1
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Wiseman JP, Scarrott JM, Alves-Cruzeiro J, Saffari A, Böger C, Karyka E, Dawes E, Davies AK, Marchi PM, Graves E, Fernandes F, Yang ZL, Coldicott I, Hirst J, Webster CP, Highley JR, Hackett N, Angyal A, Silva TD, Higginbottom A, Shaw PJ, Ferraiuolo L, Ebrahimi-Fakhari D, Azzouz M. Pre-clinical development of AP4B1 gene replacement therapy for hereditary spastic paraplegia type 47. EMBO Mol Med 2024:10.1038/s44321-024-00148-5. [PMID: 39358605 DOI: 10.1038/s44321-024-00148-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 09/17/2024] [Accepted: 09/19/2024] [Indexed: 10/04/2024] Open
Abstract
Spastic paraplegia 47 (SPG47) is a neurological disorder caused by mutations in the adaptor protein complex 4 β1 subunit (AP4B1) gene leading to AP-4 complex deficiency. SPG47 is characterised by progressive spastic paraplegia, global developmental delay, intellectual disability and epilepsy. Gene therapy aimed at restoring functional AP4B1 protein levels is a rational therapeutic strategy to ameliorate the disease phenotype. Here we report that a single delivery of adeno-associated virus serotype 9 expressing hAP4B1 (AAV9/hAP4B1) into the cisterna magna leads to widespread gene transfer and restoration of various hallmarks of disease, including AP-4 cargo (ATG9A) mislocalisation, calbindin-positive spheroids in the deep cerebellar nuclei, anatomical brain defects and motor dysfunction, in an SPG47 mouse model. Furthermore, AAV9/hAP4B1-based gene therapy demonstrated a restoration of plasma neurofilament light (NfL) levels of treated mice. Encouraged by these preclinical proof-of-concept data, we conducted IND-enabling studies, including immunogenicity and GLP non-human primate (NHP) toxicology studies. Importantly, NHP safety and biodistribution study revealed no significant adverse events associated with the therapeutic intervention. These findings provide evidence of both therapeutic efficacy and safety, establishing a robust basis for the pursuit of an IND application for clinical trials targeting SPG47 patients.
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Affiliation(s)
- Jessica P Wiseman
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Joseph M Scarrott
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
- Gene Therapy Innovation & Manufacturing Centre (GTIMC), Division of Neuroscience, University of Sheffield, Sheffield, UK
| | - João Alves-Cruzeiro
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
| | - Afshin Saffari
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
- Movement Disorders Program, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
- Division of Child Neurology and Inherited Metabolic Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Cedric Böger
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
- Movement Disorders Program, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Evangelia Karyka
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
- Gene Therapy Innovation & Manufacturing Centre (GTIMC), Division of Neuroscience, University of Sheffield, Sheffield, UK
| | - Emily Dawes
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
| | - Alexandra K Davies
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
- Cambridge Institute for Medical Research, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Paolo M Marchi
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
| | - Emily Graves
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
| | - Fiona Fernandes
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
| | - Zih-Liang Yang
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Ian Coldicott
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Jennifer Hirst
- Cambridge Institute for Medical Research, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK
| | - Christopher P Webster
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - J Robin Highley
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | | | - Adrienn Angyal
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Thushan de Silva
- Department of Infection, Immunity and Cardiovascular Disease, University of Sheffield, Sheffield, UK
| | - Adrian Higginbottom
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
| | - Pamela J Shaw
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK
- Sheffield NIHR Biomedical Research Centre, Sheffield Teaching Hospitals NHS Foundation Trust, Glossop Road, Sheffield, UK
| | - Laura Ferraiuolo
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK
| | - Darius Ebrahimi-Fakhari
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
- Movement Disorders Program, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Mimoun Azzouz
- Sheffield Institute for Translational Neuroscience (SITraN), Division of Neuroscience, University of Sheffield, Sheffield, UK.
- Neuroscience Institute, University of Sheffield, Western Bank, Sheffield, UK.
- Gene Therapy Innovation & Manufacturing Centre (GTIMC), Division of Neuroscience, University of Sheffield, Sheffield, UK.
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2
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Saffari A, Brechmann B, Böger C, Saber WA, Jumo H, Whye D, Wood D, Wahlster L, Alecu JE, Ziegler M, Scheffold M, Winden K, Hubbs J, Buttermore ED, Barrett L, Borner GHH, Davies AK, Ebrahimi-Fakhari D, Sahin M. High-content screening identifies a small molecule that restores AP-4-dependent protein trafficking in neuronal models of AP-4-associated hereditary spastic paraplegia. Nat Commun 2024; 15:584. [PMID: 38233389 PMCID: PMC10794252 DOI: 10.1038/s41467-023-44264-1] [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: 06/07/2023] [Accepted: 12/06/2023] [Indexed: 01/19/2024] Open
Abstract
Unbiased phenotypic screens in patient-relevant disease models offer the potential to detect therapeutic targets for rare diseases. In this study, we developed a high-throughput screening assay to identify molecules that correct aberrant protein trafficking in adapter protein complex 4 (AP-4) deficiency, a rare but prototypical form of childhood-onset hereditary spastic paraplegia characterized by mislocalization of the autophagy protein ATG9A. Using high-content microscopy and an automated image analysis pipeline, we screened a diversity library of 28,864 small molecules and identified a lead compound, BCH-HSP-C01, that restored ATG9A pathology in multiple disease models, including patient-derived fibroblasts and induced pluripotent stem cell-derived neurons. We used multiparametric orthogonal strategies and integrated transcriptomic and proteomic approaches to delineate potential mechanisms of action of BCH-HSP-C01. Our results define molecular regulators of intracellular ATG9A trafficking and characterize a lead compound for the treatment of AP-4 deficiency, providing important proof-of-concept data for future studies.
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Affiliation(s)
- Afshin Saffari
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Division of Child Neurology and Inherited Metabolic Diseases, Heidelberg University Hospital, Heidelberg, Germany
| | - Barbara Brechmann
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Cedric Böger
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Wardiya Afshar Saber
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Hellen Jumo
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Dosh Whye
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Delaney Wood
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Lara Wahlster
- Department of Hematology & Oncology, Boston Children's Hospital & Dana-Farber Cancer Institute, Harvard Medical School, Boston, MA, 02115, USA
| | - Julian E Alecu
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Marvin Ziegler
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Marlene Scheffold
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Kellen Winden
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Jed Hubbs
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Elizabeth D Buttermore
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Lee Barrett
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Georg H H Borner
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Martinsried, 82152, Germany
| | - Alexandra K Davies
- Department of Proteomics and Signal Transduction, Max-Planck-Institute of Biochemistry, Martinsried, 82152, Germany
- School of Biological Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, M13 9PT, UK
| | - Darius Ebrahimi-Fakhari
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
- Movement Disorders Program, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA.
| | - Mustafa Sahin
- Department of Neurology & F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
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3
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Li Y, Zhang C, Peng G. Ap4s1 truncation leads to axonal defects in a zebrafish model of spastic paraplegia 52. Int J Dev Neurosci 2023; 83:753-764. [PMID: 37767851 DOI: 10.1002/jdn.10303] [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: 04/17/2023] [Revised: 08/11/2023] [Accepted: 09/08/2023] [Indexed: 09/29/2023] Open
Abstract
Biallelic mutations in AP4S1, the σ4 subunit of the adaptor protein complex 4 (AP-4), lead to autosomal recessive spastic paraplegia 52 (SPG52). It is a subtype of AP-4-associated hereditary spastic paraplegia (AP-4-HSP), a complex childhood-onset neurogenetic disease characterized by progressive spastic paraplegia of the lower limbs. This disease has so far lacked effective treatment, in part due to a lack of suitable animal models. Here, we used CRISPR/Cas9 technology to generate a truncation mutation in the ap4s1 gene in zebrafish. The ap4s1 truncation led to motor impairment, delayed neurodevelopment, and distal axonal degeneration. This animal model is useful for further research into AP-4 and AP-4-HSP.
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Affiliation(s)
- Yiduo Li
- State Key Laboratory of Medical Neurobiology, Ministry of Education Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Cuizhen Zhang
- State Key Laboratory of Medical Neurobiology, Ministry of Education Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
| | - Gang Peng
- State Key Laboratory of Medical Neurobiology, Ministry of Education Frontiers Center for Brain Science, and Institutes of Brain Science, Fudan University, Shanghai, China
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4
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Wang J, Daniszewski M, Hao MM, Hernández D, Pébay A, Gleeson PA, Fourriere L. Organelle mapping in dendrites of human iPSC-derived neurons reveals dynamic functional dendritic Golgi structures. Cell Rep 2023; 42:112709. [PMID: 37393622 DOI: 10.1016/j.celrep.2023.112709] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2023] [Revised: 05/15/2023] [Accepted: 06/12/2023] [Indexed: 07/04/2023] Open
Abstract
Secretory pathways within dendrites of neurons have been proposed for local transport of newly synthesized proteins. However, little is known about the dynamics of the local secretory system and whether the organelles are transient or stable structures. Here, we quantify the spatial and dynamic behavior of dendritic Golgi and endosomes during differentiation of human neurons generated from induced pluripotent stem cells (iPSCs). In early neuronal development, before and during migration, the entire Golgi apparatus transiently translocates from the soma into dendrites. In mature neurons, dynamic Golgi elements, containing cis and trans cisternae, are transported from the soma along dendrites, in an actin-dependent process. Dendritic Golgi outposts are dynamic and display bidirectional movement. Similar structures were observed in cerebral organoids. Using the retention using selective hooks (RUSH) system, Golgi resident proteins are transported efficiently into Golgi outposts from the endoplasmic reticulum. This study reveals dynamic, functional Golgi structures in dendrites and a spatial map for investigating dendrite trafficking in human neurons.
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Affiliation(s)
- Jingqi Wang
- The Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Maciej Daniszewski
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Marlene M Hao
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Damián Hernández
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Alice Pébay
- Department of Anatomy and Physiology, The University of Melbourne, Parkville, VIC 3010, Australia; Department of Surgery, Royal Melbourne Hospital, The University of Melbourne, Parkville, VIC 3010, Australia
| | - Paul A Gleeson
- The Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia.
| | - Lou Fourriere
- The Department of Biochemistry and Pharmacology and Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Parkville, VIC 3010, Australia.
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5
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Saffari A, Brechmann B, Boeger C, Saber WA, Jumo H, Whye D, Wood D, Wahlster L, Alecu J, Ziegler M, Scheffold M, Winden K, Hubbs J, Buttermore E, Barrett L, Borner G, Davies A, Sahin M, Ebrahimi-Fakhari D. High-Content Small Molecule Screen Identifies a Novel Compound That Restores AP-4-Dependent Protein Trafficking in Neuronal Models of AP-4-Associated Hereditary Spastic Paraplegia. RESEARCH SQUARE 2023:rs.3.rs-3036166. [PMID: 37398196 PMCID: PMC10312991 DOI: 10.21203/rs.3.rs-3036166/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Unbiased phenotypic screens in patient-relevant disease models offer the potential to detect novel therapeutic targets for rare diseases. In this study, we developed a high-throughput screening assay to identify molecules that correct aberrant protein trafficking in adaptor protein complex 4 (AP-4) deficiency, a rare but prototypical form of childhood-onset hereditary spastic paraplegia, characterized by mislocalization of the autophagy protein ATG9A. Using high-content microscopy and an automated image analysis pipeline, we screened a diversity library of 28,864 small molecules and identified a lead compound, C-01, that restored ATG9A pathology in multiple disease models, including patient-derived fibroblasts and induced pluripotent stem cell-derived neurons. We used multiparametric orthogonal strategies and integrated transcriptomic and proteomic approaches to delineate putative molecular targets of C-01 and potential mechanisms of action. Our results define molecular regulators of intracellular ATG9A trafficking and characterize a lead compound for the treatment of AP-4 deficiency, providing important proof-of-concept data for future Investigational New Drug (IND)-enabling studies.
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Affiliation(s)
| | | | | | | | | | - Dosh Whye
- Boston Children's Hospital, Harvard Medical School
| | - Delaney Wood
- Boston Children's Hospital, Harvard Medical School
| | | | - Julian Alecu
- Boston Children's Hospital, Harvard Medical School
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6
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Johns AE, Maragakis NJ. Exploring Motor Neuron Diseases Using iPSC Platforms. Stem Cells 2022; 40:2-13. [PMID: 35511862 PMCID: PMC9199844 DOI: 10.1093/stmcls/sxab006] [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: 06/18/2021] [Accepted: 09/17/2021] [Indexed: 01/21/2023]
Abstract
The degeneration of motor neurons is a pathological hallmark of motor neuron diseases (MNDs), but emerging evidence suggests that neuronal vulnerability extends well beyond this cell subtype. The ability to assess motor function in the clinic is limited to physical examination, electrophysiological measures, and tissue-based or neuroimaging techniques which lack the resolution to accurately assess neuronal dysfunction as the disease progresses. Spinal muscular atrophy (SMA), spinal and bulbar muscular atrophy (SBMA), hereditary spastic paraplegia (HSP), and amyotrophic lateral sclerosis (ALS) are all MNDs with devastating clinical outcomes that contribute significantly to disease burden as patients are no longer able to carry out normal activities of daily living. The critical need to accurately assess the cause and progression of motor neuron dysfunction, especially in the early stages of those diseases, has motivated the use of human iPSC-derived motor neurons (hiPSC-MN) to study the neurobiological mechanisms underlying disease pathogenesis and to generate platforms for therapeutic discovery and testing. As our understanding of MNDs has grown, so too has our need to develop more complex in vitro models which include hiPSC-MN co-cultured with relevant non-neuronal cells in 2D as well as in 3D organoid and spheroid systems. These more complex hiPSC-derived culture systems have led to the implementation of new technologies, including microfluidics, multielectrode array, and machine learning which offer novel insights into the functional correlates of these emerging model systems.
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Affiliation(s)
- Alexandra E Johns
- Department of Neurology, Johns Hopkins University, Baltimore, MD, USA
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7
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Davies AK, Alecu JE, Ziegler M, Vasilopoulou CG, Merciai F, Jumo H, Afshar-Saber W, Sahin M, Ebrahimi-Fakhari D, Borner GHH. AP-4-mediated axonal transport controls endocannabinoid production in neurons. Nat Commun 2022; 13:1058. [PMID: 35217685 PMCID: PMC8881493 DOI: 10.1038/s41467-022-28609-w] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 01/08/2022] [Indexed: 01/20/2023] Open
Abstract
The adaptor protein complex AP-4 mediates anterograde axonal transport and is essential for axon health. AP-4-deficient patients suffer from a severe neurodevelopmental and neurodegenerative disorder. Here we identify DAGLB (diacylglycerol lipase-beta), a key enzyme for generation of the endocannabinoid 2-AG (2-arachidonoylglycerol), as a cargo of AP-4 vesicles. During normal development, DAGLB is targeted to the axon, where 2-AG signalling drives axonal growth. We show that DAGLB accumulates at the trans-Golgi network of AP-4-deficient cells, that axonal DAGLB levels are reduced in neurons from a patient with AP-4 deficiency, and that 2-AG levels are reduced in the brains of AP-4 knockout mice. Importantly, we demonstrate that neurite growth defects of AP-4-deficient neurons are rescued by inhibition of MGLL (monoacylglycerol lipase), the enzyme responsible for 2-AG hydrolysis. Our study supports a new model for AP-4 deficiency syndrome in which axon growth defects arise through spatial dysregulation of endocannabinoid signalling. Davies et al. identify a putative mechanism underlying the childhood neurological disorder AP-4 deficiency syndrome. In the absence of AP-4, an enzyme that makes 2-AG is not transported to the axon, leading to axonal growth defects, which can be rescued by inhibition of 2-AG breakdown.
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Affiliation(s)
- Alexandra K Davies
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, 82152, Germany.
| | - Julian E Alecu
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Marvin Ziegler
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA.,Department of Functional Neuroanatomy, Institute of Anatomy and Cell Biology, Heidelberg University, INF 307, Heidelberg, 69120, Germany
| | - Catherine G Vasilopoulou
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, 82152, Germany
| | - Fabrizio Merciai
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, 82152, Germany.,Department of Pharmacy and PhD Program in Drug Discovery and Development, University of Salerno, 84084, Fisciano, SA, Italy
| | - Hellen Jumo
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Wardiya Afshar-Saber
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Mustafa Sahin
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA.,Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Darius Ebrahimi-Fakhari
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, 02115, USA
| | - Georg H H Borner
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, 82152, Germany.
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8
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Shin J, Nile A, Oh JW. Role of adaptin protein complexes in intracellular trafficking and their impact on diseases. Bioengineered 2021; 12:8259-8278. [PMID: 34565296 PMCID: PMC8806629 DOI: 10.1080/21655979.2021.1982846] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2021] [Revised: 09/15/2021] [Accepted: 09/15/2021] [Indexed: 02/07/2023] Open
Abstract
Adaptin proteins (APs) play a crucial role in intracellular cell trafficking. The 'classical' role of APs is carried out by AP1‒3, which bind to clathrin, cargo, and accessory proteins. Accordingly, AP1-3 are crucial for both vesicle formation and sorting. All APs consist of four subunits that are indispensable for their functions. In fact, based on studies using cells, model organism knockdown/knock-out, and human variants, each subunit plays crucial roles and contributes to the specificity of each AP. These studies also revealed that the sorting and intracellular trafficking function of AP can exert varying effects on pathology by controlling features such as cell development, signal transduction related to the apoptosis and proliferation pathways in cancer cells, organelle integrity, receptor presentation, and viral infection. Although the roles and functions of AP1‒3 are relatively well studied, the functions of the less abundant and more recently identified APs, AP4 and AP5, are still to be investigated. Further studies on these APs may enable a better understanding and targeting of specific diseases.APs known or suggested locations and functions.
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Affiliation(s)
- Juhyun Shin
- Department of Stem Cell and Regenerative Biotechnology and Animal Resources Research Center, Konkuk University, Seoul, Republic of Korea
| | - Arti Nile
- Department of Stem Cell and Regenerative Biotechnology and Animal Resources Research Center, Konkuk University, Seoul, Republic of Korea
| | - Jae-Wook Oh
- Department of Stem Cell and Regenerative Biotechnology and Animal Resources Research Center, Konkuk University, Seoul, Republic of Korea
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9
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Eberhardt K, Jumo H, D'Amore A, Alecu JE, Ziegler M, Afshar Saber W, Sahin M, Ebrahimi-Fakhari D. Generation and characterization of six human induced pluripotent stem cell lines (iPSC) from three families with AP4M1-associated hereditary spastic paraplegia (SPG50). Stem Cell Res 2021; 53:102335. [PMID: 34087981 DOI: 10.1016/j.scr.2021.102335] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2021] [Accepted: 04/02/2021] [Indexed: 11/20/2022] Open
Abstract
Biallelic loss-of-function variants in the subunits of the adaptor protein complex 4 lead to childhood-onset hereditary spastic paraplegia (AP-4-HSP): SPG47 (AP4B1), SPG50 (AP4M1), SPG51 (AP4E1), and SPG52 (AP4S1). Here, we describe the generation of induced pluripotent stem cells (iPSCs) from three AP-4-HSP patients with biallelic, loss-of-function variants in AP4M1 and their sex-matched parents (asymptomatic, heterozygous carriers). Following reprogramming using non-integrating Sendai virus, iPSCs were characterized following standard protocols including karyotyping, embryoid body formation, pluripotency marker expression and STR profiling. These first iPSC lines for SPG50 provide a valuable resource for studying this rare disease and related forms of hereditary spastic paraplegia.
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Affiliation(s)
- Kathrin Eberhardt
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA; Albert-Ludwigs-University Freiburg, Medical School, Freiburg, Germany
| | - Hellen Jumo
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Angelica D'Amore
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Julian E Alecu
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Marvin Ziegler
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Wardiya Afshar Saber
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Mustafa Sahin
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Darius Ebrahimi-Fakhari
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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10
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Rudenskaya GE, Guseva DM, Mironovich OL, Kadnikova VA, Dadali EL, Komar'kov IF, Novoselova OG, Ryzhkova OP. [AP4-assocated hereditary spastic paraplegias]. Zh Nevrol Psikhiatr Im S S Korsakova 2021; 121:71-78. [PMID: 33728854 DOI: 10.17116/jnevro202112102171] [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] [Indexed: 11/18/2022]
Abstract
OBJECTIVE In the course of studies of spastic paraplegias in Russian patients to detect AP4-associated forms, estimate their proportion in the total SPG group and analyze clinical and molecular characteristics. MATERIAL AND METHODS Five families of Russian ethnicity: four with SPG47, one with SPG51 (4 girls and a boy aged 2.5-9 years) were studied. Clinical and genealogical methods, whole-exome sequencing (WES) and verification by familial Sanger sequencing were used. RESULTS In our total group, including 118 families with 21 different forms, SPG AP4-associated forms accounted for 4.2% owing mainly to SPG47 (3.4%, 5th place in SPG structure; 20% and 2nd place in AE subgroup.) In non-consanguineous, unrelated SPG47 families three patients had identical genotypes: homozygosity for an earlier reported mutation c.1160_1161 delCA (p.Thr387ArgfsTer30) in AP4B1 exon 6; the 4th patient was compound-heterozygous for the same mutation and novel c.1240C>T (p.Gln414Ter) in exon 7. Frequency of c.1160_1161 delCA may be caused by founder effect in Slavic populations though the idea needs additional studies. The SPG51 patient was compound heterozygous for novel AP4E1 mutations c.2604delA (p.Ser868fs) and c.3346A>G (p.Arg1116Gly). Parent's heterozygosity in all cases was confirmed by Sanger sequencing. Phenotypes were typical: early development delay, muscle hypotony transforming into sever spasticity, mental deficiency, microceplaly (in all SPG47 cases), epilepsy (in 3 SPG47 and SPG51 cases), MRI changes, mainly hydrocephalus and/or hypoplasia of corpus callosum (in 3 SPG47 cases) and few extraneural signs. CONCLUSION AP4-associated SPG should be taken into consideration in patients with early-onset severe nervous diseases mimicking non-genetic organic CNS disorders and massive exome sequencing (WES or other variants) should be performed.
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Affiliation(s)
| | - D M Guseva
- Research Centre for Medical Genetics, Moscow, Russia
| | | | - V A Kadnikova
- Research Centre for Medical Genetics, Moscow, Russia
| | - E L Dadali
- Research Centre for Medical Genetics, Moscow, Russia
| | | | | | - O P Ryzhkova
- Research Centre for Medical Genetics, Moscow, Russia
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Ziegler M, Russell BE, Eberhardt K, Geisel G, D'Amore A, Sahin M, Kornblum HI, Ebrahimi-Fakhari D. Blended Phenotype of Silver-Russell Syndrome and SPG50 Caused by Maternal Isodisomy of Chromosome 7. NEUROLOGY-GENETICS 2020; 7:e544. [PMID: 33553621 PMCID: PMC7862086 DOI: 10.1212/nxg.0000000000000544] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/26/2020] [Accepted: 10/22/2020] [Indexed: 11/20/2022]
Abstract
Objective Uniparental isodisomy can lead to blended phenotypes of imprinting disorders and autosomal recessive diseases. To determine whether a complex neurodevelopmental disorder was caused by uniparental isodisomy, a detailed clinical and molecular characterization was performed. Methods A combination of clinical, molecular, and imaging data and functional studies in patient-derived fibroblasts. Results We report a 4-year-old female with a blended, complex phenotype of Silver-Russell syndrome (SRS) and hereditary spastic paraplegia type 50 (SPG50) caused by total maternal isodisomy of chromosome 7 (UPiD(7)mat) and a loss-of-function variant in AP4M1 (NM_00472.3: c.59-1G>C, IVS1-1G>C). Functional studies in patient-derived fibroblasts confirmed the loss of adaptor protein complex 4 function. Distinctive facial features, intrauterine growth restriction, short stature, feeding difficulties, and severe gastroesophageal reflux were consistent with SRS. Features associated with SPG50 included early-onset epilepsy, episodes of stereotypical laughter, and thinning of the corpus callosum and ventriculomegaly on brain MRI. Symptoms shared by both syndromes such as developmental delay, short stature, and axial and appendicular hypotonia were also present. Notably, other common manifestations of SPG50 such as microcephaly or spasticity had not developed yet. Conclusions This case highlights that atypical clinical features in patients with well-described imprinting disorders should lead to investigations for recessive conditions caused by variants in genes that localize to the region of homozygosity.
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Affiliation(s)
- Marvin Ziegler
- Department of Neurology and The F.M. Kirby Neurobiology Center (M.Z., K.E., G.G., A.D., M.S., D.E.-F.), Boston Children's Hospital, Harvard Medical School, MA; Department of Functional Neuroanatomy (M.Z.), Institute of Anatomy and Cell Biology, Heidelberg University, Germany; Division of Genetics (B.E.R.), Department of Pediatrics, David Geffen School of Medicine at UCLA; Translational Neuroscience Center (G.G., M.S.), Boston Children's Hospital, Harvard Medical School, MA; and Intellectual and Developmental Disabilities Research Center (H.I.K.), Semel Institute for Neuroscience and Human Behavior and Department of Psychiatry and Biobehavioral Sciences (H.I.K.), David Geffen School of Medicine at UCLA
| | - Bianca E Russell
- Department of Neurology and The F.M. Kirby Neurobiology Center (M.Z., K.E., G.G., A.D., M.S., D.E.-F.), Boston Children's Hospital, Harvard Medical School, MA; Department of Functional Neuroanatomy (M.Z.), Institute of Anatomy and Cell Biology, Heidelberg University, Germany; Division of Genetics (B.E.R.), Department of Pediatrics, David Geffen School of Medicine at UCLA; Translational Neuroscience Center (G.G., M.S.), Boston Children's Hospital, Harvard Medical School, MA; and Intellectual and Developmental Disabilities Research Center (H.I.K.), Semel Institute for Neuroscience and Human Behavior and Department of Psychiatry and Biobehavioral Sciences (H.I.K.), David Geffen School of Medicine at UCLA
| | - Kathrin Eberhardt
- Department of Neurology and The F.M. Kirby Neurobiology Center (M.Z., K.E., G.G., A.D., M.S., D.E.-F.), Boston Children's Hospital, Harvard Medical School, MA; Department of Functional Neuroanatomy (M.Z.), Institute of Anatomy and Cell Biology, Heidelberg University, Germany; Division of Genetics (B.E.R.), Department of Pediatrics, David Geffen School of Medicine at UCLA; Translational Neuroscience Center (G.G., M.S.), Boston Children's Hospital, Harvard Medical School, MA; and Intellectual and Developmental Disabilities Research Center (H.I.K.), Semel Institute for Neuroscience and Human Behavior and Department of Psychiatry and Biobehavioral Sciences (H.I.K.), David Geffen School of Medicine at UCLA
| | - Gregory Geisel
- Department of Neurology and The F.M. Kirby Neurobiology Center (M.Z., K.E., G.G., A.D., M.S., D.E.-F.), Boston Children's Hospital, Harvard Medical School, MA; Department of Functional Neuroanatomy (M.Z.), Institute of Anatomy and Cell Biology, Heidelberg University, Germany; Division of Genetics (B.E.R.), Department of Pediatrics, David Geffen School of Medicine at UCLA; Translational Neuroscience Center (G.G., M.S.), Boston Children's Hospital, Harvard Medical School, MA; and Intellectual and Developmental Disabilities Research Center (H.I.K.), Semel Institute for Neuroscience and Human Behavior and Department of Psychiatry and Biobehavioral Sciences (H.I.K.), David Geffen School of Medicine at UCLA
| | - Angelica D'Amore
- Department of Neurology and The F.M. Kirby Neurobiology Center (M.Z., K.E., G.G., A.D., M.S., D.E.-F.), Boston Children's Hospital, Harvard Medical School, MA; Department of Functional Neuroanatomy (M.Z.), Institute of Anatomy and Cell Biology, Heidelberg University, Germany; Division of Genetics (B.E.R.), Department of Pediatrics, David Geffen School of Medicine at UCLA; Translational Neuroscience Center (G.G., M.S.), Boston Children's Hospital, Harvard Medical School, MA; and Intellectual and Developmental Disabilities Research Center (H.I.K.), Semel Institute for Neuroscience and Human Behavior and Department of Psychiatry and Biobehavioral Sciences (H.I.K.), David Geffen School of Medicine at UCLA
| | - Mustafa Sahin
- Department of Neurology and The F.M. Kirby Neurobiology Center (M.Z., K.E., G.G., A.D., M.S., D.E.-F.), Boston Children's Hospital, Harvard Medical School, MA; Department of Functional Neuroanatomy (M.Z.), Institute of Anatomy and Cell Biology, Heidelberg University, Germany; Division of Genetics (B.E.R.), Department of Pediatrics, David Geffen School of Medicine at UCLA; Translational Neuroscience Center (G.G., M.S.), Boston Children's Hospital, Harvard Medical School, MA; and Intellectual and Developmental Disabilities Research Center (H.I.K.), Semel Institute for Neuroscience and Human Behavior and Department of Psychiatry and Biobehavioral Sciences (H.I.K.), David Geffen School of Medicine at UCLA
| | - Harley I Kornblum
- Department of Neurology and The F.M. Kirby Neurobiology Center (M.Z., K.E., G.G., A.D., M.S., D.E.-F.), Boston Children's Hospital, Harvard Medical School, MA; Department of Functional Neuroanatomy (M.Z.), Institute of Anatomy and Cell Biology, Heidelberg University, Germany; Division of Genetics (B.E.R.), Department of Pediatrics, David Geffen School of Medicine at UCLA; Translational Neuroscience Center (G.G., M.S.), Boston Children's Hospital, Harvard Medical School, MA; and Intellectual and Developmental Disabilities Research Center (H.I.K.), Semel Institute for Neuroscience and Human Behavior and Department of Psychiatry and Biobehavioral Sciences (H.I.K.), David Geffen School of Medicine at UCLA
| | - Darius Ebrahimi-Fakhari
- Department of Neurology and The F.M. Kirby Neurobiology Center (M.Z., K.E., G.G., A.D., M.S., D.E.-F.), Boston Children's Hospital, Harvard Medical School, MA; Department of Functional Neuroanatomy (M.Z.), Institute of Anatomy and Cell Biology, Heidelberg University, Germany; Division of Genetics (B.E.R.), Department of Pediatrics, David Geffen School of Medicine at UCLA; Translational Neuroscience Center (G.G., M.S.), Boston Children's Hospital, Harvard Medical School, MA; and Intellectual and Developmental Disabilities Research Center (H.I.K.), Semel Institute for Neuroscience and Human Behavior and Department of Psychiatry and Biobehavioral Sciences (H.I.K.), David Geffen School of Medicine at UCLA
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12
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D'Amore A, Tessa A, Naef V, Bassi MT, Citterio A, Romaniello R, Fichi G, Galatolo D, Mero S, Battini R, Bertocci G, Baldacci J, Sicca F, Gemignani F, Ricca I, Rubegni A, Hirst J, Marchese M, Sahin M, Ebrahimi-Fakhari D, Santorelli FM. Loss of ap4s1 in zebrafish leads to neurodevelopmental defects resembling spastic paraplegia 52. Ann Clin Transl Neurol 2020; 7:584-589. [PMID: 32216065 PMCID: PMC7187712 DOI: 10.1002/acn3.51018] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 02/26/2020] [Accepted: 02/27/2020] [Indexed: 11/30/2022] Open
Abstract
Autosomal recessive spastic paraplegia 52 is caused by biallelic mutations in AP4S1 which encodes a subunit of the adaptor protein complex 4 (AP‐4). Using next‐generation sequencing, we identified three novel unrelated SPG52 patients from a cohort of patients with cerebral palsy. The discovered variants in AP4S1 lead to reduced AP‐4 complex formation in patient‐derived fibroblasts. To further understand the role of AP4S1 in neuronal development and homeostasis, we engineered the first zebrafish model of AP‐4 deficiency using morpholino‐mediated knockdown of ap4s1. In this model, we discovered several phenotypes mimicking SPG52, including altered CNS development, locomotor deficits, and abnormal neuronal excitability.
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Affiliation(s)
- Angelica D'Amore
- Department of Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy.,Department of Biology, University of Pisa, Pisa, Italy.,Department of Neurology & The F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Alessandra Tessa
- Department of Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Valentina Naef
- Department of Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Maria Teresa Bassi
- Laboratory of Molecular Biology, Scientific Institute IRCCS E. Medea, Bosisio Parini, Lecco, Italy
| | - Andrea Citterio
- Laboratory of Molecular Biology, Scientific Institute IRCCS E. Medea, Bosisio Parini, Lecco, Italy
| | - Romina Romaniello
- Neuropsychiatry and Neurorehabilitation Unit, Scientific Institute, IRCCS Eugenio Medea, Bosisio Parini, Lecco, Italy
| | - Gianluca Fichi
- Department of Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Daniele Galatolo
- Department of Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Serena Mero
- Department of Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Roberta Battini
- Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Giulia Bertocci
- Department of Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Jacopo Baldacci
- Department of Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Federico Sicca
- Department of Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy.,Department of Developmental Neuroscience, IRCCS Stella Maris Foundation, Pisa, Italy
| | | | - Ivana Ricca
- Department of Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Anna Rubegni
- Department of Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Jennifer Hirst
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge, United Kingdom
| | - Maria Marchese
- Department of Molecular Medicine, IRCCS Stella Maris Foundation, Pisa, Italy
| | - Mustafa Sahin
- Department of Neurology & The F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA
| | - Darius Ebrahimi-Fakhari
- Department of Neurology & The F.M. Kirby Neurobiology Center, Boston Children's Hospital, Harvard Medical School, Boston, MA
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13
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Behne R, Teinert J, Wimmer M, D’Amore A, Davies AK, Scarrott JM, Eberhardt K, Brechmann B, Chen IPF, Buttermore ED, Barrett L, Dwyer S, Chen T, Hirst J, Wiesener A, Segal D, Martinuzzi A, Duarte ST, Bennett JT, Bourinaris T, Houlden H, Roubertie A, Santorelli FM, Robinson M, Azzouz M, Lipton JO, Borner GHH, Sahin M, Ebrahimi-Fakhari D. Adaptor protein complex 4 deficiency: a paradigm of childhood-onset hereditary spastic paraplegia caused by defective protein trafficking. Hum Mol Genet 2020; 29:320-334. [PMID: 31915823 PMCID: PMC7001721 DOI: 10.1093/hmg/ddz310] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/22/2019] [Accepted: 12/05/2019] [Indexed: 12/25/2022] Open
Abstract
Deficiency of the adaptor protein complex 4 (AP-4) leads to childhood-onset hereditary spastic paraplegia (AP-4-HSP): SPG47 (AP4B1), SPG50 (AP4M1), SPG51 (AP4E1) and SPG52 (AP4S1). This study aims to evaluate the impact of loss-of-function variants in AP-4 subunits on intracellular protein trafficking using patient-derived cells. We investigated 15 patient-derived fibroblast lines and generated six lines of induced pluripotent stem cell (iPSC)-derived neurons covering a wide range of AP-4 variants. All patient-derived fibroblasts showed reduced levels of the AP4E1 subunit, a surrogate for levels of the AP-4 complex. The autophagy protein ATG9A accumulated in the trans-Golgi network and was depleted from peripheral compartments. Western blot analysis demonstrated a 3-5-fold increase in ATG9A expression in patient lines. ATG9A was redistributed upon re-expression of AP4B1 arguing that mistrafficking of ATG9A is AP-4-dependent. Examining the downstream effects of ATG9A mislocalization, we found that autophagic flux was intact in patient-derived fibroblasts both under nutrient-rich conditions and when autophagy is stimulated. Mitochondrial metabolism and intracellular iron content remained unchanged. In iPSC-derived cortical neurons from patients with AP4B1-associated SPG47, AP-4 subunit levels were reduced while ATG9A accumulated in the trans-Golgi network. Levels of the autophagy marker LC3-II were reduced, suggesting a neuron-specific alteration in autophagosome turnover. Neurite outgrowth and branching were reduced in AP-4-HSP neurons pointing to a role of AP-4-mediated protein trafficking in neuronal development. Collectively, our results establish ATG9A mislocalization as a key marker of AP-4 deficiency in patient-derived cells, including the first human neuron model of AP-4-HSP, which will aid diagnostic and therapeutic studies.
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Affiliation(s)
- Robert Behne
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- Department of Neurology, University Hospital Würzburg, 97080 Würzburg, Germany
| | - Julian Teinert
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- Division of Pediatric Neurology and Metabolic Medicine, Center for Child and Adolescent Medicine, University Hospital Heidelberg, 69120 Heidelberg, Germany
| | - Miriam Wimmer
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Angelica D’Amore
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- Molecular Medicine, IRCCS Fondazione Stella Maris, 56018 Pisa, Italy
| | - Alexandra K Davies
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Joseph M Scarrott
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, UK
| | - Kathrin Eberhardt
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Barbara Brechmann
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Ivy Pin-Fang Chen
- Translational Neuroscience Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Elizabeth D Buttermore
- Translational Neuroscience Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Lee Barrett
- Translational Neuroscience Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Sean Dwyer
- Translational Neuroscience Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Teresa Chen
- Translational Neuroscience Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Jennifer Hirst
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Antje Wiesener
- Institute of Human Genetics, Friedrich-Alexander Universität Erlangen-Nürnberg, 91054 Erlangen, Germany
| | - Devorah Segal
- Division of Pediatric Neurology, Department of Pediatrics, Weill Cornell Medicine, New York City, NY 10021, USA
| | - Andrea Martinuzzi
- Scientific Institute, IRCCS E. Medea, Unità Operativa Conegliano, 31015 Treviso, Italy
| | - Sofia T Duarte
- Department of Pediatric Neurology, Centro Hospitalar de Lisboa Central, 1169-050 Lisbon, Portugal
| | - James T Bennett
- Division of Genetic Medicine, Department of Pediatrics, University of Washington, Seattle, WA 98195, USA
| | - Thomas Bourinaris
- Department of Molecular Neuroscience, UCL Institute of Neurology, London WC1E 6BT, UK
| | - Henry Houlden
- Department of Molecular Neuroscience, UCL Institute of Neurology, London WC1E 6BT, UK
| | | | | | - Margaret Robinson
- Cambridge Institute for Medical Research, University of Cambridge, Cambridge CB2 0XY, UK
| | - Mimoun Azzouz
- Department of Neuroscience, Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield S10 2HQ, UK
| | - Jonathan O Lipton
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- Division of Sleep Medicine, Harvard Medical School, Boston, MA 02115, USA
| | - Georg H H Borner
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, 82152 Martinsried, Germany
| | - Mustafa Sahin
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
- Translational Neuroscience Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Darius Ebrahimi-Fakhari
- Department of Neurology, The F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Harvard Medical School, Boston, MA 02115, USA
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