The JAK2-STAT pathway epigenetically regulates tolerized genes during the first encounter to bacterial antigens [array]
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ABSTRACT:
PROVIDER: PRJNA668108 | ENA |
REPOSITORIES: ENA
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Project description:The JAK2-STAT pathway epigenetically regulates tolerized genes during the first encounter to bacterial antigens
| PRJNA668134 | ENA
Project description:Microbial challenges, such as widespread bacterial infection, induce endotoxin tolerance. This state of hypo-responsiveness to subsequent infections is mainly displayed by monocytes and macrophages. Endotoxin tolerance is generally acquired following a septic episode. In this study, we investigated DNA methylation changes during the acquisition of in vitro tolerance. We identified a set of TET2-mediated demethylation events that are specific to toll like receptor (TLR) 2 and 4 stimulation. Lipopolysaccharide (LPS)-specific demethylation occurs at genomic sites that have low accessibility in quiescent monocytes, concomitantly with the transcriptional activation of many inflammation-related genes, and they are enriched in binding motifs for several signal transducer and activator of transcription (STAT) family members. Indeed, STAT1, STAT3 and STAT5, elements of the JAK2 pathway, are phosphorylated in association with the acquisition of endotoxin tolerance. Inhibition of the JAK2 pathway impairs the activation of tolerized genes at the first encounter with LPS. This supports a crucial role of this pathway in determining the initial response of these genes to bacterial antigens and provides a pharmacological target to prevent exacerbated responses, allowing regulated responses upon subsequent challenges. Finally, we prove the pathological relevance of the JAK2 pathway in monocytes from patients with sepsis.
2021-11-23 | GSE159227 | GEO
Project description:Microbial challenges, such as widespread bacterial infection, induce endotoxin tolerance. This state of hypo-responsiveness to subsequent infections is mainly displayed by monocytes and macrophages. Endotoxin tolerance is generally acquired following a septic episode. In this study, we investigated DNA methylation changes during the acquisition of in vitro tolerance. We identified a set of TET2-mediated demethylation events that are specific to toll like receptor (TLR) 2 and 4 stimulation. Lipopolysaccharide (LPS)-specific demethylation occurs at genomic sites that have low accessibility in quiescent monocytes, concomitantly with the transcriptional activation of many inflammation-related genes, and they are enriched in binding motifs for several signal transducer and activator of transcription (STAT) family members. Indeed, STAT1, STAT3 and STAT5, elements of the JAK2 pathway, are phosphorylated in association with the acquisition of endotoxin tolerance. Inhibition of the JAK2 pathway impairs the activation of tolerized genes at the first encounter with LPS. This supports a crucial role of this pathway in determining the initial response of these genes to bacterial antigens and provides a pharmacological target to prevent exacerbated responses, allowing regulated responses upon subsequent challenges. Finally, we prove the pathological relevance of the JAK2 pathway in monocytes from patients with sepsis.
2021-11-23 | GSE159249 | GEO
Project description:The JAK2-STAT pathway epigenetically regulates tolerized genes during the first encounter to bacterial antigens [RNA-seq]
| PRJNA668138 | ENA
Project description:This SuperSeries is composed of the SubSeries listed below.
2021-11-23 | GSE159250 | GEO
Project description:Microbial challenges, such as widespread bacterial infection in sepsis, induce endotoxin tolerance, a state of hyporesponsiveness to subsequent infections. The participation of DNA methylation in this process is poorly known. In this study, we perform integrated analysis of DNA methylation and transcriptional changes following in vitro exposure to gram-negative bacterial lipopolysaccharide, together with analysis of ex vivo monocytes from septic patients. We identify TET2-mediated demethylation and transcriptional activation of inflammation-related genes that is specific to toll-like receptor stimulation. Changes also involve phosphorylation of STAT1, STAT3 and STAT5, elements of the JAK2 pathway. JAK2 pathway inhibition impairs the activation of tolerized genes on the first encounter with lipopolysaccharide. We then confirm the implication of the JAK2-STAT pathway in the aberrant DNA methylome of patients with sepsis caused by gram-negative bacteria. Finally, JAK2 inhibition in monocytes partially recapitulates the expression changes produced in the immunosuppressive cellular state acquired by monocytes from gram-negative sepsis, as described by single cell-RNA-sequencing. Our study evidences both the crucial role the JAK2-STAT pathway in epigenetic regulation and initial response of the tolerized genes to gram-negative bacterial endotoxins and provides a pharmacological target to prevent exacerbated responses.
| S-EPMC8635809 | biostudies-literature
Project description:A heterogeneous genetic subtype of B-cell precursor acute lymphoblastic leukemia is driven by constitutive kinase-activation, including patients with JAK2 fusions. In our study, we model the impact of a novel JAK2 fusion protein on hematopoietic development in human induced pluripotent stem cells (hiPSCs). We insert the RUNX1-JAK2 fusion into one endogenous RUNX1 allele through employing in trans paired nicking genome editing. Tagging of the fusion with a degron facilitates protein depletion using the heterobifunctional compound dTAG-13. Throughout in vitro hematopoietic differentiation, the expression of RUNX1-JAK2 is driven by endogenous RUNX1 regulatory elements at physiological levels. Functional analysis reveals that RUNX1-JAK2 knock-in cell lines yield fewer hematopoietic progenitors, due to RUNX1 haploinsufficiency. Nevertheless, these progenitors further differen-tiate toward myeloid lineages to a similar extent as wild-type cells. The expression of the RUNX1-JAK2 fusion protein only elicits subtle effects on myeloid differentiation, and is unable to transform early hematopoietic progenitors. However, phosphoprotein and transcriptome analyses reveal that RUNX1-JAK2 constitutively activates JAK-STAT signaling in differentiating hiPSCs and at the same time upregulates MYC targets—confirming the interaction between these pathways. This proof-of-principle study indicates that conditional expression of oncogenic fusion proteins in combination with hematopoietic differentiation of hiPSCs may be applicable to leukemia-relevant disease modeling.
2021-07-08 | GSE159261 | GEO
Project description:The genetics of classical Hodgkin lymphoma (cHL) is poorly understood. The finding of a JAK2-involving t(4;9)(q21;p24) in one case of cHL prompted us to characterize this translocation on a molecular level and to determine the prevalence of JAK2 rearrangements in cHL. We showed that the t(4;9)(q21;p24) leads to a novel SEC31A-JAK2 fusion. Screening of 131 cHL cases identified one additional case with SEC31A-JAK2 and two additional cases with rearrangements involving JAK2. We demonstrated that SEC31A-JAK2 is oncogenic in vitro and acts as a constitutively activated tyrosine kinase that is sensitive to JAK inhibitors. In vivo, SEC31A-JAK2 was found to induce a T-lymphoblastic lymphoma or myeloid hyperplasia in a murine bone marrow transplant model. Altogether, we identified SEC31A-JAK2 as a first aberration characteristic for cHL and provide evidence that JAK2 rearrangements occur in a minority of cHL cases. Given the proven oncogenic potential of this novel fusion, our studies provide new insights into the pathogenesis of cHL and indicate that in at least some cases, constitutive activation of the JAK-STAT pathway is caused by JAK2 rearrangements. The finding that SEC31A-JAK2 responds to JAK inhibitors indicates that patients with cHL and JAK2 rearrangements may benefit from targeted therapies. Genomic profiling of primary and secondary transplanted mice expressing SEC31A-JAK2 with myeloid hyperplasia and T-lymphoblastic lymphoma Individual sample against a normal control
2010-07-08 | E-GEOD-22404 | biostudies-arrayexpress
Project description:We used expression profiling, SNP arrays, and mutational profiling to investigate a well-characterized cohort of MPN patients. MPN patients with homozygous JAK2V617F mutations were characterized by a distinctive transcriptional profile. Notably, a transcriptional signature consistent with activated JAK2 signaling is seen in all MPN patients regardless of clinical phenotype or mutational status. In addition, the activated JAK2 signature was present in patients with somatic CALR mutations. Conversely, we identified a gene expression signature of CALR mutations; this signature was significantly enriched in JAK2-mutant MPN patients consistent with a shared mechanism of transformation by JAK2 and CALR mutations. We also identified a transcriptional signature of TET2 mutations in MPN patent samples. Our data indicate that MPN patients, regardless of diagnosis or JAK mutational status are characterized by a distinct gene expression signature with upregulation of JAK-STAT target genes, demonstrating the central importance of the JAK-STAT pathway in MPN pathogenesis. [HEL cell lines] We have performed gene expression profiling in the JAK2V617F homozygous mutant HEL cell line following treatment with 2 independent shRNAs targeting JAK2 or 2 different control shRNAs
2014-06-03 | E-GEOD-54645 | biostudies-arrayexpress
Project description:We used expression profiling, SNP arrays, and mutational profiling to investigate a well-characterized cohort of MPN patients. MPN patients with homozygous JAK2V617F mutations were characterized by a distinctive transcriptional profile. Notably, a transcriptional signature consistent with activated JAK2 signaling is seen in all MPN patients regardless of clinical phenotype or mutational status. In addition, the activated JAK2 signature was present in patients with somatic CALR mutations. Conversely, we identified a gene expression signature of CALR mutations; this signature was significantly enriched in JAK2-mutant MPN patients consistent with a shared mechanism of transformation by JAK2 and CALR mutations. We also identified a transcriptional signature of TET2 mutations in MPN patent samples. Our data indicate that MPN patients, regardless of diagnosis or JAK mutational status are characterized by a distinct gene expression signature with upregulation of JAK-STAT target genes, demonstrating the central importance of the JAK-STAT pathway in MPN pathogenesis. [MPN patients] We have performed microarray gene expression analysis in 93 patients with MPNs (28 PV, 47 ET, 18 MF) and 11 age-matched normal donors.
2014-06-03 | E-GEOD-54644 | biostudies-arrayexpress