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Navratna V, Kumar A, Rana JK, Mosalaganti S. Structure of the human heparan-α-glucosaminide N-acetyltransferase (HGSNAT). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.10.23.563672. [PMID: 37961489 PMCID: PMC10634761 DOI: 10.1101/2023.10.23.563672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Degradation of heparan sulfate (HS), a glycosaminoglycan (GAG) comprised of repeating units of N-acetylglucosamine and glucuronic acid, begins in the cytosol and is completed in the lysosomes. Acetylation of the terminal non-reducing amino group of a-D-glucosamine of HS is essential for its complete breakdown into monosaccharides and free sulfate. Heparan-a-glucosaminide N-acetyltransferase (HGSNAT), a resident of the lysosomal membrane, catalyzes this essential acetylation reaction by accepting and transferring the acetyl group from cytosolic acetyl-CoA to terminal a-D-glucosamine of HS in the lysosomal lumen. Mutation-induced dysfunction in HGSNAT causes abnormal accumulation of HS within the lysosomes and leads to an autosomal recessive neurodegenerative lysosomal storage disorder called mucopolysaccharidosis IIIC (MPS IIIC). There are no approved drugs or treatment strategies to cure or manage the symptoms of, MPS IIIC. Here, we use cryo-electron microscopy (cryo-EM) to determine a high-resolution structure of the HGSNAT-acetyl-CoA complex, the first step in HGSNAT catalyzed acetyltransferase reaction. In addition, we map the known MPS IIIC mutations onto the structure and elucidate the molecular basis for mutation-induced HGSNAT dysfunction.
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Affiliation(s)
- Vikas Navratna
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109, United States
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, 48109, United States
| | - Arvind Kumar
- Thermo Fisher Scientific, Waltham, Massachusetts, 02451, United States
| | - Jaimin K. Rana
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109, United States
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, 48109, United States
| | - Shyamal Mosalaganti
- Life Sciences Institute, University of Michigan, Ann Arbor, Michigan, 48109, United States
- Department of Cell and Developmental Biology, University of Michigan, Ann Arbor, Michigan, 48109, United States
- Department of Biophysics, College of Literature, Science and the Arts, University of Michigan, Ann Arbor, Michigan, 48109, United States
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Xu R, Ning Y, Ren F, Gu C, Zhu Z, Pan X, Pshezhetsky AV, Ge J, Yu J. Structure and mechanism of lysosome transmembrane acetylation by HGSNAT. Nat Struct Mol Biol 2024:10.1038/s41594-024-01315-5. [PMID: 38769387 DOI: 10.1038/s41594-024-01315-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2023] [Accepted: 04/11/2024] [Indexed: 05/22/2024]
Abstract
Lysosomal transmembrane acetylation of heparan sulfates (HS) is catalyzed by HS acetyl-CoA:α-glucosaminide N-acetyltransferase (HGSNAT), whose dysfunction leads to lysosomal storage diseases. The mechanism by which HGSNAT, the sole non-hydrolase enzyme in HS degradation, brings cytosolic acetyl-coenzyme A (Ac-CoA) and lysosomal HS together for N-acyltransferase reactions remains unclear. Here, we present cryogenic-electron microscopy structures of HGSNAT alone, complexed with Ac-CoA and with acetylated products. These structures explain that Ac-CoA binding from the cytosolic side causes dimeric HGSNAT to form a transmembrane tunnel. Within this tunnel, catalytic histidine and asparagine approach the lumen and instigate the transfer of the acetyl group from Ac-CoA to the glucosamine group of HS. Our study unveils a transmembrane acetylation mechanism that may help advance therapeutic strategies targeting lysosomal storage diseases.
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Affiliation(s)
- Ruisheng Xu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Yingjie Ning
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Fandong Ren
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China
| | - Chenxia Gu
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Zhengjiang Zhu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China
| | - Xuefang Pan
- Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine Research Centre, University of Montreal, Montreal, Quebec, Canada
| | - Alexey V Pshezhetsky
- Department of Pediatrics, Centre Hospitalier Universitaire Sainte-Justine Research Centre, University of Montreal, Montreal, Quebec, Canada.
- Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada.
| | - Jingpeng Ge
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China.
| | - Jie Yu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, China.
- Shanghai Key Laboratory of Aging Studies, Shanghai, China.
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Pan X, Caillon A, Fan S, Khan S, Tomatsu S, Pshezhetsky AV. Heterologous HSPC Transplantation Rescues Neuroinflammation and Ameliorates Peripheral Manifestations in the Mouse Model of Lysosomal Transmembrane Enzyme Deficiency, MPS IIIC. Cells 2024; 13:877. [PMID: 38786099 PMCID: PMC11120110 DOI: 10.3390/cells13100877] [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: 04/02/2024] [Revised: 05/13/2024] [Accepted: 05/15/2024] [Indexed: 05/25/2024] Open
Abstract
Mucopolysaccharidosis III type C (MPS IIIC) is an untreatable neuropathic lysosomal storage disease caused by a genetic deficiency of the lysosomal N-acetyltransferase, HGSNAT, catalyzing a transmembrane acetylation of heparan sulfate. HGSNAT is a transmembrane enzyme incapable of free diffusion between the cells or their cross-correction, which limits development of therapies based on enzyme replacement and gene correction. Since our previous work identified neuroinflammation as a hallmark of the CNS pathology in MPS IIIC, we tested whether it can be corrected by replacement of activated brain microglia with neuroprotective macrophages/microglia derived from a heterologous HSPC transplant. Eight-week-old MPS IIIC (HgsnatP304L) mice were transplanted with HSPC from congenic wild type mice after myeloablation with Busulfan and studied using behavior test battery, starting from the age of 6 months. At the age of ~8 months, mice were sacrificed to study pathological changes in the brain, heparan sulfate storage, and other biomarkers of the disease. We found that the treatment corrected several behavior deficits including hyperactivity and reduction in socialization, but not memory decline. It also improved several features of CNS pathology such as microastroglyosis, expression of pro-inflammatory cytokine IL-1β, and accumulation of misfolded amyloid aggregates in cortical neurons. At the periphery, the treatment delayed development of terminal urinary retention, potentially increasing longevity, and reduced blood levels of heparan sulfate. However, we did not observe correction of lysosomal storage phenotype in neurons and heparan sulfate brain levels. Together, our results demonstrate that neuroinflammation in a neurological lysosomal storage disease, caused by defects in a transmembrane enzyme, can be effectively ameliorated by replacement of microglia bearing the genetic defect with cells from a normal healthy donor. They also suggest that heterologous HSPC transplant, if used together with other methods, such as chaperone therapy or substrate reduction therapy, may constitute an effective combination therapy for MPS IIIC and other disorders with a similar etiology.
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Affiliation(s)
- Xuefang Pan
- Department of Pediatrics and Centre Hospitalier Universitaire Sainte-Justine Research Centre, University of Montreal, Montreal, QC H3T 1C5, Canada; (X.P.); (A.C.); (S.F.)
| | - Antoine Caillon
- Department of Pediatrics and Centre Hospitalier Universitaire Sainte-Justine Research Centre, University of Montreal, Montreal, QC H3T 1C5, Canada; (X.P.); (A.C.); (S.F.)
| | - Shuxian Fan
- Department of Pediatrics and Centre Hospitalier Universitaire Sainte-Justine Research Centre, University of Montreal, Montreal, QC H3T 1C5, Canada; (X.P.); (A.C.); (S.F.)
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 0C7, Canada
| | - Shaukat Khan
- Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA; (S.K.); (S.T.)
| | - Shunji Tomatsu
- Nemours/Alfred I. duPont Hospital for Children, Wilmington, DE 19803, USA; (S.K.); (S.T.)
| | - Alexey V. Pshezhetsky
- Department of Pediatrics and Centre Hospitalier Universitaire Sainte-Justine Research Centre, University of Montreal, Montreal, QC H3T 1C5, Canada; (X.P.); (A.C.); (S.F.)
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC H3A 0C7, Canada
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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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Hewson L, Choo A, Webber DL, Trim PJ, Snel MF, Fedele AO, Hopwood JJ, Hemsley KM, O'Keefe LV. Drosophila melanogaster models of MPS IIIC (Hgsnat-deficiency) highlight the role of glia in disease presentation. J Inherit Metab Dis 2024; 47:340-354. [PMID: 38238109 DOI: 10.1002/jimd.12712] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/18/2023] [Accepted: 12/21/2023] [Indexed: 03/16/2024]
Abstract
Sanfilippo syndrome (Mucopolysaccharidosis type III or MPS III) is a recessively inherited neurodegenerative lysosomal storage disorder. Mutations in genes encoding enzymes in the heparan sulphate degradation pathway lead to the accumulation of partially degraded heparan sulphate, resulting ultimately in the development of neurological deficits. Mutations in the gene encoding the membrane protein heparan-α-glucosaminide N-acetyltransferase (HGSNAT; EC2.3.1.78) cause MPS IIIC (OMIM#252930), typified by impaired cognition, sleep-wake cycle changes, hyperactivity and early death, often before adulthood. The precise disease mechanism that causes symptom emergence remains unknown, posing a significant challenge in the development of effective therapeutics. As HGSNAT is conserved in Drosophila melanogaster, we now describe the creation and characterisation of the first Drosophila models of MPS IIIC. Flies with either an endogenous insertion mutation or RNAi-mediated knockdown of hgsnat were confirmed to have a reduced level of HGSNAT transcripts and age-dependent accumulation of heparan sulphate leading to engorgement of the endo/lysosomal compartment. This resulted in abnormalities at the pre-synapse, defective climbing and reduced overall activity. Altered circadian rhythms (shift in peak morning activity) were seen in hgsnat neuronal knockdown lines. Further, when hgsnat was knocked down in specific glial subsets (wrapping, cortical, astrocytes or subperineural glia), impaired climbing or reduced activity was noted, implying that hgsnat function in these specific glial subtypes contributes significantly to this behaviour and targeting treatments to these cell groups may be necessary to ameliorate or prevent symptom onset. These novel models of MPS IIIC provide critical research tools for delineating the key cellular pathways causal in the onset of neurodegeneration in this presently untreatable disorder.
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Affiliation(s)
- Laura Hewson
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Amanda Choo
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Dani L Webber
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
| | - Paul J Trim
- Proteomics, Metabolomics & MS-Imaging Core, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Marten F Snel
- Proteomics, Metabolomics & MS-Imaging Core, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Anthony O Fedele
- Hopwood Centre for Neurobiology, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - John J Hopwood
- Hopwood Centre for Neurobiology, South Australian Health and Medical Research Institute, Adelaide, South Australia, Australia
| | - Kim M Hemsley
- Childhood Dementia Research Group, Flinders Health and Medical Research Institute, Flinders University, Bedford Park, South Australia, Australia
| | - Louise V O'Keefe
- Department of Molecular and Biomedical Science, School of Biological Sciences, The University of Adelaide, Adelaide, South Australia, Australia
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Taherzadeh M, Zhang E, Londono I, De Leener B, Wang S, Cooper JD, Kennedy TE, Morales CR, Chen Z, Lodygensky GA, Pshezhetsky AV. Severe central nervous system demyelination in Sanfilippo disease. Front Mol Neurosci 2023; 16:1323449. [PMID: 38163061 PMCID: PMC10756675 DOI: 10.3389/fnmol.2023.1323449] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Accepted: 11/23/2023] [Indexed: 01/03/2024] Open
Abstract
Introduction Chronic progressive neuroinflammation is a hallmark of neurological lysosomal storage diseases, including mucopolysaccharidosis III (MPS III or Sanfilippo disease). Since neuroinflammation is linked to white matter tract pathology, we analyzed axonal myelination and white matter density in the mouse model of MPS IIIC HgsnatP304L and post-mortem brain samples of MPS III patients. Methods Brain and spinal cord tissues of human MPS III patients, 6-month-old HgsnatP304L mice and age- and sex-matching wild type mice were analyzed by immunofluorescence to assess levels of myelin-associated proteins, primary and secondary storage materials, and levels of microgliosis. Corpus callosum (CC) region was studied by transmission electron microscopy to analyze axon myelination and morphology of oligodendrocytes and microglia. Mouse brains were analyzed ex vivo by high-filed MRI using Diffusion Basis Spectrum Imaging in Python-Diffusion tensor imaging algorithms. Results Analyses of CC and spinal cord tissues by immunohistochemistry revealed substantially reduced levels of myelin-associated proteins including Myelin Basic Protein, Myelin Associated Glycoprotein, and Myelin Oligodendrocyte Glycoprotein. Furthermore, ultrastructural analyses revealed disruption of myelin sheath organization and reduced myelin thickness in the brains of MPS IIIC mice and human MPS IIIC patients compared to healthy controls. Oligodendrocytes (OLs) in the CC of MPS IIIC mice were scarce, while examination of the remaining cells revealed numerous enlarged lysosomes containing heparan sulfate, GM3 ganglioside or "zebra bodies" consistent with accumulation of lipids and myelin fragments. In addition, OLs contained swollen mitochondria with largely dissolved cristae, resembling those previously identified in the dysfunctional neurons of MPS IIIC mice. Ex vivo Diffusion Basis Spectrum Imaging revealed compelling signs of demyelination (26% increase in radial diffusivity) and tissue loss (76% increase in hindered diffusivity) in CC of MPS IIIC mice. Discussion Our findings demonstrate an important role for white matter injury in the pathophysiology of MPS III. This study also defines specific parameters and brain regions for MRI analysis and suggests that it may become a crucial non-invasive method to evaluate disease progression and therapeutic response.
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Affiliation(s)
- Mahsa Taherzadeh
- Department of Pediatrics, Centre Hospitalier Universitaire (CHU) Sainte-Justine Research Centre, University of Montreal, Montreal, QC, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
| | - Erjun Zhang
- Department of Pediatrics, Centre Hospitalier Universitaire (CHU) Sainte-Justine Research Centre, University of Montreal, Montreal, QC, Canada
| | - Irene Londono
- Department of Pediatrics, Centre Hospitalier Universitaire (CHU) Sainte-Justine Research Centre, University of Montreal, Montreal, QC, Canada
| | - Benjamin De Leener
- Department of Pediatrics, Centre Hospitalier Universitaire (CHU) Sainte-Justine Research Centre, University of Montreal, Montreal, QC, Canada
- NeuroPoly Lab, Institute of Biomedical Engineering, Department of Computer Engineering and Software Engineering, École Polytechnique de Montréal, Montreal, QC, Canada
| | - Sophie Wang
- Pediatric Storage Disorders Laboratory (PSDL), Departments of Pediatrics, Genetics and Neurology, Washington University School of Medicine, St. Louis, MO, United States
| | - Jonathan D. Cooper
- Pediatric Storage Disorders Laboratory (PSDL), Departments of Pediatrics, Genetics and Neurology, Washington University School of Medicine, St. Louis, MO, United States
| | - Timothy E. Kennedy
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
- Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Carlos R. Morales
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
| | - Zesheng Chen
- Department of Pediatrics, Centre Hospitalier Universitaire (CHU) Sainte-Justine Research Centre, University of Montreal, Montreal, QC, Canada
| | - Gregory A. Lodygensky
- Department of Pediatrics, Centre Hospitalier Universitaire (CHU) Sainte-Justine Research Centre, University of Montreal, Montreal, QC, Canada
| | - Alexey V. Pshezhetsky
- Department of Pediatrics, Centre Hospitalier Universitaire (CHU) Sainte-Justine Research Centre, University of Montreal, Montreal, QC, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, QC, Canada
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Kho I, Demina EP, Pan X, Londono I, Cairo CW, Sturiale L, Palmigiano A, Messina A, Garozzo D, Ung RV, Mac-Way F, Bonneil É, Thibault P, Lemaire M, Morales CR, Pshezhetsky AV. Severe kidney dysfunction in sialidosis mice reveals an essential role for neuraminidase 1 in reabsorption. JCI Insight 2023; 8:e166470. [PMID: 37698928 PMCID: PMC10619504 DOI: 10.1172/jci.insight.166470] [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: 10/24/2022] [Accepted: 09/06/2023] [Indexed: 09/14/2023] Open
Abstract
Sialidosis is an ultra-rare multisystemic lysosomal disease caused by mutations in the neuraminidase 1 (NEU1) gene. The severe type II form of the disease manifests with a prenatal/infantile or juvenile onset, bone abnormalities, severe neuropathology, and visceromegaly. A subset of these patients present with nephrosialidosis, characterized by abrupt onset of fulminant glomerular nephropathy. We studied the pathophysiological mechanism of the disease in 2 NEU1-deficient mouse models, a constitutive Neu1-knockout, Neu1ΔEx3, and a conditional phagocyte-specific knockout, Neu1Cx3cr1ΔEx3. Mice of both strains exhibited terminal urinary retention and severe kidney damage with elevated urinary albumin levels, loss of nephrons, renal fibrosis, presence of storage vacuoles, and dysmorphic mitochondria in the intraglomerular and tubular cells. Glycoprotein sialylation in glomeruli, proximal distal tubules, and distal tubules was drastically increased, including that of an endocytic reabsorption receptor megalin. The pool of megalin bearing O-linked glycans with terminal galactose residues, essential for protein targeting and activity, was reduced to below detection levels. Megalin levels were severely reduced, and the protein was directed to lysosomes instead of the apical membrane. Together, our results demonstrated that desialylation by NEU1 plays a crucial role in processing and cellular trafficking of megalin and that NEU1 deficiency in sialidosis impairs megalin-mediated protein reabsorption.
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Affiliation(s)
- Ikhui Kho
- CHU Sainte-Justine Research Center, University of Montreal, Montreal, Québec, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, Québec, Canada
| | - Ekaterina P. Demina
- CHU Sainte-Justine Research Center, University of Montreal, Montreal, Québec, Canada
| | - Xuefang Pan
- CHU Sainte-Justine Research Center, University of Montreal, Montreal, Québec, Canada
| | - Irene Londono
- CHU Sainte-Justine Research Center, University of Montreal, Montreal, Québec, Canada
| | | | - Luisa Sturiale
- CNR, Institute for Polymers, Composites and Biomaterials, Catania, Italy
| | - Angelo Palmigiano
- CNR, Institute for Polymers, Composites and Biomaterials, Catania, Italy
| | - Angela Messina
- CNR, Institute for Polymers, Composites and Biomaterials, Catania, Italy
| | - Domenico Garozzo
- CNR, Institute for Polymers, Composites and Biomaterials, Catania, Italy
| | - Roth-Visal Ung
- CHU de Québec Research Center, L’Hôtel-Dieu de Québec Hospital, Faculty and Department of Medicine, University Laval, Québec City, Québec, Canada
| | - Fabrice Mac-Way
- CHU de Québec Research Center, L’Hôtel-Dieu de Québec Hospital, Faculty and Department of Medicine, University Laval, Québec City, Québec, Canada
| | - Éric Bonneil
- Institute for Research in Immunology and Cancer, University of Montreal, Montreal, Québec, Canada
| | - Pierre Thibault
- Institute for Research in Immunology and Cancer, University of Montreal, Montreal, Québec, Canada
| | - Mathieu Lemaire
- Division of Nephrology, The Hospital for Sick Kids, Faculty of Medicine, University of Toronto, Ontario, Canada
- Cell Biology Program, SickKids Research Institute, Toronto, Ontario, Canada
| | - Carlos R. Morales
- Department of Anatomy and Cell Biology, McGill University, Montreal, Québec, Canada
| | - Alexey V. Pshezhetsky
- CHU Sainte-Justine Research Center, University of Montreal, Montreal, Québec, Canada
- Department of Anatomy and Cell Biology, McGill University, Montreal, Québec, Canada
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Ludwig J, Sawant OB, Wood J, Singamsetty S, Pan X, Bonilha VL, Rao S, Pshezhetsky AV. Histological characterization of retinal degeneration in mucopolysaccharidosis type IIIC. Exp Eye Res 2023; 229:109433. [PMID: 36858249 PMCID: PMC10103010 DOI: 10.1016/j.exer.2023.109433] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 02/14/2023] [Accepted: 02/25/2023] [Indexed: 03/03/2023]
Abstract
Heparan-α-glucosaminide N-acetyltransferase (HGSNAT) participates in lysosomal degradation of heparan sulfate. Mutations in the gene encoding this enzyme cause mucopolysaccharidosis IIIC (MPS IIIC) or Sanfilippo syndrome type C. MPS IIIC patients exhibit progressive neurodegeneration, leading to dementia and death in early adulthood. Currently there is no approved treatment for MPS IIIC. Incidences of non-syndromic retinitis pigmentosa and early signs of night blindness are reported in some MPS IIIC patients, however the majority of ocular phenotypes are not well characterized. The goal of this study was to investigate retinal degeneration phenotype in the Hgsnat knockout mouse model of MPS IIIC and a cadaveric human MPS IIIC eye. Cone and rod photoreceptors in the eyes of homozygous 6-month-old Hgsnat knockout mice and their wild-type counterparts were analyzed using cone arrestin, S-opsin, M-opsin and rhodopsin antibodies. Histological observation was performed on the eye from a 35-year-old MPS IIIC donor. We observed a nearly 50% reduction in the rod photoreceptors density in the Hgsnat knockout mice compared to the littermate wild-type controls. Cone photoreceptor density was unaltered at this age. Severe retinal degeneration was also observed in the MPS IIIC donor eye. To our knowledge, this is the first report characterizing ocular phenotypes arising from deleterious variants in the Hgsnat gene associated with MPS IIIC clinical phenotype. Our findings indicate retinal manifestations may be present even before behavioral manifestations. Thus, we speculate that ophthalmological evaluations could be used as diagnostic indicators of early disease, progression, and end-point evaluation for future MPS IIIC therapies.
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Affiliation(s)
- Jessica Ludwig
- Center for Vision and Eye Banking Research, Eversight, Cleveland, OH, 44103, USA
| | - Onkar B Sawant
- Center for Vision and Eye Banking Research, Eversight, Cleveland, OH, 44103, USA.
| | | | | | - Xuefang Pan
- Sainte-Justine University Hospital Research Center, University of Montreal, Montreal, Quebec, Canada
| | - Vera L Bonilha
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Sujata Rao
- Department of Ophthalmic Research, Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Alexey V Pshezhetsky
- Sainte-Justine University Hospital Research Center, University of Montreal, Montreal, Quebec, Canada; Department of Anatomy and Cell Biology, McGill University, Montreal, Quebec, Canada
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Grasso D, Galderisi S, Santucci A, Bernini A. Pharmacological Chaperones and Protein Conformational Diseases: Approaches of Computational Structural Biology. Int J Mol Sci 2023; 24:ijms24065819. [PMID: 36982893 PMCID: PMC10054308 DOI: 10.3390/ijms24065819] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 03/09/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
Whenever a protein fails to fold into its native structure, a profound detrimental effect is likely to occur, and a disease is often developed. Protein conformational disorders arise when proteins adopt abnormal conformations due to a pathological gene variant that turns into gain/loss of function or improper localization/degradation. Pharmacological chaperones are small molecules restoring the correct folding of a protein suitable for treating conformational diseases. Small molecules like these bind poorly folded proteins similarly to physiological chaperones, bridging non-covalent interactions (hydrogen bonds, electrostatic interactions, and van der Waals contacts) loosened or lost due to mutations. Pharmacological chaperone development involves, among other things, structural biology investigation of the target protein and its misfolding and refolding. Such research can take advantage of computational methods at many stages. Here, we present an up-to-date review of the computational structural biology tools and approaches regarding protein stability evaluation, binding pocket discovery and druggability, drug repurposing, and virtual ligand screening. The tools are presented as organized in an ideal workflow oriented at pharmacological chaperones' rational design, also with the treatment of rare diseases in mind.
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Affiliation(s)
- Daniela Grasso
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, 53100 Siena, Italy
| | - Silvia Galderisi
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, 53100 Siena, Italy
| | - Annalisa Santucci
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, 53100 Siena, Italy
| | - Andrea Bernini
- Department of Biotechnology, Chemistry, and Pharmacy, University of Siena, 53100 Siena, Italy
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