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

Amyotrophic lateral sclerosis is one of the most common neurodegenerative disorders, with an incidence of about 1/100,000. One of the typical features of this progressive, lethal disease, occurring both sporadically and as a familial disorder, is degeneration of cortical and spinal motor neurones. Present evidence indicates that loss of neurones in patients results from a complex interplay among oxidative injury, excitotoxic stimulation, dysfunction of critical proteins and genetic factors. This review focuses on existing evidence that oxidative stress is a major culprit in the pathogenesis of amyotrophic lateral sclerosis. An increase in reactive oxygen species and in products of oxidation has been observed both in post-mortem samples and in experimental models for ALS. This increase may be consequent to altered metabolism of copper and iron ions, that share the property to undergo redox cycling and generate reactive oxygen species. Metal-mediated oxidative stress would lead to several intracellular alterations and contribute to the induction of cell death pathways.
 ...
PMID:Neurodegeneration in amyotrophic lateral sclerosis: the role of oxidative stress and altered homeostasis of metals. 1290 79

Recent investigations of scrapie, Creutzfeldt-Jakob disease (CJD), and chronic wasting disease (CWD) clusters in Iceland, Slovakia and Colorado, respectively, have indicated that the soil in these regions is low in copper and higher in manganese, and it has been well-known that patients of ALS or Parkinson's disease were collectively found in the New Guinea and Papua islands, where the subterranean water (drinking water) contains much Al3+ and Mn2+ ions. Above facts suggest that these neurodegenerative diseases are closely related with the function of a metal ion. We have investigated the chemical functions of the metal ions in detail and established the unique mechanism of the oxygen activation by the transition metal ions such as iron and copper, and pointed out the notable difference in the mechanism among iron, aluminum and manganese ions. Based on these results, it has become apparent that the incorporation of Al(III) or Mn(II) in the cells induces the "iron-overload syndrome", which is mainly due to the difference in an oxygen activation mechanism between the iron ion and Al(III) or the Mn(II) ion. This syndrome highly promotes formation of hydrogen peroxide, and hydrogen peroxide thus produced can be a main factor to cause serious damages to DNA and proteins (oxidative stress), yielding a copper(II)- or manganese(II)-peptide complex and its peroxide adduct, which are the serious agents to induce the structural changes from the normal prion protein (PrP(c)) to abnormal disease-causing isoforms, PrP(Sc), or the formation of PrP 27-30 (abnormal cleavage at site 90 of the prion protein). It seems reasonable to consider that the essential origin for the transmissible spongiform encephalopathies (TSEs) should be the incorporation and accumulation of Al(III) and Mn(II) ions in the cells, and the sudden and explosive increase of scrapie and bovine spongiform encephalopathy (BSE) in the last decade may be partially due to "acid rain", because the acid rain makes Al(III) and Mn(II) ions soluble in the subterranean aquifers.
 ...
PMID:Elucidation of endemic neurodegenerative diseases--a commentary. 1457 44

Accumulating evidence supports the hypothesis that brain iron misregulation and oxidative stress (OS), resulting in reactive oxygen species (ROS) generation from H2O2 and inflammatory processes, trigger a cascade of events leading to apoptotic/necrotic cell death in neurodegenerative disorders, such as Parkinson's (PD), Alzheimer's (AD) and Huntington's diseases, and amyotrophic lateral sclerosis (ALS). Thus, novel therapeutic approaches aimed at neutralization of OS-induced neurotoxicity, support the application of ROS scavengers, transition metals (e.g. iron and copper) chelators and non-vitamin natural antioxidant polyphenols, in monotherapy, or as part of antioxidant cocktail formulation for these diseases. Both experimental and epidemiological evidence demonstrate that flavonoid polyphenols, particularly from green tea and blueberries, improve age-related cognitive decline and are neuroprotective in models of PD, AD and cerebral ischemia/reperfusion injuries. However, recent studies indicate that the radical scavenger property of green tea polyphenols is unlikely to be the sole explanation for their neuroprotective capacity and in fact, a wide spectrum of cellular signaling events may well account for their biological actions. In this article, the currently established mechanisms involved in the beneficial health action and emerging studies concerning the putative novel molecular neuroprotective activity of green tea and its major polyphenol (-)-epigallocatechin-3-gallate (EGCG), will be reviewed and discussed.
 ...
PMID:Cell signaling pathways in the neuroprotective actions of the green tea polyphenol (-)-epigallocatechin-3-gallate: implications for neurodegenerative diseases. 1500 57

Membrane lipid peroxidation and oxidative modification of various membrane and associated proteins (e.g., receptors, ion transporters and channels, and signal transduction and cytoskeletal proteins) occur in a range of neurodegenerative disorders. This membrane-associated oxidative stress (MAOS) is promoted by redox-active metals, most notably iron and copper. The mechanisms whereby different genetic and environmental factors initiate MAOS in specific neurological disorders are being elucidated. In Alzheimer's disease (AD), the amyloid beta-peptide generates reactive oxygen species and induces MAOS, resulting in disruption of cellular calcium homeostasis. In Parkinson's disease (PD), mitochondrial toxins and perturbed ubiquitin-dependent proteolysis may impair ATP production and increase oxyradical production and MAOS. The inheritance of polyglutamine-expanded huntingtin may promote neuronal degeneration in Huntington's disease (HD), in part, by increasing MAOS. Increased MAOS occurs in amyotrophic lateral sclerosis (ALS) as the result of genetic abnormalities (e.g., Cu/Zn-superoxide dismutase mutations) or exposure to environmental toxins. Levels of iron are increased in vulnerable neuronal populations in AD and PD, and dietary and pharmacological manipulations of iron and copper modify the course of the disease in mouse models of AD and PD in ways that suggest a role for these metals in disease pathogenesis. An increasing number of pharmacological and dietary interventions are being identified that can suppress MAOS and neuronal damage and improve functional outcome in animal models of AD, PD, HD, and ALS. Novel preventative and therapeutic approaches for neurodegenerative disorders are emerging from basic research on the molecular and cellular actions of metals and MAOS in neural cells.
 ...
PMID:Metal-catalyzed disruption of membrane protein and lipid signaling in the pathogenesis of neurodegenerative disorders. 1510 54

The presence of oxidative damage and increased iron deposition in CNS tissues of ALS patients prompted the authors to examine the prevalence of two common HFE gene mutations linked to iron accumulation and consequent oxidative stress. The prevalence of the C282Y and H63D mutations was nearly identical in 51 ALS patients and 47 normal control subjects. The presence of either mutation did not significantly affect the age at onset or rate of progression in ALS.
 ...
PMID:HFE mutations are not strongly associated with sporadic ALS. 1513 93

Iron has been shown to accumulates at site where neurons degenerate in neurodegenerative diseases of Parkinson's disease, Alzheimer's disease, Huntington disease, amyotrophic lateral sclerosis and Friedreich ataxia. Iron is thought to participate or initiate oxidative stress via generation of reactive oxygen species (ROS), such as hydroxyl radical. Iron chelators are neuroprotective and prevent 6-hydroxydoapmine and MPTP dopaminergic neurotoxicity in rats and mice. However, their action on monoamine oxidase (MAO) A and B have not been determined previously since MAO-B inhibitors have been shown to be neuroprotective in cellular and animal models of Parkinson's disease. The chelators 8-hydroxyquinoline, O-phenanthroline, 2,2'-dipyridyl, U74500A and U74600F showed a preference for inhibition of rat brain mitochondrial MAO-A over MAO-B. Their IC(50) ranged from 10(-3) M to 10(-6) M, with 21-amino steroids (U74500A and U74006F) showing a greater selectivity and potency for MAO-A. Desferrioxamine (desferal), a prototype potent iron chelator, exhibited relatively poor MAO inhibitory. The inhibitions of MAO-A and B by 21-amino steroids (Lazaroids) were time dependent and irreversible. Those initiated by 8-hydroxyquinoline, 2,2'-dipyridyl and O-phenanthroline were fully reversible by enzyme dilution experiments. Both Fe(2+) and Fe(3+) reverse the MAO-A and B inhibition induced by the latter chelators, but not those initiated by 21-amino steroids. The data infer that either the inhibition of MAO by 21-amino steroids is either the resultant of their conversion to an irreversible covalently bound ligand or that the iron chelation moiety and MAO inhibitory activity in these compounds are not mutually shared. The results suggest that bifunctional brain penetrable drugs with iron chelating property and MAO inhibitory activity in could be the most feasible approach for neuroprotection in neurodegenerative diseases. Such drug would prevent participation of elevated iron in oxidative stress and formation of reactive hydroxyl radical, via its interaction with H(2)O2 (Fenton chemistry), generated as a consequence MAO and other oxidative enzyme reactions to generative cytotoxic reactive hydroxyl radical. We have now developed several of these compounds with neuroprotective, MAO inhibitory and iron chelating properties from our prototype iron chelators, VK-28 possessing propargylamine moiety of our anti-parkinson drug, rasagiline.
 ...
PMID:Novel bifunctional drugs targeting monoamine oxidase inhibition and iron chelation as an approach to neuroprotection in Parkinson's disease and other neurodegenerative diseases. 1548 Aug 46

The etiology of amyotrophic lateral sclerosis (ALS) is unknown. The presence of mutations in the superoxide dismutase gene (SOD1) has led to theories regarding a role for oxidative stress in the pathogenesis of this disease. A primary cause of oxidative stress is perturbations in cellular iron homeostasis. Cellular iron mismanagement and oxidative stress are associated with a number of neurodegenerative diseases. One mechanism by which cells fail to properly regulate their iron status is through a mutation in the Hfe gene. Mutations in the Hfe gene are associated with the iron overload disease, hemochromatosis. In the current study, 31% of patients with sporadic ALS carried a mutation in the Hfe gene, compared to only 14% of patients without identifiable neuromuscular disease, or with neuromuscular diseases other than ALS (p<0.005). To determine the cellular consequences of carrying an Hfe mutation, a human neuronal cell line was transfected with genes carrying the Hfe mutation. The presence of the Hfe mutation disrupted expression of tubulin and actin at the protein levels potentially consistent with the disruption of axonal transport seen in ALS and was also associated with a decrease in CuZnSOD1 expression. These data provide compelling evidence for a role for the Hfe mutation in etiopathogenesis of ALS and warrant further investigation.
 ...
PMID:Increased incidence of the Hfe mutation in amyotrophic lateral sclerosis and related cellular consequences. 1554 88

Degeneration of nigrostriatal dopamine neurons and cholinergic cortical neurones are the main pathological features of Parkinson's disease (PD) and for the cognitive deficit in dementia of the Alzheimer' type (AD) and in dementia with Lewy bodies (DLB), respectively. Many PD and DLB subjects have dementia and depression resulting from possible degeneration of cholinergic and noradrenergic and serotonergic neurons. On the other hand, AD patients may also develop extrapyramidal features as well as depression. In both PD and AD there is, respectively, accumulation of iron within the melanin containing dopamine neurons of pars compacta and with in the plaques and tangle. It has been suggested that iron accumulation may contribute to the oxidative stress induced apoptosis reported in both diseases. This may result from increased glia hydrogen peroxide producing monoamine oxidase (MAO) activity that can generate of reactive hydroxyl radical formed from interaction of iron and hydrogen peroxide. We have therefore prepared a series of novel bifunctional drugs from the neuroprotective-antiapoptotic antiparkinson monoamine oxidase B inhibitor, rasagiline, by introducing a carbamate cholinesterase (ChE) inhibitory moiety into it. Ladostigil (TV-3326, N-propargyl-3R-aminoindan-5yl)-ethyl methylcarbamate), has both ChE and MAO-AB inhibitory activity, as potential treatment of AD and DLB or PD subjects with dementia Being a brain selective MAO-AB inhibitor it has limited potentiation of the pressor response to oral tyramine and exhibits antidepressant activity similar to classical non-selective MAO inhibitor antidepressants by increasing brain serotonin and noradrenaline. Ladostigil inhibits brain acetyl and butyrylcholinesterase in rats and antagonizes scopolamine-induced inhibition of spatial learning. Ladostigil like MAO-B inhibitor it prevents MPTP Parkinsonism in mice model and retains the in vitro and in vivo neuroprotective activity of rasagiline. Ladostigil, rasagiline and other propargylamines have been demonstrated to have neuroprotective activity in several in vitro and in vivo models, which have been shown be associated with propargylamines moiety, since propargylamines itself possess these properties. The mechanism of neuroprotective activity has been attributed to the ability of propargylamines-inducing the antiapoptotic family proteins Bcl-2 and Bcl-xl, while decreasing Bad and Bax and preventing opening of mitochondrial permeability transition pore. Iron accumulates in brain regions associated with neurodegenerative diseases of PD, AD, amyotrophic lateral sclerosis and Huntington disease. It is thought to be involved in Fenton chemistry oxidative stress observed in these diseases. The neuroprotective activity of propargylamines led us to develop several novel bifunctional iron chelator from our prototype brain permeable iron chelators, VK-28, possessing propargylamine moiety (HLA-20, M30 and M30A) to iron out iron from the brain. These compounds have been shown to have iron chelating and monoamine oxidase A and B selective brain inhibitory and neuroprotective-antiapoptotic actions.
 ...
PMID:Bifunctional drug derivatives of MAO-B inhibitor rasagiline and iron chelator VK-28 as a more effective approach to treatment of brain ageing and ageing neurodegenerative diseases. 1562 Dec 13

There is significant evidence that the pathogenesis of several neurodegenerative diseases, including Parkinson's disease, Alzheimer's disease, Friedreich's ataxia (FRDA), multiple sclerosis and amyotrophic lateral sclerosis, may involve the generation of reactive oxygen species (ROS) and/or reactive nitrogen species (RNS) associated with mitochondrial dysfunction. The mitochondrial genome may play an essential role in the pathogenesis of these diseases, and evidence for mitochondria being a site of damage in neurodegenerative disorders is based in part on observed decreases in the respiratory chain complex activities in Parkinson's, Alzheimer's, and Huntington's disease. Such defects in respiratory complex activities, possibly associated with oxidant/antioxidant imbalance, are thought to underlie defects in energy metabolism and induce cellular degeneration. The precise sequence of events in FRDA pathogenesis is uncertain. The impaired intramitochondrial metabolism with increased free iron levels and a defective mitochondrial respiratory chain, associated with increased free radical generation and oxidative damage, may be considered possible mechanisms that compromise cell viability. Recent evidence suggests that frataxin might detoxify ROS via activation of glutathione peroxidase and elevation of thiols, and in addition, that decreased expression of frataxin protein is associated with FRDA. Many approaches have been undertaken to understand FRDA, but the heterogeneity of the etiologic factors makes it difficult to define the clinically most important factor determining the onset and progression of the disease. However, increasing evidence indicates that factors such as oxidative stress and disturbed protein metabolism and their interaction in a vicious cycle are central to FRDA pathogenesis. Brains of FRDA patients undergo many changes, such as disruption of protein synthesis and degradation, classically associated with the heat shock response, which is one form of stress response. Heat shock proteins are proteins serving as molecular chaperones involved in the protection of cells from various forms of stress. In the central nervous system, heat shock protein (HSP) synthesis is induced not only after hyperthermia, but also following alterations in the intracellular redox environment. The major neurodegenerative diseases, Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), multiple sclerosis (MS), Huntington's disease (HD) and FRDA are all associated with the presence of abnormal proteins. Among the various HSPs, HSP32, also known as heme oxygenase I (HO-1), has received considerable attention, as it has been recently demonstrated that HO-1 induction, by generating the vasoactive molecule carbon monoxide and the potent antioxidant bilirubin, could represent a protective system potentially active against brain oxidative injury. Given the broad cytoprotective properties of the heat shock response there is now strong interest in discovering and developing pharmacological agents capable of inducing the heat shock response. This may open up new perspectives in medicine, as molecules inducing this defense mechanism appear to be possible candidates for novel cytoprotective strategies. In particular, manipulation of endogenous cellular defense mechanisms, such as the heat shock response, through nutritional antioxidants, pharmacological compounds or gene transduction, may represent an innovative approach to therapeutic intervention in diseases causing tissue damage, such as neurodegeneration.
 ...
PMID:Oxidative stress, mitochondrial dysfunction and cellular stress response in Friedreich's ataxia. 1589 10

The genetically programmed form of neuronal death known as apoptosis plays a role in many neurodegenerative diseases including Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis (ALS) and Huntington's disease. Apoptosis is also responsible for neuronal death after traumatic brain and spinal cord injury, stroke, and seizures. The cognitive and behavioral consequences of all of these disorders can be devastating. Unfortunately the mechanisms that regulate neuronal apoptosis are complex. However, it is this very complexity that provides us with a wide array of potential targets for the development of anti-apoptotic strategies. Thus, our lab is currently exploring the molecular and cellular mechanisms responsible for neuronal apoptosis, with a particular focus on the role of the metals copper, zinc, and iron. Each of these metals is essential for normal central nervous system (CNS) development and function. However, imbalances, either excess or deficiency, can result in neuronal apoptosis. In this review, we show the relationship between these metals in neurodegenerative disorders and CNS injury, and the mechanisms that govern neuronal survival and apoptosis.
 ...
PMID:Trace metal regulation of neuronal apoptosis: from genes to behavior. 1612 8


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