Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022716 (Menkes)
 1,057 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This paper reports the results of a multielement analysis of postmortem samples of Menkes patients, of which one was untreated and two had been treated for various lengths of time with intramuscular injections of copper-EDTA. The findings have been compared with data from a Menkes fetus and from controls. The results confirm that copper accumulates in various tissues and demonstrate a further increase in copper levels as a result of the treatment with copper-EDTA. Although no clinical improvement was observed, the levels of some copper-containing enzymes normalized during the copper-therapy. Furthermore, in agreement with the identification of the copper-binding protein in the kidney as metallothionein, it was found that not only copper, but also zinc, cadmium, and mercury are trapped in this tissue. A low copper concentration in the brain was also found in a Menkes fetus, indicating that brain damage might already have occurred before birth. Speculation Until recently, Menkes' disease was considered to be due to copper deficiency. However, the symptoms are more typical of a storage disease in which copper is irreversibly trapped in some tissues, in particular in the kidneys, by metallothionein. This abnormal storage pattern gives rise to copper deficiency elsewhere in the organism, particularly in the brain where it may cause irreversible damage in the foetus. Parenteral administration of copper does not lead to clinical improvement. The only "therapy" that seems feasible at present is tracing the carriers of the disease and advising abortion when prenatal diagnosis indicates a male fetus carrying the disease.
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PMID:Trace element studies in three patients and a fetus with Menkes' disease. Effect of copper therapy. 678 98

Bacterial plasmids encode resistance systems for toxic metal ions including Ag+, AsO2-, AsO4(3-), Cd2+, CO2+, CrO4(2-), Cu2+, Hg2+, Ni2+, Pb2+, Sb3+, TeO3(2-), Tl+, and Zn2+. In addition to understanding of the molecular genetics and environmental roles of these resistances, studies during the last few years have provided surprises and new biochemical mechanisms. Chromosomal determinants of toxic metal resistances are known, and the distinction between plasmid resistances and those from chromosomal genes has blurred, because for some metals (notably mercury and arsenic), the plasmid and chromosomal determinants are basically the same. Other systems, such as copper transport ATPases and metallothionein cation-binding proteins, are only known from chromosomal genes. The largest group of metal resistance systems function by energy-dependent efflux of toxic ions. Some of the efflux systems are ATPases and others are chemiosmotic cation/proton antiporters. The CadA cadmium resistance ATPase of gram-positive bacteria and the CopB copper efflux system of Enterococcus hirae are homologous to P-type ATPases of animals and plants. The CadA ATPase protein has been labeled with 32P from gamma-32P-ATP and drives ATP-dependent Cd2+ uptake by inside-out membrane vesicles. Recently isolated genes defective in the human hereditary diseases of copper metabolism, Menkes syndrome and Wilson's disease, encode P-type ATPases that are more similar to the bacterial CadA and CopB ATPases than to eukaryote ATPases that pump different cations. The arsenic resistance efflux system transports arsenite, using alternatively either a two-component (ArsA and ArsB) ATPase or a single polypeptide (ArsB) functioning as a chemiosmotic transporter. The third gene in the arsenic resistance system, arsC, encodes an enzyme that converts intracellular arsenate [As (V)] to arsenite [As (III)], the substrate of the efflux system. The three-component Czc (Cd2+, Zn2+, and CO2+) chemiosmotic efflux pump of soil microbes consists of inner membrane (CzcA), outer membrane (CzcC), and membrane-spanning (CzcB) proteins that together transport cations from the cytoplasm across the periplasmic space to the outside of the cell. Finally, the first bacterial metallothionein (which by definition is a small protein that binds metal cations by means of numerous cysteine thiolates) has been characterized in cyanobacteria.
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PMID:Bacterial heavy metal resistance: new surprises. 890 98

In the bakers yeast S. cerevisiae, there at least four intracellular targets requiring copper ions-1) Ccc2p and Fet3p in the secretory pathway (homologues to Menkes/Wilson proteins and ceruloplasmin); 2) cytochrome oxidase in the mitochondria; 3) copper transcription factors in the nucleus; and 4) Cu/Zn superoxide dismutase (SOD1) in the cytosol. We have discovered a small soluble copper carrier that specifically delivers copper ions to the secretory pathway. This 8.2 kDa factor known as Atx1p, exhibits striking homology to the MERp mercury carrier of bacteria and contains a single MTCXXC metal binding site also found in the Menkes/Wilson family of copper transporting ATPases. Our studies show that Atx1p is cytosolic and facilitates the delivery of copper ions from the cell surface copper transporter to Ccc2p and Fet3p in the secretory pathway; furthermore, it is not involved in the delivery of copper ions to the mitochondria, the nucleus or cytosolic SOD1, implicating specific signals directing Atx1p to the secretory pathway. Homologues to Atx1p have been found in invertebrates, plants and humans, and the human gene is abundantly expressed in all tissues. In addition to Atx1p, we have recently uncovered an additional metal trafficking protein that appears to specifically deliver copper ions to SOD1. Mutants in the corresponding gene (lys7) are defective for SOD1 activity, and are unable to incorporate copper into SOD1, while there is no obvious impairment in copper delivery to cytochrome oxidase of Fet3p. The encoded 27 kDa protein contains a single MHCXXC consensus copper binding sequence and close homologues have been identified in a wide array of eukaryotic species including humans.
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PMID:Intracellular pathways of copper trafficking in yeast and humans. 1007 32

A 19-year-old female patient, who had exhibited esotropia, mild cerebellar ataxia, mild mental retardation, and cerebellar atrophy on magnetic resonance images at the age of 15, developed signs of acute encephalopathy, and thereafter died of disseminated intravascular coagulation on the day of her admission. Both her mother and sister suffered from attacks of hemiplegic migraine, mild mental retardation, and cerebellar ataxia. Neuropathological examinations revealed acute changes in the widespread cerebral cortex, chronic degenerative changes in the anterior lobe of the cerebellar vermis, axonal spheroids in the Goll's nucleus, pseudo-calcinosis in the globus pallidus, and glial bundles in the cranial nerves. The most fascinating features were changes of Purkinje cells, such as cactuses (asteroid bodies, dendritic expansions), somatic sprouts, and torpedoes. These changes may be characteristic of familial hemiplegic migraine with cerebellar atrophy, as well as the other metabolic diseases, such as Menkes' kinky hair disease, infantile (Tay-Sachs type) amaurotic idiocy, organic mercury intoxication, and mitochondrial encephalopathy, of which cases often exhibit such pathological changes of Purkinje cells. Therefore, familial hemiplegic migraine may share some metabolic abnormalities with the diseases mentioned above.
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PMID:Autopsy case of acute encephalopathy linked to familial hemiplegic migraine with cerebellar atrophy and mental retardation. 1619 40

The etiology of many neurodegenerative diseases has been only partly attributed to acquired traits, suggesting environmental factors may also contribute. Metal dyshomeostasis causes or has been implicated in many neurodegenerative diseases. Metal flux across the blood-brain barrier (the primary route of brain metal uptake) and the choroid plexuses as well as sensory nerve metal uptake from the nasal cavity are reviewed. Transporters that have been described at the blood-brain barrier are listed to illustrate the extensive possibilities for moving substances into and out of the brain. The controversial role of aluminum in Alzheimer's disease, evidence suggesting brain aluminum uptake by transferrin-receptor mediated endocytosis and of aluminum citrate by system Xc;{-} and an organic anion transporter, and results suggesting transporter-mediated aluminum brain efflux are reviewed. The ability of manganese to produce a parkinsonism-like syndrome, evidence suggesting manganese uptake by transferrin- and non-transferrin-dependent mechanisms which may include store-operated calcium channels, and the lack of transporter-mediated manganese brain efflux, are discussed. The evidence for transferrin-dependent and independent mechanisms of brain iron uptake is presented. The copper transporters, ATP7A and ATP7B, and their roles in Menkes and Wilson's diseases, are summarized. Brain zinc uptake is facilitated by L- and D-histidine, but a transporter, if involved, has not been identified. Brain lead uptake may involve a non-energy-dependent process, store-operated calcium channels, and/or an ATP-dependent calcium pump. Methyl mercury can form a complex with L-cysteine that mimics methionine, enabling its transport by the L system. The putative roles of zinc transporters, ZnT and Zip, in regulating brain zinc are discussed. Although brain uptake mechanisms for some metals have been identified, metal efflux from the brain has received little attention, preventing integration of all processes that contribute to brain metal concentrations.
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PMID:Blood-brain barrier flux of aluminum, manganese, iron and other metals suspected to contribute to metal-induced neurodegeneration. 1711 90

Heavy metals and trace elements play an important role in relation to the physiology and pathology of the nervous system. Neurologic diseases related to disorders of metabolism of copper and iron are reviewed. Copper disorders are divided into two classes: ATP7A- or ATP7B-related inherited copper transport disorders (Menkes disease, occipital horn syndrome, ATP7A-related distal motor neuropathy, and Wilson disease) and acquired diseases associated with copper deficiency or copper excess. Iron brain disorders are divided into genetic neurodegeneration with brain iron accumulation (NBIA, neuroferritinopathy, and aceruloplasminemia), genetic systemic iron accumulation with neurologic features (hemochromatosis), and acquired diseases associated with iron excess (superficial siderosis) or iron deficiency (restless leg syndrome). The main features of cadmium, lead, aluminum, mercury, and manganese toxicity are summarized.
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PMID:Disorders of heavy metals. 2436 57