Project description:Although the JAK/STAT pathway regulates numerous processes in vertebrates and invertebrates through modulating transcription, its functionally-relevant transcriptional targets remain largely unknown. With one jak and one stat (stat92E), Drosophila provides a powerful system for finding new JAK/STAT target genes. Genome-wide expression profiling on eye discs in which Stat92E is hyperactivated, revealed 584 differentially-regulated genes, including known targets domeless, socs36E and wingless. Other differentially-regulated genes (chinmo, lama, Mo25, Imp-L2, Serrate, Delta) were validated and may represent new Stat92E targets. Genetic experiments revealed that Stat92E cell-autonomously represses Serrate, which encodes a Notch ligand. Loss of Stat92E led to de-repression of Serrate in the dorsal eye, resulting in ectopic Notch signaling and aberrant eye growth there. Thus, our micro-array documents a new Stat92E target gene and a previously-unidentified inhibitory action of Stat92E on Notch signaling. These data suggest that this study will be a useful resource for the identification of additional Stat92E targets. Identification of the JAK/STAT pathway target genes in the Drosophila eye disc Keywords: Genotype comparison Gene expression profiles from five biological replicates of eye discs with yw (control) and GMR-upd (overexpressing JAK/STAT ligand unpaired) were compared using genome wide mRNA expression profiling by Affymetrix genechip arrays (Drosophila 2.0) and key targets were validated by clonal analysis, in situ hybridization, immunohistochemical staining and quantitative real-time PCR.
Project description:Although the JAK/STAT pathway regulates numerous processes in vertebrates and invertebrates through modulating transcription, its functionally-relevant transcriptional targets remain largely unknown. With one jak and one stat (stat92E), Drosophila provides a powerful system for finding new JAK/STAT target genes. Genome-wide expression profiling on eye discs in which Stat92E is hyperactivated, revealed 584 differentially-regulated genes, including known targets domeless, socs36E and wingless. Other differentially-regulated genes (chinmo, lama, Mo25, Imp-L2, Serrate, Delta) were validated and may represent new Stat92E targets. Genetic experiments revealed that Stat92E cell-autonomously represses Serrate, which encodes a Notch ligand. Loss of Stat92E led to de-repression of Serrate in the dorsal eye, resulting in ectopic Notch signaling and aberrant eye growth there. Thus, our micro-array documents a new Stat92E target gene and a previously-unidentified inhibitory action of Stat92E on Notch signaling. These data suggest that this study will be a useful resource for the identification of additional Stat92E targets. Identification of the JAK/STAT pathway target genes in the Drosophila eye disc Keywords: Genotype comparison
Project description:Long-term consumption of fatty foods is associated with obesity, macrophage activation and inflammation, metabolic imbalance, and a reduced lifespan. We took advantage of Drosophila genetics to investigate the role of macrophages and the pathway(s) that govern their response to dietary stress. Flies fed a lipid-rich diet presented with increased fat storage, systemic JAK-STAT activation, reduced insulin sensitivity and hyperglycaemia, and a shorter lifespan. Drosophila macrophages scavenged lipids and produced the type 1 cytokine upd3, in a scavenger-receptor (croquemort) and JNK-dependent manner. Genetic depletion of macrophages, or macrophage-specific silencing of upd3 decreased JAK-STAT activation and rescued insulin sensitivity and the lifespan of Drosophila, but did not decrease fat storage. NF-M-NM-:B signalling made no contribution to the phenotype observed. These results identify an evolutionarily conserved M-bM-^@M-^Xscavenger receptor-JNK-Type 1 cytokineM-bM-^@M-^Y cassette in macrophages, which controls glucose metabolism and reduces lifespan in Drosophila maintained on a lipid-rich diet via activation of the JAK-STAT pathway Long-term consumption of fatty foods is associated with obesity, macrophage activation and inflammation, metabolic imbalance, and a reduced lifespan. We took advantage of Drosophila genetics to investigate the role of macrophages and the pathway(s) that govern their response to dietary stress. Flies fed a lipid-rich diet presented with increased fat storage, systemic JAK-STAT activation, reduced insulin sensitivity and hyperglycaemia, and a shorter lifespan. Drosophila macrophages scavenged lipids and produced the type 1 cytokine upd3, in a scavenger-receptor (croquemort) and JNK-dependent manner. Genetic depletion of macrophages, or macrophage-specific silencing of upd3 decreased JAK-STAT activation and rescued insulin sensitivity and the lifespan of Drosophila, but did not decrease fat storage. NF-M-NM-:B signalling made no contribution to the phenotype observed. These results identify an evolutionarily conserved M-bM-^@M-^Xscavenger receptor-JNK-Type 1 cytokineM-bM-^@M-^Y cassette in macrophages, which controls glucose metabolism and reduces lifespan in Drosophila maintained on a lipid-rich diet via activation of the JAK-STAT pathway 5 biological samples were FACS-sorted from different batches of Drosophila melanogaster males after 30 days on 15% lipid enriched diet (n=5) and control diet (n=5)
Project description:The JAK/STAT pathway is an essential signalling cascade required for multiple processes during both development and for adult homeostasis. A key question in understanding this pathway is how it is regulated in different cell contexts. Here we have examined how endocytic processing contributes to signalling by the single cytokine receptor, Domeless, in Drosophila melanogaster cells. We identify an evolutionarily conserved di-Leu motif that is required for Domeless internalisation and show that endocytosis is required for activation of a subset of Domeless targets. Our data indicate that endocytosis both qualitatively and quantitatively regulates Domeless signalling. STAT92E, the single STAT transcription factor in Drosophila, appears to be the target of endocytic regulation and our studies show that phosphorylation of STAT92E on Tyr704, while necessary, is not always sufficient for target transcription. Finally, we identify a conserved residue, Thr702, which is essential for Tyr704 phosphorylation. Taken together, our findings identify previously unknown aspects of JAK/STAT pathway regulation likely to play key roles in the spatial and temporal regulation of signalling in vivo.
Project description:Long-term consumption of fatty foods is associated with obesity, macrophage activation and inflammation, metabolic imbalance, and a reduced lifespan. We took advantage of Drosophila genetics to investigate the role of macrophages and the pathway(s) that govern their response to dietary stress. Flies fed a lipid-rich diet presented with increased fat storage, systemic JAK-STAT activation, reduced insulin sensitivity and hyperglycaemia, and a shorter lifespan. Drosophila macrophages scavenged lipids and produced the type 1 cytokine upd3, in a scavenger-receptor (croquemort) and JNK-dependent manner. Genetic depletion of macrophages, or macrophage-specific silencing of upd3 decreased JAK-STAT activation and rescued insulin sensitivity and the lifespan of Drosophila, but did not decrease fat storage. NF-κB signalling made no contribution to the phenotype observed. These results identify an evolutionarily conserved ‘scavenger receptor-JNK-Type 1 cytokine’ cassette in macrophages, which controls glucose metabolism and reduces lifespan in Drosophila maintained on a lipid-rich diet via activation of the JAK-STAT pathway Long-term consumption of fatty foods is associated with obesity, macrophage activation and inflammation, metabolic imbalance, and a reduced lifespan. We took advantage of Drosophila genetics to investigate the role of macrophages and the pathway(s) that govern their response to dietary stress. Flies fed a lipid-rich diet presented with increased fat storage, systemic JAK-STAT activation, reduced insulin sensitivity and hyperglycaemia, and a shorter lifespan. Drosophila macrophages scavenged lipids and produced the type 1 cytokine upd3, in a scavenger-receptor (croquemort) and JNK-dependent manner. Genetic depletion of macrophages, or macrophage-specific silencing of upd3 decreased JAK-STAT activation and rescued insulin sensitivity and the lifespan of Drosophila, but did not decrease fat storage. NF-κB signalling made no contribution to the phenotype observed. These results identify an evolutionarily conserved ‘scavenger receptor-JNK-Type 1 cytokine’ cassette in macrophages, which controls glucose metabolism and reduces lifespan in Drosophila maintained on a lipid-rich diet via activation of the JAK-STAT pathway
Project description:JAK/STAT pathway plays important roles in controlling Drosophila intestinal homeostasis and regulating the ISC proliferation and differentiation. However,the downstream targets of its transcription factor-STAT92E remain largely unknown.To further identify the regualtory mechanisms of the JAK/STAT pathway in controlling intestinal homeostasis,we performed the ChIP-Seq assay with mouse raised STAT92E antibody using JAK/STAT signaling highly activated adult intestines.Through the ChIP assay, we have identified over 1000 significant peaks (p<0.01) around the putative targets.The well-characterized JAK/STAT downstream targets including Domeless,Socs36E,STAT92E and chinmo were identified in our ChIP assay,indicating that our experiment is workable to identify novel JAK/STAT downstream targets in adult intestines.This work will provide insights into our understanding of regulatory mechanisms of JAK/STAT signaling during Drosophila intestinal development. Identify the ChIP peaks of STAT92E antibody using JAK/STAT signaling highly actived Drosophila adult intestines, compared with input libaray as the control
Project description:JAK/STAT pathway plays important roles in controlling Drosophila intestinal homeostasis and regulating the ISC proliferation and differentiation. However,the downstream targets of its transcription factor-STAT92E remain largely unknown.To further identify the regualtory mechanisms of the JAK/STAT pathway in controlling intestinal homeostasis,we performed the ChIP-Seq assay with mouse raised STAT92E antibody using JAK/STAT signaling highly activated adult intestines.Through the ChIP assay, we have identified over 1000 significant peaks (p<0.01) around the putative targets.The well-characterized JAK/STAT downstream targets including Domeless,Socs36E,STAT92E and chinmo were identified in our ChIP assay,indicating that our experiment is workable to identify novel JAK/STAT downstream targets in adult intestines.This work will provide insights into our understanding of regulatory mechanisms of JAK/STAT signaling during Drosophila intestinal development.
Project description:The consitutive activation of the JAK/STAT signalling cascade is reponsible for the majority of meyoproliferative disorders in humans, a disease that is also conserved in Drosophila. A gain-of-function mutation in the Drosophila JAK kinase leads to blood cell (haemocyte) overproliferation which eventually is manifested as black melanotic tumors. Haemocyte-like Drosophila Kc167 cells were used to identify downstream target genes of the JAK/STAT pathway which may be responsible for tumour generation and progression. Experiment Overall Design: Kc167 cells were activated with the principal JAK/STAT pathway ligand Unpaired (UPD) in a time course manner. To this end, for each transcript profiling condition and time point, biological duplicates were activated with UPD or Mock conditioned media for 30 min, and total RNA was extracted 2, 4 or 10h after initial addition of conditioned media. 12 samples were used for hybridization to the arrays.
Project description:The consitutive activation of the JAK/STAT signalling cascade is reponsible for the majority of meyoproliferative disorders in humans, a disease that is also conserved in Drosophila. A gain-of-function mutation in the Drosophila JAK kinase leads to blood cell (haemocyte) overproliferation which eventually is manifested as black melanotic tumors. Haemocyte-like Drosophila Kc167 cells were used to identify downstream target genes of the JAK/STAT pathway which may be responsible for tumour generation and progression.