Sepsis is a clinical syndrome that can be caused by bacteria or fungi. Early knowledge on the nature of the causative agent is a prerequisite for targeted anti-microbial therapy. Besides currently used detection methods like blood culture and PCR-based assays, the analysis of the transcriptional response of the host to infecting organisms holds great promise. In this study, we aim to examine the transcriptional footprint of infections caused by the bacterial pathogens Staphylococcus aureus and Escherichia coli and the fungal pathogens Candida albicans and Aspergillus fumigatus in a human whole-blood model. Moreover, we use the expression information to build a random forest classifier to determine if the pathogen is bacterial, fungal or neither of the two. After normalizing the transcription intensities using stably expressed reference genes, we filtered the gene set for biomarkers of bacterial or fungal blood infections. This selection is based on differential expression and an additional gene relevance measure. In this way, we identified 38 biomarker genes, including IL6, SOCS3, and IRG1 which were already associated to sepsis by other studies. Using these genes, we trained the classifier and assessed its performance. It yielded a 96% accuracy (sensitivities >93%, specificities >97%) for a 10-fold stratified cross-validation and a 92% accuracy (sensitivities and specificities >83%) for an additional dataset comprising Cryptococcus neoformans infections. Furthermore, the noise-robustness of the classifier suggests high rates of correct class predictions on datasets of new species. In conclusion, this genome-wide approach demonstrates an effective feature selection process in combination with the construction of a well-performing classification model. Further analyses of genes with pathogen-dependent expression patterns can provide insights into the systemic host responses, which may lead to new anti-microbial therapeutic advances.
Biomarker-based classification of bacterial and fungal whole-blood infections in a genome-wide expression study.
Sex, Specimen part, Subject, Time
View SamplesDCs are localized under the mucosa of the lungs and the gastrointestinal tract, and therefore come into close contact with A. fumigatus germ tubes during early steps of infection as soon as fungi become invasive. For a more detailed insight into differentially regulated genes, whole genome microarray analysis was performed.
Impact of mycophenolic acid on the functionality of human polymorphonuclear neutrophils and dendritic cells during interaction with Aspergillus fumigatus.
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View SamplesIn a whole-transcriptome study, cellular responses of DCs confronted with the fungi A. fumigatus, C. albicans or the bacterial cell wall component LPS were investigated. Therefore DCs of four independent donors were analyzed after 6 hours co-culture with A. fumigatus, C. albicans and LPS by Affymetrix whole genome expression arrays. In general, transcriptomic analysis revealed a clustering of the A. fumigatus and C. albicans stimulated DCs. However, LPS and fungi-dependent gene expression showed more common similarities compared to the untreated control. Stimulation with LPS induced a differential regulation of 2793 genes after 6h, while confrontation with A. fumigatus and C. albicans resulted in 743 and 974 differentially regulated genes, respectively. Kruppel-like factor 4 (KLF4) was identified as the only transcription factor that was down-regulated in DCs by both fungi but induced by stimulation with LPS.
Krüppel-like Factor 4 modulates interleukin-6 release in human dendritic cells after in vitro stimulation with Aspergillus fumigatus and Candida albicans.
Specimen part, Subject
View SamplesIn a whole-transcriptome study, cellular responses of DCs confronted with the fungi A. fumigatus, C. albicans or the bacterial cell wall component lipopolysaccharide (LPS) were investigated. Therefore, DCs of four independent donors were harvested after 12 hours co-culture with A. fumigatus, C. albicans and LPS and analyzed with Affymetrix whole genome expression arrays. In general, transcriptomic analysis revealed a clustering of the A. fumigatus- and C. albicans-stimulated DCs. However, LPS and fungi-dependent gene expression showed more common similarities compared to the untreated control.
Specific and Novel microRNAs Are Regulated as Response to Fungal Infection in Human Dendritic Cells.
Specimen part, Treatment, Subject
View SamplesMicroarray data of mouse primary E2A-PBX1 leukemias and preleukemia cells were compared to wild-type B-cell progenitor cells
E2A-PBX1 Remodels Oncogenic Signaling Networks in B-cell Precursor Acute Lymphoid Leukemia.
Sex, Specimen part
View SamplesAlpha-synuclein is an abundant protein implicated in synaptic function and plasticity, but the molecular mechanism of its action is not understood. Missense mutations and gene duplication/triplication events result in Parkinson's disease, a neurodegenerative disorder of old age with impaired movement and emotion control. Here, we systematically investigated the striatal as well as the cerebellar transcriptome profile of alpha-synuclein-deficient mice via a genome-wide microarray survey in order to gain hypothesis-free molecular insights into the physiological function of alpha-synuclein. A genotype-dependent, specific and strong downregulation of forkhead box P1 (Foxp1) transcript levels was observed in all brain regions from postnatal age until old age and could be validated by qPCR. In view of the co-localization and heterodimer formation of FOXP1 with FOXP2, a transcription factor with a well established role for vocalization, and the reported regulation of both alpha-synuclein and FOXP2 expression during avian song learning, we performed a detailed assessment of mouse movements and vocalizations in the postnatal period. While there was no difference in isolation-induced behavioral activity in these animals, the alpha-synuclein-deficient mice exhibited an increased production of isolation-induced ultrasonic vocalizations (USVs). This phenotype might also reflect the reduced expression of the anxiety-related GABA-A receptor subunit gamma 2 (Gabrg2) we observed. Taken together, we identified an early behavioral consequence of alpha-synuclein deficiency and accompanying molecular changes, which supports the notion that the neural connectivity of sound or emotion control systems is affected.
Alpha-synuclein deficiency affects brain Foxp1 expression and ultrasonic vocalization.
Age, Specimen part
View SamplesWe are using the ACI rat model of 17beta-estradiol induced mammary cancer to define the mechanisms through which estrogens contribute to breast cancer development; identify and functionally characterize the genetic variants that determine susceptibility; and define the hormone-gene-environment interactions that influence development of mammary cancer in this physiologically relevant rat model. Female ACI rats are uniquely susceptible to development of mammary cancer when treated continuously with physiologic levels of 17beta-estradiol. Induction of mammary cancer in female ACI rats occurs through a mechanism that is largely dependent upon estrogen receptor-alpha. Interval mapping analyses of progeny generated in intercrosses between susceptible ACI rats and resistant Brown Norway (BN) rats revealed seven quantitative trait loci (QTL), designated Emca3 (Estrogen-induced mammary cancer) through Emca9, each of which harbors one or more genetic determinants of mammary cancer susceptibility. Genes that reside within Emca8 on RNO5 and were differentially expressed between 17beta-estradiol treated ACI and ACI.BN-Emca8 congenic rats were identified as Emca8 candidates.
Mapping of three genetic determinants of susceptibility to estrogen-induced mammary cancer within the Emca8 locus on rat chromosome 5.
Sex, Age, Specimen part
View SamplesPlasticity between adhesive and less-adhesive states is important for mammalian cell behaviour. To investigate adhesion plasticity, we have selected a stable isogenic subpopulation of MDA-MB-468 breast carcinoma cells which grows in suspension. These suspension cells are unable to re-adhere to various matrices or to contract three-dimensional collagen lattices.
A dual phenotype of MDA-MB-468 cancer cells reveals mutual regulation of tensin3 and adhesion plasticity.
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View SamplesHow genomic information is selectively utilized to direct spatial and temporal gene expression patterns during differentiation remains to be elucidated but it is clear that regulated changes in higher-order genomic architecture plays a fundamental role. Specifically, long range interactions within and between chromosomes and the position of chromosome territories in the nucleus are controlled by TADs and LADs respectively, but the relationship between these genomic organizers remains poorly understood Overall design: We analyzed the large-scale spatial reorganization of chromatin by generating matched Hi-C and nuclear lamin-chromatin contact datasets throughout a dual adipose/neuronal induction of human primary adipose stem cells. We have mapped Hi-C (TADs) and lamin-associated domains (LADs) in multiple steps during adipose stem cell differentiation to characterize the spatial and temporal link between genomic architecture and gene expression. We identify a new level of 4D genomic organization involving a long-range clustering of individual TADs or TAD pairs into TAD cliques. LADs appear to regulate their formation. (ASCs). We unveil a lineage-specific dynamic assembly and disassembly of repressive cliques of linearly non-contiguous TADs, and a time course-coupled relationship between TAD clique size and lamina association. Our findings reveal a new level of developmental genome organization and provide an overview of large-scale changes in the 4D nucleome during lineage-specific differentiation.
Long-range interactions between topologically associating domains shape the four-dimensional genome during differentiation.
No sample metadata fields
View SamplesTo clarify mineralcorticoid receptor and glucocorticoid receptor-dependent gene networks in decidualizing human endometrial stromal cells.
Induction of 11β-HSD 1 and activation of distinct mineralocorticoid receptor- and glucocorticoid receptor-dependent gene networks in decidualizing human endometrial stromal cells.
Sex, Age, Specimen part, Treatment
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