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Xu T, Heon-Roberts R, Moore T, Dubot P, Pan X, Guo T, Cairo CW, Holley R, Bigger B, Durcan TM, Levade T, Ausseil J, Amilhon B, Gorelik A, Nagar B, Sturiale L, Palmigiano A, Röckle I, Thiesler H, Hildebrandt H, Garozzo D, Pshezhetsky AV. Secondary deficiency of neuraminidase 1 contributes to CNS pathology in neurological mucopolysaccharidoses via hypersialylation of brain glycoproteins. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.26.587986. [PMID: 38712143 PMCID: PMC11071461 DOI: 10.1101/2024.04.26.587986] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2024]
Abstract
Mucopolysaccharidoses (MPS) are lysosomal storage diseases caused by defects in catabolism of glycosaminoglycans. MPS I, II, III and VII are associated with lysosomal accumulation of heparan sulphate and manifest with neurological deterioration. Most of these neurological MPS currently lack effective treatments. Here, we report that, compared to controls, neuraminidase 1 (NEU1) activity is drastically reduced in brain tissues of neurological MPS patients and in mouse models of MPS I, II, IIIA, IIIB and IIIC, but not of other neurological lysosomal disorders not presenting with heparan sulphate storage. We further show that accumulated heparan sulphate disrupts the lysosomal multienzyme complex of NEU1 with cathepsin A (CTSA), β-galactosidase (GLB1) and glucosamine-6-sulfate sulfatase (GALNS) necessary to maintain enzyme activity, and that NEU1 deficiency is linked to partial deficiencies of GLB1 and GALNS in cortical tissues and iPSC-derived cortical neurons of neurological MPS patients. Increased sialylation of N-linked glycans in brain samples of human MPS III patients and MPS IIIC mice implicated insufficient processing of brain N-linked sialylated glycans, except for polysialic acid, which was reduced in the brains of MPS IIIC mice. Correction of NEU1 activity in MPS IIIC mice by lentiviral gene transfer ameliorated previously identified hallmarks of the disease, including memory impairment, behavioural traits, and reduced levels of the excitatory synapse markers VGLUT1 and PSD95. Overexpression of NEU1 also restored levels of VGLUT1-/PSD95-positive puncta in cortical neurons derived from iPSC of an MPS IIIA patient. Together, our data demonstrate that heparan sulphate-induced secondary NEU1 deficiency and aberrant sialylation of glycoproteins implicated in synaptogenesis, memory, and behaviour constitute a novel pathological pathway in neurological MPS spectrum crucially contributing to CNS pathology. Graphical abstract
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Deschenes NM, Cheng C, Khanal P, Quinville BM, Ryckman AE, Mitchell M, Pshezhetsky AV, Walia JS. Characterization of a phenotypically severe animal model for human AB-Variant GM2 gangliosidosis. Front Mol Neurosci 2023; 16:1242814. [PMID: 38098938 PMCID: PMC10720325 DOI: 10.3389/fnmol.2023.1242814] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Accepted: 10/23/2023] [Indexed: 12/17/2023] Open
Abstract
AB-Variant GM2 gangliosidosis (ABGM2) is a rare and lethal genetic disorder caused by mutations in the GM2A gene that lead to fatal accumulation of GM2 gangliosides (GM2) in neurons of the central nervous system (CNS). GM2A encodes a transport protein known as GM2 activator (GM2A) protein, which is essential for degrading GM2 into their GM3 form. ABGM2 presents in infantile-, juvenile-, and adult-onset forms; of the three, the infantile-onset is the most prominent, and by far the most severe, as evidenced by high levels of GM2 accumulation, widespread neurodegeneration, and death by the age of 4. Gm2a-/- mice are commonly used as a model of ABGM2. These mice are characterized by phenotypes most representative of predicted adult-onset form of ABGM2, which include moderate GM2 accumulation and mild neurological defects. This mild phenotype has been attributed to compensation by alternative GM2 degradation pathways mediated by sialidase, neuraminidase 3 (NEU3), a pathway that is more prominent in mice than humans. To assess the extent to which NEU3 contributes to GM2 degradation, we generated double knock-out (Gm2a-/-Neu3-/-) mice. Compellingly, these mice present with a clinical phenotype resembling that of a more severe ABGM2, including ataxia, reduced mobility and coordination, weight loss, poor body scores, and lethality by 6-7 months. Furthermore, these phenotypes correlate with a dramatic increase in GM2 accumulation in the CNS compared to levels observed in either Gm2a-/- or Neu3-/- mice. Taken together, these studies, for the first-time, confirm that the mild neurological phenotype of Gm2a-/- mice is due to compensatory activity on GM2 catabolism through an alternate breakdown pathway involving NEU3. These studies support the use of double knockout mice as a novel and highly relevant model for pre-clinical drug studies in a more severe form of ABGM2.
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Affiliation(s)
| | - Camilyn Cheng
- Centre for Neuroscience Studies, Queen’s University, Kingston, ON, Canada
| | - Prem Khanal
- Department of Pediatrics, Queen’s University, Kingston, ON, Canada
| | | | - Alex E. Ryckman
- Centre for Neuroscience Studies, Queen’s University, Kingston, ON, Canada
| | - Melissa Mitchell
- Department of Pediatrics, Queen’s University, Kingston, ON, Canada
| | - Alexey V. Pshezhetsky
- Centre Hospitalier Universitaire Sainte-Justine Research Centre, Department of Pediatrics, University of Montreal, Montreal, QC, Canada
| | - Jagdeep S. Walia
- Centre for Neuroscience Studies, Queen’s University, Kingston, ON, Canada
- Department of Pediatrics, Queen’s University, Kingston, ON, Canada
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Okun S, Peek A, Igdoura SA. Neuraminidase 4 (NEU4): new biological and physiological player. Glycobiology 2023; 33:182-187. [PMID: 36728702 DOI: 10.1093/glycob/cwad008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 12/20/2022] [Accepted: 01/26/2023] [Indexed: 02/03/2023] Open
Abstract
Sialidases are found in viruses, bacteria, fungi, avians, and mammals. Mammalian sialidases differ in their specificity, optimum pH, subcellular localization, and tissue expression. To date, four genes encoding mammalian sialidases (NEU1-4) have been cloned. This review examines the functional impact of NEU4 sialidase on complex physiological and cellular processes. The intracellular localization and trafficking of NEU4 and its potential target molecules are discussed along with its impact on cancer, lysosomal storage disease, and cellular differentiation. Modulation of NEU4 expression may be essential not only for the breakdown of sialylated glycoconjugates, but also in the activation or inactivation of functionally important cellular events.
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Affiliation(s)
- Sarah Okun
- Department of Biology , McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Allyson Peek
- Department of Biology , McMaster University, Hamilton, ON L8S 4K1, Canada
| | - Suleiman A Igdoura
- Department of Biology , McMaster University, Hamilton, ON L8S 4K1, Canada
- Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON L8S 4K1, Canada
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Sialidase neu4 deficiency is associated with neuroinflammation in mice. Glycoconj J 2021; 38:649-667. [PMID: 34686927 DOI: 10.1007/s10719-021-10017-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 07/11/2021] [Accepted: 08/12/2021] [Indexed: 10/20/2022]
Abstract
Sialidases catalyze the removal of sialic acid residues from glycoproteins, oligosaccharides, and sialylated glycolipids. Sialidase Neu4 is in the lysosome and has broad substrate specificity. Previously generated Neu4-/- mice were viable, fertile and lacked gross morphological abnormalities, but displayed a marked vacuolization and lysosomal storage in lung and spleen cells. In addition, we showed that there is an increased level of GD1a ganglioside and a markedly decreased level of GM1 ganglioside in the brain of Neu4-/- mice. In this study, we further explored whether sialidase Neu4 deficiency causes neuroinflammation. We demostrated that elevated level of GD1a and GT1b is associated with an increased level of LAMP1-positive lysosomal vesicles and Tunel-positive neurons correlated with alterations in the expression of cytokines and chemokines in adult Neu4-/- mice. Astrogliosis and microgliosis were also significantly enhanced in the hippocampus, and cerebellum. These changes in brain immunity were accompanied by motor impairment in these mice. Our results indicate that sialidase Neu4 is a novel mediator of an inflammatory response in the mouse brain due to the altered catabolism of gangliosides.
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Head-Only Stunning of Turkeys Part 2: Subjective and Objective Assessment of the Application of AC and DC Waveforms. Animals (Basel) 2021; 11:ani11020286. [PMID: 33498740 PMCID: PMC7912398 DOI: 10.3390/ani11020286] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/13/2021] [Accepted: 01/15/2021] [Indexed: 01/11/2023] Open
Abstract
Simple Summary In this study, we investigated various types of application of head-only electrical stunning to turkeys, in order to improve the effectiveness of the stunning process. We used recordings of physical responses and of electroencephalograms (EEGs) to assess effectivity of stunning and various waveforms: alternating current (AC) and pulsed direct currents (DC). Depending on the waveforms, voltages between 125 and 250 V produced an effective stun in turkeys in this study. Abstract Electrical stunning is likely to remain an important stunning method for turkeys at slaughter. The purpose of this study is to understand the application of various waveforms of alternating current (AC) and pulsed direct currents (DC), head-only, to turkeys and to improve the effectiveness of handheld stunning of turkeys. We evaluated the effectiveness of stunning by documenting physical responses and recording electroencephalograms (EEGs). For the assessment of physical responses, the stunning voltage was varied depending on the proportion of animals effectively stunned at a certain voltage level. If all turkeys in a group of 10 were stunned, the voltage was decreased, and the next group was stunned. This was repeated until not all turkeys showed signs of being effectively stunned. The experiment was then repeated at the voltage level just above the one that showed incomplete effective stunning. The effects of the stunning on the EEG recording was assessed in 16 turkeys to measure the occurrence of epileptiform EEGs, in 14 turkeys to assess epileptiform EEGs after neck-cut (bleeding), and in 14 turkeys to assess the effect of increased voltage and reduced frequency on epileptiform EEGs. Assessing EEGs in a laboratory setting contributes considerably to the understanding of electrical stunning procedures. Voltages between 125 and 250 V, depending on the waveform assessed, were effective in producing an effective stun in turkeys in this study.
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Demir SA, Timur ZK, Ateş N, Martínez LA, Seyrantepe V. GM2 ganglioside accumulation causes neuroinflammation and behavioral alterations in a mouse model of early onset Tay-Sachs disease. J Neuroinflammation 2020; 17:277. [PMID: 32951593 PMCID: PMC7504627 DOI: 10.1186/s12974-020-01947-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Accepted: 09/01/2020] [Indexed: 11/10/2022] Open
Abstract
Background Tay-Sachs disease (TSD), a type of GM2-gangliosidosis, is a progressive neurodegenerative lysosomal storage disorder caused by mutations in the α subunit of the lysosomal β-hexosaminidase enzyme. This disease is characterized by excessive accumulation of GM2 ganglioside, predominantly in the central nervous system. Although Tay-Sachs patients appear normal at birth, the progressive accumulation of undegraded GM2 gangliosides in neurons leads to death. Recently, an early onset Tay-Sachs disease mouse model, with genotype Hexa−/−Neu3−/−, was generated. Progressive accumulation of GM2 led to premature death of the double KO mice. Importantly, this double-deficient mouse model displays typical features of Tay-Sachs patients, such as cytoplasmic vacuolization of nerve cells, deterioration of Purkinje cells, neuronal death, deceleration in movement, ataxia, and tremors. GM2-gangliosidosis is characterized by acute neurodegeneration preceded by activated microglia expansion, macrophage, and astrocyte activation, along with the production of inflammatory mediators. However, the mechanism of disease progression in Hexa−/−Neu3−/− mice, relevant to neuroinflammation is poorly understood. Method In this study, we investigated the onset and progression of neuroinflammatory changes in the cortex, cerebellum, and retina of Hexa−/−Neu3−/− mice and control littermates by using a combination of molecular genetics and immunochemical procedures. Results We found elevated levels of pro-inflammatory cytokine and chemokine transcripts, such as Ccl2, Ccl3, Ccl4, and Cxcl10 and also extensive microglial and astrocyte activation and proliferation, accompanied by peripheral blood mononuclear cell infiltration in the vicinity of neurons and oligodendrocytes. Behavioral tests demonstrated a high level of anxiety, and age-dependent loss in both spatial learning and fear memory in Hexa−/−Neu3−/− mice compared with that in the controls. Conclusion Altogether, our data suggest that Hexa−/−Neu3−/− mice display a phenotype similar to Tay-Sachs patients suffering from chronic neuroinflammation triggered by GM2 accumulation. Furthermore, our work contributes to better understanding of the neuropathology in a mouse model of early onset Tay-Sachs disease.
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Affiliation(s)
- Seçil Akyıldız Demir
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430, Izmir, Turkey
| | - Zehra Kevser Timur
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430, Izmir, Turkey
| | - Nurselin Ateş
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430, Izmir, Turkey
| | - Luis Alarcón Martínez
- Institute of Neurological Science and Psychiatry, Hacettepe University, Sihhiye, 06100, Ankara, Turkey
| | - Volkan Seyrantepe
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430, Izmir, Turkey.
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Substrate Reduction Therapy for Sandhoff Disease through Inhibition of Glucosylceramide Synthase Activity. Mol Ther 2019; 27:1495-1506. [PMID: 31208914 DOI: 10.1016/j.ymthe.2019.05.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Revised: 05/10/2019] [Accepted: 05/19/2019] [Indexed: 12/12/2022] Open
Abstract
Neuronopathic glycosphingolipidoses are a sub-group of lysosomal storage disorders for which there are presently no effective therapies. Here, we evaluated the potential of substrate reduction therapy (SRT) using an inhibitor of glucosylceramide synthase (GCS) to decrease the synthesis of glucosylceramide (GL1) and related glycosphingolipids. The substrates that accumulate in Sandhoff disease (e.g., ganglioside GM2 and its nonacylated derivative, lyso-GM2) are distal to the drug target, GCS. Treatment of Sandhoff mice with a GCS inhibitor that has demonstrated CNS access (Genz-682452) reduced the accumulation of GL1 and GM2, as well as a variety of disease-associated substrates in the liver and brain. Concomitant with these effects was a significant decrease in the expression of CD68 and glycoprotein non-metastatic melanoma B protein (Gpnmb) in the brain, indicating a reduction in microgliosis in the treated mice. Moreover, using in vivo imaging, we showed that the monocytic biomarker translocator protein (TSPO), which was elevated in Sandhoff mice, was normalized following Genz-682452 treatment. These positive effects translated in turn into a delay (∼28 days) in loss of motor function and coordination, as measured by rotarod latency, and a significant increase in longevity (∼17.5%). Together, these results support the development of SRT for the treatment of gangliosidoses, particularly in patients with residual enzyme activity.
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Pshezhetsky AV, Ashmarina M. Keeping it trim: roles of neuraminidases in CNS function. Glycoconj J 2018; 35:375-386. [PMID: 30088207 PMCID: PMC6182584 DOI: 10.1007/s10719-018-9837-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 07/25/2018] [Accepted: 07/27/2018] [Indexed: 12/11/2022]
Abstract
The sialylated glyconjugates (SGC) are found in abundance on the surface of brain cells, where they form a dense array of glycans mediating cell/cell and cell/protein recognition in numerous physiological and pathological processes. Metabolic genetic blocks in processing and catabolism of SGC result in development of severe storage disorders, dominated by CNS involvement including marked neuroinflammation and neurodegeneration, the pathophysiological mechanisms of which are still discussed. SGC patterns in the brain are cell and organelle-specific, dynamic and maintained by highly coordinated processes of their biosynthesis, trafficking, processing and catabolism. The changes in the composition of SGC during development and aging of the brain cannot be explained based solely on the regulation of the SGC-synthesizing enzymes, sialyltransferases, suggesting that neuraminidases (sialidases) hydrolysing the removal of terminal sialic acid residues also play an essential role. In the current review we summarize the roles of three mammalian neuraminidases: neuraminidase 1, neuraminidase 3 and neuraminidase 4 in processing brain SGC. Emerging data demonstrate that these enzymes with different, yet overlapping expression patterns, intracellular localization and substrate specificity play essential roles in the physiology of the CNS.
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Affiliation(s)
- Alexey V Pshezhetsky
- Sainte-Justine Hospital Research Center, Department of Paediatrics, University of Montreal, CHU Ste-Justine, Centre de recherche, 3175 Côte-Sainte-Catherine, Montréal, Québec, H3T 1C5, Canada.
- Department of Anatomy and Cell Biology, McGill University, Montreal, H3A0C7, Canada.
| | - Mila Ashmarina
- Sainte-Justine Hospital Research Center, Department of Paediatrics, University of Montreal, CHU Ste-Justine, Centre de recherche, 3175 Côte-Sainte-Catherine, Montréal, Québec, H3T 1C5, Canada
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Biological and Pathological Roles of Ganglioside Sialidases. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2018; 156:121-150. [DOI: 10.1016/bs.pmbts.2017.12.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
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Seyrantepe V, Demir SA, Timur ZK, Von Gerichten J, Marsching C, Erdemli E, Oztas E, Takahashi K, Yamaguchi K, Ates N, Dönmez Demir B, Dalkara T, Erich K, Hopf C, Sandhoff R, Miyagi T. Murine Sialidase Neu3 facilitates GM2 degradation and bypass in mouse model of Tay-Sachs disease. Exp Neurol 2017; 299:26-41. [PMID: 28974375 DOI: 10.1016/j.expneurol.2017.09.012] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Revised: 09/14/2017] [Accepted: 09/28/2017] [Indexed: 12/29/2022]
Abstract
Tay-Sachs disease is a severe lysosomal storage disorder caused by mutations in Hexa, the gene that encodes for the α subunit of lysosomal β-hexosaminidase A (HEXA), which converts GM2 to GM3 ganglioside. Unexpectedly, Hexa-/- mice have a normal lifespan and show no obvious neurological impairment until at least one year of age. These mice catabolize stored GM2 ganglioside using sialidase(s) to remove sialic acid and form the glycolipid GA2, which is further processed by β-hexosaminidase B. Therefore, the presence of the sialidase (s) allows the consequences of the Hexa defect to be bypassed. To determine if the sialidase NEU3 contributes to GM2 ganglioside degradation, we generated a mouse model with combined deficiencies of HEXA and NEU3. The Hexa-/-Neu3-/- mice were healthy at birth, but died at 1.5 to 4.5months of age. Thin-layer chromatography and mass spectrometric analysis of the brains of Hexa-/-Neu3-/- mice revealed the abnormal accumulation of GM2 ganglioside. Histological and immunohistochemical analysis demonstrated cytoplasmic vacuolation in the neurons. Electron microscopic examination of the brain, kidneys and testes revealed pleomorphic inclusions of many small vesicles and complex lamellar structures. The Hexa-/-Neu3-/- mice exhibited progressive neurodegeneration with neuronal loss, Purkinje cell depletion, and astrogliosis. Slow movement, ataxia, and tremors were the prominent neurological abnormalities observed in these mice. Furthermore, radiographs revealed abnormalities in the skeletal bones of the Hexa-/-Neu3-/- mice. Thus, the Hexa-/-Neu3-/- mice mimic the neuropathological and clinical abnormalities of the classical early-onset Tay-Sachs patients, and provide a suitable model for the future pre-clinical testing of potential treatments for this condition.
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Affiliation(s)
- Volkan Seyrantepe
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430 Izmir, Turkey.
| | - Secil Akyildiz Demir
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430 Izmir, Turkey
| | - Zehra Kevser Timur
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430 Izmir, Turkey
| | - Johanna Von Gerichten
- Lipid Pathobiochemistry Group (G131) German Cancer Research Center, INF 280, 69120 Heidelberg, Germany
| | - Christian Marsching
- Lipid Pathobiochemistry Group (G131) German Cancer Research Center, INF 280, 69120 Heidelberg, Germany; Center for Applied Research in Applied Biomedical Mass Spectrometry (ABIMAS), Mannheim, Germany; Institute of Medical Technology (IMT) of Heidelberg University and Mannheim University of Applied Sciences, Paul-Wittsach-Str.10, 68163 Mannheim, Germany
| | - Esra Erdemli
- Departments of Histology and Embryology, Ankara University, Medical School, 06100, Sihhiye, Ankara, Turkey
| | - Emin Oztas
- Departments of Histology and Embryology, GATA Medical School, 06100 Ankara, Turkey
| | - Kohta Takahashi
- Cell Recognition Study, Tohoku Pharmaceutical University, Sendai, Japan
| | | | - Nurselin Ates
- Department of Molecular Biology and Genetics, Izmir Institute of Technology, 35430 Izmir, Turkey
| | - Buket Dönmez Demir
- Institutes of Neurological Science and Psychiatry, University of Hacettepe, 06100 Ankara, Turkey
| | - Turgay Dalkara
- Institutes of Neurological Science and Psychiatry, University of Hacettepe, 06100 Ankara, Turkey
| | - Katrin Erich
- Center for Applied Research in Applied Biomedical Mass Spectrometry (ABIMAS), Mannheim, Germany; Institute of Medical Technology (IMT) of Heidelberg University and Mannheim University of Applied Sciences, Paul-Wittsach-Str.10, 68163 Mannheim, Germany
| | - Carsten Hopf
- Center for Applied Research in Applied Biomedical Mass Spectrometry (ABIMAS), Mannheim, Germany; Institute of Medical Technology (IMT) of Heidelberg University and Mannheim University of Applied Sciences, Paul-Wittsach-Str.10, 68163 Mannheim, Germany
| | - Roger Sandhoff
- Lipid Pathobiochemistry Group (G131) German Cancer Research Center, INF 280, 69120 Heidelberg, Germany
| | - Taeko Miyagi
- Miyagi Cancer Center Research Institute, Natori, Japan
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Karumuthil-Melethil S, Nagabhushan Kalburgi S, Thompson P, Tropak M, Kaytor MD, Keimel JG, Mark BL, Mahuran D, Walia JS, Gray SJ. Novel Vector Design and Hexosaminidase Variant Enabling Self-Complementary Adeno-Associated Virus for the Treatment of Tay-Sachs Disease. Hum Gene Ther 2017; 27:509-21. [PMID: 27197548 DOI: 10.1089/hum.2016.013] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
GM2 gangliosidosis is a family of three genetic neurodegenerative disorders caused by the accumulation of GM2 ganglioside (GM2) in neuronal tissue. Two of these are due to the deficiency of the heterodimeric (α-β), "A" isoenzyme of lysosomal β-hexosaminidase (HexA). Mutations in the α-subunit (encoded by HEXA) lead to Tay-Sachs disease (TSD), whereas mutations in the β-subunit (encoded by HEXB) lead to Sandhoff disease (SD). The third form results from a deficiency of the GM2 activator protein (GM2AP), a substrate-specific cofactor for HexA. In their infantile, acute forms, these diseases rapidly progress with mental and psychomotor deterioration resulting in death by approximately 4 years of age. After gene transfer that overexpresses one of the deficient subunits, the amount of HexA heterodimer formed would empirically be limited by the availability of the other endogenous Hex subunit. The present study used a new variant of the human HexA α-subunit, μ, incorporating critical sequences from the β-subunit that produce a stable homodimer (HexM) and promote functional interactions with the GM2AP- GM2 complex. We report the design of a compact adeno-associated viral (AAV) genome using a synthetic promoter-intron combination to allow self-complementary (sc) packaging of the HEXM gene. Also, a previously published capsid mutant, AAV9.47, was used to deliver the gene to brain and spinal cord while having restricted biodistribution to the liver. The novel capsid and cassette design combination was characterized in vivo in TSD mice for its ability to efficiently transduce cells in the central nervous system when delivered intravenously in both adult and neonatal mice. This study demonstrates that the modified HexM is capable of degrading long-standing GM2 storage in mice, and it further demonstrates the potential of this novel scAAV vector design to facilitate widespread distribution of the HEXM gene or potentially other similar-sized genes to the nervous system.
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Affiliation(s)
| | | | - Patrick Thompson
- 2 Medical Genetics/Departments of Pediatrics, Queen's University , Kingston, Ontario, Canada
| | - Michael Tropak
- 3 Genetics and Genome Biology, SickKids, Toronto, Ontario, Canada
| | | | - John G Keimel
- 4 New Hope Research Foundation , North Oaks, Minnesota
| | - Brian L Mark
- 5 Department of Microbiology, University of Manitoba , Winnipeg, Manitoba, Canada
| | - Don Mahuran
- 3 Genetics and Genome Biology, SickKids, Toronto, Ontario, Canada .,6 Department of Laboratory Medicine and Pathology, University of Toronto, Toronto, Ontario, Canada
| | - Jagdeep S Walia
- 2 Medical Genetics/Departments of Pediatrics, Queen's University , Kingston, Ontario, Canada
| | - Steven J Gray
- 1 Gene Therapy Center, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina.,7 Department of Ophthalmology, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina
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Pan X, De Aragão CDBP, Velasco-Martin JP, Priestman DA, Wu HY, Takahashi K, Yamaguchi K, Sturiale L, Garozzo D, Platt FM, Lamarche-Vane N, Morales CR, Miyagi T, Pshezhetsky AV. Neuraminidases 3 and 4 regulate neuronal function by catabolizing brain gangliosides. FASEB J 2017; 31:3467-3483. [PMID: 28442549 DOI: 10.1096/fj.201601299r] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Accepted: 04/11/2017] [Indexed: 11/11/2022]
Abstract
Gangliosides (sialylated glycolipids) play an essential role in the CNS by regulating recognition and signaling in neurons. Metabolic blocks in processing and catabolism of gangliosides result in the development of severe neurologic disorders, including gangliosidoses manifesting with neurodegeneration and neuroinflammation. We demonstrate that 2 mammalian enzymes, neuraminidases 3 and 4, play important roles in catabolic processing of brain gangliosides by cleaving terminal sialic acid residues in their glycan chains. In neuraminidase 3 and 4 double-knockout mice, GM3 ganglioside is stored in microglia, vascular pericytes, and neurons, causing micro- and astrogliosis, neuroinflammation, accumulation of lipofuscin bodies, and memory loss, whereas their cortical and hippocampal neurons have lower rate of neuritogenesis in vitro Double-knockout mice also have reduced levels of GM1 ganglioside and myelin in neuronal axons. Furthermore, neuraminidase 3 deficiency drastically increased storage of GM2 in the brain tissues of an asymptomatic mouse model of Tay-Sachs disease, a severe human gangliosidosis, indicating that this enzyme is responsible for the metabolic bypass of β-hexosaminidase A deficiency. Together, our results provide the first in vivo evidence that neuraminidases 3 and 4 have important roles in CNS function by catabolizing gangliosides and preventing their storage in lipofuscin bodies.-Pan, X., De Britto Pará De Aragão, C., Velasco-Martin, J. P., Priestman, D. A., Wu, H. Y., Takahashi, K., Yamaguchi, K., Sturiale, L., Garozzo, D., Platt, F. M., Lamarche-Vane, N., Morales, C. R., Miyagi, T., Pshezhetsky, A. V. Neuraminidases 3 and 4 regulate neuronal function by catabolizing brain gangliosides.
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Affiliation(s)
- Xuefang Pan
- Sainte-Justine University Hospital Research Center, University of Montreal, Montreal, Quebec, Canada
| | - Camila De Britto Pará De Aragão
- Sainte-Justine University Hospital Research Center, University of Montreal, Montreal, Quebec, Canada.,Department of Anatomy and Cell Biology, Research Institute of the McGill University Health Center, McGill University, Montreal, Quebec, Canada
| | | | - David A Priestman
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Harry Y Wu
- Sainte-Justine University Hospital Research Center, University of Montreal, Montreal, Quebec, Canada
| | - Kohta Takahashi
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Pharmaceutical University, Sendai, Japan
| | | | - Luisella Sturiale
- Consiglio Nazionale delle Ricerche, Institute for Polymers, Composites, and Biomaterials, Catania, Italy
| | - Domenico Garozzo
- Consiglio Nazionale delle Ricerche, Institute for Polymers, Composites, and Biomaterials, Catania, Italy
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford, United Kingdom
| | - Nathalie Lamarche-Vane
- Department of Anatomy and Cell Biology, Research Institute of the McGill University Health Center, McGill University, Montreal, Quebec, Canada
| | - Carlos R Morales
- Department of Anatomy and Cell Biology, Research Institute of the McGill University Health Center, McGill University, Montreal, Quebec, Canada
| | - Taeko Miyagi
- Miyagi Cancer Center Research Institute, Natori, Japan
| | - Alexey V Pshezhetsky
- Sainte-Justine University Hospital Research Center, University of Montreal, Montreal, Quebec, Canada; .,Department of Anatomy and Cell Biology, Research Institute of the McGill University Health Center, McGill University, Montreal, Quebec, Canada
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13
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Mice with Catalytically Inactive Cathepsin A Display Neurobehavioral Alterations. Behav Neurol 2017; 2017:4261873. [PMID: 28133419 PMCID: PMC5241486 DOI: 10.1155/2017/4261873] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2016] [Accepted: 12/05/2016] [Indexed: 11/18/2022] Open
Abstract
The lysosomal carboxypeptidase A, Cathepsin A (CathA), is a serine protease with two distinct functions. CathA protects β-galactosidase and sialidase Neu1 against proteolytic degradation by forming a multienzyme complex and activates sialidase Neu1. CathA deficiency causes the lysosomal storage disease, galactosialidosis. These patients present with a broad range of clinical phenotypes, including growth retardation, and neurological deterioration along with the accumulation of the vasoactive peptide, endothelin-1, in the brain. Previous in vitro studies have shown that CathA has specific activity against vasoactive peptides and neuropeptides, including endothelin-1 and oxytocin. A mutant mouse with catalytically inactive CathA enzyme (CathAS190A) shows increased levels of endothelin-1. In the present study, we elucidated the involvement of CathA in learning and long-term memory in 3-, 6-, and 12-month-old mice. Hippocampal endothelin-1 and oxytocin accumulated in CathAS190A mice, which showed learning impairments as well as long-term and spatial memory deficits compared with wild-type littermates, suggesting that CathA plays a significant role in learning and in memory consolidation through its regulatory role in vasoactive peptide processing.
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14
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Construction of a hybrid β-hexosaminidase subunit capable of forming stable homodimers that hydrolyze GM2 ganglioside in vivo. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2016; 3:15057. [PMID: 26966698 PMCID: PMC4774620 DOI: 10.1038/mtm.2015.57] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 12/17/2015] [Indexed: 02/07/2023]
Abstract
Tay-Sachs or Sandhoff disease result from mutations in either the evolutionarily related HEXA or HEXB genes encoding respectively, the α- or β-subunits of β-hexosaminidase A (HexA). Of the three Hex isozymes, only HexA can interact with its cofactor, the GM2 activator protein (GM2AP), and hydrolyze GM2 ganglioside. A major impediment to establishing gene or enzyme replacement therapy based on HexA is the need to synthesize both subunits. Thus, we combined the critical features of both α- and β-subunits into a single hybrid µ-subunit that contains the α-subunit active site, the stable β-subunit interface and unique areas in each subunit needed to interact with GM2AP. To facilitate intracellular analysis and the purification of the µ-homodimer (HexM), CRISPR-based genome editing was used to disrupt the HEXA and HEXB genes in a Human Embryonic Kidney 293 cell line stably expressing the µ-subunit. In association with GM2AP, HexM was shown to hydrolyze a fluorescent GM2 ganglioside derivative both in cellulo and in vitro. Gene transfer studies in both Tay-Sachs and Sandhoff mouse models demonstrated that HexM expression reduced brain GM2 ganglioside levels.
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15
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Timur ZK, Akyildiz Demir S, Marsching C, Sandhoff R, Seyrantepe V. Neuraminidase-1 contributes significantly to the degradation of neuronal B-series gangliosides but not to the bypass of the catabolic block in Tay-Sachs mouse models. Mol Genet Metab Rep 2015; 4:72-82. [PMID: 26937414 PMCID: PMC4750590 DOI: 10.1016/j.ymgmr.2015.07.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2015] [Revised: 07/23/2015] [Accepted: 07/23/2015] [Indexed: 11/17/2022] Open
Affiliation(s)
- Z K Timur
- Izmir Institute of Technology, Department of Molecular Biology and Genetics, Izmir, Turkey
| | - S Akyildiz Demir
- Izmir Institute of Technology, Department of Molecular Biology and Genetics, Izmir, Turkey
| | - C Marsching
- Lipid Biochemistry Lab, Cancer Research Center, Heidelberg, Germany
| | - R Sandhoff
- Lipid Biochemistry Lab, Cancer Research Center, Heidelberg, Germany
| | - V Seyrantepe
- Izmir Institute of Technology, Department of Molecular Biology and Genetics, Izmir, Turkey
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16
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Martins C, Hůlková H, Dridi L, Dormoy-Raclet V, Grigoryeva L, Choi Y, Langford-Smith A, Wilkinson FL, Ohmi K, DiCristo G, Hamel E, Ausseil J, Cheillan D, Moreau A, Svobodová E, Hájková Z, Tesařová M, Hansíková H, Bigger BW, Hrebícek M, Pshezhetsky AV. Neuroinflammation, mitochondrial defects and neurodegeneration in mucopolysaccharidosis III type C mouse model. ACTA ACUST UNITED AC 2015; 138:336-55. [PMID: 25567323 DOI: 10.1093/brain/awu355] [Citation(s) in RCA: 100] [Impact Index Per Article: 11.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Severe progressive neurological paediatric disease mucopolysaccharidosis III type C is caused by mutations in the HGSNAT gene leading to deficiency of acetyl-CoA: α-glucosaminide N-acetyltransferase involved in the lysosomal catabolism of heparan sulphate. To understand the pathophysiology of the disease we generated a mouse model of mucopolysaccharidosis III type C by germline inactivation of the Hgsnat gene. At 6-8 months mice showed hyperactivity, and reduced anxiety. Cognitive memory decline was detected at 10 months and at 12-13 months mice showed signs of unbalanced hesitant walk and urinary retention. Lysosomal accumulation of heparan sulphate was observed in hepatocytes, splenic sinus endothelium, cerebral microglia, liver Kupffer cells, fibroblasts and pericytes. Starting from 5 months, brain neurons showed enlarged, structurally abnormal mitochondria, impaired mitochondrial energy metabolism, and storage of densely packed autofluorescent material, gangliosides, lysozyme, phosphorylated tau, and amyloid-β. Taken together, our data demonstrate for the first time that deficiency of acetyl-CoA: α-glucosaminide N-acetyltransferase causes lysosomal accumulation of heparan sulphate in microglial cells followed by their activation and cytokine release. They also show mitochondrial dysfunction in the neurons and neuronal loss explaining why mucopolysaccharidosis III type C manifests primarily as a neurodegenerative disease.
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Affiliation(s)
- Carla Martins
- 1 CHU Ste-Justine, University of Montreal, Montreal, QC, Canada
| | - Helena Hůlková
- 2 Institute of Inherited Metabolic Disorders, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czech Republic
| | - Larbi Dridi
- 1 CHU Ste-Justine, University of Montreal, Montreal, QC, Canada
| | | | | | - Yoo Choi
- 1 CHU Ste-Justine, University of Montreal, Montreal, QC, Canada
| | | | - Fiona L Wilkinson
- 3 Stem Cell and Neurotherapies, University of Manchester, Manchester, UK
| | - Kazuhiro Ohmi
- 4 Department of Biological Chemistry, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California, USA
| | | | - Edith Hamel
- 5 Montreal Neurological Institute, McGill University, Montréal, QC, Canada
| | - Jerôme Ausseil
- 6 CHU Amiens, and Unité INSERM U1088, UFR de Médecine, Université de Picardie-Jules Verne, Amiens, France
| | - David Cheillan
- 7 Service des Maladies Héréditaires du Métabolisme et Dépistage Néonatal - Centre de Biologie Est, Hospices Civils de Lyon, Bron, France
| | - Alain Moreau
- 1 CHU Ste-Justine, University of Montreal, Montreal, QC, Canada
| | - Eva Svobodová
- 2 Institute of Inherited Metabolic Disorders, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czech Republic
| | - Zuzana Hájková
- 8 Department of Paediatrics, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czech Republic
| | - Markéta Tesařová
- 8 Department of Paediatrics, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czech Republic
| | - Hana Hansíková
- 8 Department of Paediatrics, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czech Republic
| | - Brian W Bigger
- 3 Stem Cell and Neurotherapies, University of Manchester, Manchester, UK
| | - Martin Hrebícek
- 2 Institute of Inherited Metabolic Disorders, First Faculty of Medicine and General University Hospital in Prague, Charles University, Prague, Czech Republic
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17
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Srimontri P, Endo S, Sakamoto T, Nakayama Y, Kurosaka A, Itohara S, Hirabayashi Y, Kato K. Sialyltransferase ST3Gal IV deletion protects against temporal lobe epilepsy. J Neurochem 2014; 131:675-87. [PMID: 25066807 DOI: 10.1111/jnc.12838] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 07/23/2014] [Accepted: 07/23/2014] [Indexed: 11/27/2022]
Abstract
Temporal lobe epilepsy (TLE) often becomes refractory, and patients with TLE show a high incidence of psychiatric symptoms, including anxiety and depression. Therefore, it is necessary to identify molecules that were previously unknown to contribute to epilepsy and its associated disorders. We previously found that the sialyltransferase ST3Gal IV is up-regulated within the neural circuits through which amygdala-kindling stimulation propagates epileptic seizures. In contrast, this study demonstrated that kindling stimulation failed to evoke epileptic seizures in ST3Gal IV-deficient mice. Furthermore, approximately 80% of these mice failed to show tonic-clonic seizures with stimulation, whereas all littermate wild-type mice showed tonic-clonic seizures. This indicates that the loss of ST3Gal IV does not cause TLE in mice. Meanwhile, ST3Gal IV-deficient mice exhibited decreased acclimation in the open field test, increased immobility in the forced swim test, enhanced freezing during delay auditory fear conditioning, and sleep disturbances. Thus, the loss of ST3Gal IV modulates anxiety-related behaviors. These findings indicate that ST3Gal IV is a key molecule in the mechanisms underlying anxiety - a side effect of TLE - and may therefore also be an effective target for treating epilepsy, acting through the same circuits.
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Affiliation(s)
- Paitoon Srimontri
- Faculty of Life Sciences, Kyoto Sangyo University, Motoyama, Kamigamo, Kita-ku, Kyoto, Japan
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18
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Aureli M, Samarani M, Loberto N, Bassi R, Murdica V, Prioni S, Prinetti A, Sonnino S. The Glycosphingolipid Hydrolases in the Central Nervous System. Mol Neurobiol 2013; 50:76-87. [DOI: 10.1007/s12035-013-8592-6] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Accepted: 11/08/2013] [Indexed: 12/27/2022]
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19
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Albohy A, Zhang Y, Smutova V, Pshezhetsky AV, Cairo CW. Identification of Selective Nanomolar Inhibitors of the Human Neuraminidase, NEU4. ACS Med Chem Lett 2013; 4:532-7. [PMID: 24900705 DOI: 10.1021/ml400080t] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Accepted: 04/26/2013] [Indexed: 12/31/2022] Open
Abstract
The human neuraminidase enzymes (hNEU) play important roles in human physiology and pathology. The lack of potent and selective inhibitors toward these enzymes has limited our understanding of their function and the development of therapeutic applications. Here we report the evaluation of a panel of compounds against the four human neuraminidase isoenzymes. Among the compounds tested, we identified the first selective, nanomolar inhibitors of the human neuraminidase 4 enzyme (NEU4). The most potent NEU4 inhibitor (5-acetamido-9-[4-hydroxymethyl[1,2,3]triazol-1-yl]-2,3,5,9-tetradeoxy-d-glycero-d-galacto-2-nonulopyranosonic acid) was found to have an inhibitory constant (K i ) of 30 ± 19 nM and was 500-fold selective for its target over the other hNEU isoenzymes tested in vitro (NEU1, NEU2, and NEU3). This is the first report of any inhibitor of hNEU with nanomolar potency, and this confirms that the 2,3-didehydro-2-deoxy-N-acetylneuraminic acid (DANA) scaffold can be exploited to develop new, potent, and selective inhibitors that target this important family of human enzymes.
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Affiliation(s)
- Amgad Albohy
- Alberta Glycomics
Center, Department
of Chemistry, University of Alberta, Edmonton
Alberta T6G 2G2, Canada
| | - Yi Zhang
- Alberta Glycomics
Center, Department
of Chemistry, University of Alberta, Edmonton
Alberta T6G 2G2, Canada
| | - Victoria Smutova
- Division of Medical Genetics,
Centre Hospitaliere Universitaire Sainte-Justine, University of Montreal, Montreal, Quebec, Canada, and Department
of Anatomy and Cell Biology, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Alexey V. Pshezhetsky
- Division of Medical Genetics,
Centre Hospitaliere Universitaire Sainte-Justine, University of Montreal, Montreal, Quebec, Canada, and Department
of Anatomy and Cell Biology, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | - Christopher W. Cairo
- Alberta Glycomics
Center, Department
of Chemistry, University of Alberta, Edmonton
Alberta T6G 2G2, Canada
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20
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Takahashi K, Mitoma J, Hosono M, Shiozaki K, Sato C, Yamaguchi K, Kitajima K, Higashi H, Nitta K, Shima H, Miyagi T. Sialidase NEU4 hydrolyzes polysialic acids of neural cell adhesion molecules and negatively regulates neurite formation by hippocampal neurons. J Biol Chem 2012; 287:14816-26. [PMID: 22393058 DOI: 10.1074/jbc.m111.324186] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Modulation of levels of polysialic acid (polySia), a sialic acid polymer, predominantly associated with the neural cell adhesion molecule (NCAM), influences neural functions, including synaptic plasticity, neurite growth, and cell migration. Biosynthesis of polySia depends on two polysialyltransferases ST8SiaII and ST8SiaIV in vertebrate. However, the enzyme involved in degradation of polySia in its physiological turnover remains uncertain. In the present study, we identified and characterized a murine sialidase NEU4 that catalytically degrades polySia. Murine NEU4, dominantly expressed in the brain, was found to efficiently hydrolyze oligoSia and polySia chains as substrates in sialidase in vitro assays, and also NCAM-Fc chimera as well as endogenous NCAM in tissue homogenates of postnatal mouse brain as assessed by immunoblotting with anti-polySia antibodies. Degradation of polySia by NEU4 was also evident in neuroblastoma Neuro2a cells that were co-transfected with Neu4 and ST8SiaIV genes. Furthermore, in mouse embryonic hippocampal primary neurons, the endogenously expressed NEU4 was found to decrease during the neuronal differentiation. Interestingly, GFP- or FLAG-tagged NEU4 was partially co-localized with polySia in neurites and significantly suppressed their outgrowth, whereas silencing of NEU4 showed the acceleration together with an increase in polySia expression. These results suggest that NEU4 is involved in regulation of neuronal function by polySia degradation in mammals.
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Affiliation(s)
- Kohta Takahashi
- Division of Cancer Glycosylation Research, Institute of Molecular Biomembrane and Glycobiology, Tohoku Pharmaceutical University, Sendai, 981-8558, Japan
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21
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Miyagi T, Yamaguchi K. Mammalian sialidases: physiological and pathological roles in cellular functions. Glycobiology 2012; 22:880-96. [PMID: 22377912 DOI: 10.1093/glycob/cws057] [Citation(s) in RCA: 269] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Sialic acids are terminal acidic monosaccharides, which influence the chemical and biological features of glycoconjugates. Their removal catalyzed by a sialidase modulates various biological processes through change in conformation and creation or loss of binding sites of functional molecules. Sialidases exist widely in vertebrates and also in a variety of microorganisms. Recent research on mammalian sialidases has provided evidence for great importance of these enzymes in various cellular functions, including lysosomal catabolism, whereas microbial sialidases appear to play roles limited to nutrition and pathogenesis. Four types of mammalian sialidases have been identified and characterized to date, designated as NEU1, NEU2, NEU3 and NEU4. They are encoded by different genes and differ in major subcellular localization and enzymatic properties including substrate specificity, and each has been found to play a unique role depending on its particular properties. This review is an attempt to concisely summarize current knowledge concerning mammalian sialidases, with a special focus on their properties and physiological and pathological roles in cellular functions.
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Affiliation(s)
- Taeko Miyagi
- Institute of Molecular Biomembrane and Glycobiology, Tohoku Pharmaceutical University, Sendai, Japan.
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22
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Abstract
The removal of sialic acids, catalyzed by sialidase, is the initial step in degradation of oligosaccharides, glycoproteins, and glycolipids. The catalytic reaction may greatly influence biological processes through changing the conformation of glycoproteins and create or mask binding sites of functional molecules. Recent progress in sialidase research has clarified that mammalian sialidases indeed contribute to the regulation of various cellular functions as well as lysosomal catabolism, unlike the sialidases of microbial origin that probably play roles limited to nutrition and pathogenesis. However, the mammalian enzymes contain consensus sequences in the six-blade β-propeller structural organization typical of microbial sialidases, despite the low degree of similarity to the amino acid sequences of the microbial enzymes. The present review briefly summarizes structural and functional features of mammalian sialidases.
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Affiliation(s)
- Eugenio Monti
- Faculty of Medicine, Department of Biomedical Sciences and Biotechnology, University of Brescia, Brescia, Viale Europa 11, 25123, Brescia, Italy
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