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)

The function of cytokine-induced neutrophil chemoattractant (CINC), which is the rat counterpart to human growth-related gene product belonging to the CXC chemokine subgroup, is based principally on neutrophil-specific chemotactic activity. In addition, we previously reported that plasma CINC was elevated during the period of small intestinal ischemia-reperfusion injury, and that there was a correlation between the degree of mucosal damage and the peak level of CINC after reperfusion, suggesting that CINC may play a major role in neutrophil infiltration into the rat small intestinal ischemia-reperfusion injury site. Thus, we investigated whether administration of anti-CINC monoclonal antibodies (mAbs) reduces small intestinal ischemia-reperfusion injury. Small intestine was subjected to ischemia for 3 h by occlusion of the anterior mesenteric artery with an atraumatic vascular clump. After infusion of anti-CINC mAbs or isotype-matched mAbs, the intestine was subjected to reperfusion. The pretreatment with anti-CINC mAbs attenuated ischemia-reperfusion injury in the small intestine, in association with the reduction of tumor necrosis factor-alpha and myeloperoxidase production, and resulted in the prolongation of survival. It is concluded that CINC plays an important role in the onset of rat small intestinal ischemia-reperfusion injury. In addition, blocking the action of CINC, namely, the neutrophil chemotactic activity, may be useful in preventing ischemia-reperfusion injury in the small intestine.
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PMID:Prevention of small intestinal ischemia-reperfusion injury in rat by anti-cytokine-induced neutrophil chemoattractant monoclonal antibody. 973 24

Hepatic ischemia/reperfusion (I/R) results in a neutrophil-dependent lung and liver injury. The process of neutrophil recruitment and activation in this injury is at least partially dependent on the presence of the ELR+ CXC chemokines. Other investigations have shown that ELR- CXC chemokines can block ELR+ CXC chemokine neutrophil recruitment and activation in vitro. To begin to investigate the role of the balance between these 2 types of molecules in vivo in neutrophil recruitment and activation following hepatic I/R, we used our rat model of lobar hepatic I/R and pretreated animals with pharmacologic doses of gamma-interferon (gamma-IFN). gamma-IFN is known to upregulate some of the ELR- CXC chemokines, including gamma-IFN-inducible protein (IP-10) and monokine-induced by gamma-IFN (MIG), as well as down-regulate ELR+ CXC chemokine production. Following hepatic I/R or sham laparotomy, hepatic and pulmonary levels of the ELR- chemokines, IP-10 and MIG, and the ELR+ chemokines, rat cytokine-induced neutrophil chemoattractant (KC), macrophage inflammatory protein-2 (MIP-2), and epithelial neutrophil activating protein (ENA-78) were determined by ELISA, and lung and liver injury were assessed. In response to gamma-IFN, hepatic and pulmonary levels of the ELR- chemokines were increased and the levels of the ELR+ chemokines were decreased. Immunohistochemical staining confirmed the hepatocyte as the source of these molecules, as well as the changes in chemokine levels in response to gamma-IFN. There was an associated significant decrease in liver and lung injury, although there was no significant decrease in neutrophil influx in either tissue. This suggests that the alteration in the balance of ELR+ to ELR- CXC chemokines results in a decrease in tissue injury through a mechanism other than through an alteration in tissue neutrophil levels.
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PMID:The ratio of ELR+ to ELR- CXC chemokines affects the lung and liver injury following hepatic ischemia/ reperfusion in the rat. 1065 68

Monokine-induced by gamma interferon (MIG) and gamma-interferon-inducible protein (IP-10) are members of the CXC chemokine family that have been shown to be induced by interferon-gamma (IFNy) in some cell types. The purpose of this investigation was to determine whether IFNgamma influences CXC chemokine production, particularly MIG and IP-10, in primary rat hepatocytes in culture. Previous experiments in our laboratory have demonstrated that pharmacologic doses of IFNgamma in an in vivo model of hepatic ischemia/reperfusion-induced liver injury resulted in increased hepatic levels of IP-10 and MIG and decreased hepatic levels of macrophage inflammatory protein-2, Kupffer cells, and epithelial neutrophil-activating protein, with a concomitant decrease in neutrophil-mediated hepatic injury. In the current investigation, MIG and IP-10 mRNA and protein were up-regulated in primary rat hepatocytes in vitro in response to IFNgamma. Although MIG and IP-10 mRNA were both somewhat increased at early time points, larger increases in these chemokines were seen at later time points, specifically at 24, 48, and 72 h of incubation as compared to controls. Levels of Kupffer cells and macrophage inflammatory protein-2 mRNA after IFNgamma were negligible and similar to those seen in controls. These findings were confirmed by enzyme-linked immunosorbent assay analysis. These studies demonstrate that IFNgamma in vitro up-regulates the production of MIG and IP-10, at both the mRNA and protein levels.
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PMID:CXC chemokine expression after stimulation with interferon-gamma in primary rat hepatocytes in culture. 1206 90

The chemoattractant stromal cell-derived factor-1 (SDF-1) and its receptor CXC chemokine receptor 4 (CXCR4) are key modulators of immune function. In the developing brain, SDF-1 is crucial for neuronal guidance; however, cerebral functions of SDF-1/CXCR4 in adulthood are unclear. Here, we examine the cellular expression of SDF-1 isoforms and CXCR4 in the brain of mice receiving systemic lipopolysaccharide (LPS) or permanent focal cerebral ischemia. CXCR4 mRNA was constitutively expressed in cortical and hippocampal neurons and ependymal cells. Hippocampal neurons targeted the CXCR4 receptor to their somatodendritic and axonal compartments. In cortex and hippocampus, CXCR4-expressing neurons exhibited an overlapping distribution with neurons expressing SDF-1 transcripts. Although neurons synthesized SDF-1alpha mRNA, the SDF-1beta isoform was selectively expressed by endothelial cells of cerebral microvessels. LPS stimulation dramatically decreased endothelial SDF-1beta mRNA expression throughout the forebrain but did not affect neuronal SDF-1alpha. After focal cerebral ischemia, SDF-1beta expression was selectively increased in endothelial cells of penumbral blood vessels and decreased in endothelial cells of nonlesioned brain areas. In the penumbra, SDF-1beta upregulation was associated with a concomitant infiltration of CXCR4-expressing peripheral blood cells, including macrophages. Neuronal SDF-1alpha was transiently downregulated and neuronal CXCR4 was transiently upregulated in the nonlesioned cerebral cortex in response to ischemia. Although endothelial SDF-1beta may control cerebral infiltration of CXCR4-carrying leukocytes during cerebral ischemia, the neuronal SDF-1alpha/CXCR4 system may contribute to ischemia-induced neuronal plasticity. Thus, the isoform-specific regulation of SDF-1 expression modulates neurotransmission and cerebral infiltration via distinct CXCR4-dependent pathways.
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PMID:A dual role for the SDF-1/CXCR4 chemokine receptor system in adult brain: isoform-selective regulation of SDF-1 expression modulates CXCR4-dependent neuronal plasticity and cerebral leukocyte recruitment after focal ischemia. 1212 49

Hepatic ischemia/reperfusion injury is caused primarily by the products of neutrophils recruited into the liver after reperfusion. The mediators responsible for the development of this inflammatory response are thought to be tumor necrosis factor-alpha and interleukin (IL)-1. Although there is abundant evidence to support a role for tumor necrosis factor-alpha, much less is known about the function of IL-1 in this injury. In the present studies, we investigated whether IL-1 was a critical mediator for the induction of liver inflammation after ischemia/reperfusion. Wild-type and IL-1 receptor I-knockout (IL-1RI(-/-)) mice were exposed to 90 minutes of partial hepatic ischemia and up to 24 hours of reperfusion. In wild-type mice, IL-1beta expression was maximal after ischemia and 8 hours of reperfusion. At the same time, both wild-type and IL-1RI(-/-) mice had severe liver injury as assessed by serum alanine aminotransferase levels and hepatic histopathology. However, IL-1RI(-/-) mice had significantly less neutrophil accumulation in liver tissues as measured by liver myeloperoxidase content and histology. The reduction in hepatic neutrophil recruitment in IL-1RI(-/-) mice was associated with decreased activation of the transcription factor, nuclear factor-kappaB, and reduced expression of the CXC chemokine, macrophage inflammatory protein-2. These data suggest that IL-1 functions to augment neutrophil accumulation, but does not play an essential role in this response.
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PMID:Specific role of interleukin-1 in hepatic neutrophil recruitment after ischemia/reperfusion. 1241 26

Recent investigations conducted with human neutrophils have indicated an involvement for the receptor for formylated peptides, termed FPR, and its analog FPRL1 (or ALXR because it is the receptor for the endogenous ligand lipoxin A(4)) in the in vitro inhibitory actions of the glucocorticoid-regulated protein annexin 1 and its peptidomimetics. To translate these findings in in vivo settings, we have used an ischemia/reperfusion (I/R) procedure to promote leukocyte-endothelium interactions in the mouse mesenteric microcirculation. In naive mice, the annexin 1 mimetic peptide Ac2-26 (20 to 100 microg administered intravenously prior to reperfusion) abolished I/R-induced cell adhesion and emigration, but not cell rolling. In FPR-deficient mice, peptide Ac2-26 retained significant inhibitory actions (about 50% of the effects in naive mice), and these were blocked by an FPR antagonist, termed butyloxycarbonyl-Phe-Leu-Phe-Leu-Phe, or Boc2. In vitro, neutrophils taken from these animals could be activated at high concentrations of formyl-Met-Leu-Phe (30 microM; fMLP), and this effect was blocked by cell incubation with peptide Ac2-26 (66 microM) or Boc2 (100 microM). FPR-deficient neutrophils expressed ALXR mRNA and protein. Both ALXR agonists, lipoxin A(4) and peptide Ac2-26, provoked detachment of adherent leukocytes in naive as well as in FPR-deficient mice, whereas the CXC chemokine KC or fMLP were inactive. The present findings demonstrate that endogenous regulatory autocoids such as lipoxin A(4) and annexin 1-derived peptides function to disengage adherent cells during cell-cell interactions.
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PMID:Leukocyte antiadhesive actions of annexin 1: ALXR- and FPR-related anti-inflammatory mechanisms. 1256 Feb 18

Activation and accumulation of leukocytes constitute a rate-limiting step in ischemia/reperfusion (I/R)-induced tissue injury. The signalling mechanisms, however, that regulate leukocyte rolling and adhesion in the colonic microcirculation are not known. The objective of the study was to define the role of CXC chemokines (MIP-2 and KC) in I/R-induced leukocyte-endothelial cell interactions in the mouse colon. In C57/B16 mice, colonic ischemia was induced by clamping the superior mesenteric artery for 30 min and leukocyte rolling and stationary adhesion were examined in venules after 120 and 240 min of reperfusion. I/R provoked a clear-cut increase in leukocyte rolling and adhesion in colonic venules. Both MIP-2 and KC were upregulated at the gene and protein level in the reperfused colon. Immunoneutralization of MIP-2 and KC by monoclonal antibodies reduced reperfusion-induced firm adhesion of leukocytes by 73% and 75%, respectively. Interestingly, combined inhibition of MIP-2 and KC additionally decreased leukocyte rolling by 79%, but did not further reduce the number of firmly adherent leukocytes. To study the role of oxygen free radicals (OFRs) in the regulation of CXC chemokine expression, additional animals were pretreated with the xanthine-oxidase inhibitor allopurinol. In fact, allopurinol treatment reduced the colonic levels of MIP-2 and KC by 62% and 64%, respectively. This study elucidates important interactions between OFRs and chemokines in the I/R-induced leukocyte response in the mouse colon. Moreover, our data demonstrate that CXC chemokines play a fundamental role in colonic I/R and that functional interference with CXC chemokines may protect against pathological inflammation in the colon.
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PMID:Oxygen radical-dependent expression of CXC chemokines regulate ischemia/reperfusion-induced leukocyte adhesion in the mouse colon. 1458 42

Hepatic ischemia/reperfusion injury is a clinically important problem. While the mechanisms of the initial event and subsequent neutrophil-dependent injury are somewhat understood, little is known about the regulation of endogenous hepatoprotective effects on this injury. Interleukin 12 (IL-12) plays a role in the induction of this injury, but involvement of interleukin 18 (IL-18) has not been clarified. Using a murine model of partial hepatic ischemia and subsequent reperfusion, the aim of the current study was to determine whether IL-18 is up-regulated during hepatic ischemia/reperfusion and to determine the role of endogenous IL-18 in the development and regulation of inflammatory hepatic ischemia/reperfusion injury. Hepatic IL-18 expression was up-regulated from 1 to 8 hours after reperfusion. Hepatic ischemia/reperfusion induced nuclear factor-kappaB (NF-kappaB) and activator protein 1 (AP-1) activation, as defined by electrophoretic mobility shift assay, and caused significant increases in liver neutrophil recruitment, apoptosis, hepatocellular injury, and liver edema as defined by liver myeloperoxidase content, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate biotin nick end-labeling (TUNEL) staining, serum aminotransferase levels, and liver wet-to-dry weight ratios. In mice treated with neutralizing antibody to IL-18, ischemia/reperfusion-induced increases in CXC chemokine expression, activation of NF-kappaB and AP-1, and apoptosis were greatly reduced. Furthermore, under blockade of IL-18, anti-inflammatory cytokines such as IL-4 and IL-10 were greatly up-regulated. Signal transducer and activator of transcription 6 (STAT6) was significantly activated under blockade of IL-18. These conditions also caused significant reduction in liver neutrophil sequestration and liver injury. In conclusion, the data suggest that IL-18 is required for facilitating neutrophil-dependent hepatic ischemia/reperfusion injury through suppressing anti-inflammatory cytokine expression.
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PMID:Interleukin 18 causes hepatic ischemia/reperfusion injury by suppressing anti-inflammatory cytokine expression in mice. 1499 88

Recent interest in the annexin 1 field has come from the notion that specific G-protein-coupled receptors, members of the formyl-peptide receptor (FPR) family, appear to mediate the anti-inflammatory actions of this endogenous mediator. Administration of the annexin 1 N-terminal derived peptide Ac2-26 to mice after 25 min ischemia significantly attenuated the extent of acute myocardial injury as assessed 60 min postreperfusion. Evident at the dose of 1 mg/kg (approximately 9 nmol per animal), peptide Ac2-26 cardioprotection was intact in FPR null mice. Similarly, peptide Ac2-26 inhibition of specific markers of heart injury (specifically myeloperoxidase activity, CXC chemokine KC contents, and endogenous annexin 1 protein expression) was virtually identical in heart samples collected from wild-type and FPR null mice. Mouse myocardium expressed the mRNA for FPR and the structurally related lipoxin A4 receptor, termed ALX; thus, comparable equimolar doses of two ALX agonists (W peptide and a stable lipoxin A4 analog) exerted cardioprotection in wild-type and FPR null mice to an equal extent. Curiously, marked (>95%) blood neutropenia produced by an anti-mouse neutrophil serum did not modify the extent of acute heart injury, whereas it prevented the protection afforded by peptide Ac2-26. Thus, this study sheds light on the receptor mechanism(s) mediating annexin 1-induced cardioprotection and shows a pivotal role for ALX and circulating neutrophil, whereas it excludes any functional involvement of mouse FPR. These mechanistic data can help in developing novel therapeutics for acute cardioprotection.
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PMID:Formyl-peptide receptor is not involved in the protection afforded by annexin 1 in murine acute myocardial infarct. 1550 72

Myocardial infarction is associated with an inflammatory response leading to leukocyte recruitment, healing and formation of a scar. Members of the chemokine superfamily are rapidly induced in the infarcted myocardium and may critically regulate the post-infarction inflammatory response. CXCL8/Interleukin (IL)-8 is upregulated in the infarcted area and may induce neutrophil infiltration. In addition, mononuclear cell chemoattractants, such as the CC chemokines CCL2/Monocyte Chemoattractant Protein (MCP)-1, CCL3/Macrophage Inflammatory Protein (MIP)1alpha, and CCL4/MIP-1beta are expressed in the ischemic area, and may regulate monocyte and lymphocyte recruitment. However, chemokines may have additional effects on healing infarcts beyond their leukotactic properties. The CXC chemokine CXCL10/Interferon-y inducible Protein (IP)-10, a potent angiostatic factor with antifibrotic properties, is induced in the infarct and may prevent premature angiogenesis and fibrous tissue deposition, until the infarct is debrided and provisional matrix necessary to support granulation tissue ingrowth is formed. Chemokine induction in the infarct is transient, suggesting that inhibitory mediators (such as transforming growth Factor (TGF)-beta) may be activated suppressing chemokine synthesis and leading to resolution of inflammation and transition to fibrosis. Brief repetitive ischemia in mice also results in chemokine upregulation followed by suppression of chemokine synthesis and interstitial fibrosis, in the absence of myocardial infarction. Chemokine expression may play a role in the pathogenesis of non-infarctive ischemic cardiomyopathy, where early ischemia-induced chemokine expression may be followed by activation of inhibitory mediators that suppress inflammation, but induce fibrosis.
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PMID:Chemokines in the ischemic myocardium: from inflammation to fibrosis. 1569 6


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