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)

The antioxidant enzyme Cu,Zn superoxide dismutase (SOD1) is predominantly localized in the cytosol, but it is also found in mitochondria. Studies in yeast suggest that apoSOD1 is imported into mitochondria and trapped inside by folding and maturation, which is facilitated by its copper chaperone for SOD1 (CCS). Here, we show that in mammalian cells, SOD1 mitochondrial localization is dictated by its folding state, which is modulated by several interconnected factors. First, the intracellular distribution of CCS determines SOD1 partitioning in cytosol and mitochondria: CCS localization in the cytosol prevents SOD1 mitochondrial import, whereas CCS in mitochondria increases it. Second, the Mia40/Erv1 pathway for import of small intermembrane space proteins participates in CCS mitochondrial import in a respiratory chain-dependent manner. Third, CCS mitochondrial import is regulated by oxygen concentration: high (20%) oxygen prevents import, whereas physiological (6%) oxygen promotes it. Therefore, SOD1 localization responds to changes in environmental conditions following redistribution of CCS, which operates as an oxygen sensor. Fourth, all of the cysteine residues in human SOD1 are critical for its retention in mitochondria due to their involvement in intramolecular disulfide bonds and in the interaction with CCS. Mutations in SOD1 are associated with autosomal dominant familial amyotrophic lateral sclerosis. Like the wild-type protein, mutant SOD1 localizes to mitochondria, where it induces bioenergetic defects. We find that the physiological regulation of mitochondrial localization is either inefficient or absent in SOD1 pathogenic mutants. We propose misfolding and aggregation of these mutants that trap them inside mitochondria.
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PMID:Different regulation of wild-type and mutant Cu,Zn superoxide dismutase localization in mammalian mitochondria. 1870 98

Mitochondrial dysfunction and oxidative stress are thought to participate in the pathogenesis of amyotrophic lateral sclerosis (ALS). The purpose of this study was to determine the effect of reduced mitochondrial antioxidant defense on lifespan and disease progression in two mouse models of familial ALS (G93A and H46R/H48Q mutant lines) that represent pseudo-wildtype and metal-deficient ALS mutants, respectively. The metal-deficient H46R/H48Q mutant differs from the G93A mutant in that it cannot bind copper in the active site and thus lacks SOD activity. We crossed each of these mutant lines with mice deficient in the mitochondrial matrix antioxidant enzyme MnSOD (Sod2+/- mice). In both high (G93A1Gur) and low (G93ADL) copy G93A strains, MnSOD deficiency caused a decrease in lifespan that was associated with a reduced disease duration rather than earlier disease onset. In contrast, MnSOD deficiency had no effect on lifespan or disease parameters of H46R/H48Q mutant mice. MnSOD deficiency thus has a differential effect on disease progression in different mutant SOD1 ALS mouse models, suggesting that different ALS-causing mutations in SOD1 result in disease progression by at least proximally different mechanisms/pathways.
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PMID:MnSOD deficiency has a differential effect on disease progression in two different ALS mutant mouse models. 1872 May 9

Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease, selectively involving the upper and lower motor neurons. Glutamate excitotoxicity and oxidative stress are important mechanisms for the pathogenesis of ALS. Nuclear-factor erythroid 2-related factor 2 (Nrf2) is a master transcriptional regulator of many cytoprotective genes. Nrf2 signal pathway could induce a series of antioxidant enzyme, anti-inflammatory and antitoxic protein. The expression of these antioxidant enzymes and antioxidant proteins in nervous system exhibited broad neuroprotection against injury by glutamate. Diallyl trisulfide (DATS) was previously shown to induce many Nrf2 target genes in non-nervous cells. Our studies have shown that DATS at 50 microM caused activation of Nrf2 and Nrf2 target gene in rat spinal cord explants. DATS also protected motor neurons against glutamate-induced excitotoxicity. These have identified DATS as a promising neuroprotective agent and suggest that the activation of Nrf2 signal pathway may be a new strategy in neurodegeneration disease.
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PMID:Neuroprotective potential of phase II enzyme inducer diallyl trisulfide. 1876 14

The antioxidant enzyme superoxide dismutase 1 (SOD1) is a critical player of the antioxidative defense whose activity is altered in several chronic diseases, including amyotrophic lateral sclerosis. However, how oxidative insult affects muscle homeostasis remains unclear. This study addresses the role of oxidative stress on muscle homeostasis and function by the generation of a transgenic mouse model expressing a mutant SOD1 gene (SOD1(G93A)) selectively in skeletal muscle. Transgenic mice developed progressive muscle atrophy, associated with a significant reduction in muscle strength, alterations in the contractile apparatus, and mitochondrial dysfunction. The analysis of molecular pathways associated with muscle atrophy revealed that accumulation of oxidative stress served as signaling molecules to initiate autophagy, one of the major intracellular degradation mechanisms. These data demonstrate that skeletal muscle is a primary target of SOD1(G93A) -mediated toxicity and disclose the molecular mechanism whereby oxidative stress triggers muscle atrophy.
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PMID:Skeletal muscle is a primary target of SOD1G93A-mediated toxicity. 1904 73

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease caused by the degeneration of motor neurons. Mutations in Cu/Zn superoxide dismutase (SOD1), including G93A, were reportedly linked to familial ALS. SOD1 is a key antioxidant enzyme, and is also one of the major targets for oxidative damage in the brains of patients suffering from Alzheimers disease (AD). Several lines of evidence suggest that intracellular amyloid beta (Abeta) is associated with the pathogenesis of AD. In this report we demonstrate that intracellular Abeta directly interacts with SOD1, and that this interaction decreases the enzymatic activity of the enzyme. We observed Abeta-SOD1 aggregates in the perinuclear region of H4 cells, and mapped the SOD1 binding region to Abeta amino acids 26-42. Interestingly, intracellular Ab binds to the SOD1 G93A mutant with greater affinity than to wild-type SOD1. This resulted in considerably less mutant enzymatic activity. Our study implicates a potential role for Abeta in the development of ALS by interacting with the SOD1 G93A mutant.
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PMID:Intracellular amyloid beta interacts with SOD1 and impairs the enzymatic activity of SOD1: implications for the pathogenesis of amyotrophic lateral sclerosis. 1947 59

Research increasingly suggests that enantiomer selectivity may be a part of the toxicological effects of chiral contaminants. In this study, we selected Japonica rice variety Xiushui 63 seedlings to evaluate the enantioselectivity of imazethapyr (IM). Significant differences in rice seedling morphology, antioxidant enzyme, oxidant marker and gene transcription were observed between the two IM enantiomers. In the seedling morphological assay, IM enantiomers inhibited elongation of primary roots and shoots, and reduced the number of adventitious roots and the density of root hairs. The inhibitory effects were enhanced with increasing concentrations of IM. The maximal root relative inhibition rate reached 80.4%, 67.0%, and 73.5% for R-(-)-IM, S-(+)-IM and racemate at the concentration of 0.5 mg L(-1), respectively, and the maximal shoot relative inhibition rate reached 77.7%, 26.9%, and 61.7%, respectively. The activities of SOD, POD and CAT and the content of MDA increased at 0.5 mg L(-1) of R-(-)-IM treatment, and were 1.8, 3.3, 1.4, and 2.2 times, respectively, over the activities S-(+)-IM. Real-time PCR showed that R-(-)-IM minimized the transcript abundance of ALS in shoot tissue to 12.2% of the S-(+)-IM, and minimized the transcript abundance of PC in seed to 9.2% of the S-(+)-IM. R-(-)-IM maximized the transcript abundance of beta-amylase in shoots to 8.6-time of the S-(+)-IM. Results from this study imply that R-(-)-IM has stronger toxicity on the growth of rice than S-(+)-IM.
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PMID:Enantioselective phytotoxicity of the herbicide imazethapyr in rice. 1950 84

Amyotrophic lateral sclerosis (ALS) is a devastating neurodegenerative disorder characterized by death of motor neurons leading to muscle wasting, paralysis, and death, usually within 2-3 years of symptom onset. The causes of ALS are not completely understood, and the neurodegenerative processes involved in disease progression are diverse and complex. There is substantial evidence implicating oxidative stress as a central mechanism by which motor neuron death occurs, including elevated markers of oxidative damage in ALS patient spinal cord and cerebrospinal fluid and mutations in the antioxidant enzyme superoxide dismutase 1 (SOD1) causing approximately 20% of familial ALS cases. However, the precise mechanism(s) by which mutant SOD1 leads to motor neuron degeneration has not been defined with certainty, and the ultimate trigger for increased oxidative stress in non-SOD1 cases remains unclear. Although some antioxidants have shown potential beneficial effects in animal models, human clinical trials of antioxidant therapies have so far been disappointing. Here, the evidence implicating oxidative stress in ALS pathogenesis is reviewed, along with how oxidative damage triggers or exacerbates other neurodegenerative processes, and we review the trials of a variety of antioxidants as potential therapies for ALS.
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PMID:Oxidative stress in ALS: key role in motor neuron injury and therapeutic target. 1996 67

Cu,Zn superoxide dismutase (SOD1) is an antioxidant enzyme that catalyzes the removal of superoxide radicals generated in various biological oxidations. Amyotrophic lateral sclerosis (ALS) is one of the most common neurodegenerative disorders, occurring in families (FALS) and sporadically (SALS). FALS and SALS are distinguishable genetically but not clinically. More than 100 point mutations in the human SOD 1 gene have been identified that cause FALS. In order to determine the effects of mutant SOD protein, we first cloned wild-type and A4V mutant human SOD1 into Schizosaccharomyces pombe. This study shows viabilities and some antioxidant properties including SOD, catalase, proteasomal activity, and protein carbonyl levels of transformants in SOD1 deleted strain (MN415); and its parental strain (JY741) at different stress conditions. There was no more oxidative damage in the human mutant SOD carrying the transformant strain compared with other strains. These results may help to explain whether ALS progresses as a consequence of cellular oxidative damage.
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PMID:Expression of human A4V mutant Cu,Zn superoxide dismutase in Schizosaccharomyces pombe: investigations of its toxic properties. 2009 44

Caloric restriction (CR) extends lifespan through a reduction in oxidative stress, delays the onset of morbidity and prolongs lifespan. We previously reported that long-term CR hastened clinical onset, disease progression and shortened lifespan, while transiently improving motor performance in G93A mice, a model of amyotrophic lateral sclerosis (ALS) that shows increased free radical production. To investigate the long-term CR-induced pathology in G93A mice, we assessed the mitochondrial bioenergetic efficiency and oxidative capacity (CS--citrate synthase content and activity, cytochrome c oxidase--COX activity and protein content of COX subunit-I and IV and UCP3-uncoupling protein 3), oxidative damage (MDA--malondialdehyde and PC--protein carbonyls), antioxidant enzyme capacity (Mn-SOD, Cu/Zn-SOD and catalase), inflammation (TNF-alpha), stress response (Hsp70) and markers of apoptosis (Bax, Bcl-2, caspase 9, cleaved caspase 9) in their skeletal muscle. At age 40 days, G93A mice were divided into two groups: Ad libitum (AL; n = 14; 7 females) or CR (n = 13; 6 females), with a diet equal to 60% of AL. COX/CS enzyme activity was lower in CR vs. AL male quadriceps (35%), despite a 2.3-fold higher COX-IV/CS protein content. UCP3 was higher in CR vs. AL females only. MnSOD and Cu/Zn-SOD were higher in CR vs. AL mice and CR vs. AL females. MDA was higher (83%) in CR vs. AL red gastrocnemius. Conversely, PC was lower in CR vs. AL red (62%) and white (30%) gastrocnemius. TNF-alpha was higher (52%) in CR vs. AL mice and Hsp70 was lower (62%) in CR vs. AL quadriceps. Bax was higher in CR vs. AL mice (41%) and CR vs. AL females (52%). Catalase, Bcl-2 and caspases did not differ. We conclude that CR increases lipid peroxidation, inflammation and apoptosis, while decreasing mitochondrial bioenergetic efficiency, protein oxidation and stress response in G93A mice.
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PMID:Caloric restriction shortens lifespan through an increase in lipid peroxidation, inflammation and apoptosis in the G93A mouse, an animal model of ALS. 2019 68

A mutant form of the copper/zinc superoxide dismutase (SOD1) protein is found in some patients with amyotrophic lateral sclerosis (ALS). Alteration of the activity of this antioxidant enzyme leads to an oxidative stress imbalance, which damages the structure of lipids and proteins in the CNS. Using fluorescence spectroscopy, we monitored membrane fluidity in the spinal cord and the brain in a widely used animal model of ALS, the SOD(G93A) mouse, which develops symptoms similar to ALS with an accelerated course. Our results show that the membrane fluidity of the spinal cord in this animal model significantly decreased in symptomatic animals compared with age-matched littermate controls. To the best of our knowledge, this is the first report showing that membrane fluidity is affected in the spinal cord of a SOD(G93A) animal model of ALS. Changes in membrane fluidity likely contribute substantially to alterations in cell membrane functions in the nervous tissue from SOD(G93A) mice.
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PMID:Levels of membrane fluidity in the spinal cord and the brain in an animal model of amyotrophic lateral sclerosis. 2145 79


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