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)

To evaluate reports of abnormal levels of free amino acids (AA) in patients with amyotrophic lateral sclerosis (ALS), we studied serum, cerebrospinal fluid, and urine AA in 12 patients with ALS and 12 controls matched for age, sex, and severity of disability. ALS patients had statistically significant elevations in serum levels of tyrosine, total aromatic AA, and total basic AA. ALS patients also had statistically significant elevations in cerebrospinal fluid of total basic AA, lysine, essential AA, and leucine. The severity of ALS correlated inversely with acidic AA (glutamate and aspartate) and O-phosphoserine in cerebrospinal fluid. Activity of ALS correlated directly with serum aspartate and cerebrospinal fluid alanine. We conclude that subtle abnormalities of AA levels are present in ALS and that these are not due to age, sex, or disability. The pattern of distribution of AA levels differs from that in hepatic or renal disease and suggests defective membrane transport or poor cellular utilization of basic and essential AA in the central nervous system.
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PMID:Free amino acid levels in amyotrophic lateral sclerosis. 66 70

Data from the literature about plasma and CSF amino acid (AA) levels in amyotrophic lateral sclerosis (ALS) remain controversial. To refine such analyses we used HPLC, and report a study of plasma and CSF AA concentrations in patients with ALS, the type of the disease (spinal and bulbar onset) being precisely determined. In ALS, there is a decrease in the plasma levels of the large neutral amino acids (LNAA) alanine, isoleucine, leucine, methionine and tyrosine which was particularly striking in the bulbar type (p < 0.05). Plasma glutamate levels do not differ between ALS and controls, but are significantly increased in ALS with spinal onset and decreased in the bulbar type (p < 0.05 vs controls, p < 0.001 bulbar vs spinal). In CSF, the analysis of the whole ALS group shows no difference from controls. However, there is an increase of CSF serine, glutamine and alanine in ALS with spinal onset (p < 0.05). Our results do not support an abnormal profile of excitatory AA concentrations in ALS. The heterogeneous changes we observed, mainly concerning LNAAs, may be explained by a blood-CSF barrier disturbance in the disease. As AA levels clearly differ between ALS types, with low concentrations in bulbar ALS, this dual profile probably explains some of the discrepancies between previous studies.
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PMID:Fasting plasma and CSF amino acid levels in amyotrophic lateral sclerosis: a subtype analysis. 808 43

Following the report of an increased mortality among patients with amyotrophic lateral sclerosis given high daily doses of branched-chain aminoacids, we assessed the plasma concentrations of large neutral aminoacids and glutamic acid and the large neutral aminoacid brain influx in 24 amyotrophic lateral sclerosis patients receiving placebo or branched-chain aminoacids (L-leucine 12 g, L-isoleucine 6 g, L-valine 6 g daily), in 15 untreated amyotrophic lateral sclerosis patients and in 15 healthy volunteers. The branched-chain aminoacid plasma concentrations increased three- to six-fold in the treated group compared to the patients receiving placebo or no treatment and to the healthy controls. Plasma glutamic acid concentrations in healthy volunteers were 51.59 +/- 7.53 nmol/ml while in the amyotrophic lateral sclerosis patients receiving no treatment, placebo or branched-chain aminoacids were 92.33 +/- 12.15 nmol/ml, 91.21 +/- 15.86 nmol/ml and 95.08 +/- 17.96 nmol/ml respectively. The glutamic acid concentration was significantly higher (P < 0.01) in amyotrophic lateral sclerosis patients than in healthy individuals. Plasma phenylalanine and tyrosine were lower in the amyotrophic lateral sclerosis patients than in healthy controls, regardless of treatment, whereas tryptophan levels were not significantly different. The branched-chain aminoacid brain influx of the treated group was 110-140% of that measured in the patients receiving placebo and in the healthy controls. The aromatic aminoacid brain influx was lower in the treated group than in the placebo group or healthy controls. An impairment of brain large neutral aminoacid availability might possible contribute to enhancing the progression of symptoms in patients with amyotrophic lateral sclerosis.
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PMID:The imbalance of brain large-chain aminoacid availability in amyotrophic lateral sclerosis patients treated with high doses of branched-chain aminoacids. 857 75

Spinal cords of sporadic cases with amyotrophic lateral sclerosis (ALS) and normal controls were immunohistochemically examined using antibodies for Cu/Zn superoxide dismutase (SOD) and nitrotyrosine (NT). Immunoreactivity for Cu/Zn SOD of the motor neurons was not different between the ALS and controls. In contrast, immunoreactivity for NT was densely detected in motor neurons of ALS but was not or was only minimally detected in those of controls. The staining was also found in the axons of motor neurons of ALS, but was not found in the controls. These results suggest that nitration of protein-tyrosine residue is upregulated in motor neurons of the spinal cord of ALS.
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PMID:Induction of nitrotyrosine-like immunoreactivity in the lower motor neuron of amyotrophic lateral sclerosis. 858 46

Oxidative stress has been proposed as a pathogenetic mechanism in Alzheimer's disease. One mechanism of oxidative damage is the nitration of tyrosine residues in proteins, mediated by peroxynitrite breakdown. Peroxynitrite, a reaction product of nitric oxide and superoxide radicals, has been implicated in N-methyl-D-aspartate receptor-mediated excitotoxic damage. Reported evidence of oxidative stress in Alzheimer's disease includes increased iron, alterations in protective enzymes, and markers of oxidative damage to proteins and lipids. In this report, we demonstrate the presence of nitrotyrosine in neurofibrillary tangles of Alzheimer's disease. Nitrotyrosine was not detected in controls lacking neurofibrillary tangles. Immunolabeling was demonstrated to be specific nitrotyrosine in a series of control experiments. These observations link oxidative stress with a key pathological lesion of Alzheimer's disease, the neurofibrillary tangle, and demonstrate a pathogenetic mechanism in common with the other major neurodegenerative diseases of aging, Parkinson's disease and amyotrophic lateral sclerosis. These findings further implicate nitric oxide expression and excitotoxicity in the pathogenesis of cell death in Alzheimer's disease.
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PMID:Evidence of neuronal oxidative damage in Alzheimer's disease. 868 45

Peroxynitrite, formed from nitric oxide and superoxide, may affect neurofilament assembly and cause neurofilament accumulation in motoneurons. This hypothesis may reconcile the mutations of two genes: superoxide dismutase-1 in some patients with familial amyotrophic lateral sclerosis, and the gene for the heavy neurofilament in some patients with sporadic amyotrophic lateral sclerosis previously reported. We found colocalization of superoxide dismutase-1 and nitric oxide synthase in the foci of neurofilament accumulation as 'conglomerates' in upper motor neurons and 'axonal spheroids' in lower motor neurons. In addition, all the specific molecules related to the reactions, including calmodulin, 3', 5'-cyclic guanosine-monophosphate, citrulline, and nitrotyrosine were found strongly immunopositive in the site of neurofilament accumulation. Our data support the view that the neurofilament aggregates are tightly linked with superoxide dismutase-1 and nitric oxide synthase activities. Both enzymes may focally contribute to peroxynitrite formation at light neurofilament, which is rich in both tyrosine and arginine residues and hence considered as the vulnerable site for nitrotyrosine formation. Nitrotyrosine is known to inhibit phosphorylation and if it impairs phosphorylation of neurofilament subunits, either light or heavy, may alter the slow axonal transport culminating in proximo-distal accumulation of NF and slowly progressive motoneuron death.
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PMID:Colocalization of NOS and SOD1 in neurofilament accumulation within motor neurons of amyotrophic lateral sclerosis: an immunohistochemical study. 881 14

A number of free radicals such as superoxide and nitric oxide may cause damage to motor neurons but the exact mechanism remains to be elucidated. A potent free radical, peroxynitrite, is readily formed from superoxide and nitric oxide, which captures superoxide three times faster than SOD-1. Peroxynitrite may nitrate tyrosine residues of light neurofilaments (NF-I), thereby altering NF assembly and causing NF accumulation in motor neurons. To test this hypothesis we have probed the massive NF aggregates which are histopathological hallmarks of ALS/MND with immunohistochemistry. We investigated localization of reaction products related to SOD-1, nitric oxide synthase (NOS) and cyclic GMP activities. Our studies show colocalization of NF aggregates with SOD-1/b-NOS/calmodulin /citrulline/cGMP and nitrotyrosine in upper motor neuron conglomerates (Cgl) and lower motor neutron axonal spheroids (Axs). This strongly supports the notion that peroxynitrite deranges NF phosphorylation and assembly, by nitrating tyrosine residues in NF-L. Impaired phosphorylation of NF subunits, either at NF-I or at NF-H, may affect the slow axonal transport culminating in proximo-distal accumulation of NF and slowly progressive motoneuron death.
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PMID:Role of SOD-1 and nitric oxide/cyclic GMP cascade on neurofilament aggregation in ALS/MND. 889 53

Nitric oxide contrasts with most intercellular messengers because it diffuses rapidly and isotropically through most tissues with little reaction but cannot be transported through the vasculature due to rapid destruction by oxyhemoglobin. The rapid diffusion of nitric oxide between cells allows it to locally integrate the responses of blood vessels to turbulence, modulate synaptic plasticity in neurons, and control the oscillatory behavior of neuronal networks. Nitric oxide is not necessarily short lived and is intrinsically no more reactive than oxygen. The reactivity of nitric oxide per se has been greatly overestimated in vitro because no drain is provided to remove nitric oxide. Nitric oxide persists in solution for several minutes in micromolar concentrations before it reacts with oxygen to form much stronger oxidants like nitrogen dioxide. Nitric oxide is removed within seconds in vivo by diffusion over 100 microns through tissues to enter red blood cells and react with oxyhemoglobin. The direct toxicity of nitric oxide is modest but is greatly enhanced by reacting with superoxide to form peroxynitrite (ONOO-). Nitric oxide is the only biological molecule produced in high enough concentrations to out-compete superoxide dismutase for superoxide. Peroxynitrite reacts relatively slowly with most biological molecules, making peroxynitrite a selective oxidant. Peroxynitrite modifies tyrosine in proteins to create nitrotyrosines, leaving a footprint detectable in vivo. Nitration of structural proteins, including neurofilaments and actin, can disrupt filament assembly with major pathological consequences. Antibodies to nitrotyrosine have revealed nitration in human atherosclerosis, myocardial ischemia, septic and distressed lung, inflammatory bowel disease, and amyotrophic lateral sclerosis.
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PMID:Nitric oxide, superoxide, and peroxynitrite: the good, the bad, and ugly. 894 24

The first part of this paper summarizes the main pathological features of sporadic amyotrophic lateral sclerosis (ALS) and familial amyotrophic lateral sclerosis (FALS). In both diseases, the primary lesion consists of degeneration of both upper and lower motor neurons, resulting in severe neuronal loss, particularly in the spinal cord. An important difference between sporadic ALS and FALS is in the involvement of sensory and spinocerebellar projections in the latter. The second part of the paper will compare the familial form of ALS with its recently described transgenic murine model. The production of this model followed the discovery that FALS is tightly linked to several different mutations in the enzyme Cu,Zn superoxide dismutase (SOD), a ubiquitous enzyme involved in the dismutation of superoxide anion to hydrogen peroxide. A human transgene with one of the identified mutations was expressed in mice, and the resulting progeny developed clinical and pathological changes that, in the late stages of disease, were very similar to those in patients with FALS. There was, in fact, exquisite degeneration of motor neurons in spinal cord and brain stem, as well as degeneration of white matter tracts of the spinal cord, of the anterior roots and neurogenic atrophy of skeletal muscles, as described in patients with FALS. Beckman and colleagues postulated that mutations in SOD may alter the structure of the copper active site with resultant decrease in superoxide anion dysmutation while favoring an increase in reactivity with other radicals such as peroxynitrite. The formation of nitronium-like intermediate could damage proteins, particularly by nitration of tyrosine residues. Nitration of tyrosine kinases and altered phosphorilation of neurofilaments could be particularly damaging for motor neurons.
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PMID:Comparison of pathological alterations in ALS and a murine transgenic model: pathogenetic implications. 902 Dec 54

Spinal cords of sporadic cases with amyotrophic lateral sclerosis (ALS) and normal controls were immunohistochemically examined using antibodies for nitrotyrosine (NT), Cu/Zn superoxide dismutase (SOD), and nitric oxide synthase (NOS) of brain, endothelial, and inducible forms. Immunoreactivity for NT was densely detected in the motor neurons of ALS while it was not or was only minimally detected in those of controls. The staining was also found in the axons of motor neurons of ALS, but was not found in the controls. In contrast, although immunoreactivity for Cu/Zn SOD of the motor neurons was dense in the motor neurons, it was not different between the ALS and controls. Immunoreactivities for bNOS and eNOS in the motor neurons of ALS were stronger than those of controls, and were also found in degenerated axons in the anterior horn of ALS. However, the immunoreactivity for inducible NOS was only minimally detected in the motor neurons of ALS and controls, and was not detected in the degenerated axons of ALS. These results suggest that nitration of protein-tyrosine residue is upregulated in motor neurons of the spinal cord of ALS with selective increases of brain NOS- and endothelial NOS-like immunoreactivities.
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PMID:Upregulation of protein-tyrosine nitration in the anterior horn cells of amyotrophic lateral sclerosis. 917 39


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