Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Brief episodes of ischemia can render an organ resistant to subsequent severe ischemia. This 'ischemic preconditioning' is ascribed to various mechanisms, including oxidative stress. We investigated whether preconditioning exists on an endothelial level. Human umbilical vein endothelial cells (HUVECs) were transiently confronted with oxidative stress (1 mM H(2)O(2), 5 min). Adhesion molecules ICAM-1 and E-selectin and release of cytokines IL-6 and IL-8 to subsequent stimulation with TNF-alpha (2.5 ng/ml, 4 h) were measured (flow cytometry and immunoassay), as were nuclear translocation of the transcription factor NFkappaB (Western blotting, confocal microscopy) and redox status of HUVECs (quantification of glutathione by HPLC). TNF-alpha elevated IL-6 in the cell supernatant from 8.8 +/- 1 to 41 +/- 3 pg/ml and IL-8 from 0.5 +/- 0. 03 to 3 +/- 0.2 ng/ml. ICAM-1 was increased threefold and E-selectin rose eightfold. Oxidative stress (decrease of glutathione by 50%) reduced post-TNF-alpha levels of IL-6 to 14 +/- 3 and IL-8 to 1 +/- 0.2; the rise of ICAM-1 was completely blocked and E-selectin was only doubled. The anti-inflammatory effects of preconditioning via oxidative stress were paralleled by reduction of the translocation of NFkappaB on stimulation with TNF-alpha, and antagonized by the intracellular radical scavenger N-acetylcysteine. 'Anti-inflammatory preconditioning' of endothelial cells by oxidative stress may account for the inhibitory effects of preconditioning on leukocyte adhesion in vivo.
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PMID:Endothelial preconditioning by transient oxidative stress reduces inflammatory responses of cultured endothelial cells to TNF-alpha. 1069 71

The aim of the present study was to quantitate the temporal changes in protein concentration for interleukin (IL)-1alpha, IL-1beta, IL-1ra, and IL-6 from 1 h to 15 days following focal ischemia. Protein expression was evaluated by enzyme-linked immunosorbent assay utilizing newly available rat antibodies. There were no detectable basal levels of IL-1alpha, 1L-1beta, or IL-6 in the sham-operated or non-ischemic control cortex. IL-1beta (increased significantly (P<0.05) as early as 4 h and peaked at 3 to 5 days. IL-1alpha (increased significantly (P<0.05) at 3 days. IL-6 increased early and peaked at 24 h (P<0.05). IL-1ra increased significantly (P<0.05) over basal levels from 12 h to 5 days. The present study provides the first quantitative determination of interleukin protein concentrations in the rat brain following focal stroke and demonstrates that this technology is now available for mechanistic studies in neuroprotection.
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PMID:Quantitative changes in interleukin proteins following focal stroke in the rat. 1071 23

Reperfusion of the ischemic myocardium is associated with a cytokine cascade that reflects a cellular response to injury. We studied this cascade in the mouse and found that acute surgical trauma in sham-operated animals obscured early changes in cytokine induction that occur during myocardial ischemia-reperfusion (MI/R). Therefore, we utilized a new implantable device that allows occlusion and reperfusion of the left anterior descending coronary artery in a closed-chest mouse at any time after instrumentation. Induction of interleukin (IL)-6 and tumor necrosis factor (TNF)-alpha mRNA in the whole heart was examined by RNase protection assay and quantitated by Phosphor- Imager. At 3 h after instrumentation, levels of IL-6 mRNA in sham-operated animals increased above those of control naive hearts, whereas this increase did not occur until after 1 day for TNF-alpha mRNA. The surgical trauma led to exaggeration of I/R cytokine induction with greater variance in response. At 3 days and 1 wk after instrumentation, levels of both IL-6 and TNF-alpha mRNA in sham-operated animals were comparable to those of naive hearts and induction responses in I/R were much less variant. We also found that 1 h of ischemia and 2 h of reperfusion at all time points of recovery (i.e., 3 h and 1, 3, and 7 days after instrumentation) led to a significant increase in IL-6 and TNF-alpha mRNA levels. In addition, 3 h of permanent occlusion, which did not induce any mRNA increase after 1 wk postinstrumentation, caused marked upregulation of IL-6 mRNA in an acutely prepared animal. This study of early cytokine responses evoked by MI/R highlights the need for dissipation of acute surgical trauma by using a chronic, closed-chest mouse preparation.
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PMID:A chronic mouse model of myocardial ischemia-reperfusion: essential in cytokine studies. 1074 92

Ischemia-reperfusion injury (IRI) is a major cause of renal dysfunction in both native kidneys and renal allografts. To broaden our understanding of the inflammatory mediators involved in IRI, we used multi-probe RNase protection assays to examine the expression of 26 different cytokine genes in a murine model of renal IRI. We observed that, in addition to up-regulation of IL-1beta and to a lesser extent TNF-alpha, IRI was associated with an intense and sustained up-regulation of three gp130-signaling cytokines, IL-6, IL-11, and leukemia inhibitory factor (LIF), as well as with up-regulation of the neutrophil chemotactic and activating mediator macrophage inflammatory protein (MIP)-2. Macrophage colony-stimulating factor (M-CSF) and monocyte chemoattractant protein (MCP)-1 were also moderately up-regulated after IRI, whereas mRNA levels of several other inflammatory mediators including IL-1alpha, IL-2, IL-4, interferon (IFN)-gamma, GM-CSF, and RANTES were minimally increased or remained undetectable. These findings identify MIP-2 as an attractive target for inhibition of leukocyte recruitment in renal IRI and also suggest a potentially novel role for gp130-mediated signals in IRI.
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PMID:Prominent and sustained up-regulation of gp130-signaling cytokines and the chemokine MIP-2 in murine renal ischemia-reperfusion injury. 1075 57

We examined the expression of IL-6 within the ischemic penumbra at various time points after transient (3 h) middle cerebral occlusion (MCA-O) in rats. The animals were killed at 1, 3, 7 or 14 days following operation. Coronal brain sections were processed for immunohistochemistry with antibodies against GFAP, OX 42, IL-6 and Nissl-staining. Glial activation within the penumbra started on day one after ischemia and persisted up to day 14. Expression of IL-6 was not present in sham-operated controls. One day after MCA-O there were several IL-6-positive cells in the penumbra. This expression of IL-6 increased on day 3 and remained elevated up to day 14. According to the shape of the IL-6-positive cells they seem to be microglia and neurons. The present results demonstrate a longlasting expression of IL-6 in the ischemic penumbra.
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PMID:Expression of IL-6 in the ischemic penumbra. 1079 Aug 64

A pathological glia activation, stimulated by inflammatory proteins, beta-amyloid, or brain ischemia, is discussed as a common pathogenic factor for progressive nerve cell damage in vascular and Alzheimer dementia. A critical point seems to be reached, if the cytokine-controlled microglial upregulation causes a secondary activation of astrocytes which loose the negative feedback control, are forced to give up their physiological buffering function, and may add to neuronal damage by the release of nitric oxide (NO) and by promoting toxic beta-amyloid formation. A strengthening of the cyclic adenosine-5',3'-monophosphate (cAMP) signaling exerted a differential inhibition of the stimulatory cytokines tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta (IL-1 beta) released from cultured rat microglia, but maintained the negative feedback signal IL-6; cAMP inhibited also the release of free oxygen radicals (OR) but not of NO. Reinforcement of the NO-induced cyclic guanosine monophosphate (cGMP) increase by blockade of the phosphodiesterase (PDE) subtype-5 with propentofylline counterbalanced the toxic NO action that causes with OR neuronal damage by peroxynitrate formation. In rat cultured astrocytes, a prolonged cAMP elevation favored cell differentiation, the expression of a mature ion channel patter, and an improvement of the extracellular glutamate uptake. Cyclic AMP signaling could be strengthened by PDE blockade and by raising extracellular adenosine, which stimulates A2 receptor-mediated cAMP synthesis. Via an A1 receptor-mediated effect, elevated adenosine was found to overcome a deficient intracellular calcium mobilization resulting from an impaired muscarinic signaling at pathologically decreased acetylcholine concentrations. We suggest that pharmaca, which elevate extracellular adenosine and/or block the degradation of cyclic nucleotides, may be used to counteract glia-related neuronal damage in dementing processes.
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PMID:Cascading glia reactions: a common pathomechanism and its differentiated control by cyclic nucleotide signaling. 1081 85

The novel glycolipid RC-552 shares common structural features with the natural products lipid A and the previously described cardioprotectant monophosphoryl lipid A. RC-552 administered to dogs as a bolus intravenous dose (35-70 microg/kg) either 24 h or 10 min prior to 60 min of regional myocardial ischemia and 3 h of reperfusion significantly (P<0.05 v control) reduced infarct size (IS) as assessed by triphenyltetrazolium staining from 27.0+/-2.3% of the area-at-risk (AAR) to 13.3+/-2.2% and 15.0+/-3.0%, respectively. Administration of the non-specific inducible nitric oxide synthase (iNOS) inhibitor aminoguanidine (30 mg/kg, subcutaneously) 1 h prior to ischemia blocked the ability of RC-552 (35 microg/kg, 24 h pretreatment) to reduce infarct size. Intravenous pretreatment with RC-552 (35 microg/kg) either 24 h or 10 min prior to five 5 min repetitive cycles of ischemia and reperfusion significantly improved regional myocardial segment shortening (percentage of control) at all time points during 2 h of reperfusion in dogs. These effects of RC-552 in either cardiac injury model occurred independent of differences in AAR, transmural blood flow during ischemia or hemodynamics throughout the experiment. In contrast with monophosphoryl lipid A (MLA), which has also been reported to be cardioprotective at similar doses in dogs, RC-552 was approximately 100 times less prone to cause fever in the USP rabbit pyrogen test. Likewise, RC-552 did not induce secretion of the proinflammatory cytokines TNF, IL-6 or IL-8 from THP-1 cells or alter the expression of adhesion molecules on human neutrophils at concentrations up to 10 microg/ml. MLA was active in these systems at concentrations in the range 0.1-1.0 microg/ml. In conclusion, RC-552 reduces myocardial infarct size and stunning in dogs in the absence of residual immunomodulatory activity.
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PMID:The novel glycolipid RC-552 attenuates myocardial stunning and reduces infarct size in dogs. 1086 Jul 73

Acute pancreatitis is a disorder that has numerous causes and an obscure pathogenesis. Bile duct stones and alcohol abuse together account for about 80% of acute pancreatitis. Most episodes of biliary pancreatitis are associated with transient impaction of the stone in the ampulla (that causes obstruction of the pancreatic duct, with ductal hypertension) or passage of the stone though and into the duodenum. Other causes of acute pancreatitis are various toxins, drugs, other obstructive causes (such as malignancy or fibrotic sphincter of Oddi), metabolic abnormalities, trauma, ischemia, infection, autoimmune diseases, etc. In 10% of cases of acute pancreatitis, no underlying cause can be identified; this is idiopathic pancreatitis. Occult biliary microlithiasis may be the cause of two thirds of the cases of "idiopathic" acute pancreatitis. Intra-acinar activation of trypsinogen plays a central role in the pathogenesis of acute pancreatitis, resulting in subsequent activation of other proteases causing the subsequent cell damage. Ischemia/reperfusion injury is increasingly recognized as a common and important mechanism in the pathogenesis of acute pancreatitis and especially in the progression from mild edematous to severe necrotizing form. Increased intracellular calcium concentration also mediates acinar cell damage. Oxygen-derived free radicals and many cytokines (e.g., interleukin [IL]-1, IL-6, IL-8, tumor necrosis factor-alpha, platelet activating factor) are considered to be principal mediators in the transformation of acute pancreatitis from a local inflammatory process into a multiorgan illness.
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PMID:Etiology and pathogenesis of acute pancreatitis: current concepts. 1087 61

Heme oxygenase-1, an inducible heat shock protein, is upregulated by oxidative stress, and its expression is modulated by proinflammatory cytokines such as IL-1 and IL-6. In the present study, we investigated the effects of postlesional, orally applied ebselen, a neuroprotective antioxidant, on serum levels of IL-6 and cerebral heme oxygenase-1 expression following focal ischemia induced by photothrombosis. Ebselen (50 mg/kg body weight) was given 30 min postlesion to male Wistar rats. Animals were divided into four groups: sham-operated vehicle control (n = 9), sham-operated ebselen control (n = 8), lesioned vehicle control (n = 14), and lesioned ebselen-treated (n = 17). Ebselen treatment resulted in a significant lowering of IL-6 plasma levels (26 +/- 5 pg/ml) as compared with that seen in lesioned vehicle controls (48 +/- 9 pg/ml) at 24 h postlesion. In sham-operated rats IL-6 was not detectable. Heme oxygenase-1-positive glial cells were quantitated within topographically determined perilesional brain regions. Within the 0.5-mm-wide rim region directly associated with the lesion core, no differences in the amount of heme oxygenase-1-positive glial cells were found. However, in the more remote ipsilateral perilesional cortex, significantly fewer heme oxygenase-1-positive glial cells were present within the supragranular cortical layers of lesioned ebselen-treated rats compared to lesioned vehicle controls (P < 0.001). In sham-operated rats, no glial heme oxygenase-1 induction occurred. The results indicate that postlesional ebselen treatment lowered plasma IL-6 levels subsequent to a photothrombotic lesion concomitant with a lowering of the heme oxygenase-1 response in glial cells.
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PMID:Ebselen lowers plasma interleukin-6 levels and glial heme oxygenase-1 expression after focal photothrombotic brain ischemia. 1093 77

Multiple organ dysfunction and death are common sequelae after mesenteric ischemia-reperfusion injury as seen with mesenteric revascularization and thoracoabdominal aortic aneurysm repair. A second insult such as bacterial pneumonia occurring subsequent to the ischemia-reperfusion injury may contribute to these untoward effects. We hypothesized the sequential visceral/lower torso ischemia-reperfusion and endotoxemia in a murine model would increase the magnitude of the proinflammatory cytokine response and decrease survival. C57BL/6 mice underwent 20 min of supraceliac occlusion (IR), sham laparotomy (LAP), or no initial insult (CTRL) followed by intraperitoneal injection of a lethal dose of endotoxin (LPS [lipopolysaccharide 50 mg/kg] or saline vehicle at 24 h. Serum cytokine levels were measured by enzyme-linked immunosorbent assay (IL-10, IL-6) or WEHI bioassay [tumor necrosis factor (TNF)], and survival was determined at 5 days. The role of IL-10 on the TNF response and survival was examined in a subset of mice given mouse anti IL-10 IgM (25 mg/kg intraperitoneally) 2 h prior to the initial insult. Survival after LPS was significantly different (P < 0.05) among the treatment groups (IR, 64%; LAP, 55%; CTRL, 11%) and appeared to trend directly with the magnitude of the initial operation. The serum IL-10 levels in the IR and LAP groups were significantly increased 4 h after the initial insult and remained elevated at 24 h. Peak serum TNF levels after LPS were significantly lower in the IR and LAP groups. Administration of anti IL-10 IgM resulted in uniform mortality and a significant increase in the peak TNF levels after LPS administration for all initial treatment groups. Endogenous production of IL-10 following laparotomy down-regulates the TNF response and improves survival after endotoxemia.
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PMID:Laparotomy prevents lethal endotoxemia in a murine sequential insult model by an IL-10-dependent mechanism. 1094 60


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