Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P30044 (antioxidant enzyme)
 8,037 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Abnormalities in the cellular regulation and expression of antioxidant enzymes may have a role in mechanisms of central nervous system aging and neurodegeneration. We therefore examined, using isozyme-specific antibodies and immunohistochemistry, the localization of copper, zinc-superoxide dismutase and manganese-superoxide dismutase in the frontal and temporal neocortices and hippocampi of aged controls and individuals with Alzheimer's disease or Down's syndrome. Two different antibodies to copper, zinc-superoxide dismutase and one antibody to manganese-superoxide dismutase were evaluated by immunoblotting of homogenates of human brain before use in immunohistochemistry. The copper, zinc-superoxide dismutase antibodies recognized a single band of proteins at 16 kd. The manganese-superoxide dismutase antibody detected a single band of proteins at 25 kd. Immunohistochemically, copper, zinc-superoxide dismutase and manganese-superoxide dismutase immunoreactivities were localized predominantly to neocortical and hippocampal pyramidal neurons and scarcely seen in glial cells in controls. In Alzheimer's disease and Down's syndrome, the distributions and intensities of these two forms of superoxide dismutase immunoreactivities were different as compared with controls. Copper, zinc-superoxide dismutase was enriched in pyramidal neurons undergoing degeneration, whereas manganese-superoxide dismutase was more enriched in reactive astrocytes than in neurons. In senile plaques, copper, zinc-superoxide dismutase-positive globular structures were surrounded by astrocytes highly enriched in manganese-superoxide dismutase. By double label immunohistochemistry, some pyramidal neurons coexpressed superoxide dismutases and tau, and a few copper, zinc-superoxide dismutase-positive structures in senile plaques colocalized with tau. Amyloid cores, diffuse plaques, and microglia scarcely showed colocalization with superoxide dismutase-positive structures. The observed changes in the cellular localization of superoxide dismutases in neocortex and hippocampus in cases of Alzheimer's disease and Down's syndrome support a role for oxidative injury in neuronal degeneration and senile plaque formation. The differential localization of copper, zinc-superoxide dismutase and manganese-superoxide dismutase in cerebral sites of degeneration suggests that cellular responses to oxidative stress is antioxidant enzyme specific and cell type specific and that these two forms of superoxide dismutase may have different functions in antioxidant mechanisms.
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PMID:Localization of superoxide dismutases in Alzheimer's disease and Down's syndrome neocortex and hippocampus. 785 48

Amyloid beta-peptide has been demonstrated to be toxic for primary and clonal neuronal cell lines in vitro. Oxidative mechanisms have been implicated in this pathway at several points, including the aggregation of beta-amyloid necessary for cytotoxic activity, generation of radicals by the peptide itself, and intracellularly in response to toxic beta-amyloid peptides. Supporting an oxidative hypothesis are the observations that cells mount a stress response to beta-amyloid similar to that seen in response to oxidative stress and that they may be rescued from cytotoxicity by antioxidants, inhibitors of oxidative enzyme metabolism, and overexpression of antioxidant enzymes. Although the source(s) of the oxygen radicals has not yet been identified, altered antioxidant enzyme levels and oxidative by-products in Alzheimer's disease brain samples relate the in vitro studies to the human disease.
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PMID:Oxidative mechanisms in beta-amyloid cytotoxicity. 911 60

Oxidative stress has been suggested to be involved in the pathogenesis of neurodegenerative diseases, such as Alzheimer disease (AD) and Parkinson disease (PD). Heme oxygenase-1 (HO-1), a key enzyme in heme catabolism, also functions as an antioxidant enzyme. Here, we show that a (GT)n repeat in the human HO-1 gene promoter region is highly polymorphic, although no particular alleles are associated with AD or PD. This newly identified genetic marker should allow us to study the possible involvement of HO-1 in certain human diseases.
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PMID:Microsatellite polymorphism in the human heme oxygenase-1 gene promoter and its application in association studies with Alzheimer and Parkinson disease. 922 84

Oxidative stress is implicated in several pathologies such as AIDS, Alzheimer's disease, and Parkinson's disease, as well as in normal aging. As a model system to study the response of cells to oxidative insults, glutamate toxicity on a mouse nerve cell line, HT-22, was examined. Glutamate exposure kills HT-22 via a nonreceptor-mediated oxidative pathway by blocking cystine uptake and causing depletion of intracellular glutathione (GSH), leading to the accumulation of reactive oxygen species and, ultimately, apoptotic cell death. Several HT-22 subclones that are 10-fold resistant to exogenous glutamate were isolated and the mechanisms involved in resistance characterized. The expression levels of neither heat shock proteins nor apoptosis-related proteins are changed in the resistant cells. In contrast, the antioxidant enzyme catalase, but not glutathione peroxidase nor superoxide dismutase, is more highly expressed in the resistant than in the parental cells. In addition, the resistant cells have enhanced rates of GSH regeneration due to higher activities of the GSH metabolic enzymes gamma-glutamylcysteine synthetase and GSH reductase, and GSH S-transferases activities are also elevated. As a consequence of these alterations, the glutamate resistant cells are also more resistant to organic hydroperoxides and anticancer drugs that affect these GSH enzymes. These results indicate that resistance to apoptotic oxidative stress may be acquired by coordinated changes in multiple antioxidant pathways.
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PMID:Cellular mechanisms of resistance to chronic oxidative stress. 964 Dec 55

The effects of Huperzine A (HupA), a novel acetylcholinesterase inhibitor, on hydrogen peroxide (H2O2) induced cell lesion, level of lipid peroxidation and antioxidant enzyme activities were investigated in rat pheochromocytoma line PC12. Following a 6-h exposure of the cells to H2O2 (200 microM), a marked reduction in cell survival and activities of glutathione peroxidase and catalase, as well as increased production of malondialdehyde (MDA) were observed. Pretreatment of the cells with HupA (0.1-10.0 microM) prior to H2O2 exposure significantly elevated the cell survival and antioxidant enzyme activities and decreased the level of MDA. Our results indicated that in addition to its anticholinesterase effects, HupA had protective effects against free radical-induced cell toxicity, which might be beneficial for the treatment of Alzheimer's disease.
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PMID:Huperzine A protects rat pheochromocytoma cells against hydrogen peroxide-induced injury. 1056 2

The transcription factor nuclear factor kappaB (NF-kappaB) is moving to the forefront of the fields of apoptosis and neuronal plasticity because of recent findings showing that activation of NF-kappaB prevents neuronal apoptosis in various cell culture and in vivo models and because NF-kappaB is activated in association with synaptic plasticity. Activation of NF-kappaB was first shown to mediate antiapoptotic actions of tumor necrosis factor in cultured neurons and was subsequently shown to prevent death of various nonneuronal cells. NF-kappaB is activated by several cytokines and neurotrophic factors and in response to various cell stressors. Oxidative stress and elevation of intracellular calcium levels are particularly important inducers of NF-kappaB activation. Activation of NF-kappaB can interrupt apoptotic biochemical cascades at relatively early steps, before mitochondrial dysfunction and oxyradical production. Gene targets for NF-kappaB that may mediate its antiapoptotic actions include the antioxidant enzyme manganese superoxide dismutase, members of the inhibitor of apoptosis family of proteins, and the calcium-binding protein calbindin D28k. NF-kappaB is activated by synaptic activity and may play important roles in the process of learning and memory. The available data identify NF-kappaB as an important regulator of evolutionarily conserved biochemical and molecular cascades designed to prevent cell death and promote neuronal plasticity. Because NF-kappaB may play roles in a range of neurological disorders that involve neuronal degeneration and/or perturbed synaptic function, pharmacological and genetic manipulations of NF-kappaB signaling are being developed that may prove valuable in treating disorders ranging from Alzheimer's disease to schizophrenia.
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PMID:Roles of nuclear factor kappaB in neuronal survival and plasticity. 1064 95

Increasing evidence supports the role of reactive oxygen species (ROS) in the pathogenesis of Alzheimer's disease (AD). Both in vivo and in vitro studies demonstrate that thioredoxin (Trx) and thioredoxin reductase (TR), the enzyme responsible for reduction of oxidized Trx, have protective roles against cytotoxicity mediated by the generation of ROS. The present study measured levels of Trx protein and activities of TR in the brain in AD compared with control subjects, and evaluated the possible protective role of TR and Trx against amyloid beta-peptide (Abeta) toxicity in neuronal cultures. Analysis of Trx protein levels in 10 AD and 10 control subjects demonstrated a general decrease in all AD brain regions studied, with statistically significant decreases in the amygdala (p <.05), hippocampus/parahippocampal gyrus (p <.05), and marginally significant (p <.10) depletions in the superior and middle temporal gryi. Thioredoxin reductase activity levels were increased in all AD brain regions studied with statistically significant increases occurring in AD amygdala (p =.01) and cerebellum (p =.007). To investigate the protective effects of Trx and TR against Abeta-induced toxicity, primary hippocampal cultures were treated with Trx or TR in combination with toxic doses of Abeta. Treatment of cultures with Trx led to a statistically significant concentration-dependent enhancement in cell survival against Abeta-mediated toxicity as did treatment with TR. Together, these data suggest that, although TR is protective against Abeta-mediated toxicity, the increase observed in AD brain offers no protection due to the significant decrease in Trx levels. This decrease in the antioxidant Trx-TR system may contribute to the increased oxidative stress and subsequent neurodegeneration observed in the brain in AD.
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PMID:Decreased thioredoxin and increased thioredoxin reductase levels in Alzheimer's disease brain. 1069 54

The effects of huperzine A (HupA), a novel acetylcholinesterase inhibitor, on Abeta(25-35)-induced cell lesion, level of lipid peroxidation, antioxidant enzyme activities were investigated in the rat pheochromocytoma line PC12. Following a 48 h exposure of the cells to Abeta(25-35), a significant reduction in cell survival and activities of glutathione peroxidase (GSH-Px) and catalase (CAT), as well as increased production of malondialdehyde (MDA) and superoxide dismutase (SOD) were observed. Preincubation of the cells with HupA prior to Abeta(25-35) exposure elevated the cell survival and GSH-Px and CAT activities, and decreased the level of MDA and SOD activity. The results indicate that HupA has protective effects against Abeta-induced cell toxicity, which might be beneficial for the treatment of Alzheimer's disease.
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PMID:Protective effects of huperzine A on beta-amyloid(25-35) induced oxidative injury in rat pheochromocytoma cells. 1083 8

Manganese superoxide dismutase (MnSOD) is an antioxidant enzyme that reduces superoxide anion to hydrogen peroxide in cell mitochondria. MnSOD is overexpressed in normal aging brain and in various central nervous system disorders; however, the mechanisms mediating the upregulation of MnSOD under these conditions remain poorly understood. We previously reported that cysteamine (CSH) and other pro-oxidants rapidly induce the heme oxygenase-1 (HO-1) gene in cultured rat astroglia followed by late upregulation of MnSOD in these cells. In the present study, we demonstrate that antecedent upregulation of HO-1 is necessary and sufficient for subsequent induction of the MnSOD gene in neonatal rat astroglia challenged with CSH or dopamine, and in astroglial cultures transiently transfected with full-length human HO-1 cDNA. Treatment with potent antioxidants attenuates MnSOD expression in HO-1-transfected astroglia, strongly suggesting that intracellular oxidative stress signals MnSOD gene induction in these cells. Activation of this HO-1-MnSOD axis may play an important role in the pathogenesis of Alzheimer disease, Parkinson disease and other free radical-related neurodegenerative disorders. In these conditions, compensatory upregulation of MnSOD may protect mitochondria from oxidative damage accruing from heme-derived free iron and carbon monoxide liberated by the activity of HO-1.
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PMID:Role of heme oxygenase-1 in the regulation of manganese superoxide dismutase gene expression in oxidatively-challenged astroglia. 1094 21

Increased oxidative stress resulting from free radical damage to cellular function is associated with a number of neurodegenerative diseases, in particular with Alzheimer's disease (AD). The deposition of amyloid beta-peptide (Abeta), the major pathological hallmark for AD, has been suggested as the central disease-causing and disease-promoting event for the disease, and the pathological role of Abeta was partially mediated by oxidative stress. Here we compared the effects of huperzine A (HupA) and tacrine, two acetylcholinesterase (AChE) inhibitors available for AD, on Abeta-induced cell lesion, level of lipid peroxidation, and antioxidant enzyme activities in rat PC12 and primary cultured cortical neurons. Following exposure of both cells to different concentrations of an active fragment of Abeta, a marked reduction in cell survival and activities of glutathione peroxidase (GSH-Px) and catalase (CAT), as well as increased production of malondialdehyde (MDA) and superoxide dismutase (SOD), were observed. Pretreatment of the cells with HupA or tacrine (0.1-10 microM) prior to Abeta exposure significantly elevated the cell survival and GSH-Px and CAT activities and decreased the level of MDA. Both drugs have similar protection against Abeta insult. Our results indicate that HupA and tacrine exert neuroprotective effects against Abeta toxicity, which might be of importance and might contribute to their clinical efficacy for the treatment of AD.
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PMID:Huperzine A and tacrine attenuate beta-amyloid peptide-induced oxidative injury. 1095 26


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