Protein-RNA interactions are fundamental to core biological processes, such as mRNA splicing, localization, degradation and translation. We have developed a photoreactive nucleotide-enhanced UV crosslinking and oligo(dT) purification approach to identify the mRNA-bound proteome using quantitative proteomics and to display the protein occupancy on mRNA transcripts by next-generation sequencing (Baltz and Munschauer et al. 2012). Our current work focuses on streamlining and extending protein occupancy profiling on poly(A)-RNA. Our objectives are to identify previously unknown protein-bound transcripts and, more importantly, to assess global and local differences in protein occupancy across different biological conditions. To this end, we have implemented poppi, the first pipeline for differential analysis of protein occupancy profiles. We have applied our analysis pipeline to pinpoint changes in occupancy profiles of MCF7 cells against already published HEK293 cells [GSE38157]. Overall design: We generated protein occupancy cDNA libraries for two biological replicates. Briefly, we crosslinked 4SU-labeled MCF7 cells and purified protein-mRNA complexes using oligo(dT)-beads. The precipitate was treated with RNAse I to reduce the protein-crosslinked RNA fragments to a length of about 30-60 nt. To remove non-crosslinked RNA, protein-RNA complexes were precipitated with ammonium sulfate and blotted onto nitrocellulose. The RNA was recovered by Proteinase K treatment, ligated to cloning adapters, and reverse transcribed. The resulting cDNA libraries were PCR-amplified and next-generation sequenced.
Differential protein occupancy profiling of the mRNA transcriptome.
No sample metadata fields
View SamplesWe report that IL-17A has an inhibitory effect on osteoblastogenesis. Overall design: Pre-osteoblasts were treated with vehicle or 50ng/ml IL-17A for 7 days.
Chronic skin inflammation leads to bone loss by IL-17-mediated inhibition of Wnt signaling in osteoblasts.
No sample metadata fields
View SamplesCancer cells interact with surrounding stromal fibroblasts during tumorigenesis, but the complex molecular rules that govern these interactions remain poorly understood, thus hindering the development of therapeutic strategies to target cancer stroma. We have taken a mathematical approach to begin defining these rules by performing large-scale quantitative analysis of fibroblast effects on cancer cell proliferation across more than four hundred heterotypic cell line pairings. Systems-level modeling of this complex dataset using singular value decomposition revealed that normal tissue fibroblasts variably express at least two functionally distinct activities, one which reflects transcriptional programs associated with activated mesenchyme, that act either coordinately or at cross-purposes to modulate cancer cell proliferation. To gain insight into the molecular identity of these fibroblast activities, we isolated RNA from 36 human skin and lung fibroblast cell line monocultures from Coriell Repositories or ATCC and performed microarray-based gene expression profiling using Affymetrix gene chips.
Systems-level modeling of cancer-fibroblast interaction.
Sex, Age, Race
View SamplesSurgical interventions on blood vessels bear a risk for intimal hyperplasia and atherosclerosis as a consequence of injury. A specific feature of intimal hyperplasia is the loss of vascular smooth muscle cell (VSMC) differentiation gene expression. We hypothesized that immediate responses following injury induce vascular remodeling. To differentiate injury due to trauma, reperfusion and pressure changes we analyzed vascular responses to carotid artery bypass grafting in mice compared to transient ligation. As a control, the carotid artery was surgically laid open only. In both, bypass or ligation models, the inflammatory responses were transient, peaking after 6h, whereas the loss of VSMC differentiation gene expression persisted. Extended time kinetics showed that transient carotid artery ligation was sufficient to induce a persistent VSMC phenotype change throughout 28 days. Transient arterial ligation in ApoE knockout mice resulted in atherosclerosis in the transiently ligated vascular segment but not on the not-ligated contralateral side. The VSMC phenotype change could not be prevented by anti-TNF antibodies, Sorafenib, Cytosporone B or N-acetylcysteine treatment. Surgical interventions involving hypoxia/reperfusion are sufficient to induce VSMC phenotype changes and vascular remodeling. In situations of a perturbed lipid metabolism this bears the risk to precipitate atherosclerosis. Overall design: Comparison of mRNA changes between control tissue and bypass grafts perfused for 1, 6 and 24h. Number of replicated per group =4-5
Hypoxia/reperfusion predisposes to atherosclerosis.
Sex, Specimen part, Cell line, Subject
View SamplesThe ACBP knockout were created by targeted disruption of the gene in mice. The expression profiling was performed on liver tissue from ACBP-/- (KO) and +/+ (WT) mice at the age of 21 days, which in our study is the time immediately before weaning. The mice used for this experiment were taken directly away from their mother. Thus, having free access to chow and breast milk until sacrificed at 8-11am
Disruption of the acyl-CoA-binding protein gene delays hepatic adaptation to metabolic changes at weaning.
Specimen part
View SamplesInflammatory mechanisms have been suggested to play a role in the development of heart failure (HF), but a role for chemokines is largely unknown. The aim of this study was to analyze the role of the chemokine CXCL13 and its receptor CXCR5 in cardiac pathophysiology leading to HF
Lack of chemokine signaling through CXCR5 causes increased mortality, ventricular dilatation and deranged matrix during cardiac pressure overload.
Sex, Specimen part
View SamplesInduction of the Arf tumor suppressor in response to hyperproliferative stress following oncogene activation activates a p53-dependent transcriptional program that limits the expansion of incipient cancer cells. Although Arf is not expressed in most tissues of fetal or young adult mice, it is physiologically expressed in the fetal yolk sac, a tissue derived from the extraembryonic endoderm. We demonstrate that expression of the mouse p19Arf protein marks late stages of extraembryonic endoderm differentiation in cultured embryoid bodies derived from either embryonic stem cells or induced pluripotent stem cells, and that Arf inactivation specifically delays the differentiation of the extraembryonic endoderm lineage, but not the formation of other germ cell lineages from pluripotent progenitors. Arf is required for the timely induction of extraembryonic endodermal cells in response to Ras/Erk signaling and, in turn, acts through p53 to ensure extraembryonic endoderm lineage development, but not maintenance. Remarkably, a significant temporal delay in extraembryonic endoderm differentiation detected during the maturation of Arf-null embryoid bodies is rescued by enforced expression of miR-205, a micro-RNA up-regulated by p19Arf and p53. Introduction of miR-205 into Arf-null embryonic stem cells rescues defective ExEn formation and elicits a program of gene expression that controls the migration and adhesion of embryonic endodermal cells. This occurs, at least in part, through atypical regulation of genes that control the epithelial-to-mesenchymal transition in cancer cells. Our findings suggest that noncanonical and canonical roles of Arf in extraembryonic endoderm development and tumor suppression, respectively, may be conceptually linked through mechanisms that govern cell-to-cell attachment and migration.
Arf tumor suppressor and miR-205 regulate cell adhesion and formation of extraembryonic endoderm from pluripotent stem cells.
Specimen part, Treatment
View SamplesBackground: Although TNF inhibitors are used to treat chronic inflammatory diseases, there is little information about how long-term inhibition of TNF affects the homeostatic functions that TNF maintains in the intact CNS. TNF is known to modulate neurogenesis by decreasing cell proliferation, increasing apoptosis of precursor cells, and impairing neuronal differentiation. TNF can also influence the formation of the hippocampus, with long-lasting effects on cognition. Materials and methods: To clarify whether developmental TNF deficiency causes alterations in the naïve CNS, we estimated the number of proliferating cells, microglia, and neurons in the brains of E13.5, P7, and adult TNF +/+ and TNF-/- mice and measured changes in gene and protein expression and monoamine levels in adult TNF+/+ and TNF-/- mice. To evaluate long-term effects of TNF inhibitors, we treated healthy adult C57BL/6 mice with either saline, selective soluble TNF inhibitor XPro1595, or nonselective TNF inhibitor etanercept. We estimated changes in cell number and protein expression after two months of treatment. We assessed the effects of TNF deficiency on cognition by testing adult TNF+/+ and TNF-/- mice and anti-TNF treated mice with behavioral tasks.
TNF deficiency causes alterations in the spatial organization of neurogenic zones and alters the number of microglia and neurons in the cerebral cortex.
Sex, Specimen part
View SamplesExperimental asthma was induced in BALB/c mice by sensitization and challenge with the allergen ovalbumin. Control groups received PBS. To investigate the innate immune component of experimental asthma, we also analyzed recombinase activating gene (RAG) deficient mice following exposure to ovalbumin and control PBS
Hubs in biological interaction networks exhibit low changes in expression in experimental asthma.
No sample metadata fields
View SamplesLong-term pharmacological glucocorticoid therapy causes atrophy and hypofunction of the adrenal cortex. Following glucocorticoids withdrawal, a functional and anatomic regeneration take place, whose cellular and molecular mechanisms are poorly understood
Sonic Hedgehog and WNT Signaling Promote Adrenal Gland Regeneration in Male Mice.
Age, Specimen part
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