Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0002736 (amyotrophic lateral sclerosis)
 19,048 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This overview summarizes recent findings on the role of tyrosyl radical (TyrO(*)) in the multitudinous neurochemical systems of brain, and theorizes on the putative role of TyrO(*) in neurological disorders [Parkinson's disease (PD), Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS)]. TyrO(*) and tyrosine per se can interact with reactive oxygen species (ROS) and reactive nitrogen species (RNS) via radical mechanisms and chain propagating reactions. The concentration of TyrO(*), ROS and RNS can increase dramatically under conditions of generalized stress: oxidative, nitrative or reductive as well, and this can induce damage directly (by lipid peroxidation) or indirectly (by proteins oxidation and/or nitration), potentially causing apoptotic neuronal cell death or autoschizis. Evidence of lesion-induced neuronal oxidative stress includes the presence of protein peroxides (TyrOOH), DT (o,o'-dityrosine) and 3-NT (3-nitrotyrosine). Mechanistic details of protein- and enzymatic oxidation/nitration in vivo remain unresolved, although recent in vitro data strongly implicate free radical pathways via TyrO(*). Nitration/denitration processes can be pathological, but they also may play: 1). a signal transduction role, because nitration of tyrosine residues through TyrO(*) formation can modulate, as well the phosphorylation (tyrosine kinases activity) and/or tyrosine hydroxylation (tyrosine hydroxylase inactivation), leading to consequent dopamine synthesis failure and increased degradation of target proteins, respectively; 2). a role of "blocker" for radical-radical reactions (scavenging of NO(*), NO(*)(2) and CO(3)(*-) by TyrO(*)); 3). a role of limiting factors for peroxynitrite formation, by lowering O(2)(*-) formation, which is strongly linked to the pathogenesis of neural diseases. It is still not known if tyrosine oxidation/nitration via TyrO(*) formation is 1). a footprint of generalized stress and neuronal disorders, or 2). an important part of O(2)(*-) and NO(*) metabolism, or 3). merely a part of integral processes for maintaining of neuronal homeostasis. The full answer to these questions should be of top research priority, as the problem of increased free radical formation in brain and/or imbalance of the ratios ROS/RNS/TyrO(*) may be all important in defining whether oxidative stress is the critical determinant of tissue and neural cell injury that leads to pathological end-points.
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PMID:Submolecular adventures of brain tyrosine: what are we searching for now? 1237 23

Oxidative damage, produced by mutant Cu/Zn superoxide dismutase (SOD1), may play a role in the pathogenesis of amyotrophic lateral sclerosis (ALS), a devastating motor neuron degenerative disease. A novel approach to antioxidant therapy is the use of metalloporphyrins that catalytically scavenge a wide range of reactive oxygen and reactive nitrogen species. In this study, we examined the therapeutic potential of iron porphyrin (FeTCPP) in the G93A mutant SOD1 transgenic mouse model of ALS. We found that intraperitoneal injection of FeTCPP significantly improved motor function and extended survival in G93A mice. Similar results were seen with a second group of mice wherein treatment with FeTCPP was initiated at the onset of hindlimb weakness-roughly equivalent to the time at which treatment would begin in human patients. FeTCPP-treated mice also showed a significant reduction in levels of malondialdehyde (a marker of lipid peroxidation), in total content of protein carbonyls (a marker of protein oxidation), and increased neuronal survival in the spinal cord. These results therefore provide further evidence of oxidative damage in a mouse model of ALS, and suggest that FeTCPP could be beneficial for the treatment of ALS patients.
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PMID:Iron porphyrin treatment extends survival in a transgenic animal model of amyotrophic lateral sclerosis. 1264 36

Nitration of tyrosine in biological conditions represents a pathological event that is associated with several neurodegenerative diseases, such as amyotrophic lateral sclerosis, Parkinson's disease and Alzheimer's disease (AD). Increased levels of nitrated proteins have been reported in AD brain and CSF, demonstrating the potential involvement of reactive nitrogen species (RNS) in neurodegeneration associated with this disease. Reaction of NO with O2- leads to formation of peroxynitrite ONOO-, which following protonation, generates cytotoxic species that oxidize and nitrate proteins. Several findings suggest an important role of protein nitration in modulating the activity of key enzymes in neurodegenerative disorders, although extensive studies on specific targets of protein nitration in disease are still missing. The present investigation represents a further step in understanding the relationship between oxidative modification of protein and neuronal death in AD. We previously applied a proteomics approach to determine specific targets of protein oxidation in AD brain, by successfully coupling immunochemical detection of protein carbonyls with two-dimensional polyacrylamide gel electrophoresis and mass spectrometry analysis. In the present study, we extend our investigation of protein oxidative modification in AD brain to targets of protein nitration. The identification of six targets of protein nitration in AD brain provides evidence to the importance of oxidative stress in the progression of this dementing disease and potentially establishes a link between RNS-related protein modification and neurodegeneration.
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PMID:Proteomic identification of nitrated proteins in Alzheimer's disease brain. 1278 59

Although oxygen is required for the energy metabolism in aerobic organisms, it generates reactive oxygen and nitrogen species that impair a wide variety of biological molecules, including lipids, proteins, and DNA, thereby causing various diseases. Because mitochondria are the major site of free radical generation, they are highly enriched with enzymes, such as Mn-type superoxide dismutase in matrix, and antioxidants including GSH on both sides of inner membranes, thus minimizing oxidative stress in and around this organelle. We recently showed that a cross talk of nitric oxide and oxygen radicals regulates the circulation, energy metabolism, reproduction, and remodeling of cells during embryonic development, and functions as a major defense system against pathogens. The present work shows that Cu/Zn-type superoxide dismutase, which has been postulated for a long time to be a cytosolic enzyme, also localizes bound to inner membranes of mitochondria, thereby minimizing oxidative stress in and around this organelle, while mitochondrial association decreases markedly with the variant types of the enzyme found in patients with familial amyotrophic lateral sclerosis. We also report that a cross talk of nitric oxide, superoxide, and molecular oxygen cooperatively regulates the fates of pathogens and their hosts and that oxidative stress in and around mitochondria also determines cell death in the development of animals and tissue injury caused by anticancer agents by some carnitine-inhibitable mechanism.
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PMID:Cross talk of nitric oxide, oxygen radicals, and superoxide dismutase regulates the energy metabolism and cell death and determines the fates of aerobic life. 1367 36

Reactive oxygen and nitrogen species (ROS and RNS) have been extensively recognized as important signaling molecules implicated in physiological processes such as gene expression, cell differentiation and immune activation. Nevertheless, continuous production of these species may produce oxidative and/or nitrosative stress resulting in cell damage and ultimately leading to cell death. Due to the high oxygen consumption and relative poor antioxidant defense, the central nervous system is highly susceptible to ROS- and RNS-mediated toxicity. Actually, the oxidative and nitrosative stress have been implicated in the pathogenesis of neurodegeneration of a large variety of neurological disorders. This review will cover some aspects of the involvement of ROS- and RNS-mediated apoptotic processes occurring in cellular models of familial amyotrophic lateral sclerosis (FALS), in particular the cases associated with mutations in SOD1, the gene encoding Cu,Zn superoxide dismutase (Cu,Zn SOD). A possible role for proteasome in the inhibition of neurodegenerative process by balancing ROS and RNS species is envisaged on the basis of evidence provided by results obtained from studies on this experimental model.
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PMID:Interplay of Cu,Zn superoxide dismutase and nitric oxide synthase in neurodegenerative processes. 1471 Oct 10

Oxidative stress is now recognized as accountable for redox regulation involving reactive oxygen species (ROS) and reactive nitrogen species (RNS). Its role is pivotal for the modulation of critical cellular functions, notably for neurons astrocytes and microglia, such as apoptosis program activation, and ion transport, calcium mobilization, involved in excitotoxicity. Excitotoxicity and apoptosis are the two main causes of neuronal death. The role of mitochondria in apoptosis is crucial. Multiple apoptotic pathways emanate from the mitochondria. The respiratory chain of mitochondria that by oxidative phosphorylation, is the fount of cellular energy, i.e. ATP synthesis, is responsible for most of ROS and notably the first produced, superoxide anion (O(2)(;-)). Mitochondrial dysfunction, i.e. cell energy impairment, apoptosis and overproduction of ROS, is a final common pathogenic mechanism in aging and in neurodegenerative disease such as Alzheimer's disease (AD), Parkinson's disease (PD) and amyotrophic lateral sclerosis (ALS). Nitric oxide (NO(;)), an RNS, which can be produced by three isoforms of NO-synthase in brain, plays a prominent role. The research on the genetics of inherited forms notably ALS, AD, PD, has improved our understanding of the pathobiology of the sporadic forms of neurodegenerative diseases or of aging of the brain. ROS and RNS, i.e. oxidative stress, are not the origin of neuronal death. The cascade of events that leads to neurons, death is complex. In addition to mitochondrial dysfunction (apoptosis), excitotoxicity, oxidative stress (inflammation), the mechanisms from gene to disease involve also protein misfolding leading to aggregates and proteasome dysfunction on ubiquinited material.
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PMID:Neurodegenerative diseases and oxidative stress. 1473 60

Nitric oxide (nitrogen monoxide; NO) is a simple molecule with diverse biological functions. NO and related reactive nitrogen oxide species (RNOS) mediate intricate physiological and pathophysiological effects in the central nervous system. Depending on environmental conditions, NO and RNOS can initiate and mediate neuroprotection or neurotoxicity either exclusively or synergistically with other effectors. The focus of this review is limited to the neuroprotectant/neurotoxic role of NO in Acquired Immune Deficiency Syndrome (AIDS) Dementia Complex (aka HIV--Associated Dementia; HAD) Amyotrophic Lateral Sclerosis (aka Lou Gehrig's Disease), Alzheimer's Disease, Huntington's Disease, Multiple Sclerosis and Parkinson's Disease. This review will shed light on the question: "How important is NO in neurodegenerative diseases?"
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PMID:Nitric oxide neurotoxicity in neurodegenerative diseases. 1476 6

Peroxynitrite-dependent tyrosine nitration has been postulated to be involved in motor neuron degeneration in amyotrophic lateral sclerosis (ALS). Evidence supporting this supposition includes the appearance of both free and protein-linked 3-nitro-l-tyrosine (nitrotyrosine) in both sporadic and familial ALS, as well as of increased free nitrotyrosine levels in the spinal cord of transgenic mice expressing ALS-linked superoxide dismutase mutants at symptom onset. Here we demonstrate that incubation with clinically relevant concentrations of nitrotyrosine induced apoptosis in motor neurons cultured with trophic factors. Nitrotyrosine was bound to proteins, but it was not incorporated into alpha-tubulin, as previously demonstrated for other cell types. Neither inhibition of nitric oxide production nor scavenging of superoxide and peroxynitrite prevented increases in cell nitrotyrosine immunoreactivity or motor neuron death, suggesting that these effects are not due to the endogenous formation of reactive nitrogen species. In contrast, some populations of astrocytes incorporated nitrotyrosine into alpha-tubulin, but free nitrotyrosine had no effect on the viability and phenotype of astrocytes in culture, as evaluated by glial fibrillary acidic protein immunoreactivity, cell growth and morphology. Co-culture of motor neurons on astrocyte monolayers delayed, but did not prevent, nitrotyrosine-induced motor neuron death. These results suggest that free nitrotyrosine may play a role in the induction of motor neuron apoptosis in ALS.
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PMID:Induction of motor neuron apoptosis by free 3-nitro-L-tyrosine. 1508 17

Many neurological diseases, including Alzheimer's disease (AD) and amyotrophic lateral sclerosis (ALS), are now recognized to share atypical inflammatory reactions as a major pathological feature. Neuroinflammation can both be a cause, and a consequence, of chronic oxidative stress. Cytokine-stimulated microglia generate copious amounts of reactive oxygen and reactive nitrogen species, creating a stress upon ambient neurons. Conversely, oxidants can stimulate pro-inflammatory gene transcription in glia, leading to various inflammatory reactions. This review compares literature regarding neuroinflammation in AD and ALS, with special emphasis on roles played by tumor necrosis factor alpha (TNFalpha) and aberrant arachidonic acid metabolism in the genesis of chronic oxidative conditions. Based on our observations made in the G93A-SOD1 mouse model of ALS, and a body of Alzheimer's disease findings, we hypothesize a prominent pathological role for the TNFalpha-signaling axis and neuroinflammation in the pathogenesis of both diseases. A discussion is made regarding the relevance of neuroinflammation to potential therapeutic implications for both ALS and AD.
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PMID:Oxidative stress and neuroinflammation in Alzheimer's disease and amyotrophic lateral sclerosis: common links and potential therapeutic targets. 1509 98

Two double-blind, randomized, placebo-controlled feasibility trials of minocycline in ALS were conducted. In Trial 1, 19 subjects received 200 mg/day or placebo for 6 months; there were no significant differences in adverse events (AE). In Trial 2, 23 subjects received up to 400 mg/day in an 8-month crossover trial. The mean tolerated dose was 387 mg/day, there was a trend toward more gastrointestinal AE (p = 0.057), and blood urea nitrogen and liver enzymes became elevated (p < 0.05). Using these data, the authors have designed and launched a phase III trial.
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PMID:Placebo-controlled phase I/II studies of minocycline in amyotrophic lateral sclerosis. 1515 21


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