Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UNIPROT:P00750 (PLA)
16,800 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The combination of hyperbaric oxygen therapy (HBO) and recombinant tissue-plasminogen activator (tPA) is of interest in the treatment of acute ischemic stroke with a view to combine positive effects of both strategies. We investigated neurological and functional outcome after early treatment with HBO additional to tPA in ischemic stroke. Focal cerebral ischemia was induced using an embolic stroke model in 87 male Wistar rats. Animals were randomized to therapy with tPA+HBO, tPA alone, or control. Menzies score, Beam walk, and the Corner test were assessed for a period of 4 weeks following ischemia. Within the first 24 h neurological deficits improved in all groups but most pronounced in animals treated with tPA+HBO. Thereafter, a deterioration of neurological deficits occurred in the tPA+HBO group with significant differences at day 7, 8, 18, and 24 (P<0.05). Surprisingly, Beam walk and Corner test results did not differ significantly between all groups. This first report of early simultaneous treatment with tPA and HBO in experimental embolic stroke with 4-week follow-up confirms previous studies reporting positive effects of HBO shortly after the ischemia. Following the acute phase, combined tPA and HBO resulted in deterioration of neurological deficits without affecting functional recovery. Future studies should focus on interactions of tPA and HBO on molecular level leading to delayed damage to brain tissue at risk.
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PMID:Long-term functional and neurological outcome after simultaneous treatment with tissue-plasminogen activator and hyperbaric oxygen in early phase of embolic stroke in rats. 1976 3

Granulocyte-Macrophage Colony Stimulating Factor (GM-CSF) is a proinflammatory cytokine with neuroprotective and angiogenic properties demonstrated in animal models of cerebral ischemia but their role in human ischemic stroke is still unknown. Thus, our aim is to determine human GM-CSF plasma level in control subjects and stroke patients and its relationship to clinical outcome. Forty-three patients with middle cerebral artery occlusion who received thrombolytic therapy within the first three hours of stroke onset and nineteen healthy controls were included. Blood samples were drawn before tissue plasminogen activator (t-PA) treatment. In a group of thirteen strokes blood samples were also obtained one hour after t-PA treatment, at 24 hours of symptoms onset, at discharge and at three months. GM-CSF levels were determined by enzyme-linked immunosorbent assay (ELISA). Stroke severity and neurological outcome was assessed by National Institutes of Health Stroke Scale (NIHSS) and functional outcome were scored by modified Rankin Scale (mRS) at 3 months. Baseline GM-CSF level was significantly higher in stroke patients than in healthy controls (17.8 pg/ml vs 12.8 pg/ml); p<0.0001 and was positively correlated with NIHSS score at 12 hours (R=0.3, p=0.03). No association was detected with functional status at three months measured by mRS. Temporary profile of GM-CSF level in stroke patients gradually decreases from admission to three months. Higher plasma endogenous GM-CSF level is found in stroke patients compared to controls. However, no relation was found with a better outcome. Further research is necessary for elucidating the role of GM-CSF in ischemic stroke.
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PMID:Role of endogenous granulocyte-macrophage colony stimulating factor following stroke and relationship to neurological outcome. 1980 55

Acute ischemic stroke is the third leading cause of death in industrialized countries and the most frequent cause of permanent disability in adults worldwide. Despite advances in the understanding of the pathophysiology of cerebral ischemia, therapeutic options remain limited. Only recombinant tissue-plasminogen activator (rt-PA) for thrombolysis is currently approved for use in the treatment of this devastating disease. However, its use is limited by its short therapeutic window (three hours), complications derived essentially from the risk of hemorrhage, and the potential damage from reperfusion/ischemic injury. Two important pathophysiological mechanisms involved during ischemic stroke are oxidative stress and inflammation. Brain tissue is not well equipped with antioxidant defenses, so reactive oxygen species and other free radicals/oxidants, released by inflammatory cells, threaten tissue viability in the vicinity of the ischemic core. This review will discuss the molecular aspects of oxidative stress and inflammation in ischemic stroke and potential therapeutic strategies that target neuroinflammation and the innate immune system. Currently, little is known about endogenous counterregulatory immune mechanisms. However, recent studies showing that regulatory T cells are major cerebroprotective immunomodulators after stroke suggest that targeting the endogenous adaptive immune response may offer novel promising neuroprotectant therapies.
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PMID:Inflammatory mechanisms in ischemic stroke: therapeutic approaches. 1991 99

To develop an effective neuroprotective strategy against ischemic injury, it is important to identify the key molecules involved in the progression of injury. Direct molecular analysis of tissue using mass spectrometry (MS) is a subject of much interest in the field of metabolomics. Most notably, imaging mass spectrometry (IMS) allows visualization of molecular distributions on the tissue surface. To understand lipid dynamics during ischemic injury, we performed IMS analysis on rat brain tissue sections with focal cerebral ischemia. Sprague-Dawley rats were sacrificed at 24 h after middle cerebral artery occlusion, and brain sections were prepared. IMS analyses were conducted using matrix-assisted laser desorption/ionization time-of-flight mass spectrometer (MALDI-TOF MS) in positive ion mode. To determine the molecular structures, the detected ions were subjected to tandem MS. The intensity counts of the ion signals of m/z 798.5 and m/z 760.5 that are revealed to be a phosphatidylcholine, PC (16:0/18:1) are reduced in the area of focal cerebral ischemia as compared to the normal cerebral area. In contrast, the signal of m/z 496.3, identified as a lyso-phosphatidylcholine, LPC (16:0), was clearly increased in the area of focal cerebral ischemia. In IMS analyses, changes of PC (16:0/18:1) and LPC (16:0) are observed beyond the border of the injured area. Together with previous reports--that PCs are hydrolyzed by phospholipase A(2) (PLA(2)) and produce LPCs,--our present results suggest that LPC (16:0) is generated during the injury process after cerebral ischemia, presumably via PLA(2) activation, and that PC (16:0/18:1) is one of its precursor molecules.
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PMID:Imaging mass spectrometry revealed the production of lyso-phosphatidylcholine in the injured ischemic rat brain. 2036 43

The sole FDA-approved treatment for acute stroke is recombinant tissue-type plasminogen activator (rtPA). However, rtPA aggravates the impairment of cerebrovasodilation induced by global hypoxia/ischemia; this impairment is attenuated by the preinjury treatment with the plasminogen activator inhibitor derivative EEIIMD. MAPK (a family of kinases, p38, and JNK) is upregulated after cerebral ischemia. In this study, we determined whether the novel plasminogen activator inhibitor-derived peptide, Ac-RMAPEEIIMDRPFLYVVR-amide, (PAI-1-DP) given 30 min before or 2 h after, focal central nervous system injury induced by photothrombosis would preserve responses to cerebrovasodilators and the role of p38 and JNK MAPK in such effects. Cerebrospinal fluid JNK and p38 levels were elevated by photothrombotic injury, an effect potentiated by rtPA. Cerebrovasodilation was blunted by photothrombosis and reversed to vasoconstriction by rtPA but restored to dilation by PAI-1-DP pre- and posttreatment. PAI-1-DP blocked JNK, but preserved p38 MAPK upregulation after photothrombosis. The JNK MAPK antagonist SP600125 prevented, and the p38 antagonist SB203580 potentiated, impaired cerebrovasodilation after photothrombosis. These data indicate that rtPA impairs cerebrovasodilation after injury by activating JNK, while p38 MAPK is protective, and that the novel peptide PAI-1-DP protects by inhibiting activation of JNK by rtPA. JNK MAPK inhibitors, including PAI-1-DP, may offer a novel approach to increase the benefit-to-risk ratio of thrombolytic therapy and enable its use in central nervous system ischemic disorders.
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PMID:Novel plasminogen activator inhibitor-1-derived peptide protects against impairment of cerebrovasodilation after photothrombosis through inhibition of JNK MAPK. 2053 98

One of the therapeutics for acute cerebral ischemia is tissue plasminogen activator (t-PA). Using t-PA after 3 hour time window increases the chances of hemorrhage, involving multiple mechanisms. In order to show possible mechanisms of t-PA toxicity and the effect of the free radical scavenger edaravone, we administered vehicle, plasmin, and t-PA into intact rat cortex, and edaravone intravenously. Plasmin and t-PA damaged rat brain with the most prominent injury in t-PA group on 4-HNE, HEL, and 8-OHdG immunostainings. Such brain damage was strongly decreased in t-PA plus edaravone group. For the neurovascular unit immunostainings, occludin and collagen IV expression was decreased in single plasmin or t-PA group, which was recovered in t-PA plus edaravone group. In contrast, matrix metalloproteinase-9 intensity was the strongest in t-PA group, less in plasmin, and was the least prominent in t-PA plus edaravone group. In vitro data showed a strong damage to tight junctions for occludin and claudin 5 in both administration groups, while there were no changes for endothelial (NAGO) and perivascular (GFAP) stainings. Such damage to tight junctions was recovered in t-PA plus edaravone group with similar recovery in Sodium-Fluorescein permeability assay. Administration of t-PA caused oxidative stress damage to lipids, proteins and DNA, and led to disruption of outer parts of neurovascular unit, greater than the effect in plasmin administration. Additive edaravone ameliorated such an oxidative damage by t-PA with protecting outer layers of blood-brain barrier (in vivo) and tight junctions (in vitro).
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PMID:Free radical scavenger edaravone administration protects against tissue plasminogen activator induced oxidative stress and blood brain barrier damage. 2085 48

Matrix metalloproteinase-9 (MMP-9) is a possible marker for acute ischemic stroke (AIS). In animal models of cerebral ischemia, MMP expression was significantly increased and was related to blood-brain barrier disruption, vasogenic edema formation, and hemorrhagic transformation. The definition of the exact role of MMPs after ischemic stroke will have important diagnostic implications for stroke and for the development of therapeutic strategies aimed at modulating MMPs. The objectives of the present study were to determine (1) whether MMP-9 is a possible marker for AIS; (2) whether MMP-9 levels correlate with infarct volume, stroke severity, or functional outcome; and (3) whether MMP-9 levels correlate with the development of hemorrhagic transformation after tissue plasminogen activator (t-PA) administration. The literature was searched using MEDLINE and EMBASE with no year restriction. All relevant reports were included. A total of 22 studies (3,289 patients) satisfied the inclusion criteria. Our review revealed that higher MMP-9 values were significantly correlated with larger infarct volume, severity of stroke, and worse functional outcome. There were significant differences in MMP-9 levels between patients with AIS and healthy control subjects. Moreover, MMP-9 was a predictor of the development of intracerebral hemorrhage in patients treated with thrombolytic therapy. MMP-9 level was significantly increased after stroke onset, with the level correlating with infarct volume, stroke severity, and functional outcome. MMP-9 is a possible marker for ongoing brain ischemia, as well as a predictor of hemorrhage in patients treated with t-PA.
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PMID:Matrix metalloproteinase-9 as a marker for acute ischemic stroke: a systematic review. 2104 10

Stroke is one of the most important causes of mortality and morbidity in the world. Prevention and effective treatment of stroke is of the utmost importance. Cerebral ischemia causes disturbances in a variety of cellular and molecular mechanisms, including oxidative phosphorylation, membrane function, neurotransmitter release, and free radical generation. It has been years since tissue-type plasminogen activator (t-PA) became the first medication approved by the FDA for the management of stroke, with limited success. Thrombolytic therapy is the most effective therapeutic strategy for the prevention of brain injury and reduction of mortality in patients with cerebral infarction. However, a combination of established thrombolytic therapy and effective neuronal protection therapy may have more beneficial effects for patients with cerebral infarction. Because clinical trials of pharmacological neuroprotective strategies in stroke have been disappointing, attention has turned towards approaches which include herbal drugs that can be used in limiting the neurological damage associated with stroke. Herbal drugs may be used as prophylactic treatment in patients with high risk of stroke. Herbals drugs have been described in ancient systems of medicine for the treatment of various ailments associated with stroke and have more recently been reported to be beneficial in treating stroke. However, the strength of evidence to support the use of these herbal drugs is unclear. This review focuses on putative mechanisms underlying the beneficial effects of herbal drugs in patients with stroke and on the possibility of herbal drugs to increase the therapeutic time window in patients with cerebral ischemia.
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PMID:Therapeutic potential of herbal drugs in cerebral ischemia. 2109 May 28

This study sought to identify potential targets for acute stroke therapy that can be exploited pharmacologically beyond the current 4.5h time limit for clinical administration of recombinant tissue-plasminogen activator. We used PCR arrays to initially screen the temporal expression profiles of several chemokine-related genes in the brain at 4, 24 and 72h after stroke. We identified large increases (>10-fold) in mRNA at 24 or 72h for the neutrophil CXCR2 receptor, and for CXCL1 and CXCL2-two chemokine ligands expressed by monocytes and neutrophils with strong neutrophil chemoattractant activity via CXCR2. We then tested the efficacy of a CXCR2 antagonist as a therapeutic. Mice were treated with vehicle (1% DMSO) or SB225002 (2mg/kg per day, ip) commencing at reperfusion, and we evaluated chemokine gene expression, neutrophil infiltration and functional and histological endpoints of stroke outcome. Expression levels of CXCL1, CXCL2 and CXCR2 after 24h were markedly reduced to near normal levels in SB225002-treated mice. Myeloperoxidase-positive cell infiltration was significantly reduced in SB225002-treated mice compared with vehicle-treated mice, and was similar to levels in sham-operated mice. However, although SB225002 evidently antagonised the interaction between CXCR2 and its chemokine ligands in the ischemic brain, mice treated with either SB225002 or vehicle had similar motor impairment and infarct volume at 72h. Thus, the reduced expression of CXC chemokine subfamily genes and neutrophil-related infiltration following SB225002 administration did not improve outcome after cerebral ischemia-reperfusion. CXCR2 antagonists are therefore unlikely to be a potential therapy for ischemic stroke.
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PMID:Chemokine-related gene expression in the brain following ischemic stroke: no role for CXCR2 in outcome. 2113 35

Treatment of acute ischemic stroke with intravenous tissue-type plasminogen activator is underutilized partly due to the risk of life-threatening hemorrhage. In response to the clinical need for safer stroke therapy, we explored using an aptamer-based therapeutic strategy to promote cerebral reperfusion in a murine model of ischemic stroke. Aptamers are nucleic acid ligands that bind to their targets with high affinity and specificity, and can be rapidly reversed with an antidote. Here we show that a Factor IXa aptamer administered intravenously after 60 minutes of cerebral ischemia and reperfusion improved neurological function and was associated with reduced thrombin generation and decreased inflammation. Moreover, when the aptamer was administered in the setting of intracranial hemorrhage, treatment with its specific antidote reduced hematoma volume and improved survival. The ability to rapidly reverse a pharmacologic agent that improves neurological function after ischemic stroke should intracranial hemorrhage arise indicates that aptamer-antidote pairs may represent a novel, safer approach to treatment of stroke.
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PMID:A reversible aptamer improves outcome and safety in murine models of stroke and hemorrhage. 2114 78


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