Copper Accumulation In Liver Research Articles

Hepatic copper accumulates in ferrets with and without hepatobiliary disease.

To determine hepatic copper concentrations and zonal distribution in ferrets with and without hepatobiliary disease, validate rhodanine-based qualitative copper scoring and digital copper quantification in ferret hepatic samples, and ascertain whether clinical features predicted copper accumulation. 34 ferrets, including 7 with necroinflammatory disease, 5 with hepatocellular carcinoma, 13 with non-necroinflammatory disease, and 9 with no hepatobiliary disease. Rhodanine-based digital copper quantification was validated by use of liver dually measured by atomic absorption spectroscopy and digital scanning (R2 = 0.98). Clinical features and hepatic copper scores and concentrations (dry weight liver) were compared between groups. Zonal copper distribution was determined. Hepatic copper concentration was strongly correlated with copper scores (ρ = 0.88). Ferrets with hepatobiliary disease were significantly older and had significantly higher serum alkaline phosphatase and γ-glutamyltransferase activities and creatinine concentrations. Centrilobular copper accumulated in 23 of 34 (64%) ferrets with (n = 15) and without (8) hepatobiliary disease. Median copper concentrations were not significantly different between ferrets with and without hepatobiliary disease but were significantly higher within neoplastic hepatic tissue in ferrets with hepatocellular carcinoma. Hepatic copper concentrations exceeded feline (> 180 µg/g) and canine (> 400 µg/g) reference limits in 19 and 9 ferrets, respectively. Hepatic copper > 1,000 µg/g occurred in 5 ferrets with and 2 without hepatobiliary disease. Clinical features did not predict copper accumulation. Rhodanine-based digital copper quantification and qualitative copper scoring discerned liver copper accumulation in ferrets. Ferrets with and without hepatobiliary disease displayed a propensity for centrilobular hepatic copper accumulation of uncertain clinical importance. Clinical and clinicopathologic features could not exclusively implicate pathologic copper accumulation.

474 Comparison Between Copper Sulfate and Dicopper Oxide on Body Weight and Copper Accumulation on Growing Pigs

Abstract There are several Cu sources in the market that have different effects on pigs. We hypothesized that supplementing therapeutic doses of Cu(I)oxide (Cu2O) in diets for growing pigs improves body weight (BW), bone mineralization, and reduces Cu accumulation in liver than supplementing pigs with Cu sulfate (CuSO4). Two-hundred growing pigs (initial BW: 11.5 ± 0.98 kg) were randomly allotted to 5 dietary treatments. Dietary treatments included the negative control (NC) diet without Cu supplementation, and 4 diets in which 125 or 250 mg/kg of Cu from CuSO4 or Cu2O were added to the NC diet. The experiment was divided into 4 phases. Pig weights were recorded on d 1 and at the end of each phase. Eight pigs per treatment were sacrificed last d of phases 1 and 4 to obtain samples of liver, spleen, and the right metacarpal. Pigs fed diets containing 250 mg/kg of Cu2O had greater (P < 0.05) BW at the end of phases 1 and 2 than pigs fed the NC diet, and tended (P < 0.10) to have greater BW at the end of phases 3 and 4 than pigs fed the other diets. Copper accumulation in liver and spleen increased with Cu dose, but at the end of phase 1, pigs fed 250 mg/kg CuSO4 had greater (P < 0.05) Cu concentration in liver and spleen than pigs fed 250 mg/kg Cu2O. Pigs fed diets containing 250 mg/kg Cu2O had greater (P < 0.05) quantities of bone ash and greater (P < 0.05) concentrations of Ca, P, and Cu in bone ash than pigs fed the NC diets or diets containing CuSO4. Therefore, supplementing diets for growing pigs with therapeutic doses of Cu2O improves BW and bone mineralization with less Cu accumulation in liver compared with pigs fed diets containing CuSO4.

Zeolitin (Clinoptilolite) Tilapiya (Oreocromis niloticus)’da Bakır Toksisitesi Üzerine Koruyucu Etkisi

In this study, the protective effect of zeolite added to water on tilapias exposed to sub-lethal concentration of copper was investigated. Treatments were copper, copper + zeolite, zeolite and control. During the experiment, fish growth by weight and length, copper accumulation in liver, and muscle protein ratios were measured. BUN, LDH, glucose, cholesterol, and triglyceride parameters of blood were also measured by taken monthly blood samples. The greatest increase in weight was observed in zeolite treatment by 68.8%. Liver copper accumulations were 12.6; 10.8; 1.27 and 1.33 ppm for the copper, copper + zelite, zeolite and control treatment, respectively. Although, BUN, LDH, cholesterol of copper + zeolite treatment were lower, triglyceride and glucose levels were higher comparing to control group (p

Inhibition of ASIC1a-Mediated ERS Improves the Activation of HSCs and Copper Transport Under Copper Load.

Hepatolenticular degeneration (HLD) is an autosomal recessive genetic disease caused by the toxic accumulation of copper in the liver. Excessive copper will disrupt the redox balance in cells and tissues, causing ischemia, hypoxia, and inflammation. Acid-sensitive ion channel 1a is a cationic channel activated by extracellular acid and allowing Ca2+ and Na+ to flow into cells. Its expression appears in inflammation, arthritis, fibrotic tissue, and damaged environment, but its role in hepatolenticular degeneration has not been studied. This study established a Wistar rat model of high copper accumulation and used CuSO4 to induce the activation of HSC-T6 in an in vitro experiment. In vivo, Wistar rats were examined to determine the serum copper concentration, serum ALT and AST activities, and liver copper accumulation, and liver tissue HE staining and immunohistochemical analyses were conducted. The expression of ASIC1a, α-SMA, Collagen-Ι, GRP78, XBP1, ATP7B, and CCS were detected. Besides, immunofluorescence technology can detect the expression of the phosphorylated protein in vitro. It is suggested that ASIC1a is involved in the quality control of the endoplasmic reticulum, which degrades mutant ATP7B and increases the accumulation of copper. After blocking or silencing the expression of ASIC1a, ELISA can detect the level of inflammatory factors, the expression of endoplasmic reticulum stress-related factors, and ATP7B was improved in a higher copper environment reduction of copper deposition was observed in liver Timm’s staining. Collectively, we conclude that ASIC1a is involved in the HSC activation induced by copper accumulation and promotes the occurrence of hepatolenticular fibrosis.

Inclusion of dicopper oxide instead of copper sulfate in diets for growing-finishing pigs results in greater final body weight and bone mineralization, but reduced accumulation of copper in the liver.

An experiment was conducted to test the hypothesis that inclusion of Cu oxide (Cu2O) in diets for growing-finishing pigs improves body weight (BW) and bone mineralization, and reduces accumulation of Cu in the liver compared with pigs fed diets containing Cu sulfate (CuSO4). Two hundred growing pigs (initial BW: 11.5 ± 0.98 kg) were allotted to a randomized complete block design with 2 blocks of 100 pigs, 5 dietary treatments, 5 pigs per pen, and a total of 8 pens per treatment. Treatments included the negative control (NC) diet that contained 20 mg Cu/kg, and 4 diets in which 125 or 250 mg Cu/kg from CuSO4 or Cu2O were added to the NC diet. The experiment was divided into 4 phases and concluded when pigs reached market weight. Pig weights were recorded on day 1 and at the end of each phase and feed provisions were recorded throughout the experiment. On the last day of phases 1 and 4, 1 pig per pen was sacrificed to obtain samples of liver and spleen tissue, and the right metacarpal was collected. Results indicated that pigs fed diets containing 250 mg Cu/kg from CuSO4 had greater BW at the end of phases 1 and 2 than pigs fed NC diets. Pigs fed diets containing 250 mg Cu/kg from Cu2O had greater (P < 0.05) BW at the end of phases 1, 2, 3, and 4 compared with pigs fed NC diets, and these pigs also had greater BW at the end of phases 3 and 4 than pigs fed all other diets. Pigs fed the diets with 250 mg Cu/kg tended to have greater (P < 0.10) feed intake than pigs fed the NC diet at the end of phase 2, and for the overall experimental period, pigs fed diets containing 250 mg Cu/kg from Cu2O had greater (P < 0.05) feed intake than pigs on all other treatments. However, no differences in gain:feed ratio were observed among treatments. Copper accumulation in liver and spleen increased with Cu dose, but at the end of phase 1, pigs fed 250 mg Cu/kg from CuSO4 had greater (P < 0.05) Cu concentration in liver and spleen than pigs fed 250 mg Cu/kg from Cu2O. Pigs fed diets containing 250 mg Cu/kg from Cu2O had greater (P < 0.05) quantities of bone ash and greater (P < 0.05) concentrations of Ca, P, and Cu in bone ash than pigs fed NC diets or the 2 diets containing CuSO4, but Zn concentration in bone ash was less (P < 0.05) in pigs fed diets containing 250 mg Cu/kg from Cu2O. To conclude, supplementing diets for growing pigs with Cu2O improves growth performance and bone mineralization with less Cu accumulation in liver compared with pigs fed diets containing CuSO4.

COMMD1 Exemplifies the Power of Inbred Dogs to Dissect Genetic Causes of Rare Copper-Related Disorders.

Simple SummaryResearch on rare diseases has specific problems, such as low or small patient groups, limited public awareness, and limited financial support. By definition, a rare disease affects not more than 50 per 100,000 individuals, but with over 6000 unique, rare diseases, more than 300 million people are affected worldwide. Especially, genetic screens are difficult to perform for rare diseases. Due to selective inbreeding in dogs, often these rare diseases present at high frequency in specific dog breeds. This paper in the special issue on “(epi) genetic disorders in companion animals” describes an example of how a novel gene was found that regulates copper accumulation in the liver in a specific dog breed, the Bedlington terriers, and describes an example of how gene products titrate each other’s function on the liver copper accumulation in Labrador retrievers. These two examples clearly show the power in dog genetics for both veterinary and human medicine. Although inbreeding is under great societal scrutiny due to its consequential large number of inherited diseases, dog genetics will directly positively influence animal welfare, in addition to basic knowledge of biochemical regulation systems, and lastly, it will be beneficial for people suffering from rare diseases.Wilson’s Disease is a rare autosomal recessive disorder in humans, often presenting with hepatic copper overload. Finding the genetic cause of a rare disease, especially if it is related to food constituents like the trace element copper, is a Herculean task. This review describes examples of how the unique population structure of in-bred dog strains led to the discovery of a novel gene and two modifier genes involved in inherited copper toxicosis. COMMD1, after the discovery in 2002, was shown to be a highly promiscuous protein involved in copper transport, protein trafficking/degradation, regulation of virus replication, and inflammation. Mutations in the ATP7A and ATP7B proteins in Labrador retrievers and Dobermann dogs resulted in a wide variation in hepatic copper levels in these breeds. To our knowledge, numerous dog breeds with inherited copper toxicosis of unknown genetic origin exist. Therefore, the possibility that men’s best friend will provide new leads in rare copper storage diseases seems realistic.

Genotype-phenotype variable correlation in Wilson disease: clinical history of two sisters with the similar genotype

BackgroundWilson disease (WD) is an Autosomal-Recessive disorder due to mutations of ATP7B gene on chromosome 13q14.3. Inadequate protein function leads to low ceruloplasmin blood levels and copper accumulation in liver, basal ganglia and chornea. Main clinical manifestations are hypertransaminasemia, tremors, dysarthria, dystonia and psychiatric symptoms. The phenotypic variability in WD is considerable and its onset can be heterogeneous: the most common type in childhood is the hepatic involvement, followed by the neurological one or others. The presence of a genotype-phenotype correlation has not yet been fully demonstrated. The phenotypic variability may be explained by the intervention of other modifier genes regulating copper metabolism in the presence of mutations ATP7B.Case presentationA streaking phenotypic variability was observed in two Sicilian sisters carrying the same genotype for ATB7B gene [c.3207C > A / c.3904-2A > G]. Although both started to present signs at age 10 years, onset was characterized by neurological signs in the first (tremors, motor incoordination, language and cognitive impairment), while liver involvement has been the only sign in the other. They started the same chelation therapy. After a 20-year follow-up the former is severely affected (MRI evidence of basal ganglia copper deposits and hyperchogenic liver, thrombocytopenia), while the latter presents only a moderate liver enlargement. In literature, the splice mutation c.3904-2A > G is also reported in Egypt population, associated with acute liver failure or chronic hepatic disease, and it could be typical of Mediterranean area, not being reported in other geographical zones.ConclusionBased on our clinical experience in Eastern Sicily, there is a considerable phenotypic variability in WD, even in the presence of an identical genotype. The mutation c.3904-2A > G could be associated with this phenotypic variability in Mediterranean population, but further studies should be conducted. This condition could be explained by the intervention of modifier genes regulating copper metabolism in the presence of defective ATP7B protein function. Further investigations on their role by Next Generation Sequencing or Whole Exome Analysis might have a profound impact on patients’ management and in particular on therapy.

Wilson’s Disease in Children : An Update

Wilson’s Disease is an autosomal recessive disorder of copper metabolism due to ATP7B gene defect. This defect result in progressive toxic accumulation of copper in liver, CNS, cornea, skeletal system and other organs. Clinical presentations of Wilson’s disease (WD) in childhood ranges from asymptomatic liver disease to cirrhosis or acute liver failure, whereas neurological and psychiatric symptoms are rare. The basic diagnostic approach includes serum ceruloplasmin and 24-hour urinary copper excretion. Final diagnosis of WD can be established using a diagnostic scoring system based on symptoms, biochemical tests assessing copper metabolism, and molecular analysis of mutations in the ATP7B gene. Pharmacological treatment is life-long and aims at removal of copper excess by chelating agents as D-penicillamine, trientine or inhibition of intestinal copper absorption with zinc salts. Acute liver failure often requires liver transplantation. Genetic therapy and haplocyte transplantation represent future curative treatment for Wilson’s disease.

Metabolomics profiles of patients with Wilson disease reveal a distinct metabolic signature.

Wilson disease (WD) is characterized by excessive intracellular copper accumulation in liver and brain due to defective copper biliary excretion. With highly varied phenotypes and a lack of biomarkers for the different clinical manifestations, diagnosis and treatment can be difficult. The aim of the present study was to analyze serum metabolomics profiles of patients with Wilson disease compared to healthy subjects, with the goal of identifying differentially abundant metabolites as potential biomarkers for this condition. Hydrophilic interaction liquid chromatography-quadrupole time of flight mass spectrometry was used to evaluate the untargeted serum metabolome of 61 patients with WD (26 hepatic and 25 neurologic subtypes, 10 preclinical) compared to 15 healthy subjects. We conducted analysis of covariance with potential confounders (body mass index, age, sex) as covariates and partial least-squares analysis. After adjusting for clinical covariates and multiple testing, we identified 99 significantly different metabolites (FDR < 0.05) between WD and healthy subjects. Subtype comparisons also revealed significantly different metabolites compared to healthy subjects: WD hepatic subtype (67), WD neurologic subtype (57), WD hepatic-neurologic combined (77), and preclinical (36). Pathway analysis revealed these metabolites are involved in amino acid metabolism, the tricarboxylic acid cycle, choline metabolism, and oxidative stress. Patients with WD are characterized by a distinct metabolomics profile providing new insights into WD pathogenesis and identifying new potential diagnostic biomarkers.

Copper nanoparticles induced oxidation stress, cell apoptosis and immune response in the liver of juvenile Takifugu fasciatus

Copper nanoparticles (Cu NPs) are a new pollutant in aquaculture, representing a hazard to aquatic organisms. We investigated the effects of Cu NPs exposure on oxidative stress, apoptosis and immune response in an economically important model species, Takifugu fasciatus. The juvenile fish were exposed to control, 20 or 100 μg Cu NPs/L for 30 days. The growth of T. fasciatus was inhibited after Cu NPs exposure. Copper accumulation in liver increased with increasing Cu NPs dose. Oxidative stress indicators [malondialdehyde (MDA), total superoxide dismutase (T-SOD), catalase (CAT) and glutathione (GSH)], apoptosis index and activities of caspases (caspase-3, caspase-9) were all increased with the increase of Cu NPs concentration in liver. With an increase in Cu NPs dose, the activities of succinate dehydrogenase (SDH) and Na+-K+-ATPase as well as cytochrome c (Cyt-c) concentration in mitochondria decreased, accompanied by increased Cyt-c concentration in cytosol. Apoptosis-related gene expressions of p53, caspase-3, caspase-9 and Bax were increased with the increase of Cu NPs dose. However, the opposite result was found in Bcl2 expression. The physiological indicators of immune response [heat shock protein 70 (HSP70), heat shock protein 90 (HSP90), immunoglobulin M (IgM) and lysozyme (LZM)] as well as the mRNA levels of HSP70, HSP90, IgM and C-LZM were all increased after Cu NPs exposure. Our results will be helpful in understanding the mechanism of Cu NPs toxicity in T. fasciatus.

Three novel mutations in the ATP7B gene of unrelated Vietnamese patients with Wilson disease

BackgroundWilson disease (OMIM # 277900) is a autosomal recessive disorder characterized by accumulation of copper in liver and brain. The accumulation of copper resulting in oxidative stress and eventually cell death. The disease has an onset in a childhood and result in a significant neurological impairment or require lifelong treatment. Another serious consequence of the disease is the development of liver damage and acute liver failure leading to liver transplant. The disorder is caused by mutations in the ATP7B gene, encoding a P-type copper transporting ATPase.Case presentationWe performed genetic analysis of three unrelated patients from three different Vietnamese families. These patients had clinical features such as numbness of hands and feet, vomiting, insomnia, palsy, liver failure and Kayser–Fleischer (K–F) rings and were diagnosed with Wilson disease in the Human Genetics Department, Vietnam National Children’s Hospital. The entire coding region and adjacent splice sites of ATP7B gene were amplified and sequenced by Sanger method. Sequencing data were analyzed and compared with the ATP7B gene sequence published in Ensembl (ENSG00000123191) by using BioEdit software to detect mutations.ConclusionsIn this study, five mutations in the ATP7B gene were found. Among of these, three mutations were novel: c.750_751insG (p.His251Alafs*19) in exon 2, c.2604delC (p.Pro868Profs*5) in exon 11, and c.3077 T > A (p.Phe1026Tyr) in exon 14. Our results of the mutations associated with Wilson disease might facilitate the development of effective treatment plans.

Effects of Clinoptilolite on Copper Accumulation of Oreochromis niloticus

The copper accumulation in liver and gill tissues of Oreochromis niloticus, exposed to 2 ppm Cu&#x0D; and 1g/L clinoptilolite singly and to the same concentrations of their mixture over 24, 48, 72 and&#x0D; 96 hours was studied. ICP-AES spectrophotometer techniques were applied in determining tissue&#x0D; copper levels. Statistical evaluation of the experimental data was carried out by Student Newman&#x0D; Keul’s procedure. No mortality was observed during the experiments. Copper accumulation was&#x0D; lower in metal-clinoptilolite mixture group than metal singly group in gill tissue while no&#x0D; accumulation in both experimental groups in liver tissue (P&amp;lt;0.05). In addition, the copper level in&#x0D; the liver was lower in all experimental groups than in the control (P&amp;lt;0.05). Low Cu accumulation&#x0D; in gill tissue exposed in mixture groups can be explained by copper adsorption with chelating&#x0D; agent. The decrease of Cu reserves in the liver can be expressed by increase of copper-containing&#x0D; enzyme and protein synthesis.

Curcumin Effect on Copper Transport in HepG2 Cells.

Background and Objective: In Wilson’s disease, copper metabolism is impaired due to defective copper transporting protein ATP7B, resulting in copper accumulation in liver and brain and causing damage to liver and brain tissues. Published data suggest that one of the possible treatments for Wilson’s disease is curcumin—a compound found in the root of Curcuma longa. In this study, we tested whether curcumin affects copper transport and excretion in HepG2 hepatocytes carrying wildtype ATP7B. Materials and Methods: We examined the impact of 5 µM and 25 µM curcumin on the transport of copper in HepG2 cells incubated with 20 µM and 100 µM CuCl2, as well as copper excretion from cells. First, immunofluorescent staining and co-localization analysis were carried out in HepG2 cells using confocal laser scanning microscope and Nikon NIS Elements software. Second, a concentration of copper extracted into cell culture medium was determined using atomic absorption spectrometry. Results: The analysis of the co-localization between Golgi complex and ATP7B revealed that both 5 µM and 25 µM doses of curcumin improve the ability of liver cells to transport copper to plasma membrane at 20 µM CuCl2, but not at 100 µM CuCl2 concentration. However, atomic absorption spectrometry showed that curcumin rather promotes copper absorption into liver cell line HepG2 than excretion of it. Conclusions: Curcumin accelerates the transport of copper within liver cells, but does not promote copper excretion from HepG2 cells.

Chapter 5 - Pathogenesis of Wilson disease

Wilson disease is an autosomal-recessive disorder originating from a genetic defect in the copper-transporting ATPase ATP7B that is required for biliary copper secretion and loading of ceruloplasmin with copper. Impaired ATP7B function in Wilson disease results in excessive accumulation of copper in liver, brain, and other tissues. Toxic copper deposits may induce oxidative stress, modify expression of genes, directly inhibit proteins, and impair mitochondrial function, leading to hepatic, neuropsychiatric, renal, musculoskeletal, and other symptoms. Hepatocyte dysfunction initially manifests as steatosis and later may progress to other hepatic phenotypes such as acute liver failure, hepatitis, and fibrosis. In the brain, copper accumulates in astrocytes, leading to impairment of the blood-brain barrier and consequent damage to neurons and oligodendrocytes. Basal ganglia and brainstem are the brain regions with highest susceptibility to copper toxicity and their lesions lead to various combinations of movement and psychiatric disorders. This chapter will give an overview of the essential requirement of copper for biologic processes and the molecular mechanisms employed by cells to maintain their copper levels in a proper range. We will specify the physiologic functions of ATP7B and the consequences of its dysfunction and summarize the current knowledge on the pathogenesis of liver and neuropsychiatric disease. Finally, we will describe the consequences of copper overload in Wilson disease in other tissues.

Wilson disease in a Bangladeshi child: A case report

Wilson disease, also known as hepatolenticular degeneration results from improper metabolism of copper due to deficiency or low level of caeruloplasmin which causes excessive accumulation of copper in liver, brain, eyes and different organs. This is not a curable disease. The patient needs a lifelong treatment but early diagnosis can prevent significant damage to the critical organs. This article presents a case study on Wilson disease and the role of radiology in helping to diagnose the disease and monitor patients with this condition.Bangladesh Med J. 2016 Jan; 45 (1): 54-56

Methanobactin reverses acute liver failure in a rat model of Wilson disease.

In Wilson disease (WD), functional loss of ATPase copper-transporting β (ATP7B) impairs biliary copper excretion, leading to excessive copper accumulation in the liver and fulminant hepatitis. Current US Food and Drug Administration- and European Medicines Agency-approved pharmacological treatments usually fail to restore copper homeostasis in patients with WD who have progressed to acute liver failure, leaving liver transplantation as the only viable treatment option. Here, we investigated the therapeutic utility of methanobactin (MB), a peptide produced by Methylosinus trichosporium OB3b, which has an exceptionally high affinity for copper. We demonstrated that ATP7B-deficient rats recapitulate WD-associated phenotypes, including hepatic copper accumulation, liver damage, and mitochondrial impairment. Short-term treatment of these rats with MB efficiently reversed mitochondrial impairment and liver damage in the acute stages of liver copper accumulation compared with that seen in untreated ATP7B-deficient rats. This beneficial effect was associated with depletion of copper from hepatocyte mitochondria. Moreover, MB treatment prevented hepatocyte death, subsequent liver failure, and death in the rodent model. These results suggest that MB has potential as a therapeutic agent for the treatment of acute WD.

Copper toxicosis in non-COMMD1 Bedlington terriers is associated with metal transport gene ABCA12

Wilson’s disease, caused by a mutation in the ATP-ase 7B gene, is the only genetically characterised human disease with inhibition of biliary copper excretion and toxic copper accumulation in liver and occasionally brain. A similar copper toxicosis occurs in Bedlington terriers (CT) with liver damage only. Although CT has been associated with a defect in the COMMD1 gene (COMMD1 del/del), Bedlington terriers with CT and lacking this mutation are also recognised (non-COMMD1 del/del).A study was designed to identify any other gene polymorphisms associated with copper toxicity in Bedlington terriers employing genome wide association studies (GWAS) followed by deep sequencing of the candidate region. Blood for DNA analysis and liver for confirmation of the diagnosis was obtained from 30 non-COMMD1 del/del Bedlington terriers comprising equal numbers of CT-affected dogs and controls. DNA was initially subjected to GWAS screening and then further sequencing to target the putative mutant gene.The study has identified a significant disease association with a region on chromosome 37 containing identified SNP’s which are highly significantly associated with non-COMMD1 del/del Bedlington terrier CT. This region contains the ABCA12 gene which bears a close functional relationship to ATP-ase 7B responsible for Wilson’s disease in man.

Relation of Copper Toxicosis in Dogs and Wilson Disease to the Appearance of a Small Copper Carrier (SCC) in Blood Plasma and Urine

The main route for copper excretion in mammals is via the bile, little exiting through urine. In Wilson disease, biliary excretion is prevented by lack of an active form of ATP7B, which permits copper entry into bile. This leads to copper accumulation and severe liver toxicosis. Dogs tend to have the same problem, with much higher liver copper levels than other mammals. Many die of liver copper toxicosis. As in Wilson disease, Atp7b‐/‐ mice excrete high levels of copper in urine. Excretion is in the form of a 1.5 kDa SCC. We now have evidence that the same SCC exists in the blood plasma of humans, mice and dogs. Normally, it is bound to larger proteins, but large amounts of free SCC occur in the plasma of Atp7b‐/‐ mice, and in some dogs. SCC can be released from larger proteins by EDTA and accounts for ~10% of the total copper in human plasma. SCC is also released by EDTA in plasma from dogs and mice, including those with “free” SCC. FPLC‐SEC preliminary data suggest SCC is riding on proteins &gt;200kDa. Dog ceruloplasmin is also unusual, eluting as a much larger protein, although of normal size in SDS‐PAGE. We conclude that SCC may offer an alternative route for copper excretion that can be mobilized in some mammals in response to liver copper accumulation, and that the study of dog plasma may reveal additional information about copper metabolism not detected as easily in other species.

Genetic, metabolic and cellular factors influencing intracellular localization of the Wilson disease protein, ATP7B

Background Wilson disease (WD) is a disorder of copper accumulation in liver and brain caused by mutations in the coppertransporting ATPase ATP7B that affects 1 in 5000 live births. Under basal conditions, ATP7B protein localizes to the trans-Golgi network (TGN) but traffics to vesicles in response to high copper. The purpose of the study is to identify genetic, metabolic and regulatory factors that regulate ATP7B function and localization to maintain normal copper homeostasis in cells. The study is divided into three parts, (a) Role of copper in normal protein folding and its ER exit, (b) Role of regulatory phosphorylation of ATP7B in its trafficking from TGN to vesicles (c) Interaction of ATP7B with regulatory proteins in its trafficking route.

A novel ATP7B gene mutation in a liver failure patient with normal ceruloplasmin and low serum alkaline phosphatase

Wilson's disease (WD) is a rare disorder of copper metabolism resulting in accumulation of copper in liver and other organs. We present a liver failure patient, who was misdiagnosed for two years, with normal ceruloplasmin and low serum alkaline phosphatase. Molecular testing revealed a novel p.Ala982Thr mutation within ATP7B gene. The pathology of liver sample showed a large amount of copper deposition in the hepatocytes and confirmed the diagnosis of WD. Our data highlighted the importance of molecular testing in the early diagnosis of atypical WD.