Silver nanoparticles are used in consumer products like food contact materials, drinking water technologies and supplements, due to their antimicrobial properties. This leads to an oral uptake and exposure of intestinal cells. In contrast to other studies we found no apoptosis induction by surfactant coated silver nanoparticles in the intestinal cell model Caco-2 in a previous study, although the particles induced oxidative stress, morphological changes and cell death. Therefore, this study aimed to analyze the molecular mechanism of silver nanoparticles in Caco-2 cells. We used global gene expression profiling in differentiated Caco-2 cells, supported by verification of the microarray data by quantitative real time RT-PCR and microscopic analysis, impedance measurements and assays for apoptosis and oxidative stress. Our results revealed that the majority of surfactant coated silver nanoparticles are not taken up into differentiated Caco-2 cells. and probably affect the cells by outside-in signaling. They induce oxidative stress and have an influence on canonical pathways related to FAK, ILK, ERK, MAPK, integrins and adherence and tight junctions, thereby inducing transcription factors like AP1, NFB and NRF2, which mediate cellular reactions in response to oxidative stress and metal ions and induce changes in the cytoskeleton and cell-cell and cell-matrix contacts. The present data confirm the absence of apoptotic cell death. Non-apoptotic, necrotic cell death, especially in the intestine, can cause inflammation and influence the mucosal immune response.
Molecular mechanism of silver nanoparticles in human intestinal cells.
Cell line
View SamplesEarly rapid changes in response to the phytohormone abscisic acid (ABA) have been observed at the transcript level, but little is known how these transcript changes translate to changes in protein abundance under the same conditions. Here we have performed a global quantitative analysis of transcript and protein changes in Arabidopsis suspension cells in response to ABA using microarrays and quantitative proteomics. In summary, 3494 transcripts and 50 proteins were significantly regulated by ABA over a treatment period of 2024 h. Abscisic acid also caused a rapid and strong increase in production of extracellular reactive oxygen species (ROS) with an average half-rise time of 33 sec. A subset of ABA-regulated transcripts were differentially regulated in the presence of the ROS scavenger dimethylthiourea (DMTU) as compared with ABA alone, suggesting a role for ROS in the regulation of these ABA-induced genes. Transcript changes showed an overall poor correlation to protein changes (r = 0.66). Only a subset of genes was regulated at the transcript and protein level, including known ABA marker genes. We furthermore identified ABA regulation of proteins that function in a branch of glucosinolate catabolism previously not associated with ABA signaling. The discovery of genes that were differentially regulated at the transcript and at the protein level emphasizes the strength of our combined approach. In summary, our dataset not only expands previous studies on gene and protein regulation in response to ABA, but rather uncovers unique aspects of the ABA regulon and gives rise to additional mechanisms regulated by ABA.
Quantitative transcriptomic analysis of abscisic acid-induced and reactive oxygen species-dependent expression changes and proteomic profiling in Arabidopsis suspension cells.
Age, Specimen part, Cell line, Time
View SamplesThe goal of this study is to define the global gene expression profile of primary leukemic blasts from patients with different forms of myeloid leukemia and different FAB subtypes.
miR-125b-2 is a potential oncomiR on human chromosome 21 in megakaryoblastic leukemia.
Specimen part, Disease
View SamplesThe goal of this study is to define miR-125b-2 target genes in the hematopoietic system by genetic alteration of miR-125b expression levels.
miR-125b-2 is a potential oncomiR on human chromosome 21 in megakaryoblastic leukemia.
Specimen part, Cell line
View SamplesTo understand differences in the pathogenesis of synovial hyperplasia during TNF-induced arthritis, we compared the global gene expression of hTNFtg and hTNFtg;Rsk2-/y primary synovial fibroblasts.
Rsk2 controls synovial fibroblast hyperplasia and the course of arthritis.
Sex, Specimen part
View SamplesRedox Responsive Transcription Factor1 (RRTF1) in Arabidopsis is rapidly and transiently upregulated by H202, as well as biotic and abiotic induced redox signals. Inactivation of RRTF1 restricts and overexpression promotes reactive oxygen species (ROS) accumulation in response to stress. Overexpressor (oe) lines are impaired in root and shoot development, light sensitive and susceptible to Alternaria brassicae infection. These symptoms are diminished by the beneficial root endophyte Piriformospora indica which reduces ROS accumulation locally in roots and systemically in shoots, and by antioxidants and ROS inhibitors which scavenge ROS. More than 850 stress-, redox-, ROS regulated-, ROS scavenging-, defense-, cell death- and senescence-related genes are regulated by RRTF1, ~ 30% of them have ROS related functions. Bioinformatic analyses and in vitro DNA binding assays demonstrate that RRTF1 binds to GCC-box and GCC-box like sequences in the promoter of RRTF1-responsive genes. Upregulation of RRTF1 by stress stimuli as well as H2O2 requires WRKY18/40/60. RRTF1 is co-regulated with the phylogenetically related RAP2.6, which contains GCC-box like sequene in its promoter, but RAP2.6 oe lines do not accumulate higher ROS levels. RRTF1 stimulates systemic ROS accumulation in distal non-stressed leaves. We conclude that the highly conserved RRTF1 rapidly, transiently and systemically induce ROS accumulation in response to ROS and ROS-producing abiotic and biotic stress signals. Necrotrophs stimulate RRTF1 expression, while symbiotic interactions of Arabidopsis with (hemi)-biotrophs and P. indica do not affect or repress RRTF1 expression.
High REDOX RESPONSIVE TRANSCRIPTION FACTOR1 Levels Result in Accumulation of Reactive Oxygen Species in Arabidopsis thaliana Shoots and Roots.
Specimen part
View SamplesRedox Responsive Transcription Factor1 (RRTF1) in Arabidopsis is rapidly and transiently upregulated by H202, as well as biotic and abiotic induced redox signals. Inactivation of RRTF1 restricts and overexpression promotes reactive oxygen species (ROS) accumulation in response to stress. Overexpressor (oe) lines are impaired in root and shoot development, light sensitive and susceptible to Alternaria brassicae infection. These symptoms are diminished by the beneficial root endophyte Piriformospora indica which reduces ROS accumulation locally in roots and systemically in shoots, and by antioxidants and ROS inhibitors which scavenge ROS. More than 850 stress-, redox-, ROS regulated-, ROS scavenging-, defense-, cell death- and senescence-related genes are regulated by RRTF1, ~ 30% of them have ROS related functions. Bioinformatic analyses and in vitro DNA binding assays demonstrate that RRTF1 binds to GCC-box and GCC-box like sequences in the promoter of RRTF1-responsive genes. Upregulation of RRTF1 by stress stimuli as well as H2O2 requires WRKY18/40/60. RRTF1 is co-regulated with the phylogenetically related RAP2.6, which contains GCC-box like sequene in its promoter, but RAP2.6 oe lines do not accumulate higher ROS levels. RRTF1 stimulates systemic ROS accumulation in distal non-stressed leaves. We conclude that the highly conserved RRTF1 rapidly, transiently and systemically induce ROS accumulation in response to ROS and ROS-producing abiotic and biotic stress signals. Necrotrophs stimulate RRTF1 expression, while symbiotic interactions of Arabidopsis with (hemi)-biotrophs and P. indica do not affect or repress RRTF1 expression.
High REDOX RESPONSIVE TRANSCRIPTION FACTOR1 Levels Result in Accumulation of Reactive Oxygen Species in Arabidopsis thaliana Shoots and Roots.
Age, Specimen part
View SamplesCoordinated regulation of protection mechanisms against environmental abiotic stress and pathogen attack is essential for plant adaptation and survival. Initial abiotic stress can interfere with disease resistance signaling. Conversely, initial plant immune signaling may interrupt subsequent ABA signal transduction. However, the processes involved in cross talk between these signaling networks have not been determined. By screening a 9,600 compound chemical library, we identified a small molecule [5-(3,4-Dichlorophenyl)Furan-2-yl]-Piperidin-1-ylMethanethione that rapidly down-regulates ABA-dependent gene expression and also inhibits ABA-induced stomatal closure. Transcriptome analyses show that DFPM also stimulates expression of plant defense-related genes. Plate grown 12-day-old seedlings were transferred into 6 well plates with 1:5000 (V/V) DMSO in water as a control, 30uM DFPM, and 10uM ABA in water as a treatment for 6 hours. DFPM was added 30 min prior to ABA treatment. RNA was extracted using Trizol (Invitrogen, Carlsbad, CA, USA) and further purified using RNeasy Plant RNA purification kit (QIAgen, Valencia, CA, USA). Three biological replicates of ATH1 oligonucleotide arrays were hybridized with labeled samples from 1) wild-type Columbia (WT) untreated, 2) WT with 30uM DFPM treatment, 3) WT with 10uM ABA treatment, 4) WT with 30uM DFPM and 10uM ABA treatment. Each biological replicate was prepared by combining 7 independently-treated samples.
Chemical genetics reveals negative regulation of abscisic acid signaling by a plant immune response pathway.
Age
View SamplesSkeletal muscle biopsies from DM1, DM2, idiopathic DM (DMx), and non-DM NMD patients were compared to those from normal individuals, with focus on MEF2 and MEF2-related genes.
Altered MEF2 isoforms in myotonic dystrophy and other neuromuscular disorders.
Sex
View SamplesCHD4 is an ATPase able to use the energy from ATP to shift or remove nucleosomes from specific sites in the chromatin, thereby affecting accessability of gene regulatory elements. It is part of the NuRD complex.
Helicase CHD4 is an epigenetic coregulator of PAX3-FOXO1 in alveolar rhabdomyosarcoma.
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