The nuclear hormone receptor NHR-86 controls anti-pathogen responses in C. elegans
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ABSTRACT:
ORGANISM(S): Caenorhabditis elegans
PROVIDER: GSE117724 | GEO | 2019/01/09
REPOSITORIES: GEO
Similar Datasets
Project description:Nuclear hormone receptors (NHRs) are ligand-gated transcription factors that control adaptive host responses following recognition of specific endogenous or exogenous ligands. Although NHRs have expanded dramatically in C. elegans compared to other metazoans, the biological function of only a few of these genes has been characterized in detail. Here, we demonstrate that an NHR can activate an anti-pathogen transcriptional program. Using genetic epistasis experiments, transcriptome profiling analyses and chromatin immunoprecipitation-sequencing, we show that, in the presence of an immunostimulatory small molecule, NHR-86 binds to the promoters of immune effectors to activate their transcription. NHR-86 is not required for resistance to the bacterial pathogen Pseudomonas aeruginosa at baseline, but activation of NHR-86 by this compound drives a transcriptional program that provides protection against this pathogen. Interestingly, NHR-86 targets immune effectors whose basal regulation requires the canonical p38 MAPK PMK-1 immune pathway. However, NHR-86 functions independently of PMK-1 and modulates the transcription of these infection response genes directly. These findings characterize a new transcriptional regulator in C. elegans that can induce a protective host response towards a bacterial pathogen.
| S-EPMC6358101 | biostudies-literature
Project description:Germline-encoded pattern recognition receptors (e.g. Toll-like receptors) play key roles in innate immune activation. However, some metazoans, such as C. elegans, do not have canonical mechanisms of pattern recognition, yet they are able to mount anti-pathogen immune defenses. Here, we demonstrate that a nuclear hormone receptor (NHR), a ligand-gated transcription factor, functions in immune activation and pathogen defense. NHRs have expanded dramatically in C. elegans compared to other metazoans. Because NHRs often function redundantly, it has been challenging experimentally to characterize the biology of individual NHRs. Here, we use genetic epistasis experiments, transcriptome profiling analyses and chromatin immunoprecipitation to show NHR-86 is sufficient to activate protective immune defenses against the bacterial pathogen Pseudomonas aeruginosa. Interestingly, NHR-86 drives the transcription of immune effectors whose basal regulation requires the canonical p38 MAPK PMK-1 immune pathway. However, NHR-86 functions independently of PMK-1 and directly induces the transcription of infection response genes in a manner that confers protection from bacterial infection. Importantly, we found that nhr-86 does control immune gene expression and is necessary for host defense against a different pathogen, Enterococcus faecalis. Our findings characterize an ancient role of an NHR in innate immunity, and suggest that the expansion of the NHR protein family in C. elegans has been fueled in part by the need to activate immune defenses in response to pathogen attack.
2019-01-09 | GSE117719 | GEO
Project description:Germline-encoded pattern recognition receptors (e.g. Toll-like receptors) play key roles in innate immune activation. However, some metazoans, such as C. elegans, do not have canonical mechanisms of pattern recognition, yet they are able to mount anti-pathogen immune defenses. Here, we demonstrate that a nuclear hormone receptor (NHR), a ligand-gated transcription factor, functions in immune activation and pathogen defense. NHRs have expanded dramatically in C. elegans compared to other metazoans. Because NHRs often function redundantly, it has been challenging experimentally to characterize the biology of individual NHRs. Here, we use genetic epistasis experiments, transcriptome profiling analyses and chromatin immunoprecipitation to show NHR-86 is sufficient to activate protective immune defenses against the bacterial pathogen Pseudomonas aeruginosa. Interestingly, NHR-86 drives the transcription of immune effectors whose basal regulation requires the canonical p38 MAPK PMK-1 immune pathway. However, NHR-86 functions independently of PMK-1 and directly induces the transcription of infection response genes in a manner that confers protection from bacterial infection. Importantly, we found that nhr-86 does control immune gene expression and is necessary for host defense against a different pathogen, Enterococcus faecalis. Our findings characterize an ancient role of an NHR in innate immunity, and suggest that the expansion of the NHR protein family in C. elegans has been fueled in part by the need to activate immune defenses in response to pathogen attack.
2019-01-09 | GSE117700 | GEO
Project description:The nuclear hormone receptor NHR-86 controls anti-pathogen responses in C. elegans
| PRJNA492466 | ENA
Project description:The nuclear hormone receptor NHR-86 controls anti-pathogen responses in C. elegans [RNA-seq]
| PRJNA482977 | ENA
Project description:The nuclear hormone receptor NHR-86 controls anti-pathogen responses in C. elegans [ChIP-seq]
| PRJNA492468 | ENA
Project description:Mammalian nuclear hormone receptors (NHRs), such as liver X receptor, farnesoid X receptor, and peroxisome proliferator-activated receptors (PPARs), precisely control energy metabolism. Consequently, these receptors are important targets for the treatment of metabolic diseases, including diabetes and obesity. A thorough understanding of NHR fat regulatory networks has been limited, however, by a lack of genetically tractable experimental systems. Here we show that deletion of the Caenorhabditis elegans NHR gene nhr-49 yielded worms with elevated fat content and shortened life span. Employing a quantitative RT-PCR screen, we found that nhr-49 influenced the expression of 13 genes involved in energy metabolism. Indeed, nhr-49 served as a key regulator of fat usage, modulating pathways that control the consumption of fat and maintain a normal balance of fatty acid saturation. We found that the two phenotypes of the nhr-49 knockout were linked to distinct pathways and were separable: The high-fat phenotype was due to reduced expression of enzymes in fatty acid beta-oxidation, and the shortened adult life span resulted from impaired expression of a stearoyl-CoA desaturase. Despite its sequence relationship with the mammalian hepatocyte nuclear factor 4 receptor, the biological activities of nhr-49 were most similar to those of the mammalian PPARs, implying an evolutionarily conserved role for NHRs in modulating fat consumption and composition. Our findings in C. elegans provide novel insights into how NHR regulatory networks are coordinated to govern fat metabolism.
| S-EPMC547972 | biostudies-literature
Project description:Pattern recognition of bacterial products by host receptors is essential for pathogen sensing in many metazoans. Caenorhabditis elegans, however, do not utilize canonical pattern recognition receptors to activate innate immunity toward bacterial pathogens. Whether other mechanisms evolved in nematodes to directly sense pathogens is not known. Here, we characterize the first bacterial pattern recognition receptor and its natural ligand in C. elegans. We show that the C. elegans nuclear hormone receptor NHR-86/HNF4 senses phenazine-1-carboxamide (PCN), a metabolite produced by pathogenic strains of Pseudomonas aeruginosa, to activate protective anti-pathogen defenses in the intestine. PCN binds to the ligand binding domain of NHR-86/HNF4, a ligand-gated transcription factor, which engages a transcriptional program in intestinal epithelial cells that promotes metabolism of toxic phenazines to provide protection against P. aeruginosa. These data de-orphan a nuclear hormone receptor and demonstrate that sensing a metabolite signal of bacterial virulence allows nematodes to detect pathogens in its environment that are poised to cause disease.
2023-02-07 | GSE202258 | GEO
Project description:Nuclear hormone receptors respond to small molecules such as retinoids or steroids and regulate development. Signaling in the conserved p38/PMK-1 MAP kinase pathway regulates innate immunity. In this study, we show that the Caenorhabditis elegans nuclear receptor DAF-12 negatively regulates the defense against pathogens via the downstream let-7 family of microRNAs, which directly target SKN-1, a gene downstream of PMK-1. These findings identify nuclear hormone receptors as components of innate immunity that crosstalk with the p38/PMK-1 MAP kinase pathway.
| S-EPMC3749966 | biostudies-literature
Project description:Nuclear hormone receptors (NHRs) are transcription factors that regulate numerous physiological and developmental processes and represent important drug targets. NHR-49, an ortholog of Hepatocyte Nuclear Factor 4 (HNF4), has emerged as a key regulator of lipid metabolism and life span in the nematode worm Caenorhabditis elegans. However, many aspects of NHR-49 function remain poorly understood, including whether and how it regulates individual sets of target genes and whether its activity is modulated by a ligand. A recent study identified three gain-of-function (gof) missense mutations in nhr-49 (nhr-49(et7), nhr-49(et8), and nhr-49(et13), respectively). These substitutions all affect the ligand-binding domain (LBD), which is critical for ligand binding and protein interactions. Thus, these alleles provide an opportunity to test how three specific residues contribute to NHR-49 dependent gene regulation. We used computational and molecular methods to delineate how these mutations alter NHR-49 activity. We find that despite originating from a screen favoring the activation of specific NHR-49 targets, all three gof alleles cause broad upregulation of NHR-49 regulated genes. Interestingly, nhr-49(et7) and nhr-49(et8) exclusively affect nhr-49 dependent activation, whereas the nhr-49(et13) surprisingly affects both nhr-49 mediated activation and repression, implicating the affected residue as dually important. We also observed phenotypic non-equivalence of these alleles, as they unexpectedly caused a long, short, and normal life span, respectively. Mechanistically, the gof substitutions altered neither protein interactions with the repressive partner NHR-66 and the coactivator MDT-15 nor the subcellular localization or expression of NHR-49. However, in silico structural modeling revealed that NHR-49 likely interacts with small molecule ligands and that the missense mutations might alter ligand binding, providing a possible explanation for increased NHR-49 activity. In sum, our findings indicate that the three nhr-49 gof alleles are non-equivalent, and highlight the conserved V411 residue affected by et13 as critical for gene activation and repression alike.
| S-EPMC5019492 | biostudies-literature