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Nyame K, Xiong J, de Jong AP, Alsohybe HN, Raaben M, Hartmann G, Simcox JA, Blomen VA, Abu-Remaileh M. PLA2G15 is a Lysosomal BMP Hydrolase with Ester Position Specificity and its Targeting Ameliorates Lysosomal Disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.07.597919. [PMID: 38895439 PMCID: PMC11185675 DOI: 10.1101/2024.06.07.597919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/21/2024]
Abstract
Lysosomes catabolize lipids and other biological molecules, a function essential for cellular and organismal homeostasis. Key to lipid catabolism in the lysosome is bis(monoacylglycero)phosphate (BMP), a major lipid constituent of intralysosomal vesicles (ILVs) and a stimulator of lipid-degrading enzymes. BMP levels are altered in a broad spectrum of human conditions, including neurodegenerative diseases. Although BMP synthase was recently discovered, it has long been thought that BMP's unique stereochemistry confers resistance to acid phospholipases, a requirement for its role in the lysosome. Here, we demonstrate that PLA2G15, a major lysosomal phospholipase, efficiently hydrolyzes BMP with primary esters regardless of stereochemistry. Interestingly, we discover that BMP's unique esterification position is what confers resistance to hydrolysis. Purified PLA2G15 catabolizes most BMP species derived from cell and tissue lysosomes under acidic conditions. Furthermore, PLA2G15 catalytic activity against synthesized BMP stereoisomers with primary esters was comparable to its canonical substrates. Conversely, BMP with secondary esters is intrinsically stable in vitro and requires acyl migration for hydrolysis in lysosomes. Consistent with our biochemical data, PLA2G15-deficient tissues and cells accumulate multiple BMP species, a phenotype reversible by supplementing wildtype PLA2G15 but not its catalytically dead mutant. Increasing BMP levels by targeting PLA2G15 reverses the cholesterol accumulation phenotype in Niemann Pick Disease Type C (NPC1) patient fibroblasts and significantly ameliorate disease pathologies in NPC1-deficient mice leading to extended lifespan. Our findings establish the rules that govern the stability of BMP in the lysosome and identify PLA2G15 as a lysosomal BMP hydrolase and as a potential target for modulating BMP levels for therapeutic intervention.
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Eratne D, Lewis C, Kelso W, Loi S, Chiu WHM, Blennow K, Zetterberg H, Santillo AF, Velakoulis D, Walterfang M. Plasma neurofilament light chain is increased in Niemann-Pick Type C but glial fibrillary acidic protein remains normal. Acta Neuropsychiatr 2024:1-6. [PMID: 38533577 DOI: 10.1017/neu.2024.14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/28/2024]
Abstract
OBJECTIVE Niemann-Pick Type C (NPC) is a genetic neurodegenerative lysosomal storage disorder commonly associated with psychiatric symptoms and delays to accurate diagnosis and treatment. This study investigated biomarker levels and diagnostic utility of plasma neurofilament light chain (NfL) and glial fibrillary acidic protein (GFAP) in NPC compared to healthy controls. METHODS Patients with NPC were recruited from a specialist assessment and management service. Data was available from an age and sex-matched healthy control group. NfL and GFAP were measured on Quanterix Simoa HD-X analysers and groups compared using generalised linear models. NfL levels were compared to, and percentiles derived from, recently developed NfL reference ranges. RESULTS Plasma NfL was significantly elevated in 11 patients with NPC compared to 25 controls (mean 17.1 vs. 7.4 pg/ml, p < 0.001), and reference ranges (all >98th percentile). NfL distinguished NPC from controls with high accuracy. GFAP levels were not elevated in NPC (66.6 vs. 75.1 pg/ml). DISCUSSION The study adds important evidence on the potential diagnostic utility of plasma NfL in NPC, extends the literature of NfL as a diagnostic tool to differentiate neurodegenerative from primary psychiatric disorders, and adds support to the pathology in NPC primarily involving neuronal, particularly axonal, degeneration.
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Affiliation(s)
- Dhamidhu Eratne
- Neuropsychiatry Centre, Royal Melbourne Hospital, Melbourne, VIC, Australia
- Melbourne Neuropsychiatry Centre & Department of Psychiatry, University of Melbourne, Melbourne, VIC, Australia
| | - Courtney Lewis
- Neuropsychiatry Centre, Royal Melbourne Hospital, Melbourne, VIC, Australia
- Department of Psychiatry, University of Melbourne, Melbourne, VIC, Australia
| | - Wendy Kelso
- Neuropsychiatry Centre, Royal Melbourne Hospital, Melbourne, VIC, Australia
| | - Samantha Loi
- Neuropsychiatry Centre, Royal Melbourne Hospital, Melbourne, VIC, Australia
- Department of Psychiatry, University of Melbourne, Melbourne, VIC, Australia
| | - Wei-Hsuan Michelle Chiu
- Neuropsychiatry Centre, Royal Melbourne Hospital, Melbourne, VIC, Australia
- Department of Psychiatry, University of Melbourne, Melbourne, VIC, Australia
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, The Dahlgren's Academy, University of Gothenburg, Gothenburg, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
- UK Dementia Research Institute at UCL, London, UK
- Hong Kong Center for Neurodegenerative Diseases, Clear Water Bay, Hong Kong, China
- Wisconsin Alzheimer's Disease Research Center, University of Wisconsin School of Medicine and Public Health, University of Wisconsin-Madison, Madison, WI, USA
| | - Alexander F Santillo
- Department of Clinical Sciences, Clinical Memory Research Unit, Faculty of Medicine, Lund University, Malmö, Sweden
| | - Dennis Velakoulis
- Neuropsychiatry Centre, Royal Melbourne Hospital, Melbourne, VIC, Australia
- Department of Psychiatry, University of Melbourne, Melbourne, VIC, Australia
| | - Mark Walterfang
- Neuropsychiatry Centre, Royal Melbourne Hospital, Melbourne, VIC, Australia
- Department of Psychiatry, University of Melbourne, Melbourne, VIC, Australia
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Lopergolo D, Bianchi S, Gallus GN, Locci S, Pucci B, Leoni V, Gasparini D, Tardelli E, Chincarini A, Sestini S, Santorelli FM, Zetterberg H, De Stefano N, Mignarri A. Familial Alzheimer's disease associated with heterozygous NPC1 mutation. J Med Genet 2024; 61:332-339. [PMID: 37989569 DOI: 10.1136/jmg-2023-109219] [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: 02/14/2023] [Accepted: 10/14/2023] [Indexed: 11/23/2023]
Abstract
INTRODUCTION NPC1 mutations are responsible for Niemann-Pick disease type C (NPC), a rare autosomal recessive neurodegenerative disease. Patients harbouring heterozygous NPC1 mutations may rarely show parkinsonism or dementia. Here, we describe for the first time a large family with an apparently autosomal dominant late-onset Alzheimer's disease (AD) harbouring a novel heterozygous NPC1 mutation. METHODS All the five living siblings belonging to the family were evaluated. We performed clinical evaluation, neuropsychological tests, assessment of cerebrospinal fluid markers of amyloid deposition, tau pathology and neurodegeneration (ATN), structural neuroimaging and brain amyloid-positron emission tomography. Oxysterol serum levels were also tested. A wide next-generation sequencing panel of genes associated with neurodegenerative diseases and a whole exome sequencing analysis were performed. RESULTS We detected the novel heterozygous c.3034G>T (p.Gly1012Cys) mutation in NPC1, shared by all the siblings. No other point mutations or deletions in NPC1 or NPC2 were found. In four siblings, a diagnosis of late-onset AD was defined according to clinical characterisation and ATN biomarkers (A+, T+, N+) and serum oxysterol analysis showed increased 7-ketocholesterol and cholestane-3β,5α,6β-triol. DISCUSSION We describe a novel NPC1 heterozygous mutation harboured by different members of a family with autosomal dominant late-onset amnesic AD without NPC-associated features. A missense mutation in homozygous state in the same aminoacidic position has been previously reported in a patient with NPC with severe phenotype. The alteration of serum oxysterols in our family corroborates the pathogenic role of our NPC1 mutation. Our work, illustrating clinical and biochemical disease hallmarks associated with NPC1 heterozygosity in patients affected by AD, provides relevant insights into the pathogenetic mechanisms underlying this possible novel association.
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Affiliation(s)
- Diego Lopergolo
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- UOC Neurologia e Malattie Neurometaboliche, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - Silvia Bianchi
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- UOC Neurologia e Malattie Neurometaboliche, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - Gian Nicola Gallus
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- UOC Neurologia e Malattie Neurometaboliche, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - Sara Locci
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- UOC Neurologia e Malattie Neurometaboliche, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - Barbara Pucci
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- UOC Neurologia e Neurofisiologia Clinica, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - Valerio Leoni
- Laboratory of Clinical Chemistry, Hospital of Desio, ASST Brianza, School of Medicine and Surgery, University of Milano Bicocca, Milan, Italy
| | - Daniele Gasparini
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- UOC Neurologia e Malattie Neurometaboliche, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - Elisa Tardelli
- Unit of Nuclear Medicine, Department of Diagnostic Imaging, PO - S. Stefano, Azienda U.S.L. Toscana Centro, Prato, italy
| | | | - Stelvio Sestini
- Unit of Nuclear Medicine, Department of Diagnostic Imaging, PO - S. Stefano, Azienda U.S.L. Toscana Centro, Prato, italy
| | - Filippo Maria Santorelli
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Stella Maris Foundation, Calambrone, Italy
| | - Henrik Zetterberg
- Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- UK Dementia Research Institute at UCL, London, UK
- Department of Neurodegenerative Disease, UCL Institute of Neurology, London, UK
- Hong Kong Center for Neurodegenerative Diseases, Hong Kong Special Administrative Region, People's Republic of China
| | - Nicola De Stefano
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- UOC Neurologia e Malattie Neurometaboliche, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
| | - Andrea Mignarri
- Department of Medicine, Surgery and Neurosciences, University of Siena, Siena, Italy
- UOC Neurologia e Malattie Neurometaboliche, Azienda Ospedaliero-Universitaria Senese, Siena, Italy
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Cawley NX, Giddens S, Farhat NM, Luke RA, Scott KEJ, Mohamed HO, Dang Do A, Berry-Kravis E, Cologna SM, Liu F, Porter FD. Elevated cerebrospinal fluid ubiquitin C-terminal hydrolase-L1 levels correlate with phenotypic severity and therapeutic response in Niemann-Pick disease, type C1. Mol Genet Metab 2023; 140:107656. [PMID: 37517328 PMCID: PMC10803635 DOI: 10.1016/j.ymgme.2023.107656] [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: 03/22/2023] [Revised: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 08/01/2023]
Abstract
BACKGROUND Niemann-Pick disease, type C1 (NPC1) is an ultrarare, recessive disorder due to pathological variants of NPC1. The NPC1 phenotype is characterized by progressive cerebellar ataxia and cognitive impairment. Although classically a childhood/adolescent disease, NPC1 is heterogeneous with respect to the age of onset of neurological signs and symptoms. While miglustat has shown to be clinically effective, there are currently no FDA approved drugs to treat NPC1. Identification and characterization of biomarkers may provide tools to facilitate therapeutic trials. Ubiquitin C-terminal hydrolase-L1 (UCHL1) is a protein which is highly expressed by neurons and is a biomarker of neuronal damage. We thus measured cerebrospinal fluid (CSF) levels of UCHL1 in individuals with NPC1. METHODS CSF levels of UCHL1 were measured using a Quanterix Neuroplex 4 assay in 94 individuals with NPC1 and 35 age-appropriate comparison samples. Cross-sectional and longitudinal CSF UCHL1 levels were then evaluated for correlation with phenotypic measures and treatment status. RESULTS CSF UCHL1 levels were markedly elevated (3.3-fold) in individuals with NPC1 relative to comparison samples. The CSF UCHL1 levels showed statistically significant (adj p < 0.0001), moderate, positive correlations with both the 17- and 5-domain NPC Neurological Severity Scores and the Annual Severity Increment Scores. Miglustat treatment significantly decreased (adj p < 0.0001) CSF UCHL1 levels by 30% (95% CI 17-40%). CONCLUSIONS CSF UCHL1 levels are elevated in NPC1, increase with increasing clinical severity and decrease in response to therapy with miglustat. Based on these data, UCHL1 may be a useful biomarker to monitor disease progression and therapeutic response in individuals with NPC1.
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Affiliation(s)
- Niamh X Cawley
- Section on Molecular Dysmorphology, Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Spencer Giddens
- Applied and Computational Mathematics and Statistics, University of Notre Dame, South Bend, IN, USA
| | - Nicole M Farhat
- Section on Molecular Dysmorphology, Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Rachel A Luke
- Section on Molecular Dysmorphology, Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Katelin E J Scott
- Section on Molecular Dysmorphology, Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Hibaaq O Mohamed
- Section on Molecular Dysmorphology, Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - An Dang Do
- Unit on Cellular Stress in Development and Diseases, Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | | | - Stephanie M Cologna
- Department of Chemistry and Laboratory of Integrative Neuroscience, University of Illinois Chicago, Chicago, IL, USA
| | - Fang Liu
- Applied and Computational Mathematics and Statistics, University of Notre Dame, South Bend, IN, USA
| | - Forbes D Porter
- Section on Molecular Dysmorphology, Division of Translational Medicine, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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5
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Campbell K, Cawley NX, Luke R, Scott KEJ, Johnson N, Farhat NY, Alexander D, Wassif CA, Li W, Cologna SM, Berry-Kravis E, Do AD, Dale RK, Porter FD. Identification of cerebral spinal fluid protein biomarkers in Niemann-Pick disease, type C1. Biomark Res 2023; 11:14. [PMID: 36721240 PMCID: PMC9887810 DOI: 10.1186/s40364-023-00448-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Accepted: 01/03/2023] [Indexed: 02/02/2023] Open
Abstract
BACKGROUND Niemann-Pick disease, type C1 (NPC1) is an ultrarare, recessive, lethal, lysosomal disease characterized by progressive cerebellar ataxia and cognitive impairment. Although the NPC1 phenotype is heterogeneous with variable age of onset, classical NPC1 is a pediatric disorder. Currently there are no therapies approved by the FDA and therapeutics trials for NPC1 are complicated by disease rarity, heterogeneity, and the relatively slow rate of neurological decline. Thus, identification of disease relevant biomarkers is necessary to provide tools that can support drug development efforts for this devastating neurological disease. METHODS Proximal extension assays (O-link® Explore 1536) were used to compare cerebrospinal fluid (CSF) samples from individuals with NPC1 enrolled in a natural history study and non-NPC1 comparison samples. Relative expression levels of 1467 proteins were determined, and candidate protein biomarkers were identified by evaluating fold-change and adjusted Kruskal-Wallis test p-values. Selected proteins were orthogonally confirmed using ELISA. To gain insight into disease progression and severity we evaluated the altered protein expression with respect to clinically relevant phenotypic aspects: NPC Neurological Severity Score (NPC1 NSS), Annual Severity Increment Score (ASIS) and age of neurological onset. RESULTS This study identified multiple proteins with altered levels in CSF from individuals with NPC1 compared to non-NPC1 samples. These included proteins previously shown to be elevated in NPC1 (NEFL, MAPT, CHIT1, CALB1) and additional proteins confirmed by orthogonal assays (PARK7, CALB2/calretinin, CHI3L1/YKL-40, MIF, CCL18 and ENO2). Correlations with clinically relevant phenotypic parameters demonstrated moderate negative (p = 0.0210, r = -0.41) and possible moderate positive (p = 0.0631, r = 0.33) correlation of CSF CALB2 levels with age of neurological onset and ASIS, respectively. CSF CHI3L1 levels showed a moderate positive (p = 0.0183, r = 0.40) correlation with the concurrent NPC1 NSS. A strong negative correlation (p = 0.0016, r = -0.648) was observed between CSF CCL18 and age of neurological onset for childhood/adolescent cases. CSF CCL18 levels also showed a strong positive correlation (p = 0.0017, r = 0.61) with ASIS. CONCLUSION Our study identified and validated multiple proteins in CSF from individuals with NPC1 that are candidates for further investigation in a larger cohort. These analytes may prove to be useful as supportive data in therapeutic trials. TRIAL REGISTRATIONS NCT00344331, NCT00001721, NCT02931682.
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Affiliation(s)
- Kiersten Campbell
- grid.420089.70000 0000 9635 8082Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 10CRC, Rm. 1-3330, 10 Center Dr., Bethesda, MD 20879 USA
| | - Niamh X. Cawley
- grid.420089.70000 0000 9635 8082Section On Molecular Dysmorphology, Division of Translational Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
| | - Rachel Luke
- grid.420089.70000 0000 9635 8082Section On Molecular Dysmorphology, Division of Translational Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
| | - Katelin E. J. Scott
- grid.420089.70000 0000 9635 8082Section On Molecular Dysmorphology, Division of Translational Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
| | - Nicholas Johnson
- grid.420089.70000 0000 9635 8082Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 10CRC, Rm. 1-3330, 10 Center Dr., Bethesda, MD 20879 USA
| | - Nicole Y. Farhat
- grid.420089.70000 0000 9635 8082Section On Molecular Dysmorphology, Division of Translational Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
| | - Derek Alexander
- grid.420089.70000 0000 9635 8082Section On Molecular Dysmorphology, Division of Translational Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
| | - Christopher A. Wassif
- grid.420089.70000 0000 9635 8082Section On Molecular Dysmorphology, Division of Translational Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
| | - Wenping Li
- grid.185648.60000 0001 2175 0319Department of Chemistry and Laboratory of Integrative Neuroscience, University of Illinois Chicago, Chicago, IL USA
| | - Stephanie M. Cologna
- grid.185648.60000 0001 2175 0319Department of Chemistry and Laboratory of Integrative Neuroscience, University of Illinois Chicago, Chicago, IL USA
| | | | - An Dang Do
- grid.420089.70000 0000 9635 8082Unit On Cellular Stress in Development and Diseases, Division of Translational Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
| | - Ryan K. Dale
- grid.420089.70000 0000 9635 8082Bioinformatics and Scientific Programming Core, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, 10CRC, Rm. 1-3330, 10 Center Dr., Bethesda, MD 20879 USA
| | - Forbes D. Porter
- grid.420089.70000 0000 9635 8082Section On Molecular Dysmorphology, Division of Translational Research, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD USA
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Welford RW, Farine H, Steiner M, Garzotti M, Dobrenis K, Sievers C, Strasser DS, Amraoui Y, Groenen PM, Giugliani R, Mengel E. Plasma neurofilament light, glial fibrillary acidic protein and lysosphingolipid biomarkers for pharmacodynamics and disease monitoring of GM2 and GM1 gangliosidoses patients. Mol Genet Metab Rep 2022; 30:100843. [PMID: 35242574 PMCID: PMC8856936 DOI: 10.1016/j.ymgmr.2022.100843] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2021] [Revised: 01/24/2022] [Accepted: 01/24/2022] [Indexed: 12/03/2022] Open
Abstract
GM2 and GM1 gangliosidoses are genetic, neurodegenerative lysosomal sphingolipid storage disorders. The earlier the age of onset, the more severe the clinical presentation and progression, with infantile, juvenile and late-onset presentations broadly delineated into separate phenotypic subtypes. Gene and substrate reduction therapies, both of which act directly on sphingolipidosis are entering clinical trials for treatment of these disorders. Simple to use biomarkers for disease monitoring are urgently required to support and expedite these clinical trials. Here, lysosphingolipid and protein biomarkers of sphingolipidosis and neuropathology respectively, were assessed in plasma samples from 33 GM2 gangliosidosis patients, 13 GM1 gangliosidosis patients, and compared to 66 controls. LysoGM2 and lysoGM1 were detectable in 31/33 GM2 gangliosidosis and 12/13 GM1 gangliosidosis patient samples respectively, but not in any controls. Levels of the axonal damage marker Neurofilament light (NF-L) were highly elevated in both GM2 and GM1 gangliosidosis patient plasma samples, with no overlap with controls. Levels of the astrocytosis biomarker Glial fibrillary acidic protein (GFAP) were also elevated in samples from both patient populations, albeit with some overlap with controls. In GM2 gangliosidosis patient plasma NF-L, Tau, GFAP and lysoGM2 were all most highly elevated in infantile onset patients, indicating a relationship to severity and phenotype. Plasma NF-L and liver lysoGM2 were also elevated in a GM2 gangliosidosis mouse model, and were lowered by treatment with a drug that slowed disease progression. These results indicate that lysosphingolipids and NF-L/GFAP have potential to monitor pharmacodynamics and pathogenic processes respectively in GM2 and GM1 gangliosidoses patients.
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