BACKGROUND & AIMS: Inflammatory Bowel Disease (IBD) is a chronic inflammatory condition driven by loss of homeostasis between the mucosal immune system, the commensal gut microbiota, and the intestinal epithelium. Our overarching goal is to understand how these components of the intestinal ecosystem cooperate to control homeostasis and to identify novel signal transduction pathways that become dysregulated in IBD. METHODS: We have applied a multi-scale systems biology approach to a mouse model of chronic colitis. We combined quantitative measures of epithelial hyperplasia and immune infiltration with multivariate analysis of inter- and intra-cellular signaling molecules in order to generate a tissue level model of the inflamed disease state. We utilized the computational model to identify signaling pathways that were dysregulated in the context of colitis and then validated model predictions by measuring the effect of small molecule pathway inhibitors on colitis. RESULTS: Our data-driven computational model identified mTOR signaling as a potential driver of inflammation and mTOR inhibition reversed the molecular, immunological, and epithelial manifestations of colitis. Inhibition of Notch signaling, which induces epithelial differentiation, had the same effect, suggesting that the epithelial proliferation/differentiation state plays a key role in maintaining homeostasis of the colon. Confirming this, we found that colonic organoids grown ex vivo showed a similar relationship between proliferation and cytokine expression, even in the absence of gut bacteria and immune cells. CONCLUSIONS: Our study provides a tissue-level systems biology perspective of murine colitis and suggests that mTOR plays a key role in regulating colonic homeostasis by controlling epithelial proliferation/differentiation state.
The colonic epithelium plays an active role in promoting colitis by shaping the tissue cytokine profile.
Specimen part
View SamplesComparison of gene expression profile of Ewing sarcoma cells which have an exchange of the endogenous EWS/FLI1 to either wild-type or a turnover-deficient mutant EWS/FLI1. Most target genes are saturated as only a few target genes are soly driven by increasing protein amount.
Proteasomal Degradation of the EWS-FLI1 Fusion Protein Is Regulated by a Single Lysine Residue.
No sample metadata fields
View SamplesPURPOSE. During retinal degeneration, Müller glia cells respond to photoreceptor loss by undergoing reactive gliosis, with both detrimental and beneficial effects. Increasing our knowledge of the complex molecular response of Müller cells to retinal degeneration is thus essential for the development of new therapeutic strategies. The purpose of this work was to identify new factors involved in Müller cell response to photoreceptor cell death. METHODS. Whole transcriptome sequencing was performed from wild-type and degenerating rd10 mouse retinas at P30. The changes in mRNA abundance for several deregulated genes were assessed by RT-qPCR. Protein expression level and retinal cellular localization were determined by western-blot and immunohistochemistry, respectively. RESULTS. Pathway-level analysis from whole transcriptomic data revealed the Hippo/YAP pathway as one of the main signaling pathways altered in response to photoreceptor degeneration in rd10 retinas. We found that downstream effectors of this pathway, YAP and TEAD1, are specifically expressed in Müller cells and that their expression, at both the mRNA and protein levels, is increased in rd10 reactive Müller glia after the onset of photoreceptor degeneration. The expression of Ctgf and Cyr61, two target genes of the transcriptional YAP/TEAD complex, is also upregulated following photoreceptor loss. CONCLUSIONS. This work reveals for the first time that YAP and TEAD1, key downstream effectors of the Hippo pathway, are specifically expressed in Müller cells. We also uncovered a deregulation of the expression and activity of Hippo/YAP pathway components in reactive Müller cells under pathological conditions. Overall design: Retinal samples were harvested from C57Bl6/J and rd10 mouse retina at postnatal days 30 for whole transcriptome sequencing (RNAseq). Each sample included 2 frozen retina and experiments were performed in triplicate. RNA-seq transcriptome libraries were constructed from 1 ug of total RNA.
Retinal Degeneration Triggers the Activation of YAP/TEAD in Reactive Müller Cells.
Specimen part, Cell line, Subject
View SamplesResponsiveness of cells to alpha-toxin (Hla) from Staphylococcus aureus appears to occur in a cell-type dependent manner. Here, we compare two human bronchial epithelial cell lines, i.e. Hla-susceptible 16HBE14o- and Hla-resistant S9 cells, by a quantitative multi-omics strategy for a better understanding of Hla-induced cellular programs. Phosphoproteomics revealed a substantial impact on phosphorylation-dependent signaling in both cell models and highlights alterations in signaling pathways associated with cell-cell and cell-matrix contacts as well as the actin cytoskeleton as key features of early rHla-induced effects. Along comparable changes in down-stream activity of major protein kinases significant differences between both models were found upon rHla-treatment including activation of EGFR and MAPK1/3 signaling in S9 and repression in 16HBE14o- cells. System-wide transcript and protein expression profiling indicate induction of an immediate early response in either model. In addition, EGFR and MAPK1/3-mediated changes in gene expression suggest cellular recovery and survival in S9 cells but cell death in 16HBE14o- cells. Strikingly, inhibition of the EGFR sensitized S9 cells to Hla indicating that the cellular capacity of activation of the EGFR is a major protective determinant against Hla-mediated cytotoxic effects.
A multi-omics approach identifies key hubs associated with cell type-specific responses of airway epithelial cells to staphylococcal alpha-toxin.
Cell line
View SamplesTranscription factor complexes bind to regulatory sequences of genes, providing a system of individual expression regulation. Targets of distinct transcription factors usually map throughout the genome, without clustering. Nevertheless, highly and weakly expressed genes do cluster in separate chromosomal domains with an average size of 80 to 90 genes. We therefore asked whether, besides transcription factors, an additional level of gene expression regulation exists that acts on chromosomal domains. Here we show that identical green fluorescent protein (GFP) reporter constructs integrated at 90 different chromosomal positions determined by sequencing, obtain expression levels that correspond to the activity of the domains of integration. These domains are about 80 genes long and can exert an effect of up to 8-fold on the expression of integrated genes. 3D-FISH shows that active domains of integration have a more open chromatin structure than integration domains with weak activity. These results reveal a novel domain-wide regulatory mechanism that, together with transcription factors, exerts a dual control over gene transcription.
Domain-wide regulation of gene expression in the human genome.
No sample metadata fields
View SamplesThe three-dimensional (3D) folding of the chromosomal fibre in the human interphase nucleus is an important, but poorly understood aspect of gene regulation. Especially basic principles of 3D chromatin and chromosome organisation are still elusive. In this paper, we quantitatively analyse the 3D structure of large parts of chromosomes 1 and 11 in the G1 nucleus of human cells and relate it to the human transcriptome map (HTM). Despite a considerable cell-to-cell variation, our results show that subchromosomal domains, which are highly expressed, are more decondensed, have a more irregular shape and are located in the nuclear interior compared to clusters of low expressed genes. These aspects of chromosome structure are shared by six different cell lines and therefore are independent of cell type specific differences in gene expression within the investigated domains. Systematic measurements show that there is little to no intermingling of chromatin from different parts of the same chromosome, indicating that the chromosomal fibre itself is a compact structure. Together, our results reveal several basic aspects of 3D chromosome architecture, which are related to genome function.
The three-dimensional structure of human interphase chromosomes is related to the transcriptome map.
No sample metadata fields
View SamplesIn summary, we characterized genomic signatures of response to drugs of abuse and we found positive correlations between the drug-induced expression and various behavioral effects. These signatures are formed by two dynamically inducible transcriptional networks: (1) CREB/SRF-dependent gene pattern that appears to be related to drug-induced neuronal activity, (2) the pattern of genes controlled at least in part via release of glucocorticoids and androgens that are associated with rewarding and harmful drug effects. The discovery of co-expressed networks of genes allowed for the identification of master-switch controlling factors involved in molecular response to the drugs. Finally, using the pharmacological tools we were able to dissect and inhibit particular gene expression patterns from genomic profile.
The dissection of transcriptional modules regulated by various drugs of abuse in the mouse striatum.
Compound, Time
View SamplesThis study addresses long-term effects of clinically relevant regimens of radiation in human glioma stem cells. Our investigations reveal a strikingly diverse spectrum of changes in cell behavior, gene expression patterns and tumor-propagating capacities evoked by radiation in different types of glioma stem cells. Evidence is provided that degree of cellular plasticity but not the propensity to self-renew is an important factor influencing radiation-induced changes in the tumor-propagating capacity of glioma stem cells. Gene expression analyses indicate that paralell transcriptomic responses to radiation underlie similarity of clinically relevant cellular outcomes such as the ability to promote tumor growth after radiation. Our findings underscore the importance of longitudinal characterizations of molecular and cellular responses evoked by cytotoxic treatrments in glioma stem cells.
Diversity of Clinically Relevant Outcomes Resulting from Hypofractionated Radiation in Human Glioma Stem Cells Mirrors Distinct Patterns of Transcriptomic Changes.
Treatment
View SamplesPhotoreceptor degeneration is the central event leading to visual impairment or blindness in most retinal diseases. However, the discovery of safe and effective therapeutic strategies conferring photoreceptor protection remains challenging. A systems pharmacology approach, synergistically targeting distinct cellular pathways could provide an effective strategy for evaluating, preventing or treating retinal dystrophies. Here this concept was investigated using a mouse model of light-induced retinal degeneration. We show that a combination of FDA-approved drugs acting on different G protein-coupled receptors in a synergistic manner could protect retinas against light-induced degeneration when each drug in the combination treatment was administered at a sub-therapeutic dose. Furthermore, transcriptome analyses demonstrated that such combined treatments also preserved patterns of retinal gene expression more characteristic of the normal retina than did single therapies at higher doses. The current study thus supports a new systems pharmacology approach that may extend to other complex neurodegenerative disorders in addition to retinal diseases. Overall design: Male and female Abca4-/-Rdh8-/- at the age of 4- to 6-weeks were used for the current study. All mice were housed and maintained in a 12 h light (=10 lux)/12 h dark cyclic environment in the Animal Resource Center at the School of Medicine, Case Western Reserve University (CWRU). Bright light-induced retinal damage was generated by exposing Abca4-/-Rdh8-/- mice to white light delivered at 10,000 lux (150 W spiral lamp, Commercial Electric) for 30 min. All indicated treatments were administered by intraperitoneal injection 30 min prior to bright light exposure and retinas collected one day later. Single compounds and their tested doses were: 2-Bromo-a-ergocryptine methanesulfonate salt (BRM), metoprolol tartrate (MTP), tamsulosin (TAM), and doxazosin (DOX). Combined treatments were: BRM, MTP and TAM (BMT), or MTP, DOX, and BRM (MDB). Processed data files (linked as series supplementary files): DE_combined.txt; Significant differential expression results from the combined pretreatment experiment. DE_mono.txt; Significant differential expression results from the mono pretreatment experiment. eXpress_counts_combined.txt; Quantitation output from eXpress of effective counts from the combined pretreatment experiment. eXpress_counts_mono.txt; Quantitation output from eXpress of effective counts from the mono pretreatment experiment. eXpress_fpkm_combined.txt; Quantitation output from eXpress of fpkm values from the combined pretreatment experiment. eXpress_fpkm_mono.txt; Quantitation output from eXpress of fpkm values from the mono pretreatment experiment. normalized_fpkm_combined.txt; TMM normalized fpkm values from the combined pretreatment experiment. normalized_fpkm_mono.txt; TMM normalized fpkm values from the mono pretreatment experiment.
Synergistically acting agonists and antagonists of G protein-coupled receptors prevent photoreceptor cell degeneration.
Specimen part, Subject, Compound
View SamplesWe used adult male Sprague-Dawley rats (280-329 g body weight). Controls were nave rats. Ischemic rats were subjected to 1-hour occlusion of the right middle cerebral artery and 16h reperfusion.
CNS-border associated macrophages respond to acute ischemic stroke attracting granulocytes and promoting vascular leakage.
Sex, Specimen part
View Samples