Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.5 (RNase)
 17,967 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Staphylococcus aureus is the major cause of osteomyelitis or bone infection, leading to major morbidity, often in children. Little is known about immunopathogenesis of osteomyelitis, although uncontrolled inflammation is a major clinical feature. This study investigated effects of dexamethasone, PGE(2) and T(h)2 cytokines, all potential down-regulatory mediators, on control of S. aureus-induced C-X-C (CXCL8, CXCL10) and C-C (CCL5, CCL2) chemokine gene expression and secretion from human osteoblastic MG-63 cells and primary NHOst cells. Chemokine mRNA expression and secretion were reduced 50-75% by dexamethasone, whereas PGE(2) doubled mRNA accumulation, as detected by RNase protection assay and RT-PCR, but decreased chemokine secretion 33-71% (P < 0.05). IL-10 reduced chemokine mRNA accumulation by 20-40% in MG-63 cells. IL-4 and -13 decreased CXCL8 but not CXCL10 gene expression. IL-10 and IL-13 reduced S. aureus-induced osteoblast C-X-C chemokine secretion, whereas IL-4 decreased CXCL8 secretion 2.5-fold and increased CXCL10 secretion 3-fold (all P < 0.05). In contrast, T(h)2 cytokines increased C-C chemokine secretion from MG-63 osteoblastic cells (P < 0.05), and IL-4 and IL-13 caused similar up-regulation of CCL2 secretion from primary osteoblasts. In summary, during S. aureus infection of osteoblasts, T(h)2 cytokines, dexamethasone and PGE(2) have diverse, sometime upregulatory actions on C-C and C-X-C chemokines due to both pre- and post-transcriptional effects on chemokine secretion.
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PMID:Regulation of chemokine gene expression and secretion in Staphylococcus aureus-infected osteoblasts. 1537 6

Eosinophil-derived neurotoxin (EDN) is an eosinophil granule-derived secretory protein with ribonuclease and antiviral activity. We have previously shown that EDN can induce the migration and maturation of dendritic cells (DCs). Here, we report that EDN can activate myeloid DCs by triggering the Toll-like receptor (TLR)2-myeloid differentiation factor 88 signaling pathway, thus establishing EDN as an endogenous ligand of TLR2. EDN activates TLR2 independently of TLR1 or TLR6. When mice were immunized with ovalbumin (OVA) together with EDN or with EDN-treated OVA-loaded DCs, EDN enhanced OVA-specific T helper (Th)2-biased immune responses as indicated by predominant production of OVA-specific interleukin (IL)-5, IL-6, IL-10, and IL-13, as well as higher levels of immunoglobulin (Ig)G1 than IgG2a. Based on its ability to serve as a chemoattractant and activator of DCs, as well as the capacity to enhance antigen-specific immune responses, we consider EDN to have the properties of an endogenous alarmin that alerts the adaptive immune system for preferential enhancement of antigen-specific Th2 immune responses.
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PMID:Eosinophil-derived neurotoxin acts as an alarmin to activate the TLR2-MyD88 signal pathway in dendritic cells and enhances Th2 immune responses. 1819 77

Type-2 immunity is characterised by interleukin (IL)-4, IL-5 and IL-13, eosinophilia, mucus production, IgE, and alternatively activated macrophages (AAM). However, despite the lack of neutrophil chemoattractants such as CXCL1, neutrophils, a feature of type-1 immunity, are observed in type-2 responses. Consequently, alternative mechanisms must exist to ensure that neutrophils can contribute to type-2 immune reactions without escalation of deleterious inflammation. We now demonstrate that type-2 immune-associated neutrophil infiltration is regulated by the mouse RNase A homologue, eosinophil-associated ribonuclease 11 (Ear11), which is secreted by AAM downstream of IL-25-stimulated ILC2. Transgenic overexpression of Ear11 resulted in tissue neutrophilia, whereas Ear11-deficient mice have fewer resting tissue neutrophils, whilst other type-2 immune responses are not impaired. Notably, administration of recombinant mouse Ear11 increases neutrophil motility and recruitment. Thus, Ear11 helps maintain tissue neutrophils at homoeostasis and during type-2 reactions when chemokine-producing classically activated macrophages are infrequently elicited.
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PMID:Group-2 innate lymphoid cell-dependent regulation of tissue neutrophil migration by alternatively activated macrophage-secreted Ear11. 3245 48


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