Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.27.1 (RNase)
16,360 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We assessed changes in transcriptional activation of the inducible isoform of nitric oxide synthase (iNOS) in a model of macrophage-dependent proliferative glomerulonephritis in the rat resembling human forms of rapidly progressive nephritis. By the use of a cDNA probe derived from rat glomerular RNA and an RNase protection assay, iNOS expression was assessed at early and late stages of the disease and was correlated with the extent of macrophage infiltration. Prominent iNOS expression occurred in isolated glomeruli 24 hr after onset of immune injury when marked glomerular infiltration by macrophages also occurred. Treatment of animals with immune injury with the arachidonic acid cyclooxygenase inhibitor, indomethacin, potentiated iNOS expression. iNOS expression was short-lived; it was markedly reduced on Day 2 of injury and undetectable on Days 4 and 10, despite sustained infiltration of glomeruli by macrophages. These observations suggest that in glomerular immune injury the enhanced expression of iNOS is not sustainable possibly due to downregulatory factors generated in the course of injury.
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PMID:Changes in inducible nitric oxide synthase expression in experimental glomerulonephritis. 927 Jul 25

In the newborn, cyclooxygenase (COX)-derived products play an important role in the cerebrovascular dysfunction after ischemia-reperfusion (I/R). We examined effects of I/R on expression of COX-1 and COX-2 isoforms in large cerebral arteries of anesthetized piglets. The circle of Willis, the basilar, and the middle cerebral arteries were collected from piglets at 0.5-12 h after global ischemia (2.5-10 min, n = 50), hypoxia (n = 3), or hypercapnia (n = 2) and from time-control (n = 19) or untreated animals (n = 7). Tissues were analyzed for COX-1 and COX-2 mRNA and protein using RNase protection assay and immunoblot analysis, respectively. Ischemia increased COX-2 mRNA by 30 min, and maximal levels were reached at 2 h. Hypoxia or hypercapnia had minimal effects on COX-2 mRNA. COX-2 protein levels were also consistently elevated by 8 h after I/R. Increases in COX-2 mRNA or protein were not influenced by pretreatment with either indomethacin (5 mg/kg iv, n = 5) or nitro-L-arginine methyl ester (15 mg/kg iv, n = 7). COX-1 mRNA levels were low in time controls, and ischemic stress had no significant effect on COX-1 expression. Thus ischemic stress leads to relatively rapid, selective induction of COX-2 in cerebral arteries.
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PMID:Ischemia-reperfusion rapidly increases COX-2 expression in piglet cerebral arteries. 1048 43

The therapeutic efficacy and antiovulatory properties of non-steroidal anti-inflammatory drugs (NSAIDs) is attributed to their ability to suppress prostaglandin endoperoxide synthase (PGS) activity. Given the likely role of interleukin (IL)-1 in the inflammatory (and probably the ovulatory) process, we set out to evaluate whether the antiovulatory property of NSAIDs is attributable, in part, to the inhibition of ovarian IL-1 action. Whole ovarian dispersates from immature rats were cultured under serum-free conditions in the absence or presence of the indicated agents. At the conclusion of the culture period, total RNA was extracted and probed for transcripts corresponding to PGS-1, PGS-2, IL-1beta, IL-1 receptor antagonist (IL-1RA) or type I IL-1 receptor (IL-1R) by a solution hybridization/ribonuclease protection assay. Treatment with indomethacin was without significant effect on the early (1 h) response to IL-1beta; however, it led to complete and highly significant dose-dependent blockade of the late (48 h) response to IL-1beta as assessed in terms of PGS-2 transcripts, proteins and activity. The addition of PGE2 to cells augmented the ability of IL-1beta to upregulate PGS-2 transcripts. Moreover, the addition of PGE2 to indomethacin-treated cells all but reversed the ability of indomethacin to suppress the IL-1beta effect at both the PGS-2 transcript and protein levels. The upregulation by IL-1 of IL-1beta, IL-1R and IL-1RA transcripts was similarly inhibited by indomethacin. Taken together, these observations suggest that the anti-ovulatory property of NSAIDs may be due, in part, to blockade of the late, prostanoid-dependent component of ovarian IL-1 action.
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PMID:Non-steroidal anti-inflammatory drugs (NSAIDs) block the late, prostanoid-dependent/ceramide-independent component of ovarian IL-1 action: implications for the ovulatory process. 1061 94

Ischemia/reperfusion (I/R) results in a robust induction of cyclooxygenase (COX)-2 in the newborn brain via unknown mechanisms, but glutamate release and activation of KA receptors may be involved. We examined effects of local KA (3-300 micromol/l for 10 min) treatment on cortical COX-2 expression in anesthetized piglets using a closed cranial window. Treated and corresponding control tissue samples were collected 0.5-10 h after treatment. COX-2 mRNA and protein levels were assessed using RNase protection assay and immunohistochemistry, respectively. KA elicited reproducible dose-dependent increases in cortical COX-2 mRNA unaffected by indomethacin or N(G)-nitro-L-arginine methyl ester pretreatment. COX-2 mRNA levels were elevated at 30 min, peaked at 2 h, but remained enhanced for up to 10 h after KA. Neuronal COX-2 immunoreactivity was also enhanced compared with the control side in all cortical layers 8h after KA. In summary, activation of KA receptors may be involved in the neuronal induction of COX-2 after I/R in the newborn.
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PMID:Kainic acid rapidly induces cyclooxygenase (COX)-2 in piglet cerebral cortex. 1109 94

We previously described that recombinant interleukin-1beta (IL-1beta) induced the significant release of substance P (SP) via a cyclooxygenase (COX) pathway in primary cultured rat dorsal root ganglion (DRG) cells. In the present study, we examined the involvement of two types of phospholipase A2 (PLA2) enzymes, which lie upstream of COX in the prostanoid-generating pathway, in the IL-1beta-induced release of SP from DRG cells. The expression of type IIA secretory PLA2 (sPLA2 -IIA) mRNA was undetectable by ribonuclease protection assay in non-treated DRG cells, while in DRG cells incubated with 1 ng/mL of IL-1beta, the expression was induced in a time-dependent manner. On the other hand, type IV cytosolic PLA2 (cPLA2 ) mRNA was constitutively expressed in the non-treated DRG cells, and treatment with 1 ng/mL of IL-1beta for 3 h significantly increased the levels of cPLA2 mRNA. The IL-1beta-induced SP release was significantly inhibited by the sPLA2 inhibitor, thioetheramide phosphorylcholine (TEA-PC), and the cPLA2 inhibitor, arachidonyl trifluoromethyl ketone (AACOCF3 ). Furthermore AACOCF3 suppressed the induction of sPLA2 -IIA mRNA expression induced by IL-1beta. These observations suggested that two types of PLA2, sPLA2 -IIA and cPLA2, were involved in the IL-1beta-induced release of SP from DRG cells, and that the functional cross-talk between the two enzymes might help to control their activity in the prostanoid-generating system in DRG cells. These events might be key steps in the inflammation-induced hyperactivity in primary afferent neurons of spinal cord.
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PMID:Interleukin-1beta-induced substance P release from rat cultured primary afferent neurons driven by two phospholipase A2 enzymes: secretory type IIA and cytosolic type IV. 1195 49

Based on the controversy about the relevance of cyclooxygenase-2 (Cox-2)-derived prostanoids from the macula densa for the control of the renin system, this study aimed to determine the interrelation between Cox-2 and renin expression in the mouse kidney. In control mice renin mRNA was readily detectable whilst renocortical Cox-2 mRNA abundance was at the detection limit of the RNase protection assay and no specific signals for Cox-2 were obtained by in situ hybridization or Western blot analysis. Experimental maneuvers such as low-salt diet, treatment with loop diuretics or angiotensin I converting enzyme inhibitors clearly increased renin mRNA abundance up to sevenfold, but under none of these conditions renocortical Cox-2 mRNA levels were significantly changed. Moreover, the strong stimulation of renin expression by angiotensin I-converting enzyme inhibition was not changed by the cyclooxygenase inhibitor ibuprofen, which in turn clearly lowered tissue prostanoid content. Our data suggest a marked divergence of renin and Cox-2 expression in the kidney cortex of C57Bl/6 mice with no clear evidence for a role of Cox-2-derived prostanoids from the macula densa in the regulation of renin expression.
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PMID:Differential regulation of renin and Cox-2 expression in the renal cortex of C57Bl/6 mice. 1450 26

The anti-inflammatory effects of salicylates, originally attributed to inhibition of cyclooxygenase activity, are currently known to involve additional mechanisms. In this study we investigated the possible modulation by salicylates of NFAT-mediated transcription in lymphocytic and monocytic cell lines. RNase protection assays showed that 2-acetoxy-4-trifluoromethylbenzoic acid (triflusal) inhibited, in a dose-dependent manner, mRNA expression of several cytokine genes, most of which are NFAT-regulated and cyclosporin A (CsA)-sensitive. In Jurkat cells, the expression of IL-3, GM-CSF, TNF-alpha, TGF-beta1, IL-2, lymphotactin, MIP-1alpha, and MIP-1beta was inhibited to different extents. In THP-1 cells, inhibition of the expression of M-CSF, G-CSF, stem cell factor, IFN-gamma, TNF-alpha, TGF-beta1, lymphotoxin-beta1, MIP-1alpha, MIP-1beta, and IL-8 was observed. Sodium salicylate and aspirin only showed significant effects at 5 mM. The transcriptional activity of two genes that contain NFAT sites, a GM-CSF full promoter and a T cell-specific enhancer from the IL-3 locus, was also inhibited by salicylates. Transactivation experiments performed with several NFAT-dependent and AP-1-dependent reporter genes showed that triflusal strongly inhibited NFAT-dependent transcription at concentrations as low as 0.25 mM. Sodium salicylate and aspirin were less potent. The triflusal inhibitory effect was reversible and synergized with suboptimal doses of CsA. Experiments to address the mechanism of action of salicylates in the NFAT activation cascade disclosed a mechanism different from that of CsA, because salicylates inhibited DNA-binding and NFAT-mediated transactivation without affecting phosphorylation or subcellular localization of NFAT. In summary, these data describe a new pharmacological effect of salicylates as inhibitors of NFAT-dependent transcription.
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PMID:A new pharmacological effect of salicylates: inhibition of NFAT-dependent transcription. 1549 24

Inhalation of crystalline (CS) and amorphous silica (AS) results in human pulmonary inflammation. However, silicosis develops only following CS exposure, and the pathogenic mechanisms are poorly understood. This report describes the differential abilities of CS and AS to directly upregulate the early inflammatory mediator COX-2, the recently identified prostaglandin E (PGE) synthase and the downstream mediator PGE2 in primary human lung fibroblasts. Increased cyclooxygenase (COX)-2 gene transcription and protein production were demonstrated by ribonuclease protection assay, Western blot analysis, and immunocytochemistry. In each case the ability of AS to induce COX-2 exceeded that of CS. Similarly, downstream of COX-2, production of the antifibrotic prostaglandin PGE2 was induced in a dose-dependent fashion, but AS was significantly more potent (maximal production: CS = 4,710 pg/ml and AS = 7,651 pg/ml). These increases in COX-2 and PGE2 were preceded by induction of the PGE2 synthase protein, demonstrating the potential role of this novel molecule in silica-mediated inflammation. There was specificity of induction of prostaglandins, as PGF2alpha, but not PGD2, was induced. Using specific COX-2 inhibitors, we showed increased PG production to be dependent on the COX-2 enzyme. Furthermore, stimulation of fibroblasts was particle specific, as silica but not carbon black resulted in fibroblast activation. These results demonstrate that silica can directly stimulate human lung fibroblasts to produce key inflammatory enzymes and prostaglandins. Moreover, they suggest a mechanism to explain the differing fibrogenic potential of CS and AS. The molecules COX-2, PGE synthase, and PGE2 are identified as effectors in silicosis.
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PMID:Crystalline and amorphous silica differentially regulate the cyclooxygenase-prostaglandin pathway in pulmonary fibroblasts: implications for pulmonary fibrosis. 1566 45

Resveratrol (Res), a polyphenolic compound found largely in the skin of red grape and wine, exhibits a wide range of pharmaceutical properties and plays a role in prevention of human cardiovascular diseases [Pendurthi et al., Arterioscler. Thromb. Vasc. Biol. 19, 419-426 (1999)]. It shows a strong affinity towards protein binding and used as inhibitor for cyclooxygenase and ribonuclease reductase. The aim of this study was to examine the interaction of resveratrol with human serum albumin (HSA) in aqueous solution at physiological conditions, using a constant protein concentration (0.3 mM) and various pigment contents (microM to mM). FTIR, UV-Visible, CD, and fluorescence spectroscopic methods were used to determine the resveratrol binding mode, the binding constant and the effects of pigment complexation on protein secondary structure. Structural analysis showed that resveratrol bind non-specifically (H-bonding) via polypeptide polar groups with overall binding constant of K(Res) = 2.56 x 10(5) M(-1). The protein secondary structure, analysed by CD spectroscopy, showed no major alterations at low resveratrol concentrations (0.125 mM), whereas at high pigment content (1 mM), major increase of alpha-helix from 57% (free HSA) to 62% and a decrease of beta-sheet from 10% (free HSA) to 7% occurred in the resveratrol-HSA complexes. The results indicate a partial stabilization of protein secondary structure at high resveratrol content.
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PMID:Resveratrol binding to human serum albumin. 1705 86

Aim: Autosomal dominant polycystic kidney disease is one of the most common genetic renal diseases. Cyclooxygenase plays an important role in epithelial cell proliferation and may contribute to the mechanisms underlying cyst formation. The aim of the present study was to evaluate the role of cyclooxygenase inhibition in the cyst progression in polycystic kidney disease. Method: Pkd2WS25/- mice, a murine model which harbors a compound cis-heterozygous mutation of the Pkd2 gene were used. Cyclooxygenase expression was assessed in both human and murine kidney specimens. Pkd2WS25/- mice were treated with Sulindac (a nonselective cyclooxygenase inhibitor) or vehicle for 8 months starting at three weeks age, and then renal cyst burden was assessed by kidney weight and volume. Results: Cyclooxygenase-2 expression was up-regulated compared to control kidneys as shown by RNase protection in human polycystic kidneys and immunoblot in mouse Pkd2WS25/- kidneys. Cyclooxygenase-2 expression was up-regulated in the renal interstitium as well as focal areas of the cystic epithelium (p<0.05). Basal Cyclooxygenase-1 levels were unchanged in both immunohistochemistry and real-time PCR. Administration of Sulindac to Pkd2WS25/- mice and to control mice for 8 months resulted in reduced kidney weights and volume in cystic mice. Renal function and electrolytes were not significantly different between groups. Conclusion: Thus treatment of a murine model of polycystic kidney disease with Sulindac results in decreased kidney cyst burden. These findings provide additional implications for the use of Cyclooxygenase inhibition as treatment to slow the progression of cyst burden in patients with polycystic kidney disease.
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PMID:Nonselective Cyclooxygenase Inhibition Retards Cyst Progression in a Murine Model of Autosomal Dominant Polycystic Kidney Disease. 3066 41


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