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Bullock G, Johnson GS, Pattridge SG, Mhlanga-Mutangadura T, Guo J, Cook J, Campbell RS, Vite CH, Katz ML. A Homozygous MAN2B1 Missense Mutation in a Doberman Pinscher Dog with Neurodegeneration, Cytoplasmic Vacuoles, Autofluorescent Storage Granules, and an α-Mannosidase Deficiency. Genes (Basel) 2023; 14:1746. [PMID: 37761886 PMCID: PMC10531151 DOI: 10.3390/genes14091746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
A 7-month-old Doberman Pinscher dog presented with progressive neurological signs and brain atrophy suggestive of a hereditary neurodegenerative disorder. The dog was euthanized due to the progression of disease signs. Microscopic examination of tissues collected at the time of euthanasia revealed massive accumulations of vacuolar inclusions in cells throughout the central nervous system, suggestive of a lysosomal storage disorder. A whole genome sequence generated with DNA from the affected dog contained a likely causal, homozygous missense variant in MAN2B1 that predicted an Asp104Gly amino acid substitution that was unique among whole genome sequences from over 4000 dogs. A lack of detectable α-mannosidase enzyme activity confirmed a diagnosis of a-mannosidosis. In addition to the vacuolar inclusions characteristic of α-mannosidosis, the dog exhibited accumulations of autofluorescent intracellular inclusions in some of the same tissues. The autofluorescence was similar to that which occurs in a group of lysosomal storage disorders called neuronal ceroid lipofuscinoses (NCLs). As in many of the NCLs, some of the storage bodies immunostained strongly for mitochondrial ATP synthase subunit c protein. This protein is not a substrate for α-mannosidase, so its accumulation and the development of storage body autofluorescence were likely due to a generalized impairment of lysosomal function secondary to the accumulation of α-mannosidase substrates. Thus, it appears that storage body autofluorescence and subunit c accumulation are not unique to the NCLs. Consistent with generalized lysosomal impairment, the affected dog exhibited accumulations of intracellular inclusions with varied and complex ultrastructural features characteristic of autophagolysosomes. Impaired autophagic flux may be a general feature of this class of disorders that contributes to disease pathology and could be a target for therapeutic intervention. In addition to storage body accumulation, glial activation indicative of neuroinflammation was observed in the brain and spinal cord of the proband.
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Affiliation(s)
- Garrett Bullock
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - Gary S. Johnson
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - Savannah G. Pattridge
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - Tendai Mhlanga-Mutangadura
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - Juyuan Guo
- Department of Veterinary Pathobiology, College of Veterinary Medicine, University of Missouri, Columbia, MO 65211, USA; (G.B.); (G.S.J.); (S.G.P.); (T.M.-M.); (J.G.)
| | - James Cook
- Specialists in Companion Animal Neurology, Clearwater, FL 33765, USA;
| | - Rebecca S. Campbell
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (R.S.C.); (C.H.V.)
| | - Charles H. Vite
- Department of Clinical Sciences and Advanced Medicine, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; (R.S.C.); (C.H.V.)
| | - Martin L. Katz
- Neurodegenerative Diseases Research Laboratory, Department of Ophthalmology, School of Medicine, University of Missouri, Columbia, MO 65212, USA
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Parenti G, Medina DL, Ballabio A. The rapidly evolving view of lysosomal storage diseases. EMBO Mol Med 2021; 13:e12836. [PMID: 33459519 PMCID: PMC7863408 DOI: 10.15252/emmm.202012836] [Citation(s) in RCA: 97] [Impact Index Per Article: 32.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Revised: 11/09/2020] [Accepted: 11/10/2020] [Indexed: 12/17/2022] Open
Abstract
Lysosomal storage diseases are a group of metabolic disorders caused by deficiencies of several components of lysosomal function. Most commonly affected are lysosomal hydrolases, which are involved in the breakdown and recycling of a variety of complex molecules and cellular structures. The understanding of lysosomal biology has progressively improved over time. Lysosomes are no longer viewed as organelles exclusively involved in catabolic pathways, but rather as highly dynamic elements of the autophagic-lysosomal pathway, involved in multiple cellular functions, including signaling, and able to adapt to environmental stimuli. This refined vision of lysosomes has substantially impacted on our understanding of the pathophysiology of lysosomal disorders. It is now clear that substrate accumulation triggers complex pathogenetic cascades that are responsible for disease pathology, such as aberrant vesicle trafficking, impairment of autophagy, dysregulation of signaling pathways, abnormalities of calcium homeostasis, and mitochondrial dysfunction. Novel technologies, in most cases based on high-throughput approaches, have significantly contributed to the characterization of lysosomal biology or lysosomal dysfunction and have the potential to facilitate diagnostic processes, and to enable the identification of new therapeutic targets.
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Affiliation(s)
- Giancarlo Parenti
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Department of Translational Medical Sciences, Section of Pediatrics, Federico II University, Naples, Italy
| | - Diego L Medina
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Department of Translational Medical Sciences, Section of Pediatrics, Federico II University, Naples, Italy
| | - Andrea Ballabio
- Telethon Institute of Genetics and Medicine, Pozzuoli, Italy.,Department of Translational Medical Sciences, Section of Pediatrics, Federico II University, Naples, Italy.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA.,Jan and Dan Duncan Neurological Research Institute, Texas Children Hospital, Houston, TX, USA.,SSM School for Advanced Studies, Federico II University, Naples, Italy
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3
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Breiden B, Sandhoff K. Mechanism of Secondary Ganglioside and Lipid Accumulation in Lysosomal Disease. Int J Mol Sci 2020; 21:ijms21072566. [PMID: 32272755 PMCID: PMC7178057 DOI: 10.3390/ijms21072566] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 03/26/2020] [Accepted: 04/04/2020] [Indexed: 02/06/2023] Open
Abstract
Gangliosidoses are caused by monogenic defects of a specific hydrolase or an ancillary sphingolipid activator protein essential for a specific step in the catabolism of gangliosides. Such defects in lysosomal function cause a primary accumulation of multiple undegradable gangliosides and glycosphingolipids. In reality, however, predominantly small gangliosides also accumulate in many lysosomal diseases as secondary storage material without any known defect in their catabolic pathway. In recent reconstitution experiments, we identified primary storage materials like sphingomyelin, cholesterol, lysosphingolipids, and chondroitin sulfate as strong inhibitors of sphingolipid activator proteins (like GM2 activator protein, saposin A and B), essential for the catabolism of many gangliosides and glycosphingolipids, as well as inhibitors of specific catabolic steps in lysosomal ganglioside catabolism and cholesterol turnover. In particular, they trigger a secondary accumulation of ganglioside GM2, glucosylceramide and cholesterol in Niemann–Pick disease type A and B, and of GM2 and glucosylceramide in Niemann–Pick disease type C. Chondroitin sulfate effectively inhibits GM2 catabolism in mucopolysaccharidoses like Hurler, Hunter, Sanfilippo, and Sly syndrome and causes a secondary neuronal ganglioside GM2 accumulation, triggering neurodegeneration. Secondary ganglioside and lipid accumulation is furthermore known in many more lysosomal storage diseases, so far without known molecular basis.
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Paton L, Bitoun E, Kenyon J, Priestman DA, Oliver PL, Edwards B, Platt FM, Davies KE. A novel mouse model of a patient mucolipidosis II mutation recapitulates disease pathology. J Biol Chem 2014; 289:26709-26721. [PMID: 25107912 PMCID: PMC4175314 DOI: 10.1074/jbc.m114.586156] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Mucolipidosis II (MLII) is a lysosomal storage disorder caused by loss of N-acetylglucosamine-1-phosphotransferase, which tags lysosomal enzymes with a mannose 6-phosphate marker for transport to the lysosome. In MLII, the loss of this marker leads to deficiency of multiple enzymes and non-enzymatic proteins in the lysosome, leading to the storage of multiple substrates. Here we present a novel mouse model of MLII homozygous for a patient mutation in the GNPTAB gene. Whereas the current gene knock-out mouse model of MLII lacks some of the characteristic features of the human disease, our novel mouse model more fully recapitulates the human pathology, showing growth retardation, skeletal and facial abnormalities, increased circulating lysosomal enzymatic activities, intracellular lysosomal storage, and reduced life span. Importantly, MLII behavioral deficits are characterized for the first time, including impaired motor function and psychomotor retardation. Histological analysis of the brain revealed progressive neurodegeneration in the cerebellum with severe Purkinje cell loss as the underlying cause of the ataxic gait. In addition, based on the loss of Npc2 (Niemann-Pick type C 2) protein expression in the brain, the mice were treated with 2-hydroxypropyl-β-cyclodextrin, a drug previously reported to rescue Purkinje cell death in a mouse model of Niemann-Pick type C disease. No improvement in brain pathology was observed. This indicates that cerebellar degeneration is not primarily triggered by loss of Npc2 function. This study emphasizes the value of modeling MLII patient mutations to generate clinically relevant mouse mutants to elucidate the pathogenic molecular pathways of MLII and address their amenability to therapy.
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Affiliation(s)
- Leigh Paton
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy, and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, United Kingdom and
| | - Emmanuelle Bitoun
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy, and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, United Kingdom and
| | - Janet Kenyon
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy, and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, United Kingdom and
| | - David A Priestman
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Peter L Oliver
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy, and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, United Kingdom and
| | - Benjamin Edwards
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy, and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, United Kingdom and
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
| | - Kay E Davies
- Medical Research Council Functional Genomics Unit, Department of Physiology, Anatomy, and Genetics, University of Oxford, South Parks Road, Oxford OX1 3PT, United Kingdom and.
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Cerebellar alterations and gait defects as therapeutic outcome measures for enzyme replacement therapy in α-mannosidosis. J Neuropathol Exp Neurol 2011; 70:83-94. [PMID: 21157375 DOI: 10.1097/nen.0b013e31820428fa] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
α-Mannosidosis is a rare lysosomal storage disease with accumulation of undegraded mannosyl-linked oligosaccharides in cells throughout the body, most notably in the CNS. This leads to a broad spectrum of neurological manifestations, including progressive intellectual impairment, disturbed motor functions, and cerebellar atrophy. To develop therapeutic outcome measures for enzyme replacement therapy that could be used for human patients, a gene knockout model of α-mannosidosis in mice was analyzed for CNS pathology and motor deficits. In the cerebellar molecular layer, α-mannosidosis mice display clusters of activated Bergman glia, infiltration of phagocytic macrophages, and accumulation of free cholesterol and gangliosides (GM1), notably in regions lacking Purkinje cells. α-Mannosidosis brain lysates also displayed increased expression of Lamp1 and hyperglycosylation of the cholesterol binding protein NPC2. Detailed assessment of motor function revealed age-dependent gait defects in the mice that resemble the disturbed motor function in human patients. Short-term enzyme replacement therapy partially reversed the observed cerebellar pathology with fewer activated macrophages and astrocytes but unchanged levels of hyperglycosylated NPC2, gangliosides, and cholesterol. The present study demonstrates cerebellar alterations in α-mannosidosis mice that relate to the motor deficits and pathological changes seen in human patients and can be used as therapeutic outcome measures.
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Kondagari GS, Ramanathan P, Taylor R. Canine fucosidosis: a neuroprogressive disorder. NEURODEGENER DIS 2011; 8:240-51. [PMID: 21282938 DOI: 10.1159/000322541] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Accepted: 11/04/2010] [Indexed: 11/19/2022] Open
Abstract
The lysosomal storage disease, canine fucosidosis, is caused by the absence of the lysosomal enzyme canine α-L-fucosidase with storage of undegraded fucose-rich material in different organs. Canine fucosidosis is a severe, progressive, fatal neurological disease which results in death or euthanasia and is the only available animal model for this human disease. We analysed the progressive neuropathology from birth to severe clinical disease and related this to the clinical signs. At birth no vacuolation was observed in fucosidosis brain; however, a complex storage presence with vacuolation was well established by 4 months of age, before the clinical signs of motor dysfunction which occurred at 10-12 months of age. Purkinje cell loss, neuronal loss, gliosis, perivascular storage and demyelination accompanied disease progression. Increased vacuolation (15.3-fold increase compared to controls) coincided with advanced motor and mental deterioration in late-stage disease. Significant loss of myelin commenced early, with greatest impact in the cerebellum, and was severe in late disease (1.6- to 1.9-fold decrease) compared to controls (p < 0.05) contributing to clinical signs of motor and mental dysfunction. This detailed description and quantification of the CNS pathology in canine fucosidosis will inform monitoring of the onset, progression and response of this disease to therapy.
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Ledesma MD, Prinetti A, Sonnino S, Schuchman EH. Brain pathology in Niemann Pick disease type A: insights from the acid sphingomyelinase knockout mice. J Neurochem 2011; 116:779-88. [PMID: 21214563 DOI: 10.1111/j.1471-4159.2010.07034.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Severe neurological involvement characterizes Niemann Pick disease (NPD) type A, an inherited disorder caused by loss of function mutations in the gene encoding acid sphingomyelinase (ASM). Mice lacking ASM, which mimic NPD type A, have provided important insights into the aberrant brain phenotypes induced by ASM deficiency. For example, lipid alterations, including the accumulation of sphingolipids, affect the membranes of different subcellular compartments of neurons and glial cells, leading to anomalies in signalling pathways, neuronal polarization, calcium homeostasis, synaptic plasticity, myelin production or immune response. These findings contribute to our understanding of the overall role of sphingolipids and their metabolic enzymes in brain physiology, and pave the way to design and test new therapeutic strategies for type A NPD and other neurodegenerative disorders. Some of these have already been tested in mice lacking ASM with promising results.
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Walkley SU, Zervas M, Siegel DA, Dobrenis K. Gangliosides as Modulators of Dendritogenesis in Storage Disease-Affected and Normal Pyramidal Neurons. Dev Neuropsychol 2010. [DOI: 10.1207/s15326942dn1603_16] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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Walkley SU, Vanier MT. Secondary lipid accumulation in lysosomal disease. BIOCHIMICA ET BIOPHYSICA ACTA 2009; 1793:726-36. [PMID: 19111580 PMCID: PMC4382014 DOI: 10.1016/j.bbamcr.2008.11.014] [Citation(s) in RCA: 159] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/26/2008] [Revised: 11/11/2008] [Accepted: 11/28/2008] [Indexed: 01/22/2023]
Abstract
Lysosomal diseases are inherited metabolic disorders caused by defects in a wide spectrum of lysosomal and a few non-lysosomal proteins. In most cases a single type of primary storage material is identified, which has been used to name and classify the disorders: hence the terms sphingolipidoses, gangliosidoses, mucopolysaccharidoses, glycoproteinoses, and so forth. In addition to this primary storage, however, a host of secondary storage products can also be identified, more often than not having no direct link to the primary protein defect. Lipids - glycosphingolipids and phospholipids, as well as cholesterol - are the most ubiquitous and best studied of these secondary storage materials. While in the past typically considered nonspecific and nonconsequential features of these diseases, newer studies suggest direct links between secondary storage and disease pathogenesis and support the view that understanding all aspects of this sequestration process will provide important insights into the cell biology and treatment of lysosomal disease.
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Affiliation(s)
- Steven U Walkley
- Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Center, Albert Einstein College of Medicine, 1410 Pelham Parkway South, Bronx, NY, USA.
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Crawley AC, Walkley SU. Developmental Analysis of CNS Pathology in the Lysosomal Storage Disease α-Mannosidosis. J Neuropathol Exp Neurol 2007; 66:687-97. [PMID: 17882013 DOI: 10.1097/nen.0b013e31812503b6] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
The lysosomal storage disease alpha-mannosidosis is due to absence or defective function of lysosomal alpha-mannosidase, resulting in primary storage of undegraded mannose-rich oligosaccharides. Disease has been described in humans, cattle, cats, mice, and guinea pigs and is characterized in all species by progressive neurologic deterioration and premature death. We analyzed the neurodegenerative processes relative to clinical disease in alpha-mannosidosis guinea pigs as a human disease model, from birth to end-stage disease. Before the onset of obvious neurologic abnormalities at 2 months, we observed widespread neuronal lysosomal vacuolation including secondary accumulation of GM3 ganglioside, widespread axonal spheroids, and reduced myelination of white matter. Histopathologic changes subsequently showed rapid progression in severity in a pattern common to a number of different lysosomal storage disorders, with additional abnormalities including accumulation of GM2 ganglioside and cholesterol, astrogliosis, neuron loss particularly in the cerebellum, and activation and infiltration of the CNS with microglia/macrophages. End-stage clinical disease was seen at 10 to 14 months of age. Our findings show that complex neuropathologic changes in alpha-mannosidosis guinea pigs are already present at birth, before clinical changes are evident, and similar events are likely to occur in patients with this disorder.
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Affiliation(s)
- Allison C Crawley
- Lysosomal Diseases Research Unit, Department of Genetic Medicine, Children, Youth and Women's Health Service, North Adelaide, SA, Australia.
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Abstract
Carbohydrates have established themselves as the most clinically relevant antigens of those tested and subsequently developed for vaccines against infectious diseases. However, in cancer patients, many of the defined carbohydrate antigens are really altered 'self' antigens and for unclear reasons, the body does not react to them immunologically. Although these self antigens have been found to be potentially suitable targets for immune recognition and killing, the development of vaccines for cancer treatment is actually more challenging compared with those for infectious diseases mainly because of the difficulty associated with breaking the body's immunological tolerance to the antigen. These antigens lack the inherent immunogenicity associated with bacterial antigens and, therefore, methods to enhance immunological recognition and induction of immunity in vivo are under investigation. These include defining the appropriate tumour-associated antigen, successfully synthesizing the antigen to mimic the original molecule, inducing an immune response, and subsequently enhancing the immunological reactivity so that all components can work together. This has been successfully accomplished with several glycolipid and glycoprotein antigens using carriers such as keyhole limpet haemocyanin (KLH) together with a saponin adjuvant, QS-21. Not only can high titre IgM and IgG antibodies be induced, which are specific for the antigen used for immunization, but the antibodies can mediate complement lysis. The approaches for synthesis, conjugation, clinical administration and immunological potential are discussed.
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Affiliation(s)
- Susan F Slovin
- Genitourinary Oncology Service, Memorial Sloan-Kettering Cancer Center, New York 10021, USA.
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Walkley SU. Neurobiology and cellular pathogenesis of glycolipid storage diseases. Philos Trans R Soc Lond B Biol Sci 2003; 358:893-904. [PMID: 12803923 PMCID: PMC1693176 DOI: 10.1098/rstb.2003.1276] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Disorders of lysosomal metabolism often involve the accumulation of specific types of glycolipid, particularly gangliosides, because of either degradative failure or other currently unknown mechanisms. Although the precise role of gangliosides in cells remains enigmatic, the presence of specific abnormalities secondary to ganglioside accumulation in lysosomal diseases has suggested important biological functions. Chief among these is the growth of new dendrites on particular classes of mature neurons secondary to an increase in GM2 ganglioside. That GM2 has also been shown to be elevated in normal immature neurons coincident with dendritic sprouting provides a compelling argument that this ganglioside plays a role in dendritic initiation. This discovery has led to the search for other regulators of dendritic differentiation that may in some way be linked to the expression and/or function of GM2 ganglioside. Principal candidates that have emerged include tyrosine kinase receptors, small GTPases and calcium/calmodulin-dependent protein kinase II. Understanding the mechanism underlying ectopic dendritogenesis in lysosomal diseases can be expected to generate significant insight into the control of dendritic plasticity in normal brain. The detrimental aspects of ganglioside accumulation in storage diseases as well as the potential link between gangliosides and dendritogenesis also provide a strong rationale for developing pharmacological means to manipulate ganglioside expression in neurons.
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Affiliation(s)
- Steven U Walkley
- Sidney Weisner Laboratory of Genetic Neurological Disease, Department of Neuroscience, Rose F. Kennedy Center for Research in Mental Retardation and Human Development, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Heuer GG, Skorupa AF, Prasad Alur RK, Jiang K, Wolfe JH. Accumulation of abnormal amounts of glycosaminoglycans in murine mucopolysaccharidosis type VII neural progenitor cells does not alter the growth rate or efficiency of differentiation into neurons. Mol Cell Neurosci 2001; 17:167-78. [PMID: 11161477 DOI: 10.1006/mcne.2000.0917] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Mucopolysaccharidosis type VII (MPS VII) results from deficiencies in the gene encoding the lysosomal enzyme beta-glucuronidase (GUSB). To study how the genetic and biochemical defects of MPS disease affect neural cell populations, neural progenitor cells (NPCs) were isolated from MPS VII mice and normal littermates. After growth in culture, approximately 90% of cells from both genotypes were nestin positive, a marker for NPCs, and lacked markers associated with lineage commitment. The mutant NPCs contained elevated levels of undegraded glycosaminoglycans (GAGs), the substrate for GUSB. Transduction with a retrovirus-vector expressing normal GUSB resulted in correction of the biochemical defects. Because of the demonstrated roles that GAGs and proteoglycans have in NPC biology and neural development, we tested whether the alterations in GAG metabolism affected MPS VII NPC properties regulated by GAG-containing molecules. MPS VII NPC cultures had growth rates in response to FGF-2 that were similar to normal cultures and the efficiency of differentiation into neurons was the same as with normal cells. Thus, even though isolated NPCs accumulate abnormally high levels of GAGs, these two key developmental properties were not altered when the cells were examined outside the milieu of the diseased brain.
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Affiliation(s)
- G G Heuer
- Department of Pathobiology, Division of Neurology, Center for Comparative Medical Genetics, School of Veterinary Medicine, 34th and Civic Center Boulevard, Philadelphia, Pennsylvania 19104, USA
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Crawley AC, Jones MZ, Bonning LE, Finnie JW, Hopwood JJ. Alpha-mannosidosis in the guinea pig: a new animal model for lysosomal storage disorders. Pediatr Res 1999; 46:501-9. [PMID: 10541310 DOI: 10.1203/00006450-199911000-00003] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alpha-mannosidosis is a lysosomal storage disorder resulting from deficient activity of lysosomal alpha-mannosidase. It has been described previously in humans, cattle, and cats, and is characterized in all of these species principally by neuronal storage leading to progressive mental deterioration. Two guinea pigs with stunted growth, progressive mental dullness, behavioral abnormalities, and abnormal posture and gait, showed a deficiency of acidic alpha-mannosidase activity in leukocytes, plasma, fibroblasts, and whole liver extracts. Fractionation of liver demonstrated a deficiency of lysosomal (acidic) alpha-mannosidase activity. Thin layer chromatography of urine and tissue extracts confirmed the diagnosis by demonstrating a pattern of excreted and stored oligosaccharides almost identical to that of urine from a human alpha-mannosidosis patient. Widespread neuronal vacuolation was observed throughout the CNS, including the cerebral cortex, hippocampus, thalamus, cerebellum, midbrain, pons, medulla, and the dorsal and ventral horns of the spinal cord. Lysosomal vacuolation also occurred in many other visceral tissues and was particularly severe in pancreas, thyroid, epididymis, and peripheral ganglion. Axonal spheroids were observed in some brain regions, but gliosis and demyelination were not observed. Ultrastructurally, most vacuoles in both the CNS and visceral tissues were lucent or contained fine fibrillar or flocculent material. Rare large neurons in the cerebral cortex contained fine membranous structures. Skeletal abnormalities were very mild. Alpha-mannosidosis in the guinea pig closely resembles the human disease and will provide a convenient model for investigation of new therapeutic strategies for neuronal storage diseases, such as enzyme replacement and gene replacement therapies.
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Affiliation(s)
- A C Crawley
- Department of Chemical Pathology, Women's and Children's Hospital, North Adelaide, SA, Australia
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Zervas M, Walkley SU. Ferret pyramidal cell dendritogenesis: changes in morphology and ganglioside expression during cortical development. J Comp Neurol 1999; 413:429-48. [PMID: 10502250 DOI: 10.1002/(sici)1096-9861(19991025)413:3<429::aid-cne6>3.0.co;2-7] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Pyramidal cell ontogenesis and basilar dendritic differentiation were evaluated concomitantly with ganglioside expression and distribution in ferret cerebral cortex. Layer V neurons began basilar dendritogenesis on postnatal day 1 (P1) with a peak in dendritic arborization occurring at P21. Layer II/III neurons, in contrast, were in early stages of basilar dendritic differentiation at P14, resulting in a complex dendritic arbor at P28. High performance thin-layer chromatography showed numerous changes in ganglioside expression during cortical development, including a decline of GM2 in the mature cortex. The temporal expression and cellular distribution of GM2, GD2, GM1, GD3, and GM3 gangliosides in developing cerebral cortex were determined by immunocytochemistry. GM2 immunoreactivity (IR) was most prominent in layer V neurons between P1 and P21 and in layer II/III neurons between P14 and P28 with staining diminishing to near absent levels in the adult. GM2-IR appeared as punctate structures within the somatodendritic domain and by electron microscopy was shown to be membrane-bound vesicles often in close proximity to the plasmalemma. Expression of GM2, but not of other gangliosides studied, followed two well-documented developmental neurogenic gradients: ventrolateral to dorsomedial and radial (inside-first outside-last). Onset of significant GD2 expression in layer II/III and V pyramidal cells was delayed until P14 and persisted in adult neocortex. GD3 was localized most prominently to glial-like cells, whereas GM1 was primarily localized to white matter. The close temporal and spatial concordance of GM2-IR in cortical pyramidal neurons undergoing dendritogenesis is consistent with its proposed role as a modulator of dendritic differentiation.
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Affiliation(s)
- M Zervas
- Sidney Weisner Laboratory of Genetic Neurological Disease, Department of Neuroscience, Rose F. Kennedy Center for Research in Mental Retardation and Human Development, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Walkley SU, Siegel DA, Dobrenis K, Zervas M. GM2 ganglioside as a regulator of pyramidal neuron dendritogenesis. Ann N Y Acad Sci 1998; 845:188-99. [PMID: 9668352 DOI: 10.1111/j.1749-6632.1998.tb09671.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
One of the most profound events in the life of a neuron in the mammalian CNS is the development of a characteristic dendritic tree, yet little is understood about events controlling this process. Pyramidal neurons of the cerebral cortex are known to undergo a single explosive burst of dendritic sprouting immediately after completing migration to the cortical mantle, and following maturation there is no evidence that new, primary dendrites are initiated. Yet in one group of rare genetic diseases--Tay-Sachs disease and related neuronal storage disorders--cortical pyramidal neurons undergo a second period of dendritogenesis. New dendritic membrane is generated principally at the axon hillock and in time is covered with normal-appearing spines and synapses. In our studies of normal brain development and storage diseases we consistently find one feature in common in cortical pyramidal neurons undergoing active dendritogenesis: They exhibit dramatically increased expression of GM2 ganglioside localized to cytoplasmic vacuoles within neuronal perikarya and proximal dendrites. There is also evidence that the increase in GM2 precedes dendritic spouting, and that after dendritic maturation is complete (in normal brain) the GM2 levels in neurons become substantially reduced. These findings are consistent with GM2 ganglioside playing a pivotal role in the regulation of dendritogenesis in cortical pyramidal neurons.
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Affiliation(s)
- S U Walkley
- Sidney Weisner Laboratory of Genetic Neurological Disease, Department of Neuroscience, Rose F. Kennedy Center for Research in Mental Retardation and Human Development, Albert Einstein College of Medicine, Bronx, New York 10461, USA.
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Schwarz A, Futerman AH. Inhibition of sphingolipid synthesis, but not degradation, alters the rate of dendrite growth in cultured hippocampal neurons. BRAIN RESEARCH. DEVELOPMENTAL BRAIN RESEARCH 1998; 108:125-30. [PMID: 9693790 DOI: 10.1016/s0165-3806(98)00041-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Axonal growth can be disrupted by various treatments that inhibit the synthesis of membrane components or their delivery by microtubule-based transport. In cultured hippocampal neurons, a direct correlation exists between the synthesis of sphingolipids, and particularly the simplest glycosphingolipid, glucosylceramide, and the ability of growth factors to stimulate axonal growth [S. Boldin, A.H. Futerman, J. Neurochem. 68 (1997) 882-885]. We now demonstrate that dendritic growth in hippocampal neurons also requires ongoing sphingolipid synthesis. Upon incubation with fumonisin B1 (FB1), an inhibitor of acylation of sphingoid long-chain bases, dendritic growth rates are approximately 25% slower than those of control cells, resulting in neurons with shorter dendritic arbors and less dendritic branch points per cell, and readily apparent differences in morphology compared to control cells after 10-14 days in culture. In contrast, FB1 had no effect on the initial growth of the minor processes, which are destined to become dendrites, even in cells in which FB1 affected the rate of axon growth. Inhibition of sphingolipid degradation, by incubation with conduritol-B-epoxide (an inhibitor of glucosylceramide degradation) had no effect on dendrite or minor process growth at any stage of development, and no aberrant neurite or ectopic dendrite formation was observed. Together, these data demonstrate that normal dendrite growth in hippocampal neurons requires sphingolipid synthesis, although the molecular requirements for sphingolipid synthesis may differ from those in axons.
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Affiliation(s)
- A Schwarz
- Department of Biological Chemistry, Weizmann Institute of Science, Rehovot, Israel
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Abstract
Lysosomal storage disorders are rare, inborn errors of metabolism characterized by intralysosomal accumulation of unmetabolized compounds. The brain is commonly a central focus of the disease process and children and animals affected by these disorders often exhibit progressively severe neurological abnormalities. Although most storage diseases result from loss of activity of a single enzyme responsible for a single catabolic step in a single organelle, the lysosome, the overall features of the resulting disease belies this simple beginning. These are enormously complex disorders with metabolic and functional consequences that go far beyond the lysosome and impact both soma-dendritic and axonal domains of neurons in highly neuron type-specific ways. Cellular pathological changes include growth of ectopic dendrites and new synaptic connections and formation of enlargements in axons far distant from the lysosomal defect. Other storage diseases exhibit neuron death, also occurring in a cell-selective manner. The functional links between known molecular genetic and enzyme defects and changes in neuronal integrity remain largely unknown. Future studies on the biology of lysosomal storage diseases affecting the brain can be anticipated to provide insights not only into these pathogenic mechanisms, but also into the role of lysosomes and related organelles in normal neuron function.
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Affiliation(s)
- S U Walkley
- Department of Neuroscience, Rose F. Kennedy Center for Research in Mental Retardation and Human Development, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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Abstract
A wide variety of inherited lysosomal hydrolase deficiencies have been reported in animals and are characterized by accumulation of sphingolipids, glycolipids, oligosaccharides, or mucopolysaccharides within lysosomes. Inhibitors of a lysosomal hydrolase, e.g., swainsonine, may also induce storage disease. Another group of lysosomal storage diseases, the ceroid-lipofuscinoses, involve the accumulation of hydrophobic proteins, but their pathogenesis is unclear. Some of these diseases are of veterinary importance, and those caused by a hydrolase deficiency can be controlled by detection of heterozygotes through the gene dosage phenomenon or by molecular genetic techniques. Other of these diseases are important to biomedical research either as models of the analogous human disease and/or through their ability to help elucidate specific aspects of cell biology. Some of these models have been used to explore possible therapeutic strategies and to define their limitations and expectations.
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Affiliation(s)
- R D Jolly
- Department of Veterinary Pathology and Public Health, Massey University, Palmerston North, New Zealand
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Brown DE, Thrall MA, Walkley SU, Wurzelmann S, Wenger DA, Allison RW, Just CA. Metabolic abnormalities in feline Niemann-Pick type C heterozygotes. J Inherit Metab Dis 1996; 19:319-30. [PMID: 8803775 DOI: 10.1007/bf01799262] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Niemann-Pick disease type C (NPC) is an autosomal recessive neurovisceral lysosomal storage disorder in which cholesterol lipidosis results from defective intracellular transport of unesterified cholesterol. The primary molecular defect of NPC is unknown; regulatory mechanisms of cholesterol metabolism are impaired, resulting in retarded esterification of exogenous cholesterol with accumulation of unesterified cholesterol in lysosomes and secondary storage of glycolipids and sphingomyelin. In obligate heterozygotes from a feline NPC model, cultured skin fibroblasts challenged with exogenously derived cholesterol exhibited intermediate rates of cholesterol esterification and accumulation of unesterified cholesterol. Liver lipid analyses of obligate heterozygote cats demonstrated intermediate cholesterol and sphingomyelin concentrations. Vacuolated skin fibroblasts were found in 2 of 3 heterozygote cats, and occasional cortical neurons exhibited intracellular inclusions immunoreactive for GM2-ganglioside. Ultrastructural studies provided evidence of storage in liver and brain. We believe these morphological and biochemical findings are the first example of manifestations of CNS abnormalities in a genetic carrier for a neuronal storage disease.
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Affiliation(s)
- D E Brown
- Department of Pathology, Colorado State University, Fort Collins, USA
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Abstract
GM2 ganglioside, although scarce in normal adult brain, is the predominant ganglioside accumulating in several types of lysosomal disorders, most notably Tay-Sachs disease. Pyramidal neurons of cerebral cortex in Tay-Sachs, as well as many other types of neuronal storage disorders, are known to exhibit a phenomenon believed unique to storage disorders: growth of ectopic dendrites. Recent studies have shown that a common metabolic abnormality shared by storage diseases with ectopic dendrite growth is the abnormal accumulation of GM2 ganglioside. The correlation between increased levels of GM2 and the presence of ectopic dendrites has been found in both ganglioside and nonganglioside storage disorders, the latter including sphingomyelin-cholesterol lipidosis, mucopolysaccharidosis, and alpha-mannosidosis. Quantitative HPTLC analysis has shown that increases in GM2 occur in proportion to the incidence of ectopic dendrite growth, whereas other gangliosides, including GM1, lack similar increases. Immunocytochemical studies of all nonganglioside storage diseases which exhibit ectopic dendritogenesis have revealed heightened GM2 ganglioside-immunoreactivity in the cortical pyramidal cell population, whereas nerurons in normal adult brain exhibit little or no staining for this ganglioside. Further, studies examining disease development have consistently shown that accumulation of GM2 ganglioside precedes growth of ectopic dendrites, indicating that it is not simply occurring secondary to new membrane production. These findings have prompted an examination for a similar relationship between GM2 ganglioside and dendritogenesis in cortical neurons of normal developing brain. Results show that GM2 ganglioside-immunoreactivity is consistently elevated in immature neurons during the period when they are undergoing active dendritic initiation, but this staining diminishes dramatically as the dendritic trees of these cells mature. Collectively, these studies on diseased and normal brain offer compelling evidence that GM2 ganglioside plays a pivotal role in the regulation of dendritogenesis in cortical pyramidal neurons.
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Affiliation(s)
- S U Walkley
- Department of Neuroscience, Rose F. Kennedy Center for Research in Mental Retardation and Human Development, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Walkley SU, March PA, Schroeder CE, Wurzelmann S, Jolly RD. Pathogenesis of brain dysfunction in Batten disease. AMERICAN JOURNAL OF MEDICAL GENETICS 1995; 57:196-203. [PMID: 7668330 DOI: 10.1002/ajmg.1320570218] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Animal models of Batten disease and other neuronal storage disorders offer important opportunities to study the pathogenesis of brain dysfunction in this family of diseases. Although all of these conditions exhibit progressive intraneuronal storage, we have found that other aspects of the cellular pathology of Batten disease differ markedly from those of storage disorders caused by lysosomal hydrolase deficiencies. Likewise, lysosomal of cerebral cortex and other select brain regions, a prominent characteristic of Batten disease, does not occur in most other storage disorders. Our studies indicate that Batten disease has findings in common with human neurodegenerative diseases and that neuron death may be caused by excitotoxicity occurring secondary to the combined effects of suboptimal mitochondrial function and GABAergic (inhibitory) cell loss.
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Affiliation(s)
- S U Walkley
- Department of Neuroscience, Rose F. Kennedy Center for Research in Mental Retardation and Human Development, Albert Einstein College of Medicine, Bronx, New York 10461, USA
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Walkley SU, Wurzelmann S. Alterations in synaptic connectivity in cerebral cortex in neuronal storage disorders. ACTA ACUST UNITED AC 1995. [DOI: 10.1002/mrdd.1410010306] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Siegel DA, Walkley SU. Growth of ectopic dendrites on cortical pyramidal neurons in neuronal storage diseases correlates with abnormal accumulation of GM2 ganglioside. J Neurochem 1994; 62:1852-62. [PMID: 8158134 DOI: 10.1046/j.1471-4159.1994.62051852.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Ganglioside analysis and quantitative Golgi studies of the cerebral cortex of cats with ganglioside and nonganglioside lysosomal storage diseases reveal a correlation between the amount of accumulated GM2 ganglioside and the extent of ectopic dendrite growth on cortical pyramidal neurons. This correlation was not observed with any of the other gangliosides assayed for, including GM1 ganglioside. These results suggest a specific role for GM2 ganglioside in the initiation of ectopic neurites on pyramidal cells in vivo and are consistent with the developing hypothesis that different gangliosides have specific roles in different cell types dependent upon the receptor or other effector molecules with which they may interact.
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Affiliation(s)
- D A Siegel
- Department of Neuroscience, Rose F. Kennedy Center for Research in Mental Retardation and Human Development, Albert Einstein College of Medicine, Bronx, New York 10461
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Walkley SU, Thrall MA, Dobrenis K, Huang M, March PA, Siegel DA, Wurzelmann S. Bone marrow transplantation corrects the enzyme defect in neurons of the central nervous system in a lysosomal storage disease. Proc Natl Acad Sci U S A 1994; 91:2970-4. [PMID: 8159689 PMCID: PMC43496 DOI: 10.1073/pnas.91.8.2970] [Citation(s) in RCA: 148] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Neuronal storage disorders are fatal neurodegenerative diseases of humans and animals that are caused by inherited deficiencies of lysosomal hydrolase activity. Affected individuals often appear normal at birth but eventually develop progressive neurologic symptoms including sensory and motor deficits, mental retardation, and seizures. We have examined efficacy of bone marrow transplantation as a means of enzyme replacement, using cats with the lysosomal storage disease alpha-mannosidosis. Treated animals showed little or no progression of neurologic signs 1-2 years after transplant, whereas untreated cats became severely impaired and reached endstage disease by 6 months of age. Increased lysosomal alpha-mannosidase activity was found in brain tissue of the treated animals, and electron microscopy revealed no evidence of lysosomal storage within most neurons. Histochemical localization of acidic alpha-D-mannoside mannohydrolase (EC 3.2. 1.24), using 5-bromo-4-chloro-3-indolyl alpha-D-mannopyranoside, showed that functional enzyme was present in neurons, glial cells, and cells associated with blood vessels. This study provides direct evidence that bone marrow transplantation as treatment for a neuronal storage disease can lead to significant levels of a missing lysosomal hydrolase within neurons of the central nervous system and to compensation for the genetic metabolic defect.
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Affiliation(s)
- S U Walkley
- Department of Neuroscience, Rose F. Kennedy Center for Research in Mental Retardation and Human Development, Albert Einstein College of Medicine, Bronx, NY 10461
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Affiliation(s)
- S U Walkley
- Department of Neuroscience, Rose F. Kennedy Center for Research in Mental Retardation and Human Development, Albert Einstein College of Medicine, Bronx, NY 10461
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