Decreased Expression of the Slc31a1 Gene and Cytoplasmic Relocalization of Membrane CTR1 Protein in Renal Epithelial Cells: A Potent Protective Mechanism against Copper Nephrotoxicity in a Mouse Model of Menkes Disease.

Kidneys play an especial role in copper redistribution in the organism. The epithelial cells of proximal tubules perform the functions of both copper uptake from the primary urine and release to the blood. These cells are equipped on their apical and basal membrane with copper transporters CTR1 and ATP7A. Mosaic mutant mice displaying a functional dysfunction of ATP7A are an established model of Menkes disease. These mice exhibit systemic copper deficiency despite renal copper overload, enhanced by copper therapy, which is indispensable for their life span extension. The aim of this study was to analyze the expression of Slc31a1 and Slc31a2 genes (encoding CTR1/CTR2 proteins) and the cellular localization of the CTR1 protein in suckling, young and adult mosaic mutants. Our results indicate that in the kidney of both intact and copper-injected 14-day-old mutants showing high renal copper content, CTR1 mRNA level is not up-regulated compared to wild-type mice given a copper injection. The expression of the Slc31a1 gene in 45-day-old mice is even reduced compared with intact wild-type animals. In suckling and young copper-injected mutants, the CTR1 protein is relocalized from the apical membrane to the cytoplasm of epithelial cells of proximal tubules, the process which prevents copper transport from the primary urine and, thus, protects cells against copper toxicity.

In Vivo Modeling of the Pathogenic Effect of Copper Transporter Mutations That Cause Menkes and Wilson Diseases, Motor Neuropathy, and Susceptibility to Alzheimer's Disease.

Copper is an essential biometal, and several inherited diseases are directly associated with a disruption to normal copper homeostasis. The best characterized are the copper deficiency and toxicity disorders Menkes and Wilson diseases caused by mutations in the p-type Cu-ATPase genes ATP7A and ATP7B, respectively. Missense mutations in the C-terminal portion of ATP7A have also been shown to cause distal motor neuropathy, whereas polymorphisms in ATP7B are associated with increased risk of Alzheimer's disease. We have generated a single, in vivo model for studying multiple pathogenic mutations in ATP7 proteins using Drosophila melanogaster, which has a single orthologue of ATP7A and ATP7B. Four pathogenic ATP7A mutations and two ATP7B mutations were introduced into a genomic ATP7 rescue construct containing an in-frame C-terminal GFP tag. Analysis of the wild type ATP7-GFP transgene confirmed that ATP7 is expressed at the basolateral membrane of larval midgut copper cells and that the transgene can rescue a normally early lethal ATP7 deletion allele to adulthood. Analysis of the gATP7-GFP transgenes containing pathogenic mutations showed that the function of ATP7 was affected, to varying degrees, by all six of the mutations investigated in this study. Of particular interest, the ATP7BK832R Alzheimer's disease susceptibility allele was found, for the first time, to be a loss of function allele. This in vivo system allows us to assess the severity of individual ATP7A/B mutations in an invariant genetic background and has the potential to be used to screen for therapeutic compounds able to restore function to faulty copper transport proteins.

[Essential trace element and skin diseases].

We have described herein various skin diseases which are caused by essential trace element deposition, deficiency, allergy, etc. Pigmentation of hemochromatosis and hemosiderosis are recognized by hemosiderin deposition in the dermis. Acrodermatitis enteropathica is caused by a deficiency of Zn and is classified as either a hereditary type or as an acquired type. The former is autosomal recessive and the latter is caused by a low intake of Zn. Wilson's disease and Menkes' kinky hair syndrome, which are caused by abnormal Cu metabolism, elicit hyperpigmentation and morphological changes of the hair, respectively. It appears that kinky hair formation results from low activity of sulfhydryl oxidase which is a Cu enzyme. Bowen disease, which is carcinoma in situ, is caused by As toxicosis. Some cases, such as palmo-plantar-pustulosis, lichen planus and oral lichen planus are caused by allergies to metals used in dental surgery, especially Ni, Co, Cr and Sn.

Enfermedad de Menkes: presentación de un caso y revisión bibliográfica / Menkes´s disease: report of a case and review of the literature

Se presenta un niño de 2 meses de edad que comenzó su enfermedad con convulsiones focales y prolongadas. La primera descripción fue efectuada por Menkes en 1962 en 5 miembros de una familia. Los hallazgos típicos consistían de niños varones con facies características, pelo ensortijado, convulsiones. hiportermia, retardo madurativo y pondoestatural severo que llevan a un estado vegetativo. El curso de esta enfermedad es uniformemente progresivo culminando con la muerte antes de 1 a 3 años de edad. El estudio microscópico de pelo comprueba pili torti, moniletrix y tricorresis nudosa. Estudios radiológicos muestran cambios en los huesos largos consistentes en espolones simétricos metafisarios y reaccion periotal diafisiaria. Estudios angiográficos cerebrales permiten apreciar una anormal tortuosidad de los vasos y variaciones en su calibre. La tomografía computada revela importantes hallazgos patológicos, pricipalmente colecciones subdurales probablemente secuandarias a la atrofia cerebral. El descubrimiento por Danks en 1972 del trastorno en el metabolismo del cobre fue un importante paso en la comprensión de la patología y cuyo defecto básico está en la absorción intestinal. El diagnóstico se efectúa por los niveles bajos de ceruloplasmina y cobre en suero. Esta enfermedad está ligada a la herencia recesiva por el cromosoma X, no existe tratamiento específico pero es posible hoy hacer el diagnóstico prenatal.

Zinc and copper deficiency, with particular reference to parenteral nutrition.

Trace mineral metabolism has reached a new importance and received a new stimulus with the development of total intravenous feeding. A syndrome of acute zinc deficiency has been described in patients receiving intravenous feeding with pure amino acid infusates. Although the rapid response to zinc therapy makes it tempting to assume that the syndrome we have recognized during total parenteral nutrition is one of pure zinc deficiency, it is very likely that this is an oversimplication. The subtle relationships between zinc and other metals, such as calcium, copper, cadmium, and selenium, need further clarification and may account for some patients with low serum zinc not developing the expected clinical manifestations. Copper deficiency also occurs, but its importance is not yet as clearly defined as that of zinc deficiency.