LPS-induced gene expression in mouse small intestinal epithelial cells
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE23755 | GEO | 2010/08/29
SECONDARY ACCESSION(S): PRJNA130745
REPOSITORIES: GEO
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Project description:Intestinal epithelial cells express the lipopolysaccharide (LPS) receptor Toll-like receptor (TLR4) and are responsive to LPS stimulation. Following LPS exposure, epithelial cells, similar to myeloid cells such as macrophages, acquire a state of tolerance. Innate immune tolerance is characterized by a lack of expression of proinflammatory genes in response to repeated stimulation. Tolerant epithelial cells, however, exhibit sustained expression of a distinct set of genes encoding for proteins involved in metabolism and homeostasis. This study comparatively analyzes the gene expression profile 6 hours after LPS stimulation (acute response) versus 6 hours LPS followed by 90 hours incubation in the absence of LPS (tolerant response). We used microarrays to detail the global program of gene expression under unstimulated (control), LPS stimulated (6 hours), and tolerant (96 hours) conditions. Three biological replicates each from naive cells, 6 hour LPS-stimulated cells, and 6 hour LPS-stimulated plus 90 hour LPS-free medium-incubated cells were examined and compared.
2010-08-29 | E-GEOD-23755 | biostudies-arrayexpress
Project description:To investigate the plasticity of Lipolysaccharide (LPS) tolerance, we employed microarray profiling to analyse the gene expression profile in macrophage. Four macrophage populations were induced; Untreated macrophages (Control group), Acute response to LPS (LPS activation group), LPS tolerance (T – Tolerant group) and recovered (R = recovered macrophage group) Using transcriptional analysis we demonstrate that recovery from LPS tolerance (R – Recovery), as defined by cytokine gene expression, is associated with a global change in the transcriptional profile of macrophage. This data confirms that LPS tolerance is a transient state which results in induction of novel hybrid macrophage activation state with a unique transcriptional signature. Bone marrow derived macrophages were polarised into three activation states; Acute response to LPS (A), LPS tolerant (T) and recovered (R). Gene expression was measured at 4 hours post stimulation with LPS. Three independent experiments were performed to measure gene expression changes between each macrophage group.
2013-12-06 | E-GEOD-47783 | biostudies-arrayexpress
Project description:Exposure of human monocytes to lipopolysaccharide (LPS) or other pathogen-associated molecular pattern (PAMPs) induces a temporary insensitivity to subsequent LPS challenges, a cellular state called endotoxin tolerance (ET). The tolerant state of monocytes is accompanied by cell surface and other glycoprotein expression changes induced by the activation of Toll-like receptors (TLRs). In this study, we aimed to characterize the cellular state of human monocytes stimulated with Gram-positive Staphylococcus aureus and TLR2 ligands. We analyzed gene expression changes induced by S. aureus after 2 and 24 hours by amplicon sequencing (RNA-AmpliSeq) and compared the pro-inflammatory response after 2 hours of stimulation to the to the response in re-stimulation experiments after the first stimulus. In parallel, glycoprotein expression changes in human monocytes after 24 hours of S. aureus stimulation were analyzed by proteomics and compared to stimulation experiments with TLR2 ligands Malp-2 and Pam3Cys and TLR4 ligand LPS. The results demonstrate that monocytes stimulated with S. aureus and TLR ligands entered the tolerant cell state after activation. Compared to TLR agonist mediated activation and tolerization of monocytes, glycoprotein expression changes induced by S. aureus stimulation revealed significant differences in receptor expression profiles. We report a glycoprotein expression profile characteristic for PAMP and S. aureus tolerized human monocytes. Finally, we analyzed peripheral blood monocytes of patients with S. aureus bloodstream infection for inflammatory responses in vitro and for their glycoprotein expression profiles. RNA-AmpliSeq data from patient-derived monocytes demonstrated that the cells were pro-inflammatory responsive to S. aureus stimulation and expressed higher level of CD44 mRNA, while other markers of the tolerant cell state were not detected.
2023-05-10 | PXD036036 | Pride
Project description:The inflammatory response initiated by microbial products signaling through Toll-like receptors (TLRs) of the innate immune system is essential for host defense against infection. Because inflammation can be harmful to host tissues, the innate response is highly regulated. Negative regulation of TLR4, the receptor for bacterial lipopolysaccharide (LPS), results in LPS tolerance, defined as hyporesponsiveness to repeated stimulation with LPS. LPS tolerance is thought to protect the host from excessive inflammation by turning off TLR4 signal, which then shuts down TLR-induced genes. However, TLR signaling induces hundreds of genes with very different functions. We reasoned that genes with different functions should have different requirements for regulation. Specifically, genes encoding proinflammatory mediators should be transiently inactivated to limit tissue damage, while genes encoding antimicrobial effectors, which directly target pathogens, should remain inducible in tolerant cells to protect the host from infection. Using an in vitro system of LPS tolerance in macrophages, here we show that TLR-induced genes may indeed be divided into two distinct categories based on their functions and regulatory requirements. Further, we show these distinct groups are regulated by gene-specific, and not signal-specific mechanisms. Experiment Overall Design: We examined gene expression using affymetrix genechips in 3 groups of murine bone-marrow derived macrophages: Naive (untreated), Naive stimulated with LPS, and Tolerant stimulated with LPS. Two biological replicates were performed for each group.
2008-06-15 | E-GEOD-7348 | biostudies-arrayexpress
Project description:Among the multiple mechanisms that control the intensity and duration of macrophage activation, the development of a state of refractoriness to a second stimulation in cells treated with LPS has long been recognized. Release of inhibitory cytokines and alterations in intracellular signaling pathways may be involved in the development of LPS tolerance. Although a number of molecules have been implicated, a detailed picture of the molecular changes in LPS tolerance is still missing. We have used a genome-wide gene expression analysis approach to (i) define which fraction of LPS target genes are subject to tolerance induction and (ii) identify genes that are expressed at high levels in tolerant macrophages. Our data show that in LPS tolerant macrophages the vast majority of LPS-induced gene expression is abrogated. The extent of tolerance induction varies for individual genes, and a small subset appears to be excepted. Compared to other negative control mechanisms of macrophages, e.g. IL-10-induced deactivation, LPS-tolerance inhibits a much wider range of transcriptional targets. Some previously described negative regulators of TLR-signaling (e.g. IRAK-M) were confirmed as expressed at higher levels in LPS-tolerant macrophages. In addition, we discuss other potential players in LPS tolerance identified in this group of genes. Keywords: pre and restimulation with LPS, tolerance induction
2007-08-10 | GSE8621 | GEO
Project description:MicroRNAs regulated by lipopolysaccharide (LPS) target genes that contribute to the inflammatory phenotype. Here we showed that the protein kinase Akt1, which is activated by LPS, positively regulated miRNAs let-7e, miR-181c but negatively regulated miR-155 and miR-125b. In silico analyses and transfection studies revealed that let-7e repressed Toll-like receptor 4 (TLR4) whereas miR-155 repressed SOCS1, two proteins critical for LPS-driven TLR signalling, which regulate endotoxin sensitivity and tolerance. As a result, Akt1-/- macrophages exhibited increased responsiveness to LPS in culture and Akt1-/- mice did not develop endotoxin tolerance in vivo. Overexpression of let-7e and suppression of miR-155 in Akt1-/- macrophages restored sensitivity and tolerance to LPS in culture and in animals. These results indicate that Akt1 regulates the response of macrophages to LPS by controlling miRNA expression. The data deposited here contain the entire analysis of miRNA profile of Akt1+/+ and Akt1-/- thioglycollate elicited peritoneal macrophages following stimulation with LPS for 3 hours in culture. Thioglycollate elicited macrophages were cultured in complete DMEM medium, stimulated with LPS for 3 hours and RNA was extracted. Samples were analyzed using Taq-man PCR miRNA arrays (Dana Farber microarray Facility).
2009-08-21 | E-GEOD-17421 | biostudies-arrayexpress
Project description:The inflammatory response initiated by microbial products signaling through Toll-like receptors (TLRs) of the innate immune system is essential for host defense against infection. Because inflammation can be harmful to host tissues, the innate response is highly regulated. Negative regulation of TLR4, the receptor for bacterial lipopolysaccharide (LPS), results in LPS tolerance, defined as hyporesponsiveness to repeated stimulation with LPS. LPS tolerance is thought to protect the host from excessive inflammation by turning off TLR4 signal, which then shuts down TLR-induced genes. However, TLR signaling induces hundreds of genes with very different functions. We reasoned that genes with different functions should have different requirements for regulation. Specifically, genes encoding proinflammatory mediators should be transiently inactivated to limit tissue damage, while genes encoding antimicrobial effectors, which directly target pathogens, should remain inducible in tolerant cells to protect the host from infection. Using an in vitro system of LPS tolerance in macrophages, here we show that TLR-induced genes may indeed be divided into two distinct categories based on their functions and regulatory requirements. Further, we show these distinct groups are regulated by gene-specific, and not signal-specific mechanisms. Keywords: Treatment Comparison
2007-04-22 | GSE7348 | GEO
Project description:Macrophages generate mitochondrial reactive oxygen and electrophilic species (mtROS, mtRES) as antimicrobials during Toll-like receptor (TLR)-dependent inflammatory responses. Whether mitochondrial stress caused by these molecules impacts macrophage function is unknown. Here, we demonstrate that both pharmacologically- and lipopolysaccharide (LPS)-driven mitochondrial stress in macrophages triggers a stress response called mitohormesis. LPS-driven mitohormetic stress adaptations occur as macrophages transition from an LPS-responsive to LPS-tolerant state where stimulus-induced proinflammatory gene transcription is impaired, suggesting tolerance is a product of mitohormesis. Indeed, like LPS, hydroxyestrogen-triggered mitohormesis suppresses mitochondrial oxidative metabolism and acetyl-CoA production needed for histone acetylation and proinflammatory gene transcription, and is sufficient to enforce an LPS-tolerant state. Thus, mtROS and mtRES are TLR-dependent signaling molecules that trigger mitohormesis as a negative feedback mechanism to restrain inflammation via tolerance. Moreover, bypassing TLR signaling and pharmacologically triggering mitohormesis represents a novel anti-inflammatory strategy that co-opts this stress response to impair epigenetic support of proinflammatory gene transcription by mitochondria.
2021-04-04 | GSE169729 | GEO
Project description:Macrophages generate mitochondrial reactive oxygen and electrophilic species (mtROS, mtRES) as antimicrobials during Toll-like receptor (TLR)-dependent inflammatory responses. Whether mitochondrial stress caused by these molecules impacts macrophage function is unknown. Here, we demonstrate that both pharmacologically- and lipopolysaccharide (LPS)-driven mitochondrial stress in macrophages triggers a stress response called mitohormesis. LPS-driven mitohormetic stress adaptations occur as macrophages transition from an LPS-responsive to LPS-tolerant state where stimulus-induced proinflammatory gene transcription is impaired, suggesting tolerance is a product of mitohormesis. Indeed, like LPS, hydroxyestrogen-triggered mitohormesis suppresses mitochondrial oxidative metabolism and acetyl-CoA production needed for histone acetylation and proinflammatory gene transcription, and is sufficient to enforce an LPS-tolerant state. Thus, mtROS and mtRES are TLR-dependent signaling molecules that trigger mitohormesis as a negative feedback mechanism to restrain inflammation via tolerance. Moreover, bypassing TLR signaling and pharmacologically triggering mitohormesis represents a novel anti-inflammatory strategy that co-opts this stress response to impair epigenetic support of proinflammatory gene transcription by mitochondria.
2021-04-04 | GSE169727 | GEO
Project description:Macrophages generate mitochondrial reactive oxygen and electrophilic species (mtROS, mtRES) as antimicrobials during Toll-like receptor (TLR)-dependent inflammatory responses. Whether mitochondrial stress caused by these molecules impacts macrophage function is unknown. Here, we demonstrate that both pharmacologically- and lipopolysaccharide (LPS)-driven mitochondrial stress in macrophages triggers a stress response called mitohormesis. LPS-driven mitohormetic stress adaptations occur as macrophages transition from an LPS-responsive to LPS-tolerant state where stimulus-induced proinflammatory gene transcription is impaired, suggesting tolerance is a product of mitohormesis. Indeed, like LPS, hydroxyestrogen-triggered mitohormesis suppresses mitochondrial oxidative metabolism and acetyl-CoA production needed for histone acetylation and proinflammatory gene transcription, and is sufficient to enforce an LPS-tolerant state. Thus, mtROS and mtRES are TLR-dependent signaling molecules that trigger mitohormesis as a negative feedback mechanism to restrain inflammation via tolerance. Moreover, bypassing TLR signaling and pharmacologically triggering mitohormesis represents a novel anti-inflammatory strategy that co-opts this stress response to impair epigenetic support of proinflammatory gene transcription by mitochondria.
2021-04-04 | GSE169730 | GEO