Effect of copper and diethyldithiocarbamate combination therapy on the macular mouse, an animal model of Menkes disease

Abstract

Menkes disease (MD) is a neurodegenerative disorder characterized by a copper deficiency in the brain. It is caused by the defective intestinal absorption of copper resulting from a deficiency of a copper-transporting ATPase, ATP7A. This gives rise to an accumulation of copper in the intestine. The copper deficiency in the brain of MD patients cannot be improved by copper injections, because the administered copper accumulates at the blood-brain barrier and is not transported across to the neurons. To resolve this problem, we investigated the effect of a combination therapy of copper and sodium diethyldithiocarbamate (DEDTC), a lypophilic chelator, in an animal model of MD, the macular mouse. Four-week-old macular mice treated with 50 mug of CuCl2 on the 7th day after birth were used. Experimental mice were given a subcutaneous injection of CuCl2 (4 microg) and an intraperitoneal injection of DEDTC (0.2 mg/g body weight) twice a week for 4 weeks and then sacrificed. Copper concentrations and cytochrome-c oxidase activity in the brains of treated mice were higher than those of control macular mice, which received only copper or saline. The ratios of brain noradrenaline to dopamine and of adrenaline to dopamine were also increased by the treatment, suggesting that the activity of dopamine beta-hydroxylase, a copper-dependent enzyme, was improved by the treatment. Liver and renal function tests showed no abnormalities in the treated mice, although copper concentrations in the kidneys of treated mice were higher than those of control macular mice. These results suggest that DEDTC facilitates the passage of copper across the blood-brain barrier and that the combination therapy of copper and DEDTC may be an effective treatment for the neurological disturbances suffered by patients with MD.

PET Imaging Analysis with 64Cu in Disulfiram Treatment for Aberrant Copper Biodistribution in Menkes Disease Mouse Model

“…Using a small-animal PET imaging system, we obtained the first evidence-to our knowledge-that disulfiram pretreatment efficiently corrects inappropriate copper biodistribution in living MD model mice. The dynamics of administered copper and the time course of the effects of disulfiram in living animals strengthen the results of previous studies demonstrating the effects of disulfiram with conventional methods, such as histochemistry in postmortem animals (20,23). These data accelerate our goal-the clinical application of disulfiram treatment in MD patients.…”

“…With regard to the mechanisms responsible for the effects of disulfiram on copper transport into the brain, the hydrophobicity of DEDTC-an active and converted form of disulfiram-is known to allow the complex of DEDTC and copper to permeate cellular membranes, including the Golgi apparatus (20,23,30). However, the formation of the complex was not demonstrated in vivo in those studies.…”

Copper-related diseases: From chemistry to molecular pathology

“…In the macular mouse, an animal model of Menkes disease characterized by a defective intestinal absorption of copper and by copper deficiency in the brain, the administration of copper by intramuscular injections cannot improve the brain status since administered copper is not transported across the blood-brain barrier. The association of diethyldithiocarbamate to injected copper facilitates the passage of copper ions across the blood-brain barrier, opening a new field of research on copper carriers for the brain with the aim of finding a therapy for children affected by Menkes disease [199]. The human copper transporter hCutC, a member of the Cut family associated with copper homeostasis, was isolated from human foetal brains.…”

Copper-trafficking efficacy of copper-pyruvaldehyde bis(N4-methylthiosemicarbazone) on the macular mouse, an animal model of Menkes disease

“…Subcutaneous injection of copper-histidine ameliorates the natural history of MD when started in early infancy (4,5). However, penetration of copper into the brain remains insufficient due to impaired copper transport after the blood-brain barrier becomes mature, whereas copper abnormally accumulates in the kidneys and the intestine (6). To overcome the insufficient copper distribution to the brain, diethyldithiocarbamate, a lipid-soluble chelator, has been proposed in combination with copper replacement therapy.…”

“…To overcome the insufficient copper distribution to the brain, diethyldithiocarbamate, a lipid-soluble chelator, has been proposed in combination with copper replacement therapy. This compound significantly increases copper levels in the brain, although the copper accumulation in the kidney remains high (6,7).…”