Purpose: Severe late normal tissue damage limits radiotherapy treatment regimens. This study aims to validate -H2AX foci decay ratios and induced expression levels of DNA double strand break (DSB) repair genes, found in a retrospective study, as possible predictors for late radiation toxicity. Methods and Materials: Prospectively, decay ratios (initial/residual -H2AX foci numbers) and genome-wide expression profiles were examined in ex vivo irradiated lymphocytes of 198 prostate cancer patients. All patients were followed 2 years after radiotherapy, clinical characteristics were assembled and toxicity was recorded using the Common Terminology Criteria (CTCAE) v4.0. Results: No clinical factors were correlated with late radiation toxicity. Analysis of -H2AX foci uncovered a negative correlation between the foci decay ratio and toxicity grade. Significantly smaller decay ratios were found in grade3 compared to grade 0 patients (p=0.02), indicating less efficient DNA-DSB repair in radio-sensitive patients. Moreover, utilizing a foci decay ratio threshold determined in our previous retrospective study correctly classified 23 of the 28 grade3 patients (sensitivity, 82%) and 9 of the 14 grade 0 patients (specificity, 64%). Grade of toxicity also correlated with a reduced induction of the homologous recombination (HR) repair gene-set. The difference in average fold induction of the HR gene-set was most pronounced between grade 0 and grade3 patients (p=0.008). Conclusions: Reduced responsiveness of HR repair genes to irradiation and inefficient DSB repair correlate with an increased risk of late radiation toxicity. Using a decay ratio classifier, we could correctly classify 82% of the patients with grade3 toxicity. Additional studies are required to further optimize and validate the foci decay assay and to assess its predictive value for late radiation toxicity in patients prostate cancer
Prostate Cancer Patients with Late Radiation Toxicity Exhibit Reduced Expression of Genes Involved in DNA Double-Strand Break Repair and Homologous Recombination.
Specimen part, Subject
View SamplesC/EBPalpha is a transcription factor critically involved in myeloid development and indispensable for formation of granulocytes. To track the cellular fate of stem and progenitor (LSK) cells, which express C/EBPalpha, we developed a mouse model expressing Cre recombinase from the Cebpa promoter and an inducible EYFP allele. We show that Cebpa/EYFP+ cells represent a significant subset of LSK cells, which predominantly give rise to myeloid cells in steady state hematopoiesis.
Lineage-instructive function of C/EBPα in multipotent hematopoietic cells and early thymic progenitors.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identification of Circulating Fibrocytes and Dendritic Derivatives in Corneal Endothelium of Patients With Fuchs' Dystrophy.
Sex, Age, Specimen part
View SamplesPURPOSE: Fuchs endothelial corneal dystrophy (FECD) is a degenerative eye disorder affecting 4% of Americans older than 40. It is the leading indication for corneal endothelial (CE) transplantation for which there is a global donor shortage. This study aimed to gain further insight into the pathophysiology of FECD and identify targets for nonsurgical therapy.
Identification of Circulating Fibrocytes and Dendritic Derivatives in Corneal Endothelium of Patients With Fuchs' Dystrophy.
Sex, Age, Specimen part
View SamplesIn the present study, we studied chronic HCV patients who responded to IFN-based therapy as evidenced by absence of HCV RNA at the end of treatment, and focused on two issues that have not received much attention. Firstly, we evaluated whether specific genes or gene expression patterns in blood were able to distinguish responder patients with a viral relapse from responder patients who remained virus-negative after cessation of treatment. We found that chronic HCV patients who were sustained responders and relapsers to IFN-based therapy showed comparable baseline clinical parameters and immune composition in blood. However, at baseline, the gene expression profiles of a set of 18 genes predicted treatment outcome with an accuracy of 94%. Secondly, we examined whether patients with successful therapy-induced clearance of HCV still exhibited gene expression patterns characteristic for HCV, or whether normalization of their transcriptome was observed. We observed that the relatively high expression of IFN-stimulated genes (ISG) in chronic HCV patients prior to therapy was reduced after successful IFN-based antiviral therapy (at 24 weeks follow-up). These ISG included CXCL10, OAS1, IFI6, DDX60, TRIM5 and STAT1. In addition, 1428 differentially expressed non-ISG genes were identified in paired pre- and post-treatment samples from sustained responders, which included genes involved in TGF- signaling, apoptosis, autophagy, and nucleic acid and protein metabolism. Interestingly, 1424 genes were identified with altered expression in responder patients after viral eradication in comparison to normal expression levels in healthy individuals. Additionally, aberrant expression of a subset of these genes, including IL-32, IL-16, CCND3 and RASSF1, was also observed at baseline. Our findings indicate that successful antiviral therapy of chronic HCV patients does not lead to normalization of their blood transcriptional signature. The altered transcriptional activity may reflect HCV-induced liver damage in previously infected individuals.
Gene expression profiling to predict and assess the consequences of therapy-induced virus eradication in chronic hepatitis C virus infection.
Sex, Specimen part, Disease, Race
View SamplesWe compared expression of genes in brains of SIRT1 brain-specific knockouts (BSKO) to those of wild-type littermate controls (WT).
SIRT1 activates MAO-A in the brain to mediate anxiety and exploratory drive.
Sex, Age, Specimen part
View SamplesATP6AP2 is an essential accessory component of the vacuolar H+ ATPase (V-ATPase) and has been associated with intellectual disabilities (ID) and Parkinsonism. ATP6AP2 has been implicated in several signaling pathways, but little is known about its role in the nervous system. To decipher its function in behaviour and cognition, we generated and characterized conditional ATP6AP2 Drosophila and mouse models in the nervous system. In Drosophila, knockdown of ATP6AP2 induced defective phototaxis and vacuolisation of photoreceptor neurons and pigment cells when deleted in eyes and alteration of short- and long-term memory when deleted in the mushroom body. In mouse, conditional Atp6ap2 deletion in glutamatergic neurons (Atp6ap2Camk2aCre/0 mice) caused increased spontaneous locomotor activity and altered memory for fear. Both Drosophila ATP6AP2 knockdown and Atp6ap2Camk2aCre/0 mice presented with presynaptic transmission defect, abnormal number and morphology of synapses, and alteration of axonal transport in fly. In addition, Atp6ap2Camk2aCre/0 mice showed autophagy defect leading to axonal and neuronal degeneration in the cortex and the hippocampus. Surprisingly, myelinisation of axons was affected in our mutant mice. In accordance with the identified phenotypes across species, genome-wide transcriptome profiling of Atp6ap2Camk2aCre/0 mouse hippocampi revealed dysregulated genes involved in myelination, action potential, membrane bound vesicles and adult behaviour. In summary, disruption of ATP6AP2 in mouse and fly leads to cognitive impairment and neurodegeneration, mimicking aspects of the neuropathology associated with ATP6AP2 mutations in humans. Our results identify ATP6AP2 as an essential gene for the nervous system. Overall design: 4 samples, 2 wt and 2 Atp6ap2Camk2aCre/0
Conditional depletion of intellectual disability and Parkinsonism candidate gene ATP6AP2 in fly and mouse induces cognitive impairment and neurodegeneration.
No sample metadata fields
View SamplesGlucocorticoid resistance (GCR) is defined as an unresponsiveness to the anti-inflammatory properties of glucocorticoids (GCs) and their receptor, the glucocorticoid receptor (GR). It is a serious problem in the management of inflammatory diseases and occurs frequently. The strong pro-inflammatory cytokine TNF induces an acute form of GCR, not only in mice, but also in several cell lines, e.g. in the hepatoma cell line BWTG3, as evidenced by impaired Dexamethasone (Dex)-induced GR-dependent gene expression. We report that TNF has a significant and broad impact on the transcriptional performance of GR, but no impact on nuclear translocation, dimerization or DNA binding capacity of GR. Proteome-wide proximity-mapping (BioID), however, revealed that the GR interactome is strongly modulated by TNF. One GR cofactor that interacts significantly less with the receptor under GCR conditions is p300. NF?B activation and p300 knockdown both reduce transcriptional output of GR, whereas p300 overexpression and NF?B inhibition revert TNF-induced GCR, which is in support of a cofactor reshuffle model. This hypothesis is supported by FRET studies. This mechanism of GCR opens new avenues for therapeutic interventions in GCR diseases Overall design: Examination of GR induced gene expression in 4 conditions (1 control: NI and 3 treated: DEX, TNF, TNFDEX) starting from 3 biological replicates
TNF-α inhibits glucocorticoid receptor-induced gene expression by reshaping the GR nuclear cofactor profile.
Specimen part, Cell line, Treatment, Subject
View SamplesThis experiment was set up in order to identify the (direct) transcriptional targets of the Ethylene Response Factor 115 (ERF115) transcription factor. Because ERF115 expression occurs in quiescent center (QC) cells and strong effects on the QC cells were observed in ERF115 overexpression plants, root tips were harvested for transcript profiling in order to focus on root meristem and QC specific transcriptional targets.
ERF115 controls root quiescent center cell division and stem cell replenishment.
Age, Specimen part
View SamplesMesenchymal progenitor cells can be differentiated in vitro into myotubes that exhibit many characteristic features of primary mammalian skeletal muscle fibers. However, in general, they do not show the functional excitation-contraction coupling or the striated sarcomere arrangement typical of mature myofibers. Epigenetic modifications have been shown to play a key role in regulating the progressional changes in transcription necessary for muscle differentiation. In this study, we demonstrate that treatment of murine C2C12 mesenchymal progenitor cells with 10 M of the DNA methylation inhibitor 5-azacytidine (5AC) promotes myogenesis, resulting in myotubes with enhanced maturity as compared to untreated myotubes. Specifically, 5AC treatment resulted in the upregulation of muscle genes at the myoblast stage while at later stages nearly 50 % of the 5AC-treated myotubes displayed a mature, well-defined sarcomere organization as well as spontaneous contractions that coincided with action potentials and intracellular calcium transients. Both the percentage of striated myotubes and their contractile activity could be inhibited by 20 nM TTX, 10 M ryanodine and 100 M nifedipine, suggesting that action potential-induced calcium transients are responsible for these characteristics. Our data suggest that genomic demethylation induced by 5AC overcomes an epigenetic barrier that prevents untreated C2C12 myotubes from reaching full maturity.
Epigenetics: DNA demethylation promotes skeletal myotube maturation.
Cell line, Treatment
View Samples