Elevated levels of adsorbable organic bromine compounds (AOBr) have been detected in German lakes, and cyanobacteria like Microcystis, which are known for the synthesis of microcystins, are one of the main producers of natural organobromines. However, very little is known about how environmental realistic concentrations of organobromines impact invertebrates. Here, the nematode C. elegans was exposed to AOBr-containing surface water samples and to a Microcystis aeruginosa enriched batch culture (MC-BA) and compared to single organobromines and microcystin-LR exposures. Stimulatory effects were observed in certain life trait variables, which were particularly pronounced in nematodes exposed to MC-BA. A whole genome DNA-microarray revealed that MC-BA led to the differential expression of more than 2000 genes, many of which are known to be involved in metabolic, neurologic, and morphologic processes. Moreover, the up-regulation of cyp- and the down-regulation of abu-genes suggested the presence of chronic stress. However, the nematodes were not marked by negative phenotypic responses. The observed difference in MC-BA and microcystin-LR (which impacted lifespan, growth and reproduction) exposed nematodes was hypothesized to be likely due to other compounds within the batch culture. Most likely the exposure to low concentrations of organobromines appears to buffer the effects of toxic substances, like microcystin-LR.
No associated publication
No sample metadata fields
View SamplesHead and neck cancer is a hetergeneous disease. Based on previoulsy defined molecular subtypes we associated gene expression with response to different compounds. We used microarry gene expression for molecular subtyping
Basal subtype is predictive for response to cetuximab treatment in patient-derived xenografts of squamous cell head and neck cancer.
No sample metadata fields
View SamplesUsing these samples, it has been shown that the transcriptional landscape in glomeruli of Ercc1[-/] mice at a rather young age of 14 weeks mimics that of mice which have undergone real-life renal aging. Thus, young Ercc1[-/] mice can be used as a model system for glomerular aging in future studies.
No associated publication
Age
View SamplesPhosphate (Pi) deficiency triggers the differential expression of a large set of genes, which communally adapt the plant to low Pi bioavailability.
Coexpression-based clustering of Arabidopsis root genes predicts functional modules in early phosphate deficiency signaling.
Specimen part
View SamplesThe CHLD and CHLM genes encode proteins involved in tetrapyrrole biosynthesis pathway. It was proposed that intermediates like magnesium protoporphyrin might play a role in retrograde plastid-to-nucleus signaling. In the present work we provide evidence that altered enzymes activity of the tetrapyrrole biosynthesis pathway are causing changes in gene expression of over 200 nuclear genes.
No associated publication
Age, Specimen part
View Samples5-aminolevulinic acid (ALA) is the common precursor of all biological synthezised tetrapyrroles. Inhibition of ALA synthesis results in decreased amounts of chlorophylls, heme, siroheme and phytochrome. It was previously shown that 4 out of 5 Arabidopsis mutants uncoupling nuclear gene expression from the physiological state of the chloroplast are affected in plant tetrapyrrole biosynthesis. It is common to all four mutants to show a reduced ALA formation.
Evidence for a Contribution of ALA Synthesis to Plastid-To-Nucleus Signaling.
Age, Specimen part
View SamplesTo investigate potential differences between strong and weak oscillators at the gene expression level we carried out a transcriptome analysis for each cell line. Our results indicate that phenotypic circadian clock differences are reflected by gene expression differences both in genes of the core network, but also in additional genes not directly associated with circadian clock functions.
Ras-mediated deregulation of the circadian clock in cancer.
Specimen part, Cell line, Time
View SamplesAnimal models have enhanced our understanding of the pathogenesis of autoimmune diseases. For these models, genetically identical, inbred mice have commonly been used. Different inbred mouse strains, however, show a high variability in disease manifestation. Identifying the factors that influence this disease variability could provide unrecognized insights into pathogenesis. We established a novel antibody transfer-induced model of epidermolysis bullosa acquisita (EBA), an autoimmune disease characterized by (muco)-cutaneous blistering caused by anti-type VII collagen (COL7) autoantibodies. Blistering after anti-COL7 IgG (directed against the von-Willebrand-factor A like domain 2) transfer showed clear variability among inbred mouse strains; i.e. severe cutaneous blistering and inflammation in C57Bl/6J, and absence of skin lesions in MRL/MpJ mice. The transfer of anti-COL7 IgG into irradiated, EBA-resistant MRL/MpJ mice, rescued by transplantation with bone marrow from EBA-susceptible B6.AK-H2k mice, induced blistering. To the contrary, irradiated EBA-susceptible B6.AK-H2k mice that were rescued using MRL/MpJ bone marrow were devoid of blistering. In vitro, immune complex activation of neutrophils from C57Bl/6J or MRL/MpJ mice showed an impaired ROS release from the latter, whereas no differences were observed after PMA activation. This finding was paralleled by divergent expression profiles of immune-complex activated neutrophils from either C57Bl/6J or MRL/MpJ mice. Collectively, we demonstrate that radiosensitive cells determine the varying extent of skin inflammation and blistering in the end-stage effector phase of EBA.
Radiosensitive Hematopoietic Cells Determine the Extent of Skin Inflammation in Experimental Epidermolysis Bullosa Acquisita.
Disease
View SamplesThe p53 family is known as a family of transcription factors with functions in tumor suppression and development. Whereas the central DNA binding domain is highly conserved among the three family members p53, p63 and p73, the C-terminal domains (CTDs) are diverse and subject to alternative splicing and post-translational modification. Here we demonstrate that the CTDs strongly influence DNA binding and transcriptional activity. While p53 and the p73 isoform p73gamma have basic CTDs and form weak sequence-specific protein-DNA complexes, the major p73 isoforms alpha, beta and delta have neutral CTDs and bind DNA strongly. A basic CTD has been previously shown to enable sliding along the DNA backbone and to facilitate the search for binding sites in the complex genome. Our experiments, however, reveal that a basic CTD also reduces protein-DNA complex stability, intranuclear mobility, promoter occupancy in vivo, transgene activation and induction of cell cycle arrest or apoptosis. A basic CTD in p53 and p73gamma therefore provides both positive and negative regulatory functions presumably to enable rapid switching of protein activity in response to stress. In contrast, most p73 isoforms exhibit constitutive DNA binding activity consistent with a predominant role in developmental control.
C-terminal diversity within the p53 family accounts for differences in DNA binding and transcriptional activity.
No sample metadata fields
View SamplesRibosome Profiling was employed to learn about Ribosome A-site occupancies in response to uL11 siRNA treatment or scrambled siRNA treatment in Cystic Fibrosis Bronchial Epithelial (CFBE) cells. Overall design: Ribosome Profiling of cells 96h after siRNA transfection
Slowing ribosome velocity restores folding and function of mutant CFTR.
Specimen part, Subject
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