Arachidonic acid targets pneumococcal fatty acid homeostasis
Ontology highlight
ABSTRACT:
ORGANISM(S): Streptococcus pneumoniae D39
PROVIDER: GSE93102 | GEO | 2018/05/23
REPOSITORIES: GEO
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Project description:Essential fatty acids (FA) are not only energy-rich molecules; they are also an important component of the membrane bilayer and recently have been implicated in induction of fatty acid synthase (FAS) and other genes. Using gene chip analysis, we have found that arachidonic acid (AA), an omega-6 fatty acid, induced 11 genes that are regulated by NFkappaB. We verified gene induction by omega-6 fatty acids including COX2, IKBA, NFKB, GMCSF, IL1B, CXCL1, TNFA, IL6, LTA, IL8, PPARG, and ICAM1 using qRTPCR. PGE2 synthesis was increased within 5min of addition of AA. Analysis of upstream signal transduction showed that within 5min of FA addition, phophatidylinositol 3-kinase (PI3K) was significantly activated followed by activation of Akt at 30min. ERK1 and 2, p38, and SAPK/JNK were not phosphorylated after omega-6 FA addition. Thirty minutes after FA addition, we found a significant 3-fold increase in translocation of NFkappaB transcription factor to the nucleus. Addition of non-steroidal anti-inflammatory drug (NSAID) caused a decrease in cox-2 protein synthesis, PGE2 synthesis as well as inhibition of PI3K activation. We have previously shown that AA induced proliferation is also blocked (P<0.001) by PI3K inhibitor LY294002. LY294002 also significantly inhibited the AA induced gene expression of COX2, IL1B, GMCSF, and ICAM1. Taken together, the data suggests that AA via conversion to PGE2 plays an important role in stimulation of growth related genes and proliferation via PI3K signaling and NFkappaB translocation to the nucleus.
2007-07-03 | E-GEOD-3737 | biostudies-arrayexpress
Project description:Previous data indicated tha AA and OA modify global DNA methylation. This study analyzes the impact of these fatty acids on expression as a complement to array-based DNA methylation data. In this dataset, we include the expression data obtained from THP-1 monocyte stimulated with 1, 10 or 100uM AA or OA for 24h.
2014-04-27 | GSE57076 | GEO
Project description:Essential fatty acids (FA) are not only energy-rich molecules; they are also an important component of the membrane bilayer and recently have been implicated in induction of fatty acid synthase (FAS) and other genes. Using gene chip analysis, we have found that arachidonic acid (AA), an omega-6 fatty acid, induced 11 genes that are regulated by NFkappaB. We verified gene induction by omega-6 fatty acids including COX2, IKBA, NFKB, GMCSF, IL1B, CXCL1, TNFA, IL6, LTA, IL8, PPARG, and ICAM1 using qRTPCR. PGE2 synthesis was increased within 5min of addition of AA. Analysis of upstream signal transduction showed that within 5min of FA addition, phophatidylinositol 3-kinase (PI3K) was significantly activated followed by activation of Akt at 30min. ERK1 and 2, p38, and SAPK/JNK were not phosphorylated after omega-6 FA addition. Thirty minutes after FA addition, we found a significant 3-fold increase in translocation of NFkappaB transcription factor to the nucleus. Addition of non-steroidal anti-inflammatory drug (NSAID) caused a decrease in cox-2 protein synthesis, PGE2 synthesis as well as inhibition of PI3K activation. We have previously shown that AA induced proliferation is also blocked (P<0.001) by PI3K inhibitor LY294002. LY294002 also significantly inhibited the AA induced gene expression of COX2, IL1B, GMCSF, and ICAM1. Taken together, the data suggests that AA via conversion to PGE2 plays an important role in stimulation of growth related genes and proliferation via PI3K signaling and NFkappaB translocation to the nucleus. Keywords: Time course of Prostate Cancer Activation by Arachidonic Acid
2006-01-01 | GSE3737 | GEO
Project description:Previous data indicated tha AA and OA modify global DNA methylation. This study analyzes the impact of these fatty acids on expression as a complement to array-based DNA methylation data. In this dataset, we include the expression data obtained from THP-1 monocyte stimulated with 1, 10 or 100uM AA or OA for 24h. RNA extracted from the same cells used for array-based DNA methylation analysis (see corresponding data in published article) was used to produce expression data by Affymetrix Human Exon 1.0 ST v2 Array
2014-04-27 | E-GEOD-57076 | biostudies-arrayexpress
Project description:The interaction of clinically relevant microorganisms is the focus of various studies, e.g. the interaction between the pathogenic yeast, Candida albicans, and the bacterium, Pseudomonas aeruginosa and these interactions can alter the outcome of infection, growth dynamics of each species and antimicrobial resistance of pathogens. During infection, both C. albicans and P. aeruginosa can elicit the release arachidonic acid (AA) from host cells membranes through the action of phospholipases. This polyunsaturated fatty acid can be transformed into immune-modulating compounds, termed eicosanoids, by both host-derived and microbial-derived enzymatic reactions. In its free form, AA can affect the growth of both C. albicans and P. aeruginosa, inhibiting the morphogenesis of C. albicans as well as reducing resistance towards antifungal agents. However, the mechanism of this is unknown. Previous studies on the effect of polyunsaturated fatty acids have indicated a possible alteration in plasma membrane organisation and permeability. Our group aimed to address how AA affects C. albicans in both single species biofilms, as well as in polymicrobial biofilms with P. aeruginosa. RNAseq was performed on single and polymicrobial biofilms in the presence and absence of a sub-inhibitory (100 µM) concentration of AA. Differential expression was determined between C. albicans single species biofilms in the presence and absence of AA. Secondly, the influence of co-incubation of C. albicans with P. aeruginosa in the absence of AA was evaluated to identify novel facets of interaction not previously identified, and to establish a baseline to determine the effect of AA on C. albicans in polymicrobial biofilms. Lastly, the effect of AA on C. albicans in polymicrobial biofilms was determined through comparison with polymicrobial biofilms in the absence of AA. This study provides a comprehensive analysis of the effect of AA and both co-incubation of C. albicans with P. aeruginosa focused on the transcriptome.
2021-01-31 | GSE136726 | GEO
Project description:Free fatty acids hold dual roles during infection, serving to modulate the host immune response while also functioning directly as antimicrobials. Of particular importance are the long chain polyunsaturated fatty acids, which are not commonly found in bacterial organisms, that have been proposed to have antibacterial roles. Arachidonic acid (AA) is a highly abundant long chain polyunsaturated fatty acid and we examined its effect upon Streptococcus pneumoniae. Here, we observed that in a murine model of S. pneumoniae infection the concentration of AA significantly increases in the blood. The impact of AA stress upon the pathogen was then assessed by a combination of biochemical, biophysical and microbiological assays. In vitro bacterial growth and intra-macrophage survival assays revealed that AA has detrimental effects on pneumococcal fitness. Subsequent analyses demonstrated that AA exerts antimicrobial activity via insertion into the pneumococcal membrane, although this did not increase the susceptibility of the bacterium to antibiotic, oxidative or metal ion stress. Transcriptomic profiling showed that AA treatment also resulted in a dramatic down-regulation of the genes involved in fatty acid biosynthesis, in addition to impacts on other metabolic processes, such as carbon-source utilization. Hence, these data reveal that AA has two distinct mechanisms of perturbing the pneumococcal membrane composition. Collectively, this work provides a molecular basis for the antimicrobial contribution of AA to combat pneumococcal infections.
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Project description:Progression and relapse-free survival of ovarian carcinoma are associated with the abundance of immunosuppressed CD163highCD206high tumor-associated macrophages (TAMs) and high levels of polyunsaturated fatty acids (PUFAs), in particular arachidonic acid (AA), in the tumor microenvironment. In the present study, we have investigated whether both associations are functionally linked. Methods: The effect of PUFAs on cytokine-mediated pro-inflammatory signal transduction was studied in primary monocyte-derived macrophages (MDMs) by transcriptomics, bioinformatics, phosphoprotein analysis of signal transduction proteins and MS-based proteomics of lipid rafts. Results: Pathway analysis of transcriptional profiles revealed that high CD163 and CD206/MRC1 expression in TAMs is strongly associated with an inhibition of cytokine-triggered signal transduction. This is mirrored by an impairment of the transcriptional response to interferon-beta (IFNbeta), IFNgamma and IL-6 in monocyte-derived macrophages (MDMs) by AA. This AA-mediated inhibition of pro-inflammatory signaling is caused by dysfunctions of the cognate receptors, as indicated by the inhibition by PUFAs of JAK1, JAK2, STAT1 and STAT3 phosphorylation, with the strongest inhibitory effects exerted by AA and its non-metabolizable analog ETYA. AA/ETYA treatment of MDMs results in altered composition of lipid rafts, including reduced amounts of the interferon receptor IFNAR1, STAT1 and other immune-regulatory proteins. The AA-mediated inhibition of IFN-triggered STAT1 phosphorylation was reversed by water-soluble cholesterol, known to prevent the perturbation of lipid raft structure by PUFAs. Conclusion: Our data suggest that AA, and to a lesser degree other PUFAs, impair pro-inflammatory signaling in macrophages, at least in part by altering the structure of lipid rafts, and thereby contribute to the reeducation of tumor-associated macrophages. Our findings also suggest that the pharmacologic restoration of lipid raft functions in TAM may be a promising strategy for the development of new therapeutic approaches.
2022-08-25 | PXD028434 | Pride
Project description:Arachidonic acid (AA) is a polyunsaturated fatty acid present at high concentrations in the ovarian cancer (OC) microenvironment and is associated with poor clinical outcome. In the present study, we elucidate a potential link between AA and pro-tumorigenic macrophage polarization. Methods: AA-triggered signal transduction was studied in primary monocyte-derived macrophages (MDMs) by phosphoproteomics, transcriptional profiling, measurement of intracellular Ca2+ accumulation and reactive oxygen species production in conjunction with bioinformatic analyses. Functional effects were investigated by actin filament staining, quantification of macropinocytosis and analysis of extracellular vesicle release. Results: We identified the ASK1 - p38 (MAPK13/14) axis as a central constituent of signal transduction pathways triggered by non-metabolized AA. This pathway was induced by the Ca2+-triggered activation of calmodulin kinase II, and to a minor extent by ROS generation in a subset of donors. Activated p38 in turn was linked to a transcriptional stress response associated with a poor relapse-free survival. Consistent with the phosphorylation of the p38 substrate HSP27 and the (de)phosphorylation of multiple regulators of Rho family GTPases, AA impaired actin filament organization and inhibited actin-driven macropinocytosis. AA also affected the phosphorylation of proteins regulating vesicle biogenesis, and consistently, AA enhanced the release of tetraspanin-containing exosomes. Finally, we identified phospholipase A2 Group 2A (PLA2G2A) as the clinically most relevant enzyme producing extracellular AA, providing further potentially theranostic options. Conclusion: Our results suggest that AA contributes to an unfavorable clinical outcome of OC by promoting the pro-tumorigenic phenotype of tumor-associated macrophages. Besides critical AA-regulated signal transduction proteins identified in the present study, PLA2G2A might represent a potential prognostic tool and therapeutic target to interfere with OC progression.
2020-10-05 | PXD021038 | Pride
Project description:We identify arachidonic acid (AA), as a direct proliferation promoter of intestinal epithelial cells, facilitating small intestinal regeneration. In the transcriptomes, it shows that AA treatment upregulated proliferation-related genes including Wnt signaling target genes, while downregulated differentiation-related genes including enterocyte, goblet cell, Paneth cell, enteroendocrine cell, and tuft cell markers. Additionally, AA could also upregulate stem cell-associated genes which have been highly expressed three days after 12Gy IR injury (e.g. Clu, Lamc2, Anxa1, Areg, and Ly6d). The study shows that AA treatment can be considered a potential therapy for irradiation injury repair and tissue regeneration.
2020-07-27 | GSE146871 | GEO
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