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)

Abnormally high postabsorptive venous plasma glutamate levels have been reported for several diseases that are associated with a loss of body cell mass including cancer, human/simian immunodeficiency virus infection, and amyotrophic lateral sclerosis. Studies on exchange rates in well-nourished cancer patients now show that high venous plasma glutamate levels may serve as a bona fide indicator for a decreased uptake of glutamate by the peripheral muscle tissue in the postabsorptive period and may be indicative for a precachectic state. High glutamate levels are also moderately correlated with a decreased uptake of glucose and ketone bodies. Relatively high venous glutamate levels have also been found in non-insulin-dependent diabetes mellitus and to some extent also in the cubital vein of normal elderly subjects, i.e., in conditions commonly associated with a decreased glucose tolerance and progressive loss of body cell mass.
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PMID:Elevated venous glutamate levels in (pre)catabolic conditions result at least partly from a decreased glutamate transport activity. 886 15

Although human retroviruses seem plausible agents of motor neuron diseases, there are only few reports of patients infected by the human immunodeficiency virus, with documented motor neuron disorder. That retroviral infections may cause motor neuron pathology by various mechanisms in animals and humans is known. Neurological symptoms potentially attributed to damage of lower motor neurons are often described during the course of HIV-1 infection and AIDS, however, it is often difficult to establish whether the disorder is primarily affecting the perikarya of lower motor neurons, or whether it is due to a focal proximal axonopathy, or to a dying-back process. We report a 30-year-old heroin abuser, HIV-1 positive, who presented a rapidly progressive limb weakness, muscle wasting, and bulbar signs, in absence of sensory loss of cerebellar and pyramidal signs. Imaging studies were negative. CSF showed increased protein content, negative cytology, and no oligoclonal bands. Serum protein electrophoresis, urinary heavy metal, and viral researches were negative. CD4 cells were counted 340 mm3 with a CD4-CD8 ratio equal to 0.4. Electrophysiology showed acute and chronic neurogenic changes, confirmed by muscle biopsy. Conduction studies along motor and sensory nerves fell within normal range. Biopsy of sural nerve revealed mild myelinated and unmyelinated fiber loss, occasional degeneration and regeneration, unremarkable inflammation. Despite treatment with AZT, zalcitabine, and steroids, the patient died after 3-month illness. Neuropathology showed normal cortical cell Betz's, and hemispheric white matter. Brain stem motor nuclei (inferior olival, dorsal motor of the vagus, hypoglossal) showed atrophy and intracytoplasmatic lipofuscin accumulation. Vacuolization, central chromatolysis, and neuronophagia were rarely seen. As associated pathology, in the fourth ventricle there were two small subependymal foci of demyelination, with reactive astrocytes and vascular proliferation. A possible crucial role of the HIV-1 infection in the development and progression of our patient's illness is considered in view of the known altered immunity proved in MND and ALS cases.
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PMID:Motor neuron disease and HIV-1 infection in a 30-year-old HIV-positive heroin abuser: a causal relationship? 962 4

Glutamic acid is the principal excitatory neurotransmitter in the mammalian central nervous system. Glutamic acid binds to a variety of excitatory amino acid receptors, which are ligand-gated ion channels. It is activation of these receptors that leads to depolarisation and neuronal excitation. In normal synaptic functioning, activation of excitatory amino acid receptors is transitory. However, if, for any reason, receptor activation becomes excessive or prolonged, the target neurones become damaged and eventually die. This process of neuronal death is called excitotoxicity and appears to involve sustained elevations of intracellular calcium levels. Impairment of neuronal energy metabolism may sensitise neurones to excitotoxic cell death. The principle of excitotoxicity has been well-established experimentally, both in in vitro systems and in vivo, following administration of excitatory amino acids into the nervous system. A role for excitotoxicity in the aetiology or progression of several human neurodegenerative diseases has been proposed, which has stimulated much research recently. This has led to the hope that compounds that interfere with glutamatergic neurotransmission may be of clinical benefit in treating such diseases. However, except in the case of a few very rare conditions, direct evidence for a pathogenic role for excitotoxicity in neurological disease is missing. Much attention has been directed at obtaining evidence for a role for excitotoxicity in the neurological sequelae of stroke, and there now seems to be little doubt that such a process is indeed a determining factor in the extent of the lesions observed. Several clinical trials have evaluated the potential of antiglutamate drugs to improve outcome following acute ischaemic stroke, but to date, the results of these have been disappointing. In amyotrophic lateral sclerosis, neurolathyrism, and human immunodeficiency virus dementia complex, several lines of circumstantial evidence suggest that excitotoxicity may contribute to the pathogenic process. An antiglutamate drug, riluzole, recently has been shown to provide some therapeutic benefit in the treatment of amyotrophic lateral sclerosis. Parkinson's disease and Huntington's disease are examples of neurodegenerative diseases where mitochondrial dysfunction may sensitise specific populations of neurones to excitotoxicity from synaptic glutamic acid. The first clinical trials aimed at providing neuroprotection with antiglutamate drugs are currently in progress for these two diseases.
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PMID:The role of excitotoxicity in neurodegenerative disease: implications for therapy. 1033 61

Molecular mechanisms that alter the incidence and rate of neuromuscular disease progression are, in many cases, only partially understood. Several recent studies have asked whether apolipoprotein E (apoE for the protein, APOE for the gene) influences these aspects of specific neuromuscular disorders, as it does in central nervous system disorders such as Alzheimer disease. Although these studies are open to methodological criticism, several interesting trends have emerged. First, the APOE4 allele seems to be associated with an increased risk for developing certain neuromuscular diseases, including diabetic neuropathy and human immunodeficiency viral neuropathy. Second, this allele appears to be associated with faster progression of some neuromuscular diseases, including diabetic neuropathy and possibly motor neuron disease. Third, the APOE2 allele seems to confer protection against developing certain neuromuscular diseases, including the amyotrophic lateral sclerosis (ALS)/parkinsonism/dementia complex of Guam. Finally, this allele is associated with a better prognosis in neuromuscular diseases such as motor neuron disease. The effect of various APOE alleles on neuromuscular diseases therefore parallels their influence on central nervous system diseases. Arch Neurol. 2000;57:1561-1565
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PMID:Apolipoprotein E and neuromuscular disease: a critical review of the literature. 1107 87

chlamdAs with other organ systems, the vulnerability of the nervous system to infectious agents increases with aging. Several different infectious agents can cause neurodegenerative conditions, with prominent examples being human immunodeficiency virus (HIV-1) dementia and prion disorders. Such infections of the central nervous system (CNS) typically have a relatively long incubation period and a chronic progressive course, and are therefore increasing in frequency as more people live longer. Infectious agents may enter the central nervous system in infected migratory macrophages, by transcytosis across blood-brain barrier cells or by intraneuronal transfer from peripheral nerves. Synapses and lipid rafts are important sites at which infectious agents may enter neurons and/or exert their cytotoxic effects. Recent findings suggest the possibility that infectious agents may increase the risk of common age-related neurodegenerative disorders such as Alzheimer's disease (AD) and Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS) and stroke. While scenarios can be envisioned whereby viruses such as Chlamydia pneumoniae, herpes simplex and influenza promote damage to neurons during aging, there is no conclusive evidence for a major role of these pathogens in neurodegenerative disorders. In the case of stroke, blood vessels may be adversely affected by bacteria or viruses resulting in atherosclerosis.
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PMID:Infectious agents and age-related neurodegenerative disorders. 1516 5

Valproic acid (VPA) has long been used as an antiepileptic drug and recently as a mood stabilizer, and evidence is increasing that VPA exerts neuroprotective effects through changes in a variety of intracellular signalling pathways including upregulation of Bcl-2 protein with an antiapoptotic property and inhibiting glycogen synthase kinase 3-beta, which is considered to promote cell survival. Although the neuroprotective effects of VPA have been demonstrated in a murine model of human immunodeficiency virus-1 encephalitis, there have been no reports on the effect of VPA in chronic progressing neurodegenerative disease models including amyotrophic lateral sclerosis (ALS). ALS is a devastating disease selectively affecting motoneurons, and its disease model mice bear a close resemblance to ALS symptomatically and pathologically. First, we used an organotypic slice culture using mouse spinal cord, and showed that VPA protected spinal motoneurons against death from glutamate toxicity in vitro. Then, we treated ALS model mice with VPA at the dose effective level for epileptic model mice after 45 days of age (pre-onset treatment) or the day of the disease onset (post-onset treatment). We found a significant prolongation of the disease duration in ALS model mice in both methods of treatment. Considering the long usage of VPA for epileptic patients with good tolerance and safety, these data strongly support the clinical application of VPA for ALS treatment.
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PMID:Benefit of valproic acid in suppressing disease progression of ALS model mice. 1557 72

Apoptosis plays an important role in neuronal cell death in both chronic and acute human neurodegenerative diseases, including amyotrophic lateral sclerosis, Huntington's disease, cerebral ischemia, and human immunodeficiency virus (HIV) encephalopathy. We evaluated the ability of the extracellular binding domain of a dimeric tumor necrosis factor receptor (p75TNFR) to prevent neurotoxicity and death of human fetal cerebral neurons that were exposed in vitro to toxic agents known to be implicated in human neurological disorders, including tumor necrosis factor (TNFalpha) and the HIV proteins Tat and gp120. The extracellular domain of p75TNFR is capable of binding and neutralizing both soluble and transmembrane-anchored TNFalpha. We efficiently transduced human neurons using adenoviral vectors expressing p75TNFR (Ad.p75TNFR) or a control gene (lacZ). Treatment of control cultures with the toxic agents TNFalpha, TNFalpha plus actinomycin D, or Tat and gp120, induced neurotoxic alterations and apoptotic death of neurons. By contrast, transduction of neurons with Ad.p75TNFR prevented apoptosis and cell death due to these agents. We conclude that viral vector transfer of the p75TNFR gene efficiently protects human neurons from TNFalpha-, Tat- or gp120-induced apoptosis and cell death. These results suggest that p75TNFR transduction of neurons by viral vectors could be therapeutically useful in the treatment of many human neurodegenerative diseases.
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PMID:Protection of human cerebral neurons from neurodegenerative insults by gene delivery of soluble tumor necrosis factor p75 receptor. 1582 36

Increased central nervous system (CNS) levels of monocyte chemoattractant protein 1 [CC chemokine ligand 2 (CCL2) in the systematic nomenclature] have been reported in chronic neurological diseases such as human immunodeficiency virus type 1-associated dementia, amyotrophic lateral sclerosis, and multiple sclerosis. However, a pathogenic role for CCL2 has not been confirmed, and there is no established model for the effects of chronic CCL2 expression on resident and recruited CNS cells. We report that aged (>6 months) transgenic (tg) mice expressing CCL2 under the control of the human glial fibrillary acidic protein promoter (huGFAP-CCL2hi tg+ mice) manifested encephalopathy with mild perivascular leukocyte infiltration, impaired blood brain barrier function, and increased CD45-immunoreactive microglia, which had morphologic features of activation. huGFAP-CCL2hi tg+ mice lacking CC chemokine receptor 2 (CCR2) were normal, showing that chemokine action via CCR2 was required. Studies of cortical slice preparations using video confocal microscopy showed that microglia in the CNS of huGFAP-CCL2hi tg+ mice were defective in expressing amoeboid morphology. Treatment with mutant CCL2 peptides, a receptor antagonist and an obligate monomer, also suppressed morphological transformation in this assay, indicating a critical role for CCL2 in microglial activation and suggesting that chronic CCL2 exposure desensitized CCR2 on microglia, which in the CNS of huGFAP-CCL2hi tg+ mice, did not up-regulate cell-surface expression of major histocompatibility complex class II, CD11b, CD11c, or CD40, in contrast to recruited perivascular macrophages that expressed enhanced levels of these markers. These results indicate that huGFAP-CCL2hi tg+ mice provide a useful model to study how chronic CNS expression of CCL2 alters microglial function and CNS physiology.
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PMID:Chronic expression of monocyte chemoattractant protein-1 in the central nervous system causes delayed encephalopathy and impaired microglial function in mice. 1585 90

Although amyotrophic lateral sclerosis and progressive spinal muscular atrophy have been recognized to occur in association with human immunodeficiency virus infection, to our knowledge, brachial amyotrophic diplegia, a form of segmental motor neuron disease, has not been previously reported. Brachial amyotrophic diplegia results in severe lower motor neuron weakness and atrophy of the upper extremities in the absence of bulbar or lower extremity involvement, pyramidal features, bowel and bladder incontinence, and sensory loss. We describe a human immunodeficiency virus-seropositive man without severe immunosuppression or prior AIDS-defining illnesses who had brachial amyotrophic diplegia. This disorder may represent one end of a spectrum of motor neuron diseases occurring with this retrovirus infection.
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PMID:Brachial amyotrophic diplegia in a patient with human immunodeficiency virus infection: widening the spectrum of motor neuron diseases occurring with the human immunodeficiency virus. 1588 71

The most frequent genetic causes of amyotrophic lateral sclerosis (ALS) determined so far are mutations occurring in the gene coding for copper/zinc superoxide dismutase (Cu,Zn-SOD). The mechanism may involve the formation of hydroxyl radicals or malfunctioning of the SOD protein. Wild-type SOD1 was constructed into a transcription-translation expression vector to examine the SOD1 production in vitro. Wild-type SOD1 was highly expressed in Escherichia coli. Active SOD1 was expressed in a metal-dependent manner. To investigate the possible roles of genetic causes of ALS, a human Cu,Zn-SOD gene was fused with a gene fragment encoding the nine amino acid transactivator of transcription (Tat) protein transduction domain (RKKRRQRRR) of human immunodeficiency virus type 1 in a bacterial expression vector to produce a genetic in-frame Tat-SOD1 fusion protein. The expressed and purified Tat-SOD1 fusion proteins in E. coli can enter PC12 neural cells to observe the cellular consequences. Denatured Tat-SOD1 was successfully transduced into PC12 cells and retained its activity via protein refolding. Three point mutations, E21K, D90V, and D101G, were cloned by site-directed mutagenesis and showed lower SOD1 activity. In undifferentiated PC12 cells, wild-type Tat-SOD1 could prevent DNA fragmentation due to superoxide anion attacks generated by 35 mM paraquat, whereas mutant Tat-D101G enhanced cell death. Our results demonstrate that exogenous human Cu,Zn-SOD fused with Tat protein can be directly transduced into cells, and the delivered enzymatically active Tat-SOD exhibits a cellular protective function against oxidative stress.
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PMID:Identification of three mutations in the Cu,Zn-superoxide dismutase (Cu,Zn-SOD) gene with familial amyotrophic lateral sclerosis: transduction of human Cu,Zn-SOD into PC12 cells by HIV-1 TAT protein basic domain. 1596 76


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