Menkes Disease Research Articles

Copper homeostasis and the ubiquitin proteasome system.

Copper is involved in many physiological pathways and important biological processes as a cofactor of several copper-dependent enzymes. Given the requirement for copper and its potential toxicity, intracellular copper levels are tightly controlled. Disturbances of human copper homeostasis are characterized by disorders of copper overload (Wilson's disease) or copper deficiency (Menkes disease). The maintenance of cellular copper levels involves numerous copper transporters and copper chaperones. Recently, accumulating evidence has revealed that components of the ubiquitin proteasome system (UPS) participate in the posttranslational regulation of these proteins, suggesting that they might play a role in maintaining copper homeostasis. Cellular copper levels could also affect the activity of the UPS, indicating that copper homeostasis and the UPS are interdependent. Copper homeostasis and the UPS are essential to the integrity of normal brain function and while separate links between neurodegenerative diseases and UPS inhibition/copper dyshomeostasis have been extensively reported, there is growing evidence that these two networks might contribute synergistically to the occurrence of neurodegenerative diseases. Here, we review the role of copper and the UPS in the development of Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis, and discuss the genetic interactions between copper transporters/chaperones and components of the UPS.

Health-Related Quality of Life and Family Functioning of Primary Caregivers of Children with Menkes Disease.

Menkes disease (MD; OMIM #309400) is a progressive neurodegeneration that results from abnormalities in the copper metabolism which are already present before birth. It is an extremely rare condition. The study was conducted to assess the quality of life of children with MD syndrome and the impact of the disease on family functioning. A cross-sectional questionnaire survey was used. The subjects were 16 parents of children with MD. The method used was the Paediatric Quality of Life Inventory and the PedsQL Family Impact Module and the author's own questionnaire. Quality of life (QOL) was 29.14 (SD = 14.73), with the lowest for physical functioning (M = 10.55; SD = 10.26) and highest for emotional functioning (M = 48.13; SD = 29.43). The highest score was on the family relationships domain (M = 56.25, SD = 20.38) and the cognitive functioning domain (M = 50.00, SD = 19.24) and the lowest was on the daily activities' domain (M = 32.29, SD = 20.38) and the physical functioning domain (M = 39.84, SD = 14.90). The analysis did not show statistically significant relationships between age (p = 0.193) and the number of epileptic seizures a week (p = 0.641) and the overall QOL of the children studied. No statistically significant relationships were found between treatment with copper histidine and the overall QOL of the children (p = 0.914) and in physical functioning (p = 0.927), emotional functioning (p = 0.706), and social functioning (p = 0.751). The presence of comorbidities did not have an influence on the overall QOL. MD has a moderate impact on the functioning of the families of the affected children. The age of the child, number of epileptic seizures a week, feeding method (oral feeding or feeding via a PEG tube), and treatment with copper histidine do not have a significant impact on the QOL of children with MD.

Presentation and Diagnosis of Pediatric X-Linked Hypophosphatemia

X-linked hypophosphatemia (XLH) is a rare type of hereditary hypophosphatemic rickets. Patients with XLH have various symptoms that lower their QOL as defined by HAQ, RAPID3, SF36-PCS, and SF36-MCS in adult patients and SF-10 and PDCOI in pediatric patients. Early diagnosis and treatment are needed to reduce the burden, but the condition is often diagnosed late in childhood. The present review aims to summarize the symptoms, radiological and biological characteristics, and long-term prognosis of pediatric XLH. Typical symptoms of XLH are lower leg deformities (age six months or later), growth impairment (first year of life or later), and delayed gross motor development with progressive lower limb deformities (second year of life or later). Other symptoms include dental abscess, bone pain, hearing impairment, and Chiari type 1 malformation. Critical, radiological findings of rickets are metaphyseal widening, cupping, and fraying, which tend to occur in the load-bearing bones. The Rickets Severity Score, validated for XLH, is useful for assessing the severity of rickets. The biochemical features of XLH include elevated FGF23, hypophosphatemia, low 1,25(OH)2D, and elevated urine phosphate. Renal phosphate wasting can be assessed using the tubular maximum reabsorption of phosphate per glomerular filtration rate (TmP/GFR), which yields low values in patients with XLH. XLH should be diagnosed early because the multisystem symptoms often worsen over time. The present review aims to help physicians diagnose XLH at an early stage.

Atp7b-dependent choroid plexus dysfunction causes transient copper deficit and metabolic changes in the developing mouse brain.

Copper (Cu) has a multifaceted role in brain development, function, and metabolism. Two homologous Cu transporters, Atp7a (Menkes disease protein) and Atp7b (Wilson disease protein), maintain Cu homeostasis in the tissue. Atp7a mediates Cu entry into the brain and activates Cu-dependent enzymes, whereas the role of Atp7b is less clear. We show that during postnatal development Atp7b is necessary for normal morphology and function of choroid plexus (ChPl). Inactivation of Atp7b causes reorganization of ChPl' cytoskeleton and cell-cell contacts, loss of Slc31a1 from the apical membrane, and a decrease in the length and number of microvilli and cilia. In ChPl lacking Atp7b, Atp7a is upregulated but remains intracellular, which limits Cu transport into the brain and results in significant Cu deficit, which is reversed only in older animals. Cu deficiency is associated with down-regulation of Atp7a in locus coeruleus and catecholamine imbalance, despite normal expression of dopamine-β-hydroxylase. In addition, there are notable changes in the brain lipidome, which can be attributed to inhibition of diacylglyceride-to-phosphatidylethanolamine conversion. These results identify the new role for Atp7b in developing brain and identify metabolic changes that could be exacerbated by Cu chelation therapy.

Prediction of Surgical Outcomes of Radial Polydactyly From the Wassel-Flatt Type and Symmetry of Duplication.

The Wassel classification is commonly used for cases of radial polydactyly but has not been used to predict surgical outcomes. This study aimed to investigate the predictive factors of surgical outcomes using the Wassel type and symmetry of duplication. Forty-five patients with 47 radial polydactylies were reviewed using the Japanese Society for Surgery of the Hand (JSSH) scores 4.6 years after minor thumb excision and reconstructive surgery. The symmetry index was defined as the metaphyseal width ratio of the minor thumb to the dominant thumb. The relationships between the JSSH scores and operation age, sex, side, follow-up duration, Wassel type, symmetric index, divergent angle, and joint angulation were analyzed by linear regression. The mean JSSH score of the 47 thumbs was 18.3 points (range, 15-20). Five thumbs had fair or poor outcomes (scores <17), all of which were Wassel type IV. The hypoplastic type had a better JSSH score (19.4) than other Wassel types. The symmetric index had a negative relationship with JSSH scores, especially for Wassel type IV (r=-0.68, P =0.001). Linear regression revealed that the symmetric index was the only independent factor significantly associated with JSSH scores among Wassel type IV polydactylies ( P <0.05). The receiver operating characteristic curve suggested a symmetric index <0.74 could predict good or excellent outcomes. The symmetry of the 2 duplicated thumbs is an important factor for surgical outcomes. The Wassel type IV polydactylies with a symmetric index >0.74 are at greater risk of fair or poor outcomes after excision and reconstruction, and further studies are warranted to confirm whether the Bilhaut-Cloquet procedure is a good choice. Level IV-Case-control study.

Copper and Ceruloplasmin Tests for Children With Global Developmental Delay and Intellectual Disability

&#x0D; No evidence was identified regarding the diagnostic test accuracy or clinical utility of copper and ceruloplasmin tests compared to other tests or criteria to detect Wilson disease and Menkes disease in children with global development delay and intellectual disability that met the criteria for this review.&#x0D; No evidence-based guidelines were found on the use of copper and ceruloplasmin tests for children with global developmental delay and intellectual disability that met the criteria for this review.&#x0D;

Massive thrombosis in internal jugular phlebectasia in Menkes disease.

Massive thrombosis in internal jugular phlebectasia in Menkes disease.

An ESIPT solvatochromic fluorescent and colorimetric probe for sensitive and selective detection of copper ions in environmental samples and cell lines.

Copper is one of the most important transition metals in our body for various physiological functions. An imbalance in the homeostasis of copper in our body can lead to various neurological disorders such as Alzheimer's disease, Parkinson's, and Menkes disease. As a result, there is a need for the detection of excess copper present in the environment and the human system. In this work, we have designed a quinoline-based fluorescent/colorimetric probe (QHS) for rapid and selective detection of copper ions via quenching of fluorescence/color change from yellow to peach which is visible to the naked eye. The probe displayed high selectivity towards copper(II), i.e., Cu(II) in the presence of different metal analytes in water samples. The sensing mechanism of the probe was confirmed by NMR, HRMS, IR spectroscopy, and SEM. The detection limit of Cu(II) ions was found to be 0.493 μM which is lower than the tolerable limit of copper (20 μM) in drinking water as per the EPA. The probe was also utilized for the visualization of Cu(II) in cell lines. The probe was also demonstrated for its application in real-time detection of aqueous samples using portable paper strips.

Esencijalni metali prisutni u tragovima u organizmu u zdravlju i bolesti

Essential trace metals (Fe, Zn, Cu, Mn, Mo, Co) are involved in high number of physiological and metabolic activities and therefore have a substantial role in organisms. Thus, their balance is tightly regulated by levels of absorption, transport, and storage in the organism. They can alter human health in both deficiency and overload conditions. On one hand, deficiency health problems are due to reduction of their physiological activities. On the other hand, Fe, Cu and Co are redox active metals and their increase can cause severe tissue damage through oxidative stress. Numerous well-established diseases like iron and copper deficiency anemia, hemochromatosis, Menkes and Wilson disease, acrodermatitis enteropathica are consequence of essential metal alterations. Nowadays, trace metals alterations are also found to be implicated in neurodegenerative disease, cancers, atherosclerosis, and diabetes. Those diseases represent enormous health problems in contemporary society and trace metals might help to further elucidate their pathogenesis and potentially even treatment. In the present study, essential trace metals kinetic and physiology are reviewed, as well as their roles in disease pathophysiology.

Can the level of copper in the hippocampus witness type-II diabetes versus Alzheimer's disease?

Copper is an essential trace metal ion involved in many key physiological processes and is the co-factor of the related enzymes, including the cytochrome c oxidase of the respiratory chain and the superoxide dismutases that takes part in the fight against oxidative stress. As for most of other trace elements, a proper copper homeostasis is crucial for a good health.1 Copper deficiency or excess represents pathologic conditions, as exemplified by the two genetic disorders, Menkes and Wilson diseases corresponding to a failure in copper absorption and distribution and to a failure in copper excretion, respectively.

Fatal congenital copper transport defect caused by a homozygous likely pathogenic variant of SLC31A1.

Known hereditary human diseases featuring impaired copper trafficking across cellular membranes involve ATP7A (Menkes disease, occipital horn disease, X-linked spinal muscular atrophy type 3) and ATP7B (Wilson disease). Herein, we report a newborn infant of consanguineous parents with a homozygous pathogenic variant in a highly conserved sequence of SLC31A1, coding for the copper influx transporter 1, CTR1. This missense variant, c.236T > C, was detected by whole exome sequencing. The infant was born with pulmonary hypoplasia and suffered from severe respiratory distress immediately after birth, necessitating aggressive mechanical ventilation. At 2 weeks of age, multifocal brain hemorrhages were diagnosed by cerebral ultrasound and magnetic resonance imaging, together with increased tortuosity of cerebral arteries. Ensuing seizures were only partly controlled by antiepileptic drugs, and the infant became progressively comatose. Laboratory investigations revealed very low serum concentrations of copper and ceruloplasmin. No hair shaft abnormalities were detected by dermatoscopy or light microscopic analyses of embedded hair shafts obtained at 4 weeks of life. The infant died after redirection of care and elective cessation of invasive mechanical ventilation at 1 month of age. This case adds SLC31A1 to the genes implicated in severe hereditary disorders of copper transport in humans.

Decreased Expression of the Slc31a1 Gene and Cytoplasmic Relocalization of Membrane CTR1 Protein in Renal Epithelial Cells: A Potent Protective Mechanism against Copper Nephrotoxicity in a Mouse Model of Menkes Disease.

Kidneys play an especial role in copper redistribution in the organism. The epithelial cells of proximal tubules perform the functions of both copper uptake from the primary urine and release to the blood. These cells are equipped on their apical and basal membrane with copper transporters CTR1 and ATP7A. Mosaic mutant mice displaying a functional dysfunction of ATP7A are an established model of Menkes disease. These mice exhibit systemic copper deficiency despite renal copper overload, enhanced by copper therapy, which is indispensable for their life span extension. The aim of this study was to analyze the expression of Slc31a1 and Slc31a2 genes (encoding CTR1/CTR2 proteins) and the cellular localization of the CTR1 protein in suckling, young and adult mosaic mutants. Our results indicate that in the kidney of both intact and copper-injected 14-day-old mutants showing high renal copper content, CTR1 mRNA level is not up-regulated compared to wild-type mice given a copper injection. The expression of the Slc31a1 gene in 45-day-old mice is even reduced compared with intact wild-type animals. In suckling and young copper-injected mutants, the CTR1 protein is relocalized from the apical membrane to the cytoplasm of epithelial cells of proximal tubules, the process which prevents copper transport from the primary urine and, thus, protects cells against copper toxicity.

Menkes Disease in an Infant who Presented with Recurrent Infections

Menkes Disease in an Infant who Presented with Recurrent Infections

Elesclomol elevates cellular and mitochondrial iron levels by delivering copper to the iron import machinery

Copper (Cu) and iron (Fe) are redox-active metals that serve as cofactors for many essential cellular enzymes. Disruption in the intracellular homeostasis of these metals results in debilitating and frequently fatal human disorders, such as Menkes disease and Friedreich’s ataxia. Recently, we reported that an investigational anticancer drug, elesclomol (ES), can deliver Cu to critical mitochondrial cuproenzymes and has the potential to be repurposed for the treatment of Cu deficiency disorders. Here, we sought to determine the specificity of ES and the ES-Cu complex in delivering Cu to cuproenzymes in different intracellular compartments. Using a combination of yeast genetics, subcellular fractionation, and inductively coupled plasma-mass spectrometry–based metal measurements, we showed that ES and ES-Cu treatment results in an increase in cellular and mitochondrial Fe content, along with the expected increase in Cu. Using yeast mutants of Cu and Fe transporters, we demonstrate that ES-based elevation in cellular Fe levels is independent of the major cellular Cu importer but is dependent on the Fe importer Ftr1 and its partner Fet3, a multicopper oxidase. As Fet3 is metalated in the Golgi lumen, we sought to uncover the mechanism by which Fet3 receives Cu from ES. Using yeast knockouts of genes involved in Cu delivery to Fet3, we determined that ES can bypass Atx1, a metallochaperone involved in Cu delivery to the Golgi membrane Cu pump, Ccc2, but not Ccc2 itself. Taken together, our study provides a mechanism by which ES distributes Cu in cells and impacts cellular and mitochondrial Fe homeostasis.

Metabolic Bone Disease of Prematurity.

Metabolic Bone Disease of Prematurity.

Menkes Disease: Clinical Presentation and Imaging Characteristics.

Menkes Disease: Clinical Presentation and Imaging Characteristics.

Oral Elesclomol Treatment Alleviates Copper Deficiency in Animal Models.

Copper (Cu) is an essential trace element for key biochemical reactions. Dietary or genetic copper deficiencies are associated with anemia, cardiomyopathy, and neurodegeneration. The essential requirement for copper in humans is illustrated by Menkes disease, a fatal neurodegenerative disorder of early childhood caused by mutations in the ATP7A copper transporter. Recent groundbreaking studies have demonstrated that a copper delivery small molecule compound, elesclomol (ES), is able to substantially ameliorate pathology and lethality in a mouse model of Menkes disease when injected as an ES-Cu2+ complex. It is well appreciated that drugs administered through oral means are more convenient with better efficacy than injection methods. Here we show, using genetic models of copper-deficient C. elegans and mice, that dietary ES supplementation fully rescues copper deficiency phenotypes. Worms lacking either the homolog of the CTR1 copper importer or the ATP7 copper exporter showed normal development when fed ES. Oral gavage with ES rescued intestine-specific Ctr1 knockout mice from early postnatal lethality without additional copper supplementation. Our findings reveal that ES facilitates copper delivery from dietary sources independent of the intestinal copper transporter CTR1 and provide insight into oral administration of ES as an optimal therapeutic for Menkes disease and possibly other disorders of copper insufficiency.

Identification of a Novel Deep Intronic Variant by Whole Genome Sequencing Combined With RNA Sequencing in a Chinese Patient With Menkes Disease

Background: Menkes disease (MD) is a rare X-linked connective tissue disorder of copper metabolism caused by pathogenic variant(s) in ATP7A gene. The aim of the present study is to determine the clinical characteristics and molecular basis of one patient with MD. Methods: One 10-month-old Chinese boy who met the clinical manifestations of MD was enrolled in this study. Whole genome sequencing (WGS) was performed in the patient in order to identify the variant(s), followed by Sanger sequencing. RNA sequencing (RNA-seq) from whole blood was subsequently applied to assess the effect of variant on transcription levels, and reverse transcriptase-polymerase chain reaction (RT-PCR) was performed for further validation. In addition, X chromosome inactivation (XCI) status of the patient’s mother at the DNA level was measured by capillary electrophoresis. Results: The patient suffered from intermittent convulsions for more than 6 months, with psychomoto retardation and neurodegenerations. The patient also had curly hair, hypopigmented skin, cutis laxa, decreased muscle strength and hypotonia. MRI showed the intracranial arteries were tortuous with some “spiral” changes. The patient’s serum ceruloplasmin level was low. WGS revealed one novel hemizygous variant, c.2627-501C > T (NM_000,052.7), located in the deep intronic sequence of ATP7A gene. Sanger sequencing confirmed that the variant was inherited from his mother. RNA-seq confirmed the variant itself, and identified a pseudo-exon inserted between exons 12 and 13 in mRNA of ATP7A. The sequencing results of RT-PCR from the patient confirmed this finding, while neither of his parents detected aberrant splicing. The Capillary electrophoresis results showed that the patient’s mother had a skewed XCI. Conclusion: Our finding of the variant enlarges the variant spectrum in the ATP7A gene. This is a novel deep intronic variant which leads to the activation of a pseudo-exons in the ATP7A gene, and it demonstrates the usefulness of WGS combined with RNA-seq, in terms of revealing disease-causing variants in non-coding regions. Furthermore, the fact that the deep intronic variants cause disease by the activation of pseudo-exon inclusion indicates that in MD this might be an important mechanism.

Critical Points in the Methodology of Preparing Copper (II) Histidinate Injections and their Quality Assessment Applying Color Measurement

Copper (II) histidinate injection solution, applied in Menkes disease treatment, is characterized by low stability due to sensitivity to oxidation. The aim of this article was to determine the critical points of the injection preparation procedure, taking into account selection of appropriate packaging, determining the solution pH or application of an excess of L-histidine. In order to assess the stability of the Cu(His)2 complex, the spectrophotometric method (VIS: 400-800 nm), and the colorimetric method using a reflectance colorimeter were applied. The color changes observed using the CIELAB color system made it possible to determine: the differences in the observed color (ΔΕ) and the color chroma (C*) and hue (h°). It was found that the following parameters: λmax and ΔE enable fast and objective assessment of copper (II) histidinate injection solution quality. The advantage of the colorimetric method is the non-invasiveness of the analysis which is performed through the packaging material (transparent vial). The developed methodology of preparing Cu(His)2 injections in hospitals or community pharmacies guarantees their stability for at least 6 months, provided that the solution is stored at lower temperatures (2–8°C or 4°C).

EP195: Safety and efficacy of Copper Histidinate (CUTX-101) treatment for Menkes disease caused by severe loss-of-function variants in ATP7A

Menkes disease (MD) is a X-linked recessive disorder caused by variants in the copper transporter gene, ATP7A. Although MD patients appear asymptomatic at birth, they develop significant neurological signs and symptoms such as seizures, hypotonia, and failure to thrive approximately 6-10 weeks after birth. Death by 3 years of age is the typical outcome in untreated MD. Copper histidinate (CUTX-101) is being investigated for treatment of this illness.