Mus musculus
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ABSTRACT:
PROVIDER: PRJNA182169 | ENA |
REPOSITORIES: ENA
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Project description:Endotoxin/LPS tolerance is a tightly regulated phenomenon, which, during infection, prevents systemic hyper-inflammation. Here we report for the first time that morphine reversal of endotoxin tolerance resulting in persistent inflammation thus contributing to septicemia and septic shock. We further report that this regulation is mediated by LPS-induced down-regulation of microRNAs 146a and 155. However, only over-expression of miR-146a, but not miR-155 abrogates morphine mediated hyper-inflammation, while antagonizing miR-146a (but not miR-155) augments morphine mediated hyper-inflammation. Hence, miR-146a could be the potential therapeutic target for morphine-mediated abrogation of endotoxin tolerance.
2013-08-01 | GSE42506 | GEO
Project description:Endotoxin/LPS tolerance is a tightly regulated phenomenon, which, during infection, prevents systemic hyper-inflammation. Here we report for the first time that morphine reversal of endotoxin tolerance resulting in persistent inflammation thus contributing to septicemia and septic shock. We further report that this regulation is mediated by LPS-induced down-regulation of microRNAs 146a and 155. However, only over-expression of miR-146a, but not miR-155 abrogates morphine mediated hyper-inflammation, while antagonizing miR-146a (but not miR-155) augments morphine mediated hyper-inflammation. Hence, miR-146a could be the potential therapeutic target for morphine-mediated abrogation of endotoxin tolerance. All treatments done in vivo. Morphine implanted subcuteniously, LPS administered as intraperitoneal injection.
2013-08-01 | E-GEOD-42506 | biostudies-arrayexpress
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.
2009-08-21 | GSE17421 | 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:Background: Sepsis involves aberrant immune responses to infection, but the exact nature of this immune dysfunction remains poorly defined. Bacterial endotoxins like lipopolysaccharide (LPS) are potent inducers of inflammation, which has been associated with the pathophysiology of sepsis, but repeated exposure can also induce a suppressive effect known as endotoxin tolerance or cellular reprogramming. It has been proposed that endotoxin tolerance might be associated with the immunosuppressive state that was primarily observed during late-stage sepsis. However, this relationship remains poorly characterised. Here we clarify the underlying mechanisms and timing of immune dysfunction in sepsis. Methods: We defined a gene expression signature characteristic of endotoxin tolerance. Gene-set test approaches were used to correlate this signature with early sepsis, both newly and retrospectively analysing microarrays from 593 patients in 11 cohorts. Then we recruited a unique cohort of possible sepsis patients at first clinical presentation in an independent blinded controlled observational study to determine whether this signature was associated with the development of confirmed sepsis and organ dysfunction. Findings: All sepsis patients presented an expression profile strongly associated with the endotoxin tolerance signature (p < 0.01; AUC 96.1%). Importantly, this signature further differentiated between suspected sepsis patients who did, or did not, go on to develop confirmed sepsis, and predicted the development of organ dysfunction. Interpretation: Our data support an updated model of sepsis pathogenesis in which endotoxin tolerance-mediated immune dysfunction (cellular reprogramming) is present throughout the clinical course of disease and related to disease severity. Thus endotoxin tolerance might offer new insights guiding the development of new therapies and diagnostics for early sepsis. For the RNA-Seq study reported here, 73 patients were recruited with deferred consent at the time of first examination in an emergency ward based on the opinion of physicians that there was a potential for the patient's condition to develop into sepsis. These were retrospectively divided into groups based on clinical features and compared to 11 non-urgent surgical controls.
2014-11-14 | E-GEOD-63311 | biostudies-arrayexpress
Project description:Differential gene expression profile of CD4+ T cells from 10 months old Wt, miR-155-/-, miR-146a-/- and DKO mice spleens. Wt, miR-155-/-, miR-146a-/- and DKO mice were aged 10 months, CD4+ T cells were sorted from mice spleens for analyses.
2014-12-09 | E-GEOD-58372 | biostudies-arrayexpress
Project description:The innate inflammatory response must be tightly regulated to ensure effective immune protection while avoiding inflammation-related pathologies. The transcription factor NF-kB is a critical mediator of the inflammatory response, and its dysregulation has been associated with immune related malignancies. We herein show that miR-155, miR-146a and NF-kB form a regulatory network that tunes the macrophage inflammatory response in mice. We show that elevated miR-155 expression potentiates NF-kB activity in miR-146a deficient mice, thus leading to an overactive acute inflammatory response and chronic inflammation. Enforced miR-155 expression overrides miR-146a-mediated repression of NF-kB activation, thus emphasizing that miR-155 plays a dominant, downstream role in promoting inflammation. We further show that miR-155 deficient macrophages exhibit a suboptimal inflammatory response when exposed to low levels of inflammatory stimuli. Importantly, we demonstrate a temporal asymmetry between miR-155 and miR-146a expression during macrophage activation, which forms a combined positive and negative feedback network on NF-kB activity. This miRNA based regulatory network enables a robust and time-limited inflammatory response essential for functional immunity.
2017-07-18 | GSE88791 | GEO
Project description:Background: Sepsis involves aberrant immune responses to infection, but the exact nature of this immune dysfunction remains poorly defined. Bacterial endotoxins like lipopolysaccharide (LPS) are potent inducers of inflammation, which has been associated with the pathophysiology of sepsis, but repeated exposure can also induce a suppressive effect known as endotoxin tolerance or cellular reprogramming. It has been proposed that endotoxin tolerance might be associated with the immunosuppressive state that was primarily observed during late-stage sepsis. However, this relationship remains poorly characterised. Here we clarify the underlying mechanisms and timing of immune dysfunction in sepsis. Methods: We defined a gene expression signature characteristic of endotoxin tolerance. Gene-set test approaches were used to correlate this signature with early sepsis, both newly and retrospectively analysing microarrays from 593 patients in 11 cohorts. Then we recruited a unique cohort of possible sepsis patients at first clinical presentation in an independent blinded controlled observational study to determine whether this signature was associated with the development of confirmed sepsis and organ dysfunction. Findings: All sepsis patients presented an expression profile strongly associated with the endotoxin tolerance signature (p < 0.01; AUC 96.1%). Importantly, this signature further differentiated between suspected sepsis patients who did, or did not, go on to develop confirmed sepsis, and predicted the development of organ dysfunction. Interpretation: Our data support an updated model of sepsis pathogenesis in which endotoxin tolerance-mediated immune dysfunction (cellular reprogramming) is present throughout the clinical course of disease and related to disease severity. Thus endotoxin tolerance might offer new insights guiding the development of new therapies and diagnostics for early sepsis.
2014-11-14 | GSE63311 | GEO
Project description:Chronic age-dependent inflammation, or inflammaging, is a risk-factor for many disorders that emerge in aging human populations. Mechanisms underlying these aberrant immune responses are complex and remain to be elucidated. Among recently appreciated regulators of inflammaging are microRNAs; one example of which is the anti-inflammatory miR-146a, where deficient mice succumb to life-shortening chronic inflammation. In this study, we found that deletion of miR-155 in T cells significantly extends the lifespan of miR-146a-/- mice. Using single-cell RNA sequencing and flow cytometry we found that miR-155 promotes the activation of effector T cell populations, including Tfh cells, in mice aged over 15 months. This correlated with miR-155 dependent increases in germinal center B cells, autoantibody responses and serum IgG targeting tissue antigens throughout the body. Mechanistically, we found that the aerobic glycolysis genes are elevated in T cells during aging, and to even greater levels in the absence of miR-146a, and this was reduced upon deleting miR-155 in T cells. Finally, through deletion of the mitochondrial pyruvate carrier (MPC) complex in T cells, which skews metabolism towards aerobic glycolysis, we demonstrate that several of the age-dependent, activation phenotypes of miR-146a-/- T cells were recapitulated, thus revealing the sufficiency of metabolic reprogramming to influence immune cell functions during aging. Altogether, these data indicate that miRNAs play pivotal roles in regulating lifespan through T cell mediated inflammaging.
2020-01-31 | GSE138222 | GEO
Project description:Differential gene expression profile of CD4+ T cells from 10 months old Wt, miR-155-/-, miR-146a-/- and DKO mice spleens.
2014-12-09 | GSE58372 | GEO