CtpB is a plasma membrane copper (I) transporting P-type ATPase of Mycobacterium tuberculosis

BACKGROUND: The intracellular concentration of heavy-metal cations, such as copper, nickel, and zinc is pivotal for the mycobacterial response to the hostile environment inside macrophages. To date, copper transport mediated by P-type ATPases across the mycobacterial plasma membrane has not been sufficiently explored. RESULTS: In this work, the ATPase activity of the putative Mycobacterium tuberculosis P1B-type ATPase CtpB was associated with copper (I) transport from mycobacterial cells. Although CtpB heterologously expressed in M. smegmatis induced tolerance to toxic concentrations of Cu2+ and a metal preference for Cu+, the disruption of ctpB in M. tuberculosis cells did not promote impaired cell growth or heavy-metal accumulation in whole mutant cells in cultures under high doses of copper. In addition, the Cu+ ATPase activity of CtpB embedded in the plasma mem-brane showed features of high affinity/slow turnover ATPases, with enzymatic parametersKM 0.19 ± 0.04 µM and Vmax 2.29 ± 0.10 nmol/mg min. In contrast, the ctpB gene transcription was activated in cells under culture conditions that mimicked the hostile intraphagosomal environment, such as hypoxia, nitrosative and oxidative stress, but not under high doses of copper. CONCLUSIONS: The overall results suggest that M. tuberculosis CtpB is associated with Cu+ transport from mycobacterial cells possibly playing a role different from copper detoxification.

Enfermedad de Wilson: reporte de caso / Wilson ́s disease: a case report

La enfermedad de Wilson es una condición genética autosómica recesiva poco frecuente. Se ha identificado el gen ATP7B como el que codifica la proteína transportadora de cobre y su deficiencia lleva al acúmulo del metal en el cerebro, hígado y otros órganos vitales. Su diagnóstico clínico precoz es esencial para mejorar la calidad de vida del paciente. A continuación, se presenta el caso de un paciente de 20 años, masculino, con un cuadro clínico de 2 años de evolución de desinhibición, impulsividad, anartria y apraxia de la marcha, movimientos distónicos faciales y en 4 extremidades. Al examen físico se evidenció el anillo de Kayser Flescher a nivel ocular. En Resonancia Magnética Encefálica hiperintensidad en ganglios de la base y mesencéfalo en T2. Ceruloplasmina en suero 4.08 mg/dL. Cobre sérico 26.03ug/dL y cobre en orina de 24 horas 224.30ug/ 24h. Se confirma el diagnóstico de Enfermedad de Wilson, tratándose con D- Penicilamina, evidenciándose una evolución adecuada, con mejoría notable del cuadro neurológico. El tratamiento precoz permite una evolución favorable temprana del paciente, disminuyendo las secuelas neurológicas secundarias a la enfermedad; de ahí la importancia del reporte del presente caso.(AU)

BackgroundWilson's disease is a rare autosomal recessive genetic condition. The ATP7B gene has been identified as the one that encodes the copper transport protein and its deficiency leads to the accumulation of metal in the brain, liver and other vital organs. Your early clinical diagnosis is essential to improve the quality of life of the patient. Following we present the clinical case of a 20-year-old male patient who since 2 years ago, presented disinhibition, impulsivity, anartria and gait apraxia, facial dystonic movements and in extremities. To the physical exam, Kayser Flescher ring was present. In Brain Magnetic Resonance hyperintensity in Basal Ganglia and Midbrain. Serum Ceruloplasmin 4.08. Serum Copper 26.03. Urinary Cupper 224.30. The diagnosis of Wilson's disease is confirmed, treating with D-Penicillamine, evidencing an adequate evolution, with notable improvement of the neurological symptoms. Early treatment allows a favorable early evolution of the patient, reducing the neurological sequelae secondary to the disease; so that the importance of the report of this case.(AU)

Doença de Wilson em crianças e adolescentes: como fazer diagnóstico precoce / Wilson's disease in children and adolescent: a key to an early diagnosis

A doença de Wilson é uma desordem autossômica recessiva do metabolismo do cobre, que leva à impregnação desse metal em diversos tecidos como o fígado, cérebro, córnea e rins. Tem prevalência de 1:40.000 e evolui de forma progressiva e fatal se não tratada. Seu diagnóstico depende de suspeição clínica e exames laboratoriais, podendo ser difícil nos pacientes assintomáticos ou com insuficiência hepática grave. A tríade clássica de apresentação é hepática, neurológica e oftalmológica. Na criança, a forma de apresentação mais comum é a hepática (aguda ou crônica). Os critérios diagnósticos são baseados na presença de ceruloplasmina baixa, cobre em urina de 24 horas e cobre livre elevados e avaliação oftalmológica à procura do anel de Kayser-Fleischer. O tratamento medicamentoso deve ser instituído o quanto antes, de forma a evitaremse as lesões teciduais do excesso de cobre, daí a grande importância do diagnóstico precoce. A droga de escolha é a D-penicilamina, mas é necessário o monitoramento de seus possíveis efeitos colaterais e eventuais pioras do quadro neuropsiquiátrico. Existem outras drogas, como a trientina, tetratiomolibdato e o zinco, que também têm efeito na redução do cobre orgânico. (AU)

Wilson disease is an authossomal recessive disorder of copper metabolism that leads to the impregnation of the metal in different tissues such as the liver, brain, cornea and kidneys. There is a prevalence of 1:40,000 and evolution is progressive and fatal if untreated. The diagnosis depends on clinical suspicion and laboratory tests, and may be difficult in situations such as the asymptomatic patients or with severe liver insufficiency. The classic triad presentation is the hepatic, neurological and ophthalmologic disease. In children, the most common is the hepatic (acute or chronic). The diagnosis criteria are based on the presence of low ceruloplasmine, elevated copper in 24-hour urine and high seric copper and ophthalmologic evaluation in search of Kayser Fleischer ring. The medication treatment must be established as soon as possible so as to prevent tissue lesions due to copper excess, hence the great importance of early diagnosis. The drug choice is the D-penicilamin, with careful monitoring of side effects and attention for occasional worsening of the neuropsychiatric state. There are other drugs as trientine, tetratiomolibdato and zinc that also have an effect on the reduction of organic copper. (AU)