Oxidative stress is a hallmark of inflammation in infection or sterile tissue injury. We show that partially oxidized phospholipids of microvesicles (MVs) from plasma of patients with rheumatoid arthritis or cells exposed to oxidative stress induce activation of TLR4. MVs from healthy donors or reconstituted synthetic MVs can be converted to TLR4 agonists by limited oxidation, while prolonged oxidation abrogates the activity. Activation by MVs mimics the mechanism of TLR4 activation by LPS. However, LPS and MVs induce significantly different transcriptional response profile in mouse BMDMs with a strong inflammation-resolving component induced by the endogenous signals. MVs thus represent a ubiquitous endogenous danger signal released under the oxidative stress, which underlies the pervasive role of TLR4 signaling in inflammation.
Toll-like receptor 4 senses oxidative stress mediated by the oxidation of phospholipids in extracellular vesicles.
Sex
View SamplesmRNA expression profiles for 3 breast cancer cell lines seeded at different density and grown for different duration Overall design: This experiment is part of a study fo the effect of cell density on drug sensitivity [1]. Cells plated at different densities in 384-well plates were harvested at the indicated times and RNA was extracted using the RNeasy mini kit (Qiagen). To ensure sufficient RNA amounts wells with low cell numbers were pooled. Some conditions have been tested in biollogical replicates grown at the same time. Libraries were prepared by the Broad Technology Labs (BTL) following the protocol for SCRB-Seq described in [2]. Transcripts were quantified by the BTL computational pipeline using Cuffquant version 2.2.1 [3]. [1] Hafner, M., Niepel, M., Chung, M., Sorger, P.K., Growth rate inhibition metrics correct for confounders in measuring sensitivity to cancer drugs. DOI:10.1038/NMETH.3853 [2] Soumillon, M., Cacchiarelli, D., Semrau, S., van Oudenaarden, A. & Mikkelsen, T.S. Characterization of directed differentiation by high-throughput single-cell RNA-Seq http://biorxiv.org/content/early/2014/03/05/003236 [3] Trapnell, C., Roberts, A., Goff, L., Pertea, G., Kim, D., Kelley, D.R., Pimentel, H., Salzberg, S.L., Rinn, J.L. & Pachter, L. Differential gene and transcript expression analysis of RNA-seq experiments with TopHat and Cufflinks, Nat. Protoc. 7, 562-578 (2012).
Growth rate inhibition metrics correct for confounders in measuring sensitivity to cancer drugs.
Subject
View SamplesPost-transcriptional gene regulation by miRNAs and RNA binding proteins (RBP) is important in development, physiology and disease. To examine the interplay between miRNAs and the RBP ELAVL1 (a.k.a. HuR), we mapped miRNA binding sites on a transcriptome-wide scale in WT and Elavl1 knockout murine bone marrow-derived macrophages. Proximity of ELAVL1 binding sites attenuated miRNA binding to transcripts and promoted gene expression. Transcripts that regulate angiogenesis and macrophage/ endothelial cross talk were preferentially targeted by miRNAs, suggesting that ELAVL1 promotes angiogenesis, at least in part, by antagonism of miRNA function. We found that ELAVL1 antagonized binding of miR-27 to the 3'UTR of Zfp36 mRNA and alleviated miR-27-mediated suppression of the RBP ZFP36 (a.k.a. Tristetraprolin). Thus the miR-27-regulated mechanism synchronizes the expression of ELAVL1 and ZFP36. This study provides a resource for systems-level interrogation of post-transcriptional gene regulation in macrophages, a key cell type in inflammation, angiogenesis and tissue homeostasis. Overall design: Bone marrow derived macrpohges mRNA profiles of 7-day cultured wild type (WT) and Elavl1l-/- mouse bone marrow cells were generated by deep sequencing, with 4 biologic duplication, using Illumina GAII.
ELAVL1 modulates transcriptome-wide miRNA binding in murine macrophages.
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The human primary hepatocyte transcriptome reveals novel insights into atorvastatin and rosuvastatin action.
Specimen part, Subject, Time
View SamplesWith particular emphasis on interactions between cholesterol homeostasis and drug metabolism we investigate the transcriptome of human primary hepatocytes treated by two commonly prescribed cholesterol lowering drugs atorvastatin and rosuvastatin and by rifampicin that serves as an outgroup as well as a model substance for induction of nuclear receptor PXR.
The human primary hepatocyte transcriptome reveals novel insights into atorvastatin and rosuvastatin action.
Specimen part, Subject, Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Global target mRNA specification and regulation by the RNA-binding protein ZFP36.
Cell line, Treatment
View SamplesTristetraprolin/ZFP36/TTP and ELAVL1/HuR are two disease-relevant RNA-binding proteins (RBPs) that both interact with AU-rich sequences but have antagonistic roles. While ELAVL1 binding has been profiled in several studies, the precise in vivo binding specificity of ZFP36 has not been investigated on a global scale. We determined ZFP36 binding preferences using cross-linking and immunoprecipitation in human embyonic kidney cells and examined combinatorial regulation of AU-rich elements by ZFP36 and ELAVL1. Among the targets ZFP36 binds and negatively regulates the mRNA of genes encoding proteins necessary for immune function and cancer, and other RBPs. Using partial correlation analysis, we were able to quantify the association between ZFP36 binding sites and differential target RNA abundance from ZFP36 overexpression independent of effects from confounding features, such as 3 UTR length. We identified thousands of overlapping ZFP36 and ELAVL1 binding sites, in 1,313 genes. ZFP36 preferentially interacts with and regulates AU-rich sequences while ELAVL1 prefers predominantly U- and CU-rich sequences. RNA target specificity identified by global in vivo ZFP36-mRNA interactions were quantitatively similar to previously reported in vitro binding affinities. ZFP36 and ELAVL1 both bind an overlapping spectrum of RNA sequences, yet with differential relative preferences that dictate combinatorial regulatory potential. Our findings and methodology delineate an approach to untangle the in vivo combinatorial regulation by RNA-binding proteins.
Global target mRNA specification and regulation by the RNA-binding protein ZFP36.
Cell line, Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identification of mRNAs bound and regulated by human LIN28 proteins and molecular requirements for RNA recognition.
Cell line
View SamplesHuman LIN28A and B are RNA-binding proteins (RBPs) conserved in animals with important roles during development and stem cell reprogramming. We used Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation (PAR-CLIP) in HEK293 cells and identified a largely overlapping set of ~3,000 mRNAs at ~9,500 sites located in the 3UTR and CDS. In vitro and in vivo, LIN28 preferentially bound single-stranded RNA containing a uridine-rich element and one or more flanking guanosines, and appeared to be able to disrupt base-pairing to access these elements when embedded in predicted secondary structure. In HEK293 cells, LIN28 protein binding mildly stabilized target mRNAs and increased protein abundance. The top targets were its own mRNAs and those of other RBPs and cell-cycle regulators. Alteration of LIN28 protein levels also negatively regulated the abundance of some, but not all let-7 miRNA family members, indicating sequence-specific binding of let-7 precursors to LIN28 proteins and competition with cytoplasmic miRNA biogenesis factors.
Identification of mRNAs bound and regulated by human LIN28 proteins and molecular requirements for RNA recognition.
Cell line
View SamplesHuman LIN28A and B are RNA-binding proteins (RBPs) conserved in animals with important roles during development and stem cell reprogramming. We used Photoactivatable-Ribonucleoside-Enhanced Crosslinking and Immunoprecipitation (PAR-CLIP) in HEK293 cells and identified a largely overlapping set of ~3,000 mRNAs at ~9,500 sites located in the 3’UTR and CDS. In vitro and in vivo, LIN28 preferentially bound single-stranded RNA containing a uridine-rich element and one or more flanking guanosines, and appeared to be able to disrupt base-pairing to access these elements when embedded in predicted secondary structure. In HEK293 cells, LIN28 protein binding mildly stabilized target mRNAs and increased protein abundance. The top targets were its own mRNAs and those of other RBPs and cell-cycle regulators. Alteration of LIN28 protein levels also negatively regulated the abundance of some, but not all let-7 miRNA family members, indicating sequence-specific binding of let-7 precursors to LIN28 proteins and competition with cytoplasmic miRNA biogenesis factors. Overall design: To assess whether miRNAs are regulated by LIN28B we analyzed the miRNA levels of LIN28B overexpressing and LIN28B-depleted cells using small RNA cDNA library sequencing. The RBP LIN28B was depleted by siRNAs and the expression levels was compared to mock-transfected HEK293 cells.
Identification of mRNAs bound and regulated by human LIN28 proteins and molecular requirements for RNA recognition.
Cell line, Subject
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