Aberrant copper metabolism and hepatic inflammation cause neurological manifestations in a mouse model of Wilson's disease.

Pathogenic germline mutations in the P-type copper-transporting ATPase (ATP7B) gene cause Wilson's disease (WD), a hereditary disorder characterized by disrupted copper metabolism. The Arg778Leu (R778L) mutation in exon 8 is prevalent among individuals with WD in East Asia and is associated with more severe phenotypes. In this study, we generated a WD mouse model harboring R778L mutation (R778L mice) using CRISPR/Cas9. R778L mice exhibit a range of pathological characteristics resembling those of patients with WD and the same point mutations, including aberrant copper metabolism, pathological cellular injury, inflammation, and severe hepatic fibrosis. At 3-5 months of age, these mice started to display neurological deficits in motor coordination and cognitive dysfunction, accompanied by increased expression of inflammatory cytokines in the central nervous system. Microglia in the striatum and cortex exhibit significant activation, shorter processes, and decreased branch points. However, the Cu2+ levels in the brain tissue of R778L mice did not differ significantly from those of wild-type mice. Notably, inhibition of hepatic inflammation with PJ34 or siNfkb markedly alleviated the deficiencies in cognitive performance and improved locomotor activity in R778L mice. Thus, this study establishes a novel murine model to investigate the pathophysiology of WD, highlights the liver-brain crosstalk responsible for neurological manifestations in individuals with WD caused by the R778L point mutation, and demonstrates the potential of modulating liver inflammation as a therapeutic strategy for alleviating the neurological manifestations of WD.

Wilson's disease in Sardinian population: The experience of a pediatric referral center.

BACKGROUND AND OBJECTIVES: Wilson's disease (WD) in children and adolescents is predominantly asymptomatic or oligo-symptomatic. The symptoms are nonspecific and difficult to distinguish from other hepatic or neuropsychiatric disorders. In this study, we present the experience of a pediatric referral center for WD diagnosis and treatment. PATIENTS AND METHODS: We retrospectively analyzed clinical and laboratory data from 99 patients with WD of Sardinian origin, including physical examination, laboratory biochemical testing, liver biopsy, and genetic analysis. RESULTS: Patients were prevalently oligo-symptomatic or asymptomatic. The median age of diagnosis was 8.78 years. Ceruloplasmin values were lower than normal values in all analyzed patients. Twenty-four-hour urinary copper levels were higher than 40 µg/24-h in 92/96 patients. In all analyzed patients with the exception of one, liver copper was higher than 250 µg/g of dry weight but all had >75 µg/g of dry weight. Statistical analysis showed correlation between the age at diagnosis, serum copper, and 24-h urinary copper. Correlation was also found between serum copper and 24-h urinary copper. Molecular analysis of ATP7B gene allowed complete characterization in all the analyzed patients. CONCLUSION: A high index of clinical suspicion and biochemical tests including liver tests, serum ceruloplasmin, and basal 24-h urinary copper excretion and genotype determination are key to WD diagnosis. The long experience that a referral center for WD possesses is an important factor in making WD diagnosis a more accurate process. Studies in animal models on WD could be used as a guide to further investigate the molecular mechanisms that regulate copper metabolism and influence the natural history of WD.

Wilson's Disease-Crossroads of Genetics, Inflammation and Immunity/Autoimmunity: Clinical and Molecular Issues.

Wilson's disease (WD) is a rare, autosomal recessive disorder of copper metabolism caused by pathogenic mutations in the ATP7B gene. Cellular copper overload is associated with impaired iron metabolism. Oxidative stress, cuproptosis, and ferroptosis are involved in cell death in WD. The clinical picture of WD is variable. Hepatic/neuropsychiatric/other symptoms may manifest in childhood/adulthood and even old age. It has been shown that phenotypic variability may be determined by the type of ATP7B genetic variants as well as the influence of various genetic/epigenetic, environmental, and lifestyle modifiers. In 1976, immunological abnormalities were first described in patients with WD. These included an increase in IgG and IgM levels and a decrease in the percentage of T lymphocytes, as well as a weakening of their bactericidal effect. Over the following years, it was shown that there is a bidirectional relationship between copper and inflammation. Changes in serum cytokine concentrations and the relationship between cytokine gene variants and the clinical course of the disease have been described in WD patients, as well as in animal models of this disease. Data have also been published on the occurrence of antinuclear antibodies (ANAs), antineutrophil cytoplasmic antibodies (ANCAs), anti-muscle-specific tyrosine kinase antibodies, and anti-acetylcholine receptor antibodies, as well as various autoimmune diseases, including systemic lupus erythematosus (SLE), myasthenic syndrome, ulcerative colitis, multiple sclerosis (MS), polyarthritis, and psoriasis after treatment with d-penicillamine (DPA). The occurrence of autoantibodies was also described, the presence of which was not related to the type of treatment or the form of the disease (hepatic vs. neuropsychiatric). The mechanisms responsible for the occurrence of autoantibodies in patients with WD are not known. It has also not been clarified whether they have clinical significance. In some patients, WD was differentiated or coexisted with an autoimmune disease, including autoimmune hepatitis or multiple sclerosis. Various molecular mechanisms may be responsible for immunological abnormalities and/or the inflammatory processes in WD. Their better understanding may be important for explaining the reasons for the diversity of symptoms and the varied course and response to therapy, as well as for the development of new treatment regimens for WD.

Copper Conundrum: Navigating Atypical Wilson's Disease Through Radiological Insights.

Wilson's disease is a rare genetic disorder characterized by abnormal copper metabolism due to mutations in the ATP-7B gene. This case report details the presentation of a 14-year-old male child exhibiting severe generalized dystonia, rigidity, myoclonic jerks, dysarthria, and excessive salivary drooling. During ophthalmic examination, Kayser-Fleischer rings were identified. Symmetrical hyperintensities in cortical and subcortical areas, including the basal ganglia and brainstem, were noted on brain magnetic resonance imaging (MRI). Additionally, diffusion restriction in the bilateral fronto-parietal region was observed. The diagnosis of Wilson's disease was confirmed through further diagnostic assessments, such as serum ceruloplasmin levels and urine copper excretion. Treatment was initiated with penicillamine, anticonvulsants, and supportive measures, resulting in partial recovery after a three-month follow-up period. This case emphasizes the significance of identifying atypical MRI brain findings in Wilson's disease, which aids in early diagnosis and appropriate management to prevent irreversible neurological damage.

Serum ceruloplasmin oxidase activity: A neglected diagnostic biomarker for Wilson disease.

BACKGROUND: Low serum ceruloplasmin concentration is considered robust marker for Wilson disease (WD) screening, measuring serum ceruloplasmin oxidase activity might be an even more valuable diagnostic tool, but it has not been sufficiently studied. METHODS: All patients who were assessed for serum ceruloplasmin oxidase activity between January 1, 2016, and September 2, 2019, were enrolled in this study. The diagnostic performance of serum ceruloplasmin oxidase activity was analyzed using receiver operating characteristic curve analysis (ROC), Spearman's rank correlation, and Mann-Whitney U test. RESULTS: Serum ceruloplasmin oxidase activity was significantly decreased in WD patients (0.87 U/L, IQR 0.61-1.54). The optimal cut-off of serum ceruloplasmin oxidase activity to identified WD is 7 U/L, with sensitivity and specificity of 97.03 % and 98.19 %, respectively. Furthermore, this study revealed a positive correlation between enzymatic and immunoreactive serum ceruloplasmin tests. As primary diagnostic methods, serum ceruloplasmin levels below the diagnostic cut-offs for either the enzymatic or immunoreactive tests were observed in 818 out of 842 WD patients (97.15 %). Compared with the presence of K-F rings in asymptomatic patients, the accuracy of serum ceruloplasmin tests was significantly higher (56.12 % VS 95.08 %). Moreover, the positive rate of cranial MRI in neurological patients was similar to the tests of serum ceruloplasmin (92.91 % VS 97.40 %). Moreover, 71 patients had ambiguous genetic results, complicating the diagnosis. However, serum ceruloplasmin tests successfully identified 65 out of these 71 patients (91.55 %). CONCLUSION: Serum ceruloplasmin oxidase activity has excellent performance in diagnosing WD, which should be widely used as preferred test in WD patients.

A Case of Wilson's Disease Suspected to Involve a Novel Genetic Mutation of ATP7B Gene, Requiring a Differential Diagnosis with Non-alcoholic Steatohepatitis.

A 19-year-old Japanese man was referred for a further evaluation of liver dysfunction. Despite the absence of symptoms or obesity, the liver biopsy results were consistent with non-alcoholic steatohepatitis. Subsequent investigations revealed low serum ceruloplasmin, increased urinary copper excretion, and a known mutation c.3809A>G (p.Asn1270Ser) in the copper-transporting enzyme P-type ATPase (ATP7B) gene, leading to a diagnosis of Wilson's disease. A previously unreported variant, i.e., c.3866A>T (p.Asp1289Val) was detected on the patient's other allele and was considered a novel mutation, classified as 'likely pathogenic' according to the American College of Medical Genetics guidelines.

[Genotype-phenotype relationship and genetics study of 115 cases with Wilson's disease].

Objective: To explore the genotype-phenotype relationship of Wilson's disease (WD) and further study the mutation spectrum in the ATP7B gene. Methods: The clinical data and genetic test results of 115 cases with WD diagnosed in the First Affiliated Hospital of Zhengzhou University from 2015 to 2022 were retrospectively analyzed. The rank sum test was used for quantitative data comparison, and χ(2) test was used for count data comparison. Multivariate logistic regression was used to analyze the relationship between patients' genotype and phenotype. Results: The onset of liver manifestations (hepatic type) accounted for 60.9%, neurological symptoms (cerebral type) for 13.0%, and mixed hepato-cerebral symptoms for 26.1%. Presymptomatic individuals (hepatic types) accounted for 62.9%. Next-generation sequencing- diagnosed WD cases accounted for 87.8%. Combined multiplex ligation-dependent probe amplification assay-diagnosed WD cases accounted for 89.6%. A single case with a detected pathogenic locus accounted for 10.4%. The diagnostic rate of WD by genetic testing combined with clinical data was 100%. A total of 76 ATP7B mutations were detected, and the top three mutation frequencies were c.2333G>T (p.Arg778Leu) (30.7%), c.2975C>T (p.Pro992Leu) (7.3%), and c.2621C>T (p.Ala874Val) (6.4%). The mutations were mainly distributed in exons 8, 11-13, and 15-18, accounting for more than 90% of the total mutations. Eight new mutations were found, including c.3724G>A (p.Glu1242Lys), c.3703G>C (p.Gly1235Arg), c.3593T>C (p.Val1198Ala), c.2494A>C (p.Lys832Gln), c.1517T>A (p.Ile506Lys), c.484G>T (p.Glu162Ter), c.1870-49A>G, and the missing of exons 10-21. Liver histopathology showed cellular edema, degeneration, inflammation, and necrosis, as well as a 42.8% copper staining positive rate. Genotype-phenotype analysis showed that the p.Arg778Leu mutation had higher alanine aminotransferase (ALT) levels than those carrying other mutations (P=0.024), while the homozygous mutation of p.Arg778Leu was associated with cerebral-type patients (P=0.027). Conclusion: Genetic testing plays an important role in the diagnosis of WD. p.Arg778Leu is the first high-frequency mutation in the Chinese population, and patients carrying it have higher ALT levels. The p.Arg778Leu homozygous mutation is prone to causing cerebral-type WD. This study expands the ATP7B gene mutation spectrum.

FoxO1 silencing in Atp7b-/- neural stem cells attenuates high copper-induced apoptosis via regulation of autophagy.

Wilson disease (WD) is a severely autosomal genetic disorder triggered by dysregulated copper metabolism. Autophagy and apoptosis share common modulators that process cellular death. Emerging evidences suggest that Forkhead Box O1 over-expression (FoxO1-OE) aggravates abnormal autophagy and apoptosis to induce neuronal injury. However, the underlying mechanisms remain undetermined. Herein, the aim of this study was to investigate how regulating FoxO1 affects cellular autophagy and apoptosis to attenuate neuronal injury in a well-established WD cell model, the high concentration copper sulfate (CuSO4, HC)-triggered Atp7b-/- (Knockout, KO) neural stem cell (NSC) lines. The FoxO1-OE plasmid, or siRNA-FoxO1 (siFoxO1) plasmid, or empty vector plasmid was stably transfected with recombinant lentiviral vectors into HC-induced Atp7b-/- NSCs. Toxic effects of excess deposited copper on wild-type (WT), Atp7b-/- WD mouse hippocampal NSCs were tested by Cell Counting Kit-8 (CCK-8). Subsequently, the FoxO1 expression was evaluated by immunofluorescence (IF) assay, western blot (WB) and quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Meanwhile, the cell autophagy and apoptosis were evaluated by flow cytometry (FC), TUNEL staining, 2,7-dichlorofluorescein diacetate (DCFH-DA), JC-1, WB, and qRT-PCR. The current study demonstrated a strong rise in FoxO1 levels in HC-treated Atp7b-/- NSCs, accompanied with dysregulated autophagy and hyperactive apoptosis. Also, it was observed that cell viability was significantly decreased with the over-expressed FoxO1 in HC-treated Atp7b-/- WD model. As intended, silencing FoxO1 effectively inhibited abnormal autophagy in HC-treated Atp7b-/- NSCs, as depicted by a decline in LC3II/I, Beclin-1, ATG3, ATG7, ATG13, and ATG16, whereas simultaneously increasing P62. In addition, silencing FoxO1 suppressed apoptosis via diminishing oxidative stress (OS), and mitochondrial dysfunction in HC-induced Atp7b-/- NSCs. Collectively, these results clearly demonstrate the silencing FoxO1 has the neuroprotective role of suppressing aberrant cellular autophagy and apoptosis, which efficiently attenuates neuronal injury in WD.

Wilson Disease in Children in the Eastern Region of Morocco: Analysis of 24 Cases.

Wilson's disease (WD), or "hepato-lenticular degeneration," is a rare genetic disorder of autosomal recessive inheritance causing toxic tissue accumulation of copper, mainly in the liver, brain, and cornea. Its phenotypic and genotypic heterogeneity characterizes it. This study aimed to clarify the clinical features and spectrum of Wilson's disease in children from the eastern region of Morocco and to study the evolutionary profile and survival in this population while discussing and highlighting the various diagnostic and therapeutic difficulties encountered in the management of WD in our context. This retrospective study encompassed 24 children diagnosed with Wilson's disease, selected from the gastroenterology-hepatology and pediatric nutrition units at Mohamed VI University Hospital in Oujda, Morocco, over a span of nine years, from January 2015 to November 2023. Our series results show 14 boys and 10 girls; the median age of discovery was 11 years, with extremes ranging from 18 months to 15 years. The consanguinity was found in 13 patients. Clinically, the edemato-ascitic syndrome was noted in 14 patients with an alteration of the general state; icterus was found in 13 patients; signs of portal hypertension were present in six patients; and neurological signs in seven cases. Skin manifestations occurred in three cases, and arthralgia in three cases. Six children were diagnosed on the occasion of a family screening. Biologically, hepatic cytolysis was found in 20 patients, with signs of hepatocellular failure in 15 cases. Hemolytic anemia was present in nine patients. Ceruloplasminemia was decreased in 21 patients and cupremia in 19 patients. Cupruria was increased in 22 cases. The Kayser-Fleicher ring was found in 10 cases. Abdominal ultrasound showed ascites in 16 patients, hepatomegaly in 1, splenomegaly in two cases, hepatosplenomegaly in five cases, and cirrhosis in two. MRI showed signal abnormalities in 11 patients. Therapeutically, D-penicillamine was initially introduced in 18 patients and zinc acetate in 6 patients. The evolution was favorable for 15 patients still followed up in the department. Three patients died of hepatocellular failure, and two died of hepatic encephalopathy. Four patients were lost to follow-up.

The physiological and pathophysiological roles of copper in the nervous system.

Copper is a critical trace element in biological systems due the vast number of essential enzymes that require the metal as a cofactor, including cytochrome c oxidase, superoxide dismutase and dopamine-ß-hydroxylase. Due its key role in oxidative metabolism, antioxidant defence and neurotransmitter synthesis, copper is particularly important for neuronal development and proper neuronal function. Moreover, increasing evidence suggests that copper also serves important functions in synaptic and network activity, the regulation of circadian rhythms, and arousal. However, it is important to note that because of copper's ability to redox cycle and generate reactive species, cellular levels of the metal must be tightly regulated to meet cellular needs while avoiding copper-induced oxidative stress. Therefore, it is essential that the intricate system of copper transporters, exporters, copper chaperones and copper trafficking proteins function properly and in coordinate fashion. Indeed, disorders of copper metabolism such as Menkes disease and Wilson disease, as well as diseases linked to dysfunction of copper-requiring enzymes, such as SOD1-linked amyotrophic lateral sclerosis, demonstrate the dramatic neurological consequences of altered copper homeostasis. In this review, we explore the physiological importance of copper in the nervous system as well as pathologies related to improper copper handling.

Phenotype and molecular characterization of Wilson's disease in Morocco.

BACKGROUND AND STUDY AIMS: In Morocco the prevalence of Wilson disease (WD) and the spectrum of mutations are not known. The aim of the present study was to estimate the prevalence of WD in Morocco, to evaluate the phenotype among a large cohort of WD patients, and to characterize ATP7B variants in a subgroup of WD patients. PATIENTS AND METHODS: We collected data from 226 patients admitted to five university hospital centers in Morocco between 2008 and 2020. The diagnosis was based on clinical manifestations, function tests and biochemical parameters. The genotype was characterized in 18 families diagnosed at the University Hospital Center of Marrakesh, by next generation sequencing. RESULTS: The mean annual prevalence in Morocco was 3.88 per 100,000 and the allele frequency was 0.15 %. Among the 226 patients included (121 males and 105 females), 196 were referred for a hepatic or neurological involvement and 30 were asymptomatic. The mean age at diagnosis was 13 ± 5.1 years (range: 5 - 42 years). Consanguinity was found in 63.3 % of patients. The mean duration of illness was 2.8 ± 1.9 years. Kayser-Fleischer rings were found in 131 (67.9 %) of 193 patients. Among the 196 symptomatic patients, 141/159 (88.7 %) had low serum ceruloplasmin (<0.2 g/L) and a high 24-hours urinary copper (>100 µg/day) was found in 173/182 (95.1 %) patients. The initial treatment was D-penicillamine in 207 patients, zinc acetate in five, zinc sulfate in five, and nine patients were not treated; 60/207 (29 %) patients have stopped treatment. A total of 72 patients died; the mortality rate was 31.9 %. Eight different ATP7B variants were identified among the 18 patients studied, of which two were novel (p.Cys1104Arg and p.Gln1277Hisfs*52), and six previously published (p.Gln289Ter, p.Cys305Ter, p.Thr1232Pro, p.Lys1020Arg, p.Glu583ArgfsTer25 and c.51+4A>T). All informative patients were homozygous for the disease-causing mutation. CONCLUSION: In Morocco, a high prevalence due to consanguinity and a high mortality rate due to the difficulty of diagnosis and lack of treatment were observed in WD patients. NGS sequencing identified new ATP7B variants in WD patients from Morocco.

Research progress in stem cell therapy for Wilson disease.

Wilson disease (WD), also known as hepatolenticular degeneration, is an autosomal recessive disorder characterized by disorganized copper metabolism caused by mutations in the ATP7B gene. Currently, the main treatment options for WD involve medications such as d-penicillamine, trientine hydrochloride, zinc acetate, and liver transplantation. However, there are challenges that encompass issues of poor compliance, adverse effects, and limited availability of liver sources that persist. Stem cell therapy for WD is currently a promising area of research. Due to the advancement in stem cell directed differentiation technology in vitro and the availability of sufficient stem cell donors, it is expected to be a potential treatment option for the permanent correction of abnormal copper metabolism. This article discusses the research progress of stem cell therapy for WD from various sources, as well as the challenges and future prospects of the clinical application of stem cell therapy for WD.

AP-1γ2 is an adaptor protein 1 variant required for endosome-to-Golgi trafficking of the mannose-6-P receptor (CI-MPR) and ATP7B copper transporter.

Selective retrograde transport from endosomes back to the trans-Golgi network (TGN) is important for maintaining protein homeostasis, recycling receptors, and returning molecules that were transported to the wrong compartments. Two important transmembrane proteins directed to this pathway are the Cation-Independent Mannose-6-phosphate receptor (CI-MPR) and the ATP7B copper transporter. Among CI-MPR functions is the delivery of acid hydrolases to lysosomes, while ATP7B facilitates the transport of cytosolic copper ions into organelles or the extracellular space. Precise subcellular localization of CI-MPR and ATP7B is essential for the proper functioning of these proteins. This study shows that both CI-MPR and ATP7B interact with a variant of the clathrin adaptor 1 (AP-1) complex that contains a specific isoform of the γ-adaptin subunit called γ2. Through synchronized anterograde trafficking and cell-surface uptake assays, we demonstrated that AP-1γ2 is dispensable for ATP7B and CI-MPR exit from the TGN while being critically required for ATP7B and CI-MPR retrieval from endosomes to the TGN. Moreover, AP-1γ2 depletion leads to the retention of endocytosed CI-MPR in endosomes enriched in retromer complex subunits. These data underscore the importance of AP-1γ2 as a key component in the sorting and trafficking machinery of CI-MPR and ATP7B, highlighting its essential role in the transport of proteins from endosomes.

Structure and mechanism of the human copper transporting ATPases: Fitting the pieces into a moving puzzle.

Human copper transporters ATP7B and ATP7A deliver copper to biosynthetic pathways and maintain copper homeostasis in the cell. These enzymes combine several challenges for structural biology because they are large low abundance membrane proteins with many highly mobile domains and long disordered loops. No method has yet succeeded in solving the structure of the complete fully functional protein. Still, X-ray crystallography, Cryo-EM and NMR helped to piece together a structure based model of the enzyme activity and regulation by copper. We review the structures of ATP7B and ATP7A with an emphasis on the mechanistic insights into the unique aspects of the transport function and regulation of the human copper ATPases that have emerged from more than twenty years of research.

A new Caenorhabditis elegans model to study copper toxicity in Wilson disease.

Wilson disease (WD) is caused by mutations in the ATP7B gene that encodes a copper (Cu) transporting ATPase whose trafficking from the Golgi to endo-lysosomal compartments drives sequestration of excess Cu and its further excretion from hepatocytes into the bile. Loss of ATP7B function leads to toxic Cu overload in the liver and subsequently in the brain, causing fatal hepatic and neurological abnormalities. The limitations of existing WD therapies call for the development of new therapeutic approaches, which require an amenable animal model system for screening and validation of drugs and molecular targets. To achieve this objective, we generated a mutant Caenorhabditis elegans strain with a substitution of a conserved histidine (H828Q) in the ATP7B ortholog cua-1 corresponding to the most common ATP7B variant (H1069Q) that causes WD. cua-1 mutant animals exhibited very poor resistance to Cu compared to the wild-type strain. This manifested in a strong delay in larval development, a shorter lifespan, impaired motility, oxidative stress pathway activation, and mitochondrial damage. In addition, morphological analysis revealed several neuronal abnormalities in cua-1 mutant animals exposed to Cu. Further investigation suggested that mutant CUA-1 is retained and degraded in the endoplasmic reticulum, similarly to human ATP7B-H1069Q. As a consequence, the mutant protein does not allow animals to counteract Cu toxicity. Notably, pharmacological correctors of ATP7B-H1069Q reduced Cu toxicity in cua-1 mutants indicating that similar pathogenic molecular pathways might be activated by the H/Q substitution and, therefore, targeted for rescue of ATP7B/CUA-1 function. Taken together, our findings suggest that the newly generated cua-1 mutant strain represents an excellent model for Cu toxicity studies in WD.

Late-onset Wilson Disease in a Patient Followed-up for Nonalcoholic Fatty Liver Disease.

A 73-year-old woman was referred to our hospital for persistent liver dysfunction. When the patient was 45 years old, her youngest sister had been diagnosed with Wilson disease (WD). The patient therefore underwent several family screening tests, all of which were unremarkable. She had an annual medical checkup and was diagnosed with liver dysfunction and fatty liver at 68 years old. A liver biopsy and genetic testing were performed, and she was diagnosed with WD; chelation therapy was then initiated. In patients with hepatic disorders and a family history of WD, multiple medical examinations should be conducted, as the development of WD is possible regardless of age.

Regulation of the apico-basolateral trafficking polarity of the homologous copper-ATPases ATP7A and ATP7B.

The homologous P-type copper-ATPases (Cu-ATPases) ATP7A and ATP7B are the key regulators of copper homeostasis in mammalian cells. In polarized epithelia, upon copper treatment, ATP7A and ATP7B traffic from the trans-Golgi network (TGN) to basolateral and apical membranes, respectively. We characterized the sorting pathways of Cu-ATPases between TGN and the plasma membrane and identified the machinery involved. ATP7A and ATP7B reside on distinct domains of TGN in limiting copper conditions, and in high copper, ATP7A traffics to basolateral membrane, whereas ATP7B traverses common recycling, apical sorting and apical recycling endosomes en route to apical membrane. Mass spectrometry identified regulatory partners of ATP7A and ATP7B that include the adaptor protein-1 complex. Upon knocking out pan-AP-1, sorting of both Cu-ATPases is disrupted. ATP7A loses its trafficking polarity and localizes on both apical and basolateral surfaces in high copper. By contrast, ATP7B loses TGN retention but retained its trafficking polarity to the apical domain, which became copper independent. Using isoform-specific knockouts, we found that the AP-1A complex provides directionality and TGN retention for both Cu-ATPases, whereas the AP-1B complex governs copper-independent trafficking of ATP7B solely. Trafficking phenotypes of Wilson disease-causing ATP7B mutants that disrupts putative ATP7B-AP1 interaction further substantiates the role of AP-1 in apical sorting of ATP7B.

The mutation spectrum and ethnic distribution of Wilson disease, a review.

Wilson's disease is a complicated medical condition caused by the accumulation of copper, mostly in the liver and brain. The genetic basis of Wilson's disease is attributed to the presence of pathogenic variants in the ATP7B copper-transporting gene, which prevents the excretion of copper through the biliary tract. To date, ATP7B remains the only identified gene that has been linked to the development of this disease. Our understanding of the disease has been associated with the identification of particular disease-causing variants that present specific impairments in copper transporters. It is crucial to identify the most frequent variant in terms of ethnicity to facilitate testing of its functionality. This study represents the initial comprehensive analysis of ATP7B variants, providing insights into the extensive range of disease-causing mutations. Here, we describe the 1275 distinct ATP7B variants documented so far, with particular emphasis on their regional and ethnic prevalence. The H1069Q missense variant is the most frequently reported in Europe, Northern America, and North Africa, whereas the R778L, C271*, and M645R variants are the most prevalent in the East Asian, Middle Eastern-South Asian, and South American populations, respectively. Acquiring such knowledge would facilitate the implementation of a selective mutation screening approach, targeting the most predominant variant identified within a specific ethnic group or geographic region for better diagnosis of the disease.

Nano-Mediated Molecular Targeting in Diagnosis and Mitigation of Wilson Disease.

Wilson disease, a rare genetic disorder resulting from mutations in the ATP7B gene disrupts copper metabolism, leading to its harmful accumulation in hepatocytes, the brain, and other organs. It affects roughly 1 in 30,000 individuals, with 1 in 90 being gene carriers. Beyond gene mutations, the disease involves complex factors contributing to copper imbalance. Ongoing research seeks to unravel intricate molecular pathways, offering fresh insights into the disease's mechanisms. Simultaneously, there is a dedicated effort to develop effective therapeutic strategies. Nanotechnology-driven formulations are showing promise for both treatment and early diagnosis of Wilson disease. This comprehensive review covers the entire spectrum of the condition, encompassing pathophysiology, potential biomarkers, established and emerging therapies, ongoing clinical trials, and innovative nanotechnology applications. This multifaceted approach holds the potential to improve our understanding, diagnosis, and management of Wilson's disease, which remains a challenging and potentially life-threatening disorder.

An association between ATP7B expression and human cancer prognosis and immunotherapy: a pan-cancer perspective.

BACKGROUND: ATP7B is a copper-transporting protein that contributes to the chemo-resistance of human cancer cells. It remains unclear what the molecular mechanisms behind ATP7B are in cancer, as well as its role in human pan-cancer studies. METHODS: Our study evaluated the differential expression of ATP7B in cancer and paracancerous tissues based on RNA sequencing data from the GTEx and TCGA. Kaplan-Meier and Cox proportional hazards regressions were used to estimate prognostic factors associated with ATP7B.The correlations between the expression of ATP7B and immune cell infiltration, tumor mutation burden, microsatellite instability and immune checkpoint molecules were analyzed. Co-expression networks and mutations in ATP7B were analyzed using the web tools. An analysis of ATP7B expression difference on drug sensitivity on tumor cells was performed using the CTRP, GDSC and CMap database. RESULTS: ATP7B expression differed significantly between cancerous and paracancerous tissues. The abnormal expression of ATP7B was linked to prognosis in LGG and KIRC. Infiltration of immune cells, tumor mutation burden, microsatellite instability and immunomodulators had all been linked to certain types of cancer. Cancer cells exhibited a correlation between ATP7B expression and drug sensitivity. CONCLUSION: ATP7B might be an immunotherapeutic and prognostic biomarker based on its involvement in cancer occurrence and development.