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Maity S, Huang Y, Kilgore MD, Thurmon AN, Vaasjo LO, Galazo MJ, Xu X, Cao J, Wang X, Ning B, Liu N, Fan J. Mapping dynamic molecular changes in hippocampal subregions after traumatic brain injury through spatial proteomics. Clin Proteomics 2024; 21:32. [PMID: 38735925 PMCID: PMC11089002 DOI: 10.1186/s12014-024-09485-6] [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: 01/24/2024] [Accepted: 04/24/2024] [Indexed: 05/14/2024] Open
Abstract
BACKGROUND Traumatic brain injury (TBI) often results in diverse molecular responses, challenging traditional proteomic studies that measure average changes at tissue levels and fail to capture the complexity and heterogeneity of the affected tissues. Spatial proteomics offers a solution by providing insights into sub-region-specific alterations within tissues. This study focuses on the hippocampal sub-regions, analyzing proteomic expression profiles in mice at the acute (1 day) and subacute (7 days) phases of post-TBI to understand subregion-specific vulnerabilities and long-term consequences. METHODS Three mice brains were collected from each group, including Sham, 1-day post-TBI and 7-day post-TBI. Hippocampal subregions were extracted using Laser Microdissection (LMD) and subsequently analyzed by label-free quantitative proteomics. RESULTS The spatial analysis reveals region-specific protein abundance changes, highlighting the elevation of FN1, LGALS3BP, HP, and MUG-1 in the stratum moleculare (SM), suggesting potential immune cell enrichment post-TBI. Notably, established markers of chronic traumatic encephalopathy, IGHM and B2M, exhibit specific upregulation in the dentate gyrus bottom (DG2) independent of direct mechanical injury. Metabolic pathway analysis identifies disturbances in glucose and lipid metabolism, coupled with activated cholesterol synthesis pathways enriched in SM at 7-Day post-TBI and subsequently in deeper DG1 and DG2 suggesting a role in neurogenesis and the onset of recovery. Coordinated activation of neuroglia and microtubule dynamics in DG2 suggest recovery mechanisms in less affected regions. Cluster analysis revealed spatial variations post-TBI, indicative of dysregulated neuronal plasticity and neurogenesis and further predisposition to neurological disorders. TBI-induced protein upregulation (MUG-1, PZP, GFAP, TJP, STAT-1, and CD44) across hippocampal sub-regions indicates shared molecular responses and links to neurological disorders. Spatial variations were demonstrated by proteins dysregulated in both or either of the time-points exclusively in each subregion (ELAVL2, CLIC1 in PL, CD44 and MUG-1 in SM, and SHOC2, LGALS3 in DG). CONCLUSIONS Utilizing advanced spatial proteomics techniques, the study unveils the dynamic molecular responses in distinct hippocampal subregions post-TBI. It uncovers region-specific vulnerabilities and dysregulated neuronal processes, and potential recovery-related pathways that contribute to our understanding of TBI's neurological consequences and provides valuable insights for biomarker discovery and therapeutic targets.
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Affiliation(s)
- Sudipa Maity
- Center for Cellular and Molecular Diagnostics, Tulane University School of Medicine, New Orleans, LA, USA
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Yuanyu Huang
- Center for Cellular and Molecular Diagnostics, Tulane University School of Medicine, New Orleans, LA, USA
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Mitchell D Kilgore
- Clinical Neuroscience Research Center, Department of Neurosurgery and Neurology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Abbigail N Thurmon
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, USA
- Tulane Brain Institute, New Orleans, LA, USA
| | | | - Maria J Galazo
- Department of Cell and Molecular Biology, Tulane University, New Orleans, LA, USA
- Tulane Brain Institute, New Orleans, LA, USA
| | - Xiaojiang Xu
- Department of Pathology and Laboratory Medicine, Tulane University School of Medicine, New Orleans, LA, USA
| | - Jing Cao
- Department of Pathology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Xiaoying Wang
- Clinical Neuroscience Research Center, Department of Neurosurgery and Neurology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Bo Ning
- Center for Cellular and Molecular Diagnostics, Tulane University School of Medicine, New Orleans, LA, USA
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Ning Liu
- Clinical Neuroscience Research Center, Department of Neurosurgery and Neurology, Tulane University School of Medicine, New Orleans, LA, USA.
- Tulane University Translational Sciences Institute, New Orleans, LA, USA.
| | - Jia Fan
- Center for Cellular and Molecular Diagnostics, Tulane University School of Medicine, New Orleans, LA, USA.
- Department of Biochemistry and Molecular Biology, Tulane University School of Medicine, New Orleans, LA, USA.
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2
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Longfield SF, Gormal RS, Feller M, Parutto P, Reingruber J, Wallis TP, Joensuu M, Augustine GJ, Martínez-Mármol R, Holcman D, Meunier FA. Synapsin 2a tetramerisation selectively controls the presynaptic nanoscale organisation of reserve synaptic vesicles. Nat Commun 2024; 15:2217. [PMID: 38472171 PMCID: PMC10933366 DOI: 10.1038/s41467-024-46256-1] [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: 03/22/2023] [Accepted: 02/21/2024] [Indexed: 03/14/2024] Open
Abstract
Neurotransmitter release relies on the regulated fusion of synaptic vesicles (SVs) that are tightly packed within the presynaptic bouton of neurons. The mechanism by which SVs are clustered at the presynapse, while preserving their ability to dynamically recycle to support neuronal communication, remains unknown. Synapsin 2a (Syn2a) tetramerization has been suggested as a potential clustering mechanism. Here, we used Dual-pulse sub-diffractional Tracking of Internalised Molecules (DsdTIM) to simultaneously track single SVs from the recycling and the reserve pools, in live hippocampal neurons. The reserve pool displays a lower presynaptic mobility compared to the recycling pool and is also present in the axons. Triple knockout of Synapsin 1-3 genes (SynTKO) increased the mobility of reserve pool SVs. Re-expression of wild-type Syn2a (Syn2aWT), but not the tetramerization-deficient mutant K337Q (Syn2aK337Q), fully rescued these effects. Single-particle tracking revealed that Syn2aK337QmEos3.1 exhibited altered activity-dependent presynaptic translocation and nanoclustering. Therefore, Syn2a tetramerization controls its own presynaptic nanoclustering and thereby contributes to the dynamic immobilisation of the SV reserve pool.
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Affiliation(s)
- Shanley F Longfield
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Rachel S Gormal
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Matis Feller
- Group of Data Modelling and Computational Biology, IBENS, Ecole Normale Superieure, 75005, Paris, France
| | - Pierre Parutto
- Group of Data Modelling and Computational Biology, IBENS, Ecole Normale Superieure, 75005, Paris, France
| | - Jürgen Reingruber
- Group of Data Modelling and Computational Biology, IBENS, Ecole Normale Superieure, 75005, Paris, France
| | - Tristan P Wallis
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - Merja Joensuu
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
- Australian Institute for Bioengineering and Nanotechnology, The University of Queensland, Brisbane, QLD 4072, Australia
| | | | - Ramón Martínez-Mármol
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia
| | - David Holcman
- Group of Data Modelling and Computational Biology, IBENS, Ecole Normale Superieure, 75005, Paris, France
- Department of Applied Mathematics and Theoretical Physics (DAMPT) visitor, University of Cambridge, and Churchill College, CB30DS, Cambridge, UK
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, QLD 4072, Australia.
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD 4072, Australia.
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3
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Forte N, Nicois A, Marfella B, Mavaro I, D'Angelo L, Piscitelli F, Scandurra A, De Girolamo P, Baldelli P, Benfenati F, Di Marzo V, Cristino L. Early endocannabinoid-mediated depolarization-induced suppression of excitation delays the appearance of the epileptic phenotype in synapsin II knockout mice. Cell Mol Life Sci 2024; 81:37. [PMID: 38214769 PMCID: PMC11072294 DOI: 10.1007/s00018-023-05029-7] [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: 06/13/2023] [Revised: 10/16/2023] [Accepted: 10/31/2023] [Indexed: 01/13/2024]
Abstract
The mechanism underlying the transition from the pre-symptomatic to the symptomatic state is a crucial aspect of epileptogenesis. SYN2 is a member of a multigene family of synaptic vesicle phosphoproteins playing a fundamental role in controlling neurotransmitter release. Human SYN2 gene mutations are associated with epilepsy and autism spectrum disorder. Mice knocked out for synapsin II (SynII KO) are prone to epileptic seizures that appear after 2 months of age. However, the involvement of the endocannabinoid system, known to regulate seizure development and propagation, in the modulation of the excitatory/inhibitory balance in the epileptic hippocampal network of SynII KO mice has not been explored. In this study, we investigated the impact of endocannabinoids on glutamatergic and GABAergic synapses at hippocampal dentate gyrus granule cells in young pre-symptomatic (1-2 months old) and adult symptomatic (5-8 months old) SynII KO mice. We observed an increase in endocannabinoid-mediated depolarization-induced suppression of excitation in young SynII KO mice, compared to age-matched wild-type controls. In contrast, the endocannabinoid-mediated depolarization-induced suppression of inhibition remained unchanged in SynII KO mice at both ages. This selective alteration of excitatory synaptic transmission was accompanied by changes in hippocampal endocannabinoid levels and cannabinoid receptor type 1 distribution among glutamatergic and GABAergic synaptic terminals contacting the granule cells of the dentate gyrus. Finally, inhibition of type-1 cannabinoid receptors in young pre-symptomatic SynII KO mice induced seizures during a tail suspension test. Our results suggest that endocannabinoids contribute to maintaining network stability in a genetic mouse model of human epilepsy.
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Affiliation(s)
- Nicola Forte
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy
| | - Alessandro Nicois
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy
| | - Brenda Marfella
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy
| | - Isabella Mavaro
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy
| | - Livia D'Angelo
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Fabiana Piscitelli
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy
| | - Anna Scandurra
- Department of Biology, University of Naples Federico II, Naples, Italy
| | - Paolo De Girolamo
- Department of Veterinary Medicine and Animal Production, University of Naples Federico II, Naples, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Vincenzo Di Marzo
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy.
- Faculty of Medicine and Faculty of Agricultural and Food Sciences, Canada Excellence Research Chair on the Microbiome-Endocannabinoidome Axis in Metabolic Health, Université Laval, Québec City, QC, Canada.
- Heart and Lung Research Institute of Université Laval, Québec City, QC, Canada.
- Institute for Nutrition and Functional Foods, Centre NUTRISS, Université Laval, Québec City, QC, Canada.
| | - Luigia Cristino
- Institute of Biomolecular Chemistry, National Research Council of Italy, Pozzuoli (NA), Italy.
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4
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Michetti C, Ferrante D, Parisi B, Ciano L, Prestigio C, Casagrande S, Martinoia S, Terranova F, Millo E, Valente P, Giovedi' S, Benfenati F, Baldelli P. Low glycemic index diet restrains epileptogenesis in a gender-specific fashion. Cell Mol Life Sci 2023; 80:356. [PMID: 37947886 PMCID: PMC10638170 DOI: 10.1007/s00018-023-04988-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 09/25/2023] [Accepted: 09/27/2023] [Indexed: 11/12/2023]
Abstract
Dietary restriction, such as low glycemic index diet (LGID), have been successfully used to treat drug-resistant epilepsy. However, if such diet could also counteract antiepileptogenesis is still unclear. Here, we investigated whether the administration of LGID during the latent pre-epileptic period, prevents or delays the appearance of the overt epileptic phenotype. To this aim, we used the Synapsin II knockout (SynIIKO) mouse, a model of temporal lobe epilepsy in which seizures manifest 2-3 months after birth, offering a temporal window in which LGID may affect epileptogenesis. Pregnant SynIIKO mice were fed with either LGID or standard diet during gestation and lactation. Both diets were maintained in weaned mice up to 5 months of age. LGID delayed the seizure onset and induced a reduction of seizures severity only in female SynIIKO mice. In parallel with the epileptic phenotype, high-density multielectrode array recordings revealed a reduction of frequency, amplitude, duration, velocity of propagation and spread of interictal events by LGID in the hippocampus of SynIIKO females, but not mutant males, confirming the gender-specific effect. ELISA-based analysis revealed that LGID increased cortico-hippocampal allopregnanolone (ALLO) levels only in females, while it was unable to affect ALLO plasma concentrations in either sex. The results indicate that the gender-specific interference of LGID with the epileptogenic process can be ascribed to a gender-specific increase in cortical ALLO, a neurosteroid known to strengthen GABAergic transmission. The study highlights the possibility of developing a personalized gender-based therapy for temporal lobe epilepsy.
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Affiliation(s)
- Caterina Michetti
- Department of Experimental Medicine, University of Genova, Genoa, Italy.
- Center for Synaptic Neuroscience and Technology, Italian Institute of Technology, Genoa, Italy.
| | - Daniele Ferrante
- Department of Experimental Medicine, University of Genova, Genoa, Italy
| | - Barbara Parisi
- Department of Experimental Medicine, University of Genova, Genoa, Italy
| | - Lorenzo Ciano
- Department of Experimental Medicine, University of Genova, Genoa, Italy
- Center for Synaptic Neuroscience and Technology, Italian Institute of Technology, Genoa, Italy
| | - Cosimo Prestigio
- Department of Experimental Medicine, University of Genova, Genoa, Italy
| | - Silvia Casagrande
- Department of Experimental Medicine, University of Genova, Genoa, Italy
| | - Sergio Martinoia
- Department of Informatics, Bioengineering, Robotics and System Engineering, University of Genova, Genoa, Italy
| | - Fabio Terranova
- Department of Informatics, Bioengineering, Robotics and System Engineering, University of Genova, Genoa, Italy
| | - Enrico Millo
- Department of Experimental Medicine, University of Genova, Genoa, Italy
| | - Pierluigi Valente
- Department of Experimental Medicine, University of Genova, Genoa, Italy
- IRCCS, Ospedale Policlinico San Martino, Genoa, Italy
| | - Silvia Giovedi'
- Department of Experimental Medicine, University of Genova, Genoa, Italy
- IRCCS, Ospedale Policlinico San Martino, Genoa, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Italian Institute of Technology, Genoa, Italy
- IRCCS, Ospedale Policlinico San Martino, Genoa, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genova, Genoa, Italy.
- IRCCS, Ospedale Policlinico San Martino, Genoa, Italy.
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5
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Song SH, Augustine GJ. Different mechanisms of synapsin-induced vesicle clustering at inhibitory and excitatory synapses. Cell Rep 2023; 42:113004. [PMID: 37597184 DOI: 10.1016/j.celrep.2023.113004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 06/26/2023] [Accepted: 08/02/2023] [Indexed: 08/21/2023] Open
Abstract
Synapsins cluster synaptic vesicles (SVs) to provide a reserve pool (RP) of SVs that maintains synaptic transmission during sustained activity. However, it is unclear how synapsins cluster SVs. Here we show that either liquid-liquid phase separation (LLPS) or tetramerization-dependent cross-linking can cluster SVs, depending on whether a synapse is excitatory or inhibitory. Cell-free reconstitution reveals that both mechanisms can cluster SVs, with tetramerization being more effective. At inhibitory synapses, perturbing synapsin-dependent LLPS impairs SV clustering and synchronization of gamma-aminobutyric acid (GABA) release, while preventing synapsin tetramerization does not. At glutamatergic synapses, the opposite is true: synapsin tetramerization enhances clustering of glutamatergic SVs and mobilization of these SVs from the RP, while synapsin LLPS does not. Comparison of inhibitory and excitatory transmission during prolonged synaptic activity reveals that synapsin LLPS serves as a brake to limit GABA release, while synapsin tetramerization enables rapid mobilization of SVs from the RP to sustain glutamate release.
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Affiliation(s)
- Sang-Ho Song
- Neuroscience and Mental Health Program, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
| | - George J Augustine
- Neuroscience and Mental Health Program, Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore.
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6
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Nikolic A, Maule F, Bobyn A, Ellestad K, Paik S, Marhon SA, Mehdipour P, Lun X, Chen HM, Mallard C, Hay AJ, Johnston MJ, Gafuik CJ, Zemp FJ, Shen Y, Ninkovic N, Osz K, Labit E, Berger ND, Brownsey DK, Kelly JJ, Biernaskie J, Dirks PB, Derksen DJ, Jones SJM, Senger DL, Chan JA, Mahoney DJ, De Carvalho DD, Gallo M. macroH2A2 antagonizes epigenetic programs of stemness in glioblastoma. Nat Commun 2023; 14:3062. [PMID: 37244935 DOI: 10.1038/s41467-023-38919-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Accepted: 05/22/2023] [Indexed: 05/29/2023] Open
Abstract
Self-renewal is a crucial property of glioblastoma cells that is enabled by the choreographed functions of chromatin regulators and transcription factors. Identifying targetable epigenetic mechanisms of self-renewal could therefore represent an important step toward developing effective treatments for this universally lethal cancer. Here we uncover an epigenetic axis of self-renewal mediated by the histone variant macroH2A2. With omics and functional assays deploying patient-derived in vitro and in vivo models, we show that macroH2A2 shapes chromatin accessibility at enhancer elements to antagonize transcriptional programs of self-renewal. macroH2A2 also sensitizes cells to small molecule-mediated cell death via activation of a viral mimicry response. Consistent with these results, our analyses of clinical cohorts indicate that high transcriptional levels of this histone variant are associated with better prognosis of high-grade glioma patients. Our results reveal a targetable epigenetic mechanism of self-renewal controlled by macroH2A2 and suggest additional treatment approaches for glioblastoma patients.
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Affiliation(s)
- Ana Nikolic
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Francesca Maule
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Anna Bobyn
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Biological Sciences, Faculty of Science, University of Calgary, Calgary, AB, Canada
| | - Katrina Ellestad
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Seungil Paik
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | | | - Parinaz Mehdipour
- Princess Margaret Cancer Centre, Toronto, ON, Canada
- Ludwig Institute for Cancer Research, University of Oxford, Oxford, UK
| | - Xueqing Lun
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Huey-Miin Chen
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Claire Mallard
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Alexander J Hay
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Michael J Johnston
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Christopher J Gafuik
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Franz J Zemp
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Yaoqing Shen
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, BC, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Nicoletta Ninkovic
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Katalin Osz
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Elodie Labit
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Compararive Biology and Experimental Medicine, Faculty of Veterinary Medicine, and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - N Daniel Berger
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Duncan K Brownsey
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Chemistry, Faculty of Science, University of Calgary, Calgary, AB, Canada
| | - John J Kelly
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Clinical Neurosciences, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Jeff Biernaskie
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Compararive Biology and Experimental Medicine, Faculty of Veterinary Medicine, and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Peter B Dirks
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Darren J Derksen
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Chemistry, Faculty of Science, University of Calgary, Calgary, AB, Canada
| | - Steven J M Jones
- Canada's Michael Smith Genome Sciences Centre, BC Cancer, Vancouver, BC, Canada
- Department of Medical Genetics, University of British Columbia, Vancouver, BC, Canada
| | - Donna L Senger
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Jennifer A Chan
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Oncology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Douglas J Mahoney
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
- Department of Microbiology, Immunology and Infectious Diseases, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
| | - Daniel D De Carvalho
- Princess Margaret Cancer Centre, Toronto, ON, Canada
- Department of Medical Biophysics, Faculty of Science, University of Toronto, Toronto, ON, Canada
| | - Marco Gallo
- Arnie Charbonneau Cancer Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
- Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
- Department of Biochemistry and Molecular Biology, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada.
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7
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Chiantia G, Hidisoglu E, Marcantoni A. The Role of Ryanodine Receptors in Regulating Neuronal Activity and Its Connection to the Development of Alzheimer's Disease. Cells 2023; 12:cells12091236. [PMID: 37174636 PMCID: PMC10177020 DOI: 10.3390/cells12091236] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 04/19/2023] [Accepted: 04/21/2023] [Indexed: 05/15/2023] Open
Abstract
Research into the early impacts of Alzheimer's disease (AD) on synapse function is one of the most promising approaches to finding a treatment. In this context, we have recently demonstrated that the Abeta42 peptide, which builds up in the brain during the processing of the amyloid precursor protein (APP), targets the ryanodine receptors (RyRs) of mouse hippocampal neurons and potentiates calcium (Ca2+) release from the endoplasmic reticulum (ER). The uncontrolled increase in intracellular calcium concentration ([Ca2+]i), leading to the development of Ca2+ dysregulation events and related excitable and synaptic dysfunctions, is a consolidated hallmark of AD onset and possibly other neurodegenerative diseases. Since RyRs contribute to increasing [Ca2+]i and are thought to be a promising target for AD treatment, the goal of this review is to summarize the current level of knowledge regarding the involvement of RyRs in governing neuronal function both in physiological conditions and during the onset of AD.
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Affiliation(s)
| | - Enis Hidisoglu
- Department of Drug and Science Technology, University of Torino, Corso Raffaello 30, 10125 Torino, Italy
| | - Andrea Marcantoni
- Department of Drug and Science Technology, University of Torino, Corso Raffaello 30, 10125 Torino, Italy
- N.I.S. Center, University of Torino, 10125 Turin, Italy
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8
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Hidisoglu E, Chiantia G, Franchino C, Tomagra G, Giustetto M, Carbone E, Carabelli V, Marcantoni A. The ryanodine receptor-calstabin interaction stabilizer S107 protects hippocampal neurons from GABAergic synaptic alterations induced by Abeta42 oligomers. J Physiol 2022; 600:5295-5309. [PMID: 36284365 DOI: 10.1113/jp283537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Accepted: 10/12/2022] [Indexed: 01/05/2023] Open
Abstract
The oligomeric form of the peptide amyloid beta 42 (Abeta42) contributes to the development of synaptic abnormalities and cognitive impairments associated with Alzheimer's disease (AD). To date, there is a gap in knowledge regarding how Abeta42 alters the elementary parameters of GABAergic synaptic function. Here we found that Abeta42 increased the frequency and amplitude of miniature GABAergic currents as well as the amplitude of evoked inhibitory postsynaptic currents. When we focused on paired pulse depression (PPD) to establish whether GABA release probability was affected by Abeta42, we did not observe any significant change. On the other hand, a more detailed investigation of the presynaptic effects induced by Abeta42 by means of multiple probability fluctuation analysis and cumulative amplitude analysis showed an increase in both the size of the readily releasable pool responsible for synchronous release and the number of release sites. We further explored whether ryanodine receptors (RyRs) contributed to exacerbating these changes by stabilizing the interaction between RyRs and the accessory protein calstabin. We observed that the RyR-calstabin interaction stabilizer S107 restored the synaptic parameters to values comparable to those measured in control conditions. In conclusion, our results clarify the mechanisms of potentiation of GABAergic synapses induced by Abeta42. We further suggest that RyRs are involved in the control of synaptic activity during the early stage of AD onset and that their stabilization could represent a new therapeutical approach for AD treatment. KEY POINTS: Accumulation of the peptide amyloid beta 42 (Abeta42) is a key characteristic of Alzheimer's disease (AD) and causes synaptic dysfunctions. To date, the effects of Abeta42 accumulation on GABAergic synapses are poorly understood. The findings reported here suggest that, similarly to what is observed on glutamatergic synapses, Abeta42 modifies GABAergic synapses by targeting ryanodine receptors and causing calcium dysregulation. The GABAergic impairments can be restored by the ryanodine receptor-calstabin interaction stabilizer S107. Based on this research, RyRs stabilization may represent a novel pharmaceutical strategy for preventing or delaying AD.
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Affiliation(s)
- Enis Hidisoglu
- Department of Drug Science and Technology, NIS Centre, University of Turin, Turin, Italy
| | | | - Claudio Franchino
- Department of Drug Science and Technology, NIS Centre, University of Turin, Turin, Italy
| | - Giulia Tomagra
- Department of Drug Science and Technology, NIS Centre, University of Turin, Turin, Italy
| | | | - Emilio Carbone
- Department of Drug Science and Technology, NIS Centre, University of Turin, Turin, Italy
| | - Valentina Carabelli
- Department of Drug Science and Technology, NIS Centre, University of Turin, Turin, Italy
| | - Andrea Marcantoni
- Department of Drug Science and Technology, NIS Centre, University of Turin, Turin, Italy
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9
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Michetti C, Falace A, Benfenati F, Fassio A. Synaptic genes and neurodevelopmental disorders: From molecular mechanisms to developmental strategies of behavioral testing. Neurobiol Dis 2022; 173:105856. [PMID: 36070836 DOI: 10.1016/j.nbd.2022.105856] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 08/29/2022] [Accepted: 08/30/2022] [Indexed: 10/14/2022] Open
Abstract
Synaptopathies are a class of neurodevelopmental disorders caused by modification in genes coding for synaptic proteins. These proteins oversee the process of neurotransmission, mainly controlling the fusion and recycling of synaptic vesicles at the presynaptic terminal, the expression and localization of receptors at the postsynapse and the coupling between the pre- and the postsynaptic compartments. Murine models, with homozygous or heterozygous deletion for several synaptic genes or knock-in for specific pathogenic mutations, have been developed. They have proved to be extremely informative for understanding synaptic physiology, as well as for clarifying the patho-mechanisms leading to developmental delay, epilepsy and motor, cognitive and social impairments that are the most common clinical manifestations of neurodevelopmental disorders. However, the onset of these disorders emerges during infancy and adolescence while the behavioral phenotyping is often conducted in adult mice, missing important information about the impact of synaptic development and maturation on the manifestation of the behavioral phenotype. Here, we review the main achievements obtained by behavioral testing in murine models of synaptopathies and propose a battery of behavioral tests to improve classification, diagnosis and efficacy of potential therapeutic treatments. Our aim is to underlie the importance of studying behavioral development and better focusing on disease onset and phenotypes.
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Affiliation(s)
- Caterina Michetti
- Department of Experimental Medicine, University of Genoa, Genoa, Italy; Center for Synaptic Neuroscience, Istituto Italiano di Tecnologia, Genoa, Italy.
| | - Antonio Falace
- Pediatric Neurology, Neurogenetics and Neurobiology Unit and Laboratories, Children's Hospital A. Meyer-University of Florence, Florence, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience, Istituto Italiano di Tecnologia, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Anna Fassio
- Department of Experimental Medicine, University of Genoa, Genoa, Italy; IRCCS Ospedale Policlinico San Martino, Genoa, Italy.
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10
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The Genomic Architecture of Pregnancy-Associated Plasticity in the Maternal Mouse Hippocampus. eNeuro 2022; 9:ENEURO.0117-22.2022. [PMID: 36239981 PMCID: PMC9522463 DOI: 10.1523/eneuro.0117-22.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 08/10/2022] [Accepted: 08/25/2022] [Indexed: 12/15/2022] Open
Abstract
Pregnancy is associated with extraordinary plasticity in the maternal brain. Studies in humans and other mammals suggest extensive structural and functional remodeling of the female brain during and after pregnancy. However, we understand remarkably little about the molecular underpinnings of this natural phenomenon. To gain insight into pregnancy-associated hippocampal plasticity, we performed single nucleus RNA sequencing (snRNA-seq) and snATAC-seq from the mouse hippocampus before, during, and after pregnancy. We identified cell type-specific transcriptional and epigenetic signatures associated with pregnancy and postpartum adaptation. In addition, we analyzed receptor-ligand interactions and transcription factor (TF) motifs that inform hippocampal cell type identity and provide evidence of pregnancy-associated adaption. In total, these data provide a unique resource of coupled transcriptional and epigenetic data across a dynamic time period in the mouse hippocampus and suggest opportunities for functional interrogation of hormone-mediated plasticity.
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11
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Leung HW, Foo G, VanDongen A. Arc Regulates Transcription of Genes for Plasticity, Excitability and Alzheimer’s Disease. Biomedicines 2022; 10:biomedicines10081946. [PMID: 36009494 PMCID: PMC9405677 DOI: 10.3390/biomedicines10081946] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 07/21/2022] [Accepted: 07/25/2022] [Indexed: 02/06/2023] Open
Abstract
The immediate early gene Arc is a master regulator of synaptic function and a critical determinant of memory consolidation. Here, we show that Arc interacts with dynamic chromatin and closely associates with histone markers for active enhancers and transcription in cultured rat hippocampal neurons. Both these histone modifications, H3K27Ac and H3K9Ac, have recently been shown to be upregulated in late-onset Alzheimer’s disease (AD). When Arc induction by pharmacological network activation was prevented using a short hairpin RNA, the expression profile was altered for over 1900 genes, which included genes associated with synaptic function, neuronal plasticity, intrinsic excitability, and signalling pathways. Interestingly, about 100 Arc-dependent genes are associated with the pathophysiology of AD. When endogenous Arc expression was induced in HEK293T cells, the transcription of many neuronal genes was increased, suggesting that Arc can control expression in the absence of activated signalling pathways. Taken together, these data establish Arc as a master regulator of neuronal activity-dependent gene expression and suggest that it plays a significant role in the pathophysiology of AD.
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Affiliation(s)
| | - Gabriel Foo
- Duke-NUS Medical School, Singapore 169857, Singapore
| | - Antonius VanDongen
- Duke-NUS Medical School, Singapore 169857, Singapore
- Department of Pharmacology and Cancer Biology, Duke University, Durham, NC 27710, USA
- Correspondence:
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12
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Invertebrate neurons as a simple model to study the hyperexcitable state of epileptic disorders in single cells, monosynaptic connections, and polysynaptic circuits. Biophys Rev 2022; 14:553-568. [PMID: 35528035 PMCID: PMC9043075 DOI: 10.1007/s12551-022-00942-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Accepted: 03/09/2022] [Indexed: 12/17/2022] Open
Abstract
Epilepsy is a neurological disorder characterized by a hyperexcitable state in neurons from different brain regions. Much is unknown about epilepsy and seizures development, depicting a growing field of research. Animal models have provided important clues about the underlying mechanisms of seizure-generating neuronal circuits. Mammalian complexity still makes it difficult to define some principles of nervous system function, and non-mammalian models have played pivotal roles depending on the research question at hand. Mollusks and the Helix land snail have been used to study epileptic-like behavior in neurons. Neurons from these organisms confer advantages as single-cell identification, isolation, and culture, either as single cells or as physiological relevant monosynaptic or polysynaptic circuits, together with amenability to different protocols and treatments. This review's purpose consists in presenting relevant papers in order to gain a better understanding of Helix neurons, their characteristics, uses, and capabilities for studying the fundamental mechanisms of epileptic disorders and their treatment, to facilitate their more expansive use in epilepsy research.
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13
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Schwark R, Andrade R, Bykhovskaia M. Synapsin II Directly Suppresses Epileptic Seizures In Vivo. Brain Sci 2022; 12:brainsci12030325. [PMID: 35326282 PMCID: PMC8946686 DOI: 10.3390/brainsci12030325] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2022] [Revised: 02/22/2022] [Accepted: 02/24/2022] [Indexed: 11/21/2022] Open
Abstract
The synapsin family offers a strong linkage between synaptic mechanisms and the epileptic phenotype. Synapsins are phosphoproteins reversibly associated with synaptic vesicles. Synapsin deficiency can cause epilepsy in humans, and synapsin II (SynII) in knockout (KO) mice causes generalized epileptic seizures. To differentiate between the direct effect of SynII versus its secondary adaptations, we used neonatal intracerebroventricular injections of the adeno-associated virus (AAV) expressing SynII. We found that SynII reintroduction diminished the enhanced synaptic activity in Syn2 KO hippocampal slices. Next, we employed the epileptogenic agent 4-aminopyridine (4-AP) and found that SynII reintroduction completely rescued the epileptiform activity observed in Syn2 KO slices upon 4-AP application. Finally, we developed a protocol to provoke behavioral seizures in young Syn2 KO animals and found that SynII reintroduction balances the behavioral seizures. To elucidate the mechanisms through which SynII suppresses hyperexcitability, we injected the phospho-incompetent version of Syn2 that had the mutated protein kinase A (PKA) phosphorylation site. The introduction of the phospho-incompetent SynII mutant suppressed the epileptiform and seizure activity in Syn2 KO mice, but not to the extent observed upon the reintroduction of native SynII. These findings show that SynII can directly suppress seizure activity and that PKA phosphorylation contributes to this function.
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Affiliation(s)
- Ryan Schwark
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI 48203, USA;
- The Zuckerman Institute, Columbia University, New York, NY 10027, USA
| | - Rodrigo Andrade
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI 48203, USA;
| | - Maria Bykhovskaia
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI 48203, USA;
- Correspondence:
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14
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Beretta S, Gritti L, Ponzoni L, Scalmani P, Mantegazza M, Sala M, Verpelli C, Sala C. Rescuing epileptic and behavioral alterations in a Dravet syndrome mouse model by inhibiting eukaryotic elongation factor 2 kinase (eEF2K). Mol Autism 2022; 13:1. [PMID: 34980259 PMCID: PMC8722032 DOI: 10.1186/s13229-021-00484-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 12/23/2021] [Indexed: 11/30/2022] Open
Abstract
Background Dravet Syndrome is a severe childhood pharmaco-resistant epileptic disorder mainly caused by mutations in the SCN1A gene, which encodes for the α1 subunit of the type I voltage-gated sodium channel (NaV1.1), that causes imbalance between excitation and inhibition in the brain. We recently found that eEF2K knock out mice displayed enhanced GABAergic transmission and tonic inhibition and were less susceptible to epileptic seizures. Thus, we investigated the effect of inhibition of eEF2K on the epileptic and behavioral phenotype of Scn1a ± mice, a murine model of Dravet Syndrome. Methods To elucidate the role of eEF2K pathway in the etiopathology of Dravet syndrome we generated a new mouse model deleting the eEF2K gene in Scn1a ± mice. By crossing Scn1a ± mice with eEF2K−/− mice we obtained the three main genotypes needed for our studies, Scn1a+/+ eEF2K+/+ (WT mice), Scn1a ± eEF2K+/+ mice (Scn1a ± mice) and Scn1a ± eEF2K−/− mice, that were fully characterized for EEG and behavioral phenotype. Furthermore, we tested the ability of a pharmacological inhibitor of eEF2K in rescuing EEG alterations of the Scn1a ± mice. Results We showed that the activity of eEF2K/eEF2 pathway was enhanced in Scn1a ± mice. Then, we demonstrated that both genetic deletion and pharmacological inhibition of eEF2K were sufficient to ameliorate the epileptic phenotype of Scn1a ± mice. Interestingly we also found that motor coordination defect, memory impairments, and stereotyped behavior of the Scn1a ± mice were reverted by eEF2K deletion. The analysis of spontaneous inhibitory postsynaptic currents (sIPSCs) suggested that the rescue of the pathological phenotype was driven by the potentiation of GABAergic synapses. Limitations Even if we found that eEF2K deletion was able to increase inhibitory synapses function, the molecular mechanism underlining the inhibition of eEF2K/eEF2 pathway in rescuing epileptic and behavioral alterations in the Scn1a ± needs further investigations. Conclusions Our data indicate that pharmacological inhibition of eEF2K could represent a novel therapeutic intervention for treating epilepsy and related comorbidities in the Dravet syndrome. Supplementary Information The online version contains supplementary material available at 10.1186/s13229-021-00484-0.
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Affiliation(s)
- Stefania Beretta
- CNR Neuroscience Institute, Milan, and NeuroMi Milan Center for Neuroscience, Via Raoul Follereau 3, 20854, Vedano al Lambro, MB, Italy
| | - Laura Gritti
- CNR Neuroscience Institute, Milan, and NeuroMi Milan Center for Neuroscience, Via Raoul Follereau 3, 20854, Vedano al Lambro, MB, Italy
| | - Luisa Ponzoni
- CNR Neuroscience Institute, Milan, and NeuroMi Milan Center for Neuroscience, Via Raoul Follereau 3, 20854, Vedano al Lambro, MB, Italy
| | - Paolo Scalmani
- L'Unità Operativa Complessa di Epilettologia Clinica e Sperimentale, Foundation Istituto di Ricerca e Cura a Carattere Scientifico (IRCCS), Neurological Institute Carlo Besta, 20133, Milan, Italy
| | - Massimo Mantegazza
- CNRS UMR 7275, Institut National de La Santé Et de La Recherche Médicale, LabEx ICST, Institute of Molecular and Cellular Pharmacology (IPMC), Université Côte d'Azur (UCA), 06560, Valbonne-Sophia Antipolis, France
| | - Mariaelvina Sala
- CNR Neuroscience Institute, Milan, and NeuroMi Milan Center for Neuroscience, Via Raoul Follereau 3, 20854, Vedano al Lambro, MB, Italy
| | - Chiara Verpelli
- CNR Neuroscience Institute, Milan, and NeuroMi Milan Center for Neuroscience, Via Raoul Follereau 3, 20854, Vedano al Lambro, MB, Italy.
| | - Carlo Sala
- CNR Neuroscience Institute, Milan, and NeuroMi Milan Center for Neuroscience, Via Raoul Follereau 3, 20854, Vedano al Lambro, MB, Italy.
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15
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Moschetta M, Ravasenga T, De Fusco A, Maragliano L, Aprile D, Orlando M, Sacchetti S, Casagrande S, Lignani G, Fassio A, Baldelli P, Benfenati F. Ca 2+ binding to synapsin I regulates resting Ca 2+ and recovery from synaptic depression in nerve terminals. Cell Mol Life Sci 2022; 79:600. [PMID: 36409372 PMCID: PMC9678998 DOI: 10.1007/s00018-022-04631-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Revised: 10/23/2022] [Accepted: 11/13/2022] [Indexed: 11/22/2022]
Abstract
Synapsin I (SynI) is a synaptic vesicle (SV)-associated phosphoprotein that modulates neurotransmission by controlling SV trafficking. The SynI C-domain contains a highly conserved ATP binding site mediating SynI oligomerization and SV clustering and an adjacent main Ca2+ binding site, whose physiological role is unexplored. Molecular dynamics simulations revealed that the E373K point mutation irreversibly deletes Ca2+ binding to SynI, still allowing ATP binding, but inducing a destabilization of the SynI oligomerization interface. Here, we analyzed the effects of this mutation on neurotransmitter release and short-term plasticity in excitatory and inhibitory synapses from primary hippocampal neurons. Patch-clamp recordings showed an increase in the frequency of miniature excitatory postsynaptic currents (EPSCs) that was totally occluded by exogenous Ca2+ chelators and associated with a constitutive increase in resting terminal Ca2+ concentrations. Evoked EPSC amplitude was also reduced, due to a decreased readily releasable pool (RRP) size. Moreover, in both excitatory and inhibitory synapses, we observed a marked impaired recovery from synaptic depression, associated with impaired RRP refilling and depletion of the recycling pool of SVs. Our study identifies SynI as a novel Ca2+ buffer in excitatory terminals. Blocking Ca2+ binding to SynI results in higher constitutive Ca2+ levels that increase the probability of spontaneous release and disperse SVs. This causes a decreased size of the RRP and an impaired recovery from depression due to the failure of SV reclustering after sustained high-frequency stimulation. The results indicate a physiological role of Ca2+ binding to SynI in the regulation of SV clustering and trafficking in nerve terminals.
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Affiliation(s)
- Matteo Moschetta
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy
| | - Tiziana Ravasenga
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
| | - Antonio De Fusco
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy
| | - Luca Maragliano
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,Department of Life and Environmental Sciences, Polytechnic University of Marche, Via Brecce Bianche, 60131 Ancona, Italy
| | - Davide Aprile
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy ,Present Address: High-Definition Disease Modelling Lab, Campus IFOM-IEO, Milan, Italy
| | - Marta Orlando
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,Present Address: Charitè Universitätsmedizin Berlin, Freie Universität Berlin and Humboldt-Universität Zu Berlin, Berlin Institute of Health, NeuroCure Cluster of Excellence, Berlin, Germany
| | - Silvio Sacchetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy
| | - Silvia Casagrande
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy
| | - Gabriele Lignani
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,Present Address: Queens Square Institute of Neurology, University College London, London, UK
| | - Anna Fassio
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genoa, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano Di Tecnologia, Largo Rosanna Benzi 10, 16132 Genoa, Italy ,IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genoa, Italy
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16
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Ruiter M, Herstel LJ, Wierenga CJ. Reduction of Dendritic Inhibition in CA1 Pyramidal Neurons in Amyloidosis Models of Early Alzheimer's Disease. J Alzheimers Dis 2021; 78:951-964. [PMID: 33074225 PMCID: PMC7739974 DOI: 10.3233/jad-200527] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background: In an early stage of Alzheimer’s disease (AD), before the formation of amyloid plaques, neuronal network hyperactivity has been reported in both patients and animal models. This suggests an underlying disturbance of the balance between excitation and inhibition. Several studies have highlighted the role of somatic inhibition in early AD, while less is known about dendritic inhibition. Objective: In this study we investigated how inhibitory synaptic currents are affected by elevated Aβ levels. Methods: We performed whole-cell patch clamp recordings of CA1 pyramidal neurons in organotypic hippocampal slice cultures after treatment with Aβ-oligomers and in hippocampal brain slices from AppNL-F-G mice (APP-KI). Results: We found a reduction of spontaneous inhibitory postsynaptic currents (sIPSCs) in CA1 pyramidal neurons in organotypic slices after 24 h Aβ treatment. sIPSCs with slow rise times were reduced, suggesting a specific loss of dendritic inhibitory inputs. As miniature IPSCs and synaptic density were unaffected, these results suggest a decrease in activity-dependent transmission after Aβ treatment. We observed a similar, although weaker, reduction in sIPSCs in CA1 pyramidal neurons from APP-KI mice compared to control. When separated by sex, the strongest reduction in sIPSC frequency was found in slices from male APP-KI mice. Consistent with hyperexcitability in pyramidal cells, dendritically targeting interneurons received slightly more excitatory input. GABAergic action potentials had faster kinetics in APP-KI slices. Conclusion: Our results show that Aβ affects dendritic inhibition via impaired action potential driven release, possibly due to altered kinetics of GABAergic action potentials. Reduced dendritic inhibition may contribute to neuronal hyperactivity in early AD.
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Affiliation(s)
- Marvin Ruiter
- Department of Cell Biology, Neurobiology and Biophysics, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Lotte J Herstel
- Department of Cell Biology, Neurobiology and Biophysics, Faculty of Science, Utrecht University, Utrecht, The Netherlands
| | - Corette J Wierenga
- Department of Cell Biology, Neurobiology and Biophysics, Faculty of Science, Utrecht University, Utrecht, The Netherlands
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17
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Longhena F, Faustini G, Brembati V, Pizzi M, Benfenati F, Bellucci A. An updated reappraisal of synapsins: structure, function and role in neurological and psychiatric disorders. Neurosci Biobehav Rev 2021; 130:33-60. [PMID: 34407457 DOI: 10.1016/j.neubiorev.2021.08.011] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/29/2021] [Accepted: 08/09/2021] [Indexed: 01/02/2023]
Abstract
Synapsins (Syns) are phosphoproteins strongly involved in neuronal development and neurotransmitter release. Three distinct genes SYN1, SYN2 and SYN3, with elevated evolutionary conservation, have been described to encode for Synapsin I, Synapsin II and Synapsin III, respectively. Syns display a series of common features, but also exhibit distinctive localization, expression pattern, post-translational modifications (PTM). These characteristics enable their interaction with other synaptic proteins, membranes and cytoskeletal components, which is essential for the proper execution of their multiple functions in neuronal cells. These include the control of synapse formation and growth, neuron maturation and renewal, as well as synaptic vesicle mobilization, docking, fusion, recycling. Perturbations in the balanced expression of Syns, alterations of their PTM, mutations and polymorphisms of their encoding genes induce severe dysregulations in brain networks functions leading to the onset of psychiatric or neurological disorders. This review presents what we have learned since the discovery of Syn I in 1977, providing the state of the art on Syns structure, function, physiology and involvement in central nervous system disorders.
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Affiliation(s)
- Francesca Longhena
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Gaia Faustini
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Viviana Brembati
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Marina Pizzi
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
| | - Fabio Benfenati
- Italian Institute of Technology, Via Morego 30, Genova, Italy; IRCSS Policlinico San Martino Hospital, Largo Rosanna Benzi 10, 16132, Genova, Italy.
| | - Arianna Bellucci
- Division of Pharmacology, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy; Laboratory for Preventive and Personalized Medicine, Department of Molecular and Translational Medicine, University of Brescia, Viale Europa 11, 25123, Brescia, Italy.
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18
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Aguilar-Ordoñez I, Pérez-Villatoro F, García-Ortiz H, Barajas-Olmos F, Ballesteros-Villascán J, González-Buenfil R, Fresno C, Garcíarrubio A, Fernández-López JC, Tovar H, Hernández-Lemus E, Orozco L, Soberón X, Morett E. Whole genome variation in 27 Mexican indigenous populations, demographic and biomedical insights. PLoS One 2021; 16:e0249773. [PMID: 33831079 PMCID: PMC8031408 DOI: 10.1371/journal.pone.0249773] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Accepted: 03/24/2021] [Indexed: 12/12/2022] Open
Abstract
There has been limited study of Native American whole genome diversity to date, which impairs effective implementation of personalized medicine and a detailed description of its demographic history. Here we report high coverage whole genome sequencing of 76 unrelated individuals, from 27 indigenous groups across Mexico, with more than 97% average Native American ancestry. On average, each individual has 3.26 million Single Nucleotide Variants and short indels, that together comprise a catalog of 9,737,152 variants, 44,118 of which are novel. We report 497 common Single Nucleotide Variants (with allele frequency > 5%) mapped to drug responses and 316,577 in enhancer or promoter elements; interestingly we found some of these enhancer variants in PPARG, a nuclear receptor involved in highly prevalent health problems in Mexican population, such as obesity, diabetes, and insulin resistance. By detecting signals of positive selection we report 24 enriched key pathways under selection, most of them related to immune mechanisms. No missense variants in ACE2, the receptor responsible for the entry of the SARS CoV-2 virus, were found in any individual. Population genomics and phylogenetic analyses demonstrated stratification in a Northern-Central-Southern axis, with major substructure in the Central region. The Seri, a northern group with the most genetic divergence in our study, showed a distinctive genomic context with the most novel variants, and the most population specific genotypes. Genome-wide analysis showed that the average haplotype blocks are longer in Native Mexicans than in other world populations. With this dataset we describe previously undetected population level variation in Native Mexicans, helping to reduce the gap in genomic data representation of such groups.
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Affiliation(s)
- Israel Aguilar-Ordoñez
- Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
- Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, México
| | - Fernando Pérez-Villatoro
- Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
- Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, México
- Winter Genomics, Mexico City, México
| | | | | | | | - Ram González-Buenfil
- Benemérita Universidad Autónoma de Puebla (BUAP), Puebla de Zaragoza, Puebla, México
| | - Cristobal Fresno
- Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, México
| | - Alejandro Garcíarrubio
- Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
| | | | - Hugo Tovar
- Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, México
| | | | - Lorena Orozco
- Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, México
| | - Xavier Soberón
- Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
- Instituto Nacional de Medicina Genómica (INMEGEN), Mexico City, México
| | - Enrique Morett
- Instituto de Biotecnología, Universidad Nacional Autónoma de México (UNAM), Cuernavaca, Morelos, México
- * E-mail:
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19
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Giving names to the actors of synaptic transmission: The long journey from synaptic vesicles to neural plasticity. ADVANCES IN PHARMACOLOGY 2021; 90:19-37. [PMID: 33706933 DOI: 10.1016/bs.apha.2020.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
More than a scientific paper or a review article, this is a remembrance of a unique time of science and life that the authors spent in Paul Greengard's laboratory at the Rockefeller University in New York in the 1980s and 1990s, forming the so-called synaptic vesicle group. It was a time in which the molecular mechanisms of synaptic transmission and the nature of the organelles in charge of storing and releasing neurotransmitter were just beginning to be understood. It was an exciting time in which the protein composition of synaptic vesicles started to be identified. It turned out that the interactions of synaptic vesicle proteins with the cytoskeleton and the presynaptic membrane and their modulation by protein phosphorylation represented an essential network regulating the efficiency of neurotransmitter release and thereby synaptic strength and plasticity. This is also a description of the distinct scientific journeys that the three authors took on going back to Europe and how they were strongly influenced by the generous and outstanding mentorship of Paul Greengard, his genuine interest in their lives and careers and the life-long friendship with him.
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20
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Dysfunction of the serotonergic system in the brain of synapsin triple knockout mice is associated with behavioral abnormalities resembling synapsin-related human pathologies. Prog Neuropsychopharmacol Biol Psychiatry 2021; 105:110135. [PMID: 33058959 DOI: 10.1016/j.pnpbp.2020.110135] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/31/2020] [Accepted: 10/06/2020] [Indexed: 11/23/2022]
Abstract
Synapsins (Syns) are a family of phosphoproteins associated with synaptic vesicles (SVs). Their main function is to regulate neurotransmitter release by maintaining a reserve pool of SVs at the presynaptic terminal. Previous studies reported that the deletion of one or more Syn genes in mice results in an epileptic phenotype and autism-related behavioral abnormalities. Here we aimed at characterizing the behavioral phenotype and neurobiological correlates of the deletion of Syns in a Syn triple knockout (TKO) mouse model. Wild type (WT) and TKO mice were tested in the open field, novelty suppressed feeding, light-dark box, forced swim, tail suspension and three-chamber sociability tests. Using in vivo electrophysiology, we recorded the spontaneous activity of dorsal raphe nucleus (DRN) serotonin (5-HT) and ventral tegmental area (VTA) dopamine (DA) neurons. Levels of 5-HT and DA in the frontal cortex and hippocampus of WT and TKO mice were also assessed using a High-Performance Liquid Chromatography. TKO mice displayed hyperactivity and impaired social and anxiety-like behavior. Behavioral dysfunctions were accompanied by reduced firing activity of DRN 5-HT, but not VTA DA, neurons. TKO mice also showed increased responsiveness of DRN 5-HT-1A autoreceptors, measured as a reduced dose of the 5-HT-1A agonist 8-OH-DPAT necessary to inhibit DRN 5-HT firing activity by 50%. Finally, hippocampal 5-HT levels were lower in TKO than in WT mice. Overall, Syns deletion in mice leads to a reduction in DRN 5-HT firing activity and hippocampal 5-HT levels along with behavioral alterations reminiscent of human neuropsychiatric conditions associated with Syn dysfunction.
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21
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Shen W, Jin L, Zhu A, Lin Y, Pan G, Zhou S, Cheng J, Zhang J, Tu F, Liu C, Xie Q, Chen X. Treadmill exercise enhances synaptic plasticity in the ischemic penumbra of MCAO mice by inducing the expression of Camk2a via CYFIP1 upregulation. Life Sci 2021; 270:119033. [PMID: 33497737 DOI: 10.1016/j.lfs.2021.119033] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 12/29/2020] [Accepted: 01/01/2021] [Indexed: 10/22/2022]
Abstract
AIMS Physical exercise is beneficial to the recovery of patients with ischemic stroke. However, the underlying mechanism by which exercise promotes dendritic remodeling and synaptic plasticity is still obscure. This study explored the mechanism by which treadmill exercise enhances synaptic plasticity and dendritic remodeling in the ischemic penumbra. MAIN METHODS A middle cerebral artery occlusion (MCAO) model was generated in C57BL/6 mice, and lentivirus-mediated cytoplasmic FMRP-associated protein 1 (CYFIP1) shRNA expression was utilized to confirm the role of CYFIP1 in the exercise-induced increase in synaptic plasticity and dendritic remodeling. Neurological deficits were measured using the Zea Longa scale. Hematoxylin-eosin (H&E) staining and Nissl staining were performed to assess cerebral ischemic injury. Golgi-Cox staining was used to observe changes in dendritic remodeling and synaptic plasticity. Transmission electron microscopy (TEM) was performed to observe the synaptic ultrastructure. Molecular mechanisms were explored using immunofluorescence staining and western blotting. KEY FINDINGS Treadmill training enhanced synaptic plasticity in the penumbra. Additionally, we observed significant increases in the expression of CYFIP1 and calcium/calmodulin-dependent kinase 2a (Camk2a); enhanced neurological recovery and a decreased infarct volume. However, the injection of a lentivirus containing CYFIP1 shRNA into the lateral ventricle exerted negative effects on synaptic plasticity. Moreover, the exercise-induced neuroprotective effects were abolished by lentivirus-mediated CYFIP1 shRNA expression, consistent with the downregulation of Camk2a expression and the deterioration of neurological function. SIGNIFICANCE Treadmill training enhances synaptic plasticity and dendritic remodeling in the ischemic penumbra by inducing the expression of Camk2a via upregulation of CYFIP1.
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Affiliation(s)
- Weimin Shen
- Physical Medicine and Rehabilitation Center, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, No. 109, Xueyuanxi Road, Wenzhou, Zhejiang, China
| | - Lingqin Jin
- Physical Medicine and Rehabilitation Center, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, No. 109, Xueyuanxi Road, Wenzhou, Zhejiang, China
| | - Anqi Zhu
- Physical Medicine and Rehabilitation Center, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, No. 109, Xueyuanxi Road, Wenzhou, Zhejiang, China
| | - Yao Lin
- Physical Medicine and Rehabilitation Center, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, No. 109, Xueyuanxi Road, Wenzhou, Zhejiang, China
| | - Guoyuan Pan
- Physical Medicine and Rehabilitation Center, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, No. 109, Xueyuanxi Road, Wenzhou, Zhejiang, China
| | - Shanshan Zhou
- Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Jingyan Cheng
- The Second Hospital Affiliated to Anhui University of Chinese Medicine, No.300, Shouchun Road, Hefei, Anhui, China
| | - Jieqiong Zhang
- Physical Medicine and Rehabilitation Center, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, No. 109, Xueyuanxi Road, Wenzhou, Zhejiang, China
| | - Fengxia Tu
- Physical Medicine and Rehabilitation Center, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, No. 109, Xueyuanxi Road, Wenzhou, Zhejiang, China
| | - Chan Liu
- Physical Medicine and Rehabilitation Center, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, No. 109, Xueyuanxi Road, Wenzhou, Zhejiang, China
| | - Qingfeng Xie
- Physical Medicine and Rehabilitation Center, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, No. 109, Xueyuanxi Road, Wenzhou, Zhejiang, China.
| | - Xiang Chen
- Physical Medicine and Rehabilitation Center, The Second Affiliated Hospital and Yuying Children's Hospital of Wenzhou Medical University, No. 109, Xueyuanxi Road, Wenzhou, Zhejiang, China.
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22
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Madrid A, Borth LE, Hogan KJ, Hariharan N, Papale LA, Alisch RS, Iskandar BJ. DNA methylation and hydroxymethylation have distinct genome-wide profiles related to axonal regeneration. Epigenetics 2021; 16:64-78. [PMID: 32633672 PMCID: PMC7889172 DOI: 10.1080/15592294.2020.1786320] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/04/2020] [Accepted: 05/28/2020] [Indexed: 12/23/2022] Open
Abstract
Alterations in environmentally sensitive epigenetic mechanisms (e.g., DNA methylation) influence axonal regeneration in the spinal cord following sharp injury. Conventional DNA methylation detection methods using sodium bisulphite treatment do not distinguish between methylated and hydroxymethylated forms of cytosine, meaning that past studies report a composite of 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC). To identify the distinct contributions of DNA methylation modifications to axonal regeneration, we collected spinal cord tissue after sharp injury from untreated adult F3 male rats with enhanced regeneration of injured spinal axons or controls, derived from folate- or water-treated F0 lineages, respectively. Genomic DNA was profiled for genome-wide 5hmC levels, revealing 658 differentially hydroxymethylated regions (DhMRs). Genomic profiling with whole genome bisulphite sequencing disclosed regeneration-related alterations in composite 5mC + 5hmC DNA methylation levels at 2,260 differentially methylated regions (DMRs). While pathway analyses revealed that differentially hydroxymethylated and methylated genes are linked to biologically relevant axon developmental pathways, only 22 genes harbour both DhMR and DMRs. Since these differential modifications were more than 60 kilobases on average away from each other, the large majority of differential hydroxymethylated and methylated regions are unique with distinct functions in the axonal regeneration phenotype. These data highlight the importance of distinguishing independent contributions of 5mC and 5hmC levels in the central nervous system, and denote discrete roles for DNA methylation modifications in spinal cord injury and regeneration in the context of transgenerational inheritance.
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Affiliation(s)
- Andy Madrid
- Department of Neurological Surgery, University of Wisconsin – Madison, Madison, WI, USA
- Neuroscience Training Program, University of Wisconsin – Madison, Madison, WI, USA
| | - Laura E. Borth
- Department of Neurological Surgery, University of Wisconsin – Madison, Madison, WI, USA
- Interdepartmental Graduate Program in Nutritional Science, University of Wisconsin – Madison, Madison, WI, USA
| | - Kirk J. Hogan
- Department of Anesthesiology, University of Wisconsin – Madison, Madison, WI, USA
| | - Nithya Hariharan
- Department of Neurological Surgery, University of Wisconsin – Madison, Madison, WI, USA
| | - Ligia A. Papale
- Department of Neurological Surgery, University of Wisconsin – Madison, Madison, WI, USA
| | - Reid S. Alisch
- Department of Neurological Surgery, University of Wisconsin – Madison, Madison, WI, USA
| | - Bermans J. Iskandar
- Department of Neurological Surgery, University of Wisconsin – Madison, Madison, WI, USA
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23
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Yue C, Shan Z, Tan Y, Yao C, Liu Y, Liu Q, Tan X, Du X. His-Rich Domain of Selenoprotein P Ameliorates Neuropathology and Cognitive Deficits by Regulating TrkB Pathway and Zinc Homeostasis in an Alzheimer Model of Mice. ACS Chem Neurosci 2020; 11:4098-4110. [PMID: 33226214 DOI: 10.1021/acschemneuro.0c00278] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Selenoproteins are a family of special proteins that contain the 21st amino acid, selenocysteine (Sec), in their sequence. Selenoprotein P has 10 Sec residues and modulates selenium homeostasis and redox balance in the brain. Previously, we found that the Sec-devoid His-rich motif of selenoprotein P (Selenop-H) suppressed metal-induced aggregation and neurotoxicities of both Aβ and tau in vitro. To investigate the intervening capacity of Selenop-H on the neuropathology and cognitive deficits of triple transgenic AD (3 × Tg-AD) mice, the Selenop-H gene packaged in rAAV9 was delivered into the hippocampal CA3 regions of mice via stereotaxic injection. Four months later, we demonstrated that Selenop-H (1) improved the spatial learning and memory deficits, (2) alleviated neuron damage and synaptic protein loss, (3) inhibited both tau pathology and amyloid beta protein (Aβ) aggregation, (4) activated both BDNF- and Src-mediated TrkB signaling, and (5) increased MT3 and ZnT3 levels and restored Zn2+ homeostasis in the mice model of AD. The study revealed that Selenop-H is potent in ameliorating AD-related neuropathology and cognitive deficits by modulating TrkB signaling and Zn2+ homeostasis.
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Affiliation(s)
- Caiping Yue
- College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory for Plant Epigenetics, Shenzhen University, Shenzhen 518060, China
| | - Zhifu Shan
- College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory for Plant Epigenetics, Shenzhen University, Shenzhen 518060, China
- College of Veterinary Medicine, Northeast Agricultural University, No. 600 Chang jiang Street, Harbin 150030, P. R. China
| | - Yibin Tan
- College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory for Plant Epigenetics, Shenzhen University, Shenzhen 518060, China
| | - Chuangyu Yao
- College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory for Plant Epigenetics, Shenzhen University, Shenzhen 518060, China
| | - Yuanheng Liu
- Advance Institute of Engineering Science for Intelligent Manufacturing, Guangzhou University, Guangzhou, Guangdong 510006, China
| | - Qiong Liu
- College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory for Plant Epigenetics, Shenzhen University, Shenzhen 518060, China
- Shenzhen Bay Laboratory, Shenzhen 518055, China
| | - Xiangshi Tan
- Department of Chemistry &Shanghai Key Laboratory of Chemical Biology for Protein Research and Institutes of Biomedical Sciences, Fudan University, Shanghai 200433, China
| | - Xiubo Du
- College of Life Sciences and Oceanography, Guangdong Provincial Key Laboratory for Plant Epigenetics, Shenzhen University, Shenzhen 518060, China
- Shenzhen Bay Laboratory, Shenzhen 518055, China
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24
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Abstract
Derivation of induced Pluripotent Stem Cells (iPSCs) by reprogramming somatic cells to a pluripotent state has revolutionized stem cell research. Ensuing this, various groups have used genetic and non-genetic approaches to generate iPSCs from numerous cell types. However, achieving a pluripotent state in most of the reprogramming studies is marred by serious limitations such as low reprogramming efficiency and slow kinetics. These limitations are mainly due to the presence of potent barriers that exist during reprogramming when a mature cell is coaxed to achieve a pluripotent state. Several studies have revealed that intrinsic factors such as non-optimal stoichiometry of reprogramming factors, specific signaling pathways, cellular senescence, pluripotency-inhibiting transcription factors and microRNAs act as a roadblock. In addition, the epigenetic state of somatic cells and specific epigenetic modifications that occur during reprogramming also remarkably impede the generation of iPSCs. In this review, we present a comprehensive overview of the barriers that inhibit reprogramming and the understanding of which will pave the way to develop safe strategies for efficient reprogramming.
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25
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Presynaptic L-Type Ca 2+ Channels Increase Glutamate Release Probability and Excitatory Strength in the Hippocampus during Chronic Neuroinflammation. J Neurosci 2020; 40:6825-6841. [PMID: 32747440 DOI: 10.1523/jneurosci.2981-19.2020] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 06/18/2020] [Accepted: 07/20/2020] [Indexed: 12/21/2022] Open
Abstract
Neuroinflammation is involved in the pathogenesis of several neurologic disorders, including epilepsy. Both changes in the input/output functions of synaptic circuits and cell Ca2+ dysregulation participate in neuroinflammation, but their impact on neuron function in epilepsy is still poorly understood. Lipopolysaccharide (LPS), a toxic byproduct of bacterial lysis, has been extensively used to stimulate inflammatory responses both in vivo and in vitro LPS stimulates Toll-like receptor 4, an important mediator of the brain innate immune response that contributes to neuroinflammation processes. Although we report that Toll-like receptor 4 is expressed in both excitatory and inhibitory mouse hippocampal neurons (both sexes), its chronic stimulation by LPS induces a selective increase in the excitatory synaptic strength, characterized by enhanced synchronous and asynchronous glutamate release mechanisms. This effect is accompanied by a change in short-term plasticity with decreased facilitation, decreased post-tetanic potentiation, and increased depression. Quantal analysis demonstrated that the effects of LPS on excitatory transmission are attributable to an increase in the probability of release associated with an overall increased expression of L-type voltage-gated Ca2+ channels that, at presynaptic terminals, abnormally contributes to evoked glutamate release. Overall, these changes contribute to the excitatory/inhibitory imbalance that scales up neuronal network activity under inflammatory conditions. These results provide new molecular clues for treating hyperexcitability of hippocampal circuits associated with neuroinflammation in epilepsy and other neurologic disorders.SIGNIFICANCE STATEMENT Neuroinflammation is thought to have a pathogenetic role in epilepsy, a disorder characterized by an imbalance between excitation/inhibition. Fine adjustment of network excitability and regulation of synaptic strength are both implicated in the homeostatic maintenance of physiological levels of neuronal activity. Here, we focused on the effects of chronic neuroinflammation induced by lipopolysaccharides on hippocampal glutamatergic and GABAergic synaptic transmission. Our results show that, on chronic stimulation with lipopolysaccharides, glutamatergic, but not GABAergic, neurons exhibit an enhanced synaptic strength and changes in short-term plasticity because of an increased glutamate release that results from an anomalous contribution of L-type Ca2+ channels to neurotransmitter release.
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26
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Bonnycastle K, Davenport EC, Cousin MA. Presynaptic dysfunction in neurodevelopmental disorders: Insights from the synaptic vesicle life cycle. J Neurochem 2020; 157:179-207. [PMID: 32378740 DOI: 10.1111/jnc.15035] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/14/2020] [Accepted: 04/22/2020] [Indexed: 12/11/2022]
Abstract
The activity-dependent fusion, retrieval and recycling of synaptic vesicles is essential for the maintenance of neurotransmission. Until relatively recently it was believed that most mutations in genes that were essential for this process would be incompatible with life, because of this fundamental role. However, an ever-expanding number of mutations in this very cohort of genes are being identified in individuals with neurodevelopmental disorders, including autism, intellectual disability and epilepsy. This article will summarize the current state of knowledge linking mutations in presynaptic genes to neurodevelopmental disorders by sequentially covering the various stages of the synaptic vesicle life cycle. It will also discuss how perturbations of specific stages within this recycling process could translate into human disease. Finally, it will also provide perspectives on the potential for future therapy that are targeted to presynaptic function.
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Affiliation(s)
- Katherine Bonnycastle
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Elizabeth C Davenport
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.,Muir Maxwell Epilepsy Centre, University of Edinburgh, Edinburgh, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh, UK
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27
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Choi DJ, Yang H, Gaire S, Lee KA, An J, Kim BG, Jou I, Park SM, Joe EH. Critical roles of astrocytic-CCL2-dependent monocyte infiltration in a DJ-1 knockout mouse model of delayed brain repair. Glia 2020; 68:2086-2101. [PMID: 32176388 DOI: 10.1002/glia.23828] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 01/25/2020] [Accepted: 02/27/2020] [Indexed: 01/01/2023]
Abstract
Monocyte-derived macrophages play a role in the repair of the injured brain. We previously reported that a deficiency of the Parkinson's disease (PD)-associated gene DJ-1 delays repair of brain injury produced by stereotaxic injection of ATP, a component of damage-associated molecular patterns. Here, we show that a DJ-1 deficiency attenuates monocyte infiltration into the damaged brain owing to a decrease in C-C motif chemokine ligand 2 (CCL2) expression in astrocytes. Like DJ-1-knockout (KO) mice, CCL2 receptor (CCR2)-KO mice showed defects in monocyte infiltration and delayed recovery of brain injury, as determined by 9.4 T magnetic resonance imaging analysis and immunostaining for tyrosine hydroxylase and glial fibrillary acid protein. Notably, transcriptome analyses showed that genes related to regeneration and synapse formation were similarly downregulated in injured brains of DJ-1-KO and CCR2-KO mice compared with the injured wild-type brain. These results indicate that defective astrogliosis in DJ-1-KO mice is associated with decreased CCL2 expression and attenuated monocyte infiltration, resulting in delayed repair of brain injury. Thus, delayed repair of brain injury could contribute to the development of PD. MAIN POINTS: A DJ-1 deficiency attenuates infiltration of monocytes owing to a decrease in CCL2 expression in astrocytes, which in turn led to delay in repair of brain injury.
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Affiliation(s)
- Dong-Joo Choi
- Department of Pharmacology, National Research Lab of Brain Inflammation, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea
| | - Hajie Yang
- Department of Pharmacology, National Research Lab of Brain Inflammation, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Department of Brain Science, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea
| | - Sushil Gaire
- Department of Pharmacology, National Research Lab of Brain Inflammation, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Department of Brain Science, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea
| | - Keon Ah Lee
- Department of Pharmacology, National Research Lab of Brain Inflammation, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Department of Brain Science, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea
| | - Jiawei An
- Department of Pharmacology, National Research Lab of Brain Inflammation, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Department of Brain Science, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea
| | - Byung Gon Kim
- Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Department of Brain Science, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Department of Neurology, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea
| | - Ilo Jou
- Department of Pharmacology, National Research Lab of Brain Inflammation, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea
| | - Sang Myun Park
- Department of Pharmacology, National Research Lab of Brain Inflammation, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea
| | - Eun-Hye Joe
- Department of Pharmacology, National Research Lab of Brain Inflammation, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Chronic Inflammatory Disease Research Center, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Department of Brain Science, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea.,Neuroscience Graduate Program, Department of Biomedical Sciences, Ajou University School of Medicine, Suwon, Kyunggi-do, South Korea
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28
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Forte N, Binda F, Contestabile A, Benfenati F, Baldelli P. Synapsin I Synchronizes GABA Release in Distinct Interneuron Subpopulations. Cereb Cortex 2019; 30:1393-1406. [DOI: 10.1093/cercor/bhz174] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 07/02/2019] [Accepted: 07/03/2019] [Indexed: 01/28/2023] Open
Abstract
Abstract
Neurotransmitters can be released either synchronously or asynchronously with respect to action potential timing. Synapsins (Syns) are a family of synaptic vesicle (SV) phosphoproteins that assist gamma-aminobutyric acid (GABA) release and allow a physiological excitation/inhibition balance. Consistently, deletion of either or both Syn1 and Syn2 genes is epileptogenic. In this work, we have characterized the effect of SynI knockout (KO) in the regulation of GABA release dynamics. Using patch-clamp recordings in hippocampal slices, we demonstrate that the lack of SynI impairs synchronous GABA release via a reduction of the readily releasable SVs and, in parallel, increases asynchronous GABA release. The effects of SynI deletion on synchronous GABA release were occluded by ω-AgatoxinIVA, indicating the involvement of P/Q-type Ca2+channel-expressing neurons. Using in situ hybridization, we show that SynI is more expressed in parvalbumin (PV) interneurons, characterized by synchronous release, than in cholecystokinin or SOM interneurons, characterized by a more asynchronous release. Optogenetic activation of PV and SOM interneurons revealed a specific reduction of synchronous release in PV/SynIKO interneurons associated with an increased asynchronous release in SOM/SynIKO interneurons. The results demonstrate that SynI is differentially expressed in interneuron subpopulations, where it boosts synchronous and limits asynchronous GABA release.
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Affiliation(s)
- N Forte
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
- IRCSS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - F Binda
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
- IRCSS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - A Contestabile
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Via Morego 30, 16163 Genova, Italy
| | - F Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
- IRCSS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - P Baldelli
- IRCSS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
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29
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Lugarà E, De Fusco A, Lignani G, Benfenati F, Humeau Y. Synapsin I Controls Synaptic Maturation of Long-Range Projections in the Lateral Amygdala in a Targeted Selective Fashion. Front Cell Neurosci 2019; 13:220. [PMID: 31164805 PMCID: PMC6536628 DOI: 10.3389/fncel.2019.00220] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2018] [Accepted: 05/01/2019] [Indexed: 01/11/2023] Open
Abstract
The amygdala, and more precisely its lateral nucleus, is thought to attribute emotional valence to external stimuli by generating long-term plasticity changes at long-range projections to principal cells. Aversive experience has also been shown to modify pre- and post-synaptic markers in the amygdala, suggesting their possible role in the structural organization of adult amygdala networks. Here, we focused on how the maturation of cortical and thalamic long-range projections occurs on principal neurons and interneurons in the lateral amygdala (LA). We performed dual electrophysiological recordings of identified cells in juvenile and adult GAD67-GFP mice after independent stimulation of cortical and thalamic afferent systems. The results demonstrate that synaptic strengthening occurs during development at synapses projecting to LA principal neurons, but not interneurons. As synaptic strengthening underlies fear conditioning which depends, in turn, on presence and increasing expression of synapsin I, we tested if synapsin I contributes to synaptic strengthening during development. Interestingly, the physiological synaptic strengthening of cortical and thalamic synapses projecting to LA principal neurons was virtually abolished in synapsin I knockout mice, but not differences were observed in the excitatory projections to interneurons. Immunohistochemistry analysis showed that the presence of synapsin I is restricted to excitatory contacts projecting to principal neurons in LA of adult mice. These results indicate that synapsin I is a key regulator of the maturation of synaptic connectivity in this brain region and that is expression is dependent on postsynaptic identity.
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Affiliation(s)
- Eleonora Lugarà
- Department of Experimental Medicine, Section of Human Physiology, University of Genova, Genoa, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Antonio De Fusco
- Department of Experimental Medicine, Section of Human Physiology, University of Genova, Genoa, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Gabriele Lignani
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Yann Humeau
- Team Synapse in Cognition, Institut Interdisciplinaire de Neuroscience, Centre National de la Recherche Scientifique CNRS UMR5297, Université de Bordeaux, Bordeaux, France
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Dorgans K, Demais V, Bailly Y, Poulain B, Isope P, Doussau F. Short-term plasticity at cerebellar granule cell to molecular layer interneuron synapses expands information processing. eLife 2019; 8:41586. [PMID: 31081751 PMCID: PMC6533085 DOI: 10.7554/elife.41586] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2018] [Accepted: 05/11/2019] [Indexed: 12/14/2022] Open
Abstract
Information processing by cerebellar molecular layer interneurons (MLIs) plays a crucial role in motor behavior. MLI recruitment is tightly controlled by the profile of short-term plasticity (STP) at granule cell (GC)-MLI synapses. While GCs are the most numerous neurons in the brain, STP diversity at GC-MLI synapses is poorly documented. Here, we studied how single MLIs are recruited by their distinct GC inputs during burst firing. Using slice recordings at individual GC-MLI synapses of mice, we revealed four classes of connections segregated by their STP profile. Each class differentially drives MLI recruitment. We show that GC synaptic diversity is underlain by heterogeneous expression of synapsin II, a key actor of STP and that GC terminals devoid of synapsin II are associated with slow MLI recruitment. Our study reveals that molecular, structural and functional diversity across GC terminals provides a mechanism to expand the coding range of MLIs.
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Affiliation(s)
- Kevin Dorgans
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, Université de Strasbourg, Strasbourg, France
| | - Valérie Demais
- Plateforme Imagerie in vitro, CNRS UPS 3156, Strasbourg, France
| | - Yannick Bailly
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, Université de Strasbourg, Strasbourg, France.,Plateforme Imagerie in vitro, CNRS UPS 3156, Strasbourg, France
| | - Bernard Poulain
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, Université de Strasbourg, Strasbourg, France
| | - Philippe Isope
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, Université de Strasbourg, Strasbourg, France
| | - Frédéric Doussau
- Institut des Neurosciences Cellulaires et Intégratives, CNRS UPR 3212, Université de Strasbourg, Strasbourg, France
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Ustyantsev KV, Goncharov NP. Homology of Genes Controlling Architectonics of Vegetative and Generative Organs in Barley and Rice and Their Application for Wheat Biodiversity Expansion and Breeding. RUSS J GENET+ 2019. [DOI: 10.1134/s1022795419050156] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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32
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Matos H, Quiles R, Andrade R, Bykhovskaia M. Growth and excitability at synapsin II deficient hippocampal neurons. Mol Cell Neurosci 2019; 96:25-34. [PMID: 30858140 DOI: 10.1016/j.mcn.2019.03.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 02/25/2019] [Accepted: 03/07/2019] [Indexed: 10/27/2022] Open
Abstract
Synapsins are neuronal phosphoproteins that fine-tune synaptic transmission and suppress seizure activity. Synapsin II (SynII) deletion produces epileptic seizures and overexcitability in neuronal networks. Early studies in primary neuronal cultures have shown that SynII deletion results in a delay in synapse formation. More recent studies at hippocampal slices have revealed increased spontaneous activity in SynII knockout (SynII(-)) mice. To reconcile these observations, we systematically re-examined synaptic transmission, synapse formation, and neurite growth in primary hippocampal neuronal cultures. We find that spontaneous glutamatergic synaptic activity was suppressed in SynII(-) neurons during the initial developmental epoch (7 days in vitro, DIV) but was enhanced at later times (12 and18 DIV). The density of synapses, transmission between connected pairs of neurons, and the number of docked synaptic vesicles were not affected by SynII deletion. However, we found that neurite outgrowth in SynII(-) neurons was suppressed during the initial developmental epoch (7 DIV) but enhanced at subsequent developmental stages (12 and18 DIV). This finding can account for the observed effect of SynII deletion on synaptic activity. To test whether the observed phenotype resulted directly from the deletion of SynII we expressed SynII in SynII(-) cultures using an adeno-associated virus (AAV). Expression of SynII at 2 DIV rescued the SynII deletion-dependent alterations in both synaptic activity and neuronal growth. To test whether the increased neurite outgrowth in SynII(-) observed at DIV 12 and18 represents an overcompensation for the initial developmental delay or results directly from SynII deletion we performed "late expression" experiments, transfecting SynII(-) cultures with AAV at 7 DIV. The late SynII expression suppressed neurite outgrowth at 12 and 18 DIV to the levels observed in control neurons, suggesting that these phenotypes directly depend on SynII. These results reveal a novel developmentally regulated role for SynII function in the control of neurite growth.
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Affiliation(s)
- Heidi Matos
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Raymond Quiles
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Rodrigo Andrade
- Department of Pharmacology, Wayne State University School of Medicine, Detroit, MI, United States of America
| | - Maria Bykhovskaia
- Department of Neurology, Wayne State University School of Medicine, Detroit, MI, United States of America.
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Decreased dopamine in striatum and difficult locomotor recovery from MPTP insult after exposure to radiofrequency electromagnetic fields. Sci Rep 2019; 9:1201. [PMID: 30718744 PMCID: PMC6362053 DOI: 10.1038/s41598-018-37874-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Accepted: 12/12/2018] [Indexed: 12/23/2022] Open
Abstract
Concern is growing about possible neuronal effects of human exposure to radiofrequency electromagnetic fields because of the increasing usage of cell phones and the close proximity of these devices to the brain when in use. We found that exposure to a radiofrequency electromagnetic field (RF-EMF) of 835 MHz (4.0 W/kg specific absorption rate [SAR] for 5 h/day for 12 weeks) affects striatal neurons in C57BL/6 mice. The number of synaptic vesicles (SVs) in striatal presynaptic boutons was significantly decreased after RF-EMF exposure. The expression levels of synapsin I and II were also significantly decreased in the striatum of the RF-EMF-exposed group. RF-EMF exposure led to a reduction in dopamine concentration in the striatum and also to a decrease in the expression of tyrosine hydroxylase in striatal neurons. Furthermore, in behavioral tests, exposure to RF-EMF impeded the recovery of locomotor activities after repeated treatments with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). These results suggest that the observed decrease in dopamine concentration in the striatum was caused by both a reduction in the number of dopaminergic neurons and a decline in the number of SVs. The decreased dopamine neuron numbers and concentration seen after RF-EMF exposure would have caused the difficult recovery after MPTP treatment. In summary, our results strongly suggest that exposing the brain to RF-EMF can decrease the number of SVs and dopaminergic neurons in the striatum. These primary changes impair the recovery of locomotor activities following MPTP damage to the striatum.
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Thomson S, Dyck B, Daya R, Ho J, Bernardo A, Tian Y, Mishra RK. Reduced expression of synapsin II in a chronic phencyclidine preclinical rat model of schizophrenia. Synapse 2018; 73:e22084. [PMID: 30582667 DOI: 10.1002/syn.22084] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2018] [Revised: 12/11/2018] [Accepted: 12/16/2018] [Indexed: 12/25/2022]
Abstract
Schizophrenia is a mental disorder characterized by positive symptoms, negative symptoms, and cognitive dysfunction. Phencyclidine (PCP)-a N-methyl-D-aspartate (NMDA) receptor antagonist-induces symptoms indistinguishable from those of schizophrenia. A reduction of the phosphoprotein synapsin II has also been implicated in schizophrenia and has a well-known role in the maintenance of the presynaptic reserve pool and vesicle mobilization. This study assessed the behavioral and biochemical outcomes of chronic NMDA receptor antagonism in rodents and its implications for the pathophysiology of schizophrenia. Sprague Dawley rats received saline or chronic PCP (5 mg/kg/day) for 14 days via surgically implanted Alzet® osmotic mini-pumps. Following the treatment period, rats were tested with a series of behavioral paradigms, including locomotor activity, social interaction, and sensorimotor gating. Following behavioral assessment, the medial prefrontal cortex (mPFC) of all rats was isolated for synapsin II protein analysis. Chronic PCP treatment yielded a hyper-locomotive state (p = 0.0256), reduced social interaction (p = 0.0005), and reduced pre-pulse inhibition (p < 0.0001) in comparison to saline-treated controls. Synapsin IIa (p < 0.0001) and IIb (p < 0.0071) levels in the mPFC of chronically treated PCP rats were reduced in comparison to the saline group. Study results confirm that rats subject to chronic PCP treatment display behavioral phenotypes similar to established preclinical animal models of schizophrenia. Reduction of synapsin II expression in this context implicates the role of this protein in the pathophysiology of schizophrenia and sheds light on the longer-term consequences of NMDA receptor antagonism facilitated by chronic PCP treatment.
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Affiliation(s)
- Sharon Thomson
- Faculty of Health Sciences, Department of Psychiatry and Behavioral Neuroscience, McMaster University, Hamilton, Ontario, Canada
| | - Bailey Dyck
- Faculty of Health Sciences, Department of Psychiatry and Behavioral Neuroscience, McMaster University, Hamilton, Ontario, Canada
| | - Ritesh Daya
- Faculty of Health Sciences, Department of Psychiatry and Behavioral Neuroscience, McMaster University, Hamilton, Ontario, Canada
| | - Joella Ho
- Faculty of Health Sciences, Department of Psychiatry and Behavioral Neuroscience, McMaster University, Hamilton, Ontario, Canada
| | - Ashley Bernardo
- Faculty of Health Sciences, Department of Psychiatry and Behavioral Neuroscience, McMaster University, Hamilton, Ontario, Canada
| | - Yuxin Tian
- Faculty of Health Sciences, Department of Psychiatry and Behavioral Neuroscience, McMaster University, Hamilton, Ontario, Canada
| | - Ram K Mishra
- Faculty of Health Sciences, Department of Psychiatry and Behavioral Neuroscience, McMaster University, Hamilton, Ontario, Canada
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35
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Jike W, Sablok G, Bertorelle G, Li M, Varotto C. In silico identification and characterization of a diverse subset of conserved microRNAs in bioenergy crop Arundo donax L. Sci Rep 2018; 8:16667. [PMID: 30420632 PMCID: PMC6232160 DOI: 10.1038/s41598-018-34982-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 10/15/2018] [Indexed: 01/08/2023] Open
Abstract
MicroRNAs (miRNAs) are small non-coding RNA molecules involved in the post-transcriptional regulation of gene expression in plants. Arundo donax L. is a perennial C3 grass considered one of the most promising bioenergy crops. Despite its relevance, many fundamental aspects of its biology still remain to be elucidated. In the present study we carried out the first in silico mining and tissue-specific characterization of microRNAs and their putative targets in A. donax. We identified a total of 141 miRNAs belonging to 14 families along with the corresponding primary miRNAs, precursor miRNAs and a total of 462 high-confidence predicted targets and novel target sites were validated by 5′-race. Gene Ontology functional annotation showed that miRNA targets are constituted mainly by transcription factors, but three of the newly validated targets are enzymes involved in novel functions like RNA editing, acyl lipid metabolism and post-Golgi trafficking. Folding variability of pre-miRNA loops and phylogenetic analyses indicate variable selective pressure acting on the different miRNA families. The set of miRNAs identified in this study will pave the road to further miRNA research in Arundo donax and contribute towards a better understanding of miRNA-mediated gene regulatory processes in other bioenergy crops.
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Affiliation(s)
- Wuhe Jike
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.,Università degli Studi di Ferrara, Dipartimento di Scienze della Vita e Biotecnologie, Ferrara, Italy
| | - Gaurav Sablok
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.,Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Giorgio Bertorelle
- Università degli Studi di Ferrara, Dipartimento di Scienze della Vita e Biotecnologie, Ferrara, Italy
| | - Mingai Li
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.
| | - Claudio Varotto
- Department of Biodiversity and Molecular Ecology, Research and Innovation Centre, Fondazione Edmund Mach, San Michele all'Adige, Trento, Italy.
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36
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Cheng Q, Song SH, Augustine GJ. Molecular Mechanisms of Short-Term Plasticity: Role of Synapsin Phosphorylation in Augmentation and Potentiation of Spontaneous Glutamate Release. Front Synaptic Neurosci 2018; 10:33. [PMID: 30425632 PMCID: PMC6218601 DOI: 10.3389/fnsyn.2018.00033] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2018] [Accepted: 09/20/2018] [Indexed: 12/24/2022] Open
Abstract
We used genetic and pharmacological approaches to identify the signaling pathways involved in augmentation and potentiation, two forms of activity dependent, short-term synaptic plasticity that enhance neurotransmitter release. Trains of presynaptic action potentials produced a robust increase in the frequency of miniature excitatory postsynaptic currents (mEPSCs). Following the end of the stimulus, mEPSC frequency followed a bi-exponential decay back to basal levels. The time constants of decay identified these two exponential components as the decay of augmentation and potentiation, respectively. Augmentation increased mEPSC frequency by 9.3-fold, while potentiation increased mEPSC frequency by 2.4-fold. In synapsin triple-knockout (TKO) neurons, augmentation was reduced by 83% and potentiation was reduced by 74%, suggesting that synapsins are key signaling elements in both forms of plasticity. To examine the synapsin isoforms involved, we expressed individual synapsin isoforms in TKO neurons. While synapsin IIIa rescued both augmentation and potentiation, none of the other synapsin isoforms produced statistically significant amounts of rescue. To determine the involvement of protein kinases in these two forms of short-term plasticity, we examined the effects of inhibitors of protein kinases A (PKA) and C (PKC). While inhibition of PKC had little effect, PKA inhibition reduced augmentation by 76% and potentiation by 60%. Further, elevation of intracellular cAMP concentration, by either forskolin or IBMX, greatly increased mEPSC frequency and occluded the amount of augmentation and potentiation evoked by electrical stimulation. Finally, mutating a PKA phosphorylation site to non-phosphorylatable alanine largely abolished the ability of synapsin IIIa to rescue both augmentation and potentiation. Together, these results indicate that PKA activation is required for both augmentation and potentiation of spontaneous neurotransmitter release and that PKA-mediated phosphorylation of synapsin IIIa underlies both forms of presynaptic short-term plasticity.
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Affiliation(s)
- Qing Cheng
- Laboratory of Neurobiology, National Institute of Environmental Health Sciences, National Institutes of Health, Durham, NC, United States
| | - Sang-Ho Song
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - George J Augustine
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore.,Institute of Molecular and Cell Biology, Singapore, Singapore
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Michetti C, Caruso A, Pagani M, Sabbioni M, Medrihan L, David G, Galbusera A, Morini M, Gozzi A, Benfenati F, Scattoni ML. The Knockout of Synapsin II in Mice Impairs Social Behavior and Functional Connectivity Generating an ASD-like Phenotype. Cereb Cortex 2018; 27:5014-5023. [PMID: 28922833 DOI: 10.1093/cercor/bhx207] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2017] [Indexed: 12/28/2022] Open
Abstract
Autism spectrum disorders (ASD) and epilepsy are neurodevelopmental conditions that appear with high rate of co-occurrence, suggesting the possibility of a common genetic basis. Mutations in Synapsin (SYN) genes, particularly SYN1 and SYN2, have been recently associated with ASD and epilepsy in humans. Accordingly, mice lacking Syn1 or Syn2, but not Syn3, experience epileptic seizures and display autistic-like traits that precede the onset of seizures. Here, we analyzed social behavior and ultrasonic vocalizations emitted in 2 social contexts by SynI, SynII, or SynIII mutants and show that SynII mutants display the most severe ASD-like phenotype. We also show that the behavioral SynII phenotype correlates with a significant decrease in auditory and hippocampal functional connectivity as measured with resting state functional magnetic resonance imaging (rsfMRI). Taken together, our results reveal a permissive contribution of Syn2 to the expression of normal socio-communicative behavior, and suggest that Syn2-mediated synaptic dysfunction can lead to ASD-like behavior through dysregulation of cortical connectivity.
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Affiliation(s)
- Caterina Michetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova 16132, Italy
| | - Angela Caruso
- Research Coordination and support Service, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Marco Pagani
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, Istituto Italiano di Tecnologia, Rovereto 38068, Italy.,Center for Mind and Brain Sciences, University of Trento, Rovereto 38068, Italy
| | - Mara Sabbioni
- Research Coordination and support Service, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
| | - Lucian Medrihan
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova 16132, Italy
| | - Gergely David
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, Istituto Italiano di Tecnologia, Rovereto 38068, Italy
| | - Alberto Galbusera
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, Istituto Italiano di Tecnologia, Rovereto 38068, Italy
| | - Monica Morini
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova 16132, Italy
| | - Alessandro Gozzi
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems @ UniTn, Istituto Italiano di Tecnologia, Rovereto 38068, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova 16132, Italy
| | - Maria Luisa Scattoni
- Research Coordination and support Service, Istituto Superiore di Sanità, Viale Regina Elena 299, 00161 Rome, Italy
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Valente P, Romei A, Fadda M, Sterlini B, Lonardoni D, Forte N, Fruscione F, Castroflorio E, Michetti C, Giansante G, Valtorta F, Tsai JW, Zara F, Nieus T, Corradi A, Fassio A, Baldelli P, Benfenati F. Constitutive Inactivation of the PRRT2 Gene Alters Short-Term Synaptic Plasticity and Promotes Network Hyperexcitability in Hippocampal Neurons. Cereb Cortex 2018; 29:2010-2033. [DOI: 10.1093/cercor/bhy079] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Revised: 03/13/2018] [Indexed: 12/20/2022] Open
Affiliation(s)
- Pierluigi Valente
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV 3, Genova, Italy
| | - Alessandra Romei
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV 3, Genova, Italy
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova, Italy
| | - Manuela Fadda
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV 3, Genova, Italy
| | - Bruno Sterlini
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV 3, Genova, Italy
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova, Italy
| | - Davide Lonardoni
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Via Morego 30, Genova, Italy
| | - Nicola Forte
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova, Italy
| | - Floriana Fruscione
- Laboratory of Neurogenetics and Neuroscience, Department Head-Neck and Neuroscience, Istituto Giannina Gaslini, Via Gerolamo Gaslini 5, Genova, Italy
| | - Enrico Castroflorio
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV 3, Genova, Italy
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova, Italy
| | - Caterina Michetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova, Italy
| | - Giorgia Giansante
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV 3, Genova, Italy
| | - Flavia Valtorta
- San Raffaele Scientific Institute and Vita Salute University, Via Olgettina 58, Milano, Italy
| | - Jin-Wu Tsai
- Institute of Brain Science, Brain Research Center, National Yang-Ming University, Taipei, Taiwan
| | - Federico Zara
- Laboratory of Neurogenetics and Neuroscience, Department Head-Neck and Neuroscience, Istituto Giannina Gaslini, Via Gerolamo Gaslini 5, Genova, Italy
| | - Thierry Nieus
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Via Morego 30, Genova, Italy
| | - Anna Corradi
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV 3, Genova, Italy
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova, Italy
| | - Anna Fassio
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV 3, Genova, Italy
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV 3, Genova, Italy
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova, Italy
| | - Fabio Benfenati
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV 3, Genova, Italy
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, Genova, Italy
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39
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Barbieri R, Contestabile A, Ciardo MG, Forte N, Marte A, Baldelli P, Benfenati F, Onofri F. Synapsin I and Synapsin II regulate neurogenesis in the dentate gyrus of adult mice. Oncotarget 2018; 9:18760-18774. [PMID: 29721159 PMCID: PMC5922353 DOI: 10.18632/oncotarget.24655] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2017] [Accepted: 02/25/2018] [Indexed: 01/23/2023] Open
Abstract
Adult neurogenesis is emerging as an important player in brain functions and homeostasis, while impaired or altered adult neurogenesis has been associated with a number of neuropsychiatric diseases, such as depression and epilepsy. Here we investigated the possibility that synapsins (Syns) I and II, beyond their known functions in developing and mature neurons, also play a role in adult neurogenesis. We performed a systematic evaluation of the distinct stages of neurogenesis in the hippocampal dentate gyrus of Syn I and Syn II knockout (KO) mice, before (2-months-old) and after (6-months-old) the appearance of the epileptic phenotype. We found that Syns I and II play an important role in the regulation of adult neurogenesis. In juvenile mice, Syn II deletion was associated with a specific decrease in the proliferation of neuronal progenitors, whereas Syn I deletion impaired the survival of newborn neurons. These defects were reverted after the appearance of the epileptic phenotype, with Syn I KO and Syn II KO mice exhibiting significant increases in survival and proliferation, respectively. Interestingly, long-term potentiation dependent on newborn neurons was present in both juvenile Syn mutants while, at later ages, it was only preserved in Syn II KO mice that also displayed an increased expression of brain-derived neurotrophic factor. This study suggests that Syns I and II play a role in adult neurogenesis and the defects in neurogenesis associated with Syn deletion may contribute to the alterations of cognitive functions observed in Syn-deficient mice.
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Affiliation(s)
- Raffaella Barbieri
- Department of Experimental Medicine, University of Genova, 16132, Genova, Italy
| | - Andrea Contestabile
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, 16163, Genova, Italy
| | - Maria Grazia Ciardo
- Department of Experimental Medicine, University of Genova, 16132, Genova, Italy
| | - Nicola Forte
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132, Genova, Italy
| | - Antonella Marte
- Department of Experimental Medicine, University of Genova, 16132, Genova, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genova, 16132, Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132, Genova, Italy
| | - Fabio Benfenati
- Department of Experimental Medicine, University of Genova, 16132, Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132, Genova, Italy
| | - Franco Onofri
- Department of Experimental Medicine, University of Genova, 16132, Genova, Italy
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40
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Joshi H, Sharma R, Prashar S, Ho J, Thomson S, Mishra R. Differential Expression of Synapsin I and II upon Treatment by Lithium and Valproic Acid in Various Brain Regions. Int J Neuropsychopharmacol 2018; 21:616-622. [PMID: 29618019 PMCID: PMC6007270 DOI: 10.1093/ijnp/pyy023] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
INTRODUCTION Due to the heterogeneity of psychiatric illnesses and overlapping mechanisms, patients with psychosis are differentially responsive to pharmaceutical drugs. In addition to having therapeutic effects for schizophrenia and bipolar disorder, antipsychotics and mood stabilizers have many clinical applications and are used unconventionally due to their direct and indirect effects on neurotransmitters. Synapsins, a family of neuronal phosphoproteins, play a key regulatory role in neurotransmitter release at synapses. In this study, we investigated the effects of mood stabilizers, lithium, and valproic acid on synapsin gene expression in the rat brain. METHODS Intraperitoneal injections of saline, lithium, and valproic acid were administered to male Sprague Dawley rats twice daily for 14 d, corresponding to their treatment group. Following decapitation and brain tissue isolation, mRNA was extracted from various brain regions including the hippocampus, striatum, prefrontal cortex, and frontal cortex. RESULTS Biochemical analysis revealed that lithium significantly increased gene expression of synapsin I in the striatum, synapsin IIa in the hippocampus and prefrontal cortex, and synapsin IIb in the hippocampus and striatum. Valproic acid significantly increased synapsin IIa in the hippocampus and prefrontal cortex, as well as synapsin IIb in the hippocampus and striatum. CONCLUSION These significant changes in synapsin I and II expression may implicate a common transcription factor, early growth response 1, in its mechanistic pathway. Overall, these results elucidate mechanisms through which lithium and valproic acid act on downstream targets compared with antipsychotics and provide deeper insight on the involvement of synaptic proteins in treating neuropsychiatric illnesses.
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Affiliation(s)
- Hetshree Joshi
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Roohie Sharma
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Shreya Prashar
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Joella Ho
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Sharon Thomson
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada
| | - Ram Mishra
- Department of Psychiatry and Behavioural Neurosciences, McMaster University, Hamilton, Ontario, Canada,Correspondence: Ram K. Mishra, PhD, Department of Psychiatry and Behavioural Neurosciences, McMaster University, 1280 Main St W. Hamilton, ON L8S 4L8 Canada ()
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41
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Simonato M. Epilepsy an Update on Disease Mechanisms: The Potential Role of MicroRNAs. Front Neurol 2018; 9:176. [PMID: 29615968 PMCID: PMC5868323 DOI: 10.3389/fneur.2018.00176] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2017] [Accepted: 03/07/2018] [Indexed: 01/25/2023] Open
Abstract
So far, research on epilepsy mechanisms has been designed mainly using animal models and tracking down molecular mechanisms underlying seizures in that model. While this approach is clearly valuable, it can be questioned if it is the best possible. One attractive alternative approach may stem from the consideration of epilepsy as a complex disease of a very complex organ, the brain. This short review summarizes data from analyses of the alterations in expression of microRNAs and their target messenger RNAs in a specific brain subregion, the dentate gyrus of the hippocampus, in three experimental models of lesional epilepsy. The findings are discussed within the conceptual framework of complex systems.
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Affiliation(s)
- Michele Simonato
- Department of Medical Sciences, University of Ferrara, Ferrara, Italy.,School of Medicine, University Vita-Salute San Raffaele, Milan, Italy
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42
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Guarnieri FC, Bellani S, Yekhlef L, Bergamaschi A, Finardi A, Fesce R, Pozzi D, Monzani E, Fornasiero EF, Matteoli M, Martino G, Furlan R, Taverna S, Muzio L, Valtorta F. Synapsin I deletion reduces neuronal damage and ameliorates clinical progression of experimental autoimmune encephalomyelitis. Brain Behav Immun 2018; 68:197-210. [PMID: 29066310 DOI: 10.1016/j.bbi.2017.10.018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2017] [Revised: 10/10/2017] [Accepted: 10/20/2017] [Indexed: 11/20/2022] Open
Abstract
The classical view of multiple sclerosis (MS) pathogenesis states that inflammation-mediated demyelination is responsible for neuronal damage and loss. However, recent findings show that impairment of neuronal functions and demyelination can be independent events, suggesting the coexistence of other pathogenic mechanisms. Due to the inflammatory milieu, subtle alterations in synaptic function occur, which are probably at the basis of the early cognitive decline that often precedes the neurodegenerative phases in MS patients. In particular, it has been reported that inflammation enhances excitatory synaptic transmission while it decreases GABAergic transmission in vitro and ex vivo. This evidence points to the idea that an excitation/inhibition imbalance occurs in the inflamed MS brain, even though the exact molecular mechanisms leading to this synaptic dysfunction are as yet not completely clear. Along this line, we observed that acute treatment of primary hippocampal neurons in culture with pro-inflammatory cytokines leads to an increased phosphorylation of synapsin I (SynI) by ERK1/2 kinase and to an increase in the frequency of spontaneous synaptic vesicle release events, which is prevented by SynI deletion. In vivo, the ablation of SynI expression is protective in terms of disease progression and neuronal damage in the experimental autoimmune encephalomyelitis mouse model of MS. Our results point to a possible key role in MS pathogenesis of the neuronal protein SynI, a regulator of excitation/inhibition balance in neuronal networks.
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Affiliation(s)
- Fabrizia C Guarnieri
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy; Vita-Salute San Raffaele University, Via Olgettina 58, 20132 Milan, Italy
| | - Serena Bellani
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Latefa Yekhlef
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Andrea Bergamaschi
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Annamaria Finardi
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Riccardo Fesce
- Centre of Neuroscience and DISTA, University of Insubria, Via Ravasi 2, 21100 Varese, Italy
| | - Davide Pozzi
- Humanitas Clinical and Research Centre, Via Manzoni 113, 20089 Rozzano, Milan, Italy
| | - Elena Monzani
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Eugenio F Fornasiero
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Michela Matteoli
- Humanitas Clinical and Research Centre, Via Manzoni 113, 20089 Rozzano, Milan, Italy; CNR Institute of Neuroscience, via Vanvitelli 32, 20129 Milan, Italy
| | - Gianvito Martino
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy; Vita-Salute San Raffaele University, Via Olgettina 58, 20132 Milan, Italy
| | - Roberto Furlan
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Stefano Taverna
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Luca Muzio
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy
| | - Flavia Valtorta
- Division of Neuroscience, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milan, Italy; Vita-Salute San Raffaele University, Via Olgettina 58, 20132 Milan, Italy.
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43
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Meta-Analysis of MicroRNAs Dysregulated in the Hippocampal Dentate Gyrus of Animal Models of Epilepsy. eNeuro 2017; 4:eN-NWR-0152-17. [PMID: 29291240 PMCID: PMC5745610 DOI: 10.1523/eneuro.0152-17.2017] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2017] [Revised: 11/21/2017] [Accepted: 11/22/2017] [Indexed: 12/12/2022] Open
Abstract
The identification of mechanisms transforming normal to seizure-generating tissue after brain injury is key to developing new antiepileptogenic treatments. MicroRNAs (miRNAs) may act as regulators and potential treatment targets for epileptogenesis. Here, we undertook a meta-analysis of changes in miRNA expression in the hippocampal dentate gyrus (DG) following an epileptogenic insult in three epilepsy models. We identified 26 miRNAs significantly differentially expressed during epileptogenesis, and five differentially expressed in chronic epilepsy. Of these, 13 were not identified in any of the individual studies. To assess the role of these miRNAs, we predicted their mRNA targets and then filtered the list to include only target genes expressed in DG and negatively correlated with miRNA expression. Functional enrichment analysis of mRNA targets of miRNAs dysregulated during epileptogenesis suggested a role for molecular processes related to inflammation and synaptic function. Our results identify new miRNAs associated with epileptogenesis from existing data, highlighting the utility of meta-analysis in maximizing value from preclinical data.
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44
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Liu A, Zhang Y, Han L, He G, Xie W, Zhou Z, Jia Z. Regulation of Neurotransmitter Release by Amyloid Precursor Protein Through Synapsin Phosphorylation. Neurochem Res 2017; 44:683-691. [PMID: 29052089 DOI: 10.1007/s11064-017-2418-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2017] [Revised: 10/01/2017] [Accepted: 10/09/2017] [Indexed: 12/19/2022]
Abstract
Abnormal processing of amyloid precursor protein (APP) and aggregation of the Aβ peptide are known to play a key role in the pathogenesis of Alzheimer disease, but the function of endogenous APP under normal physiological conditions remains poorly understood. In this study, we investigated presynaptic changes in APP knockout (KO) mice. We demonstrate that both sucrose-induced neurotransmission and synaptic depletion in response to high frequency stimulation are significantly enhanced in APP KO compared to wild type littermates. In addition, the level of phosphorylated forms of synapsins, but not total synapsins, is elevated in the KO mice. Furthermore, we show that the inhibition of L-type calcium channels normalizes phosphorylated synapsins and slows down the high frequency induced synaptic depletion in APP KO mice. These results suggest a new mechanism by which APP regulates synaptic vesicle dynamics through synapsin-dependent phosphorylation.
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Affiliation(s)
- An Liu
- Institute of Life Sciences, The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing, 210096, China
| | - Ying Zhang
- Institute of Life Sciences, The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing, 210096, China
| | - Lifang Han
- Institute of Life Sciences, The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing, 210096, China
| | - Guiqin He
- Institute of Life Sciences, The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing, 210096, China
| | - Wei Xie
- Institute of Life Sciences, The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing, 210096, China
| | - Zikai Zhou
- Institute of Life Sciences, The Key Laboratory of Developmental Genes and Human Disease, Jiangsu Co-innovation Center of Neuroregeneration, Southeast University, Nanjing, 210096, China
| | - Zhengping Jia
- Neurosciences & Mental Health, the Hospital for Sick Children, 555 University Ave., Toronto, ON, M5G 1X8, Canada. .,Department of Physiology, Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
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45
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Valente P, Farisello P, Valtorta F, Baldelli P, Benfenati F. Impaired GABA B-mediated presynaptic inhibition increases excitatory strength and alters short-term plasticity in synapsin knockout mice. Oncotarget 2017; 8:90061-90076. [PMID: 29163811 PMCID: PMC5685732 DOI: 10.18632/oncotarget.21405] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Accepted: 09/03/2017] [Indexed: 11/25/2022] Open
Abstract
Synapsins are a family of synaptic vesicle phosphoproteins regulating synaptic transmission and plasticity. SYN1/2 genes are major epilepsy susceptibility genes in humans. Consistently, synapsin I/II/III triple knockout (TKO) mice are epileptic and exhibit severe impairments in phasic and tonic GABAergic inhibition that precede the appearance of the epileptic phenotype. These changes are associated with an increased strength of excitatory transmission that has never been mechanistically investigated. Here, we observed that an identical effect in excitatory transmission could be induced in wild-type (WT) Schaffer collateral-CA1 pyramidal cell synapses by blockade of GABAB receptors (GABABRs). The same treatment was virtually ineffective in TKO slices, suggesting that the increased strength of the excitatory transmission results from an impairment of GABAB presynaptic inhibition. Exogenous stimulation of GABABRs in excitatory autaptic neurons, where GABA spillover is negligible, demonstrated that GABABRs were effective in inhibiting excitatory transmission in both WT and TKO neurons. These results demonstrate that the decreased GABA release and spillover, previously observed in TKO hippocampal slices, removes the tonic brake of presynaptic GABABRs on glutamate transmission, making the excitation/inhibition imbalance stronger.
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Affiliation(s)
- Pierluigi Valente
- Department of Experimental Medicine, Section of Physiology, University of Genoa, 16132 Genova, Italy
| | - Pasqualina Farisello
- Department of Experimental Medicine, Section of Physiology, University of Genoa, 16132 Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Flavia Valtorta
- S. Raffaele Scientific Institute and Vita-Salute University, 20132 Milano, Italy
| | - Pietro Baldelli
- Department of Experimental Medicine, Section of Physiology, University of Genoa, 16132 Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
| | - Fabio Benfenati
- Department of Experimental Medicine, Section of Physiology, University of Genoa, 16132 Genova, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, 16132 Genova, Italy
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46
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Gervin K, Nordeng H, Ystrom E, Reichborn-Kjennerud T, Lyle R. Long-term prenatal exposure to paracetamol is associated with DNA methylation differences in children diagnosed with ADHD. Clin Epigenetics 2017; 9:77. [PMID: 28785368 PMCID: PMC5540511 DOI: 10.1186/s13148-017-0376-9] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2017] [Accepted: 07/21/2017] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Epidemiological studies have shown that long-term exposure to paracetamol during pregnancy is associated with attention-deficit/hyperactivity disorder (ADHD). The mechanism by which paracetamol may modulate the increased risk of developing ADHD is currently unknown. We have conducted an epigenome-wide association study (n = 384 cord blood samples) and investigated whether prenatal exposure to paracetamol is associated with DNA methylation in children diagnosed with ADHD. RESULTS Analyses identified significant differences in DNA methylation (n = 6211 CpGs) associated with prenatal exposure to paracetamol for more than 20 days in children diagnosed with ADHD compared to controls. In addition, these samples were differentially methylated compared to samples with ADHD exposed to paracetamol for less than 20 days (n = 2089 CpGs) and not exposed to paracetamol (n = 193 CpGs). Interestingly, several of the top genes ranked according to significance and effect size have been linked to ADHD, neural development, and neurotransmission. Gene ontology analysis revealed enrichment of pathways involved in oxidative stress, neurological processes, and the olfactory sensory system, which have previously been implicated in the etiology of ADHD. CONCLUSIONS These initial findings suggest that in individuals susceptible to ADHD, prenatal long-term exposure to paracetamol is associated with DNA methylation differences compared to controls.
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Affiliation(s)
- Kristina Gervin
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway
- PharmaTox Strategic Research Initiative, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
- Pharmacoepidemiology and Drug Safety Research Group, Department of Pharmacy, School of Pharmacy, University of Oslo, Oslo, Norway
| | - Hedvig Nordeng
- PharmaTox Strategic Research Initiative, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
- Pharmacoepidemiology and Drug Safety Research Group, Department of Pharmacy, School of Pharmacy, University of Oslo, Oslo, Norway
- Department of Child Health, Norwegian Institute of Public Health, Oslo, Norway
| | - Eivind Ystrom
- Department of Child Health, Norwegian Institute of Public Health, Oslo, Norway
- Department of Mental Disorders, Norwegian Institute of Public Health, Oslo, Norway
- Department of Psychology, University of Oslo, Oslo, Norway
| | - Ted Reichborn-Kjennerud
- Department of Child Health, Norwegian Institute of Public Health, Oslo, Norway
- Institute of Clinical Medicine, University of Oslo, Oslo, Norway
| | - Robert Lyle
- Department of Medical Genetics, Oslo University Hospital and University of Oslo, Oslo, Norway
- PharmaTox Strategic Research Initiative, Faculty of Mathematics and Natural Sciences, University of Oslo, Oslo, Norway
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47
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Synapsin Isoforms Regulating GABA Release from Hippocampal Interneurons. J Neurosci 2017; 36:6742-57. [PMID: 27335405 DOI: 10.1523/jneurosci.0011-16.2016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 05/13/2016] [Indexed: 01/02/2023] Open
Abstract
UNLABELLED Although synapsins regulate GABA release, it is unclear which synapsin isoforms are involved. We identified the synapsin isoforms that regulate GABA release via rescue experiments in cultured hippocampal neurons from synapsin I, II, and III triple knock-out (TKO) mice. In situ hybridization indicated that five different synapsin isoforms are expressed in hippocampal interneurons. Evoked IPSC amplitude was reduced in TKO neurons compared with triple wild-type neurons and was rescued by introducing any of the five synapsin isoforms. This contrasts with hippocampal glutamatergic terminals, where only synapsin IIa rescues the TKO phenotype. Deconvolution analysis indicated that the duration of GABA release was prolonged in TKO neurons and this defect in release kinetics was rescued by each synapsin isoform, aside from synapsin IIIa. Because release kinetics remained slow, whereas peak release rate was rescued, there was a 2-fold increase in GABA release in TKO neurons expressing synapsin IIIa. TKO neurons expressing individual synapsin isoforms showed normal depression kinetics aside from more rapid depression in neurons expressing synapsin IIIa. Measurements of the cumulative amount of GABA released during repetitive stimulation revealed that the rate of mobilization of vesicles from the reserve pool to the readily releasable pool and the size of the readily releasable pool of GABAergic vesicles were unaffected by synapsins. Instead, synapsins regulate release of GABA from the readily releasable pool, with all isoforms aside from synapsin IIIa controlling release synchrony. These results indicate that synapsins play fundamentally distinct roles at different types of presynaptic terminals. SIGNIFICANCE STATEMENT Synapsins are a family of proteins that regulate synaptic vesicle (SV) trafficking within nerve terminals. Here, we demonstrate that release of the inhibitory neurotransmitter GABA is supported by many different synapsin types. This contrasts with the release of other neurotransmitters, which typically is supported by only one type of synapsin. We also found that synapsins serve to synchronize the release of GABA in response to presynaptic action potentials, which is different from the synapsin-dependent trafficking of SVs in other nerve terminals. Our results establish that different synapsins play fundamentally different roles at nerve terminals releasing different types of neurotransmitters. This is an important clue to understanding how neurons release their neurotransmitters, a process essential for normal brain function.
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48
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Heise C, Taha E, Murru L, Ponzoni L, Cattaneo A, Guarnieri FC, Montani C, Mossa A, Vezzoli E, Ippolito G, Zapata J, Barrera I, Ryazanov AG, Cook J, Poe M, Stephen MR, Kopanitsa M, Benfante R, Rusconi F, Braida D, Francolini M, Proud CG, Valtorta F, Passafaro M, Sala M, Bachi A, Verpelli C, Rosenblum K, Sala C. eEF2K/eEF2 Pathway Controls the Excitation/Inhibition Balance and Susceptibility to Epileptic Seizures. Cereb Cortex 2017; 27:2226-2248. [PMID: 27005990 DOI: 10.1093/cercor/bhw075] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Alterations in the balance of inhibitory and excitatory synaptic transmission have been implicated in the pathogenesis of neurological disorders such as epilepsy. Eukaryotic elongation factor 2 kinase (eEF2K) is a highly regulated, ubiquitous kinase involved in the control of protein translation. Here, we show that eEF2K activity negatively regulates GABAergic synaptic transmission. Indeed, loss of eEF2K increases GABAergic synaptic transmission by upregulating the presynaptic protein Synapsin 2b and α5-containing GABAA receptors and thus interferes with the excitation/inhibition balance. This cellular phenotype is accompanied by an increased resistance to epilepsy and an impairment of only a specific hippocampal-dependent fear conditioning. From a clinical perspective, our results identify eEF2K as a potential novel target for antiepileptic drugs, since pharmacological and genetic inhibition of eEF2K can revert the epileptic phenotype in a mouse model of human epilepsy.
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Affiliation(s)
| | - Elham Taha
- Sagol Department of Neurobiology, University of Haifa, Haifa, Israel.,Center for Gene Manipulation in the Brain, Natural Science Faculty, University of Haifa, Haifa, Israel
| | - Luca Murru
- CNR Neuroscience Institute, Milan, Italy
| | - Luisa Ponzoni
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | | | - Fabrizia C Guarnieri
- Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
| | | | | | - Elena Vezzoli
- CNR Neuroscience Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | | | | | - Iliana Barrera
- Sagol Department of Neurobiology and.,Center for Gene Manipulation in the Brain, Natural Science Faculty, University of Haifa, Haifa, Israel
| | - Alexey G Ryazanov
- The Department of Pharmacology, University of Medicine and Dentistry of New Jersey, Robert Wood Johnson Medical School, Piscataway, NJ 08854, USA
| | - James Cook
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Michael Poe
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Michael Rajesh Stephen
- Department of Chemistry and Biochemistry, University of Wisconsin-Milwaukee, Milwaukee, WI, USA
| | - Maksym Kopanitsa
- Synome, Babraham Research Campus, Cambridge CB22 3AT, UK.,Charles River Discovery Research Services, 70210 Kuopio, Finland
| | - Roberta Benfante
- CNR Neuroscience Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Francesco Rusconi
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Daniela Braida
- Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Maura Francolini
- CNR Neuroscience Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Christopher G Proud
- University of Southampton, Centre for Biological Sciences, Southampton SO17 1BJ, UK.,South Australian Health and Medical Research Institute and University of Adelaide, Adelaide, Australia
| | - Flavia Valtorta
- Division of Neuroscience, San Raffaele Scientific Institute and Vita-Salute University, Milan, Italy
| | - Maria Passafaro
- CNR Neuroscience Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Mariaelvina Sala
- CNR Neuroscience Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Angela Bachi
- IFOM-FIRC Institute of Molecular Oncology, Milan, Italy
| | - Chiara Verpelli
- CNR Neuroscience Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
| | - Kobi Rosenblum
- Sagol Department of Neurobiology and.,Center for Gene Manipulation in the Brain, Natural Science Faculty, University of Haifa, Haifa, Israel
| | - Carlo Sala
- CNR Neuroscience Institute, Milan, Italy, Università degli Studi di Milano, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, Università degli Studi di Milano, Milan, Italy
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49
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Synapsin II Regulation of GABAergic Synaptic Transmission Is Dependent on Interneuron Subtype. J Neurosci 2017; 37:1757-1771. [PMID: 28087765 DOI: 10.1523/jneurosci.0844-16.2016] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 12/22/2016] [Accepted: 12/31/2016] [Indexed: 11/21/2022] Open
Abstract
Synapsins are epilepsy susceptibility genes that encode phosphoproteins reversibly associated with synaptic vesicles. Synapsin II (SynII) gene deletion produces a deficit in inhibitory synaptic transmission, and this defect is thought to cause epileptic activity. We systematically investigated how SynII affects synchronous and asynchronous release components of inhibitory transmission in the CA1 region of the mouse hippocampus. We found that the asynchronous GABAergic release component is diminished in SynII-deleted (SynII(-)) slices. To investigate this defect at different interneuron subtypes, we selectively blocked either N-type or P/Q-type Ca2+ channels. SynII deletion suppressed the asynchronous release component at synapses dependent on N-type Ca2+ channels but not at synapses dependent on P/Q-type Ca2+ channels. We then performed paired double-patch recordings from inhibitory basket interneurons connected to pyramidal neurons and used cluster analysis to classify interneurons according to their spiking and synaptic parameters. We identified two cell subtypes, presumably parvalbumin (PV) and cholecystokinin (CCK) expressing basket interneurons. To validate our interneuron classification, we took advantage of transgenic animals with fluorescently labeled PV interneurons and confirmed that their spiking and synaptic parameters matched the parameters of presumed PV cells identified by the cluster analysis. The analysis of the release time course at the two interneuron subtypes demonstrated that the asynchronous release component was selectively reduced at SynII(-) CCK interneurons. In contrast, the transmission was desynchronized at SynII(-) PV interneurons. Together, our results demonstrate that SynII regulates the time course of GABAergic release, and that this SynII function is dependent on the interneuron subtype.SIGNIFICANCE STATEMENT Deletion of the neuronal protein synapsin II (SynII) leads to the development of epilepsy, probably due to impairments in inhibitory synaptic transmission. We systematically investigated SynII function at different subtypes of inhibitory neurons in the hippocampus. We discovered that SynII affects the time course of GABA release, and that this effect is interneuron subtype specific. Within one of the subtypes, SynII deficiency synchronizes the release and suppresses the asynchronous release component, while at the other subtype SynII deficiency suppresses the synchronous release component. These results reveal a new SynII function in the regulation of the time course of GABA release and demonstrate that this function is dependent on the interneuron subtype.
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50
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Michetti C, Castroflorio E, Marchionni I, Forte N, Sterlini B, Binda F, Fruscione F, Baldelli P, Valtorta F, Zara F, Corradi A, Benfenati F. The PRRT2 knockout mouse recapitulates the neurological diseases associated with PRRT2 mutations. Neurobiol Dis 2016; 99:66-83. [PMID: 28007585 PMCID: PMC5321265 DOI: 10.1016/j.nbd.2016.12.018] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Revised: 12/06/2016] [Accepted: 12/18/2016] [Indexed: 11/05/2022] Open
Abstract
Heterozygous and rare homozygous mutations in PRoline-Rich Transmembrane protein 2 (PRRT2) underlie a group of paroxysmal disorders including epilepsy, kinesigenic dyskinesia episodic ataxia and migraine. Most of the mutations lead to impaired PRRT2 expression and/or function. Recently, an important role for PRTT2 in the neurotransmitter release machinery, brain development and synapse formation has been uncovered. In this work, we have characterized the phenotype of a mouse in which the PRRT2 gene has been constitutively inactivated (PRRT2 KO). β-galactosidase staining allowed to map the regional expression of PRRT2 that was more intense in the cerebellum, hindbrain and spinal cord, while it was localized to restricted areas in the forebrain. PRRT2 KO mice are normal at birth, but display paroxysmal movements at the onset of locomotion that persist in the adulthood. In addition, adult PRRT2 KO mice present abnormal motor behaviors characterized by wild running and jumping in response to audiogenic stimuli that are ineffective in wild type mice and an increased sensitivity to the convulsive effects of pentylentetrazol. Patch-clamp electrophysiology in hippocampal and cerebellar slices revealed specific effects in the cerebellum, where PRRT2 is highly expressed, consisting in a higher excitatory strength at parallel fiber-Purkinje cell synapses during high frequency stimulation. The results show that the PRRT2 KO mouse reproduces the motor paroxysms present in the human PRRT2-linked pathology and can be proposed as an experimental model for the study of the pathogenesis of the disease as well as for testing personalized therapeutic approaches. PRRT2 is intensely expressed in cerebellum and in restricted areas of the forebrain. PRRT2 KO mice display paroxysmal movements at the onset of locomotion. PRRT2 KO mice present abnormal motor behaviors in response to audiogenic stimuli. PRRT2 KO mice are more sensitive to the convulsive effects of pentylentetrazol. PRRT2 KO mice display an altered synaptic transmission in the cerebellar cortex.
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Affiliation(s)
- Caterina Michetti
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Enrico Castroflorio
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Ivan Marchionni
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Nicola Forte
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Bruno Sterlini
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Francesca Binda
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Floriana Fruscione
- Department Head and Neck Neuroscience, Laboratory of Neurogenetics and Neuroscience, Institute G. Gaslini, Via Gerolamo Gaslini, 5, 16148 Genova, Italy
| | - Pietro Baldelli
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Flavia Valtorta
- San Raffaele Scientific Institute and Vita Salute University, Via Olgettina 58, 20132 Milano, Italy
| | - Federico Zara
- Department Head and Neck Neuroscience, Laboratory of Neurogenetics and Neuroscience, Institute G. Gaslini, Via Gerolamo Gaslini, 5, 16148 Genova, Italy
| | - Anna Corradi
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy.
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