Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: 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)

Ultrastructural studies of the skin and aorta of a patient with Menkes disease, an X-linked recessive disorder of copper metabolism, are described. Dermal thickness was normal, while dermal collagen fibrils exhibited a heterogeneous size range, with a mean diameter smaller than normal. Long-spacing collagen was often observed near fibroblasts, the plasma membranes of which were decorated by aggregates of interwoven filaments. Dermal elastin fibers were scarce and consisted of thin strands of amorphous elastin associated with numerous microfibrils. In the aorta, the amount of collagen was normal, although the fibrils displayed a broader range of diameters than normal, with a slightly smaller mean. Elastin fibers showed considerable disruption, appearing fragmented and wider than normal, and displaying irregular contours. The inclusion of cationic dyes during tissue fixation gave rise to numerous electron-dense precipitates within the elastin fibers, suggesting the presence there of glycosaminoglycans or proteoglycans, among which unsulfated and sulfated chondroitins were demonstrated by immunoelectron microscopy to be prominent. Heparan sulfate, observed to be a constituent of normal elastin fibers, was much reduced in amount. Elastin was also found associated with glycosaminoglycans in the soluble matrix of the aortic wall.
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PMID:Ultrastructural analysis of skin and aorta from a patient with Menkes disease. 799 78

Arterial involvement is an important feature of the diagnosis and, above all, prognosis of heritable disorders of connective tissue. In pseudoxanthoma elasticum, a progressive occlusive syndrome is associated with hemorrhage and especially with gastrointestinal bleeding. Aneurysms are uncommon. Hypertension occurs frequently. Cutaneous signs (yellowish pseudo xanthomatous papules of the large folds) the ocular changes (angioid streaks) and pathology showing numerous, thickened, fragmented, disorganized, calcified elastic fibers in the deep dermis and arterial walls, allow the diagnosis to be made. In the heterogeneous group of Ehlers-Danlos syndromes, type IV is characterized by sudden spontaneous rupture of the large arteries. Aneurysms and carotido-cavernous fistulae are rather frequent. Owing to friability of the arterial walls, arteriograms and other procedure requiring arterial puncture may prove hazardous and surgery difficult. Such patients have an acrogeric morphotype, and thin, fragile skin, but cutaneous hyperelasticity and joint hyperlaxity are usually minimal. Pathology evidences collagen hypoplasia in the skin and arterial walls. The severity of Marfan syndrome is due to aortic involvement. A fusiform aneurysm of the ascending aorta represents a vital risk of rupture. Aortic root dilatation is associated and responsible of severe aortic regurgitation. Aortic dissection is also a serious threat. Improved surgical techniques for repairing a dilated or dissected aortic root with simultaneous replacement of the aortic valve increases the life expectancy of such patients. Dolichomorphism is the characteristic skeletal abnormality, particularly with arachnodactyly and upward ectopia lentis, which is almost bilateral, is a very frequent feature of Marfan syndrome. The most typical histological finding is aortic cystic median necrosis. The basic defect in Marfan syndrome concerns the fibrillin, whose gene is located on chromosome 15. The three diseases detailed in this paper constitute the main areas of this subject, but arterial involvement may occur in other inheritable disorders of connective tissue (osteogenesis imperfecta, cutis laxa, Werner syndrome, Menkes syndrome, etc).
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PMID:[Arterial involvements in hereditary dysplasia of the connective tissue]. 805 35

Menkes syndrome in humans is an X-linked disorder characterized in part by abnormal copper transport, cellular copper sequestration, and defective crosslinking of collagen and elastin. A decrease in the functional activity of lysyl oxidase, a cuproenzyme, is thought in part to be responsible for the decreased crosslinking of collagen and elastin. It has also been suggested that low levels of lysyl oxidase activity may occur secondarily to disturbances in intracellular copper translocation and consequently impaired incorporation of copper into lysyl oxidase. Herein, we examine the expression and accumulation of selected extracellular matrix proteins in fibroblasts from a Menkes patient, as well as fibroblasts from the tortoiseshell (MoTo/y) mouse. The MoTo mutation is an allele of the mottled (Mo) locus, which is considered to be a murine analog of the human Menkes locus. In both Menkes and tortoiseshell fibroblasts, levels of lysyl oxidase mRNA transcripts were less than 15% of levels for corresponding controls. The level of elastin mRNA transcripts was also markedly lower in both cell lines in comparison to controls. In contrast, the levels of procollagen Type I mRNA were similar or enhanced in Menkes and MoTo/y fibroblasts compared to their respective controls. Consequently, we conclude that the connective tissue defects associated with Menkes syndrome and those occurring in mottled mouse mutants involve more than abnormal copper utilization in the formation of lysyl oxidase holoenzyme. Based on the present studies in cell culture, the production of essential enzymes and matrix proteins, such as lysyl oxidase and elastin, appear to be altered at the level of transcription or mRNA turnover.
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PMID:Expression and accumulation of lysyl oxidase, elastin, and type I procollagen in human Menkes and mottled mouse fibroblasts. 809 78

Occipital horn syndrome (OHS, Ehlers-Danlos syndrome type IX) belongs to the category of the copper metabolism disorders and is at present being investigated biochemically as is Menkes' disease. Unlike Menkes' disease, most patients with OHS have mild submentality. We report a case of OHS with severe central nervous system involvement and muscular atrophy in a 34-year-old male. He had psychomotor retardation and seizures since early childhood and now presented severe mental retardation and generalized muscular atrophy in addition to characteristic facial appearance, hyperelasticity of the skin and joint subluxation. Laboratory investigations revealed a low serum copper and ceruloplasmin level as well as intestinal non-absorption of copper. Radiographic imaging showed occipital exostoses, bladder diverticula, tortuosity of the peripheral vein and osteoporosis of the skeletal bones. The activity of lysyl oxidase, a copper-enzyme involved in cross-link formation in collagen, was found to be decreased in a skin-biopsy specimen. Electron-microscopic investigation of a muscle biopsy showed irregularity of the myofibrillar network and accumulation of concentric laminated bodies in the subsarcolemmal regions.
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PMID:Central nervous system involvement and generalized muscular atrophy in occipital horn syndrome: Ehlers-Danlos type IX. A first Japanese case. 809 5

The Ehlers-Danlos syndromes (EDS) are a group of heritable connective tissue disorders that share the common features of skin hyperextensibility, articular hypermobility, and tissue fragility. Considerable clinical and genetic heterogeneity exists, and more than nine separate forms have been recognized. Recent advances in the molecular analysis of EDS have identify defects responsible for EDS VI (homozygous and compound heterozygous mutations in the lysyl-hydroxylase gene), EDS VIIA and EDS VIIB (mutations in the type I collagene genes), EDS VIIC (deficiency of procollagen N-proteinase), EDS IX (mutations in the MNK gene), and EDS IV (mutations in the type III collagen gene). Of the various types of Ehlers-Danlos syndrome the most severe is type IV (EDS IV). Early studies showed that fibroblasts from EDS IV patients secreted lower than normal amounts of type III procollagen (Pope et al., 1975). Later, the disease was linked to COL3A1, the gene encoding this protein. More recently, with the publication of full length cDNA and partial characterisation of the gene structure, detailed analysis of mutations in EDS IV patients has become possible. Nineteen different mutations in the type III procollagen gene have been reported in different families with EDS IV. Recent results support the hypothesis that in EDS IV, dominant inheritance should be assumed, in sporadic cases also, unless proven otherwise. Very little is known about the genetics or biochemicals defects responsible for the others EDS subtypes, but with the applications of the tools of molecular biology, analysis of these defects if now within reach.
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PMID:[Ehlers-Danlos syndromes. Clinical, genetic and molecular aspects]. 852 13

Menkes disease is a severe multisystem disorder due to defective bioavailability and transport of copper at the cellular level. Deficient activity of lysyl oxidase, a copper-dependent enzyme, causes defective collagen cross-linking leading to osteoporosis and pathological fractures in these children. The objective of the study was to evaluate the changes in bone mineral density following pamidronate treatment in children with Menkes disease. The study design was an open observational study of three children with Menkes disease and significant osteoporosis with or without pathological fractures, all of whom received pamidronate treatment for 1 year. There were 34-55% and 16-36% increases in lumbar spine bone mineral content and areal bone mineral density, respectively, following 1 year of treatment with pamidronate. There were no further fractures in two of the three children treated. No adverse effects of pamidronate treatment were noted. Pamidronate treatment was associated with an increase in bone mineral density and may be an effective treatment modality for the management of osteoporosis in children with Menkes disease.
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PMID:Pamidronate treatment improves bone mineral density in children with Menkes disease. 1240 89

Metabolites of collagen metabolism were analyzed in patients with Menkes' disease. The urinary deoxypyridinoline level was significantly low in the patients with Menkes' disease, indicating that it is a good marker of lysyl oxidase activity, which is related to the connective tissue abnormalities.
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PMID:Biochemical indicator for evaluation of connective tissue abnormalities in Menkes' disease. 1283 5

To probe mechanisms of cadmium (Cd) damage to the lung extracellular matrix (ECM), we developed Cd-resistant (CdR) rat lung fibroblasts (RFL6) by incubation with graded concentrations of Cd. CdR cells downregulated lysyl oxidase (LO), a copper (Cu)-dependent enzyme essential for crosslinking of collagen and elastin in the ECM, in conjunction with upregulation of other Cu-binding proteins including Cu,Zn-superoxide dismutase (SOD1), copper chaperone for SOD1 (CCS1), metallothionein (MT), and Menkes P-type ATPase (ATP7A), a Cu transporter in the membrane of the Golgi apparatus, as well as gamma-glutamylcysteine synthetase (gamma-GCS), an enzyme for glutathione biosynthesis. Reduction and loss of cytoplasmic distribution of LO in CdR cells were accompanied by its dislocation with the Menkes P-type ATPase and the endoplasmic reticulum marker. CdR cells displayed a defect in LO catalytic activity but an enhancement in Cu,Zn-SOD catalytic activity consistent with the protein expression levels of these enzymes. Although long-term Cd exposure of cells enhanced the Menkes P-type ATPase protein expression, actually, it reduced Cu-dependent catalytic activity of this enzyme in parallel with the deficiency of LO. The low level of 64Cu bound to the LO fraction and the high level of 64Cu bound to the MT fraction provide direct evidence for limitation of Cu bioavailability for LO existing in the CdR cells. These results suggest that downregulation of LO is linked with upregulation of other Cu-binding proteins and with alteration in Cu homeostasis in the CdR phenotype.
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PMID:Perturbation of copper (Cu) homeostasis and expression of Cu-binding proteins in cadmium-resistant lung fibroblasts. 1758 60

Copper is an essential trace element and several copper containing proteins are indispensable for such processes as oxidative respiration, neural development and collagen remodeling. Copper metabolism is precisely regulated by several transporters and chaperone proteins. Copper Transport Protein 1 (CTR1) selectively uptakes copper into cells. Subsequently three chaperone proteins, HAH1 (human atx1 homologue 1), Cox17p and CCS (copper chaperone for superoxide dismutase) transport copper to the Golgi apparatus, mitochondria and copper/zinc superoxide dismutase respectively. Defects in the copper transporters ATP7A and ATP7B are responsible for Menkes disease and Wilson's disease respectively. These proteins transport copper via HAH1 to the Golgi apparatus to deliver copper to cuproenzymes. They also prevent cellular damage from an excess accumulation of copper by mediating the efflux of copper from the cell. There is increasing evidence that copper transport mechanisms may play a role in drug resistance. We, and others, found that ATP7A and ATP7B are involved in drug resistance against the anti-tumor drug cis-diamminedichloroplatinum (II) (CDDP). A relationship between the expression of ATP7A or ATP7B in tumors and CDDP resistance is supported by clinical studies. In addition, the copper uptake transporter CTR1 has also been reported to play a role in CDDP sensitivity. Furthermore, we have recently found that the effect of ATP7A on drug resistance is not limited to CDDP. Using an ex vivo drug sensitivity assay, the histoculture drug response assay (HDRA), the expression of ATP7A in human surgically resected colon cancer cells correlated with sensitivity to 7-ethyl-10-hydroxy-camptothecin (SN-38). ATP7A-overexpressing cells are resistant to many anticancer drugs including SN-38, 7-ethyl-10-[4-(1-piperidino)-1-piperidino] carbonyloxycamptothecin (CPT-11), vincristine, paclitaxel, etoposide, doxorubicin (Dox), and mitoxantron. The mechanism by which ATP7A and copper metabolism modulate drug transport appears to involve modulation of drug cellular localization via modulation of the vesicle transport system. In ATP7A overexpressing cells, Dox accumulates in the Golgi apparatus. In contrast, in the parental cells, Dox is localized in the nuclei, where the target molecules of Dox, topoisomerase II and DNA, are found. Disruption of the intracellular vesicle transport system with monensin, a Na+/H+ ionophore, induced the relocalization of Dox from the Golgi apparatus to the nuclei in the ATP7A overexpressing cells. These data suggested that ATP7A-related drug transport is dependent on the vesicle transport system. Thus copper transport systems play important roles in drug transport as well as in copper metabolism. Components of copper metabolism are therefore likely to include target molecules for the modulation of drug potency of not only anti-cancer agents but also of other drugs.
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PMID:Copper transport systems are involved in multidrug resistance and drug transport. 1907 68

In Menkes disease, arterial tortuosity is frequent, whereas true aneurysms are rare. Here, we report aneurysmal pathology occurring in an infant with Menkes disease. An iliac aneurysm was diagnosed in a 2-month-old boy and attributed to Menkes syndrome on the basis of plasma copper deficiency. Samples of the aneurysmal wall were taken during surgery for histopathological analysis. As in other forms of aneurysm, the arterial wall was characterized by smooth muscle cell (SMC) disappearance, linked to SMC apoptosis and oxidative stress, areas of mucoid degeneration, and extracellular matrix breakdown, including disappearance of elastic fibers and presence of abnormal collagen.
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PMID:Histopathology of an iliac aneurysm in a case of Menkes disease. 1952 51


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