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)

Recent studies demonstrated that resveratrol, a grape-derived polyphenolic phytoalexin, provides pharmacological preconditioning of the heart through a NO-dependent mechanism. To further explore the molecular mechanisms involved in resveratrol-mediated cardioprotection, we monitored the effects of resveratrol treatment after ischemia-reperfusion on the protein profile by implementation of proteomic analysis. Two groups of rats were studied; one group of animals was fed resveratrol for 7 days, while the other group was given vehicle only. The rats were sacrificed for the isolated working heart preparation and for isolation of cytoplasmic fraction from left ventricle homogenates to carry out the proteomic as well as immunoblot at baseline and at the end of 30 min ischemia/2-h perfusion. The results demonstrate significant cardioprotection with resveratrol evidenced by improved ventricular recovery and reduced infarct size and cardiomyocyte apoptosis. The left ventricular cytoplasmic fractions were separated by two-dimensional electrophoresis (2-DE). Differentially regulated proteins were detected with quantitative computer analysis of the Coomassie blue stained 2-DE images and identified by MALDI-TOF (MS) and nanoLC-ESI-Q-TOF mass spectrometry (MS/MS). Five redox-regulated and preconditioning- related proteins were identified that were all upregulated by resveratrol: MAPKK, two different alphaB-crystallin species, HSP 27 and PE binding protein. Another HSP27 species and aldose reductase were downregulated and peroxiredoxin- 2 remained constant. The results of the immunoblot analysis of phosphorylated MAPKK, -HSP27 and -alphaB-crystallin and PE binding protein were consistent with the proteomic findings, but not with peroxiredoxin-2. The proteomic analysis showed also downregulation of some proteins in the mitochondrial respiratory chain and matrix and the myofilament regulating protein MLC kinase-2. The results of the present study demonstrate that proteomic profiling enables the identification of resveratrol induced preconditioning-associated proteins which reflects not only changes in their expression level but also isoforms, post-translational modifications and regulating binding or activating partner proteins.
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PMID:Differential proteomic profiling to study the mechanism of cardiac pharmacological preconditioning by resveratrol. 2318 35

Oxidative stress is one of the major causes of neuronal cell death in disorders such as perinatal hypoxia and ischemia. Protein phosphorylation is the most significant PTM of proteins and plays an important role in stress-induced signal transduction. Thus, the analysis of alternative protein phosphorylation states which occur during oxidative stress-induced cell death could provide valuable information regarding cell death. In this study, a reference phosphoproteome map of the mouse hippocampal cell line HT22 was constructed based on 125 spots that were identified by MALDI-TOF or LC-ESI-Q-TOF-MS analysis. In addition, proteins of HT22 cells at various stages of oxidative stress-induced cell death were separated by 2-DE and alterations in phosphoproteins were detected by Pro-Q Diamond staining. A total of 17 spots showing significant quantitative changes and seven newly appearing spots were identified after glutamate treatment. Splicing factor 2, peroxiredoxin 2, S100 calcium binding protein A11, and purine nucleoside phosphorylase were identified as up- or down-regulated proteins. CDC25A, caspase-8, and cyp51 protein appeared during oxidative stress-induced cell death. The data in this study from phosphoproteomic analysis provide a valuable resource for the understanding of HT22 cell death mechanisms mediated by oxidative stress.
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PMID:Phosphoproteomic analysis of neuronal cell death by glutamate-induced oxidative stress. 1761 Feb 4

Serine/threonine protein phosphatase 1 (PP1) regulates multiple cellular processes. Protein phosphorylation-dephosphorylation is largely altered during ischemia and subsequent reperfusion. The brain is particularly vulnerable to stress resulting from ischemia-reperfusion (IR), however, the acquisition of ischemic tolerance (IT) protects against IR stress. We studied PP1 complexes in response to IR stress and IT in brain using proteomic characterization of PP1 complexes in animal models of IR and IT. PP1alpha and PP1gamma were immunoprecipitated and resolved by 2-D. DIGE analysis detected 14 different PP1-interacting proteins that exhibited significant changes in their association with PP1alpha or PP1gamma. These proteins were identified by MALDI-TOF MS. Seven had the PP1-binding RVxF motif. IR altered the interaction of heat shock cognate 71 kDa-protein, creatine kinase B, and dopamine- and cAMP-regulated phosphoprotein 32 kDa (DARPP32) with both PP1alpha and PP1gamma, and the interaction of phosphodiesterase-6B, transitional ER ATPase, lamin-A, glucose-regulated 78 kDa-protein, dihydropyrimidinase-related protein-2, gamma-enolase, neurofilament-L, and ubiquitin ligase SIAH2 with PP1gamma. IT prevented most of the IR-induced effects. This study identifies novel PP1alpha- and PP1gamma-interacting proteins and reveals an in vivo modularity of PP1 holoenzymes in response to physiological ischemic stress. It supports a potential role of PP1 in IR stress and as a target of the endogenous protective mechanisms induced by IT.
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PMID:Proteomic characterization of protein phosphatase 1 complexes in ischemia-reperfusion and ischemic tolerance. 1768 50

Oxidative stress is a condition occurring in liver disorders and causing liver damage due to ischemia-reperfusion (I/R) during liver transplantation. Several markers of chronic oxidative stress are well known; however, early protein targets of oxidative injury are not well defined. To identify them, we used a differential proteomics approach to HepG2 human liver cells that has been treated for 10 minutes with 500 micromol/L H(2)O(2). By differential proteomic analysis, using two-dimensional gel electrophoresis and MALDI-TOF mass spectrometry, we identified four proteins sensitive to H(2)O(2) treatment that underwent posttranslational modification of native polypeptides. Three of the proteins belong to the Peroxiredoxin family of hydroperoxide scavengers, PrxI, PrxII, and Prx VI, that showed changes in their pI as result of hyperoxidation. Mass mapping experiments demonstrated specific modification of the peroxiredoxins active site thiol into sulphinic and/or sulphonic acid, thus explaining an increased negative charge. The oxidation kinetics of all peroxiredoxins were extremely rapid and sensitive, occurring at H(2)O(2) doses unable to affect common markers of cellular oxidative stress. A differential proteomics approach was also applied to liver needle biopsies after cold (T(1)) and warm (T(2)) ischemia. Proteomic analysis of this material was related to histological changes and immunophenotypic expression of APE1/Ref-1. Hyperoxidation of PrxI occurring during I/R upon liver transplantation is dependent on the time of warm ischemia. Histological changes and APE1/Ref-1 expression parallel Peroxiredoxin changes. Our present data may be relevant to better graft preservation and evaluation for transplantation.
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PMID:Redox proteomics and immunohistology to study molecular events during ischemia-reperfusion in human liver. 1769 4

Hibernating myocardium is accompanied by a downregulation in energy utilization that prevents the immediate development of ischemia during stress at the expense of an attenuated level of regional contractile function. We used a discovery based proteomic approach to identify novel regional molecular adaptations responsible for this phenomenon in subendocardial samples from swine instrumented with a chronic LAD stenosis. After 3 months (n=8), hibernating myocardium was present as reflected by reduced resting LAD flow (0.75+/-0.14 versus 1.19+/-0.14 mL x min(-1) x g(-1) in remote) and wall thickening (1.93+/-0.46 mm versus 5.46+/-0.41 mm in remote, P<0.05). Regionally altered proteins were quantified with 2D Differential-in-Gel Electrophoresis (2D-DIGE) using normal myocardium as a reference with identification of candidates using MALDI-TOF mass spectrometry. Hibernating myocardium developed a significant downregulation of many mitochondrial proteins and an upregulation of stress proteins. Of particular note, the major entry points to oxidative metabolism (eg, pyruvate dehydrogenase complex and Acyl-CoA dehydrogenase) and enzymes involved in electron transport (eg, complexes I, III, and V) were reduced (P<0.05). Multiple subunits within an enzyme complex frequently showed a concordant downregulation in abundance leading to an amplification of their cumulative effects on activity (eg, "total" LAD PDC activity was 21.9+/-3.1 versus 42.8+/-1.9 mU, P<0.05). After 5-months (n=10), changes in mitochondrial and stress proteins persisted whereas cytoskeletal proteins (eg, desmin and vimentin) normalized. These data indicate that the proteomic phenotype of hibernating myocardium is dynamic and has similarities to global changes in energy substrate metabolism and function in the advanced failing heart. These proteomic changes may limit oxidative injury and apoptosis and impact functional recovery after revascularization.
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PMID:Persistent regional downregulation in mitochondrial enzymes and upregulation of stress proteins in swine with chronic hibernating myocardium. 1817 69

The distribution and movement of elemental ions in biologic tissues is critical for many cellular processes. In contrast to chemical techniques for imaging the intracellular distribution of ions, however, techniques for imaging the distribution of ions across tissues are not well developed. We used time-of-flight secondary ion mass spectrometry (TOF-SIMS) to obtain nonlabeled high-resolution analytic images of ion distribution in ischemic retinal tissues. Marked changes in Ca(2+) distribution, compared with other fundamental ions, such as Na(+), K(+), and Mg(2+), were detected during the progression of ischemia. Furthermore, the Ca(2+) redistribution pattern correlated closely with TUNEL-positive (positive for terminal deoxynucleotidyl transferase-mediated 2'-deoxyuridine 5'-triphosphate nick end-labeling) cell death in ischemic retinas. After treatment with a calcium chelator, Ca(2+) ion redistribution was delayed, resulting in a decrease in TUNEL-positive cells. These results indicate that ischemia-induced Ca(2+) redistribution within retinal tissues is associated with the order of apoptotic cell death, which possibly explains the different susceptibility of various types of retinal cells to ischemia. Thus, the TOF-SIMS technique provides a tool for the study of intercellular communication by Ca(2+) ion movement.
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PMID:Label-free calcium imaging in ischemic retinal tissue by TOF-SIMS. 1822 31

Hypoxia-induced responses are frequently encountered during cardiovascular injuries. Hypoxia triggers intracellular reactive oxygen species/nitric oxide (NO) imbalance. Recent studies indicate that NO-mediated S-nitrosylation (S-NO) of cysteine residue is a key posttranslational modification of proteins. We demonstrated that acute hypoxia to endothelial cells (ECs) transiently increased the NO levels via endothelial NO synthase (eNOS) activation. A modified biotin-switch method coupled with Western blot on 2-dimensional electrophoresis (2-DE) demonstrated that at least 11 major proteins have significant increase in S-NO after acute hypoxia. Mass analysis by CapLC/Q-TOF identified those as Ras-GTPase-activating protein, protein disulfide-isomerase, human elongation factor-1-delta, tyrosine 3/tryptophan 5-monooxygenase activating protein, and several cytoskeleton proteins. The S-nitrosylated cysteine residue on tropomyosin (Cys 170) and beta-actin (Cys 285) was further verified with the trypsic peptides analyzed by MASCOT search program. Further understanding of the functional relevance of these S-nitrosylated proteins may provide a molecular basis for treating ischemia-induced vascular disorders.
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PMID:Acute hypoxia enhances proteins' S-nitrosylation in endothelial cells. 1899 11

Hepatic ischemia/reperfusion (I/R) injury is an inevitable consequence during liver surgery. Ischemic preconditioning (IPC) has been shown to protect the livers from I/R injury, partially mediated by preservation of hepatic ATP contents. However, the precise molecular mechanisms of these events remain poorly elucidated. In this study, liver proteomes of the mice subjected to I/R injury pretreated with or without IPC were analyzed using 2-DE combined with MALDI-TOF/TOF mass analysis. Twenty proteins showing more than 1.5-fold difference were identified in the livers upon I/R injury. Among these proteins, four proteins were further regulated by IPC when compared with nonpretreated controls. One of these proteins, ATP synthase beta subunit (ATP5beta) catalyzes the rate-limiting step of ATP formation. The expression level of ATP5beta, which was further validated by Western blot analysis, was significantly decreased upon I/R injury while turned over by IPC pretreatment. Change pattern of hepatic ATP corresponded with that of ATP5beta expression, indicating that increasing hepatic ATP5beta expression might be a reason for ATP-preserving effect of IPC. In summary, this study provided new clues for understanding the mechanisms of IPC against I/R injury. The protective role of ATP5beta might give evidences for developing new therapeutic approaches against hepatic I/R injury.
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PMID:Proteomic analysis of hepatic ischemia/reperfusion injury and ischemic preconditioning in mice revealed the protective role of ATP5beta. 1914 48

Although DNA microarray studies showed up-regulation of various genes, failures of translation of many genes are expected to occur under ischemic conditions even in the penumbra with mild reduction in cerebral blood flow. We applied surface enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF-MS) technology to study proteomic profile at 6, 12, and 24 h after photothrombotic middle cerebral artery (MCA) occlusion with or without YAG laser-induced reperfusion in adult male spontaneously hypertensive rats. Of the 43 protein peaks that differed from the sham-operation group with a criterion (no overlap of peak intensities between the two groups), 36 peaks (84%) were down-regulated, and seven were up-regulated. All increased peaks showed greater than twofold increases (up to 8.1 fold) compared with those in the sham-operation group. Effects of reperfusion were observed mainly at 24 h after 1 h of MCA occlusion only in the penumbra, where 23 of 32 peaks returned toward the control values, whereas none of 33 peaks showed such attenuation in the ischemic core. Major ischemia-induced changes in protein peaks detected with SELDI-TOF-MS were down-regulations. The present study showed that dynamic changes of protein profile were associated with progression and recovery of the ischemic core and penumbra.
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PMID:Regional and temporal changes in proteomic profile after middle cerebral artery occlusion with or without reperfusion in rats. 1944 5

Stroke, a deleterious cerebrovascular event, is caused by a critical reduction in the blood flow to the brain parenchyma that leads to brain injury and loss of brain functions. The inflammatory responses following ischemia often aggravate the neurological damage. Several pro-inflammatory mediators released after stroke are closely related to the metabolism of phospholipids. In this study we directly profiled the changes in phospholipids in the infarcted rat cerebral cortex 24 hours after middle cerebral artery occlusion (MCAO) using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). Several phosphatidylcholine (PC) species and sphingomyelin (SM) were significantly decreased after infarction. The cationization pattern of the remaining PCs showed a prominent shift from a mostly potassiated or protonated form to a predominantly sodiated pattern. Stroke also elevated the lysophosphatidylcholines (LPCs) and heme in tissue. The isobaric pairs in PC and LPC classes were resolved by masses through their respective alkali metal adducts in the presence of CsCl. The major fatty acyl LPC species were also structurally confirmed by MALDI-MS/MS. Overall, the results described the changes in PC and LPC species in the infarcted rat cortex. The elevated tissue levels of LPCs and heme signify the ongoing pathological lipid breakdown and the state of parenchymal inflammation. The elevated LPC level in tissue suggests a means of intervention through lysophospholipid metabolism that could potentially benefit the management of stroke and other acute neurological injuries.
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PMID:Direct profiling of phospholipids and lysophospholipids in rat brain sections after ischemic stroke. 2055 94


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