Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.2.3.23 (GAS)
 957 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

LPS is a potent stimulator of monocytes, inducing many of their functions. Although the details of how LPS exerts such functions remain largely unknown, transcription factors such as nuclear factor-kappaB, nuclear factor-IL-6, and activator protein-1 have been shown to be involved in this process. However, to date it has been thought that no known STAT molecule plays a role in the activation of monocytes by LPS. In this study we examined whether some known STAT molecule is stimulated by LPS, based on the finding that a GAS motif sequence is conserved in the promoter regions of human, mouse, and rat cyclo-oxygenase-2 (COX-2) genes. Consequently, LPS induced activation of STAT5 in human monocytes, and this STAT5 activation occurred in an indirect way via granulocyte-macrophage CSF (GM-CSF) secreted by LPS-stimulated monocytes. Expression of COX-2 protein was partially reduced by treatment of anti-human GM-CSF Ab. Activation of STAT5 was inhibited by either IL-10 or dexamethasone (Dex), but not by aspirin. IL-10 blocked activation of STAT5 indirectly by suppressing GM-CSF production, while Dex inhibited this activation both directly and indirectly. Taken together, these results suggest that in addition to other transcription factors, STAT5 plays an important role in activation of monocytes by LPS, and that STAT5 is another target for IL-10 and Dex to inhibit COX-2 expression in activated monocytes.
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PMID:Activation of STAT5 by lipopolysaccharide through granulocyte-macrophage colony-stimulating factor production in human monocytes. 955 19

Myeloid cells from non-obese diabetic (NOD) mouse and human type 1 diabetic (T1D) patients overexpress granulocyte-macrophage colony stimulation factor (GM-CSF). This overproduction prolongs the activation of signal transduction and activator of transcription 5 (STAT5) proteins, involved in GM-CSF-induced control of myeloid cell gene expression. We found that GM-CSF can regulate the binding of STAT5 on the promoter of its own gene, Csf2, within regions previously identified as sites of chromatin epigenetic modification important to the regulation of GM-CSF during myeloid differentiation and inflammation. We found multiple sequence polymorphisms within NOD mouse chromosome 11 Idd4.3 diabetes susceptibility region that alter STAT5 GAS binding sequences within the Csf2 promoter. STAT5 binding at these sites in vivo is increased significantly in GM-CSF-stimulated-bone marrow cells and in unactivated, high GM-CSF-producing macrophages from NOD mice as compared to non-autoimmune C57BL/6 mouse myeloid cells. Thus, GM-CSF overproduction by NOD myeloid cells may be perpetuating a positive epigenetic regulatory feedback on its own gene expression through its induction of STAT5 binding to its promoter. These findings suggest that aberrant STAT5 binding at epigenetic regulatory sites may contribute directly to immunopathology through cytokine-induced gene expression dysregulation that can derail myeloid differentiation and increase inflammatory responsiveness.
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PMID:GM-CSF induces STAT5 binding at epigenetic regulatory sites within the Csf2 promoter of non-obese diabetic (NOD) mouse myeloid cells. 1894 91