Suppression of TLR9-dependent gene expression in vivo mediated by TTAGGG motifs
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ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Dennis Klinman
PROVIDER: E-GEOD-22156 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:CpG DNA interacts with TLR9 to stimulate a broadly protective innate immune response. This study uses bioinformatic network analysis of microarray data to identify the genes and regulatory networks triggered by CpG ODN. CpG treatment induced significant gene up-regulation (p < 0.00001) in the spleen within 30 min, peaking with the activation of >500 genes at 3 hr, and declining progressively thereafter. There were reproducible changes in the pattern of gene expression over time. This was mediated by a small group of “major inducers” (IL1A, IL1B, TNF, IFNG) whose activity was modulated by several “minor inducers” (NFKB1, IL6, IL15, IL18, STAT1, STAT2). The subsequent decline in gene activation was mediated by “suppressors” (MYC, IL1RN, SOCS1, SOCS3, NFKBIA, IL10, FOS) that actively down-regulated gene expression and targeted both major and minor inducers. Thus, the regulation of TLR9 dependent gene activation involves multiple waves of stimulation mediated by a small number of “major” and “minor” inducers followed by the active inhibition of gene expression by “suppressors”. Keywords: time series design Endotoxin-free phosphorothioate ODN were synthesized at the CBER core facility (FDA, Bethesda, MD) as previously described. Mice were injected intraperitoneal (i.p.) with 400 ìg of an equimolar mixture of CpG ODNs 1555 (GCTAGACGTTAGCGT) and 1466 (TCAACGTTGA) or control ODNs 1612 (GCTAGATGTTAGCGT) and 1471 (TCAAGCTTGA). Spleens were surgically removed from mice under sterile conditions after 0.5, 1, 3, 9, 24 hr, and/or 72 hr, diced, and stored at -800 C in RNAlater (Qiagen, Valencia, CA). Data from 4 independent experiments/time point and 4-6 untreated controls were used for all statistical analyses. Reproducibility was established by comparing gene expression profiles among similarly treated mice from independent experiments in mAdb (referenced above). Expression analyses were performed using BRB ArrayTools (Biometric Research Branch, NCI). Data were background corrected, flagged values were removed, spots in which both signals were <100 were filtered out, ratios were log base 2 transformed and lowess intensity dependent normalization was used to adjust for differences in labeling intensities of the Cy3 and Cy5 dyes (Yang et al., 2002). Analysis was restricted to genes present on >70% of the arrays after filtering. The gene expression profile of all treatment groups was compared to that of the control groups.
2009-04-01 | E-GEOD-11202 | biostudies-arrayexpress
Project description:CpG DNA binds to Toll-like receptor 9 to stimulate a strong innate immune response. Despite extensive studies of TLR9 mediated signal transduction, the scope of CpG-induced changes in gene expression is incompletely understood. In particular, the prolonged effects of CpG ODN (oligodeoxynucleotide) on gene activation have not been investigated despite evidence that a single dose of CpG ODN alters immune reactivity for several weeks. This study used gene expression analysis to monitor changes in mRNA levels for 14 days, and identified the genes, pathways, functional groups and regulatory networks triggered in vivo following CpG ODN administration. Two discrete peaks of gene activation (at 3 hr and 5 days) were observed after CpG administration. Both the regulation and function of genes activated during the second peak differed from those triggered shortly after CpG administration. Initial gene up-regulation corresponded to a period when TLR9 ligation stimulated genes functionally associated with the generation of innate and adaptive immune responses (e.g. the NF-kB and B-cell receptor pathways). The second peak reflected processes associated with cell division (e.g., cell cycle and DNA replication & repair). Whereas TNF and IFNG played central roles regulating the first peak of activation, E2F1, E2F2, BRCA1, and HRAS had major impact on the networks controlling the second peak. The complex bimodal pattern of gene expression elicited by CpG ODN administration provides novel insights into the long term effects of CpG DNA on genes associated with immunity and cell proliferation. Data from 4 independent biological replicates/time point (9 time points) and 6 untreated controls were used for all statistical analyses. A reference design was used. Reference cDNA vs. sample cDNA were hybridized to same array.
2010-05-16 | E-GEOD-16465 | biostudies-arrayexpress
Project description:Bioinformatic analysis of microarray data was used to identify the regulatory patterns underlying changes in gene expression induced when RAW 264.7 macrophages were stimulated via TLR9 by CpG oligonucleotides (ODN) and/or via TLR3 by poly (I:C). While the genes activated by each ligand mediated similar functions, poly (I:C) elicited a larger and more diverse change in gene expression. Co-stimulation with both ligands accelerated gene expression and synergistically activated genes primarily associated with immune function. This is the first work to compare global changes in gene regulation triggered by distinct TLR pathways and clarify their impact on gene expression. RAW 264.7 cells were cultured for 5 days in DMEM supplemented with 10% FCS, 50 U/ml penicillin, 50 ug/ml streptomycin, and 1mM sodium pyruvate at 37C in a 5% CO2 in air incubator. Cells were washed, transferred into new flasks, and rested for 16 hr before being stimulated with 3.2 ug/ml CpG ODN and/or 32 ug/ml poly(I:C) for 4 - 12 hr. All experiments were independently repeated three times, and data from all experiments combined for analysis. Control samples included RAW 264.7 cells that were unstimulated and collected at 4 and 12 hours. All arrays used reverse transcribed mRNA from stimulted and unstimulated RAW cells as well as Universal Mouse Reference RNA purchased from Stratagene, La Holla, CA.
2009-07-21 | E-GEOD-15416 | biostudies-arrayexpress
Project description:HGF has been reported to have both positive and negative effects on carcinogenesis. Here we show that the loss of c-Met signaling in hepatocytes enhanced rather than suppressed the early stages of chemical hepatocarcinogenesis. c-Met conditional knockout mice (c-metfl/fl, AlbCre+/-; MetLivKO) treated with N-nitrosodiethylamine (DEN) developed significantly more and bigger tumors and with a shorter latency as compared with control (wt/wt, AlbCre+/-; Cre-Ctrl) mice. Accelerated tumor development was associated with increased rate of cell proliferation and prolonged activation of epidermal growth factor receptor (EGFR) signaling. MetLivKO livers treated with DEN also displayed elevated lipid peroxidation, decreased ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG), and upregulation of superoxide dismutase 1 (Sod1) and heat shock protein 70 (Hsp70), all consistent with increased oxidative stress. Likewise, gene expression profiling performed at 3 and 5 months after DEN treatment revealed upregulation of genes associated with cell proliferation and stress responses in c-Met mutant livers. The negative effects of c-Met-deficiency were reversed by chronic oral administration of anti-oxidant N-acetylcysteine (NAC). NAC blocked the EGFR activation and reduced the DEN-initiated hepatocarcinogenesis to the levels of Cre-Ctrl mice. These results argue that intact HGF/c-Met signaling is essential for maintaining normal redox homeostasis in the liver and has tumor suppressor effect(s) during the early stages of DEN-induced hepatocarcinogenesis. Keywords: compound treatment design To address a role for c-Met in liver carcinogenesis, we employed a hepatocyte specific c-Met conditional knockout mouse model generated in our laboratory. Mice received a single intraperitoneal injection of 10 µg/g body weight of N-nitrosodiethylamine (DEN) (Sigma-Aldrich, Inc., St. Louis, MO, USA) at 14 days of age. Livers were examined at 3 and 5 months after DEN injection. Expression profiling was conducted on five animals from each genotype per time point. Total RNA pooled from five wild-type B6/129 strain mouse livers was used as universal hybridization reference. All experiments were performed in duplicates following a dye-swapping design. Arrays were scanned with a GenePix 4000A scanner (Axon Instruments Ltd., Burlingame, CA) in a way to achieve optimal signal intensity at both channels with less than 1% saturated spots. After excluding the invalid features, all arrays were normalized to the 50th percentile of the median signal intensity using the mAdb data analysis suite (http://nciarray.nci.nih.gov/). Unsupervised cluster analysis was performed with the Cluster and TreeView programs (http://rana.lbl.gov/EisenSoftware.htm). The BRB ArrayTools V3.3.0 software package (Biometric Research Branch, National Cancer Institute; http://linus.nci.nih.gov/BRB-ArrayTools.html) was used for the supervised comparison. Differentially expressed genes were selected using a univariate 2-sample t-test (P<0.001) with a random variance model (15). Functional classification of the significant genes was based on the Gene Ontology (GO) annotations (www.geneontology.org).
2008-08-09 | E-GEOD-8747 | biostudies-arrayexpress
Project description:The goals of this study were to identify gene transcription changes in cells expressing activated H-RasV12 or activated versions of the ras effector domain mutants RasV12G37, RasV12S35, and RasV12C40 for the purpose of identifying common or unique transcription alterations in cells transformed by different ras signal transduction pathways. Keywords: genetic modification design HME16C mammary epithelial cells infected with pLRT control vector, or H-RasV12-, V12G37-, V12S35-, or V12C40-expressing vectors were each treated with 250ng/mL doxycycline and total RNA prepared at two separate times to give two biological replicates. Then dye swap experiments were performed with each biological replicate.
2008-08-01 | E-GEOD-8916 | biostudies-arrayexpress
Project description:The goal of this study was to compare the radiation-induced gene translation profiles generated from human tumor cell lines that are treated with radiation. Keywords: stimulus or stress design A panel of cell lines included 5 gliomas, 4 pancreatic carcinomas, 3 breast carcinomas and 2 non-small cell lung carcinomas. In addition, radiation-induced gene translation profiles were generated for 4 normal human cell lines: a skin fibroblast (BJ), 2 lung fibroblasts (MRC5, MRC9) and mammary epithelial (MEC). Specifically, cell lines were exposed to 2 Gy or sham irradiated, polysome-bound RNA was isolated 6h later and subjected to microarray analyses. Each cell line was evaluated in biological replicates.
2010-07-20 | E-GEOD-10547 | biostudies-arrayexpress
Project description:Type-I (e.g. IFN-alpha, IFN-beta) and type-II IFNs (IFN-gamma) have antiviral, antiproliferative, and immunomodulatory properties. Both types of IFN signal through the Jak/STAT pathway to elicit antiviral activity, yet IFN-gamma is thought to do so only through STAT1 homodimers while type-I IFNs activate both STAT1- and STAT2-containing complexes such as ISGF3. Here we show that ISGF3II - composed of phosphorylated STAT1, unphosphorylated STAT2, and IRF9 - also plays a role in IFN-gamma-mediated antiviral activity in humans. Using phosphorylated STAT1 as a marker for IFN signaling, western blot analysis of IFN-alpha2a treated human A549 cells revealed that pSTAT1 (Y701) levels peaked at 1h, decreased by 6h, and remained at low levels for up to 48h. Cells treated with IFN-gamma showed a biphasic pSTAT1 response with an early peak at 1-2h and a second peak at 15-24h. Gene expression microarray following IFN-gamma treatment for 24h indicated an induction of antiviral genes that are induced by ISGF3 and associated with a type-1 IFN response. Induction of these genes by autocrine type-I and type-III IFN signaling was ruled out using neutralizing antibodies to these IFNs in biological assays and by qRT-PCR. Despite the absence of autocrine IFNs, IFN-gamma treatment induced formation of ISGF3II. This novel transcription factor complex binds to ISRE promoter sequences, as shown by ChIP analysis of the PKR promoter. STAT2 and IRF9 knockdown in A549 cells reversed IFN-gamma-mediated ISRE induction and antiviral activity - implicating ISGF3II formation as a significant component of the cellular response and biological activity of IFN-gamma. Two treatments using three biological replicates each were performed using three million A549 cells. Each was seeded overnight in 10mL complete RPMI and treated. Three were treated with alpha-IFN and three treated with gamma-IFN for 24h. Control samples were left untreated.
2011-01-19 | E-GEOD-25113 | biostudies-arrayexpress
Project description:Traditional Chinese Medicine (TCM) has been used for thousands of years to treat or prevent diseases, including cancer. Good manufacturing practices (GMP) and sophisticated product analysis (PhytomicsQC) to ensure consistency are now available allowing the assessment of its utility. Polychemical Medicines, like TCM, include chemicals with distinct tissue-dependent pharmacodynamic properties that result in tissue-specific bioactivity. Determining the mode of action of these mixtures was previously unsatisfactory; however, information rich RNA microarray technologies now allow for thorough mechanistic studies about complex mixtures effects. PHY906 is a long used four herb TCM formula employed as adjuvant to relieve side effects associated with chemotherapy. Animal studies documented a decrease in global toxicity and an increase in therapeutic effectiveness of chemotherapy when PHY906 was combined. Using a systems biology approach, we studied tumor tissue to identify reasons for the enhancement of the antitumor effect of Irinotecan by PHY-906 in a well-characterized pre-clinical model; PHY-906 and Irinotecan were administered orally to female BDF-1 mice bearing subcutaneous Colon 38 tumors. We observed that 1) individually PHY-906 and Irinotecan induce distinct alterations in tumor, liver and spleen; 2) PHY-906 alone predominantly induces repression of transcription and immune-suppression in tumors; 3) these effects are reverted in the presence of Irinotecan, with prevalent induction of pro-apoptotic and pro-inflammatory pathways that may favor tumor rejection. Most importantly, PHY-906 together with Irinotecan triggers unique changes not activated by each one alone suggesting that the combination creates a unique tissue-specific response. Four groups of BDF-1 mice bearing colon 38 tumors were treated with Phosphate Buffered Saline (PBS) (n=10), PHY-906 (n=10), Irinotecan (CPT-11, Camptosar(TM)) (n=10) or the combination PHY-906 and Irinotecan (n=10). Tumor (38 samples), spleen (38 samples), and liver (35 samples) tissues were removed and frozen for total RNA isolation and subsequent microarray hybridization. There were a total of 111 samples representing 12 treated tissue groups with 8 to 10 biological replicates each. A reference sample was generated from a pool of mixed normal mouse tissue.
2011-10-21 | E-GEOD-25192 | biostudies-arrayexpress
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2009-09-14 | E-GEOD-15246 | biostudies-arrayexpress
Project description:Each array hybridization involved one male sample hybridized in competition to one female sample. For each hybridization one sample was labeled with Cy5 and the other with Cy3. Half of the male samples were labeled with Cy5 and rest with Cy3. Each hybridization was tissue-specific (i.e., hybridize male brain vs. female brain, male liver vs. female liver, etc.). A total of 10 male-female hybridizations were performed using adult brain, 7 for liver, 9 for kidney and 8 for postnatal day1 brain. One hybridization each from adult brain and liver were discarded because the hybridization intensities were far out of range.
2007-02-15 | E-MEXP-543 | biostudies-arrayexpress