Project description:Intestinal mucosal mast cells are critically involved in the development of food-induced allergic disorders. However, factors that induce differentiation of mucosal mast cells in the intestinal mucosa are largely unknown. To identify factors involved in mucosal mast cell differentiation, we compared the gene expression profiles between mucosal mast cells isolated from the small intestine and bone marrow-derived mast cells cultured in the presence of TGF-β or Notch ligand. Mucosal mast cells were isolated from the small intestine of naïve BALB/c mice by flow cytometry. Bone marrow-derived mast cells (BMMCs) were generated by culturing BALB/c bone marrow cells with murine interleukin-3 and stem cell factor for 3-4 weeks, and then cells were cultured for 6 days in the presence or absence of TGF-β or Delta-like 1 (Dll1), which is a Notch ligand. Total RNAs extracted from these cells were processed and hybridized to Affymetrix GeneChips.
Project description:Intestinal mucosal mast cells are critically involved in the development of food-induced allergic disorders. However, factors that induce differentiation of mucosal mast cells in the intestinal mucosa are largely unknown. To identify factors involved in mucosal mast cell differentiation, we compared the gene expression profiles between mucosal mast cells isolated from the small intestine and bone marrow-derived mast cells cultured in the presence of TGF-β or Notch ligand.
Project description:<p>Paired-end transcriptome sequencing was performed on a panel of breast cancer cell lines and tissues and a set of benign cell line and tissue controls. Analyses of the paired end sequences were performed and chimeric transcripts derived from gene rearrangement events were identified. Sequencing was performed on Illumina GAII and HiSeq 2000 platforms with read lengths from 40 to 100 bases.</p>
Project description:Canine mast cell tumour proliferation depends to a large extent on the activity of KIT, a tyrosine kinase receptor. Inhibitors of the KIT tyrosine kinase have recently been introduced and successfully applied as a therapeutic agent for this tumour type. However, little is known on the downstream target genes of this signalling pathway and molecular changes after inhibition. Transcriptome analysis of the canine mast cell tumour cell line C2 treated for up to 72 hours with the tyrosine kinase inhibitor masitinib identified significant changes in the expression levels of approximately 3500 genes representing 16% of the canine genome. Approximately 40% of these genes had increased mRNA expression levels including genes associated with the pro-proliferative pathways of B- and T-cell receptors, chemokine receptors, steroid hormone receptors and EPO-, RAS and MAP kinase signalling. Proteome analysis of C2 cells treated for 72 hours identified 24 proteins with changed expression levels, most of which being involved in gene transcription, e.g. EIA3, EIA4, TARDBP, protein folding, e.g. HSP90, UCHL3, PDIA3 and protection from oxidative stress, GSTT3, SELENBP1. Transcriptome and proteome analysis of neoplastic canine mast cells treated with masitinib confirmed the strong important and complex role of KIT in these cells. Approximately 16% of the total canine genome and thus the majority of the active genes were significantly transcriptionally regulated. Most of these changes were associated with reduced proliferation and metabolism of treated cells. Interestingly, several pro-proliferative pathways were up-regulated which may represent attempts of masitinib treated cells to activate alternative pro-proliferative pathways. These pathways may contain hypothetical targets for a combination therapy with masitinib to further improve its therapeutic effect. The present study aimed at identifying the transcriptional and translational responses of neoplastic canine mast cells to the tyrosine kinase inhibitor masitinib. To this end, C2 cells, a cell line with a tandem duplication in the juxtamembrane unit and thus constitutively activated KIT, were treated with masitinib and changes in the global mRNA and protein expression levels were characterized.
Project description:Mast cells, activated by antigen via the high affinity receptor for IgE (FcεRI), release an array of pro-inflammatory mediators that contribute to allergic disorders such as asthma and anaphylaxis. The KIT ligand, stem cell factor (SCF), is critical for mast cell expansion, differentiation and survival, and, under acute conditions, enhances mast cell activation. However, extended SCF exposure in vivo conversely protects against fatal antigen-mediated anaphylaxis. In investigating this dichotomy, we identified a novel mode of regulation of the mast cell activation phenotype through SCF-mediated programming. We found that mouse bone marrow-derived mast cells chronically exposed to SCF displayed a marked attenuation of FcεRI-mediated degranulation and cytokine production. The hypo-responsive phenotype was not a consequence of altered signals regulating calcium flux or protein kinase C, but of ineffective cytoskeletal reorganization, with evidence implicating a down-regulation of expression of the Src kinase Hck. Collectively, these findings demonstrate a major role for SCF in the homeostatic control of mast cell activation with potential relevance to mast cell-driven disease and the development of novel approaches for the treatment of allergic disorders. Mouse bone marrow-derived mast cells were treated with IL3, IL3+IL33, or IL3+SCF. Six replicates each.
Project description:Mast cells are indispensable for LPS-induced septic hypothermia, in which TNF-α plays an essential role to initiate sepsis. Tec family non-receptor tyrosine kinases ITK and BTK regulate mast cell-derived TNF-α in response to allergic antigen, but their role in LPS-induced TNF-α production by mast cells and related pathology is unclear. We sought to investigate the role(s) of ITK and BTK in mast cell response in septic condition. We found that the absence of ITK and BTK leads to enhanced TNF-α production by bone marrow-derived mast cells (BMMC). Itk-/-Btk-/- mast cells exhibit hyperactive preformed and LPS-induced TNF-α production, along with enhanced expression of other related genes such as NF-κB targeted genes, compared to WT cells. Bone marrow cells from 8-week old WT, Itk-/-, Btk-/- and Itk-/-Btk-/- (double knockout: DKO) C57Bl/6 mice were cultured in murine Interleukin-3/Stem cell factor (IL-3/SCF) supplemented medium for 5 weeks to derive mast cells. WT, Itk-/-, Btk-/- and DKO bone marrow-derived mast cells (BMMC) were factor starved in medium without IL-3/SCF for 12 hours, followed by treatment with PBS (control) or 100 ng/ml LPS for 1 hour. Triplicates of each group were subjected to mouse whole genome genechip microarray analysis. Replicates were randomized on different chips to avoid systematic error.
Project description:Mast cells, activated by antigen via the high affinity receptor for IgE (FcεRI), release an array of pro-inflammatory mediators that contribute to allergic disorders such as asthma and anaphylaxis. The KIT ligand, stem cell factor (SCF), is critical for mast cell expansion, differentiation and survival, and, under acute conditions, enhances mast cell activation. However, extended SCF exposure in vivo conversely protects against fatal antigen-mediated anaphylaxis. In investigating this dichotomy, we identified a novel mode of regulation of the mast cell activation phenotype through SCF-mediated programming. We found that mouse bone marrow-derived mast cells chronically exposed to SCF displayed a marked attenuation of FcεRI-mediated degranulation and cytokine production. The hypo-responsive phenotype was not a consequence of altered signals regulating calcium flux or protein kinase C, but of ineffective cytoskeletal reorganization, with evidence implicating a down-regulation of expression of the Src kinase Hck. Collectively, these findings demonstrate a major role for SCF in the homeostatic control of mast cell activation with potential relevance to mast cell-driven disease and the development of novel approaches for the treatment of allergic disorders.
Project description:Mast cells are indispensable for LPS-induced septic hypothermia, in which TNF-α plays an essential role to initiate sepsis. Tec family non-receptor tyrosine kinases ITK and BTK regulate mast cell-derived TNF-α in response to allergic antigen, but their role in LPS-induced TNF-α production by mast cells and related pathology is unclear. We sought to investigate the role(s) of ITK and BTK in mast cell response in septic condition. We found that the absence of ITK and BTK leads to enhanced TNF-α production by bone marrow-derived mast cells (BMMC). Itk-/-Btk-/- mast cells exhibit hyperactive preformed and LPS-induced TNF-α production, along with enhanced expression of other related genes such as NF-κB targeted genes, compared to WT cells.