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

alpha-Lipoic acid, which plays an essential role in mitochondrial dehydrogenase reactions, has recently gained considerable attention as an antioxidant. Lipoate, or its reduced form, dihydrolipoate, reacts with reactive oxygen species such as superoxide radicals, hydroxyl radicals, hypochlorous acid, peroxyl radicals, and singlet oxygen. It also protects membranes by interacting with vitamin C and glutathione, which may in turn recycle vitamin E. In addition to its antioxidant activities, dihydrolipoate may exert prooxidant actions through reduction of iron. alpha-Lipoic acid administration has been shown to be beneficial in a number of oxidative stress models such as ischemia-reperfusion injury, diabetes (both alpha-lipoic acid and dihydrolipoic acid exhibit hydrophobic binding to proteins such as albumin, which can prevent glycation reactions), cataract formation, HIV activation, neurodegeneration, and radiation injury. Furthermore, lipoate can function as a redox regulator of proteins such as myoglobin, prolactin, thioredoxin and NF-kappa B transcription factor. We review the properties of lipoate in terms of (1) reactions with reactive oxygen species; (2) interactions with other antioxidants; (3) beneficial effects in oxidative stress models or clinical conditions.
 ...
PMID:alpha-Lipoic acid as a biological antioxidant. 764 94

Adult T cell leukemia-derived factor (ADF) is a human homologue of thioredoxin (TRX) with many biological functions and is induced by various stimuli and stress. In the central nervous system (CNS), expression of ADF/TRX occurs in glial cells during ischemia and reperfusion. We showed that ADF/TRX was actively released from U251 astrocytoma cells upon exposure to a low concentration of H2O2. The addition of conditioned medium from H2O2-stimulated U251 cells or recombinant ADF (rADF) to the culture medium promoted the survival of neurons from embryonic mouse cortex and striatum, but the addition of mutant ADF (mADF), which has no reducing activity, did not. In addition to rADF, incubation with two other thiol compounds, 2-mercaptoethanol (2-ME) and N-acetyl-L-cysteine (NAC), also increased the neuronal cell survival rate. In contrast, L-buthionine-(S,R)-sulfoximine (BSO), which inhibited the synthesis of glutathione (GSH), decreased the neuronal cell survival rate. Intracellular GSH was increased by incubation with rADF for 24 h, as it is with 2-ME and NAC. Redox active molecules such as thiol compounds may be survival factors for central neurons in vitro, and this capacity may be supplied by endogenous molecules, such as ADF/TRX and glutathione, under certain pathologic conditions in vivo.
 ...
PMID:Neuroprotection by glial cells through adult T cell leukemia-derived factor/human thioredoxin (ADF/TRX). 795 44

Human thioredoxin, which was previously recognized as adult T-cell leukemia-derived factor, has many physiologic activities, one of which is a radical scavenger effect. Its ability to reduce reperfusion injury was assessed in vivo in a canine lung transplantation model. In 19 dogs, left lung allotransplantation was performed after 100 minutes of warm ischemia. The function of the transplanted lung was assessed after clamping of the contralateral pulmonary artery. In the human thioredoxin group (n = 6), human thioredoxin 30 mg/kg was given to the recipients during reperfusion. In the N-acetylcysteine group (n = 5), N-acetylcysteine 150 mg/kg, known as a radical scavenger, was given in the same manner. In both groups, arterial oxygen tension was significantly higher than in the control group (n = 8). In the human thioredoxin group, peak inspiratory pressure was significantly lower than in the control group. Macroscopic and microscopic examinations showed an almost normal appearance of the lung tissues in the human thioredoxin and N-acetylcysteine groups, in contrast to the abnormal findings in the control group. Thus it would appear that human thioredoxin has a protective effect on transplanted lungs, as does N-acetylcysteine, and that its action may be a radical scavenger effect.
 ...
PMID:Inhibition of reperfusion injury by human thioredoxin (adult T-cell leukemia-derived factor) in canine lung transplantation. 796 75

We studied the role of human thioredoxin and L-cysteine in ischemia-reperfusion lung injury. Thirty adult Wistar rats were allocated to five groups, according to the drug added to the pulmonary artery flush solution before ischemia (groups 1 and 2: none; group 3: human thioredoxin; group 4: L-cysteine, and group 5: human thioredoxin and L-cysteine) and according to the ex vivo ischemic interval at 37 degrees C (group 1: no ischemia; groups 2-5: 90 min). After ischemia, the lungs were reperfused for 60 min with Krebs-Henseleit solution containing 4% bovine serum albumin. In nonischemic lungs, the pulmonary arterial pressure, airway pressure, wet to dry lung weight ratio and the albumin concentration in bronchoalveolar fluid were within normal ranges. In contrast, all parameters of ischemic untreated lungs were generally poor. Compared to the ischemic untreated lungs, treatment with the combination of human thioredoxin and L-cysteine significantly reduced the wet to dry lung weight ratio (group 2: 9.18 +/- 0.25, group 5: 7.88 +/- 0.27), and the albumin concentration in the bronchoalveolar lavage fluid (group 2: 78.3 +/- 17.1 micrograms/ml, group 5: 24.0 +/- 3.8 micrograms/ml). No significant improvement was found in pulmonary arterial pressure and airway pressure. These results suggested that treatment with human thioredoxin (adult T cell leukemia-derived factor) and L-cysteine attenuates ischemia-reperfusion injury in isolated rat lungs.
 ...
PMID:Effect of the combination of human thioredoxin and L-cysteine on ischemia-reperfusion injury in isolated rat lungs. 854 21

Adult T-cell leukemia-derived factor (ADF), identified in the supernatant of adult T-cell leukemia (ATL) cell culture, is a human homologue of thioredoxin and consists of 104 amino acids; it has two redox-active half-cysteine residues in an exposed active center. Human thioredoxin has many biological activities, including growth promotion, cell activation, and a catalase-like radical scavenging activity. We examined the protective effect of human thioredoxin (h-thioredoxin) against reperfusion-induced arrhythmias in an isolated rat heart model with 10-min regional ischemia followed by 30-min reperfusion. Male Wistar rats were assigned to six groups: a control, a superoxide dismutase (SOD 8 x 10(4) IU/L), and a catalase group (1 x 10(6) IU/L), and three groups treated with h-thioredoxin [approximately .01 microM (TRX-I group), approximately 0.1 microM (TRX-II group), and approximately 1 microM (TRX-III group)]. In the early reperfusion period, h-thioredoxin reduced the incidence of ventricular fibrillation (VF) to 8% in the TRX-II group (p < 0.01) from the control value of 75%. SOD and catalase reduced the incidence of VF to 43 and 33%, respectively (NS). During the entire reperfusion period, the incidence of VF in the SOD group was 79%, as compared to 83% in the control group. In the catalase and TRX-II groups, the incidence of VF was significantly reduced to 42 and 25%, respectively. These findings indicate that SOD failed to protect against the reperfusion-induced arrhythmias. h-Thioredoxin exerted a protective effect against these arrhythmias; a concentration of approximately 0.1 micro was the most effective.
 ...
PMID:Protection against reperfusion-induced arrhythmias by human thioredoxin. 885 44

Prostaglandin E1 (PGE1) is commonly used in therapy for obstructive diseases, including ischemic retinopathy, in which pathogenetic reactive oxygen intermediates are responsible. However, the mechanism(s) of PGE1 in reducing tissue damage is still unclear. Adult T-cell leukemia-derived factor/human thioredoxin (ADF) is induced by oxidative stresses and has protective activity against oxidative cellular injury. To evaluate the possible involvement of ADF in the tissue-protective effect of PGE1, we analyzed ADF expression immunohistochemically using a rat transient retinal ischemia model. Rats were treated orally with 300 micrograms/kg/day OP-1206 alpha-cyclodextrin clathrate (OP-1206), a stable PGE1 analogue, for 14 days after photodynamic retinal vascular thrombosis by rose Bengal. Rats without any OP-1206 treatment were used as controls. In the OP-1206-treated rats, minimal retinal atrophy due to ischemia/reperfusion was observed histologically up to 14 days, whereas in the non-treated rats the inner layer of the retina became markedly atrophic. In parallel with the histological change, after 14 days following thrombosis ADF immunoreactivity was preserved on retinal pigment epithelial cells in the OP-1206-treated rats, whereas it was diminished in the non-treated rats. These findings suggest an important role for ADF in the OP-1206-dependent suppression of retinal tissue damage caused by oxidative insult.
 ...
PMID:Analysis of localization of adult T-cell leukemia-derived factor in the transient ischemic rat retina after treatment with OP-1206 alpha-CD, a prostaglandin E1 analogue. 901 Apr 70

Human thioredoxin is a polypeptide with thiol groups, possessing reducing activity, which is proved to have the ability to reduce active oxygens. This study evaluated the effect of human thioredoxin on the ischemia-reperfusion lung injury and the roles of human thioredoxin on active oxygens by chemiluminescence examination. The left hilum of the lung of Japanese white rabbits was occluded for 110 minutes and then reperfused for 90 minutes. Ten, 30, 60, and 90 minutes after reperfusion the right hilum was occluded for 5 minutes and the pulmonary functions of the left lung were examined. The animals were divided into four groups, three ischemia groups and a sham group (without occlusion; n = 6). The ischemia groups received human thioredoxin, 60 mg/kg (n = 10), N-acetylcysteine, 150 mg/kg (n = 7), or saline solution (control, n = 10) during reperfusion. Three rabbits in the human thioredoxin group and the control group were used to measure active oxygens with a cypridina luciferin analog. An additional group of reperfused lungs (n = 3) that were given superoxide dismutase after 110 minutes of ischemia was established to identify chemiluminescence examination. Compared with the sham group, reperfusion after 110 minutes of ischemia produced a significant lung injury in the control group. Among the ischemia groups, the human thioredoxin group showed significantly higher arterial oxygen tension at 30, 60, and 90 minutes after reperfusion than the control group, although there was no significant difference between the N-acetylcysteine and control groups. Histologically, intraalveolar exudation, interstitial thickening, and cellular infiltration were seen in the control group, whereas in the thioredoxin group alveolar structure was well preserved. In the measurement of active oxygens the chemiluminescence in the human thioredoxin group was less than that in the control group and as little as that in the group administered superoxide dismutase. We concluded human thioredoxin attenuated ischemia-reperfusion injury by involving active oxygens in rabbit lungs.
 ...
PMID:Amelioration of ischemia-reperfusion injury by human thioredoxin in rabbit lung. 901 76

According to their demonstrated activities, the thiol-disulfide oxidoreductase (TDOR) enzyme systems [thioltransferase (glutaredoxin) and GSSG reductase; and thioredoxin and thioredoxin reductase] are expected to provide the primary cellular mechanism for protection and repair of sulfhydryl proteins under oxidative stress. Since all four enzymes have active site dithiol moieties, they may be vulnerable to oxidative damage themselves. Therefore, an hydroxyl radical generating system (chelated ferrous iron in combination with hydrogen peroxide) was used to document the relative sensitivity of each of the enzymes to oxidative stress in vitro. At particular concentrations of enzymes and oxidant system, all of the enzymes were deactivated nearly completely, but different patterns of susceptibility were observed. At the approximate physiological concentration of each enzyme thioredoxin and thiol-transferase were largely deactivated with 1 mM Fe2+-ADP, 1 mM H2O2; whereas thioredoxin reductase and GSSG reductase were much less sensitive: 10 microM thioredoxin (88% deactivated), 1 microM thioltransferase (72%), 2 microM thioredoxin reductase (5%), and 0.1 microM GSSG reductase (17%). As the concentration of the oxidant system was decreased stepwise from 1 mM to 1 microM to mimic conditions that may be associated with oxidative tissue injury in situ, deactivation of thioredoxin was decreased proportionately, whereas thioltransferase remained much more susceptible. As expected GSH and other radical scavengers protected thioltransferase from deactivation by Fe(ADP)-H2O2. To test the susceptibility of the TDOR enzymes to oxidative stress in a physiological-like setting, isolated perfused rabbit hearts were subjected to 30 min ischemia and 30 min reperfusion. The GSH/GSSG ratio and total dethiolase activity (thioltransferase and thioredoxin systems) remained unchanged relative to control hearts, indicating that overall redox status and sulfhydryl repair activity are maintained during moderate oxidative stress in situ.
 ...
PMID:Sensitivity of protein sulfhydryl repair enzymes to oxidative stress. 921 73

We assayed redox regulatory protein, thioredoxin (TRX) and TRX mRNA in the rat brain after transient and permanent middle cerebral artery (MCA) occlusion. The immunoreactivity for TRX and TRX mRNA disappeared after MCA occlusion in the ischemic core regions. On the other hand, in the perifocal ischemic regions, TRX immunoreactivity and TRX mRNA was enhanced. In addition, in transient MCA occlusion, TRX induction was stronger in the hippocampus and more widespread in the contralateral cortex than in permanent occlusion. Moreover, the induced TRX was translocated into the cellular nucleus after ischemia and ischemia-reperfusion. These results suggest that TRX induction was accompanied with reactive oxygen intermediates (ROI) overproduction and may play an important role not only in scavenging ROI but also in signal transduction during ischemia.
 ...
PMID:Expression and distribution of redox regulatory protein, thioredoxin during transient focal brain ischemia in the rat. 971 56

The adult T cell leukemia-derived factor (ADF), or human thioredoxin (hTRX), has a radical scavenging effect similar to that of N-acetyl cysteine (NAC). We have recently shown that ADF/hTRX protects the lung and the heart from ischemia-reperfusion induced injury. To elucidate mechanisms of the protective effect, a hypoxia-reoxygenation (H-R) injury model was developed using a murine endothelial cell line, cultured in a thiol-free medium. In this condition, cells became much more vulnerable to H-R injury. The viability of cells decreased significantly after 1 h of hypoxic incubation followed by 1 h of reoxygenation. The injury was reduced by ADF/hTRX (100 microM) or NAC (10 mM). These two agents also demonstrated an additive protective effect. When cells were cultured in thiol-free medium for 2 h in a normoxic condition, intracellular hydrogen peroxide production was increased, which was associated with a decrease in glutathione level. NAC (10 mM) attenuated these changes whereas ADF/hTRX (100 microM) did not. These results suggest that although both ADF/hTRX and NAC protected cells from H-R injury, the underlying mechanisms are different. Because the cytoprotective effect of ADF/hTRX occurs in the thiol-free condition, it must be mediated via a novel mechanism other than enhancing thiol uptake. The additive cytoprotective effect between ADF/hTRX and NAC suggests that we should combine these two agents clinically.
 ...
PMID:Human thioredoxin attenuates hypoxia-reoxygenation injury of murine endothelial cells in a thiol-free condition. 1056 14


1 2 3 4 5 6 7 8 9 10 Next >>