Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:1.4.3.13 (lysyl oxidase)
 1,248 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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. We report a case of OHS in a 34-year-old male, which we believe to be the first Japanese case. He had been noted to have psychomotor retardation since his early childhood and now presents severe psychomotor retardation and muscle atrophy. He shows characteristic facial appearance, hyperelasticity of the skin, joint subluxation and generalized muscular atrophy. Laboratory investigations revealed a low serum copper and ceruloplasmin level as well as intestinal non-absorption of copper. Radiologic imagings showed occipital exostoses and bladder diverticula. The activity of lysyl oxidase, a copper-dependent enzyme involved in cross-link formation in collagen, was decreased in a skin-biopsied specimen. Electronmicroscopic investigation of a muscle biopsy showed irregularity of the myofibrillar network and accumulation of the concentric laminated bodies in the subsarcolemmal regions.
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PMID:[Occipital horn syndrome (Ehlers-Danlos syndrome type IX) with severe psychomotor retardation and muscle atrophy--a first Japanese case]. 168 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

Menkes disease and occipital horn syndrome (OHS) are allelic, X-linked recessive copper-deficiency disorders resulting from mutations in ATP7A, or MNK. Classic Menkes disease has a severe phenotype, with death in early childhood, whereas OHS has a milder phenotype, with, mainly, connective-tissue abnormalities. Data suggest that steady-state localization of ATP7A to the trans-Golgi network (TGN) is necessary for proper activity of lysyl oxidase, which is the predominant cuproenzyme whose activity is deficient in OHS and which is essential for maintenance of connective-tissue integrity. Recently, it was reported that ATP7A-transcript levels as low as 2%-5% of normal are sufficient to result in the milder phenotype, OHS, rather than the phenotype of Menkes disease. In contrast to previously reported cases of OHS, we describe a case of OHS in which, because of a frameshift mutation, no normal ATP7A is produced. Although abundant levels of mutant transcript are present, there are substantially reduced levels of the truncated protein, which lacks the key dileucine motif L1487L1488. It has been demonstrated that the dileucine motif L1487L1488 functions as an endocytic signal for ATP7A cycling between the TGN and the plasma membrane. The present report is the first to describe an ATP7A truncation that results in OHS rather than in Menkes disease. The data from the present report support the concepts that (1) OHS results from lower levels of functional ATP7A and (2) ATP7A does not require the dileucine motif to function in copper efflux.
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PMID:A novel frameshift mutation in exon 23 of ATP7A (MNK) results in occipital horn syndrome and not in Menkes disease. 1143 6

Skin aging has long been important to human beings and in recent years this field has received tremendous attention by both researchers and the general population. Cutaneous aging includes two distinct phenomena, intrinsic aging and photoaging, and is characterized mainly by the loss of collagen fibers from dermis. Proton pump inhibitors (PPIs) are widely prescribed gastric acid-reducing agents that are usually consumed for long periods in some conditions such as gastroesophageal reflux disease. We suggest that PPIs can accentuate skin aging by two mechanisms. First, through increasing intralysosomal PH, PPIs can suppress transforming growth factor-beta (TGFbeta) processing and consequently decrease its secretion. Second, through inhibiting MNK, a P-type ATPase with steady-state localization at the trans-Golgi network, PPIs can hamper copper transport and consequently curb lysyl oxidase activity.
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PMID:Can proton pump inhibitors accentuate skin aging? 2047 Sep 45