of plasmacytoid dendritic cell development.
No sample metadata fields
View Samples