Project description:Bacterial lipopolysaccharide(LPS) dramatically activates macrophages. So far, dozen of papers indicated that many proinflammatory molecules are transcriptionaly regulated during response. Despite of this,translational regulation is not fully elucidated especially in a comprehensive fashion. In this series, we investigated expression profiles of translation active (polysome) inactive (free mRNP) mRNAs of a typical mouse macrophage cell line, J774.1. Moreover, we also measured total cellular RNA level as a reference. Keywords: time-course
Project description:Bacterial lipopolysaccharide(LPS) dramatically activates macrophages. So far, dozen of papers indicated that many proinflammatory molecules are transcriptionaly regulated during response. Despite of this,translational regulation is not fully elucidated especially in a comprehensive fashion. In this series, we investigated expression profiles of translation active (polysome) inactive (free mRNP) mRNAs of a typical mouse macrophage cell line, J774.1. Moreover, we also measured total cellular RNA level as a reference. Experiment Overall Design: Triplicates for each time points are included.
Project description:We subjected MCF7 cells to starvation with 0.5% charcoal treated serum for 48h and then we added 17-beta estradiol (E2) at final concentration of 10 nM, profiling before and after 60 minutes of treatment the transcriptome and the translatome, coming from the polysomal pool of mRNAs after sucrose gradient separation. Comparison of translatome profile changes with corresponding transcriptome profile changes represents a way of studying translational control networks and the degree of concordance between cellular controls affecting mRNA abundance and cellular controls affecting mRNA availability to translation. It is well known that E2 is a strong transcriptional regulator, while its translational control activity is less characterized. To provide a direct experimental evaluation of E2 induced translational regulation, we compared translatome and transcriptome profiles of E2 treated cells. Keywords: polysomal profiling, translatome profiling, polysomal RNA, translational control, translational profiling, polysome profiling, post-transcriptional regulation, estradiol stimulation, estrogen receptor. The comparison between transcriptional and polysomal profiling was used for the discovery of general and mRNA-specific changes in the translation state of the serum starved MCF7 cells transcriptome in response to E2 stimulus. To identify translationally regulated mRNA molecules, gene expression signals derived from the polysomal populations were compared by microarrays analysis to those obtained from unfractionated total RNAs. Polysomal RNA and total RNA were isolated from MCF7 cells serum starved and treated with E2. Cells lysates were collected before (t = 0 min) and after (t = 60 min) E2 treatment. All experiments were run in quadruplicates.
Project description:We subjected MCF7 cells to starvation with 0.5% charcoal treated serum for 48h and then we added 17-beta estradiol (E2) at final concentration of 10 nM, profiling before and after 60 minutes of treatment the transcriptome and the translatome, coming from the polysomal pool of mRNAs after sucrose gradient separation. Comparison of translatome profile changes with corresponding transcriptome profile changes represents a way of studying translational control networks and the degree of concordance between cellular controls affecting mRNA abundance and cellular controls affecting mRNA availability to translation. It is well known that E2 is a strong transcriptional regulator, while its translational control activity is less characterized. To provide a direct experimental evaluation of E2 induced translational regulation, we compared translatome and transcriptome profiles of E2 treated cells. Keywords: polysomal profiling, translatome profiling, polysomal RNA, translational control, translational profiling, polysome profiling, post-transcriptional regulation, estradiol stimulation, estrogen receptor.
Project description:To identify transcriptionally regulated genes in primary mouse macrophages stimulated with LPS with high sensitivity, we isolated nascent RNA following metabolic labelling with 4-thiouridine during the last 35 min before cell harvest, as recently described (Dolken et al. 2008 RNA 14:1959-72). Microarray analyses of nascent RNA identified substantially more probe sets as up-regulated after 45 min of LPS stimulation than parallel analyses of total cellular RNA. In contrast, 4.5 h after stimulation, up-regulated genes in total and nascent RNA largely overlapped. This approach therefore allowed a much more sensitive detection of early changes in transcription, and the respective genes are likely to be direct targets of LPS-regulated transcription factors. Keywords: Effect of LPS stimulation; comparison of changes in expression of total versus nascent RNA; timecourse
Project description:To identify transcriptionally regulated genes in primary mouse macrophages stimulated with LPS with high sensitivity, we isolated nascent RNA following metabolic labelling with 4-thiouridine during the last 35 min before cell harvest, as recently described (Dolken et al. 2008 RNA 14:1959-72). Microarray analyses of nascent RNA identified substantially more probe sets as up-regulated after 45 min of LPS stimulation than parallel analyses of total cellular RNA. In contrast, 4.5 h after stimulation, up-regulated genes in total and nascent RNA largely overlapped. This approach therefore allowed a much more sensitive detection of early changes in transcription, and the respective genes are likely to be direct targets of LPS-regulated transcription factors. Keywords: Effect of LPS stimulation; comparison of changes in expression of total versus nascent RNA; timecourse Two completely independent experiments were performed. Macrophages were stimulated with 100 ng/ml LPS for 45 or 270 minutes. Thiouridine pulsing was done in last 35 minutes before harvest. Total RNA was isolated. Nascent RNA was subsequently purified.
Project description:To identify oligomerization dependent interactors of C-terminal binding protein 2 (CTBP2), we stably expressed CTBP2 wild type or a monomeric mutant (CTBP2 mono: CTBP2 C140Y, N144R, R147E, L156W) in Ctbp1-/-, Ctbp2-/- J774.1 cells and profiled their genome-wide interactome in LPS conditions after 3 h of stimulation. Differential profiling of CTBP2’s wild type and monomeric interactome shows oligomer-specific interactions with multiple repressors including KDM1A and the NuRD complex. Conversely, monomers retain the ability to interact with AP-1 and RNA polymerase II.
Project description:(1) We sought to characterize the genomic profiles of H3K18Ac and H3K18Cr before and after the activation of the LPS-induced inflamatory response to elucidate the role of differential acylation in the process of gene activation. We performed chromatin Immunoprecipitation followed by massively parallel sequencing (ChIP-seq) with two antibodies, anti-H3K18Ac and anti-H3K18Cr, in RAW264.7 cells +/- LPS stimulation. (2) We also sought to characterize the effect of increasing the cellular concentration of crotonyl-CoA prior to LPS-stimulation on the expression of different classes of LPS-induced genes. We performed RNA-seq on mRNA isolated from RAW264.7 cells under four conditions a) untreated and unstimulated, b) untreated and LPS stimulated, c) crotonate pre-treated and unstimulated, d) crotonate pre-treated and LPS stimulated. Sequencing was performed on the HiSeq2000 (Illumina).
Project description:Translatome analysis by sucrose gradient centrifugation of cell lysates followed by microarray profiling of the polysomal and subpolysomal RNA fractions represents a way of both studying translational control networks and better approximating the proteomic representation of cells. It is an established notion that translational control takes place essentially at the translation initiation level, therefore the variation in abundance of a given mRNA species on polysomes can be directly related to the variation in abundance of the corresponding protein. Comparison of translatome profile changes with corresponding transcriptome profile changes can provide a measure of the degree of concordance between cellular controls affecting mRNA abundance and cellular controls affecting mRNA availability to translation. To provide a direct experimental evaluation of the phenomenon, we decided to study a classical example of transcriptional reprogramming of gene expression: Epidermal Growth Factor (EGF) treatment. This stimulus triggers a well known chain of intracellular transduction events, ultimately resulting in a multifaceted phenotypic spectrum of changes with prevalent induction of cell growth and proliferation. We subjected HeLa cells to serum starvation for 12h and then we added EGF at final concentration of 1 μg/ml, profiling before and after 40 minutes of treatment the transcriptome, the translatome, coming from the polysomal pool of mRNAs after sucrose gradient separation, and also the mRNA content of the subpolysomal pool, expected not to be actively translated. Keywords: translatome profiling, polysomal profiling, polysomal RNA, translational control, translational profiling, polysome profiling, post-transcriptional regulation, EGF starvation release. The comparison between transcriptional and polysomal profiling was used for the discovery of general and mRNA-specific changes in the translation state of the serum starved HeLa cells transcriptome in response to EGF stimulus. To identify translationally regulated mRNA molecules, gene expression signals derived from the polysomal and subpolysomal RNA populations were compared by microarrays analysis to those obtained from unfractionated total RNAs. Polysomal RNA, subpolysomal RNA and total RNA were isolated from HeLa cells serum starved and treated with EGF. Cells lysates were collected before (t = 0 min) and after (t = 40 min) EGF treatment. All experiments were run in triplicates.
Project description:Regulation of gene expression at the post-transcriptional level plays an indispensable role during TGFbeta-induced EMT and metastasis. This regulation involves a transcript-selective translational regulatory pathway in which a ribonucleoprotein (mRNP) complex, consisting of heterogeneous nuclear ribonucleoprotein E1 (hnRNP E1) and eukaryotic elongation factor 1A1 (eEF1A1), binds to a 3M-bM-^@M-^Y-UTR regulatory BAT (TGFM-NM-2 activated translation) element and silences translation of Dab2 and ILEI mRNAs, two transcripts which are involved in mediating EMT. TGFbeta activates a kinase cascade terminating in the phosphorylation of hnRNP E1, by isoform-specific stimulation of protein kinase B/Akt2, inducing the release of the mRNP complex from the 3M-bM-^@M-^Y-UTR element, resulting in the reversal of translational silencing and increased expression of Dab2 and ILEI transcripts. We adopted a combinatorial approach involving polysome profiling and RIP-Chip analyses using hnRNP E1 and filtered the array data based on the regulatory mechanism of Dab2 and ILEI. This led to the identification and validation of a cohort of target mRNAs that follow the same pattern of regulation as Dab2 and ILEI. To identify potential target mRNA transcripts that are translationally regulated by hnRNP E1 in a TGF-beta-dependent manner, we adopted a combinatorial approach involving expression profiling analyses and RNA immunoprecipitation analysis (RIP-Chip). We performed a screen using: 1) total mRNA and 2) RNA isolated from monosomal (non-translating) versus polysomal (translating) fractions from TGF-beta-treated (24 h) and non-treated NMuMG cells and from the hnRNP E1 knockdown derivative (E1KD), that undergo constitutive EMT even in the absence of TGF-beta. In addition, we screened for transcripts that selectively interact with hnRNP E1 in NMuMG cells under unstimulated conditions and subsequently lose their temporal association following TGF-beta stimulation. The samples were individually hybridized to Affymetrix GeneChipM-BM-. Mouse Genome 430 2.0 arrays.