201
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Morishita H, Mizushima N. Autophagy in the lens. Exp Eye Res 2015; 144:22-8. [PMID: 26302409 DOI: 10.1016/j.exer.2015.08.019] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2015] [Revised: 07/30/2015] [Accepted: 08/18/2015] [Indexed: 10/23/2022]
Abstract
The lens of the eye is a transparent tissue composed of lens fiber cells that differentiate from lens epithelial cells and degrade all cytoplasmic organelles during terminal differentiation. Autophagy is a major intracellular degradation system in which cytoplasmic proteins and organelles are degraded in the lysosome. Although autophagy is constitutively activated in the lens and has been proposed to be involved in lens organelle degradation, its precise role is not well understood. Recent genetic studies in mice have demonstrated that autophagy is critically important for intracellular quality control in the lens but can be dispensable for lens organelle degradation. Here, we review recent findings on the roles of autophagy and lysosomes in organelle degradation and intracellular quality control in the lens, and discuss their possible involvement in the development of human cataract.
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Affiliation(s)
- Hideaki Morishita
- Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Noboru Mizushima
- Department of Biochemistry and Molecular Biology, Graduate School and Faculty of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan.
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202
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Disease-associated mutation in SRSF2 misregulates splicing by altering RNA-binding affinities. Proc Natl Acad Sci U S A 2015; 112:E4726-34. [PMID: 26261309 DOI: 10.1073/pnas.1514105112] [Citation(s) in RCA: 149] [Impact Index Per Article: 16.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Serine/arginine-rich splicing factor 2 (SRSF2) is an RNA-binding protein that plays important roles in splicing of mRNA precursors. SRSF2 mutations are frequently found in patients with myelodysplastic syndromes and certain leukemias, but how these mutations affect SRSF2 function has only begun to be examined. We used clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein-9 nuclease to introduce the P95H mutation to SRSF2 in K562 leukemia cells, generating an isogenic model so that splicing alterations can be attributed solely to mutant SRSF2. We found that SRSF2 (P95H) misregulates 548 splicing events (<1% of total). Of these events, 374 involved the inclusion of cassette exons, and the inclusion was either increased (206) or decreased (168). We detected a specific motif (UCCA/UG) enriched in the more-included exons and a distinct motif (UGGA/UG) in the more-excluded exons. RNA gel shift assays showed that a mutant SRSF2 derivative bound more tightly than its wild-type counterpart to RNA sites containing UCCAG but bound less tightly to UGGAG sites. Thus in most cases the pattern of exon inclusion or exclusion correlated with stronger or weaker RNA binding, respectively. We further show that the P95H mutation does not affect other functions of SRSF2, i.e., protein-protein interactions with key splicing factors. Our results thus demonstrate that the P95H mutation positively or negatively alters the binding affinity of SRSF2 for cognate RNA sites in target transcripts, leading to misregulation of exon inclusion. Our findings shed light on the mechanism of the disease-associated SRSF2 mutation in splicing regulation and also reveal a group of misspliced mRNA isoforms for potential therapeutic targeting.
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203
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Abidi A, Mignon-Ravix C, Cacciagli P, Girard N, Milh M, Villard L. Early-onset epileptic encephalopathy as the initial clinical presentation of WDR45 deletion in a male patient. Eur J Hum Genet 2015; 24:615-8. [PMID: 26173968 DOI: 10.1038/ejhg.2015.159] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2015] [Revised: 05/27/2015] [Accepted: 06/11/2015] [Indexed: 01/05/2023] Open
Abstract
Variants in the WD repeat 45 (WDR45) gene in human Xp11.23 have recently been identified in patients suffering from neurodegeneration with brain iron accumulation, a genetically and phenotypically heterogeneous condition. WDR45 variants cause a childhood-onset encephalopathy accompanied by neurodegeneration in adulthood and iron accumulation in the basal ganglia. They have been almost exclusively found in females, and male lethality was suggested. Here we describe a male patient suffering from a severe and early neurological phenotype, initially presenting early-onset epileptic spasms in clusters associated with an abnormal interictal electroencephalography showing slow background activity, large amplitude asynchronous spikes and abnormal neurological development. This patient is a carrier of a 19.9-kb microdeletion in Xp11.23 containing three genes, including WDR45. These findings reveal that males with WDR45 deletions are viable, and can present with early-onset epileptic encephalopathy without brain iron accumulation.
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Affiliation(s)
- Affef Abidi
- Inserm, UMR_S 910, Faculté de Médecine de La Timone, Marseille, France.,Aix Marseille Université, GMGF, Marseille, France
| | - Cécile Mignon-Ravix
- Inserm, UMR_S 910, Faculté de Médecine de La Timone, Marseille, France.,Aix Marseille Université, GMGF, Marseille, France
| | - Pierre Cacciagli
- Inserm, UMR_S 910, Faculté de Médecine de La Timone, Marseille, France.,Aix Marseille Université, GMGF, Marseille, France.,Département de Génétique Médicale, Hôpital d'Enfants de La Timone, Marseille, France
| | - Nadine Girard
- Département de Neuroradiologie, Hôpital d'Adultes de La Timone, Marseille, France
| | - Mathieu Milh
- Inserm, UMR_S 910, Faculté de Médecine de La Timone, Marseille, France.,Aix Marseille Université, GMGF, Marseille, France.,Service de Neurologie Pédiatrique, Hôpital d'Enfants de La Timone, Marseille, France
| | - Laurent Villard
- Inserm, UMR_S 910, Faculté de Médecine de La Timone, Marseille, France.,Aix Marseille Université, GMGF, Marseille, France
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204
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Dusek P, Litwin T, Czlonkowska A. Wilson disease and other neurodegenerations with metal accumulations. Neurol Clin 2015; 33:175-204. [PMID: 25432729 DOI: 10.1016/j.ncl.2014.09.006] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Trace elements, such as iron, copper, manganese, and calcium, which are essential constituents necessary for cellular homeostasis, become toxic when present in excess quantities. In this article, we describe disorders arising from endogenous dysregulation of metal homeostasis leading to their tissue accumulation. Although subgroups of these diseases lead to regional brain metal accumulation, mostly in globus pallidus, which is susceptible to accumulate divalent metal ions, other subgroups cause systemic metal accumulation affecting the whole brain, liver, and other parenchymal organs. The latter group comprises Wilson disease, manganese transporter deficiency, and aceruloplasminemia and responds favorably to chelation treatment.
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Affiliation(s)
- Petr Dusek
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine and General University Hospital in Prague, Charles University in Prague, Kateřinská 30, Prague 128 21, Czech Republic; Institute of Neuroradiology, University Medicine Goettingen, Robert-Koch-Street 40, Göttingen 37075, Germany.
| | - Tomasz Litwin
- 2nd Department of Neurology, Institute Psychiatry and Neurology, Sobieskiego 9, Warsaw 02-957, Poland
| | - Anna Czlonkowska
- 2nd Department of Neurology, Institute Psychiatry and Neurology, Sobieskiego 9, Warsaw 02-957, Poland; Department of Experimental and Clinical Pharmacology, Medical University, Banacha 1b, Warsaw 02-097, Poland
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205
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Abstract
Autophagy is a conserved catabolic process that degrades cytoplasmic constituents and organelles in the lysosome. Starvation-induced protein degradation is a salient feature of autophagy but recent progress has illuminated how autophagy, during both starvation and nutrient-replete conditions, can mobilize diverse cellular energy and nutrient stores such as lipids, carbohydrates and iron. Processes such as lipophagy, glycophagy and ferritinophagy enable cells to salvage key metabolites to sustain and facilitate core anabolic functions. Here, we discuss the established and emerging roles of autophagy in fuelling biosynthetic capacity and in promoting metabolic and nutrient homeostasis.
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206
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Haack T, Staufner C, Köpke M, Straub B, Kölker S, Thiel C, Freisinger P, Baric I, McKiernan P, Dikow N, Harting I, Beisse F, Burgard P, Kotzaeridou U, Kühr J, Himbert U, Taylor R, Distelmaier F, Vockley J, Ghaloul-Gonzalez L, Zschocke J, Kremer L, Graf E, Schwarzmayr T, Bader D, Gagneur J, Wieland T, Terrile C, Strom T, Meitinger T, Hoffmann G, Prokisch H. Biallelic Mutations in NBAS Cause Recurrent Acute Liver Failure with Onset in Infancy. Am J Hum Genet 2015; 97:163-9. [PMID: 26073778 PMCID: PMC4572578 DOI: 10.1016/j.ajhg.2015.05.009] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2015] [Accepted: 05/11/2015] [Indexed: 11/24/2022] Open
Abstract
Acute liver failure (ALF) in infancy and childhood is a life-threatening emergency. Few conditions are known to cause recurrent acute liver failure (RALF), and in about 50% of cases, the underlying molecular cause remains unresolved. Exome sequencing in five unrelated individuals with fever-dependent RALF revealed biallelic mutations in NBAS. Subsequent Sanger sequencing of NBAS in 15 additional unrelated individuals with RALF or ALF identified compound heterozygous mutations in an additional six individuals from five families. Immunoblot analysis of mutant fibroblasts showed reduced protein levels of NBAS and its proposed interaction partner p31, both involved in retrograde transport between endoplasmic reticulum and Golgi. We recommend NBAS analysis in individuals with acute infantile liver failure, especially if triggered by fever.
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207
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Paudel R, Li A, Wiethoff S, Bandopadhyay R, Bhatia K, de Silva R, Houlden H, Holton JL. Neuropathology of Beta-propeller protein associated neurodegeneration (BPAN): a new tauopathy. Acta Neuropathol Commun 2015; 3:39. [PMID: 26123052 PMCID: PMC4486689 DOI: 10.1186/s40478-015-0221-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 06/19/2015] [Indexed: 11/27/2022] Open
Abstract
Introduction Beta-propeller protein associated neurodegeneration (BPAN) is associated with mutations in the WD repeat domain 45 (WDR45) gene on chromosome Xp11 resulting in reduced autophagic flux. This study describes the clinical and neuropathological features of a female 51 year old BPAN case. The clinical history includes learning disability and progressive gait abnormalities since childhood followed by progressive dystonic features in young adulthood. Brain imaging revealed generalised brain atrophy and bilateral mineralisation of the globus pallidus and substantia nigra. Results The major pathological findings were observed in the substantia nigra with excess iron deposition, gliosis, axonal swellings and severe neuronal loss. Iron deposition was also observed in the globus pallidus. There was extensive hyperphosphorylated-tau deposition in the form of neurofibrillary tangles, pre-tangles and neuropil threads. Furthermore, histological studies and immunoblotting confirmed a mixed Alzheimer type 3-and 4-repeat tau pathology. Microtubule-associated protein 1A/1B-light chain 3 (LC3) immunoblotting of brain homogenates indicated autophagic activity and may support the role of WDR45 in autophagy. Conclusions The widespread Alzheimer-type tau pathology in this disease indicates that this should be considered as a tauopathy and adds further support to the proposal that impaired autophagy may have a role in tauopathies. Electronic supplementary material The online version of this article (doi:10.1186/s40478-015-0221-3) contains supplementary material, which is available to authorized users.
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208
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Khalifa M, Naffaa L. Exome sequencing reveals a novel WDR45 frameshift mutation and inherited POLR3A heterozygous variants in a female with a complex phenotype and mixed brain MRI findings. Eur J Med Genet 2015; 58:381-6. [PMID: 26096995 DOI: 10.1016/j.ejmg.2015.05.009] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 05/26/2015] [Indexed: 11/27/2022]
Abstract
WDR45 and POLR3A are newly recognized genes; each is associated with a distinct neurodegenerative disease. WDR45 is an X-linked gene associated with a dominant form of Neurodegeneration with Brain Iron Accumulation (NBIA), manifested by progressive disabilities, dystonia, cognitive decline, spastic paraplegia, neuropsychiatric abnormalities and iron deposition in the basal ganglia on brain imaging. POLR3A, on the other hand, is an autosomal gene, and its mutations cause a recessive form of a hypomyelination with leukodystrophy disease, also known as 4H syndrome, characterized by congenital Hypomyelination with thinning of the corpus callosum, Hypodontia and Hypogonadotropic Hypogonadism. We report on a female child with severe intellectual disability, aphasia, short stature, ataxia, failure to thrive and structural brain abnormalities. Brain MRI obtained in late infancy showed hypomyelination involving the central periventricular white matter and thinning of the corpus callosum with no evidence of iron accumulation. Brain MRI obtained in childhood showed stable hypomyelination, with progressive iron accumulation in the basal ganglia, in particular in the globus pallidus and substantia nigra. Whole Exome Sequencing (WES) identified a novel WDR45 frameshift deleterious mutation in Exon 9 (c.587-588del) and also revealed three POLR3A missense heterozygous variants. The first is a maternally inherited novel missense variant in exon 4 (c.346A > G). Exon 13 carried two heterozygous missense variants, a maternally inherited variant (c.1724A > T) and a paternally inherited variant (1745G > A). These variants are considered likely damaging. The patient's complex clinical phenotype and mixed brain MRI findings might be attributed to the confounding effects of the expression of these two mutant genes.
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Affiliation(s)
- Mohamed Khalifa
- Department of Medical Genetics and Genomics, Akron Children's Hospital, Akron, OH, USA.
| | - Lena Naffaa
- Department Radiology, Akron Children's Hospital, Akron, OH, USA
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209
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Jinks RN, Puffenberger EG, Baple E, Harding B, Crino P, Fogo AB, Wenger O, Xin B, Koehler AE, McGlincy MH, Provencher MM, Smith JD, Tran L, Al Turki S, Chioza BA, Cross H, Harlalka GV, Hurles ME, Maroofian R, Heaps AD, Morton MC, Stempak L, Hildebrandt F, Sadowski CE, Zaritsky J, Campellone K, Morton DH, Wang H, Crosby A, Strauss KA. Recessive nephrocerebellar syndrome on the Galloway-Mowat syndrome spectrum is caused by homozygous protein-truncating mutations of WDR73. Brain 2015; 138:2173-90. [PMID: 26070982 PMCID: PMC4511861 DOI: 10.1093/brain/awv153] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 04/14/2015] [Indexed: 12/20/2022] Open
Abstract
Galloway-Mowat syndrome (GMS) is a neurodevelopmental disorder characterized by microcephaly, cerebellar hypoplasia, nephrosis, and profound intellectual disability. Jinks et al. extend the GMS spectrum by identifying a novel nephrocerebellar syndrome with selective striatal cholinergic interneuron loss and complete lateral geniculate nucleus delamination, caused by a frameshift mutation in WDR73. We describe a novel nephrocerebellar syndrome on the Galloway-Mowat syndrome spectrum among 30 children (ages 1.0 to 28 years) from diverse Amish demes. Children with nephrocerebellar syndrome had progressive microcephaly, visual impairment, stagnant psychomotor development, abnormal extrapyramidal movements and nephrosis. Fourteen died between ages 2.7 and 28 years, typically from renal failure. Post-mortem studies revealed (i) micrencephaly without polymicrogyria or heterotopia; (ii) atrophic cerebellar hemispheres with stunted folia, profound granule cell depletion, Bergmann gliosis, and signs of Purkinje cell deafferentation; (iii) selective striatal cholinergic interneuron loss; and (iv) optic atrophy with delamination of the lateral geniculate nuclei. Renal tissue showed focal and segmental glomerulosclerosis and extensive effacement and microvillus transformation of podocyte foot processes. Nephrocerebellar syndrome mapped to 700 kb on chromosome 15, which contained a single novel homozygous frameshift variant (WDR73 c.888delT; p.Phe296Leufs*26). WDR73 protein is expressed in human cerebral cortex, hippocampus, and cultured embryonic kidney cells. It is concentrated at mitotic microtubules and interacts with α-, β-, and γ-tubulin, heat shock proteins 70 and 90 (HSP-70; HSP-90), and the carbamoyl phosphate synthetase 2/aspartate transcarbamylase/dihydroorotase multi-enzyme complex. Recombinant WDR73 p.Phe296Leufs*26 and p.Arg256Profs*18 proteins are truncated, unstable, and show increased interaction with α- and β-tubulin and HSP-70/HSP-90. Fibroblasts from patients homozygous for WDR73 p.Phe296Leufs*26 proliferate poorly in primary culture and senesce early. Our data suggest that in humans, WDR73 interacts with mitotic microtubules to regulate cell cycle progression, proliferation and survival in brain and kidney. We extend the Galloway-Mowat syndrome spectrum with the first description of diencephalic and striatal neuropathology.
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Affiliation(s)
- Robert N Jinks
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Erik G Puffenberger
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA 2 Clinic for Special Children, Strasburg, PA 17579, USA
| | - Emma Baple
- 3 RILD Wellcome Wolfson Centre, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK 4 Human Genetics and Genomic Medicine, Faculty of Medicine, University of Southampton, UK 5 Wessex Clinical Genetics Service, Princess Anne Hospital, Southampton, UK
| | - Brian Harding
- 6 Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia and Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Peter Crino
- 7 Shriners Hospital Paediatric Research Centre, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Agnes B Fogo
- 8 Division of Renal Pathology, Vanderbilt University School of Medicine, Nashville, TN 37232, USA
| | - Olivia Wenger
- 9 New Leaf Clinic for Special Children, Mount Eaton, OH 44659, USA 10 Department of Paediatrics, Akron Children's Hospital, Akron, OH 44302, USA
| | - Baozhong Xin
- 11 DDC Clinic for Special Needs Children, Middlefield, OH 44062, USA
| | - Alanna E Koehler
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Madeleine H McGlincy
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Margaret M Provencher
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Jeffrey D Smith
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Linh Tran
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA
| | - Saeed Al Turki
- 12 Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Barry A Chioza
- 13 Medical Research, RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter EX1 2LU, UK
| | - Harold Cross
- 14 Department of Ophthalmology, University of Arizona College of Medicine, Tucson, AZ 85711, USA
| | - Gaurav V Harlalka
- 13 Medical Research, RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter EX1 2LU, UK
| | - Matthew E Hurles
- 12 Wellcome Trust Sanger Institute, Hinxton, Cambridge CB10 1SA, UK
| | - Reza Maroofian
- 13 Medical Research, RILD Wellcome Wolfson Centre, University of Exeter Medical School, Exeter EX1 2LU, UK
| | - Adam D Heaps
- 2 Clinic for Special Children, Strasburg, PA 17579, USA
| | - Mary C Morton
- 2 Clinic for Special Children, Strasburg, PA 17579, USA
| | - Lisa Stempak
- 15 Department of Pathology, University Hospitals Case Medical Centre, Cleveland, OH 44106, USA 16 Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA
| | - Friedhelm Hildebrandt
- 17 Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA 18 Division of Nephrology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Carolin E Sadowski
- 18 Division of Nephrology, Department of Medicine, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Joshua Zaritsky
- 19 Department of Paediatrics, Nemours/Alfred I. DuPont Hospital for Children, Wilmington, DE 19803, USA
| | - Kenneth Campellone
- 20 Department of Molecular and Cell Biology and Institute for Systems Genomics, University of Connecticut, Storrs, CT 06269, USA
| | - D Holmes Morton
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA 2 Clinic for Special Children, Strasburg, PA 17579, USA 21 Lancaster General Hospital, Lancaster, PA 17602, USA
| | - Heng Wang
- 11 DDC Clinic for Special Needs Children, Middlefield, OH 44062, USA 22 Department of Paediatrics, Rainbow Babies and Children's Hospital and Department of Molecular Cardiology, Cleveland Clinic, Cleveland, OH 44195, USA
| | - Andrew Crosby
- 3 RILD Wellcome Wolfson Centre, Royal Devon and Exeter NHS Foundation Trust, Barrack Road, Exeter, EX2 5DW, UK
| | - Kevin A Strauss
- 1 Department of Biology and Biological Foundations of Behaviour Program, Franklin and Marshall College, Lancaster, PA 17604, USA 2 Clinic for Special Children, Strasburg, PA 17579, USA 21 Lancaster General Hospital, Lancaster, PA 17602, USA
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210
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Ryu SW, Kim JS, Lee SH. Beta-Propeller-Protein-Associated Neurodegeneration: A Case of Mutation in WDR45. J Clin Neurol 2015; 11:289-91. [PMID: 26022463 PMCID: PMC4507387 DOI: 10.3988/jcn.2015.11.3.289] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 02/17/2015] [Accepted: 02/17/2015] [Indexed: 11/17/2022] Open
Affiliation(s)
- Sook Won Ryu
- Department of Laboratory Medicine, Kangwon National University School of Medicine, Chuncheon, Korea
| | - Jang Su Kim
- Department of Laboratory Medicine, S-Jungang Hospital, Jeju, Korea
| | - Seung Hwan Lee
- Department of Neurology, Kangwon National University School of Medicine, Chuncheon, Korea.
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211
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Grimmel M, Backhaus C, Proikas-Cezanne T. WIPI-Mediated Autophagy and Longevity. Cells 2015; 4:202-17. [PMID: 26010754 PMCID: PMC4493456 DOI: 10.3390/cells4020202] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Revised: 05/17/2015] [Accepted: 05/17/2015] [Indexed: 01/20/2023] Open
Abstract
Autophagy is a lysosomal degradation process for cytoplasmic components, including organelles, membranes, and proteins, and critically secures eukaryotic cellular homeostasis and survival. Moreover, autophagy-related (ATG) genes are considered essential for longevity control in model organisms. Central to the regulatory relationship between autophagy and longevity is the control of insulin/insulin-like growth factor receptor-driven activation of mTOR (mechanistic target of rapamycin), which inhibits WIPI (WD repeat protein interacting with phosphoinositides)-mediated autophagosome formation. Release of the inhibitory mTOR action on autophagy permits the production of PI3P (phosphatidylinositol-3 phosphate), predominantly at the endoplasmic reticulum, to function as an initiation signal for the formation of autophagosomes. WIPI proteins detect this pool of newly produced PI3P and function as essential PI3P effector proteins that recruit downstream autophagy-related (ATG) proteins. The important role of WIPI proteins in autophagy is highlighted by functional knockout of the WIPI homologues ATG-18 and EPG-6 in Caenorhabditis elegans (C. elegans). Adult lifespan is significantly reduced in ATG-18 mutant animals, demonstrating that longevity as such is crucially determined by essential autophagy factors. In this review we summarize the role of WIPI proteins and their C. elegans homologues with regard to the molecular basis of aging. As the development of strategies on how to increase health span in humans is increasingly appreciated, we speculate that targeting WIPI protein function might represent a therapeutic opportunity to fight and delay the onset of age-related human diseases.
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Affiliation(s)
- Mona Grimmel
- Autophagy Laboratory, Department of Molecular Biology, Interfaculty Institute of Cell Biology, Faculty of Science, Eberhard Karls University Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Charlotte Backhaus
- Autophagy Laboratory, Department of Molecular Biology, Interfaculty Institute of Cell Biology, Faculty of Science, Eberhard Karls University Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Tassula Proikas-Cezanne
- Autophagy Laboratory, Department of Molecular Biology, Interfaculty Institute of Cell Biology, Faculty of Science, Eberhard Karls University Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany.
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212
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Meyer E, Kurian MA, Hayflick SJ. Neurodegeneration with Brain Iron Accumulation: Genetic Diversity and Pathophysiological Mechanisms. Annu Rev Genomics Hum Genet 2015; 16:257-79. [PMID: 25973518 DOI: 10.1146/annurev-genom-090314-025011] [Citation(s) in RCA: 68] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Neurodegeneration with brain iron accumulation (NBIA) comprises a heterogeneous group of progressive disorders with the common feature of excessive iron deposition in the brain. Over the last decade, advances in sequencing technologies have greatly facilitated rapid gene discovery, and several single-gene disorders are now included in this group. Identification of the genetic bases of the NBIA disorders has advanced our understanding of the disease processes caused by reduced coenzyme A synthesis, impaired lipid metabolism, mitochondrial dysfunction, and defective autophagy. The contribution of iron to disease pathophysiology remains uncertain, as does the identity of a putative final common pathway by which the iron accumulates. Ongoing elucidation of the pathogenesis of each NBIA disorder will have significant implications for the identification and design of novel therapies to treat patients with these disorders.
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Affiliation(s)
- Esther Meyer
- Molecular Neurosciences, Developmental Neurosciences Programme, Institute of Child Health, University College London, London WC1N 1EH, United Kingdom; ,
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213
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High frequency of beta-propeller protein-associated neurodegeneration (BPAN) among patients with intellectual disability and young-onset parkinsonism. Neurobiol Aging 2015; 36:2004.e9-2004.e15. [DOI: 10.1016/j.neurobiolaging.2015.01.020] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 01/22/2015] [Accepted: 01/24/2015] [Indexed: 11/15/2022]
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214
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Rurangwa E, Sipkema D, Kals J, Ter Veld M, Forlenza M, Bacanu GM, Smidt H, Palstra AP. Impact of a novel protein meal on the gastrointestinal microbiota and the host transcriptome of larval zebrafish Danio rerio. Front Physiol 2015; 6:133. [PMID: 25983694 PMCID: PMC4415425 DOI: 10.3389/fphys.2015.00133] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 04/14/2015] [Indexed: 01/06/2023] Open
Abstract
Larval zebrafish was subjected to a methodological exploration of the gastrointestinal microbiota and transcriptome. Assessed was the impact of two dietary inclusion levels of a novel protein meal (NPM) of animal origin (ragworm Nereis virens) on the gastrointestinal tract (GIT). Microbial development was assessed over the first 21 days post egg fertilization (dpf) through 16S rRNA gene-based microbial composition profiling by pyrosequencing. Differentially expressed genes in the GIT were demonstrated at 21 dpf by whole transcriptome sequencing (mRNAseq). Larval zebrafish showed rapid temporal changes in microbial colonization but domination occurred by one to three bacterial species generally belonging to Proteobacteria and Firmicutes. The high iron content of NPM may have led to an increased relative abundance of bacteria that were related to potential pathogens and bacteria with an increased iron metabolism. Functional classification of the 328 differentially expressed genes indicated that the GIT of larvae fed at higher NPM level was more active in transmembrane ion transport and protein synthesis. mRNAseq analysis did not reveal a major activation of genes involved in the immune response or indicating differences in iron uptake and homeostasis in zebrafish fed at the high inclusion level of NPM.
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Affiliation(s)
- Eugene Rurangwa
- Institute for Marine Resources and Ecosystem Studies, Wageningen University and Research Centre Yerseke, Netherlands
| | - Detmer Sipkema
- Laboratory of Microbiology, Wageningen University Wageningen, Netherlands
| | - Jeroen Kals
- Institute for Marine Resources and Ecosystem Studies, Wageningen University and Research Centre Yerseke, Netherlands
| | - Menno Ter Veld
- Aquaculture and Fisheries Group, Wageningen University Wageningen, Netherlands
| | - Maria Forlenza
- Cell Biology and Immunology Group, Wageningen University Wageningen, Netherlands
| | - Gianina M Bacanu
- Laboratory of Microbiology, Wageningen University Wageningen, Netherlands
| | - Hauke Smidt
- Laboratory of Microbiology, Wageningen University Wageningen, Netherlands
| | - Arjan P Palstra
- Institute for Marine Resources and Ecosystem Studies, Wageningen University and Research Centre Yerseke, Netherlands
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Zhang H, Baehrecke EH. Eaten alive: novel insights into autophagy from multicellular model systems. Trends Cell Biol 2015; 25:376-87. [PMID: 25862458 DOI: 10.1016/j.tcb.2015.03.001] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2014] [Revised: 02/12/2015] [Accepted: 03/11/2015] [Indexed: 11/29/2022]
Abstract
Autophagy delivers cytoplasmic material to lysosomes for degradation. First identified in yeast, the core genes that control this process are conserved in higher organisms. Studies of mammalian cell cultures have expanded our understanding of the core autophagy pathway, but cannot reveal the unique animal-specific mechanisms for the regulation and function of autophagy. Multicellular organisms have different types of cells that possess distinct composition, morphology, and organization of intracellular organelles. In addition, the autophagic machinery integrates signals from other cells and environmental conditions to maintain cell, tissue and organism homeostasis. Here, we highlight how studies of autophagy in flies and worms have identified novel core autophagy genes and mechanisms, and provided insight into the context-specific regulation and function of autophagy.
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Affiliation(s)
- Hong Zhang
- Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Eric H Baehrecke
- Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Medical School, Worcester, MA 01605, USA.
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216
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Schneider SA, Kurian MA. What the future holds for the genetic diagnosis for neurodegeneration with brain iron accumulation syndromes? Expert Opin Orphan Drugs 2015. [DOI: 10.1517/21678707.2015.1016910] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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217
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Uchino S, Saitsu H, Kumada S, Nakata Y, Matsumoto N. Stereotypic Hand Movements in β-Propeller Protein-Associated Neurodegeneration: First Video Report. Mov Disord Clin Pract 2015; 2:190-191. [PMID: 30713893 DOI: 10.1002/mdc3.12158] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2014] [Revised: 11/16/2014] [Accepted: 11/21/2014] [Indexed: 11/08/2022] Open
Affiliation(s)
- Shumpei Uchino
- Department of Neuropediatrics Tokyo Metropolitan Neurological Hospital Tokyo Japan
| | - Hirotomo Saitsu
- Department of Human Genetics Graduate School of Medicine Yokohama City University Yokohama Japan
| | - Satoko Kumada
- Department of Neuropediatrics Tokyo Metropolitan Neurological Hospital Tokyo Japan
| | - Yasuhiro Nakata
- Department of Neuroradiology Tokyo Metropolitan Neurological Hospital Tokyo Japan
| | - Naomichi Matsumoto
- Department of Human Genetics Graduate School of Medicine Yokohama City University Yokohama Japan
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Haack TB, Jackson CB, Murayama K, Kremer LS, Schaller A, Kotzaeridou U, de Vries MC, Schottmann G, Santra S, Büchner B, Wieland T, Graf E, Freisinger P, Eggimann S, Ohtake A, Okazaki Y, Kohda M, Kishita Y, Tokuzawa Y, Sauer S, Memari Y, Kolb-Kokocinski A, Durbin R, Hasselmann O, Cremer K, Albrecht B, Wieczorek D, Engels H, Hahn D, Zink AM, Alston CL, Taylor RW, Rodenburg RJ, Trollmann R, Sperl W, Strom TM, Hoffmann GF, Mayr JA, Meitinger T, Bolognini R, Schuelke M, Nuoffer JM, Kölker S, Prokisch H, Klopstock T. Deficiency of ECHS1 causes mitochondrial encephalopathy with cardiac involvement. Ann Clin Transl Neurol 2015; 2:492-509. [PMID: 26000322 PMCID: PMC4435704 DOI: 10.1002/acn3.189] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 02/03/2015] [Indexed: 01/01/2023] Open
Abstract
Objective Short-chain enoyl-CoA hydratase (ECHS1) is a multifunctional mitochondrial matrix enzyme that is involved in the oxidation of fatty acids and essential amino acids such as valine. Here, we describe the broad phenotypic spectrum and pathobiochemistry of individuals with autosomal-recessive ECHS1 deficiency. Methods Using exome sequencing, we identified ten unrelated individuals carrying compound heterozygous or homozygous mutations in ECHS1. Functional investigations in patient-derived fibroblast cell lines included immunoblotting, enzyme activity measurement, and a palmitate loading assay. Results Patients showed a heterogeneous phenotype with disease onset in the first year of life and course ranging from neonatal death to survival into adulthood. The most prominent clinical features were encephalopathy (10/10), deafness (9/9), epilepsy (6/9), optic atrophy (6/10), and cardiomyopathy (4/10). Serum lactate was elevated and brain magnetic resonance imaging showed white matter changes or a Leigh-like pattern resembling disorders of mitochondrial energy metabolism. Analysis of patients’ fibroblast cell lines (6/10) provided further evidence for the pathogenicity of the respective mutations by showing reduced ECHS1 protein levels and reduced 2-enoyl-CoA hydratase activity. While serum acylcarnitine profiles were largely normal, in vitro palmitate loading of patient fibroblasts revealed increased butyrylcarnitine, unmasking the functional defect in mitochondrial β-oxidation of short-chain fatty acids. Urinary excretion of 2-methyl-2,3-dihydroxybutyrate – a potential derivative of acryloyl-CoA in the valine catabolic pathway – was significantly increased, indicating impaired valine oxidation. Interpretation In conclusion, we define the phenotypic spectrum of a new syndrome caused by ECHS1 deficiency. We speculate that both the β-oxidation defect and the block in l-valine metabolism, with accumulation of toxic methacrylyl-CoA and acryloyl-CoA, contribute to the disorder that may be amenable to metabolic treatment approaches.
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Affiliation(s)
- Tobias B Haack
- Institute of Human Genetics, Technische Universität München 81675, Munich, Germany ; Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health 85764, Neuherberg, Germany
| | - Christopher B Jackson
- Institute of Clinical Chemistry and University Children's Hospital, University of Bern 3010, Bern, Switzerland
| | - Kei Murayama
- Department of Metabolism, Chiba Children's Hospital Chiba, 266-0007, Japan
| | - Laura S Kremer
- Institute of Human Genetics, Technische Universität München 81675, Munich, Germany ; Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health 85764, Neuherberg, Germany
| | - André Schaller
- Division of Human Genetics, Department of Pediatrics, University of Bern 3010, Bern, Switzerland
| | - Urania Kotzaeridou
- Divisions of Inherited Metabolic Disease and Neuropediatrics, Department of General Pediatrics, University Hospital Heidelberg D-69120, Heidelberg, Germany
| | - Maaike C de Vries
- Department of Pediatrics, Nijmegen Center for Mitochondrial Disorders, Radboud University Center 6525 GA, Nijmegen, The Netherlands
| | - Gudrun Schottmann
- Department of Neuropediatrics and NeuroCure Clinical Research Center, Charité Universitätsmedizin Berlin 13353, Berlin, Germany
| | - Saikat Santra
- Department of Pediatrics, Birmingham Children's Hospital Birmingham, B4 6NH, United Kingdom
| | - Boriana Büchner
- Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University 80336, Munich, Germany
| | - Thomas Wieland
- Institute of Human Genetics, Technische Universität München 81675, Munich, Germany ; Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health 85764, Neuherberg, Germany
| | - Elisabeth Graf
- Institute of Human Genetics, Technische Universität München 81675, Munich, Germany ; Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health 85764, Neuherberg, Germany
| | - Peter Freisinger
- Department of Pediatrics, Klinikum Reutlingen 72764, Reutlingen, Germany
| | - Sandra Eggimann
- Institute of Clinical Chemistry and University Children's Hospital, University of Bern 3010, Bern, Switzerland
| | - Akira Ohtake
- Department of Pediatrics, Faculty of Medicine, Saitama Medical University Saitama, 350-0495, Japan
| | - Yasushi Okazaki
- Division of Translational Research, Research Center for Genomic Medicine, Saitama Medical University Saitama, 350-1241, Japan ; Division of Functional Genomics & Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University Saitama, 350-1241, Japan
| | - Masakazu Kohda
- Division of Translational Research, Research Center for Genomic Medicine, Saitama Medical University Saitama, 350-1241, Japan
| | - Yoshihito Kishita
- Division of Functional Genomics & Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University Saitama, 350-1241, Japan
| | - Yoshimi Tokuzawa
- Division of Functional Genomics & Systems Medicine, Research Center for Genomic Medicine, Saitama Medical University Saitama, 350-1241, Japan
| | - Sascha Sauer
- Max-Planck-Institute for Molecular Genetics, Otto-Warburg Laboratory 14195, Berlin, Germany
| | - Yasin Memari
- Wellcome Trust Sanger Institute Hinxton, Cambridge, CB10 1SA, United Kingdom
| | | | - Richard Durbin
- Wellcome Trust Sanger Institute Hinxton, Cambridge, CB10 1SA, United Kingdom
| | - Oswald Hasselmann
- Department of Neuropediatrics, Children's Hospital of Eastern Switzerland St.Gallen 9006, St. Gallen, Switzerland
| | - Kirsten Cremer
- Institute of Human Genetics, University of Bonn 53127, Bonn, Germany
| | - Beate Albrecht
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen 45122, Essen, Germany
| | - Dagmar Wieczorek
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen 45122, Essen, Germany
| | - Hartmut Engels
- Institute of Human Genetics, University of Bonn 53127, Bonn, Germany
| | - Dagmar Hahn
- Institute of Clinical Chemistry and University Children's Hospital, University of Bern 3010, Bern, Switzerland
| | - Alexander M Zink
- Institute of Human Genetics, University of Bonn 53127, Bonn, Germany
| | - Charlotte L Alston
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Robert W Taylor
- Wellcome Trust Centre for Mitochondrial Research, Institute of Neuroscience, The Medical School, Newcastle University Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Richard J Rodenburg
- Department of Pediatrics, Nijmegen Center for Mitochondrial Disorders, Radboud University Center 6525 GA, Nijmegen, The Netherlands
| | - Regina Trollmann
- Department of Pediatrics, Friedrich-Alexander-University of Erlangen-Nürnberg 91054, Erlangen, Germany
| | - Wolfgang Sperl
- Department of Pediatrics, Paracelsus Medical University Salzburg 5020, Salzburg, Austria
| | - Tim M Strom
- Institute of Human Genetics, Technische Universität München 81675, Munich, Germany ; Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health 85764, Neuherberg, Germany
| | - Georg F Hoffmann
- Divisions of Inherited Metabolic Disease and Neuropediatrics, Department of General Pediatrics, University Hospital Heidelberg D-69120, Heidelberg, Germany
| | - Johannes A Mayr
- Department of Pediatrics, Paracelsus Medical University Salzburg 5020, Salzburg, Austria
| | - Thomas Meitinger
- Institute of Human Genetics, Technische Universität München 81675, Munich, Germany ; Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health 85764, Neuherberg, Germany ; Munich Cluster for Systems Neurology (SyNergy) 80336, Munich, Germany ; DZNE - German Center for Neurodegenerative Diseases 80336, Munich, Germany
| | - Ramona Bolognini
- Division of Human Genetics, Department of Pediatrics, University of Bern 3010, Bern, Switzerland
| | - Markus Schuelke
- Department of Neuropediatrics and NeuroCure Clinical Research Center, Charité Universitätsmedizin Berlin 13353, Berlin, Germany
| | - Jean-Marc Nuoffer
- Institute of Clinical Chemistry and University Children's Hospital, University of Bern 3010, Bern, Switzerland
| | - Stefan Kölker
- Divisions of Inherited Metabolic Disease and Neuropediatrics, Department of General Pediatrics, University Hospital Heidelberg D-69120, Heidelberg, Germany
| | - Holger Prokisch
- Institute of Human Genetics, Technische Universität München 81675, Munich, Germany ; Institute of Human Genetics, Helmholtz Zentrum München, German Research Center for Environmental Health 85764, Neuherberg, Germany
| | - Thomas Klopstock
- Department of Neurology, Friedrich-Baur-Institute, Ludwig-Maximilians-University 80336, Munich, Germany ; Munich Cluster for Systems Neurology (SyNergy) 80336, Munich, Germany ; DZNE - German Center for Neurodegenerative Diseases 80336, Munich, Germany
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Tzschach A, Grasshoff U, Beck-Woedl S, Dufke C, Bauer C, Kehrer M, Evers C, Moog U, Oehl-Jaschkowitz B, Di Donato N, Maiwald R, Jung C, Kuechler A, Schulz S, Meinecke P, Spranger S, Kohlhase J, Seidel J, Reif S, Rieger M, Riess A, Sturm M, Bickmann J, Schroeder C, Dufke A, Riess O, Bauer P. Next-generation sequencing in X-linked intellectual disability. Eur J Hum Genet 2015; 23:1513-8. [PMID: 25649377 DOI: 10.1038/ejhg.2015.5] [Citation(s) in RCA: 99] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Revised: 01/02/2014] [Accepted: 01/07/2015] [Indexed: 12/11/2022] Open
Abstract
X-linked intellectual disability (XLID) is a genetically heterogeneous disorder with more than 100 genes known to date. Most genes are responsible for a small proportion of patients only, which has hitherto hampered the systematic screening of large patient cohorts. We performed targeted enrichment and next-generation sequencing of 107 XLID genes in a cohort of 150 male patients. Hundred patients had sporadic intellectual disability, and 50 patients had a family history suggestive of XLID. We also analysed a sporadic female patient with severe ID and epilepsy because she had strongly skewed X-inactivation. Target enrichment and high parallel sequencing allowed a diagnostic coverage of >10 reads for ~96% of all coding bases of the XLID genes at a mean coverage of 124 reads. We found 18 pathogenic variants in 13 XLID genes (AP1S2, ATRX, CUL4B, DLG3, IQSEC2, KDM5C, MED12, OPHN1, SLC9A6, SMC1A, UBE2A, UPF3B and ZDHHC9) among the 150 male patients. Thirteen pathogenic variants were present in the group of 50 familial patients (26%), and 5 pathogenic variants among the 100 sporadic patients (5%). Systematic gene dosage analysis for low coverage exons detected one pathogenic hemizygous deletion. An IQSEC2 nonsense variant was detected in the female ID patient, providing further evidence for a role of this gene in encephalopathy in females. Skewed X-inactivation was more frequently observed in mothers with pathogenic variants compared with those without known X-linked defects. The mutation rate in the cohort of sporadic patients corroborates previous estimates of 5-10% for X-chromosomal defects in male ID patients.
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Affiliation(s)
- Andreas Tzschach
- Institute of Clinical Genetics, Technische Universität Dresden, Dresden, Germany.,Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Ute Grasshoff
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Stefanie Beck-Woedl
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Claudia Dufke
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Claudia Bauer
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Martin Kehrer
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Christina Evers
- Institute of Human Genetics, University of Heidelberg, Heidelberg, Germany
| | - Ute Moog
- Institute of Human Genetics, University of Heidelberg, Heidelberg, Germany
| | | | - Nataliya Di Donato
- Institute of Clinical Genetics, Technische Universität Dresden, Dresden, Germany
| | | | | | - Alma Kuechler
- Institute of Human Genetics, University Hospital Essen, Essen, Germany
| | - Solveig Schulz
- Center of Human Genetics, Jena University Hospital, Jena, Germany
| | - Peter Meinecke
- Institute of Human Genetics, University Hospital Hamburg-Eppendorf, Hamburg, Germany
| | | | | | | | - Silke Reif
- Practice of Medical Genetics, Dresden, Germany
| | | | - Angelika Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Marc Sturm
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Julia Bickmann
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Christopher Schroeder
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Andreas Dufke
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Olaf Riess
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
| | - Peter Bauer
- Institute of Medical Genetics and Applied Genomics, University of Tübingen, Tübingen, Germany
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220
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Tschentscher A, Dekomien G, Ross S, Cremer K, Kukuk GM, Epplen JT, Hoffjan S. Analysis of the C19orf12 and WDR45 genes in patients with neurodegeneration with brain iron accumulation. J Neurol Sci 2015; 349:105-9. [DOI: 10.1016/j.jns.2014.12.036] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2014] [Revised: 11/24/2014] [Accepted: 12/24/2014] [Indexed: 12/14/2022]
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221
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Hogarth P. Neurodegeneration with brain iron accumulation: diagnosis and management. J Mov Disord 2015; 8:1-13. [PMID: 25614780 PMCID: PMC4298713 DOI: 10.14802/jmd.14034] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2014] [Revised: 10/15/2014] [Accepted: 10/20/2014] [Indexed: 12/14/2022] Open
Abstract
Neurodegeneration with brain iron accumulation (NBIA) encompasses a group of inherited disorders that share the clinical features of an extrapyramidal movement disorder accompanied by varying degrees of intellectual disability and abnormal iron deposition in the basal ganglia. The genetic basis of ten forms of NBIA is now known. The clinical features of NBIA range from rapid global neurodevelopmental regression in infancy to mild parkinsonism with minimal cognitive impairment in adulthood, with wide variation seen between and within the specific NBIA sub-type. This review describes the clinical presentations, imaging findings, pathologic features, and treatment considerations for this heterogeneous group of disorders.
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Affiliation(s)
- Penelope Hogarth
- Department of Molecular and Medical Genetics, Oregon Health & Science University, Portland, OR, USA
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222
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Abstract
Most neurodegenerative diseases that afflict humans are associated with the intracytoplasmic deposition of aggregate-prone proteins in neurons. Autophagy is a powerful process for removing such proteins. In this Review, we consider how certain neurodegenerative diseases may be associated with impaired autophagy and how this may affect pathology. We also discuss how autophagy induction may be a plausible therapeutic strategy for some conditions and review studies in various models that support this hypothesis. Finally, we briefly describe some of the signaling pathways that may be amenable to therapeutic targeting for these goals.
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223
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Yuan L, Wu S, Xu H, Xiao J, Yang Z, Xia H, Liu A, Hu P, Lu A, Chen Y, Xu F, Deng H. Identification of a novel PHEX mutation in a Chinese family with X-linked hypophosphatemic rickets using exome sequencing. Biol Chem 2015; 396:27-33. [PMID: 25060345 DOI: 10.1515/hsz-2014-0187] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Accepted: 07/20/2014] [Indexed: 01/23/2023]
Abstract
Abstract
Familial hypophosphatemic rickets (HR), the most common inherited form of rickets, is a group of inherited renal phosphate wasting disorders characterized by growth retardation, rickets with bone deformities, osteomalacia, poor dental development, and hypophosphatemia. The purpose of this study was to identify the genetic defect responsible for familial HR in a four-generation Chinese Han pedigree by exome sequencing and Sanger sequencing. Clinical features include skeletal deformities, teeth abnormalities, hearing impairments and variable serum phosphate level in patients of this family. A novel deletion mutation, c.1553delT (p.F518Sfs*4), was identified in the X-linked phosphate regulating endopeptidase homolog gene (PHEX). The mutation is predicted to result in prematurely truncated and loss-of-function PHEX protein. Our data suggest that exome sequencing is a powerful tool to discover mutation(s) in HR, a disorder with genetic and clinical heterogeneity. The findings may also provide new insights into the cause and diagnosis of HR, and have implications for genetic counseling and clinical management.
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224
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Schneider SA. Clinical Phenomenology and Genetics of Other Parkinsonian Syndromes Associated with Either Dystonia or Spasticity. Mov Disord 2015. [DOI: 10.1016/b978-0-12-405195-9.00057-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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225
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Rosic N, Kaniewska P, Chan CKK, Ling EYS, Edwards D, Dove S, Hoegh-Guldberg O. Early transcriptional changes in the reef-building coral Acropora aspera in response to thermal and nutrient stress. BMC Genomics 2014; 15:1052. [PMID: 25467196 PMCID: PMC4301396 DOI: 10.1186/1471-2164-15-1052] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2014] [Accepted: 11/12/2014] [Indexed: 11/10/2022] Open
Abstract
Background Changes to the environment as a result of human activities can result in a range of impacts on reef building corals that include coral bleaching (reduced concentrations of algal symbionts), decreased coral growth and calcification, and increased incidence of diseases and mortality. Understanding how elevated temperatures and nutrient concentration affect early transcriptional changes in corals and their algal endosymbionts is critically important for evaluating the responses of coral reefs to global changes happening in the environment. Here, we investigated the expression of genes in colonies of the reef-building coral Acropora aspera exposed to short-term sub-lethal levels of thermal (+6°C) and nutrient stress (ammonium-enrichment: 20 μM). Results The RNA-Seq data provided hundreds of differentially expressed genes (DEGs) corresponding to various stress regimes, with 115 up- and 78 down-regulated genes common to all stress regimes. A list of DEGs included up-regulated coral genes like cytochrome c oxidase and NADH-ubiquinone oxidoreductase and up-regulated photosynthetic genes of algal origin, whereas coral GFP-like fluorescent chromoprotein and sodium/potassium-transporting ATPase showed reduced transcript levels. Taxonomic analyses of the coral holobiont disclosed the dominant presence of transcripts from coral (~70%) and Symbiodinium (~10-12%), as well as ~15-20% of unknown sequences which lacked sequence identity to known genes. Gene ontology analyses revealed enriched pathways, which led to changes in the dynamics of protein networks affecting growth, cellular processes, and energy requirement. Conclusions In corals with preserved symbiont physiological performance (based on Fv/Fm, photo-pigment and symbiont density), transcriptomic changes and DEGs provided important insight into early stages of the stress response in the coral holobiont. Although there were no signs of coral bleaching after exposure to short-term thermal and nutrient stress conditions, we managed to detect oxidative stress and apoptotic changes on a molecular level and provide a list of prospective stress biomarkers for both partners in symbiosis. Consequently, our findings are important for understanding and anticipating impacts of anthropogenic global climate change on coral reefs. Electronic supplementary material The online version of this article (doi:10.1186/1471-2164-15-1052) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Nedeljka Rosic
- School of Biological Sciences, The University of Queensland, Brisbane Qld 4072, Australia.
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226
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Basal ganglia calcification in a patient with beta-propeller protein-associated neurodegeneration. Pediatr Neurol 2014; 51:843-5. [PMID: 25301227 DOI: 10.1016/j.pediatrneurol.2014.08.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2014] [Revised: 08/24/2014] [Accepted: 08/26/2014] [Indexed: 12/28/2022]
Abstract
BACKGROUND Beta-propeller protein-associated neurodegeneration is a newly described X-linked dominant condition due to heterozygous mutations in WDR45. The condition is associated with characteristic changes on brain magnetic resonance imaging. Previous literature relating to this disorder has not specifically referred to intracranial calcification. METHODS A female patient presented with significant developmental delay in early childhood and subsequently demonstrated neurodegeneration with progressive dystonia and dementia in her third decade. Brain magnetic resonance imaging revealed low signal in the substantia nigra and both globus pallidi on T2-weighted imaging, with no eye-of-the-tiger sign. Computed tomography revealed bilateral dense calcification of the globus pallidus. We performed Sanger sequencing of the WDR45 gene in the patient and her parents. RESULTS We identified a heterozygous c.488del C p.Pro163Argfs*34 variant in exon 8 of WDR45. Neither parent carried the same mutation, indicating that the molecular change had occurred de novo. CONCLUSIONS Although the characteristic features of beta-propeller protein-associated neurodegeneration were present in our patient, the observation of basal ganglia calcification was considered atypical. Previous descriptions of basal ganglia calcification in individuals with neuronal brain iron accumulation led us to review the frequency of calcification in these disorders.
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227
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Thost AK, Dönnes P, Kohlbacher O, Proikas-Cezanne T. Fluorescence-based imaging of autophagy progression by human WIPI protein detection. Methods 2014; 75:69-78. [PMID: 25462558 DOI: 10.1016/j.ymeth.2014.11.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 11/13/2014] [Accepted: 11/16/2014] [Indexed: 12/24/2022] Open
Abstract
Central to the process of macroautophagy (hereafter autophagy) is the formation of autophagosomes, double-membrane vesicles that sequester cytoplasmic cargo, including proteins, lipids and organelles, for lysosomal degradation and macromolecule recycling. Tight regulation of both autophagic activity and capacity is crucial to secure cellular homeostasis and aberrant autophagy is tightly linked to the development of many human diseases. Hence it is of great importance to accurately measure autophagy progression in health and disease. Members of the human WIPI β-propeller proteins associate with autophagosomal membranes due to specific phosphatidylinositol 3-phosphate (PtdIns3P) binding at the onset of autophagy. The specific autophagosomal localization of both WIPI1 and WIPI2 (refered to as WIPI puncta) has been employed to assess autophagy using fluorescence microscopy methods, such as confocal and live-cell video microscopy and was extended for automated high-throughput image acquisition and analyses procedures. We here provide an overview on the employment of human WIPI members for the assessment of autophagy in higher eukaryotic cells, suitable for systems biology approaches such as mathematical modelling.
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Affiliation(s)
- Ann-Katrin Thost
- Autophagy Laboratory, Department of Molecular Biology, Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany
| | - Pierre Dönnes
- Applied Bioinformatics, Center for Bioinformatics, Quantitative Biology Center, and Department of Computer Science, Eberhard Karls University Tuebingen, Sand 14, 72076 Tuebingen, Germany
| | - Oliver Kohlbacher
- Applied Bioinformatics, Center for Bioinformatics, Quantitative Biology Center, and Department of Computer Science, Eberhard Karls University Tuebingen, Sand 14, 72076 Tuebingen, Germany; International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Developmental Biology and Eberhard Karls University Tuebingen, Spemannstr. 35-39, 72076 Tuebingen, Germany
| | - Tassula Proikas-Cezanne
- Autophagy Laboratory, Department of Molecular Biology, Interfaculty Institute of Cell Biology, Eberhard Karls University Tuebingen, Auf der Morgenstelle 15, 72076 Tuebingen, Germany; International Max Planck Research School 'From Molecules to Organisms', Max Planck Institute for Developmental Biology and Eberhard Karls University Tuebingen, Spemannstr. 35-39, 72076 Tuebingen, Germany.
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228
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Abstract
The introduction of next generation sequencing (NGS) has led to an exponential increase of elucidated genetic causes in both extremely rare diseases and common but heterogeneous disorders. It can be applied to the whole or to selected parts of the genome (genome or exome sequencing, gene panels). NGS is not only useful in large extended families with linkage information, but may also be applied to detect de novo mutations or mosaicism in sporadic patients without a prior hypothesis about the mutated gene. Currently, NGS is applied in both research and clinical settings, and there is a rapid transition of research findings to diagnostic applications. These developments may greatly help to minimize the "diagnostic odyssey" for patients as whole-genome analysis can be performed in a few days at reasonable costs compared with gene-by-gene analysis based on Sanger sequencing following diverse clinical tests. Despite the enthusiasm about NGS, one has to keep in mind its limitations, such as a coverage and accuracy of < 100%, resulting in missing variants and false positive findings. In addition, variant interpretation is challenging as there is usually more than one candidate variant found. Therefore, there is an urgent need to define standards for NGS with respect to run quality and variant interpretation, as well as mechanisms of quality control. Further, there are ethical challenges including incidental findings and how to guide unaffected probands seeking direct-to-customer testing. However, taken together, the application of NGS in research and diagnostics provides a tremendous opportunity to better serve our patients.
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Affiliation(s)
- Katja Lohmann
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Christine Klein
- Institute of Neurogenetics, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
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229
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Hamdan FF, Srour M, Capo-Chichi JM, Daoud H, Nassif C, Patry L, Massicotte C, Ambalavanan A, Spiegelman D, Diallo O, Henrion E, Dionne-Laporte A, Fougerat A, Pshezhetsky AV, Venkateswaran S, Rouleau GA, Michaud JL. De novo mutations in moderate or severe intellectual disability. PLoS Genet 2014; 10:e1004772. [PMID: 25356899 PMCID: PMC4214635 DOI: 10.1371/journal.pgen.1004772] [Citation(s) in RCA: 295] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Accepted: 09/22/2014] [Indexed: 01/09/2023] Open
Abstract
Genetics is believed to have an important role in intellectual disability (ID). Recent studies have emphasized the involvement of de novo mutations (DNMs) in ID but the extent to which they contribute to its pathogenesis and the identity of the corresponding genes remain largely unknown. Here, we report a screen for DNMs in subjects with moderate or severe ID. We sequenced the exomes of 41 probands and their parents, and confirmed 81 DNMs affecting the coding sequence or consensus splice sites (1.98 DNMs/proband). We observed a significant excess of de novo single nucleotide substitutions and loss-of-function mutations in these cases compared to control subjects, suggesting that at least a subset of these variations are pathogenic. A total of 12 likely pathogenic DNMs were identified in genes previously associated with ID (ARID1B, CHD2, FOXG1, GABRB3, GATAD2B, GRIN2B, MBD5, MED13L, SETBP1, TBR1, TCF4, WDR45), resulting in a diagnostic yield of ∼29%. We also identified 12 possibly pathogenic DNMs in genes (HNRNPU, WAC, RYR2, SET, EGR1, MYH10, EIF2C1, COL4A3BP, CHMP2A, PPP1CB, VPS4A, PPP2R2B) that have not previously been causally linked to ID. Interestingly, no case was explained by inherited mutations. Protein network analysis indicated that the products of many of these known and candidate genes interact with each other or with products of other ID-associated genes further supporting their involvement in ID. We conclude that DNMs represent a major cause of moderate or severe ID.
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Affiliation(s)
| | - Myriam Srour
- CHU Sainte-Justine Research Center, Montreal, Canada
- Division of Pediatric Neurology, Montreal Children's Hospital, Montreal, Canada
| | | | - Hussein Daoud
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | | | - Lysanne Patry
- CHU Sainte-Justine Research Center, Montreal, Canada
| | | | | | - Dan Spiegelman
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Ousmane Diallo
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Edouard Henrion
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | | | - Anne Fougerat
- CHU Sainte-Justine Research Center, Montreal, Canada
| | | | | | - Guy A. Rouleau
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Jacques L. Michaud
- CHU Sainte-Justine Research Center, Montreal, Canada
- Department of Pediatrics and Department of Neurosciences, University of Montreal, Montreal, Canada
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230
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Okamoto N, Ikeda T, Hasegawa T, Yamamoto Y, Kawato K, Komoto T, Imoto I. Early manifestations of BPAN in a pediatric patient. Am J Med Genet A 2014; 164A:3095-9. [PMID: 25263061 DOI: 10.1002/ajmg.a.36779] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 08/14/2014] [Indexed: 02/02/2023]
Abstract
Neurodegeneration with brain iron accumulation (NBIA) comprises a clinically and genetically heterogeneous group of progressive brain disorders with several distinguishable subtypes. Recently, WDR45 mutations were reported in patients with β-propeller protein-associated neurodegeneration (BPAN), characterized by early intellectual disability followed by delayed progressive motor and cognitive deterioration with onset in the second to third decade. BPAN has a distinct brain magnetic resonance imaging (MRI) pattern showing iron deposition in the globus pallidus and substantia nigra. To date, many of the BPAN patients have been diagnosed in adulthood. Here, we report on 6-year-old girl with BPAN diagnosed by whole exome sequencing. She showed Rett syndrome-like manifestations, a peculiar facial appearance and mildly elevated serum enzymes. Brain iron accumulation was detected by T2*-weighted MRI and T2-star weighted angiography (SWAN). This unique combination of clinical and neuroimaging features may be helpful for early diagnosis of BPAN.
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Affiliation(s)
- Nobuhiko Okamoto
- Department of Medical Genetics, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan
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231
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Polajnar M, Zerovnik E. Impaired autophagy: a link between neurodegenerative and neuropsychiatric diseases. J Cell Mol Med 2014; 18:1705-11. [PMID: 25139375 PMCID: PMC4196646 DOI: 10.1111/jcmm.12349] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2014] [Accepted: 05/16/2014] [Indexed: 12/12/2022] Open
Abstract
Protein misfolding, and subsequent aggregation have been proven as the leading cause of most known dementias. Many of these, in addition to neurodegeneration, show profound changes in behaviour and thinking, thus, psychiatric symptoms. On the basis of the observation that progressive myoclonic epilepsies and neurodegenerative diseases share some common features of neurodegeneration, we proposed autophagy as a possible common impairment in these diseases. Here, we argue along similar lines for some neuropsychiatric conditions, among them depression and schizophrenia. We propose that existing and new therapies for these seemingly different diseases could be augmented with drugs used for neurodegenerative or neuropsychiatric diseases, respectively, among them some which modulate or augment autophagy.
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Affiliation(s)
- Mira Polajnar
- Department of Biochemistry and Molecular and Structural Biology, Jožef Stefan Institute, Ljubljana, Slovenia
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232
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Ozawa T, Koide R, Nakata Y, Saitsu H, Matsumoto N, Takahashi K, Nakano I, Orimo S. A novel WDR45 mutation in a patient with static encephalopathy of childhood with neurodegeneration in adulthood (SENDA). Am J Med Genet A 2014; 164A:2388-90. [PMID: 25044655 PMCID: PMC4278411 DOI: 10.1002/ajmg.a.36635] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 04/30/2014] [Indexed: 11/17/2022]
Abstract
Static encephalopathy of childhood with neurodegeneration in adulthood (SENDA) is an X-linked dominant neurodegenerative disorder, and is classified as a subtype of neurodegeneration with brain iron accumulation. Recently, de novo heterozygous mutations in WDR45 at Xp11.23 have been reported in patients with SENDA. We report the clinical and neuroradiological findings of a patient with SENDA with a novel c.322del mutation in WDR45. In this patient, characteristic MRI findings were useful for diagnosis. © 2014 The Authors. American Journal of Medical Genetics published by Wiley Periodicals, Inc.
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Affiliation(s)
- Tadashi Ozawa
- Department of Neurology, Tokyo Metropolitan Neurological Hospital, Fuchu, Tokyo, Japan
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233
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Abstract
Parkinson’s disease (PD) is a progressively debilitating neurodegenerative syndrome. Although best described as a movement disorder, the condition has prominent autonomic, cognitive, psychiatric, sensory and sleep components. Striatal dopaminergic innervation and nigral neurons are progressively lost, with associated Lewy pathology readily apparent on autopsy. Nevertheless, knowledge of the molecular events leading to this pathophysiology is limited. Current therapies offer symptomatic benefit but they fail to slow progression and patients continue to deteriorate. Recent discoveries in sporadic, Mendelian and more complex forms of parkinsonism provide novel insight into disease etiology; 28 genes, including those encoding alpha-synuclein (SNCA), leucine-rich repeat kinase 2 (LRRK2) and microtubule-associated protein tau (MAPT), have been linked and/or associated with PD. A consensus regarding the affected biological pathways and molecular processes has also started to emerge. In early-onset and more a typical PD, deficits in mitophagy pathways and lysosomal function appear to be prominent. By contrast, in more typical late-onset PD, chronic, albeit subtle, dysfunction in synaptic transmission, early endosomal trafficking and receptor recycling, as well as chaperone-mediated autophagy, provide a unifying synthesis of the molecular pathways involved. Disease-modification (neuroprotection) is no longer such an elusive goal given the unparalleled opportunity for diagnosis, translational neuroscience and therapeutic development provided by genetic discovery.
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Affiliation(s)
- Michelle K Lin
- Djavad Mowafaghian Centre for Brain Health, Centre for Applied Neurogenetics, Department of Medical Genetics, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
| | - Matthew J Farrer
- Djavad Mowafaghian Centre for Brain Health, Centre for Applied Neurogenetics, Department of Medical Genetics, University of British Columbia, Vancouver, BC V6T 1Z3, Canada
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234
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Martinez-Fernandez R, Caballol N, Castrillo L, Krack P. Freezing of Backward Gait. Mov Disord Clin Pract 2014; 1:255-257. [PMID: 30713861 DOI: 10.1002/mdc3.12046] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2014] [Revised: 04/22/2014] [Accepted: 04/30/2014] [Indexed: 11/10/2022] Open
Affiliation(s)
- Raul Martinez-Fernandez
- Movement Disorder Unit Department of Psychiatry and Neurology CHU de Grenoble, Joseph Fourier University, and INSERM, Unit 836, Grenoble Institut des Neurosciences Grenoble France
| | - Nuria Caballol
- Neurology Department Hospital de Sant Joan Despí Moisès Broggi Barcelona Spain
| | - Laura Castrillo
- Radiology Department Hospital de Sant Joan Despí Moisès Broggi Barcelona Spain
| | - Paul Krack
- Movement Disorder Unit Department of Psychiatry and Neurology CHU de Grenoble, Joseph Fourier University, and INSERM, Unit 836, Grenoble Institut des Neurosciences Grenoble France
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235
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Cif L, Kurian MA, Gonzalez V, Garcia‐Ptacek S, Roujeau T, Gelisse P, Moura de Ribeiro AM, Crespel A, MacPherson L, Coubes P. Atypical PLA2G6-Associated Neurodegeneration: Social Communication Impairment, Dystonia and Response to Deep Brain Stimulation. Mov Disord Clin Pract 2014; 1:128-131. [PMID: 30363890 PMCID: PMC6183017 DOI: 10.1002/mdc3.12030] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 03/21/2014] [Accepted: 03/28/2014] [Indexed: 11/10/2022] Open
Affiliation(s)
- Laura Cif
- Département de NeurochirurgieCHRU MontpellierHôpital Gui de ChauliacMontpellierFrance
- INSERM, U661MontpellierFrance
- Université de Montpellier 1MontpellierFrance
- CNRS UMR5203Institut de Génomique FonctionnelleMontpellierFrance
- Département des Neurosciences CliniquesLaboratoire de Recherche en NeuroimagerieCentre Hospitalier Universitaire VaudoisUniversité de LausanneLausanneSwitzerland
| | - Manju A. Kurian
- Neurosciences UnitInstitute of Child Health, LondonUnited Kingdom
- Department of NeurologyGreat Ormond Street HospitalLondonUnited Kingdom
| | - Victoria Gonzalez
- Département de NeurochirurgieCHRU MontpellierHôpital Gui de ChauliacMontpellierFrance
- INSERM, U661MontpellierFrance
- Université de Montpellier 1MontpellierFrance
- CNRS UMR5203Institut de Génomique FonctionnelleMontpellierFrance
| | - Sara Garcia‐Ptacek
- Department of NeurobiologyCare Sciences and SocietyKarolinska InstitutetStockholmSweden
| | - Thomas Roujeau
- Département de NeurochirurgieCHRU MontpellierHôpital Gui de ChauliacMontpellierFrance
| | - Philippe Gelisse
- Epilepsy UnitUniversity Hospital of MontpellierMontpellierFrance
| | | | - Arielle Crespel
- Epilepsy UnitUniversity Hospital of MontpellierMontpellierFrance
| | - Lesley MacPherson
- Department of RadiologyBirmingham Children's HospitalBirminghamUnited Kingdom
| | - Philippe Coubes
- Département de NeurochirurgieCHRU MontpellierHôpital Gui de ChauliacMontpellierFrance
- INSERM, U661MontpellierFrance
- Université de Montpellier 1MontpellierFrance
- CNRS UMR5203Institut de Génomique FonctionnelleMontpellierFrance
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236
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Illingworth MA, Meyer E, Chong WK, Manzur AY, Carr LJ, Younis R, Hardy C, McDonald F, Childs AM, Stewart B, Warren D, Kneen R, King MD, Hayflick SJ, Kurian MA. PLA2G6-associated neurodegeneration (PLAN): further expansion of the clinical, radiological and mutation spectrum associated with infantile and atypical childhood-onset disease. Mol Genet Metab 2014; 112:183-9. [PMID: 24745848 PMCID: PMC4048546 DOI: 10.1016/j.ymgme.2014.03.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 03/21/2014] [Indexed: 11/18/2022]
Abstract
Phospholipase A2 associated neurodegeneration (PLAN) is a major phenotype of autosomal recessive Neurodegeneration with Brain Iron Accumulation (NBIA). We describe the clinical phenotypes, neuroimaging features and PLA2G6 mutations in 5 children, of whom 4 presented with infantile neuroaxonal dystrophy (INAD). One other patient was diagnosed with the onset of PLAN in childhood, and our report highlights the diagnostic challenges associated with this atypical PLAN subtype. In this series, the neuroradiological relevance of classical PLAN features as well as apparent claval hypertrophy' is explored. Novel PLA2G6 mutations were identified in all patients. PLAN should be considered not only in patients presenting with a classic INAD phenotype but also in older patients presenting later in childhood with non-specific progressive neurological features including social communication difficulties, gait disturbance, dyspraxia, neuropsychiatric symptoms and extrapyramidal motor features.
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Affiliation(s)
- M A Illingworth
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - E Meyer
- Neurosciences Unit, UCL-Institute of Child Health, London, UK
| | - W K Chong
- Department of Radiology, Great Ormond Street Hospital, London, UK
| | - A Y Manzur
- Dubowitz Neuromuscular Centre for Congenital Muscular Dystrophies and Myopathies, Great Ormond Street Hospital, London, UK
| | - L J Carr
- Department of Neurology, Great Ormond Street Hospital, London, UK
| | - R Younis
- West Midlands Regional Genetics, Birmingham Women's Hospital, Birmingham, UK
| | - C Hardy
- West Midlands Regional Genetics, Birmingham Women's Hospital, Birmingham, UK
| | - F McDonald
- West Midlands Regional Genetics, Birmingham Women's Hospital, Birmingham, UK
| | - A M Childs
- Department of Paediatric Neurology, Leeds General Infirmary, Leeds, UK
| | - B Stewart
- Department of Paediatrics, York Teaching Hospitals NHS Foundation Trust, York, UK
| | - D Warren
- Department of Neuroradiology, Leeds teaching Hospitals, Leeds. UK
| | - R Kneen
- Department of Neurology, Alder Hey Children's Hospital, Liverpool, UK
| | - M D King
- Department of Paediatric Neurology, Children's University Hospital, Temple Street, Dublin, Ireland
| | - S J Hayflick
- Department of Molecular & Medical Genetics, OR Health & Science University, Portland 97239, USA; Department of Paediatrics, OR Health & Science University, Portland 97239, USA; Department of Neurology, OR Health & Science University, Portland 97239, USA
| | - M A Kurian
- Department of Neurology, Great Ormond Street Hospital, London, UK; Neurosciences Unit, UCL-Institute of Child Health, London, UK.
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237
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Doorn JM, Kruer MC. Newly characterized forms of neurodegeneration with brain iron accumulation. Curr Neurol Neurosci Rep 2014; 13:413. [PMID: 24142851 DOI: 10.1007/s11910-013-0413-9] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Neurodegeneration with brain iron accumulation (NBIA) comprises a group of brain iron deposition syndromes that lead to mixed extrapyramidal features and progressive dementia. Historically, there has not been a clearly identifiable molecular cause for many patients with clinical and radiologic features of NBIA. Recent discoveries have shown that mutations in C19orf12 or WDR45 can lead to NBIA. C19orf12 mutations are inherited in an autosomal recessive manner, and lead to a syndrome similar to that caused by mutations in PANK2 or PLA2G6. In contrast, WDR45 mutations lead to a distinct form of NBIA characterized by spasticity and intellectual disability in childhood followed by the subacute onset of dystonia-parkinsonism in adulthood. WDR45 mutations act in an X-linked dominant manner. Although the function of C19orf12 is largely unknown, WDR45 plays a key role in autophagy. Each of these new forms of NBIA thus leads to a distinct clinical syndrome, and together they implicate new cellular pathways in the pathogenesis of these disorders.
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Affiliation(s)
- Joshua M Doorn
- Departments of Pediatrics and Neurosciences, Sanford School of Medicine, University of South Dakota, Vermillion, SD, USA
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238
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Levi S, Finazzi D. Neurodegeneration with brain iron accumulation: update on pathogenic mechanisms. Front Pharmacol 2014; 5:99. [PMID: 24847269 PMCID: PMC4019866 DOI: 10.3389/fphar.2014.00099] [Citation(s) in RCA: 110] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 04/17/2014] [Indexed: 12/21/2022] Open
Abstract
Perturbation of iron distribution is observed in many neurodegenerative disorders, including Alzheimer’s and Parkinson’s disease, but the comprehension of the metal role in the development and progression of such disorders is still very limited. The combination of more powerful brain imaging techniques and faster genomic DNA sequencing procedures has allowed the description of a set of genetic disorders characterized by a constant and often early accumulation of iron in specific brain regions and the identification of the associated genes; these disorders are now collectively included in the category of neurodegeneration with brain iron accumulation (NBIA). So far 10 different genetic forms have been described but this number is likely to increase in short time. Two forms are linked to mutations in genes directly involved in iron metabolism: neuroferritinopathy, associated to mutations in the FTL gene and aceruloplasminemia, where the ceruloplasmin gene product is defective. In the other forms the connection with iron metabolism is not evident at all and the genetic data let infer the involvement of other pathways: Pank2, Pla2G6, C19orf12, COASY, and FA2H genes seem to be related to lipid metabolism and to mitochondria functioning, WDR45 and ATP13A2 genes are implicated in lysosomal and autophagosome activity, while the C2orf37 gene encodes a nucleolar protein of unknown function. There is much hope in the scientific community that the study of the NBIA forms may provide important insight as to the link between brain iron metabolism and neurodegenerative mechanisms and eventually pave the way for new therapeutic avenues also for the more common neurodegenerative disorders. In this work, we will review the most recent findings in the molecular mechanisms underlining the most common forms of NBIA and analyze their possible link with brain iron metabolism.
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Affiliation(s)
- Sonia Levi
- Proteomic of Iron Metabolism, Vita-Salute San Raffaele University Milano, Italy ; San Raffaele Scientific Institute Milano, Italy
| | - Dario Finazzi
- Department of Molecular and Translational Medicine, University of Brescia Brescia, Italy ; Spedali Civili di Brescia Brescia, Italy
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239
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Michaud JL, Lachance M, Hamdan FF, Carmant L, Lortie A, Diadori P, Major P, Meijer IA, Lemyre E, Cossette P, Mefford HC, Rouleau GA, Rossignol E. The genetic landscape of infantile spasms. Hum Mol Genet 2014; 23:4846-58. [PMID: 24781210 DOI: 10.1093/hmg/ddu199] [Citation(s) in RCA: 136] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Infantile spasms (IS) is an early-onset epileptic encephalopathy of unknown etiology in ∼40% of patients. We hypothesized that unexplained IS cases represent a large collection of rare single-gene disorders. We investigated 44 children with unexplained IS using comparative genomic hybridisation arrays (aCGH) (n = 44) followed by targeted sequencing of 35 known epilepsy genes (n = 8) or whole-exome sequencing (WES) of familial trios (n = 18) to search for rare inherited or de novo mutations. aCGH analysis revealed de novo variants in 7% of patients (n = 3/44), including a distal 16p11.2 duplication, a 15q11.1q13.1 tetrasomy and a 2q21.3-q22.2 deletion. Furthermore, it identified a pathogenic maternally inherited Xp11.2 duplication. Targeted sequencing was informative for ARX (n = 1/14) and STXBP1 (n = 1/8). In contrast, sequencing of a panel of 35 known epileptic encephalopathy genes (n = 8) did not identify further mutations. Finally, WES (n = 18) was very informative, with an excess of de novo mutations identified in genes predicted to be involved in neurodevelopmental processes and/or known to be intolerant to functional variations. Several pathogenic mutations were identified, including de novo mutations in STXBP1, CASK and ALG13, as well as recessive mutations in PNPO and ADSL, together explaining 28% of cases (5/18). In addition, WES identified 1-3 de novo variants in 64% of remaining probands, pointing to several interesting candidate genes. Our results indicate that IS are genetically heterogeneous with a major contribution of de novo mutations and that WES is significantly superior to targeted re-sequencing in identifying detrimental genetic variants involved in IS.
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Affiliation(s)
- Jacques L Michaud
- Department of Pediatrics and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHU Ste-Justine Research Center, Montréal, QC, Canada
| | | | - Fadi F Hamdan
- CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Lionel Carmant
- Department of Pediatrics and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Anne Lortie
- Department of Pediatrics and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Paola Diadori
- Department of Pediatrics and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Philippe Major
- Department of Pediatrics and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Inge A Meijer
- CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Emmanuelle Lemyre
- Department of Pediatrics and CHU Ste-Justine Research Center, Montréal, QC, Canada
| | - Patrick Cossette
- Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHUM, Montréal, QC, Canada
| | - Heather C Mefford
- Department of Pediatrics, University of Washington, Seattle, WA, USA and
| | - Guy A Rouleau
- Department of Neurosciences, Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Elsa Rossignol
- Department of Pediatrics and Department of Neurosciences, Université de Montréal, Montréal, QC, Canada, CHU Ste-Justine Research Center, Montréal, QC, Canada,
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240
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De novo WDR45 mutation in a patient showing clinically Rett syndrome with childhood iron deposition in brain. J Hum Genet 2014; 59:292-5. [PMID: 24621584 DOI: 10.1038/jhg.2014.18] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 02/10/2014] [Accepted: 02/18/2014] [Indexed: 11/09/2022]
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder mostly caused by MECP2 mutations. We identified a de novo WDR45 mutation, which caused a subtype of neurodegeneration with brain iron accumulation, in a patient showing clinically typical RTT. The mutation (c.830+1G>A) led to aberrant splicing in lymphoblastoid cells. Sequential brain magnetic resonance imaging demonstrated that iron deposition in the globus pallidus and the substantia nigra was observed as early as at 11 years of age. Because the patient showed four of the main RTT diagnostic criteria, WDR45 should be investigated in patients with RTT without MECP2 mutations.
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241
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Ng J, Zhen J, Meyer E, Erreger K, Li Y, Kakar N, Ahmad J, Thiele H, Kubisch C, Rider NL, Morton DH, Strauss KA, Puffenberger EG, D'Agnano D, Anikster Y, Carducci C, Hyland K, Rotstein M, Leuzzi V, Borck G, Reith MEA, Kurian MA. Dopamine transporter deficiency syndrome: phenotypic spectrum from infancy to adulthood. ACTA ACUST UNITED AC 2014; 137:1107-19. [PMID: 24613933 PMCID: PMC3959557 DOI: 10.1093/brain/awu022] [Citation(s) in RCA: 109] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Dopamine transporter deficiency syndrome is an SLC6A3-related progressive infantile-onset parkinsonism-dystonia that mimics cerebral palsy. Ng et al. describe clinical features and molecular findings in a new cohort of patients. They report infants with classical disease, as well as young adults manifesting as atypical juvenile-onset parkinsonism-dystonia, thereby expanding the disease spectrum. Dopamine transporter deficiency syndrome due to SLC6A3 mutations is the first inherited dopamine ‘transportopathy’ to be described, with a classical presentation of early infantile-onset progressive parkinsonism dystonia. In this study we have identified a new cohort of patients with dopamine transporter deficiency syndrome, including, most significantly, atypical presentation later in childhood with a milder disease course. We report the detailed clinical features, molecular genetic findings and in vitro functional investigations undertaken for adult and paediatric cases. Patients presenting with parkinsonism dystonia or a neurotransmitter profile characteristic of dopamine transporter deficiency syndrome were recruited for study. SLC6A3 mutational analysis was undertaken in all patients. The functional consequences of missense variants on the dopamine transporter were evaluated by determining the effect of mutant dopamine transporter on dopamine uptake, protein expression and amphetamine-mediated dopamine efflux using an in vitro cellular heterologous expression system. We identified eight new patients from five unrelated families with dopamine transporter deficiency syndrome. The median age at diagnosis was 13 years (range 1.5–34 years). Most significantly, the case series included three adolescent males with atypical dopamine transporter deficiency syndrome of juvenile onset (outside infancy) and progressive parkinsonism dystonia. The other five patients in the cohort presented with classical infantile-onset parkinsonism dystonia, with one surviving into adulthood (currently aged 34 years) and labelled as having ‘juvenile parkinsonism’. All eight patients harboured homozygous or compound heterozygous mutations in SLC6A3, of which the majority are previously unreported variants. In vitro studies of mutant dopamine transporter demonstrated multifaceted loss of dopamine transporter function. Impaired dopamine uptake was universally present, and more severely impacted in dopamine transporter mutants causing infantile-onset rather than juvenile-onset disease. Dopamine transporter mutants also showed diminished dopamine binding affinity, reduced cell surface transporter, loss of post-translational dopamine transporter glycosylation and failure of amphetamine-mediated dopamine efflux. Our data series expands the clinical phenotypic continuum of dopamine transporter deficiency syndrome and indicates that there is a phenotypic spectrum from infancy (early onset, rapidly progressive disease) to childhood/adolescence and adulthood (later onset, slower disease progression). Genotype–phenotype analysis in this cohort suggests that higher residual dopamine transporter activity is likely to contribute to postponing disease presentation in these later-onset adult cases. Dopamine transporter deficiency syndrome remains under-recognized and our data highlights that dopamine transporter deficiency syndrome should be considered as a differential diagnosis for both infantile- and juvenile-onset movement disorders, including cerebral palsy and juvenile parkinsonism.
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Affiliation(s)
- Joanne Ng
- 1 Neurosciences Unit, UCL Institute of Child Health, London, UK
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242
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Rathore GS, Schaaf CP, Stocco AJ. Novel mutation of the WDR45 gene causing beta-propeller protein-associated neurodegeneration. Mov Disord 2014; 29:574-5. [PMID: 24610255 DOI: 10.1002/mds.25868] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 02/09/2014] [Accepted: 02/19/2014] [Indexed: 11/08/2022] Open
Affiliation(s)
- Geetanjali S Rathore
- Department of Neurology and Developmental Neuroscience, Texas Children's Hospital, Baylor College of Medicine, Houston, Texas, USA
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243
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Ebrahimi-Fakhari D. Autophagy and neurodegeneration - genetic findings in SENDA syndrome, a subtype of neurodegeneration with brain iron accumulation, provide a novel link. Mov Disord 2014; 28:1050. [PMID: 23939684 DOI: 10.1002/mds.25563] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Accepted: 05/16/2013] [Indexed: 11/07/2022] Open
Affiliation(s)
- Darius Ebrahimi-Fakhari
- Division of Inherited Metabolic Diseases and Pediatric Neurology, Department of Pediatrics, Heidelberg Children's Hospital, Ruprecht-Karls University, Heidelberg, Germany
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244
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Shen W, Henry AG, Paumier KL, Li L, Mou K, Dunlop J, Berger Z, Hirst WD. Inhibition of glucosylceramide synthase stimulates autophagy flux in neurons. J Neurochem 2014; 129:884-94. [PMID: 24494600 DOI: 10.1111/jnc.12672] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2013] [Revised: 01/24/2014] [Accepted: 01/29/2014] [Indexed: 01/16/2023]
Abstract
Aggregate-prone mutant proteins, such as α-synuclein and huntingtin, play a prominent role in the pathogenesis of various neurodegenerative disorders; thus, it has been hypothesized that reducing the aggregate-prone proteins may be a beneficial therapeutic strategy for these neurodegenerative disorders. Here, we identified two previously described glucosylceramide (GlcCer) synthase inhibitors, DL-threo-1-Phenyl-2-palmitoylamino-3-morpholino-1-propanol and Genz-123346(Genz), as enhancers of autophagy flux. We also demonstrate that GlcCer synthase inhibitors exert their effects on autophagy by inhibiting AKT-mammalian target of rapamycin (mTOR) signaling. More importantly, siRNA knock down of GlcCer synthase had the similar effect as pharmacological inhibition, confirming the on-target effect. In addition, we discovered that inhibition of GlcCer synthase increased the number and size of lysosomal/late endosomal structures. Although inhibition of GlcCer synthase decreases levels of mutant α-synuclein in neurons, it does so, according to our data, through autophagy-independent mechanisms. Our findings demonstrate a direct link between glycosphingolipid biosynthesis and autophagy in primary neurons, which may represent a novel pathway with potential therapeutic value for the treatment of Parkinson's disease. Inhibition of GlcCer synthase enhances autophagy by inhibiting AKT-mTOR signaling, and increases the number and size of lysosomal/late endosomal structures. Furthermore, inhibition of GlcCer synthase decreased levels of mutant α-synuclein in neurons, which may represent a potential therapeutic target for Parkinson's disease.
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Affiliation(s)
- Wei Shen
- Pfizer Neuroscience Research Unit, Cambridge, Massachusetts, USA
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245
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Verhoeven WM, Egger JI, Koolen DA, Yntema H, Olgiati S, Breedveld GJ, Bonifati V, van de Warrenburg BP. Beta-propeller protein-associated neurodegeneration (BPAN), a rare form of NBIA: Novel mutations and neuropsychiatric phenotype in three adult patients. Parkinsonism Relat Disord 2014; 20:332-6. [DOI: 10.1016/j.parkreldis.2013.11.019] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 11/21/2013] [Accepted: 11/30/2013] [Indexed: 01/08/2023]
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246
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Abstract
Purpose of review The aims of this review is to suggest a new nomenclature and classification system for the diseases currently categorized as neurodegeneration with brain iron accumulation (NBIA) or dystonia-parkinsonism, and to discuss the mechanisms implicated in the pathogenesis of these diseases. Recent findings NBIA is a disease category encompassing syndromes with iron accumulation and prominent dystonia–parkinsonism. However, as there are many diseases with similar clinical presentations but without iron accumulation and/or known genetic cause, the current classification system and nomenclature remain confusing. The pathogenetic mechanisms of these diseases and the causes of gross iron accumulation and significant burden of neuroaxonal spheroids are also elusive. Recent genetic and functional studies have identified surprising links between NBIA, Parkinson's disease and lysosomal storage disorders (LSD) with the common theme being a combined lysosomal–mitochondrial dysfunction. We hypothesize that mitochondria and lysosomes form a functional continuum with a predominance of mitochondrial and lysosomal pathways in NBIA and LSD, respectively, and with Parkinson's disease representing an intermediate form of disease. Summary During the past 18 months, important advances have been made towards understanding the genetic and pathological underpinnings of the pallidopyramidal syndromes with important implications for clinical practice and future treatment developments.
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Abstract
PURPOSE OF REVIEW The dystonias are a common but complex group of disorders that show considerable variation in cause and clinical presentation. The purpose of this review is to highlight the most important discoveries and insights from across the field over the period of the past 18 months. RECENT FINDINGS Five new genes for primary dystonia (PRRT2, CIZ1, ANO3, TUBB4A and GNAL) have made their appearance in the literature. New subtypes of neuronal brain iron accumulation have been delineated and linked to mutations in C19orf12 and WDR45, while a new treatable form of dystonia with brain manganese deposition related to mutations in SLC30A10 has been described. At the same time, the phenotypes of other forms of dystonic syndromes have been expanded or linked together. Finally, there has been increasing recognition of both the extramotor phenotype in dystonia and the part played by the cerebellum in its pathophysiology. SUMMARY Recently, there has been unprecedented change in the scientific landscape with respect to the cause of various dystonic syndromes that is likely to make a direct impact on clinical practice in the near future. Understanding the genetic cause of these syndromes and the often wide phenotypic variation in their presentations will improve diagnosis and treatment. With time, these discoveries may also lead to much-needed progress in elucidating the underlying pathophysiology of dystonia.
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248
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Dusi S, Valletta L, Haack TB, Tsuchiya Y, Venco P, Pasqualato S, Goffrini P, Tigano M, Demchenko N, Wieland T, Schwarzmayr T, Strom TM, Invernizzi F, Garavaglia B, Gregory A, Sanford L, Hamada J, Bettencourt C, Houlden H, Chiapparini L, Zorzi G, Kurian MA, Nardocci N, Prokisch H, Hayflick S, Gout I, Tiranti V. Exome sequence reveals mutations in CoA synthase as a cause of neurodegeneration with brain iron accumulation. Am J Hum Genet 2014; 94:11-22. [PMID: 24360804 DOI: 10.1016/j.ajhg.2013.11.008] [Citation(s) in RCA: 134] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Accepted: 11/14/2013] [Indexed: 11/19/2022] Open
Abstract
Neurodegeneration with brain iron accumulation (NBIA) comprises a clinically and genetically heterogeneous group of disorders with progressive extrapyramidal signs and neurological deterioration, characterized by iron accumulation in the basal ganglia. Exome sequencing revealed the presence of recessive missense mutations in COASY, encoding coenzyme A (CoA) synthase in one NBIA-affected subject. A second unrelated individual carrying mutations in COASY was identified by Sanger sequence analysis. CoA synthase is a bifunctional enzyme catalyzing the final steps of CoA biosynthesis by coupling phosphopantetheine with ATP to form dephospho-CoA and its subsequent phosphorylation to generate CoA. We demonstrate alterations in RNA and protein expression levels of CoA synthase, as well as CoA amount, in fibroblasts derived from the two clinical cases and in yeast. This is the second inborn error of coenzyme A biosynthesis to be implicated in NBIA.
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Affiliation(s)
- Sabrina Dusi
- Unit of Molecular Neurogenetics - Pierfranco and Luisa Mariani Center for the study of Mitochondrial Disorders in Children, IRCCS Foundation Neurological Institute "C. Besta," 20126 Milan, Italy
| | - Lorella Valletta
- Unit of Molecular Neurogenetics - Pierfranco and Luisa Mariani Center for the study of Mitochondrial Disorders in Children, IRCCS Foundation Neurological Institute "C. Besta," 20126 Milan, Italy
| | - Tobias B Haack
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany; Institute of Human Genetics, Helmholtz Zentrum München, 85764 Munich, Germany
| | - Yugo Tsuchiya
- Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - Paola Venco
- Unit of Molecular Neurogenetics - Pierfranco and Luisa Mariani Center for the study of Mitochondrial Disorders in Children, IRCCS Foundation Neurological Institute "C. Besta," 20126 Milan, Italy
| | - Sebastiano Pasqualato
- Crystallography Unit, Department of Experimental Oncology, European Institute of Oncology, IFOM-IEO Campus, 20139 Milan, Italy
| | - Paola Goffrini
- Department of Life Sciences, University of Parma, 43124 Parma, Italy
| | - Marco Tigano
- Department of Life Sciences, University of Parma, 43124 Parma, Italy
| | - Nikita Demchenko
- Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - Thomas Wieland
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Munich, Germany
| | - Thomas Schwarzmayr
- Institute of Human Genetics, Helmholtz Zentrum München, 85764 Munich, Germany
| | - Tim M Strom
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany; Institute of Human Genetics, Helmholtz Zentrum München, 85764 Munich, Germany
| | - Federica Invernizzi
- Unit of Molecular Neurogenetics - Pierfranco and Luisa Mariani Center for the study of Mitochondrial Disorders in Children, IRCCS Foundation Neurological Institute "C. Besta," 20126 Milan, Italy
| | - Barbara Garavaglia
- Unit of Molecular Neurogenetics - Pierfranco and Luisa Mariani Center for the study of Mitochondrial Disorders in Children, IRCCS Foundation Neurological Institute "C. Besta," 20126 Milan, Italy
| | - Allison Gregory
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, OR 97329, USA
| | - Lynn Sanford
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, OR 97329, USA
| | - Jeffrey Hamada
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, OR 97329, USA
| | - Conceição Bettencourt
- UCL Institute of Neurology and The National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Henry Houlden
- UCL Institute of Neurology and The National Hospital for Neurology and Neurosurgery, Queen Square, London WC1N 3BG, UK
| | - Luisa Chiapparini
- Unit of Neuroradiology, IRCCS Foundation Neurological Institute "C. Besta," 20133 Milan, Italy
| | - Giovanna Zorzi
- Unit of Child Neurology, IRCCS Foundation Neurological Institute "C. Besta," 20133 Milan, Italy
| | - Manju A Kurian
- Neurosciences Unit, UCL-Institute of Child Health, Great Ormond Street Hospital, London WC1N 3JH, UK; Department of Neurology, Great Ormond Street Hospital, London WC1N 3JH, UK
| | - Nardo Nardocci
- Unit of Child Neurology, IRCCS Foundation Neurological Institute "C. Besta," 20133 Milan, Italy
| | - Holger Prokisch
- Institute of Human Genetics, Technische Universität München, 81675 Munich, Germany; Institute of Human Genetics, Helmholtz Zentrum München, 85764 Munich, Germany
| | - Susan Hayflick
- Department of Molecular & Medical Genetics, Oregon Health & Science University, Portland, OR 97329, USA
| | - Ivan Gout
- Institute of Structural and Molecular Biology, University College London, London WC1E 6BT, UK
| | - Valeria Tiranti
- Unit of Molecular Neurogenetics - Pierfranco and Luisa Mariani Center for the study of Mitochondrial Disorders in Children, IRCCS Foundation Neurological Institute "C. Besta," 20126 Milan, Italy.
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249
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Tonekaboni SH, Mollamohammadi M. Neurodegeneration with brain iron accumulation: an overview. IRANIAN JOURNAL OF CHILD NEUROLOGY 2014; 8:1-8. [PMID: 25657764 PMCID: PMC4307362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/01/2014] [Revised: 11/10/2014] [Accepted: 11/15/2014] [Indexed: 12/01/2022]
Abstract
OBJECTIVE Neurodegeneration with brain iron accumulation (NBIA) is a group of neurodegenerative disorder with deposition of iron in the brain (mainly Basal Ganglia) leading to a progressive Parkinsonism, spasticity, dystonia, retinal degeneration, optic atrophy often accompanied by psychiatric manifestations and cognitive decline. 8 of the 10 genetically defined NBIA types are inherited as autosomal recessive and the remaining two by autosomal dominant and X-linked dominant manner. Brain MRI findings are almost specific and show abnormal brain iron deposition in basal ganglia some other related anatomical locations. In some types of NBIA cerebellar atrophy is the major finding in MRI.
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Affiliation(s)
- Seyed Hassan Tonekaboni
- Pediatric Neurology Research Center, Shahid Beheshti University of Medical Sciences (SBMU), Tehran, Iran ; Pediatric Neurology Center of Excellence, Department of Pediatric Neurology, Mofid Children Hospital, Faculty of Medicine, Shahid Beheshti University of Medical Sciences (SBMU), Tehran, Iran
| | - Mohsen Mollamohammadi
- Pediatric Neurology Department, Hazrat Fatemeh Masoumeh Hospital, Qom University of Medical Sciences, Qom, Iran
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250
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Kishi-Itakura C, Koyama-Honda I, Itakura E, Mizushima N. Ultrastructural analysis of autophagosome organization using mammalian autophagy-deficient cells. J Cell Sci 2014; 127:4089-102. [DOI: 10.1242/jcs.156034] [Citation(s) in RCA: 152] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Autophagy is mediated by a unique organelle, the autophagosome. Autophagosome formation involves a number of autophagy-related (ATG) proteins and complicated membrane dynamics. Although the hierarchical relationships of ATG proteins have been investigated, how individual ATG proteins or their complexes contribute to the organization of the autophagic membrane remains largely unknown. Here, systematic ultrastructural analysis of mouse embryonic fibroblasts and HeLa cells deficient in various ATG proteins revealed that the emergence of the isolation membrane (phagophore) requires FIP200/RB1CC1, ATG9A, and PtdIns 3-kinase activity. By contrast, small premature isolation membrane- and autophagosome-like structures were generated in cells lacking VMP1 and ATG2A/B, respectively. The isolation membranes could elongate in cells lacking ATG5, but these did not mature into autophagosomes. We also found that ferritin clusters accumulated at the autophagosome formation site together with p62/SQSTM1 in autophagy-deficient cells. These results reveal the specific functions of these representative ATG proteins in autophagic membrane organization and ATG-independent recruitment of ferritin to the autophagosome formation site.
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