Project description:Background: Cysteinyl leukotrienes (cysLTs) are important mediators of innate immune responsiveness and chronic inflammatory diseases. CysLTs acting through cysteinyl leukotriene receptors may influence the migration and activity of cells such as eosinophils, monocytes and dendritic cells. Objective: To determine the gene expression signature of human monocytes in response to cysLTs and to elucidate the signaling pathways involved in monocyte activation. Methods: Gene expression was analyzed using oligonucleotide microarrays. Responsiveness to cysLTs was assessed by real-time PCR, calcium flux, kinase activation and chemotaxis assays. Results: Cysteinyl leukotriene type I receptor (CysLTR1) transcript 1 is predominantly expressed in human monocytes and cysLTs signal through CysLTR1 in these cells. Several immediate-early genes, including early growth response (Egr) -2, 3, FosB, activating transcription factor 3 and nuclear receptor subfamily 4 were significantly induced by LTD4. This effect was mediated by CysLTR1 coupled to Gαi/o, activation of phospholipase C, and inositol-1,4,5-triphosphate (IP3) and store operated calcium channels. LTD4 induced p38 MAP kinase phosphorylation, a pathway also involved in the regulation of immediate-early genes expression in monocytes. LTD4 stimulated monocyte chemotactic activity that was fully blocked by a selective CysLTR1 inhibitor MK571 and pertussis toxin, suggesting that CysLTR1 coupled to Gαi/o is a dominant functional pathway in human monocytes. Conclusion: Our data show that cysLTs acting through CysLTR1 can significantly influence the activation and migration of human monocytes and that these effects can be fully inhibited by CysLTR1 antagonists. Clinical implications: Antileukotriene therapies are likely to significantly block the proinflammatory functions of human monocytes. Experiment Overall Design: 4 control sample, 4 LTD4 stimulated samples
Project description:Background: Cysteinyl leukotrienes (cysLTs) are important mediators of innate immune responsiveness and chronic inflammatory diseases. CysLTs acting through cysteinyl leukotriene receptors may influence the migration and activity of cells such as eosinophils, monocytes and dendritic cells. Objective: To determine the gene expression signature of human monocytes in response to cysLTs and to elucidate the signaling pathways involved in monocyte activation. Methods: Gene expression was analyzed using oligonucleotide microarrays. Responsiveness to cysLTs was assessed by real-time PCR, calcium flux, kinase activation and chemotaxis assays. Results: Cysteinyl leukotriene type I receptor (CysLTR1) transcript 1 is predominantly expressed in human monocytes and cysLTs signal through CysLTR1 in these cells. Several immediate-early genes, including early growth response (Egr) -2, 3, FosB, activating transcription factor 3 and nuclear receptor subfamily 4 were significantly induced by LTD4. This effect was mediated by CysLTR1 coupled to Gαi/o, activation of phospholipase C, and inositol-1,4,5-triphosphate (IP3) and store operated calcium channels. LTD4 induced p38 MAP kinase phosphorylation, a pathway also involved in the regulation of immediate-early genes expression in monocytes. LTD4 stimulated monocyte chemotactic activity that was fully blocked by a selective CysLTR1 inhibitor MK571 and pertussis toxin, suggesting that CysLTR1 coupled to Gαi/o is a dominant functional pathway in human monocytes. Conclusion: Our data show that cysLTs acting through CysLTR1 can significantly influence the activation and migration of human monocytes and that these effects can be fully inhibited by CysLTR1 antagonists. Clinical implications: Antileukotriene therapies are likely to significantly block the proinflammatory functions of human monocytes. Keywords: monocytes stimulated with LTD4
Project description:Human umbilical vein endothelial cells (HUVEC) or the human macrophage cell line, Mono-Mac-6, treated with Leukotriene D4 for 1 hour
Project description:Uveal melanoma (UM) is an ocular cancer, with propensity for lethal liver metastases. When metastatic UM (MUM) occurs, as few as 8% of patients survive beyond two years. Efficacious treatments for MUM are urgently needed. 1,4-dihydroxy quininib, a cysteinyl leukotriene receptor 1 (CysLT1) antagonist, alters UM cancer hallmarks in vitro, ex vivo and in vivo. Here, we investigated the 1,4-dihydroxy quininib mechanism of action and its translational potential in MUM.