Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:1.16.3.1 (ceruloplasmin)
 5,074 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The trace metal copper (Cu) plays an essential role in biology as a cofactor for many enzymes that include Cu, Zn superoxide dismutase, cytochrome oxidase, ceruloplasmin, lysyl oxidase, and dopamine beta-hydroxylase. Consequently, Cu transport at the cell surface and the delivery of Cu to intracellular compartments are critical events for a wide variety of biological processes. The components that orchestrate intracellular Cu trafficking and their roles in Cu homeostasis have been elucidated by the studies of model microorganisms and by the characterizations of molecular basis of Cu-related genetic diseases, including Menkes disease and Wilson disease. However, little is known about the mechanisms for Cu uptake at the plasma membrane and the consequences of defects in this process in mammals. Here, we show that the mouse Ctr1 gene encodes a component of the Cu transport machinery and that mice heterozygous for Ctr1 exhibit tissue-specific defects in copper accumulation and in the activities of copper-dependent enzymes. Mice completely deficient for Ctr1 exhibit profound growth and developmental defects and die in utero in mid-gestation. These results demonstrate a crucial role for Cu acquisition through the Ctr1 transporter for mammalian Cu homeostasis and embryonic development.
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PMID:Essential role for mammalian copper transporter Ctr1 in copper homeostasis and embryonic development. 1139 Oct 5

We found a 4-year-old boy in the screened cohort, who showed a low ceruloplasmin (CP) in urine (17 ng/mg-creatinine) and in blood (0.6 mg/dl), but his urine copper was in the normal range. Furthermore this child was diagnosed as Wilson disease (WD) by genetic analysis. Although no significant correlation was observed between urine and blood levels of CP, it is conceivable that WD may be accompanied by very low concentration of urine CP.
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PMID:Studies of mass infant screening for Wilson disease by urinary ceruloplasmin. 1140 Jul 55

There is accumulating evidence that ceruloplasmin, a copper-containing protein with ferroxidase activity, plays an important role in iron metabolism. Reduction of ferroxidase activity secondary to ceruloplasmin deficiency may induce iron accumulation in various organs as the result of impaired iron transport. A 37-year-old man presented with intention tremor of the right hand. Liver function tests were almost normal, but parameters of trace elements were abnormal: hypocupremia, hypoceruloplaminemia, and hyperferritinemia. Imaging of the abdomen showed a cirrhotic liver with increased density. A diagnosis of the neurological form of Wilson disease was confirmed by copper deposits in the liver obtained by a blind biopsy, and the patient was diagnosed as compound heterozygous for ATP7B mutations. He was treated with 2500 mg/day trientine hydrochloride per os. The second examination was performed after 20 months of treatment. The treatment further reduced serum ceruloplasmin level from 8.9 to less than 4.0 mg/dl. Serum ferroxidase activity was as low as 70 U/l during treatment. Posttreatment liver histology became negative for copper but remained positive for iron. Copper X-rays from hepatocyte lysosomes were no longer detected, but the iron X-ray was still very high post treatment. Thus, microanalysis confirmed compound overload of copper and iron in this male patient with Wilson disease.
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PMID:Ultrastructural identification of iron and copper accumulation in the liver of a male patient with Wilson disease. 1147 73

Using the immunoblotting method, the synthesis of two copper-transporting P1-type ATPases, ATP7A (a candidate for the product of the Menkes disease gene) and ATP7B (presumed product of the Wilson disease gene), in the yolk sac cells of rat embryos at days 11 and 20 of embryogenesis was demonstrated. Concomitantly, yolk sac cells produce ceruloplasmin, a soluble copper-transporting glycoprotein, a proportion of which in secreted proteins progressively diminishes, attaining 5.2% at day 11 and 3.1% at day 20 of development. At different stages of embryogenesis, yolk sac cells synthesize two molecular forms of [14]C-ceruloplasmin, one of which is secreted towards the embryo, whereas the other, towards the decidual membrane. Two forms of ceruloplasmin secreted in polar directions differ in the rate of secretion. The role of the yolk sac as a key organ controlling the delivery and secretion of copper in the embryo during the postimplantation period is discussed.
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PMID:[The role of the yolk sac in copper metabolism during rat embryogenesis]. 1154 10

Metallothionein (MT) protects the body from both harmful non-essential and excessive essential metals. Copper (Cu) is an essential metal, and its concentration in the body is regulated at a constant level between excess and deficient ones. Cu accumulating in the livers of Wilson disease patients and its animal model, Long-Evans rats with a cinnamon-like coat color (LEC) rats, is in the form of Cu,Zn-MT, MT being an antioxidant. Contrary to the efficient production of MT in response to excessive accumulation of Cu in LEC rats, Cu-binding to MT only occurs marginally under normal conditions. However, the present study revealed that Cu binds to MT more with a severe Cu-deficiency. Namely, male C57BL/6J mice were fed a Cu-deficient diet (0.037 mg Cu/g) and deionized water containing trientine, and then the concentration and distribution of Cu were determined. It was suggested that the cessation of biliary excretion and limitation of the Cu supply to ceruloplasmin are the first responses on feeding of a Cu-deficient diet, followed by an increase in Cu-MT with maintenance of the Cu concentration in the liver. These results suggest that MT causes the recruitment of Cu in a Cu-deficient environment by sequestering Cu from degraded Cu-enzymes and delivering it to Cu chaperones.
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PMID:Roles of metallothionein in copper homeostasis: responses to Cu-deficient diets in mice. 1180 37

Wilson disease is an autosomal recessive inherited disorder of copper metabolism, characterized by the accumulation of copper in the body due to defective biliary copper excretion from hepatocytes. Recently, novel components involved in copper metabolism, including Menkes disease protein (ATP7A), Wilson disease protein (ATP7B), and copper chaperones, have been identified. It has been demonstrated that ATP7B functions in copper secretion into the plasma, coupled with ceruloplasmin synthesis and biliary copper excretion. However, the precise intracellular localization of ATP7B has been disputed. Various mutations of ATP7B have been reported in patients with Wilson disease, and investigations of genotype-phenotype correlations are now being conducted in the patients. These recent findings provide us with information on the molecular pathogenesis of Wilson disease, as well as the biological mechanisms of copper homeostasis. In this review, recent advances in this field are briefly summarized.
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PMID:Wilson disease. 1218 46

In an animal model of Wilson disease, Long-Evans rats with cinnamon-colored coat (LEC rats), copper (Cu) accumulates in the liver with age up to the onset of acute hepatitis owing to a hereditary defective transporter for the efflux of Cu, ATP7B. The plasma Cu concentration is low in LEC rats because of the excretion of apo-ceruloplasmin (apo-Cp). However, toward and after the onset of chronic hepatitis, plasma Cu concentration increases in the form of holo-Cp, while the liver Cu concentration is maintained at a constant level without the occurrence of fulminant hepatitis. In the present study, the material balance of Cu was studied in LEC rats with chronic hepatitis in order to elucidate the mechanisms underlying the increase of holo-Cp in plasma and the maintenance of Cu at a constant level in the liver. The relationship between the Cu concentration and ferroxidase activity of Cp was analyzed in the plasma of LEC rats of different ages and of Wistar rats fed a Cu-deficient diet for different durations. Cu was suggested to be delivered to Cp in an all-or-nothing manner, resulting in the excretion of fully Cu-occupied holo-Cp (Cu(6)-Cp) or totally Cu-unoccupied Cu(0)-Cp (apo-Cp), but not partially Cu-occupied Cu(n)-Cp (where n = 1-5). The increase of holo-Cp in acute and chronic hepatitis in LEC rats was explained by the delivery of Cu, accumulating in the non-metallothionein-bound form, to Cp outside the Golgi apparatus of the liver. The plasma Cu concentration and ferroxidase activity were proposed to be specific indicators of the appearance of non-metallothionein-bound Cu in the liver of LEC rats.
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PMID:Copper balance and ceruloplasmin in chronic hepatitis in a Wilson disease animal model, LEC rats. 1224 7

The presence of steatosis and inflammatory infiltrate in liver biopsies is essential for the diagnosis of non-alcoholic steatohepatitis (NASH). These findings are similar to those with alcoholic liver disease. However, in the NASH-situation alcohol doesn't play an important role. Risk factors for the development of NASH are obesity and diabetes. Most of the patients are clinically asymptomatic. This means, that a diagnosis of NASH is a diagnosis of exclusion: Viral induced, autoimmune, metabolic and toxic liver disease have to be excluded. The disease has a benign clinical course. The risk of cirrhosis is low. So far, there is no established treatment. Preliminary reports suggest a positive effect of weight-loss and ursodeoxycholic acid. Wilson's disease, a copper storage disorder, in which biliary copper excretion is reduced, is inherited as an autosomal recessive trait. Most patients with Wilson disease become symptomatic between the ages of 6 and 15. In about 90% of patients serum ceruloplasmin levels and serum copper concentrations are reduced. Copper excreation is increased. Histologic examination of liver biopsy specimens reveals fatty infiltration, Mallory bodies and ballooned glycogen nuclei, abnormalities which are also found in alcoholic liver disease. The definitive diagnostic parameter is the quantitative determination of liver copper content (> 250 micrograms/g dryweight). Untreated Wilson disease is always fatal. Lifelong treatment with anti-copper drugs are essential, D-penicillamine being the firstline therapy. Hereditary hemochromatosis (HH) is an iron overload disease inherited as an autosomal recessive trait. The frequency of the disease is high. The first symptoms usually can be found at the age of 20-50 years. Arthralgia develops in up to 50% of the patients. Many organs are involved, most often the liver. The organ is usually enlarged, transaminases are always moderately elevated. Laboratory findings disclose a marked elevation in serum ferritin and transferrin saturation. More than 80% of HH-patients are homozygous for the C282Y-mutation in the HFE-gene. The firstline treatment of HH is phlebotomy. Treatment is lifelong. When serum ferritin drops below 50 micrograms/l, the frequency of phlebotomy should be reduced (4-12 per year). If the patient already has cirrhosis, the risk of HCC is very high.
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PMID:[Rare, but important chronic liver diseases]. 1250 71

Copper transporting P-type ATPases, designated ATP7A and ATP7B, play an essential role in mammalian copper balance. Impaired intestinal transport of copper, resulting from mutations in the ATP7A gene, lead to Menkes disease in humans. Defects in a similar gene, the copper transporting ATPase ATP7B, result in Wilson disease. This ATP7B transporter has two functions: transport of copper into the plasma protein ceruloplasmin, and elimination of copper through the bile. Variants of ATP7B can be functionally assayed to identify defects in each of these functions. Tissue expression studies of the copper ATPases and their copper chaperone ATOX1 indicate that there is not complete overlap in expression. Other chaperones may be important for the transport of copper into ATP7A and ATP7B.
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PMID:Copper transporting P-type ATPases and human disease. 1253 60

Recent advances in molecular biology have made possible the identification of genetic defects responsible for Wilson's disease, Indian childhood cirrhosis and copper toxicosis in Long Evans Cinnamon rats, toxic milk mice, and Bedlington terriers. The Wilson's disease gene is localized on human chromosome 13 and codes for ATP7B, a copper transporting P-type ATPase. A genetic defect similar to that of Wilson's disease occurs in Long Evans Cinnamon rats and toxic milk mice. Familial copper storage disorders in Bedlington and West Highland white terriers are associated with early subclinical disease, and copper accumulation with subsequent liver injury culminating in cirrhosis. The canine copper toxicosis locus in Bedlington terriers has been mapped to canine chromosome region CFA 10q26. Recently, a mutated MURR1 gene was discovered in Bedlington terriers affected with the disease. Idiopathic childhood cirrhosis is biochemically similar to copper toxicosis in Bedlington terriers, but clinically much more severe. Both conditions are characterized by the absence of neurologic damage and Kayser-Fleisher rings, and normal ceruloplasmin levels. A recent study added North Ronaldsay sheep to the list of promising animal models to study Indian childhood cirrhosis. Morphologic similarities between the two conditions include periportal to panlobular copper retention and liver changes varying from active hepatitis to panlobular pericellular fibrosis, and cirrhosis. Certain copper-associated disorders, such as chronic active hepatitis in Doberman pinschers and Skye terrier hepatitis are characterized by copper retention secondary to the underlying disease, thus resembling primary biliary cirrhosis in humans. Copper-associated liver disease has increasingly being recognized in Dalmatians. Copper-associated liver diseases in Dalmatians and Long Evans Cinnamom rats share many morphologic features. Fulminant hepatic failure in Dalmatians is characterized by high serum activities of alanine aminotransferase and aspartate aminotransferase, and severe necrosis of centrilobular areas (periacinar, zone 3) hepatocytes. Macrophages and surviving hepatocytes contain copper-positive material. Liver disease associated with periacinar copper accumulation has also been described in Siamese cats. Many questions regarding copper metabolism in mammals, genetic background, pathogenesis and treatment of copper-associated liver diseases remain to be answered. This review describes the similarities between the clinico-pathological features of spontaneous copper-associated diseases in humans and domestic animals.
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PMID:Animal models of copper-associated liver disease. 1276 23


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