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Paz E, Jain S, Gottfried I, Staretz-Chacham O, Mahajnah M, Bagchi P, Seyfried NT, Ashery U, Azem A. Biochemical and neurophysiological effects of deficiency of the mitochondrial import protein TIMM50. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.20.594480. [PMID: 38826427 PMCID: PMC11142075 DOI: 10.1101/2024.05.20.594480] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2024]
Abstract
TIMM50, an essential TIM23 complex subunit, is suggested to facilitate the import of ∼60% of the mitochondrial proteome. In this study, we characterized a TIMM50 disease causing mutation in human fibroblasts, and noted significant decreases in TIM23 core protein levels (TIMM50, TIMM17A/B, and TIMM23). Strikingly, TIMM50 deficiency had no impact on the steady state levels of most of its substrates, challenging the currently accepted import dogma of the essential general import role of TIM23 and suggesting that fully functioning TIM23 complex is not essential for maintaining the steady state level of the majority of mitochondrial proteins. As TIMM50 mutations have been linked to severe neurological phenotypes, we aimed to characterize TIMM50 defects in manipulated mammalian neurons. TIMM50 knockdown in mouse neurons had a minor effect on the steady state level of most of the mitochondrial proteome, supporting the results observed in patient fibroblasts. Amongst the few affected TIM23 substrates, a decrease in the steady state level of components of the intricate oxidative phosphorylation and mitochondrial ribosome complexes was evident. This led to declined respiration rates in fibroblasts and neurons, reduced cellular ATP levels and defective mitochondrial trafficking in neuronal processes, possibly contributing to the developmental defects observed in patients with TIMM50 disease. Finally, increased electrical activity was observed in TIMM50 deficient mice neuronal cells, which correlated with reduced levels of KCNJ10 and KCNA2 plasma membrane potassium channels, likely underlying the patients' epileptic phenotype.
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Bhattacharjee R, Jolly LA, Corbett MA, Wee IC, Rao SR, Gardner AE, Ritchie T, van Hugte EJH, Ciptasari U, Piltz S, Noll JE, Nazri N, van Eyk CL, White M, Fornarino D, Poulton C, Baynam G, Collins-Praino LE, Snel MF, Nadif Kasri N, Hemsley KM, Thomas PQ, Kumar R, Gecz J. Compromised transcription-mRNA export factor THOC2 causes R-loop accumulation, DNA damage and adverse neurodevelopment. Nat Commun 2024; 15:1210. [PMID: 38331934 PMCID: PMC10853216 DOI: 10.1038/s41467-024-45121-5] [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: 06/16/2023] [Accepted: 01/15/2024] [Indexed: 02/10/2024] Open
Abstract
We implicated the X-chromosome THOC2 gene, which encodes the largest subunit of the highly-conserved TREX (Transcription-Export) complex, in a clinically complex neurodevelopmental disorder with intellectual disability as the core phenotype. To study the molecular pathology of this essential eukaryotic gene, we generated a mouse model based on a hypomorphic Thoc2 exon 37-38 deletion variant of a patient with ID, speech delay, hypotonia, and microcephaly. The Thoc2 exon 37-38 deletion male (Thoc2Δ/Y) mice recapitulate the core phenotypes of THOC2 syndrome including smaller size and weight, and significant deficits in spatial learning, working memory and sensorimotor functions. The Thoc2Δ/Y mouse brain development is significantly impacted by compromised THOC2/TREX function resulting in R-loop accumulation, DNA damage and consequent cell death. Overall, we suggest that perturbed R-loop homeostasis, in stem cells and/or differentiated cells in mice and the patient, and DNA damage-associated functional alterations are at the root of THOC2 syndrome.
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Affiliation(s)
- Rudrarup Bhattacharjee
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Lachlan A Jolly
- Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia
- School of Biomedicine, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Mark A Corbett
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Ing Chee Wee
- Discipline of Anatomy and Pathology, School of Biomedicine, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Sushma R Rao
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Proteomics, Metabolomics and MS-imaging Core Facility, South Australian Health and Medical Research Institute, and Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Alison E Gardner
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Tarin Ritchie
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Eline J H van Hugte
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, 6500, HB, the Netherlands
| | - Ummi Ciptasari
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, 6500, HB, the Netherlands
| | - Sandra Piltz
- Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia
- School of Biomedicine, The University of Adelaide, Adelaide, SA, 5005, Australia
- South Australian Health and Medical Research Institute, Adelaide, SA, 5000, Australia
| | - Jacqueline E Noll
- School of Biomedicine, Faculty of Health and Medical Sciences, University of Adelaide and Precision Cancer Medicine Theme, Solid Tumour Program, South Australian Health and Medical Research Institute, Adelaide, SA, 5000, Australia
| | - Nazzmer Nazri
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Childhood Dementia Research Group, College of Medicine and Public Health, Flinders Health & Medical Research Institute, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - Clare L van Eyk
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Melissa White
- Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia
- School of Biomedicine, The University of Adelaide, Adelaide, SA, 5005, Australia
- South Australian Health and Medical Research Institute, Adelaide, SA, 5000, Australia
| | - Dani Fornarino
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Cathryn Poulton
- Undiagnosed Diseases Program, Genetic Services of WA, King Edward Memorial Hospital, Subiaco, WA, 6008, Australia
| | - Gareth Baynam
- Undiagnosed Diseases Program, Genetic Services of WA, King Edward Memorial Hospital, Subiaco, WA, 6008, Australia
- Western Australian Register of Developmental Anomalies, King Edward Memorial Hospital, Subiaco, WA, 6008, Australia
- Rare Care Centre, Perth Children's Hospital, Nedlands, WA, 6009, Australia
| | - Lyndsey E Collins-Praino
- Discipline of Anatomy and Pathology, School of Biomedicine, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Marten F Snel
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Proteomics, Metabolomics and MS-imaging Core Facility, South Australian Health and Medical Research Institute, and Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Nael Nadif Kasri
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behavior, Nijmegen, 6500, HB, the Netherlands
| | - Kim M Hemsley
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Childhood Dementia Research Group, College of Medicine and Public Health, Flinders Health & Medical Research Institute, Flinders University, Bedford Park, Adelaide, SA, 5042, Australia
| | - Paul Q Thomas
- Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia
- School of Biomedicine, The University of Adelaide, Adelaide, SA, 5005, Australia
- South Australian Health and Medical Research Institute, Adelaide, SA, 5000, Australia
| | - Raman Kumar
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia
- Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia
| | - Jozef Gecz
- Adelaide Medical School, The University of Adelaide, Adelaide, SA, 5005, Australia.
- Robinson Research Institute, The University of Adelaide, Adelaide, SA, 5005, Australia.
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3
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Sela M, Poley M, Mora-Raimundo P, Kagan S, Avital A, Kaduri M, Chen G, Adir O, Rozencweig A, Weiss Y, Sade O, Leichtmann-Bardoogo Y, Simchi L, Aga-Mizrachi S, Bell B, Yeretz-Peretz Y, Zaid Or A, Choudhary A, Rosh I, Cordeiro D, Cohen-Adiv S, Berdichevsky Y, Odeh A, Shklover J, Shainsky-Roitman J, Schroeder JE, Hershkovitz D, Hasson P, Ashkenazi A, Stern S, Laviv T, Ben-Zvi A, Avital A, Ashery U, Maoz BM, Schroeder A. Brain-Targeted Liposomes Loaded with Monoclonal Antibodies Reduce Alpha-Synuclein Aggregation and Improve Behavioral Symptoms in Parkinson's Disease. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2023; 35:e2304654. [PMID: 37753928 PMCID: PMC7615408 DOI: 10.1002/adma.202304654] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Revised: 09/04/2023] [Indexed: 09/28/2023]
Abstract
Monoclonal antibodies (mAbs) hold promise in treating Parkinson's disease (PD), although poor delivery to the brain hinders their therapeutic application. In the current study, it is demonstrated that brain-targeted liposomes (BTL) enhance the delivery of mAbs across the blood-brain-barrier (BBB) and into neurons, thereby allowing the intracellular and extracellular treatment of the PD brain. BTL are decorated with transferrin to improve brain targeting through overexpressed transferrin-receptors on the BBB during PD. BTL are loaded with SynO4, a mAb that inhibits alpha-synuclein (AS) aggregation, a pathological hallmark of PD. It is shown that 100-nm BTL cross human BBB models intact and are taken up by primary neurons. Within neurons, SynO4 is released from the nanoparticles and bound to its target, thereby reducing AS aggregation, and enhancing neuronal viability. In vivo, intravenous BTL administration results in a sevenfold increase in mAbs in brain cells, decreasing AS aggregation and neuroinflammation. Treatment with BTL also improve behavioral motor function and learning ability in mice, with a favorable safety profile. Accordingly, targeted nanotechnologies offer a valuable platform for drug delivery to treat brain neurodegeneration.
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Affiliation(s)
- Mor Sela
- The Louis Family Laboratory for Targeted Drug Delivery and Personalized Medicine Technologies, Department of Chemical Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Maria Poley
- The Louis Family Laboratory for Targeted Drug Delivery and Personalized Medicine Technologies, Department of Chemical Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Patricia Mora-Raimundo
- The Louis Family Laboratory for Targeted Drug Delivery and Personalized Medicine Technologies, Department of Chemical Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Shaked Kagan
- The Louis Family Laboratory for Targeted Drug Delivery and Personalized Medicine Technologies, Department of Chemical Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Aviram Avital
- The Norman Seiden Multidisciplinary Program for Nanoscience and Nanotechnology, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Maya Kaduri
- The Louis Family Laboratory for Targeted Drug Delivery and Personalized Medicine Technologies, Department of Chemical Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Gal Chen
- The Louis Family Laboratory for Targeted Drug Delivery and Personalized Medicine Technologies, Department of Chemical Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
- The Interdisciplinary Program for Biotechnology, Technion - Israel Institute of Technology, Haifa 32000, Israel
| | - Omer Adir
- The Norman Seiden Multidisciplinary Program for Nanoscience and Nanotechnology, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Adi Rozencweig
- The Louis Family Laboratory for Targeted Drug Delivery and Personalized Medicine Technologies, Department of Chemical Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Yfat Weiss
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ofir Sade
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | | | - Lilach Simchi
- Department of Occupational Therapy, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa 3498838, Israel
| | - Shlomit Aga-Mizrachi
- Department of Occupational Therapy, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa 3498838, Israel
| | - Batia Bell
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9190500, Israel
| | - Yoel Yeretz-Peretz
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9190500, Israel
| | - Aviv Zaid Or
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ashwani Choudhary
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel
| | - Idan Rosh
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel
| | - Diogo Cordeiro
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel
| | - Stav Cohen-Adiv
- The Department of Cell and Developmental Biology, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Yevgeny Berdichevsky
- The Department of Cell and Developmental Biology, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Anas Odeh
- Department of Genetics and Developmental Biology, The Rappaport Faculty of Medicine and Research Institute, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Jeny Shklover
- The Louis Family Laboratory for Targeted Drug Delivery and Personalized Medicine Technologies, Department of Chemical Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Janna Shainsky-Roitman
- The Louis Family Laboratory for Targeted Drug Delivery and Personalized Medicine Technologies, Department of Chemical Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Joshua E. Schroeder
- Spine Unit, Orthopedic Complex, Hadassah Hebrew University Medical Center, Kiryat Hadassah, POB 12000, Jerusalem 9190500, Israel
| | - Dov Hershkovitz
- Department of Pathology, Tel Aviv Sourasky Medical Center, Tel Aviv 6997801, Israel
- Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Peleg Hasson
- Department of Genetics and Developmental Biology, The Rappaport Faculty of Medicine and Research Institute, Technion – Israel Institute of Technology, Haifa 32000, Israel
| | - Avraham Ashkenazi
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- The Department of Cell and Developmental Biology, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Shani Stern
- Sagol Department of Neurobiology, Faculty of Natural Sciences, University of Haifa, Haifa 3498838, Israel
| | - Tal Laviv
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Physiology and Pharmacology, Faculty of Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ayal Ben-Zvi
- Department of Developmental Biology and Cancer Research, The Institute for Medical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem 9190500, Israel
| | - Avi Avital
- Department of Occupational Therapy, Faculty of Social Welfare and Health Sciences, University of Haifa, Haifa 3498838, Israel
| | - Uri Ashery
- School of Neurobiology, Biochemistry and Biophysics, George S. Wise Faculty of Life Sciences, Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Ben M. Maoz
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv 6997801, Israel
- Department of Biomedical Engineering, Tel Aviv University, Tel Aviv 6997801, Israel
- The Center for Nanoscience and Nanotechnology, Tel Aviv University, Tel Aviv 6997801, Israel
- Sagol Center for Regenerative Medicine, Tel Aviv University, Tel Aviv 6997801, Israel
| | - Avi Schroeder
- The Louis Family Laboratory for Targeted Drug Delivery and Personalized Medicine Technologies, Department of Chemical Engineering, Technion – Israel Institute of Technology, Haifa 32000, Israel
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Kulkarni AS, Burns MR, Brundin P, Wesson DW. Linking α-synuclein-induced synaptopathy and neural network dysfunction in early Parkinson’s disease. Brain Commun 2022; 4:fcac165. [PMID: 35822101 PMCID: PMC9272065 DOI: 10.1093/braincomms/fcac165] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 03/11/2022] [Accepted: 06/20/2022] [Indexed: 01/18/2023] Open
Abstract
Abstract
The prodromal phase of Parkinson’s disease is characterized by aggregation of the misfolded pathogenic protein α-synuclein in select neural centres, co-occurring with non-motor symptoms including sensory and cognitive loss, and emotional disturbances. It is unclear whether neuronal loss is significant during the prodrome. Underlying these symptoms are synaptic impairments and aberrant neural network activity. However, the relationships between synaptic defects and network-level perturbations are not established. In experimental models, pathological α-synuclein not only impacts neurotransmission at the synaptic level, but also leads to changes in brain network-level oscillatory dynamics—both of which likely contribute to non-motor deficits observed in Parkinson’s disease. Here we draw upon research from both human subjects and experimental models to propose a ‘synapse to network prodrome cascade’ wherein before overt cell death, pathological α-synuclein induces synaptic loss and contributes to aberrant network activity, which then gives rise to prodromal symptomology. As the disease progresses, abnormal patterns of neural activity ultimately lead to neuronal loss and clinical progression of disease. Finally, we outline goals and research needed to unravel the basis of functional impairments in Parkinson’s disease and other α-synucleinopathies.
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Affiliation(s)
- Aishwarya S Kulkarni
- Department of Pharmacology & Therapeutics, University of Florida , 1200 Newell Dr, Gainesville, FL 32610 , USA
| | - Matthew R Burns
- Department of Neurology, University of Florida , 1200 Newell Dr, Gainesville, FL 32610 , USA
- Norman Fixel Institute for Neurological Disorders, University of Florida , 1200 Newell Dr, Gainesville, FL 32610 , USA
| | - Patrik Brundin
- Pharma Research and Early Development (pRED), F. Hoffman-La Roche , Little Falls, NJ , USA
| | - Daniel W Wesson
- Department of Pharmacology & Therapeutics, University of Florida , 1200 Newell Dr, Gainesville, FL 32610 , USA
- Norman Fixel Institute for Neurological Disorders, University of Florida , 1200 Newell Dr, Gainesville, FL 32610 , USA
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5
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Martín-de-Saavedra MD, Dos Santos M, Culotta L, Varea O, Spielman BP, Parnell E, Forrest MP, Gao R, Yoon S, McCoig E, Jalloul HA, Myczek K, Khalatyan N, Hall EA, Turk LS, Sanz-Clemente A, Comoletti D, Lichtenthaler SF, Burgdorf JS, Barbolina MV, Savas JN, Penzes P. Shed CNTNAP2 ectodomain is detectable in CSF and regulates Ca 2+ homeostasis and network synchrony via PMCA2/ATP2B2. Neuron 2022; 110:627-643.e9. [PMID: 34921780 PMCID: PMC8857041 DOI: 10.1016/j.neuron.2021.11.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2021] [Revised: 10/11/2021] [Accepted: 11/19/2021] [Indexed: 11/29/2022]
Abstract
Although many neuronal membrane proteins undergo proteolytic cleavage, little is known about the biological significance of neuronal ectodomain shedding (ES). Here, we show that the neuronal sheddome is detectable in human cerebrospinal fluid (hCSF) and is enriched in neurodevelopmental disorder (NDD) risk factors. Among shed synaptic proteins is the ectodomain of CNTNAP2 (CNTNAP2-ecto), a prominent NDD risk factor. CNTNAP2 undergoes activity-dependent ES via MMP9 (matrix metalloprotease 9), and CNTNAP2-ecto levels are reduced in the hCSF of individuals with autism spectrum disorder. Using mass spectrometry, we identified the plasma membrane Ca2+ ATPase (PMCA) extrusion pumps as novel CNTNAP2-ecto binding partners. CNTNAP2-ecto enhances the activity of PMCA2 and regulates neuronal network dynamics in a PMCA2-dependent manner. Our data underscore the promise of sheddome analysis in discovering neurobiological mechanisms, provide insight into the biology of ES and its relationship with the CSF, and reveal a mechanism of regulation of Ca2+ homeostasis and neuronal network synchrony by a shed ectodomain.
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Affiliation(s)
| | - Marc Dos Santos
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Lorenza Culotta
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Olga Varea
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Benjamin P Spielman
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Euan Parnell
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Marc P Forrest
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Ruoqi Gao
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Sehyoun Yoon
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Emmarose McCoig
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Hiba A Jalloul
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Kristoffer Myczek
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Natalia Khalatyan
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Elizabeth A Hall
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Liam S Turk
- Child Health Institute of New Jersey, New Brunswick, NJ 08901, USA; Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, New Brunswick, NJ 08901, USA
| | - Antonio Sanz-Clemente
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Davide Comoletti
- Child Health Institute of New Jersey, New Brunswick, NJ 08901, USA; Department of Neuroscience and Cell Biology, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, New Brunswick, NJ 08901, USA; Department of Pediatrics, Robert Wood Johnson Medical School, Rutgers, the State University of New Jersey, New Brunswick, NJ 08901, USA; School of Biological Sciences, Victoria University of Wellington, Wellington 6140, New Zealand
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE), 81377 Munich, Germany; Department of Neuroproteomics, School of Medicine, Klinikum rechts der Isar, and Institute for Advanced Study, Technical University of Munich, 81675 Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), 81377 Munich, Germany
| | - Jeffrey S Burgdorf
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Center for Autism and Neurodevelopment, Northwestern University, Chicago, IL 60611, USA; Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Maria V Barbolina
- Department of Biopharmaceutical Sciences, University of Illinois at Chicago, Chicago, IL 60607, USA
| | - Jeffrey N Savas
- Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA
| | - Peter Penzes
- Department of Physiology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Center for Autism and Neurodevelopment, Northwestern University, Chicago, IL 60611, USA; Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
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6
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Disrupted Excitatory Synaptic Contacts and Altered Neuronal Network Activity Underpins the Neurological Phenotype in PCDH19-Clustering Epilepsy (PCDH19-CE). Mol Neurobiol 2021; 58:2005-2018. [PMID: 33411240 DOI: 10.1007/s12035-020-02242-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 12/02/2020] [Indexed: 12/21/2022]
Abstract
PCDH19-Clustering Epilepsy (PCDH19-CE) is an infantile onset disorder caused by mutation of the X-linked PCDH19 gene. Intriguingly, heterozygous females are affected while hemizygous males are not. While there is compelling evidence that this disorder stems from the coexistence of WT and PCDH19-null cells, the cellular mechanism underpinning the neurological phenotype remains unclear. Here, we investigate the impact of Pcdh19 WT and KO neuron mosaicism on synaptogenesis and network activity. Using our previously established knock-in and knock-out mouse models, together with CRISPR-Cas9 genome editing technology, we demonstrate a reduction in excitatory synaptic contacts between PCDH19-expressing and PCDH19-null neurons. Significantly altered neuronal morphology and neuronal network activities were also identified in the mixed populations. In addition, we show that in Pcdh19 heterozygous mice, where the coexistence of WT and KO neurons naturally occurs, aberrant contralateral axonal branching is present. Overall, our data show that mosaic expression of PCDH19 disrupts physiological neurite communication leading to abnormal neuronal activity, a hallmark of PCDH19-CE.
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7
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Michaeli L, Gottfried I, Bykhovskaia M, Ashery U. Phosphatidylinositol (4, 5)-bisphosphate targets double C2 domain protein B to the plasma membrane. Traffic 2017; 18:825-839. [PMID: 28941037 DOI: 10.1111/tra.12528] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 09/18/2017] [Accepted: 09/18/2017] [Indexed: 01/05/2023]
Abstract
Double C2 domain protein B (DOC2B) is a high-affinity Ca2+ sensor that translocates from the cytosol to the plasma membrane (PM) and promotes vesicle priming and fusion. However, the molecular mechanism underlying its translocation and targeting to the PM in living cells is not completely understood. DOC2B interacts in vitro with the PM components phosphatidylserine, phosphatidylinositol (4, 5)-bisphosphate [PI(4, 5)P2 ] and target SNAREs (t-SNAREs). Here, we show that PI(4, 5)P2 hydrolysis at the PM of living cells abolishes DOC2B translocation, whereas manipulations of t-SNAREs and other phosphoinositides have no effect. Moreover, we were able to redirect DOC2B to intracellular membranes by synthesizing PI(4, 5)P2 in those membranes. Molecular dynamics simulations and mutagenesis in the calcium and PI(4, 5)P2 -binding sites strengthened our findings, demonstrating that both calcium and PI(4, 5)P2 are required for the DOC2B-PM association and revealing multiple PI(4, 5)P2 -C2B interactions. In addition, we show that DOC2B translocation to the PM is ATP-independent and occurs in a diffusion-like manner. Our data suggest that the Ca2+ -triggered translocation of DOC2B is diffusion-driven and aimed at PI(4, 5)P2 -containing membranes.
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Affiliation(s)
- Lirin Michaeli
- Department of Neurobiology, Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel
| | - Irit Gottfried
- Department of Neurobiology, Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel
| | | | - Uri Ashery
- Department of Neurobiology, Faculty of Life Sciences, Tel-Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, Tel-Aviv University, Tel Aviv, Israel
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Iram T, Trudler D, Kain D, Kanner S, Galron R, Vassar R, Barzilai A, Blinder P, Fishelson Z, Frenkel D. Astrocytes from old Alzheimer's disease mice are impaired in Aβ uptake and in neuroprotection. Neurobiol Dis 2016; 96:84-94. [DOI: 10.1016/j.nbd.2016.08.001] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 07/11/2016] [Accepted: 08/16/2016] [Indexed: 10/21/2022] Open
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Shaping Neuronal Network Activity by Presynaptic Mechanisms. PLoS Comput Biol 2015; 11:e1004438. [PMID: 26372048 PMCID: PMC4570815 DOI: 10.1371/journal.pcbi.1004438] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Accepted: 06/23/2015] [Indexed: 02/06/2023] Open
Abstract
Neuronal microcircuits generate oscillatory activity, which has been linked to basic functions such as sleep, learning and sensorimotor gating. Although synaptic release processes are well known for their ability to shape the interaction between neurons in microcircuits, most computational models do not simulate the synaptic transmission process directly and hence cannot explain how changes in synaptic parameters alter neuronal network activity. In this paper, we present a novel neuronal network model that incorporates presynaptic release mechanisms, such as vesicle pool dynamics and calcium-dependent release probability, to model the spontaneous activity of neuronal networks. The model, which is based on modified leaky integrate-and-fire neurons, generates spontaneous network activity patterns, which are similar to experimental data and robust under changes in the model's primary gain parameters such as excitatory postsynaptic potential and connectivity ratio. Furthermore, it reliably recreates experimental findings and provides mechanistic explanations for data obtained from microelectrode array recordings, such as network burst termination and the effects of pharmacological and genetic manipulations. The model demonstrates how elevated asynchronous release, but not spontaneous release, synchronizes neuronal network activity and reveals that asynchronous release enhances utilization of the recycling vesicle pool to induce the network effect. The model further predicts a positive correlation between vesicle priming at the single-neuron level and burst frequency at the network level; this prediction is supported by experimental findings. Thus, the model is utilized to reveal how synaptic release processes at the neuronal level govern activity patterns and synchronization at the network level. The activity of neuronal networks underlies basic neural functions such as sleep, learning and sensorimotor gating. Computational models of neuronal networks have been developed to capture the complexity of the network activity and predict how neuronal networks generate spontaneous activity. However, most computational models do not simulate the intricate synaptic release process that governs the interaction between neurons and has been shown to significantly impact neuronal network activity and animal behavior, learning and memory. Our paper demonstrates the importance of simulating the elaborate synaptic release process to understand how neuronal networks generate spontaneous activity and respond to manipulations of the release process. The model provides mechanistic explanations and predictions for experimental pharmacological and genetic manipulations. Thus, the model presents a novel computational platform to understand how mechanistic changes in the synaptic release process modulate network oscillatory activity that might impact basic neural functions.
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Friedrich R, Gottfried I, Ashery U. Munc13-1 Translocates to the Plasma Membrane in a Doc2B- and Calcium-Dependent Manner. Front Endocrinol (Lausanne) 2013; 4:119. [PMID: 24062723 PMCID: PMC3775473 DOI: 10.3389/fendo.2013.00119] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 08/27/2013] [Indexed: 11/13/2022] Open
Abstract
Munc13-1 is a presynaptic protein activated by calcium, calmodulin, and diacylglycerols (DAG) that is known to enhance vesicle priming. Doc2B is another presynaptic protein that translocates to the plasma membrane (PM) upon elevation of internal calcium concentration ([Ca(2+)]i) to the submicromolar range, and increases both spontaneous and asynchronous release in a calcium-dependent manner. We speculated that Doc2B also recruits Munc13-1 to the PM since these two proteins have been shown to interact physiologically and this interaction is enhanced by Ca(2+). However, this calcium-dependent co-translocation has never actually been shown. To examine this possibility, we expressed both proteins tagged to fluorescent proteins in PC12 cells and stimulated the cells to investigate the recruitment hypothesis using imaging techniques. We found that Munc13-1 does indeed translocate to the PM upon elevation in [Ca(2+)]i, but only when co-expressed with Doc2B. Interestingly, Munc13-1 co-translocates at a slower rate than Doc2B. Moreover, while Doc2B dislocates from the PM as soon as the [Ca(2+)]i returns to basal levels, Munc13-1 dislocates at a slower rate and a fraction of it accumulates on the PM. This accumulation is more pronounced under subsequent stimulations, suggesting that Munc13-1 accumulation builds up as some other factors accumulate at the PM. Munc13-1 co-translocation and accumulation was reduced when its mutant Munc13-1(H567K), which is unable to bind DAG, was co-expressed with Doc2B, suggesting that Munc13-1 accumulation depends on DAG levels. These results suggest that Doc2B enables recruitment of Munc13-1 to the PM in a [Ca(2+)]i-dependent manner and offers another possible Munc13-1-regulatory mechanism that is both calcium- and Doc2B-dependent.
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Affiliation(s)
- Reut Friedrich
- Department of Neurobiology, Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Irit Gottfried
- Department of Neurobiology, Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Uri Ashery
- Department of Neurobiology, Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
- *Correspondence: Uri Ashery, Department of Neurobiology, The George S. Wise Faculty of Life Sciences, Tel Aviv University, Ramat Aviv, Tel Aviv 69978, Israel e-mail:
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