101
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Di Fabio R, Storti E, Tessa A, Pierelli F, Morani F, Santorelli FM. Hereditary spastic paraplegia: pathology, genetics and therapeutic prospects. Expert Opin Orphan Drugs 2016. [DOI: 10.1517/21678707.2016.1153964] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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102
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Wang H, Wang A, Wang D, Bright A, Sency V, Zhou A, Xin B. Early growth and development impairments in patients with ganglioside GM3 synthase deficiency. Clin Genet 2016; 89:625-9. [DOI: 10.1111/cge.12703] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2015] [Revised: 11/18/2015] [Accepted: 11/27/2015] [Indexed: 11/28/2022]
Affiliation(s)
- H. Wang
- DDC Clinic Center for Special Needs Children; Middlefield OH USA
- Department of Pediatrics; Case Western Reserve University School of Medicine; Cleveland OH USA
- Department of Pediatrics; Rainbow Babies & Children's Hospital; Cleveland OH USA
- Department of Molecular Cardiology; Cleveland Clinic; Cleveland OH USA
| | - A. Wang
- DDC Clinic Center for Special Needs Children; Middlefield OH USA
| | - D. Wang
- DDC Clinic Center for Special Needs Children; Middlefield OH USA
| | - A. Bright
- DDC Clinic Center for Special Needs Children; Middlefield OH USA
| | - V. Sency
- DDC Clinic Center for Special Needs Children; Middlefield OH USA
| | - A. Zhou
- Department of Chemistry; Cleveland State University; Cleveland OH USA
| | - B. Xin
- DDC Clinic Center for Special Needs Children; Middlefield OH USA
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103
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Saunders CJ, Moon SH, Liu X, Thiffault I, Coffman K, LePichon JB, Taboada E, Smith LD, Farrow EG, Miller N, Gibson M, Patterson M, Kingsmore SF, Gross RW. Loss of function variants in human PNPLA8 encoding calcium-independent phospholipase A2 γ recapitulate the mitochondriopathy of the homologous null mouse. Hum Mutat 2015; 36:301-6. [PMID: 25512002 DOI: 10.1002/humu.22743] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 12/09/2014] [Indexed: 12/13/2022]
Abstract
Mitochondriopathies are a group of clinically heterogeneous genetic diseases caused by defects in mitochondrial metabolism, bioenergetic efficiency, and/or signaling functions. The large majority of proteins involved in mitochondrial function are encoded by nuclear genes, with many yet to be associated with human disease. We performed exome sequencing on a young girl with a suspected mitochondrial myopathy that manifested as progressive muscle weakness, hypotonia, seizures, poor weight gain, and lactic acidosis. She was compound heterozygous for two frameshift mutations, p.Asn112HisfsX29 and p.Leu659AlafsX4, in the PNPLA8 gene, which encodes mitochondrial calcium-independent phospholipase A2 γ (iPLA2 γ). Western blot analysis of affected muscle displayed the absence of PNPLA8 protein. iPLA2 s are critical mediators of a variety of cellular processes including growth, metabolism, and lipid second messenger generation, exerting their functions through catalyzing the cleavage of the acyl groups in glycerophospholipids. The clinical presentation, muscle histology and the mitochondrial ultrastructural abnormalities of this proband are highly reminiscent of Pnpla8 null mice. Although other iPLA2 -related diseases have been identified, namely, infantile neuroaxonal dystrophy and neutral lipid storage disease with myopathy, this is the first report of PNPLA8-related disease in a human. We suggest PNPLA8 join the increasing list of human genes involved in lipid metabolism associated with neuromuscular diseases due to mitochondrial dysfunction.
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Affiliation(s)
- Carol J Saunders
- Center for Pediatric Genomic Medicine, Children's Mercy Hospitals, Kansas City, Missouri
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104
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Moskot M, Jakóbkiewicz-Banecka J, Smolińska E, Banecki B, Węgrzyn G, Gabig-Cimińska M. Activities of genes controlling sphingolipid metabolism in human fibroblasts treated with flavonoids. Metab Brain Dis 2015; 30. [PMID: 26209177 PMCID: PMC4560762 DOI: 10.1007/s11011-015-9705-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Natural flavonoids such as genistein, kaempferol and daidzein were previously found to be able to reduce efficiency of glycosaminoglycan synthesis in cells of patients suffering from mucopolysaccharidoses, inherited metabolic diseases with often brain disease symptoms. This feature was employed to test these compounds as potential drugs for treatment other neuronopathic lysosomal storage disorders, in which errors in sphingolipid metabolism occur. In this report, on the basis of DNA microarray analyses and quantitative real time PCR experiments, we present evidence that these compounds modify expression of genes coding for enzymes required for metabolism of sphingolipids in human dermal fibroblasts (HDFa). Expression of several genes involved in sphingolipid synthesis was impaired by tested flavonoids. Therefore, it is tempting to speculate that they may be considered as potential drugs in treatment of LSD, in which accumulation of sphingolipids, especially glycosphingolipids, occurs. Nevertheless, further studies on more advances models are required to test this hypothesis and to assess a therapeutic potential for flavonoids in this group of metabolic brain diseases.
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Affiliation(s)
- Marta Moskot
- Laboratory of Molecular Biology (affiliated with the University of Gdańsk), Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Wita Stwosza 59, 80-308 Gdańsk, Poland
| | | | - Elwira Smolińska
- Department of Molecular Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland
| | - Bogdan Banecki
- Department of Molecular and Cellular Biology, Intercollegiate Faculty of Biotechnology UG-MUG, Kładki 24, 80-822 Gdańsk, Poland
| | - Grzegorz Węgrzyn
- Department of Molecular Biology, University of Gdańsk, Wita Stwosza 59, 80-308 Gdańsk, Poland
| | - Magdalena Gabig-Cimińska
- Laboratory of Molecular Biology (affiliated with the University of Gdańsk), Institute of Biochemistry and Biophysics, Polish Academy of Sciences, Wita Stwosza 59, 80-308 Gdańsk, Poland
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105
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Abstract
This review presents principles of glycosylation, describes the relevant glycosylation pathways and their related disorders, and highlights some of the neurological aspects and issues that continue to challenge researchers. More than 100 rare human genetic disorders that result from deficiencies in the different glycosylation pathways are known today. Most of these disorders impact the central and/or peripheral nervous systems. Patients typically have developmental delays/intellectual disabilities, hypotonia, seizures, neuropathy, and metabolic abnormalities in multiple organ systems. Among these disorders there is great clinical diversity because all cell types differentially glycosylate proteins and lipids. The patients have hundreds of misglycosylated products, which afflict a myriad of processes, including cell signaling, cell-cell interaction, and cell migration. This vast complexity in glycan composition and function, along with the limited availability of analytic tools, has impeded the identification of key glycosylated molecules that cause pathologies. To date, few critical target proteins have been pinpointed.
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106
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Glycosphingolipids are modulators of disease pathogenesis in amyotrophic lateral sclerosis. Proc Natl Acad Sci U S A 2015; 112:8100-5. [PMID: 26056266 DOI: 10.1073/pnas.1508767112] [Citation(s) in RCA: 92] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Recent genetic evidence suggests that aberrant glycosphingolipid metabolism plays an important role in several neuromuscular diseases including hereditary spastic paraplegia, hereditary sensory neuropathy type 1, and non-5q spinal muscular atrophy. Here, we investigated whether altered glycosphingolipid metabolism is a modulator of disease course in amyotrophic lateral sclerosis (ALS). Levels of ceramide, glucosylceramide, galactocerebroside, lactosylceramide, globotriaosylceramide, and the gangliosides GM3 and GM1 were significantly elevated in spinal cords of ALS patients. Moreover, enzyme activities (glucocerebrosidase-1, glucocerebrosidase-2, hexosaminidase, galactosylceramidase, α-galactosidase, and β-galactosidase) mediating glycosphingolipid hydrolysis were also elevated up to threefold. Increased ceramide, glucosylceramide, GM3, and hexosaminidase activity were also found in SOD1(G93A) mice, a familial model of ALS. Inhibition of glucosylceramide synthesis accelerated disease course in SOD1(G93A) mice, whereas infusion of exogenous GM3 significantly slowed the onset of paralysis and increased survival. Our results suggest that glycosphingolipids are likely important participants in pathogenesis of ALS and merit further analysis as potential drug targets.
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107
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Kumar KR, Blair NF, Sue CM. An Update on the Hereditary Spastic Paraplegias: New Genes and New Disease Models. Mov Disord Clin Pract 2015; 2:213-223. [PMID: 30838228 DOI: 10.1002/mdc3.12184] [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: 12/19/2014] [Revised: 02/24/2015] [Accepted: 03/19/2015] [Indexed: 02/07/2023] Open
Abstract
Aims The hereditary spastic paraplegias (HSPs) are a heterogeneous group of disorders characterized by spasticity in the lower limbs. We provide an overview of HSP with an emphasis on recent developments. Methods A PubMed search using the term "hereditary spastic paraplegia" and "hereditary spastic paraparesis" was conducted for a period from January 2012 to January 2015. We discuss and critique the major studies in the field over this 36-month period. Results A total of 346 publications were identified, of which 47 were selected for review. We provide an update of the common forms of HSP and include patient videos. We also discuss how next-generation sequencing (NGS) has led to the accelerated discovery of new HSP genes, including B4GALNT1,DDHD1, C19orf12,GBA2,TECPR2,DDHD2, C12orf65,REEP2, and IBA57. Moreover, a single study alone identified 18 previously unknown putative HSP genes and created a model for the protein interactions of HSP, called the "HSPome." Many of the newly reported genes cause rare, complicated, autosomal recessive forms of HSP. NGS also has important clinical applications by facilitating the molecular diagnosis of HSP. Furthermore, common genetic forms of HSP have been studied using new disease models, such as neurons derived from induced pluripotent stem cells. These models have been used to elucidate important disease mechanisms and have served as platforms to screen for candidate drug compounds. Conclusion The field of HSP research has been progressing at a rapid pace. The challenge remains in translating these advances into new targeted disease therapies.
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Affiliation(s)
- Kishore R Kumar
- Departments of Neurology and Neurogenetics Kolling Institute of Medical Research and Royal North Shore Hospital University of Sydney Sydney New South Wales Australia
| | - Nicholas F Blair
- Departments of Neurology and Neurogenetics Kolling Institute of Medical Research and Royal North Shore Hospital University of Sydney Sydney New South Wales Australia
| | - Carolyn M Sue
- Departments of Neurology and Neurogenetics Kolling Institute of Medical Research and Royal North Shore Hospital University of Sydney Sydney New South Wales Australia
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108
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Klebe S, Stevanin G, Depienne C. Clinical and genetic heterogeneity in hereditary spastic paraplegias: from SPG1 to SPG72 and still counting. Rev Neurol (Paris) 2015; 171:505-30. [PMID: 26008818 DOI: 10.1016/j.neurol.2015.02.017] [Citation(s) in RCA: 120] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2014] [Revised: 02/10/2015] [Accepted: 02/19/2015] [Indexed: 12/11/2022]
Abstract
Hereditary spastic paraplegias (HSPs) are genetically determined neurodegenerative disorders characterized by progressive weakness and spasticity of lower limbs, and are among the most clinically and genetically heterogeneous human diseases. All modes of inheritance have been described, and the recent technological revolution in molecular genetics has led to the identification of 76 different spastic gait disease-loci with 59 corresponding spastic paraplegia genes. Autosomal recessive HSP are usually associated with diverse additional features (referred to as complicated forms), contrary to autosomal dominant HSP, which are mostly pure. However, the identification of additional mutations and families has considerably enlarged the clinical spectra, and has revealed a huge clinical variability for almost all HSP; complicated forms have also been described for primary pure HSP subtypes, adding further complexity to the genotype-phenotype correlations. In addition, the introduction of next generation sequencing in clinical practice has revealed a genetic and phenotypic overlap with other neurodegenerative disorders (amyotrophic lateral sclerosis, neuropathies, cerebellar ataxias, etc.) and neurodevelopmental disorders, including intellectual disability. This review aims to describe the most recent advances in the field and to provide genotype-phenotype correlations that could help clinical diagnoses of this heterogeneous group of disorders.
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Affiliation(s)
- S Klebe
- Department of neurology, university hospital Würzburg, Josef-Schneider-Straße 11, 97080 Würzburg, Germany
| | - G Stevanin
- Sorbonne universités, UPMC université Paris 06, 91-105, boulevard de l'Hôpital, 75013 Paris, France; ICM, CNRS UMR 7225, Inserm U 1127, 47/83, boulevard de l'Hôpital, 75013 Paris, France; École pratique des hautes études, 4-14, rue Ferrus, 75014 Paris, France; Département de génétique, AP-HP, hôpital Pitié-Salpêtrière, 47/83, boulevard de l'Hôpital, 75013 Paris, France
| | - C Depienne
- Sorbonne universités, UPMC université Paris 06, 91-105, boulevard de l'Hôpital, 75013 Paris, France; ICM, CNRS UMR 7225, Inserm U 1127, 47/83, boulevard de l'Hôpital, 75013 Paris, France; Département de génétique, AP-HP, hôpital Pitié-Salpêtrière, 47/83, boulevard de l'Hôpital, 75013 Paris, France.
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109
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Coutelier M, Stevanin G, Brice A. Genetic landscape remodelling in spinocerebellar ataxias: the influence of next-generation sequencing. J Neurol 2015; 262:2382-95. [DOI: 10.1007/s00415-015-7725-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2015] [Revised: 03/25/2015] [Accepted: 03/26/2015] [Indexed: 12/23/2022]
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110
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Yoo SW, Motari MG, Susuki K, Prendergast J, Mountney A, Hurtado A, Schnaar RL. Sialylation regulates brain structure and function. FASEB J 2015; 29:3040-53. [PMID: 25846372 DOI: 10.1096/fj.15-270983] [Citation(s) in RCA: 65] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2015] [Accepted: 03/11/2015] [Indexed: 11/11/2022]
Abstract
Every cell expresses a molecularly diverse surface glycan coat (glycocalyx) comprising its interface with its cellular environment. In vertebrates, the terminal sugars of the glycocalyx are often sialic acids, 9-carbon backbone anionic sugars implicated in intermolecular and intercellular interactions. The vertebrate brain is particularly enriched in sialic acid-containing glycolipids termed gangliosides. Human congenital disorders of ganglioside biosynthesis result in paraplegia, epilepsy, and intellectual disability. To better understand sialoglycan functions in the nervous system, we studied brain anatomy, histology, biochemistry, and behavior in mice with engineered mutations in St3gal2 and St3gal3, sialyltransferase genes responsible for terminal sialylation of gangliosides and some glycoproteins. St3gal2/3 double-null mice displayed dysmyelination marked by a 40% reduction in major myelin proteins, 30% fewer myelinated axons, a 33% decrease in myelin thickness, and molecular disruptions at nodes of Ranvier. In part, these changes may be due to dysregulation of ganglioside-mediated oligodendroglial precursor cell proliferation. Neuronal markers were also reduced up to 40%, and hippocampal neurons had smaller dendritic arbors. Young adult St3gal2/3 double-null mice displayed impaired motor coordination, disturbed gait, and profound cognitive disability. Comparisons among sialyltransferase mutant mice provide insights into the functional roles of brain gangliosides and sialoglycoproteins consistent with related human congenital disorders.
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Affiliation(s)
- Seung-Wan Yoo
- *Department of Pharmacology and Molecular Sciences, Department of Neurology, and Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA; Brain Trauma Neuroprotection and Neurorestoration Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA; and International Center for Spinal Cord Injury, Hugo W. Moser Research Institute, Kennedy Krieger, Baltimore, Maryland, USA
| | - Mary G Motari
- *Department of Pharmacology and Molecular Sciences, Department of Neurology, and Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA; Brain Trauma Neuroprotection and Neurorestoration Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA; and International Center for Spinal Cord Injury, Hugo W. Moser Research Institute, Kennedy Krieger, Baltimore, Maryland, USA
| | - Keiichiro Susuki
- *Department of Pharmacology and Molecular Sciences, Department of Neurology, and Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA; Brain Trauma Neuroprotection and Neurorestoration Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA; and International Center for Spinal Cord Injury, Hugo W. Moser Research Institute, Kennedy Krieger, Baltimore, Maryland, USA
| | - Jillian Prendergast
- *Department of Pharmacology and Molecular Sciences, Department of Neurology, and Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA; Brain Trauma Neuroprotection and Neurorestoration Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA; and International Center for Spinal Cord Injury, Hugo W. Moser Research Institute, Kennedy Krieger, Baltimore, Maryland, USA
| | - Andrea Mountney
- *Department of Pharmacology and Molecular Sciences, Department of Neurology, and Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA; Brain Trauma Neuroprotection and Neurorestoration Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA; and International Center for Spinal Cord Injury, Hugo W. Moser Research Institute, Kennedy Krieger, Baltimore, Maryland, USA
| | - Andres Hurtado
- *Department of Pharmacology and Molecular Sciences, Department of Neurology, and Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA; Brain Trauma Neuroprotection and Neurorestoration Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA; and International Center for Spinal Cord Injury, Hugo W. Moser Research Institute, Kennedy Krieger, Baltimore, Maryland, USA
| | - Ronald L Schnaar
- *Department of Pharmacology and Molecular Sciences, Department of Neurology, and Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA; Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA; Brain Trauma Neuroprotection and Neurorestoration Branch, Center for Military Psychiatry and Neuroscience, Walter Reed Army Institute of Research, Silver Spring, Maryland, USA; and International Center for Spinal Cord Injury, Hugo W. Moser Research Institute, Kennedy Krieger, Baltimore, Maryland, USA
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111
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Delving into the complexity of hereditary spastic paraplegias: how unexpected phenotypes and inheritance modes are revolutionizing their nosology. Hum Genet 2015; 134:511-38. [PMID: 25758904 PMCID: PMC4424374 DOI: 10.1007/s00439-015-1536-7] [Citation(s) in RCA: 103] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2014] [Accepted: 02/23/2015] [Indexed: 12/11/2022]
Abstract
Hereditary spastic paraplegias (HSP) are rare neurodegenerative diseases sharing the degeneration of the corticospinal tracts as the main pathological characteristic. They are considered one of the most heterogeneous neurological disorders. All modes of inheritance have been described for the 84 different loci and 67 known causative genes implicated up to now. Recent advances in molecular genetics have revealed clinico-genetic heterogeneity of these disorders including their clinical and genetic overlap with other diseases of the nervous system. The systematic analysis of a large set of genes, including exome sequencing, is unmasking unusual phenotypes or inheritance modes associated with mutations in HSP genes and related genes involved in various neurological diseases. A new nosology may emerge after integration and understanding of these new data to replace the current classification. Collectively, functions of the known genes implicate the disturbance of intracellular membrane dynamics and trafficking as the consequence of alterations of cytoskeletal dynamics, lipid metabolism and organelle structures, which represent in fact a relatively small number of cellular processes that could help to find common curative approaches, which are still lacking.
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112
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Regulatory function of glycosphingolipids in the inflammation and degeneration. Arch Biochem Biophys 2015; 571:58-65. [PMID: 25688919 DOI: 10.1016/j.abb.2015.02.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 01/19/2015] [Accepted: 02/09/2015] [Indexed: 12/26/2022]
Abstract
Recent progress in the biological sciences has revealed that a number of extrinsic and intrinsic environmental factors may cause chronic inflammation. When these insults are persistent or intermittently repeated, regardless of extrinsic or intrinsic origins, homeostasis of our bodies would be disturbed and undergo long-term impact. These situations might give rise to chronic inflammation, leading to various diseases as results of accumulative effects of various inflammatory reactions. Complex carbohydrates expressed mainly on the cell surface have been demonstrated to play roles in fine-tuning of various biological processes to maintain homeostasis of cells, organs and our bodies. When abnormal physicochemical insults and harmful pathogens invade, the fine-tuning including modification of the glycosylation patterns is continuously exerted. Therefore, defects in the proper response with proper glycosylation lead to chronic inflammation and subsequent deterioration of individual tissues and organs. Genetic depletion of sialic acid-containing glycolipids, gangliosides resulted in the inflammation of CNS and neurodegeneration. Lactosylceramide was also reported to mediate neuroinflammation, leading to chronic inflammatory diseases. Defects of globoseries glycolipids resulted in the increased sensitivity to LPS toxicity. Thus, possibilities that manipulation of synthesis and expression of glycosphingolipids may be applicable for the disease control are now proposed.
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113
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Sabourdy F, Astudillo L, Colacios C, Dubot P, Mrad M, Ségui B, Andrieu-Abadie N, Levade T. Monogenic neurological disorders of sphingolipid metabolism. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:1040-51. [PMID: 25660725 DOI: 10.1016/j.bbalip.2015.01.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2014] [Revised: 01/10/2015] [Accepted: 01/12/2015] [Indexed: 10/24/2022]
Abstract
Sphingolipids comprise a wide variety of molecules containing a sphingoid long-chain base that can be N-acylated. These lipids are particularly abundant in the central nervous system, being membrane components of neurons as well as non-neuronal cells. Direct evidence that these brain lipids play critical functions in brain physiology is illustrated by the dramatic consequences of genetic disturbances of their metabolism. Inherited defects of both synthesis and catabolism of sphingolipids are now identified in humans. These monogenic disorders are due to mutations in the genes encoding for the enzymes that catalyze either the formation or degradation of simple sphingolipids such as ceramides, or complex sphingolipids like glycolipids. They cause varying degrees of central nervous system dysfunction, quite similarly to the neurological disorders induced in mice by gene disruption of the corresponding enzymes. Herein, the enzyme deficiencies and metabolic alterations that underlie these diseases are reviewed. Their possible pathophysiological mechanisms and the functions played by sphingolipids one can deduce from these conditions are discussed. This article is part of a Special Issue entitled Brain Lipids.
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Affiliation(s)
- Frédérique Sabourdy
- Institut National de la Santé et de la Recherche Médicale (INSERM) UMR1037, Toulouse, France; Equipe Labellisée Ligue Nationale Contre le Cancer 2013, Centre de Recherches en Cancérologie de Toulouse (CRCT), Université de Toulouse-III Paul Sabatier, Toulouse, France; Laboratoire de Biochimie Métabolique, Institut Fédératif de Biologie, CHU Purpan, Toulouse, France
| | - Leonardo Astudillo
- Institut National de la Santé et de la Recherche Médicale (INSERM) UMR1037, Toulouse, France; Equipe Labellisée Ligue Nationale Contre le Cancer 2013, Centre de Recherches en Cancérologie de Toulouse (CRCT), Université de Toulouse-III Paul Sabatier, Toulouse, France; Service de Médecine Interne, CHU Purpan, Toulouse, France
| | - Céline Colacios
- Institut National de la Santé et de la Recherche Médicale (INSERM) UMR1037, Toulouse, France; Equipe Labellisée Ligue Nationale Contre le Cancer 2013, Centre de Recherches en Cancérologie de Toulouse (CRCT), Université de Toulouse-III Paul Sabatier, Toulouse, France
| | - Patricia Dubot
- Laboratoire de Biochimie Métabolique, Institut Fédératif de Biologie, CHU Purpan, Toulouse, France
| | - Marguerite Mrad
- Institut National de la Santé et de la Recherche Médicale (INSERM) UMR1037, Toulouse, France; Equipe Labellisée Ligue Nationale Contre le Cancer 2013, Centre de Recherches en Cancérologie de Toulouse (CRCT), Université de Toulouse-III Paul Sabatier, Toulouse, France
| | - Bruno Ségui
- Institut National de la Santé et de la Recherche Médicale (INSERM) UMR1037, Toulouse, France; Equipe Labellisée Ligue Nationale Contre le Cancer 2013, Centre de Recherches en Cancérologie de Toulouse (CRCT), Université de Toulouse-III Paul Sabatier, Toulouse, France
| | - Nathalie Andrieu-Abadie
- Institut National de la Santé et de la Recherche Médicale (INSERM) UMR1037, Toulouse, France; Equipe Labellisée Ligue Nationale Contre le Cancer 2013, Centre de Recherches en Cancérologie de Toulouse (CRCT), Université de Toulouse-III Paul Sabatier, Toulouse, France
| | - Thierry Levade
- Institut National de la Santé et de la Recherche Médicale (INSERM) UMR1037, Toulouse, France; Equipe Labellisée Ligue Nationale Contre le Cancer 2013, Centre de Recherches en Cancérologie de Toulouse (CRCT), Université de Toulouse-III Paul Sabatier, Toulouse, France; Laboratoire de Biochimie Métabolique, Institut Fédératif de Biologie, CHU Purpan, Toulouse, France.
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114
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Astudillo L, Sabourdy F, Therville N, Bode H, Ségui B, Andrieu-Abadie N, Hornemann T, Levade T. Human genetic disorders of sphingolipid biosynthesis. J Inherit Metab Dis 2015; 38:65-76. [PMID: 25141825 DOI: 10.1007/s10545-014-9736-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/06/2014] [Accepted: 06/12/2014] [Indexed: 12/19/2022]
Abstract
Monogenic defects of sphingolipid biosynthesis have been recently identified in human patients. These enzyme deficiencies affect the synthesis of sphingolipid precursors, ceramides or complex glycosphingolipids. They are transmitted as autosomal recessive or dominant traits, and their resulting phenotypes often replicate the abnormalities seen in murine models deficient for the corresponding enzymes. In quite good agreement with the known critical roles of sphingolipids in cells from the nervous system and the epidermis, these genetic defects clinically manifest as neurological disorders, including paraplegia, epilepsy or peripheral neuropathies, or present with ichthyosis. The present review summarizes the genetic alterations, biochemical changes and clinical symptoms of this new group of inherited metabolic disorders. Hypotheses regarding the molecular pathophysiology and potential treatments of these diseases are also discussed.
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Affiliation(s)
- Leonardo Astudillo
- Centre de Recherches en Cancérologie de Toulouse (CRCT), Institut National de la Santé et de la Recherche Médicale (INSERM) UMR1037, Team n 4, CHU Rangueil, BP, 84225, 31432, Toulouse, France
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115
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Ng BG, Freeze HH. Human genetic disorders involving glycosylphosphatidylinositol (GPI) anchors and glycosphingolipids (GSL). J Inherit Metab Dis 2015; 38:171-8. [PMID: 25164783 PMCID: PMC4373530 DOI: 10.1007/s10545-014-9752-1] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2014] [Revised: 07/14/2014] [Accepted: 07/17/2014] [Indexed: 12/27/2022]
Abstract
Glycosylation - enabling genes are thought to comprise approximately 1-2 % of the human genome, thus, it is not surprising that more than 100 genetic disorders have been identified in this complex multi-pathway cellular process. Recent advances in next generation sequencing technology (NGS) have led to the discovery of genetic causes of many new disorders and importantly highlighted the broad phenotypes that occur. Here we will focus on two glycosylation pathways that involve lipids; glycosylphosphatidylinositol (GPI) anchors and glycosphingolipids (GSL) with emphasis on the specific gene defects, their biochemical properties, and their expanding clinical spectra. These disorders involve the intersection of two pathways: lipids and carbohydrates. Studies of both pathways were founded on structural biochemistry. Those methods and their more refined and sensitive descendants can both identify the specific genes that cause the disorders and validate the importance of the specific mutations.
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Affiliation(s)
- Bobby G Ng
- Human Genetics Program, Sanford Children's Health Research Center, Sanford-Burnham Medical Research Institute, La Jolla, CA, 92037, USA
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Garcia-Cazorla À, Mochel F, Lamari F, Saudubray JM. The clinical spectrum of inherited diseases involved in the synthesis and remodeling of complex lipids. A tentative overview. J Inherit Metab Dis 2015; 38:19-40. [PMID: 25413954 DOI: 10.1007/s10545-014-9776-6] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/16/2014] [Accepted: 09/23/2014] [Indexed: 12/19/2022]
Abstract
Over one hundred diseases related to inherited defects of complex lipids synthesis and remodeling are now reported. Most of them were described within the last 5 years. New descriptions and phenotypes are expanding rapidly. While the associated clinical phenotype is currently difficult to outline, with only a few patients identified, it appears that all organs and systems may be affected. The main clinical presentations can be divided into (1) Diseases affecting the central and peripheral nervous system. Complex lipid synthesis disorders produce prominent motor manifestations due to upper and/or lower motoneuron degeneration. Motor signs are often complex, associated with other neurological and extra-neurological signs. Three neurological phenotypes, spastic paraparesis, neurodegeneration with brain iron accumulation and peripheral neuropathies, deserve special attention. Many apparently well clinically defined syndromes are not distinct entities, but rather clusters on a continuous spectrum, like for the PNPLA6-associated diseases, extending from Boucher-Neuhauser syndrome via Gordon Holmes syndrome to spastic ataxia and pure hereditary spastic paraplegia; (2) Muscular/cardiac presentations; (3) Skin symptoms mostly represented by syndromic (neurocutaneous) and non syndromic ichthyosis; (4) Retinal dystrophies with syndromic and non syndromic retinitis pigmentosa, Leber congenital amaurosis, cone rod dystrophy, Stargardt disease; (5) Congenital bone dysplasia and segmental overgrowth disorders with congenital lipomatosis; (6) Liver presentations characterized mainly by transient neonatal cholestatic jaundice and non alcoholic liver steatosis with hypertriglyceridemia; and (7) Renal and immune presentations. Lipidomics and molecular functional studies could help to elucidate the mechanism(s) of dominant versus recessive inheritance observed for the same gene in a growing number of these disorders.
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Affiliation(s)
- Àngels Garcia-Cazorla
- Department of Neurology, Neurometabolic Unit, Hospital Sant Joan de Déu and CIBERER, ISCIII, Barcelona, Spain,
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118
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Schiffmann R. The consequences of genetic and pharmacologic reduction in sphingolipid synthesis. J Inherit Metab Dis 2015; 38:77-84. [PMID: 25164785 DOI: 10.1007/s10545-014-9758-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 07/28/2014] [Accepted: 07/31/2014] [Indexed: 10/24/2022]
Abstract
A new therapy based on substrate synthesis reduction in sphingolipidoses is showing promise. The consequences of decreasing sphingolipid synthesis depend on the level at which synthetic blockage occurs and on the extent of the blockage. Complete synthetic blockage may be lethal if it includes all sphingolipids, such as in a global knockout of serine palmitoyltransferase. Partial inhibition of sphingolipid synthetic pathways is usually benign and may have beneficial effects in a number of lysosomal diseases and in more common pathologies, as seen in animal models for atherosclerosis, polycystic kidney disease, diabetes, and asthma. Studies of various forms of sphingolipid synthesis reduction serve to highlight not only the cellular role of these lipids but also the potential risks and therapeutic benefits of pharmacological agents to be used in therapy for human diseases.
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Affiliation(s)
- Raphael Schiffmann
- Institute of Metabolic Disease, Baylor Research Institute, 3812 Elm Street, Dallas, TX, USA,
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Dorboz I, Coutelier M, Bertrand AT, Caberg JH, Elmaleh-Bergès M, Lainé J, Stevanin G, Bonne G, Boespflug-Tanguy O, Servais L. Severe dystonia, cerebellar atrophy, and cardiomyopathy likely caused by a missense mutation in TOR1AIP1. Orphanet J Rare Dis 2014; 9:174. [PMID: 25425325 PMCID: PMC4302636 DOI: 10.1186/s13023-014-0174-9] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 10/28/2014] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Dystonia, cerebellar atrophy, and cardiomyopathy constitute a rare association. METHODS We used homozygosity mapping and whole exome sequencing to determine the mutation, western blot and immunolabelling on cultured fibroblasts to demonstrate the lower expression and the mislocalization of the protein. RESULTS We report on a boy born from consanguineous healthy parents, who presented at three years of age with rapidly progressing dystonia, progressive cerebellar atrophy, and dilated cardiomyopathy. We identified regions of homozygosity and performed whole exome sequencing that revealed a homozygous missense mutation in TOR1AIP1. The mutation, absent in controls, results in a change of a highly conserved glutamic acid to alanine. TOR1AIP1 encodes lamina-associated polypeptide 1 (LAP1), a transmembrane protein ubiquitously expressed in the inner nuclear membrane. LAP1 interacts with torsinA, the protein mutated in DYT1-dystonia. In vitro studies in fibroblasts of the patient revealed reduced expression of LAP1 and its mislocalization and aggregation in the endoplasmic reticulum as underlying pathogenic mechanisms. CONCLUSIONS AND RELEVANCE The pathogenic role of TOR1AIP1 mutation is supported by a) the involvement of a highly conserved amino acid, b) the absence of the mutation in controls, c) the functional interaction of LAP1 with torsinA, and d) mislocalization of LAP1 in patient cells. Of note, cardiomyopathy has been reported in LAP1-null mice and in patients with the TOR1AIP1 nonsense mutation. Other cases will help delineate the clinical spectrum of LAP1-related mutations.
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Affiliation(s)
- Imen Dorboz
- Inserm U1141, Université Paris Diderot-Sorbonne Paris Cité, DHU PROTECT, Paris, F-75019, France.
| | - Marie Coutelier
- Inserm, U1127, Paris, F-75013, France. .,CNRS, UMR 7225, Paris, 75013, France. .,Université Pierre et Marie Curie - Paris 6, UMR_S 1127, Institut du Cerveau et de la Moelle épinière, CHU Pitié-Salpêtrière, 75013, Paris, France. .,Laboratoire de Neurogénétique, Ecole Pratique des Hautes Etudes, Institut du Cerveau et de la Moelle épinière, CHU Pitié-Salpêtrière, 75013, Paris, France. .,Laboratoire de Génétique Humaine, Institut de Duve, UCL, 1200, Bruxelles, Belgium.
| | - Anne T Bertrand
- Inserm, U974, Paris, F-75013, France. .,Université Pierre et Marie Curie - Paris 6, UM 76; CNRS, UMR 7215; Institut de Myologie, Paris, F-75013, France.
| | | | | | - Jeanne Lainé
- Inserm, U974, Paris, F-75013, France. .,Université Pierre et Marie Curie - Paris 6, UM 76; CNRS, UMR 7215; Institut de Myologie, Paris, F-75013, France. .,Département de Physiologie, Université Pierre et Marie Curie - Paris 6, Site Pitié-Salpêtrière, Paris, F-75013, France.
| | - Giovanni Stevanin
- Inserm, U1127, Paris, F-75013, France. .,CNRS, UMR 7225, Paris, 75013, France. .,Université Pierre et Marie Curie - Paris 6, UMR_S 1127, Institut du Cerveau et de la Moelle épinière, CHU Pitié-Salpêtrière, 75013, Paris, France. .,Laboratoire de Neurogénétique, Ecole Pratique des Hautes Etudes, Institut du Cerveau et de la Moelle épinière, CHU Pitié-Salpêtrière, 75013, Paris, France.
| | - Gisèle Bonne
- Inserm, U974, Paris, F-75013, France. .,Université Pierre et Marie Curie - Paris 6, UM 76; CNRS, UMR 7215; Institut de Myologie, Paris, F-75013, France. .,AP-HP, Groupe Hospitalier Pitié-Salpêtrière, U.F. Cardiogénétique et Myogénétique, Service de Biochimie Métabolique, Paris, F-75013, France.
| | - Odile Boespflug-Tanguy
- Inserm U1141, Université Paris Diderot-Sorbonne Paris Cité, DHU PROTECT, Paris, F-75019, France. .,Service de neurologie pédiatrique et des maladies métaboliques, Hôpital Robert Debré, Assistance Publique des Hôpitaux de Paris, 75019, Paris, France.
| | - Laurent Servais
- Service de neurologie pédiatrique et des maladies métaboliques, Hôpital Robert Debré, Assistance Publique des Hôpitaux de Paris, 75019, Paris, France. .,Centre de Référence des Maladies Neuromusculaires, Hôpital de La Citadelle, 4000, Liège, Belgium. .,Institut de Myologie, Bâtiment Babinski, Hôpital de La Pitié Salpêtrière, 48/83 boulevard de l'Hôpital, 75013, Paris, France.
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Abstract
Gangliosides are major cell-surface determinants on all vertebrate neurons. Human congenital disorders of ganglioside biosynthesis invariably result in intellectual disability and are often associated with intractable seizures. To probe the mechanisms of ganglioside functions, affinity-captured ganglioside-binding proteins from rat cerebellar granule neurons were identified by quantitative proteomic mass spectrometry. Of the six proteins that bound selectively to the major brain ganglioside GT1b (GT1b:GM1 > 4; p < 10(-4)), three regulate neurotransmitter receptor trafficking: Thorase (ATPase family AAA domain-containing protein 1), soluble N-ethylmaleimide-sensitive factor (NSF) attachment protein (γ-SNAP), and the transmembrane protein Nicalin. Thorase facilitates endocytosis of GluR2 subunit-containing AMPA-type glutamate receptors (AMPARs) in an ATPase-dependent manner; its deletion in mice results in learning and memory deficits (J. Zhang et al., 2011b). GluR2-containing AMPARs did not bind GT1b, but bound specifically to another ganglioside, GM1. Addition of noncleavable ATP (ATPγS) significantly disrupted ganglioside binding, whereas it enhanced AMPAR association with Thorase, NSF, and Nicalin. Mutant mice lacking GT1b expressed markedly higher brain Thorase, whereas Thorase-null mice expressed higher GT1b. Treatment of cultured hippocampal neurons with sialidase, which cleaves GT1b (and other sialoglycans), resulted in a significant reduction in the size of surface GluR2 puncta. These data support a model in which GM1-bound GluR2-containing AMPARs are functionally segregated from GT1b-bound AMPAR-trafficking complexes. Release of ganglioside binding may enhance GluR2-containing AMPAR association with its trafficking complexes, increasing endocytosis. Disrupting ganglioside biosynthesis may result in reduced synaptic expression of GluR2-contianing AMPARs resulting in intellectual deficits and seizure susceptibility in mice and humans.
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Di Gregorio E, Borroni B, Giorgio E, Lacerenza D, Ferrero M, Lo Buono N, Ragusa N, Mancini C, Gaussen M, Calcia A, Mitro N, Hoxha E, Mura I, Coviello DA, Moon YA, Tesson C, Vaula G, Couarch P, Orsi L, Duregon E, Papotti MG, Deleuze JF, Imbert J, Costanzi C, Padovani A, Giunti P, Maillet-Vioud M, Durr A, Brice A, Tempia F, Funaro A, Boccone L, Caruso D, Stevanin G, Brusco A. ELOVL5 mutations cause spinocerebellar ataxia 38. Am J Hum Genet 2014; 95:209-17. [PMID: 25065913 DOI: 10.1016/j.ajhg.2014.07.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2014] [Accepted: 07/02/2014] [Indexed: 12/18/2022] Open
Abstract
Spinocerebellar ataxias (SCAs) are a heterogeneous group of autosomal-dominant neurodegenerative disorders involving the cerebellum and 23 different genes. We mapped SCA38 to a 56 Mb region on chromosome 6p in a SCA-affected Italian family by whole-genome linkage analysis. Targeted resequencing identified a single missense mutation (c.689G>T [p.Gly230Val]) in ELOVL5. Mutation screening of 456 independent SCA-affected individuals identified the same mutation in two further unrelated Italian families. Haplotyping showed that at least two of the three families shared a common ancestor. One further missense variant (c.214C>G [p.Leu72Val]) was found in a French family. Both missense changes affect conserved amino acids, are predicted to be damaging by multiple bioinformatics tools, and were not identified in ethnically matched controls or within variant databases. ELOVL5 encodes an elongase involved in the synthesis of polyunsaturated fatty acids of the ω3 and ω6 series. Arachidonic acid and docosahexaenoic acid, two final products of the enzyme, were reduced in the serum of affected individuals. Immunohistochemistry on control mice and human brain demonstrated high levels in Purkinje cells. In transfection experiments, subcellular localization of altered ELOVL5 showed a perinuclear distribution with a signal increase in the Golgi compartment, whereas the wild-type showed a widespread signal in the endoplasmic reticulum. SCA38 and SCA34 are examples of SCAs due to mutations in elongase-encoding genes, emphasizing the importance of fatty-acid metabolism in neurological diseases.
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Affiliation(s)
- Eleonora Di Gregorio
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy; Medical Genetics Unit, Azienda Ospedaliera Universitaria Città della Salute e della Scienza, 10126 Torino, Italy
| | - Barbara Borroni
- Department of Neurology, University of Brescia, 25100 Brescia, Italy
| | - Elisa Giorgio
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Daniela Lacerenza
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Marta Ferrero
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Nicola Lo Buono
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Neftj Ragusa
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Cecilia Mancini
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Marion Gaussen
- Institut National de la Santé et de la Recherche Médicale U1127, 75013 Paris, France; Centre National de la Recherche Scientifique UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie (Paris 6) UMR_S 1127, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France; Neurogenetics team, École Pratique des Hautes Études, HéSam Université, 75013 Paris, France
| | - Alessandro Calcia
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Nico Mitro
- Department of Pharmacological and Biomolecular Sciences, University of Milano, 20133 Milano, Italy
| | - Eriola Hoxha
- Neuroscience Institute Cavalieri Ottolenghi, University of Torino, 10043 Orbassano, Italy
| | - Isabella Mura
- Laboratory of Human Genetics, Galliera Hospital, 16128 Genova, Italy
| | | | - Young-Ah Moon
- Department of Molecular Genetics, University of Texas Southwestern Medical Center, Dallas, TX 75390-9046, USA
| | - Christelle Tesson
- Institut National de la Santé et de la Recherche Médicale U1127, 75013 Paris, France; Centre National de la Recherche Scientifique UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie (Paris 6) UMR_S 1127, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France; Neurogenetics team, École Pratique des Hautes Études, HéSam Université, 75013 Paris, France
| | - Giovanna Vaula
- Neurologic Division 1, Department of Neuroscience and Mental Health, Azienda Ospedaliera Universitaria Città della Salute e della Scienza, 10126 Torino, Italy
| | - Philippe Couarch
- Institut National de la Santé et de la Recherche Médicale U1127, 75013 Paris, France; Centre National de la Recherche Scientifique UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie (Paris 6) UMR_S 1127, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France
| | - Laura Orsi
- Neurologic Division 1, Department of Neuroscience and Mental Health, Azienda Ospedaliera Universitaria Città della Salute e della Scienza, 10126 Torino, Italy
| | - Eleonora Duregon
- Department of Oncology, University of Torino at San Luigi Hospital, 10043 Orbassano, Italy
| | - Mauro Giulio Papotti
- Department of Oncology, University of Torino at San Luigi Hospital, 10043 Orbassano, Italy
| | | | - Jean Imbert
- Transcriptomic and Genomic Marseille-Luminy platform, Technological Advances for Genomics and Clinics Laboratory, Institut National de la Santé et de la Recherche Médicale UMR_S 1090, Aix-Marseille University, 13009 Marseille, France
| | - Chiara Costanzi
- Department of Neurology, University of Brescia, 25100 Brescia, Italy
| | | | - Paola Giunti
- Department of Molecular Neuroscience, University College London Institute of Neurology, WC1 N3BG London, UK
| | | | - Alexandra Durr
- Institut National de la Santé et de la Recherche Médicale U1127, 75013 Paris, France; Centre National de la Recherche Scientifique UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie (Paris 6) UMR_S 1127, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France; Fédération de Génétique, Pitié-Salpêtrière Hospital, Assistance Publique - Hôpitaux de Paris, 75013 Paris, France
| | - Alexis Brice
- Institut National de la Santé et de la Recherche Médicale U1127, 75013 Paris, France; Centre National de la Recherche Scientifique UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie (Paris 6) UMR_S 1127, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France; Fédération de Génétique, Pitié-Salpêtrière Hospital, Assistance Publique - Hôpitaux de Paris, 75013 Paris, France
| | - Filippo Tempia
- Neuroscience Institute Cavalieri Ottolenghi, University of Torino, 10043 Orbassano, Italy
| | - Ada Funaro
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy
| | - Loredana Boccone
- Ospedale Regionale Microcitemie, Azienda Unità Sanitaria Locale 8, 09121 Cagliari, Italy
| | - Donatella Caruso
- Neuroscience Institute Cavalieri Ottolenghi, University of Torino, 10043 Orbassano, Italy
| | - Giovanni Stevanin
- Institut National de la Santé et de la Recherche Médicale U1127, 75013 Paris, France; Centre National de la Recherche Scientifique UMR 7225, 75013 Paris, France; Sorbonne Universités, Université Pierre et Marie Curie (Paris 6) UMR_S 1127, Institut du Cerveau et de la Moelle Épinière, 75013 Paris, France; Neurogenetics team, École Pratique des Hautes Études, HéSam Université, 75013 Paris, France; Fédération de Génétique, Pitié-Salpêtrière Hospital, Assistance Publique - Hôpitaux de Paris, 75013 Paris, France
| | - Alfredo Brusco
- Department of Medical Sciences, University of Torino, 10126 Torino, Italy; Medical Genetics Unit, Azienda Ospedaliera Universitaria Città della Salute e della Scienza, 10126 Torino, Italy.
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122
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Platt FM. Sphingolipid lysosomal storage disorders. Nature 2014; 510:68-75. [PMID: 24899306 DOI: 10.1038/nature13476] [Citation(s) in RCA: 226] [Impact Index Per Article: 22.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 03/14/2014] [Indexed: 12/18/2022]
Abstract
Lysosomal storage diseases are inborn errors of metabolism, the hallmark of which is the accumulation, or storage, of macromolecules in the late endocytic system. They are monogenic disorders that occur at a collective frequency of 1 in 5,000 live births and are caused by inherited defects in genes that mainly encode lysosomal proteins, most commonly lysosomal enzymes. A subgroup of these diseases involves the lysosomal storage of glycosphingolipids. Through our understanding of the genetics, biochemistry and, more recently, cellular aspects of sphingolipid storage disorders, we have gained insights into fundamental aspects of cell biology that would otherwise have remained opaque. In addition, study of these disorders has led to significant progress in the development of therapies, several of which are now in routine clinical use. Emerging mechanistic links with more common diseases suggest we need to rethink our current concept of disease boundaries.
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Affiliation(s)
- Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford OX1 3QT, UK
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Peeters K, Chamova T, Jordanova A. Clinical and genetic diversity of SMN1-negative proximal spinal muscular atrophies. ACTA ACUST UNITED AC 2014; 137:2879-96. [PMID: 24970098 PMCID: PMC4208460 DOI: 10.1093/brain/awu169] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Peeters et al. review current knowledge regarding the phenotypes, causative genes, and disease mechanisms associated with proximal SMN1-negative spinal muscular atrophies (SMA). They describe the molecular and cellular functions enriched among causative genes, and discuss the challenges facing the post-genomics era of SMA research. Hereditary spinal muscular atrophy is a motor neuron disorder characterized by muscle weakness and atrophy due to degeneration of the anterior horn cells of the spinal cord. Initially, the disease was considered purely as an autosomal recessive condition caused by loss-of-function SMN1 mutations on 5q13. Recent developments in next generation sequencing technologies, however, have unveiled a growing number of clinical conditions designated as non-5q forms of spinal muscular atrophy. At present, 16 different genes and one unresolved locus are associated with proximal non-5q forms, having high phenotypic variability and diverse inheritance patterns. This review provides an overview of the current knowledge regarding the phenotypes, causative genes, and disease mechanisms associated with proximal SMN1-negative spinal muscular atrophies. We describe the molecular and cellular functions enriched among causative genes, and discuss the challenges in the post-genomics era of spinal muscular atrophy research.
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Affiliation(s)
- Kristien Peeters
- 1 Molecular Neurogenomics Group, Department of Molecular Genetics, VIB, University of Antwerp, Antwerpen 2610, Belgium 2 Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp, Antwerpen 2610, Belgium
| | - Teodora Chamova
- 3 Department of Neurology, Medical University-Sofia, Sofia 1000, Bulgaria
| | - Albena Jordanova
- 1 Molecular Neurogenomics Group, Department of Molecular Genetics, VIB, University of Antwerp, Antwerpen 2610, Belgium 2 Neurogenetics Laboratory, Institute Born-Bunge, University of Antwerp, Antwerpen 2610, Belgium 4 Department of Medical Chemistry and Biochemistry, Molecular Medicine Centre, Medical University-Sofia, Sofia 1431, Bulgaria
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Lo Giudice T, Lombardi F, Santorelli FM, Kawarai T, Orlacchio A. Hereditary spastic paraplegia: clinical-genetic characteristics and evolving molecular mechanisms. Exp Neurol 2014; 261:518-39. [PMID: 24954637 DOI: 10.1016/j.expneurol.2014.06.011] [Citation(s) in RCA: 244] [Impact Index Per Article: 24.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2014] [Revised: 06/07/2014] [Accepted: 06/12/2014] [Indexed: 12/12/2022]
Abstract
Hereditary spastic paraplegia (HSP) is a group of clinically and genetically heterogeneous neurological disorders characterized by pathophysiologic hallmark of length-dependent distal axonal degeneration of the corticospinal tracts. The prominent features of this pathological condition are progressive spasticity and weakness of the lower limbs. To date, 72 spastic gait disease-loci and 55 spastic paraplegia genes (SPGs) have been identified. All modes of inheritance (autosomal dominant, autosomal recessive, and X-linked) have been described. Recently, a late onset spastic gait disorder with maternal trait of inheritance has been reported, as well as mutations in genes not yet classified as spastic gait disease. Several cellular processes are involved in its pathogenesis, such as membrane and axonal transport, endoplasmic reticulum membrane modeling and shaping, mitochondrial function, DNA repair, autophagy, and abnormalities in lipid metabolism and myelination processes. Moreover, recent evidences have been found about the impairment of endosome membrane trafficking in vesicle formation and about the involvement of oxidative stress and mtDNA polymorphisms in the onset of the disease. Interactome networks have been postulated by bioinformatics and biological analyses of spastic paraplegia genes, which would contribute to the development of new therapeutic approaches.
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Affiliation(s)
- Temistocle Lo Giudice
- Laboratorio di Neurogenetica, Centro Europeo di Ricerca sul Cervello (CERC) - Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Santa Lucia, Rome, Italy; Dipartimento di Medicina dei Sistemi, Università di Roma "Tor Vergata", Rome, Italy
| | - Federica Lombardi
- Laboratorio di Neurogenetica, Centro Europeo di Ricerca sul Cervello (CERC) - Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Santa Lucia, Rome, Italy
| | - Filippo Maria Santorelli
- Unità Operativa Complessa di Medicina Molecolare, Neurogenetica e Malattie Neurodegenerative, IRCCS Stella Maris, Pisa, Italy
| | - Toshitaka Kawarai
- Department of Clinical Neuroscience, Institute of Health Biosciences, Graduate School of Medicine, University of Tokushima, Tokushima, Japan
| | - Antonio Orlacchio
- Laboratorio di Neurogenetica, Centro Europeo di Ricerca sul Cervello (CERC) - Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Santa Lucia, Rome, Italy; Dipartimento di Medicina dei Sistemi, Università di Roma "Tor Vergata", Rome, Italy.
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125
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Schnaar RL, Gerardy-Schahn R, Hildebrandt H. Sialic acids in the brain: gangliosides and polysialic acid in nervous system development, stability, disease, and regeneration. Physiol Rev 2014; 94:461-518. [PMID: 24692354 DOI: 10.1152/physrev.00033.2013] [Citation(s) in RCA: 510] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Every cell in nature carries a rich surface coat of glycans, its glycocalyx, which constitutes the cell's interface with its environment. In eukaryotes, the glycocalyx is composed of glycolipids, glycoproteins, and proteoglycans, the compositions of which vary among different tissues and cell types. Many of the linear and branched glycans on cell surface glycoproteins and glycolipids of vertebrates are terminated with sialic acids, nine-carbon sugars with a carboxylic acid, a glycerol side-chain, and an N-acyl group that, along with their display at the outmost end of cell surface glycans, provide for varied molecular interactions. Among their functions, sialic acids regulate cell-cell interactions, modulate the activities of their glycoprotein and glycolipid scaffolds as well as other cell surface molecules, and are receptors for pathogens and toxins. In the brain, two families of sialoglycans are of particular interest: gangliosides and polysialic acid. Gangliosides, sialylated glycosphingolipids, are the most abundant sialoglycans of nerve cells. Mouse genetic studies and human disorders of ganglioside metabolism implicate gangliosides in axon-myelin interactions, axon stability, axon regeneration, and the modulation of nerve cell excitability. Polysialic acid is a unique homopolymer that reaches >90 sialic acid residues attached to select glycoproteins, especially the neural cell adhesion molecule in the brain. Molecular, cellular, and genetic studies implicate polysialic acid in the control of cell-cell and cell-matrix interactions, intermolecular interactions at cell surfaces, and interactions with other molecules in the cellular environment. Polysialic acid is essential for appropriate brain development, and polymorphisms in the human genes responsible for polysialic acid biosynthesis are associated with psychiatric disorders including schizophrenia, autism, and bipolar disorder. Polysialic acid also appears to play a role in adult brain plasticity, including regeneration. Together, vertebrate brain sialoglycans are key regulatory components that contribute to proper development, maintenance, and health of the nervous system.
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Ohmi Y, Ohkawa Y, Tajima O, Sugiura Y, Furukawa K, Furukawa K. Ganglioside deficiency causes inflammation and neurodegeneration via the activation of complement system in the spinal cord. J Neuroinflammation 2014; 11:61. [PMID: 24673754 PMCID: PMC3986855 DOI: 10.1186/1742-2094-11-61] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2013] [Accepted: 02/17/2014] [Indexed: 01/15/2023] Open
Abstract
Background Gangliosides, sialic acid-containing glycosphingolipids, are highly expressed in nervous systems of vertebrates and have been considered to be involved in the development, differentiation, and function of nervous tissues. Recent studies with gene-engineered animals have revealed that they play roles in the maintenance and repair of nervous tissues. In particular, knockout (KO) mice of various ganglioside synthase genes have exhibited progressive neurodegeneration with aging. However, neurological disorders and pathological changes in the spinal cord of these KO mice have not been reported to date. Therefore, we examined neurodegeneration in double knockout (DKO) mice of ganglioside GM2/GD2 synthase (B4GANLT1) and GD3 synthase (ST8SIA1) genes to clarify roles of gangliosides in the spinal cord. Methods Motor neuron function was examined by gait analysis, and sensory function was analyzed by von Frey test. Pathological changes were analyzed by staining tissue sections with Klüver-Barrera staining and by immunohistochemistry with F4/80 and glial fibrillary acidic protein (GFAP). Gene expression profiles were examined by using DNA micro-array of RNAs from the spinal cord of mice. Triple knockout mice were generated by mating DKO and complement component 3 (C3)-KO mice. Gene expression of the complement system and cytokines was examined by reverse transcription-polymerase chain reaction (RT-PCR) as a function of age. Results DKO mice showed progressive deterioration with aging. Correspondingly, they exhibited shrunk spinal cord, reduced thickness of spinal lamina II and III, and reduced neuronal numbers in spinal lamina IX, spinal lamina II, and spinal lamina I. Complement-related genes were upregulated in DKO spinal cord. Moreover, complement activation and inflammatory reactions were detected by GFAP-active astrocyte, microglial accumulation, and increased inflammatory cytokines such as tumor necrosis factor-alpha (TNFα) and interleukin-1-beta (IL-1β). Triple knockout mice showed restoration of reduced neuron numbers in the spinal cord of DKO mice, getting close to levels of wild-type mice. Conclusions Disruption in the architecture of lipid rafts in the spinal cord was not so prominent, suggesting that mechanisms distinct from those reported might be involved in the complement activation in the spinal cord of DKO mice. Gene profiling revealed that inflammation and neurodegeneration in the spinal cord of DKO mice are, at least partly, dependent on complement activation.
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Affiliation(s)
| | | | | | | | | | - Koichi Furukawa
- Department of Biochemistry II, Nagoya University Graduate School of Medicine, 65 Tsurumai, Showa-ku, Nagoya 466-0065, Japan.
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Noreau A, Dion PA, Rouleau GA. Molecular aspects of hereditary spastic paraplegia. Exp Cell Res 2014; 325:18-26. [PMID: 24631291 DOI: 10.1016/j.yexcr.2014.02.021] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2014] [Accepted: 02/16/2014] [Indexed: 11/17/2022]
Abstract
Hereditary spastic paraplegia (HSP) is a clinically and genetically heterogeneous group of neurodegenerative disorders characterized by progressive lower limbs spasticity and weakness. What was first thought to be a small group of rare Mendelian disorder has now become a large group that includes many complex syndromes. While large families with defined modes of inheritance were used for the initial HSP gene discovery, new sequencing technologies have recently allowed the study of small families, with the identification of many new disease causative genes. These discoveries are slowly leading to a better understanding of the molecular mechanisms underlying HSP with the identification of precise disease pathways. These insights may lead to new therapeutic strategies for what is a group of largely untreatable diseases. This review looks at the key players involved in HSP and where they act in their specific pathways.
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Affiliation(s)
- Anne Noreau
- Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada; Université de Montréal, Department of Pathology and Cellular Biology, Montreal, Quebec, Canada
| | - Patrick A Dion
- Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada; Université de Montréal, Department of Pathology and Cellular Biology, Montreal, Quebec, Canada
| | - Guy A Rouleau
- Montreal Neurological Institute and Hospital, Department of Neurology and Neurosurgery, McGill University, Montreal, Quebec, Canada.
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128
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Yao D, McGonigal R, Barrie JA, Cappell J, Cunningham ME, Meehan GR, Fewou SN, Edgar JM, Rowan E, Ohmi Y, Furukawa K, Furukawa K, Brophy PJ, Willison HJ. Neuronal expression of GalNAc transferase is sufficient to prevent the age-related neurodegenerative phenotype of complex ganglioside-deficient mice. J Neurosci 2014; 34:880-91. [PMID: 24431446 PMCID: PMC3891965 DOI: 10.1523/jneurosci.3996-13.2014] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Revised: 11/15/2013] [Accepted: 11/23/2013] [Indexed: 11/21/2022] Open
Abstract
Gangliosides are widely expressed sialylated glycosphingolipids with multifunctional properties in different cell types and organs. In the nervous system, they are highly enriched in both glial and neuronal membranes. Mice lacking complex gangliosides attributable to targeted ablation of the B4galnt1 gene that encodes β-1,4-N-acetylegalactosaminyltransferase 1 (GalNAc-transferase; GalNAcT(-/-)) develop normally before exhibiting an age-dependent neurodegenerative phenotype characterized by marked behavioral abnormalities, central and peripheral axonal degeneration, reduced myelin volume, and loss of axo-glial junction integrity. The cell biological substrates underlying this neurodegeneration and the relative contribution of either glial or neuronal gangliosides to the process are unknown. To address this, we generated neuron-specific and glial-specific GalNAcT rescue mice crossed on the global GalNAcT(-/-) background [GalNAcT(-/-)-Tg(neuronal) and GalNAcT(-/-)-Tg(glial)] and analyzed their behavioral, morphological, and electrophysiological phenotype. Complex gangliosides, as assessed by thin-layer chromatography, mass spectrometry, GalNAcT enzyme activity, and anti-ganglioside antibody (AgAb) immunohistology, were restored in both neuronal and glial GalNAcT rescue mice. Behaviorally, GalNAcT(-/-)-Tg(neuronal) retained a normal "wild-type" (WT) phenotype throughout life, whereas GalNAcT(-/-)-Tg(glial) resembled GalNAcT(-/-) mice, exhibiting progressive tremor, weakness, and ataxia with aging. Quantitative electron microscopy demonstrated that GalNAcT(-/-) and GalNAcT(-/-)-Tg(glial) nerves had significantly increased rates of axon degeneration and reduced myelin volume, whereas GalNAcT(-/-)-Tg(neuronal) and WT appeared normal. The increased invasion of the paranode with juxtaparanodal Kv1.1, characteristically seen in GalNAcT(-/-) and attributed to a breakdown of the axo-glial junction, was normalized in GalNAcT(-/-)-Tg(neuronal) but remained present in GalNAcT(-/-)-Tg(glial) mice. These results indicate that neuronal rather than glial gangliosides are critical to the age-related maintenance of nervous system integrity.
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Affiliation(s)
- Denggao Yao
- Institute of Infection, Immunity, and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Rhona McGonigal
- Institute of Infection, Immunity, and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Jennifer A. Barrie
- Institute of Infection, Immunity, and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Joanna Cappell
- Institute of Infection, Immunity, and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Madeleine E. Cunningham
- Institute of Infection, Immunity, and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Gavin R. Meehan
- Institute of Infection, Immunity, and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Simon N. Fewou
- Institute of Infection, Immunity, and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Julia M. Edgar
- Institute of Infection, Immunity, and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
| | - Edward Rowan
- Strathclyde Institute of Pharmacy and Biomedical Sciences, University of Strathclyde, Glasgow G4 0NR, United Kingdom
| | - Yuhsuke Ohmi
- Department of Biochemistry II, Nagoya University School of Medicine, Nagoya 466-0065, Japan, and
| | - Keiko Furukawa
- Department of Biochemistry II, Nagoya University School of Medicine, Nagoya 466-0065, Japan, and
| | - Koichi Furukawa
- Department of Biochemistry II, Nagoya University School of Medicine, Nagoya 466-0065, Japan, and
| | - Peter J. Brophy
- Centre for Neuroregeneration, University of Edinburgh, Edinburgh EH16 4SB, United Kingdom
| | - Hugh J. Willison
- Institute of Infection, Immunity, and Inflammation, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, G12 8TA, United Kingdom
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129
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Synofzik M, Gonzalez MA, Lourenco CM, Coutelier M, Haack TB, Rebelo A, Hannequin D, Strom TM, Prokisch H, Kernstock C, Durr A, Schöls L, Lima-Martínez MM, Farooq A, Schüle R, Stevanin G, Marques W, Züchner S. PNPLA6 mutations cause Boucher-Neuhauser and Gordon Holmes syndromes as part of a broad neurodegenerative spectrum. ACTA ACUST UNITED AC 2013; 137:69-77. [PMID: 24355708 DOI: 10.1093/brain/awt326] [Citation(s) in RCA: 152] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Boucher-Neuhäuser and Gordon Holmes syndromes are clinical syndromes defined by early-onset ataxia and hypogonadism plus chorioretinal dystrophy (Boucher-Neuhäuser syndrome) or brisk reflexes (Gordon Holmes syndrome). Here we uncover the genetic basis of these two syndromes, demonstrating that both clinically distinct entities are allelic for recessive mutations in the gene PNPLA6. In five of seven Boucher-Neuhäuser syndrome/Gordon Holmes syndrome families, we identified nine rare conserved and damaging mutations by applying whole exome sequencing. Further, by dissecting the complex clinical presentation of Boucher-Neuhäuser syndrome and Gordon Holmes syndrome into its neurological system components, we set out to analyse an additional 538 exomes from families with ataxia (with and without hypogonadism), pure and complex hereditary spastic paraplegia, and Charcot-Marie-Tooth disease type 2. We identified four additional PNPLA6 mutations in spastic ataxia and hereditary spastic paraplegia families, revealing that Boucher-Neuhäuser and Gordon Holmes syndromes in fact represent phenotypic clusters on a spectrum of neurodegenerative diseases caused by mutations in PNPLA6. Structural analysis indicates that the majority of mutations falls in the C-terminal phospholipid esterase domain and likely inhibits the catalytic activity of PNPLA6, which provides the precursor for biosynthesis of the neurotransmitter acetylcholine. Our findings show that PNPLA6 influences a manifold of neuronal systems, from the retina to the cerebellum, upper and lower motor neurons and the neuroendocrine system, with damage of this protein causing an extraordinarily broad continuous spectrum of associated neurodegenerative disease.
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Affiliation(s)
- Matthis Synofzik
- 1 Department of Neurodegenerative Diseases, Hertie-Institute for Clinical Brain Research, University of Tübingen, Germany
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Wakil SM, Monies DM, Ramzan K, Hagos S, Bastaki L, Meyer BF, Bohlega S. Novel B4GALNT1 mutations in a complicated form of hereditary spastic paraplegia. Clin Genet 2013; 86:500-1. [PMID: 24283893 DOI: 10.1111/cge.12312] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 10/31/2013] [Accepted: 11/04/2013] [Indexed: 11/26/2022]
Affiliation(s)
- S M Wakil
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
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131
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Schulze H, Sandhoff K. Sphingolipids and lysosomal pathologies. Biochim Biophys Acta Mol Cell Biol Lipids 2013; 1841:799-810. [PMID: 24184515 DOI: 10.1016/j.bbalip.2013.10.015] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 10/16/2013] [Accepted: 10/19/2013] [Indexed: 01/12/2023]
Abstract
Endocytosed (glyco)sphingolipids are degraded, together with other membrane lipids in a stepwise fashion by endolysosomal enzymes with the help of small lipid binding proteins, the sphingolipid activator proteins (SAPs), at the surface of intraluminal lysosomal vesicles. Inherited defects in a sphingolipid-degrading enzyme or SAP cause the accumulation of the corresponding lipid substrates, including cytotoxic lysosphingolipids, such as galactosylsphingosine and glucosylsphingosine, and lead to a sphingolipidosis. Analysis of patients with prosaposin deficiency revealed the accumulation of intra-endolysosmal vesicles and membrane structures (IM). Feeding of prosaposin reverses the storage, suggesting inner membrane structures as platforms of sphingolipid degradation. Water soluble enzymes can hardly attack sphingolipids embedded in the membrane of inner endolysosomal vesicles. The degradation of sphingolipids with few sugar residues therefore requires the help of the SAPs, and is strongly stimulated by anionic membrane lipids. IMs are rich in anionic bis(monoacylglycero)phosphate (BMP). This article is part of a Special Issue entitled New Frontiers in Sphingolipid Biology.
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Affiliation(s)
- Heike Schulze
- LIMES, Membrane Biology & Lipid Biochemistry Unit, c/o Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Str. 1, D-53115 Bonn, Germany
| | - Konrad Sandhoff
- LIMES, Membrane Biology & Lipid Biochemistry Unit, c/o Kekulé-Institut für Organische Chemie und Biochemie, Universität Bonn, Gerhard-Domagk-Str. 1, D-53115 Bonn, Germany.
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Harlalka GV, Lehman A, Chioza B, Baple EL, Maroofian R, Cross H, Sreekantan-Nair A, Priestman DA, Al-Turki S, McEntagart ME, Proukakis C, Royle L, Kozak RP, Bastaki L, Patton M, Wagner K, Coblentz R, Price J, Mezei M, Schlade-Bartusiak K, Platt FM, Hurles ME, Crosby AH. Mutations in B4GALNT1 (GM2 synthase) underlie a new disorder of ganglioside biosynthesis. ACTA ACUST UNITED AC 2013; 136:3618-24. [PMID: 24103911 PMCID: PMC3859217 DOI: 10.1093/brain/awt270] [Citation(s) in RCA: 105] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Glycosphingolipids are ubiquitous constituents of eukaryotic plasma membranes, and their sialylated derivatives, gangliosides, are the major class of glycoconjugates expressed by neurons. Deficiencies in their catabolic pathways give rise to a large and well-studied group of inherited disorders, the lysosomal storage diseases. Although many glycosphingolipid catabolic defects have been defined, only one proven inherited disease arising from a defect in ganglioside biosynthesis is known. This disease, because of defects in the first step of ganglioside biosynthesis (GM3 synthase), results in a severe epileptic disorder found at high frequency amongst the Old Order Amish. Here we investigated an unusual neurodegenerative phenotype, most commonly classified as a complex form of hereditary spastic paraplegia, present in families from Kuwait, Italy and the Old Order Amish. Our genetic studies identified mutations in B4GALNT1 (GM2 synthase), encoding the enzyme that catalyzes the second step in complex ganglioside biosynthesis, as the cause of this neurodegenerative phenotype. Biochemical profiling of glycosphingolipid biosynthesis confirmed a lack of GM2 in affected subjects in association with a predictable increase in levels of its precursor, GM3, a finding that will greatly facilitate diagnosis of this condition. With the description of two neurological human diseases involving defects in two sequentially acting enzymes in ganglioside biosynthesis, there is the real possibility that a previously unidentified family of ganglioside deficiency diseases exist. The study of patients and animal models of these disorders will pave the way for a greater understanding of the role gangliosides play in neuronal structure and function and provide insights into the development of effective treatment therapies.
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Affiliation(s)
- Gaurav V Harlalka
- 1 Institute of Biomedical and Clinical Science, University of Exeter Medical School, St. Luke's Campus, Heavitree Road, EX1 2LU, Exeter, Devon, UK
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