Polyketide synthase-derived sphingolipids determine microbiota-mediated protection against pathogens inC. elegans
Ontology highlight
ABSTRACT:
ORGANISM(S): Caenorhabditis elegans
PROVIDER: GSE245296 | GEO | 2023/10/14
REPOSITORIES: GEO
Similar Datasets
Project description:Sphingolipids are required for diverse biological functions and are degraded by specific catabolic enzymes. However, the mechanisms that regulate sphingolipid catabolism are not known. Here we characterize a transcriptional axis that regulates sphingolipid breakdown to control resistance against bacterial infection. From an RNAi screen for transcriptional regulators of pathogen resistance in the nematode C. elegans, we identified the nuclear hormone receptor nhr-66, a ligand-gated transcription factor homologous to human hepatocyte nuclear factor 4. Tandem chromatin immunoprecipitation-sequencing (ChIP-seq) and RNA sequencing (RNA-seq) experiments revealed that NHR-66 is a transcriptional repressor, which directly targets sphingolipid catabolism genes. Transcriptional de-repression of two sphingolipid catabolic enzymes in nhr-66 loss-of-function mutants drives the breakdown of sphingolipids, which enhances host susceptibility to infection with the bacterial pathogen Pseudomonas aeruginosa. These data define transcriptional control of sphingolipid catabolism in the regulation of cellular sphingolipids, a process that is necessary for pathogen resistance.
2023-09-08 | GSE240425 | GEO
Project description:Sphingolipids are required for diverse biological functions and are degraded by specific catabolic enzymes. However, the mechanisms that regulate sphingolipid catabolism are not known. Here we characterize a transcriptional axis that regulates sphingolipid breakdown to control resistance against bacterial infection. From an RNAi screen for transcriptional regulators of pathogen resistance in the nematode C. elegans, we identified the nuclear hormone receptor nhr-66, a ligand-gated transcription factor homologous to human hepatocyte nuclear factor 4. Tandem chromatin immunoprecipitation-sequencing (ChIP-seq) and RNA sequencing (RNA-seq) experiments revealed that NHR-66 is a transcriptional repressor, which directly targets sphingolipid catabolism genes. Transcriptional de-repression of two sphingolipid catabolic enzymes in nhr-66 loss-of-function mutants drives the breakdown of sphingolipids, which enhances host susceptibility to infection with the bacterial pathogen Pseudomonas aeruginosa. These data define transcriptional control of sphingolipid catabolism in the regulation of cellular sphingolipids, a process that is necessary for pathogen resistance.
2023-09-08 | GSE240426 | GEO
Project description:Persister cells are genetically identical variants in a bacterial population that have phenotypically modified their physiology to survive environmental stress. . To better define general persistence mechanisms that can be targeted to develop anti-persistence therapeutics, we performed transcriptomics analyses of Burkholderia thailandensis enriched for persisters using three methods: flow sorting by low proton motive force, meropenem treatment, and culture aging. Although the three persister populations generally expressed divergent gene expression profiles that underscores the multi-mechanistic nature of persistence, there were several common gene pathways expressed in two or more persister populations, including polyketide and non-ribosomal peptide synthesis, Clp proteases, mobile elements, enzymes involved in the lipid metabolism, and ATP-binding cassette (ABC) transporter systems. In particular, identification of genes that encode for polyketide synthases (PKS) and fatty acid catabolism indicate that generation of secondary metabolites, natural products, and complex lipids are needed for the maintenance of the persistence state. Persisters are markedly reduced in transposon mutants of the PKS gene BTH_I2366. Furthermore, treatment of multiple bacterial pathogens with the fatty acid synthesis inhibitor, CP-640186, potentiated antibiotic efficacy against the persisters. All together, our results suggest that bacterial persisters may exhibit an outward dormant physiology, but maintain active metabolic processes that are required to maintain persistence.
2019-03-06 | GSE127838 | GEO
Project description:Disrupted interactions between host and intestinal bacteria are implicated in the development of colorectal cancer (CRC). However, the functional impacts of these inter-kingdom interactions remain poorly defined. To examine this interplay, we performed mouse and microbiota RNA-sequencing on colon tissue from germ-free (GF) and gnotobiotic ApcMin/+;Il10-/- mice associated with microbes from biofilm-positive human CRC tumor (BT) and biofilm-negative healthy (BX) tissues. The bacteria in BT mice differentially expressed >2,900 genes related to bacterial secretion, virulence and biofilms, but only affected 62 host genes. Importantly, the bacterial communities from BT mice were transmissible and carcinogenic when administered to a new GF ApcMin/+;Il10-/- cohort, maintaining a set of 13 bacterial genera. Our findings suggest complex interactions within bacterial communities affecting bacterial composition and CRC development.
2019-12-30 | GSE108156 | GEO
Project description:rs07-05_sphingolipids-cold - sphingo-1 - The cold choc response seems to be partly triggered by Sphingolipid species. To date no gene response as been associated to sphingolipid signaling pathway in plant. Our aim is to identify among the cold induced genes the ones regulated by sphingolipids and to try to define a sphingolipid pathway specific group of genes. - 7ml of 5 days-old cells suspensions were incubated in presence of different sphingolipid pathway inhibitors, 30 min to 2 hours depending in the coumpound (all were resuspended in DMSO and control were done with DMSO). Then a 30 min cold choc was applied before cells were harvested and frozen in cold nitrogen. RNA were then extracted. FB1 and DMS were from Alexis , Myr from Cayman, TSP from matreya. 6 dye-swap - treated vs untreated comparison
2012-03-27 | E-GEOD-36659 | biostudies-arrayexpress
Project description:Metabolic programs and host defense are highly integrated to ensure proper immune responses during stress. Central to these responses, mTOR regulates immune functions by sensing and integrating environmental cues, yet how these systems are coordinated at the intestinal surface remains undefined. We show that the antimicrobial peptide α-defensin is functionally sustained during nutrient deprivation due to regulation of defensin-processing enzyme MMP7 by microbiota- and host-derived factors. Unlike other antimicrobial peptides, the MMP7-α-defensin axis remains active during nutrient fluctuations, providing essential protection against enteric pathogens. Sustained Mmp7 expression requires the microbiota and is mediated by de-repression of the transcription activator Atoh1 upon attenuation of the transcriptional repressor Hes1 in intestinal epithelial cells. Hes1 levels are regulated via mTOR and controlled translationally, constituting a metabolism-translation-transcription loop. Disrupting this loop by supplying nutrients paradoxically compromises anti-bacterial defense. Together, these results uncover a regulatory circuit that couples host nutrient status to epithelial anti-microbial immunity.
2019-03-25 | GSE119568 | GEO
Project description:Pneumonia is a serious problem worldwide. We recently demonstrated that innate defense mechanisms of the lung are highly inducible against pneumococcal pneumonia. To determine the breadth of protection conferred by stimulation of lung mucosal innate immunity, and to identify cells and signaling pathways activated by this treatment, mice were treated with an aerosolized bacterial lysate, then challenged with lethal doses of bacterial and fungal pathogens. Mice were highly protected against a broad array of Gram-positive, Gram-negative, and Class A bioterror bacterial pathogens, and Aspergillus fumigatus. Protection was associated with rapid pathogen killing within the lungs, and this effect was recapitulated in vitro using a respiratory epithelial cell line. Gene expression analysis of lung tissue showed marked activation of NF-kappa-B, Type I and II interferon, and antifungal Card9-Bcl10-Malt1 pathways. Cytokines were the most strongly induced genes, but the inflammatory cytokines TNF and IL-6 were not required for protection. Lung-expressed antimicrobial peptides were also highly upregulated. Taken together, stimulated innate resistance (StIR) appears to occur through the activation of multiple host defense signaling pathways in lung epithelial cells, inducing rapid pathogen killing, and conferring broad protection against virulent bacterial and fungal pathogens. Augmentation of innate antimicrobial defenses of the lungs might have therapeutic value for protection of patients with neutropenia or impaired adaptive immunity against opportunistic pneumonia, and for defense of immunocompetent subjects against a bioterror threat or epidemic respiratory infection. Keywords: Differential expression, innate immunity, pneumonia, immunocompromised host; lung epithelium, in vitro, MLE-15 cells were treated with sham (PBS), NTHi lysate (100 ug/ml) or EF2505-III (40 ug/ml). 4 unique samples per group. Treated for 2 hours. Hybridized to Illumina Sentrix Mouse-6 v1.1 Beadhips.
2010-06-24 | E-GEOD-13685 | biostudies-arrayexpress
Project description:Pneumonia is a serious problem worldwide. We recently demonstrated that innate defense mechanisms of the lung are highly inducible against pneumococcal pneumonia. To determine the breadth of protection conferred by stimulation of lung mucosal innate immunity, and to identify cells and signaling pathways activated by this treatment, mice were treated with an aerosolized bacterial lysate, then challenged with lethal doses of bacterial and fungal pathogens. Mice were highly protected against a broad array of Gram-positive, Gram-negative, and Class A bioterror bacterial pathogens, and Aspergillus fumigatus. Protection was associated with rapid pathogen killing within the lungs, and this effect was recapitulated in vitro using a respiratory epithelial cell line. Gene expression analysis of lung tissue showed marked activation of NF-kappaB, Type I and II interferon, and antifungal Card9-Bcl10-Malt1 pathways. Cytokines were the most strongly induced genes, but the inflammatory cytokines TNF and IL-6 were not required for protection. Lung-expressed antimicrobial peptides were also highly upregulated. Taken together, stimulated innate resistance (StIR) appears to occur through the activation of multiple host defense signaling pathways in lung epithelial cells, inducing rapid pathogen killing, and conferring broad protection against virulent bacterial and fungal pathogens. Augmentation of innate antimicrobial defenses of the lungs might have therapeutic value for protection of patients with neutropenia or impaired adaptive immunity against opportunistic pneumonia, and for defense of immunocompetent subjects against a bioterror threat or epidemic respiratory infection. Keywords: differential gene expression; time course; innate immunity; pneumonia; immunocompromised host; lung epithelium Gene expression patterns in mouse lung homogenates were analyzed 2h after exposure to aerosolized PBS (Sham treatment), 2h after exposure to aerosolized NTHi lysate or 4h after exposure to aerosolized NTHi lysate. Each group consisted of six mice.
2010-06-24 | E-GEOD-13740 | biostudies-arrayexpress
Project description:We analyzed the delayed LPS-induced expression pattern in monocytes. Activation of monocytes by microbial products is an important mechanism contributing to host protection against invading pathogens. This process has to be tightly controlled to ensure that antimicrobial response does not result in fatal host tissue damage. Therefore we investigated control mechanisms during prolonged monocyte activation by bacterial endotoxin.
2015-03-06 | GSE55608 | GEO
Project description:Pneumonia is a serious problem worldwide. We recently demonstrated that innate defense mechanisms of the lung are highly inducible against pneumococcal pneumonia. To determine the breadth of protection conferred by stimulation of lung mucosal innate immunity, and to identify cells and signaling pathways activated by this treatment, mice were treated with an aerosolized bacterial lysate, then challenged with lethal doses of bacterial and fungal pathogens. Mice were highly protected against a broad array of Gram-positive, Gram-negative, and Class A bioterror bacterial pathogens, and Aspergillus fumigatus. Protection was associated with rapid pathogen killing within the lungs, and this effect was recapitulated in vitro using a respiratory epithelial cell line. Gene expression analysis of lung tissue showed marked activation of NF-kappa-B, Type I and II interferon, and antifungal Card9-Bcl10-Malt1 pathways. Cytokines were the most strongly induced genes, but the inflammatory cytokines TNF and IL-6 were not required for protection. Lung-expressed antimicrobial peptides were also highly upregulated. Taken together, stimulated innate resistance (StIR) appears to occur through the activation of multiple host defense signaling pathways in lung epithelial cells, inducing rapid pathogen killing, and conferring broad protection against virulent bacterial and fungal pathogens. Augmentation of innate antimicrobial defenses of the lungs might have therapeutic value for protection of patients with neutropenia or impaired adaptive immunity against opportunistic pneumonia, and for defense of immunocompetent subjects against a bioterror threat or epidemic respiratory infection. Keywords: Differential expression, innate immunity, pneumonia, immunocompromised host; lung epithelium, in vitro,
2008-11-21 | GSE13685 | GEO