1
|
Jaudon F, Cingolani LA. Unlocking mechanosensitivity: integrins in neural adaptation. Trends Cell Biol 2024:S0962-8924(24)00046-1. [PMID: 38514304 DOI: 10.1016/j.tcb.2024.02.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 02/22/2024] [Accepted: 02/27/2024] [Indexed: 03/23/2024]
Abstract
Mechanosensitivity extends beyond sensory cells to encompass most neurons in the brain. Here, we explore recent research on the role of integrins, a diverse family of adhesion molecules, as crucial biomechanical sensors translating mechanical forces into biochemical and electrical signals in the brain. The varied biomechanical properties of neuronal integrins, including their force-dependent conformational states and ligand interactions, dictate their specific functions. We discuss new findings on how integrins regulate filopodia and dendritic spines, shedding light on their contributions to synaptic plasticity, and explore recent discoveries on how they engage with metabotropic receptors and ion channels, highlighting their direct participation in electromechanical transduction. Finally, to facilitate a deeper understanding of these developments, we present molecular and biophysical models of mechanotransduction.
Collapse
Affiliation(s)
- Fanny Jaudon
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Lorenzo A Cingolani
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy; Center for Synaptic Neuroscience and Technology (NSYN), Fondazione Istituto Italiano di Tecnologia (IIT), 16132 Genoa, Italy.
| |
Collapse
|
2
|
Cingolani LA, Thalhammer A, Jaudon F, Muià J, Baj G. Nanoscale organization of Ca V2.1 splice isoforms at presynaptic terminals: implications for synaptic vesicle release and synaptic facilitation. Biol Chem 2023; 404:931-937. [PMID: 37658578 PMCID: PMC10695435 DOI: 10.1515/hsz-2023-0235] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 08/01/2023] [Indexed: 09/03/2023]
Abstract
The distance between CaV2.1 voltage-gated Ca2+ channels and the Ca2+ sensor responsible for vesicle release at presynaptic terminals is critical for determining synaptic strength. Yet, the molecular mechanisms responsible for a loose coupling configuration of CaV2.1 in certain synapses or developmental periods and a tight one in others remain unknown. Here, we examine the nanoscale organization of two CaV2.1 splice isoforms (CaV2.1[EFa] and CaV2.1[EFb]) at presynaptic terminals by superresolution structured illumination microscopy. We find that CaV2.1[EFa] is more tightly co-localized with presynaptic markers than CaV2.1[EFb], suggesting that alternative splicing plays a crucial role in the synaptic organization of CaV2.1 channels.
Collapse
Affiliation(s)
- Lorenzo A. Cingolani
- Department of Life Sciences, University of Trieste, via Giorgieri 5, I-34127Trieste, Italy
- Center for Synaptic Neuroscience and Technology (NSYN), Fondazione Istituto Italiano di Tecnologia (IIT), Largo Rosanna Benzi 10, I-16132Genoa, Italy
| | - Agnes Thalhammer
- Department of Life Sciences, University of Trieste, via Giorgieri 5, I-34127Trieste, Italy
- Centro Interdipartimentale di Microscopia Avanzata (CIMA), University of Trieste, via Fleming 31, I-34127Trieste, Italy
| | - Fanny Jaudon
- Department of Life Sciences, University of Trieste, via Giorgieri 5, I-34127Trieste, Italy
- IRCCS Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, I-16132Genoa, Italy
| | - Jessica Muià
- Department of Life Sciences, University of Trieste, via Giorgieri 5, I-34127Trieste, Italy
| | - Gabriele Baj
- Department of Life Sciences, University of Trieste, via Giorgieri 5, I-34127Trieste, Italy
- Centro Interdipartimentale di Microscopia Avanzata (CIMA), University of Trieste, via Fleming 31, I-34127Trieste, Italy
| |
Collapse
|
3
|
Celora L, Jaudon F, Vitale C, Cingolani LA. Regulation of dendritic spine length in corticopontine layer V pyramidal neurons by autism risk gene β3 integrin. Mol Brain 2023; 16:49. [PMID: 37296444 DOI: 10.1186/s13041-023-01031-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 04/27/2023] [Indexed: 06/12/2023] Open
Abstract
The relationship between autism spectrum disorder (ASD) and dendritic spine abnormalities is well known, but it is unclear whether the deficits relate to specific neuron types and brain regions most relevant to ASD. Recent genetic studies have identified a convergence of ASD risk genes in deep layer pyramidal neurons of the prefrontal cortex. Here, we use retrograde recombinant adeno-associated viruses to label specifically two major layer V pyramidal neuron types of the medial prefrontal cortex: the commissural neurons, which put the two cerebral hemispheres in direct communication, and the corticopontine neurons, which transmit information outside the cortex. We compare the basal dendritic spines on commissural and corticopontine neurons in WT and KO mice for the ASD risk gene Itgb3, which encodes for the cell adhesion molecule β3 integrin selectively enriched in layer V pyramidal neurons. Regardless of the genotype, corticopontine neurons had a higher ratio of stubby to mushroom spines than commissural neurons. β3 integrin affected selectively spine length in corticopontine neurons. Ablation of β3 integrin resulted in corticopontine neurons lacking long (> 2 μm) thin dendritic spines. These findings suggest that a deficiency in β3 integrin expression compromises specifically immature spines on corticopontine neurons, thereby reducing the cortical territory they can sample. Because corticopontine neurons receive extensive local and long-range excitatory inputs before relaying information outside the cortex, specific alterations in dendritic spines of corticopontine neurons may compromise the computational output of the full cortex, thereby contributing to ASD pathophysiology.
Collapse
Affiliation(s)
- Lucia Celora
- Department of Life Sciences, University of Trieste, Trieste, 34127, Italy
| | - Fanny Jaudon
- Department of Life Sciences, University of Trieste, Trieste, 34127, Italy
- IRCCS Ospedale Policlinico San Martino, Genoa, 16132, Italy
| | - Carmela Vitale
- Center for Synaptic Neuroscience and Technology (NSYN), Fondazione Istituto Italiano di Tecnologia (IIT), Genoa, 16132, Italy
| | - Lorenzo A Cingolani
- Department of Life Sciences, University of Trieste, Trieste, 34127, Italy.
- Center for Synaptic Neuroscience and Technology (NSYN), Fondazione Istituto Italiano di Tecnologia (IIT), Genoa, 16132, Italy.
| |
Collapse
|
4
|
Moretto E, Miozzo F, Longatti A, Bonnet C, Coussen F, Jaudon F, Cingolani LA, Passafaro M. The tetraspanin TSPAN5 regulates AMPAR exocytosis by interacting with the AP4 complex. eLife 2023; 12:76425. [PMID: 36795458 PMCID: PMC9934860 DOI: 10.7554/elife.76425] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Accepted: 01/25/2023] [Indexed: 02/17/2023] Open
Abstract
Intracellular trafficking of AMPA receptors is a tightly regulated process which involves several adaptor proteins, and is crucial for the activity of excitatory synapses both in basal conditions and during synaptic plasticity. We found that, in rat hippocampal neurons, an intracellular pool of the tetraspanin TSPAN5 promotes exocytosis of AMPA receptors without affecting their internalisation. TSPAN5 mediates this function by interacting with the adaptor protein complex AP4 and Stargazin and possibly using recycling endosomes as a delivery route. This work highlights TSPAN5 as a new adaptor regulating AMPA receptor trafficking.
Collapse
Affiliation(s)
- Edoardo Moretto
- Institute of Neuroscience, CNRVedano al LambroItaly,NeuroMI Milan Center for Neuroscience, University of Milano-BicoccaMilanItaly
| | | | | | - Caroline Bonnet
- University of Bordeaux, Interdisciplinary Institute for NeuroscienceBordeauxFrance
| | - Francoise Coussen
- University of Bordeaux, Interdisciplinary Institute for NeuroscienceBordeauxFrance
| | - Fanny Jaudon
- Department of Life Sciences, University of TriesteTriesteItaly,IRCCS Ospedale Policlinico San MartinoGenoaItaly
| | - Lorenzo A Cingolani
- Department of Life Sciences, University of TriesteTriesteItaly,Center for Synaptic Neuroscience and Technology (NSYN), Istituto Italiano di Tecnologia (IIT)GenoaItaly
| | - Maria Passafaro
- Institute of Neuroscience, CNRVedano al LambroItaly,NeuroMI Milan Center for Neuroscience, University of Milano-BicoccaMilanItaly
| |
Collapse
|
5
|
Jaudon F, Thalhammer A, Zentilin L, Cingolani LA. CRISPR-mediated activation of autism gene Itgb3 restores cortical network excitability via mGluR5 signaling. Molecular Therapy - Nucleic Acids 2022; 29:462-480. [PMID: 36035754 PMCID: PMC9382421 DOI: 10.1016/j.omtn.2022.07.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 07/15/2022] [Indexed: 01/12/2023]
Abstract
Many mutations in autism spectrum disorder (ASD) affect a single allele, indicating a key role for gene dosage in ASD susceptibility. Recently, haplo-insufficiency of ITGB3, the gene encoding the extracellular matrix receptor β3 integrin, was associated with ASD. Accordingly, Itgb3 knockout (KO) mice exhibit autism-like phenotypes. The pathophysiological mechanisms of Itgb3 remain, however, unknown, and the potential of targeting this gene for developing ASD therapies uninvestigated. By combining molecular, biochemical, imaging, and pharmacological analyses, we establish that Itgb3 haplo-insufficiency impairs cortical network excitability by promoting extra-synaptic over synaptic signaling of the metabotropic glutamate receptor mGluR5, which is similarly dysregulated in fragile X syndrome, the most frequent monogenic form of ASD. To assess the therapeutic potential of regulating Itgb3 gene dosage, we implemented CRISPR activation and compared its efficacy with that of a pharmacological rescue strategy for fragile X syndrome. Correction of neuronal Itgb3 haplo-insufficiency by CRISPR activation rebalanced network excitability as effectively as blockade of mGluR5 with the selective antagonist MPEP. Our findings reveal an unexpected functional interaction between two ASD genes, thereby validating the pathogenicity of ITGB3 haplo-insufficiency. Further, they pave the way for exploiting CRISPR activation as gene therapy for normalizing gene dosage and network excitability in ASD.
Collapse
Affiliation(s)
- Fanny Jaudon
- Center for Synaptic Neuroscience and Technology (NSYN), Fondazione Istituto Italiano di Tecnologia (IIT), 16132 Genoa, Italy
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy
| | - Agnes Thalhammer
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Lorena Zentilin
- AAV Vector Unit, International Centre for Genetic Engineering and Biotechnology (ICGEB), 34149 Trieste, Italy
| | - Lorenzo A. Cingolani
- Center for Synaptic Neuroscience and Technology (NSYN), Fondazione Istituto Italiano di Tecnologia (IIT), 16132 Genoa, Italy
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy
- Corresponding author Lorenzo A. Cingolani, Department of Life Sciences, University of Trieste, 34127 Trieste, Italy.
| |
Collapse
|
6
|
Riccardi S, Cingolani LA, Jaudon F. CRISPR-Mediated Activation of αV Integrin Subtypes Promotes Neuronal Differentiation of Neuroblastoma Neuro2a Cells. Front Genome Ed 2022; 4:846669. [PMID: 35498157 PMCID: PMC9039181 DOI: 10.3389/fgeed.2022.846669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Accepted: 03/22/2022] [Indexed: 11/13/2022] Open
Abstract
Neuronal differentiation is a complex process whose dysfunction can lead to brain disorders. The development of new tools to target specific steps in the neuronal differentiation process is of paramount importance for a better understanding of the molecular mechanisms involved, and ultimately for developing effective therapeutic strategies for neurodevelopmental disorders. Through their interactions with extracellular matrix proteins, the cell adhesion molecules of the integrin family play essential roles in the formation of functional neuronal circuits by regulating cell migration, neurite outgrowth, dendritic spine formation and synaptic plasticity. However, how different integrin receptors contribute to the successive phases of neuronal differentiation remains to be elucidated. Here, we implemented a CRISPR activation system to enhance the endogenous expression of specific integrin subunits in an in vitro model of neuronal differentiation, the murine neuroblastoma Neuro2a cell line. By combining CRISPR activation with morphological and RT-qPCR analyses, we show that integrins of the αV family are powerful inducers of neuronal differentiation. Further, we identify a subtype-specific role for αV integrins in controlling neurite outgrowth. While αVβ3 integrin initiates neuronal differentiation of Neuro2a cells under proliferative conditions, αVβ5 integrin appears responsible for promoting a complex arborization in cells already committed to differentiation. Interestingly, primary neurons exhibit a complementary expression pattern for β3 and β5 integrin subunits during development. Our findings reveal the existence of a developmental switch between αV integrin subtypes during differentiation and suggest that a timely controlled modulation of the expression of αV integrins by CRISPRa provides a means to promote neuronal differentiation.
Collapse
Affiliation(s)
- Sara Riccardi
- Department of Life Sciences, University of Trieste, Trieste, Italy
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Lorenzo A. Cingolani
- Department of Life Sciences, University of Trieste, Trieste, Italy
- Center for Synaptic Neuroscience and Technology (NSYN), Istituto Italiano di Tecnologia (IIT), Genoa, Italy
- *Correspondence: Lorenzo A. Cingolani, ; Fanny Jaudon,
| | - Fanny Jaudon
- Department of Life Sciences, University of Trieste, Trieste, Italy
- IRCCS Ospedale Policlinico San Martino, Genoa, Italy
- *Correspondence: Lorenzo A. Cingolani, ; Fanny Jaudon,
| |
Collapse
|
7
|
Ferrante D, Sterlini B, Prestigio C, Marte A, Corradi A, Onofri F, Tortarolo G, Vicidomini G, Petretto A, Muià J, Thalhammer A, Valente P, Cingolani LA, Benfenati F, Baldelli P. PRRT2 modulates presynaptic Ca 2+ influx by interacting with P/Q-type channels. Cell Rep 2021; 35:109248. [PMID: 34133925 PMCID: PMC8220258 DOI: 10.1016/j.celrep.2021.109248] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2020] [Revised: 04/07/2021] [Accepted: 05/24/2021] [Indexed: 12/28/2022] Open
Abstract
Loss-of-function mutations in proline-rich transmembrane protein-2 (PRRT2) cause paroxysmal disorders associated with defective Ca2+ dependence of glutamatergic transmission. We find that either acute or constitutive PRRT2 deletion induces a significant decrease in the amplitude of evoked excitatory postsynaptic currents (eEPSCs) that is insensitive to extracellular Ca2+ and associated with a reduced contribution of P/Q-type Ca2+ channels to the EPSC amplitude. This synaptic phenotype parallels a decrease in somatic P/Q-type Ca2+ currents due to a decreased membrane targeting of the channel with unchanged total expression levels. Co-immunoprecipitation, pull-down assays, and proteomics reveal a specific and direct interaction of PRRT2 with P/Q-type Ca2+ channels. At presynaptic terminals lacking PRRT2, P/Q-type Ca2+ channels reduce their clustering at the active zone, with a corresponding decrease in the P/Q-dependent presynaptic Ca2+ signal. The data highlight the central role of PRRT2 in ensuring the physiological Ca2+ sensitivity of the release machinery at glutamatergic synapses.
Collapse
Affiliation(s)
- Daniele Ferrante
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Bruno Sterlini
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Cosimo Prestigio
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy
| | - Antonella Marte
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Anna Corradi
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Franco Onofri
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Giorgio Tortarolo
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Via Enrico Melen, 83B, 16152, Genova, Italy
| | - Giuseppe Vicidomini
- Molecular Microscopy and Spectroscopy, Istituto Italiano di Tecnologia, Via Enrico Melen, 83B, 16152, Genova, Italy
| | - Andrea Petretto
- Core Facilities-Clinical Proteomics and Metabolomics, IRCCS, Istituto Giannina Gaslini, Via Gerolamo Gaslini 5, 16147 Genova, Italy
| | - Jessica Muià
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Agnes Thalhammer
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Pierluigi Valente
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy
| | - Lorenzo A Cingolani
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; Department of Life Sciences, University of Trieste, Trieste, Italy
| | - Fabio Benfenati
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Largo Rosanna Benzi 10, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy.
| | - Pietro Baldelli
- Department of Experimental Medicine, University of Genova, Viale Benedetto XV, 3, 16132 Genova, Italy; IRCCS, Ospedale Policlinico San Martino, Largo Rosanna Benzi 10, 16132 Genova, Italy.
| |
Collapse
|
8
|
Letellier M, Cingolani LA. Editorial: Homeostatic Synaptic Plasticity: From Synaptic Circuit Assembly to Neurological Disorders. Front Cell Neurosci 2021; 15:695313. [PMID: 34054435 PMCID: PMC8160234 DOI: 10.3389/fncel.2021.695313] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 04/20/2021] [Indexed: 12/03/2022] Open
Affiliation(s)
- Mathieu Letellier
- University of Bordeaux, CNRS, Interdisciplinary Institute for Neuroscience, IINS, UMR 5297, Bordeaux, France
| | - Lorenzo A Cingolani
- Department of Life Sciences, University of Trieste, Trieste, Italy.,Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genoa, Italy
| |
Collapse
|
9
|
Jaudon F, Baldassari S, Musante I, Thalhammer A, Zara F, Cingolani LA. Targeting Alternative Splicing as a Potential Therapy for Episodic Ataxia Type 2. Biomedicines 2020; 8:E332. [PMID: 32899500 PMCID: PMC7555146 DOI: 10.3390/biomedicines8090332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2020] [Revised: 09/01/2020] [Accepted: 09/04/2020] [Indexed: 12/26/2022] Open
Abstract
Episodic ataxia type 2 (EA2) is an autosomal dominant neurological disorder characterized by paroxysmal attacks of ataxia, vertigo, and nausea that usually last hours to days. It is caused by loss-of-function mutations in CACNA1A, the gene encoding the pore-forming α1 subunit of P/Q-type voltage-gated Ca2+ channels. Although pharmacological treatments, such as acetazolamide and 4-aminopyridine, exist for EA2, they do not reduce or control the symptoms in all patients. CACNA1A is heavily spliced and some of the identified EA2 mutations are predicted to disrupt selective isoforms of this gene. Modulating splicing of CACNA1A may therefore represent a promising new strategy to develop improved EA2 therapies. Because RNA splicing is dysregulated in many other genetic diseases, several tools, such as antisense oligonucleotides, trans-splicing, and CRISPR-based strategies, have been developed for medical purposes. Here, we review splicing-based strategies used for genetic disorders, including those for Duchenne muscular dystrophy, spinal muscular dystrophy, and frontotemporal dementia with Parkinsonism linked to chromosome 17, and discuss their potential applicability to EA2.
Collapse
Affiliation(s)
- Fanny Jaudon
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy;
| | - Simona Baldassari
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy; (S.B.); (I.M.); (F.Z.)
| | - Ilaria Musante
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy; (S.B.); (I.M.); (F.Z.)
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, 16126 Genoa, Italy
| | - Agnes Thalhammer
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia (IIT), 16132 Genoa, Italy;
- IRCCS Ospedale Policlinico San Martino, 16132 Genoa, Italy
| | - Federico Zara
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy; (S.B.); (I.M.); (F.Z.)
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, 16126 Genoa, Italy
| | - Lorenzo A. Cingolani
- Department of Life Sciences, University of Trieste, 34127 Trieste, Italy;
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia (IIT), 16132 Genoa, Italy;
| |
Collapse
|
10
|
Jaudon F, Thalhammer A, Cingolani LA. Integrin adhesion in brain assembly: From molecular structure to neuropsychiatric disorders. Eur J Neurosci 2020; 53:3831-3850. [PMID: 32531845 DOI: 10.1111/ejn.14859] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Revised: 05/21/2020] [Accepted: 06/02/2020] [Indexed: 02/07/2023]
Abstract
Integrins are extracellular matrix receptors that mediate biochemical and mechanical bi-directional signals between the extracellular and intracellular environment of a cell thanks to allosteric conformational changes. In the brain, they are found in both neurons and glial cells, where they play essential roles in several aspects of brain development and function, such as cell migration, axon guidance, synaptogenesis, synaptic plasticity and neuro-inflammation. Although there are many successful examples of how regulating integrin adhesion and signaling can be used for therapeutic purposes, for example for halting tumor progression, this is not the case for the brain, where the growing evidence of the importance of integrins for brain pathophysiology has not translated yet into medical applications. Here, we review recent literature showing how alterations in integrin structure, expression and signaling may be involved in the etiology of autism spectrum disorder, epilepsy, schizophrenia, addiction, depression and Alzheimer's disease. We focus on common mechanisms and recurrent signaling pathways, trying to bridge studies on the genetics and molecular structure of integrins with those on synaptic physiology and brain pathology. Further, we discuss integrin-targeting strategies and their potential benefits for therapeutic purposes in neuropsychiatric disorders.
Collapse
Affiliation(s)
- Fanny Jaudon
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia (IIT), Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Agnes Thalhammer
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia (IIT), Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Lorenzo A Cingolani
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia (IIT), Genoa, Italy.,Department of Life Sciences, University of Trieste, Trieste, Italy
| |
Collapse
|
11
|
Thalhammer A, Jaudon F, Cingolani LA. Emerging Roles of Activity-Dependent Alternative Splicing in Homeostatic Plasticity. Front Cell Neurosci 2020; 14:104. [PMID: 32477067 PMCID: PMC7235277 DOI: 10.3389/fncel.2020.00104] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2020] [Accepted: 04/06/2020] [Indexed: 12/25/2022] Open
Abstract
Homeostatic plasticity refers to the ability of neuronal networks to stabilize their activity in the face of external perturbations. Most forms of homeostatic plasticity ultimately depend on changes in the expression or activity of ion channels and synaptic proteins, which may occur at the gene, transcript, or protein level. The most extensively investigated homeostatic mechanisms entail adaptations in protein function or localization following activity-dependent posttranslational modifications. Numerous studies have also highlighted how homeostatic plasticity can be achieved by adjusting local protein translation at synapses or transcription of specific genes in the nucleus. In comparison, little attention has been devoted to whether and how alternative splicing (AS) of pre-mRNAs underlies some forms of homeostatic plasticity. AS not only expands proteome diversity but also contributes to the spatiotemporal dynamics of mRNA transcripts. Prominent in the brain where it can be regulated by neuronal activity, it is a flexible process, tightly controlled by a multitude of factors. Given its extensive use and versatility in optimizing the function of ion channels and synaptic proteins, we argue that AS is ideally suited to achieve homeostatic control of neuronal output. We support this thesis by reviewing emerging evidence linking AS to various forms of homeostatic plasticity: homeostatic intrinsic plasticity, synaptic scaling, and presynaptic homeostatic plasticity. Further, we highlight the relevance of this connection for brain pathologies.
Collapse
Affiliation(s)
- Agnes Thalhammer
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia (IIT), Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Fanny Jaudon
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia (IIT), Genoa, Italy.,IRCCS Ospedale Policlinico San Martino, Genoa, Italy
| | - Lorenzo A Cingolani
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia (IIT), Genoa, Italy.,Department of Life Sciences, University of Trieste, Trieste, Italy
| |
Collapse
|
12
|
Cingolani LA, Vitale C, Dityatev A. Intra- and Extracellular Pillars of a Unifying Framework for Homeostatic Plasticity: A Crosstalk Between Metabotropic Receptors and Extracellular Matrix. Front Cell Neurosci 2019; 13:513. [PMID: 31803023 PMCID: PMC6877475 DOI: 10.3389/fncel.2019.00513] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2019] [Accepted: 10/29/2019] [Indexed: 11/18/2022] Open
Abstract
In the face of chronic changes in incoming sensory inputs, neuronal networks are capable of maintaining stable conditions of electrical activity over prolonged periods of time by adjusting synaptic strength, to amplify or dampen incoming inputs [homeostatic synaptic plasticity (HSP)], or by altering the intrinsic excitability of individual neurons [homeostatic intrinsic plasticity (HIP)]. Emerging evidence suggests a synergistic interplay between extracellular matrix (ECM) and metabotropic receptors in both forms of homeostatic plasticity. Activation of dopaminergic, serotonergic, or glutamate metabotropic receptors stimulates intracellular signaling through calmodulin-dependent protein kinase II, protein kinase A, protein kinase C, and inositol trisphosphate receptors, and induces changes in expression of ECM molecules and proteolysis of both ECM molecules (lecticans) and ECM receptors (NPR, CD44). The resulting remodeling of perisynaptic and synaptic ECM provides permissive conditions for HSP and plays an instructive role by recruiting additional signaling cascades, such as those through metabotropic glutamate receptors and integrins. The superimposition of all these signaling events determines intracellular and diffusional trafficking of ionotropic glutamate receptors, resulting in HSP and modulation of conditions for inducing Hebbian synaptic plasticity (i.e., metaplasticity). It also controls cell-surface delivery and activity of voltage- and Ca2+-gated ion channels, resulting in HIP. These mechanisms may modify epileptogenesis and become a target for therapeutic interventions.
Collapse
Affiliation(s)
- Lorenzo A. Cingolani
- Department of Life Sciences, University of Trieste, Trieste, Italy
- Center for Synaptic Neuroscience and Technology (NSYN), Istituto Italiano di Tecnologia, Genoa, Italy
| | - Carmela Vitale
- Center for Synaptic Neuroscience and Technology (NSYN), Istituto Italiano di Tecnologia, Genoa, Italy
- Department of Experimental Medicine, University of Genoa, Genoa, Italy
| | - Alexander Dityatev
- Molecular Neuroplasticity, German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
- Medical Faculty, Otto von Guericke University Magdeburg, Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
| |
Collapse
|
13
|
Thalhammer A, Contestabile A, Ermolyuk YS, Ng T, Volynski KE, Soong TW, Goda Y, Cingolani LA. Alternative Splicing of P/Q-Type Ca 2+ Channels Shapes Presynaptic Plasticity. Cell Rep 2018; 20:333-343. [PMID: 28700936 DOI: 10.1016/j.celrep.2017.06.055] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Revised: 06/04/2017] [Accepted: 06/21/2017] [Indexed: 12/26/2022] Open
Abstract
Alternative splicing of pre-mRNAs is prominent in the mammalian brain, where it is thought to expand proteome diversity. For example, alternative splicing of voltage-gated Ca2+ channel (VGCC) α1 subunits can generate thousands of isoforms with differential properties and expression patterns. However, the impact of this molecular diversity on brain function, particularly on synaptic transmission, which crucially depends on VGCCs, is unclear. Here, we investigate how two major splice isoforms of P/Q-type VGCCs (Cav2.1[EFa/b]) regulate presynaptic plasticity in hippocampal neurons. We find that the efficacy of P/Q-type VGCC isoforms in supporting synaptic transmission is markedly different, with Cav2.1[EFa] promoting synaptic depression and Cav2.1[EFb] synaptic facilitation. Following a reduction in network activity, hippocampal neurons upregulate selectively Cav2.1[EFa], the isoform exhibiting the higher synaptic efficacy, thus effectively supporting presynaptic homeostatic plasticity. Therefore, the balance between VGCC splice variants at the synapse is a key factor in controlling neurotransmitter release and presynaptic plasticity.
Collapse
Affiliation(s)
- Agnes Thalhammer
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova 16132, Italy
| | - Andrea Contestabile
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genova 16163, Italy
| | | | - Teclise Ng
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456, Singapore; National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore
| | | | - Tuck Wah Soong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456, Singapore; National Neuroscience Institute, 11 Jalan Tan Tock Seng, Singapore 308433, Singapore
| | - Yukiko Goda
- RIKEN Brain Science Institute, Wako, Saitama 351-0198, Japan
| | - Lorenzo A Cingolani
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia, Genova 16132, Italy.
| |
Collapse
|
14
|
Thalhammer A, Jaudon F, Cingolani LA. Combining Optogenetics with Artificial microRNAs to Characterize the Effects of Gene Knockdown on Presynaptic Function within Intact Neuronal Circuits. J Vis Exp 2018. [PMID: 29608168 PMCID: PMC5931759 DOI: 10.3791/57223] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
The purpose of this protocol is to characterize the effect of gene knockdown on presynaptic function within intact neuronal circuits. We describe a workflow on how to combine artificial microRNA (miR)-mediated RNA interference with optogenetics to achieve selective stimulation of manipulated presynaptic boutons in acute brain slices. The experimental approach involves the use of a single viral construct and a single neuron-specific promoter to drive the expression of both an optogenetic probe and artificial miR(s) against presynaptic gene(s). When stereotactically injected in the brain region of interest, the expressed construct makes it possible to stimulate with light exclusively the neurons with reduced expression of the gene(s) under investigation. This strategy does not require the development and maintenance of genetically modified mouse lines and can in principle be applied to other organisms and to any neuronal gene of choice. We have recently applied it to investigate how the knockdown of alternative splice isoforms of presynaptic P/Q-type voltage-gated calcium channels (VGCCs) regulates short-term synaptic plasticity at CA3 to CA1 excitatory synapses in acute hippocampal slices. A similar approach could also be used to manipulate and probe the neuronal circuitry in vivo.
Collapse
Affiliation(s)
- Agnes Thalhammer
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia
| | - Fanny Jaudon
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia
| | - Lorenzo A Cingolani
- Center for Synaptic Neuroscience and Technology, Istituto Italiano di Tecnologia;
| |
Collapse
|
15
|
Korotchenko S, Cingolani LA, Kuznetsova T, Bologna LL, Chiappalone M, Dityatev A. Modulation of network activity and induction of homeostatic synaptic plasticity by enzymatic removal of heparan sulfates. Philos Trans R Soc Lond B Biol Sci 2015; 369:20140134. [PMID: 25225107 DOI: 10.1098/rstb.2014.0134] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Heparan sulfates (HSs) are complex and highly active molecules that are required for synaptogenesis and long-term potentiation. A deficit in HSs leads to autistic phenotype in mice. Here, we investigated the long-term effect of heparinase I, which digests highly sulfated HSs, on the spontaneous bioelectrical activity of neuronal networks in developing primary hippocampal cultures. We found that chronic heparinase treatment led to a significant reduction of the mean firing rate of neurons, particularly during the period of maximal neuronal activity. Furthermore, firing pattern in heparinase-treated cultures often appeared as epileptiform bursts, with long periods of inactivity between them. These changes in network activity were accompanied by an increase in the frequency and amplitude of miniature postsynaptic excitatory currents, which could be described by a linear up-scaling of current amplitudes. Biochemically, we observed an upregulation in the expression of the glutamate receptor subunit GluA1, but not GluA2, and a strong increase in autophosphorylation of α and β Ca(2+)/calmodulin-dependent protein kinase II (CaMKII), without changes in the levels of kinase expression. These data suggest that a deficit in HSs triggers homeostatic synaptic plasticity and drastically affects functional maturation of neural network.
Collapse
Affiliation(s)
- Svetlana Korotchenko
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genoa, Italy Laboratory for Brain ECM Research, State University of Nizhny Novgorod, 603950 Nizhny Novgorod, Russia
| | - Lorenzo A Cingolani
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genoa, Italy
| | - Tatiana Kuznetsova
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genoa, Italy
| | - Luca Leonardo Bologna
- INSERM, U968, Paris 75012, France Sorbonne Universités, UPMC Univ Paris 06, UMR_S 968, Institut de la Vision, Paris 75012, France CNRS, UMR_7210, Paris 75012, France
| | - Michela Chiappalone
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genoa, Italy
| | - Alexander Dityatev
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, via Morego 30, 16163 Genoa, Italy Laboratory for Brain ECM Research, State University of Nizhny Novgorod, 603950 Nizhny Novgorod, Russia Molecular Neuroplasticity Group, German Center for Neurodegenerative Diseases (DZNE), 39120 Magdeburg, Germany
| |
Collapse
|
16
|
Gymnopoulos M, Cingolani LA, Pedarzani P, Stocker M. Developmental mapping of small-conductance calcium-activated potassium channel expression in the rat nervous system. J Comp Neurol 2014; 522:1072-101. [PMID: 24096910 PMCID: PMC4016743 DOI: 10.1002/cne.23466] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 09/06/2013] [Accepted: 09/17/2013] [Indexed: 12/22/2022]
Abstract
Early electrical activity and calcium influx regulate crucial aspects of neuronal development. Small-conductance calcium-activated potassium (SK) channels regulate action potential firing and shape calcium influx through feedback regulation in mature neurons. These functions, observed in the adult nervous system, make them ideal candidates to regulate activity-and calcium-dependent processes in neurodevelopment. However, to date little is known about the onset of expression and regions expressing SK channel subunits in the embryonic and postnatal development of the central nervous system (CNS). To allow studies on the contribution of SK channels to different phases of development of single neurons and networks, we have performed a detailed in situ hybridization mapping study, providing comprehensive distribution profiles of all three SK subunits (SK1, SK2, and SK3) in the rat CNS during embryonic and postnatal development. SK channel transcripts are expressed at early stages of prenatal CNS development. The three SK channel subunits display different developmental expression gradients in distinct CNS regions, with time points of expression and up-or downregulation that can be associated with a range of diverse developmental events. Their early expression in embryonic development suggests an involvement of SK channels in the regulation of developmental processes. Additionally, this study shows how the postnatal ontogenetic patterns lead to the adult expression map for each SK channel subunit and how their coexpression in the same regions or neurons varies throughout development. J. Comp. Neurol. 522:1072–1101, 2014. © 2013 Wiley Periodicals, Inc.
Collapse
Affiliation(s)
- Marco Gymnopoulos
- Department of Molecular Biology of Neuronal Signals, Max Planck Institute for Experimental Medicine, 37075, Göttingen, Germany
| | | | | | | |
Collapse
|
17
|
Abstract
During central nervous system development, extracellular matrix (ECM) receptors and their ligands play key roles as guidance molecules, informing neurons where and when to send axonal and dendritic projections, establish connections, and form synapses between pre- and postsynaptic cells. Once stable synapses are formed, many ECM receptors transition in function to control the maintenance of stable connections between neurons and regulate synaptic plasticity. These receptors bind to and are activated by ECM ligands. In turn, ECM receptor activation modulates downstream signaling cascades that control cytoskeletal dynamics and synaptic activity to regulate neuronal structure and function and thereby impact animal behavior. The activities of cell adhesion receptors that mediate interactions between pre- and postsynaptic partners are also strongly influenced by ECM composition. This chapter highlights a number of ECM receptors, their roles in the control of synapse structure and function, and the impact of these receptors on synaptic plasticity and animal behavior.
Collapse
Affiliation(s)
- Meghan E Kerrisk
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA
| | - Lorenzo A Cingolani
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia, Genoa, Italy
| | - Anthony J Koleske
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, CT, USA; Department of Neurobiology, Yale University, New Haven, CT, USA; Interdepartmental Neuroscience Program, Yale University, New Haven, CT, USA; Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University, New Haven, CT, USA.
| |
Collapse
|
18
|
Abstract
At synapses, pre- and post-synaptic cells get in direct contact with each other via cell adhesion molecules (CAMs). Several CAMs have been identified at the neuromuscular junction and at central synapses, where they regulate synaptic strength, by recruiting scaffolding proteins, neurotransmitter receptors and synaptic vesicles in response to the binding of counter-receptors across the synaptic cleft. Many synapses are also surrounded by astrocytic processes and embedded in conspicuous extracellular matrix (ECM). It is now widely recognized that astrocytes play a central role in regulating the synaptic machinery by exchanging information with the neuronal elements via diffusible molecules and direct physical interactions; this has lead to the concept of the 'tri-partite synapse'. More recently, the term 'tetra-partite synapse' has been introduced to underlie the importance of ECM in shaping synaptic function by mediating interaction and signaling between neurons and astrocytes. Here, we will review how this integrated view of the synapse can help us understand homeostatic synaptic plasticity at the neuromuscular junction and in the central nervous system. We will explore how synaptic CAMs regulate two forms of homeostatic plasticity: (i) postsynaptic scaling of synaptic currents to counteract changes in neuronal network activity and (ii) the compensatory modulation of presynaptic neurotransmitter release in response to changes in postsynaptic efficacy. We will discuss recent findings on activity-dependent trans-synaptic signaling events and the role of cell adhesion in the feedback control of network activity. This article is part of the Special Issue entitled 'Homeostatic Synaptic Plasticity'.
Collapse
Affiliation(s)
- Agnes Thalhammer
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genoa, Italy
| | - Lorenzo A Cingolani
- Department of Neuroscience and Brain Technologies, Istituto Italiano di Tecnologia (IIT), Via Morego 30, 16163 Genoa, Italy.
| |
Collapse
|
19
|
McGeachie AB, Skrzypiec AE, Cingolani LA, Letellier M, Pawlak R, Goda Y. β3 integrin is dispensable for conditioned fear and hebbian forms of plasticity in the hippocampus. Eur J Neurosci 2012; 36:2461-9. [PMID: 22748100 DOI: 10.1111/j.1460-9568.2012.08163.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Integrins play key roles in the developing and mature nervous system, from promoting neuronal process outgrowth to facilitating synaptic plasticity. Recently, in hippocampal pyramidal neurons, β3 integrin (ITGβ3) was shown to stabilise synaptic AMPA receptors (AMPARs) and to be required for homeostatic scaling of AMPARs elicited by chronic activity suppression. To probe the physiological function for ITGβ3-dependent processes in the brain, we examined whether the loss of ITGβ3 affected fear-related behaviours in mice. ITGβ3-knockout (KO) mice showed normal conditioned fear responses that were similar to those of control wild-type mice. However, anxiety-like behaviour appeared substantially compromised and could be reversed to control levels by lentivirus-mediated re-expression of ITGβ3 bilaterally in the ventral hippocampus. In hippocampal slices, the loss of ITGβ3 activity did not compromise hebbian forms of plasticity--neither acute pharmacological disruption of ITGβ3 ligand interactions nor genetic deletion of ITGβ3 altered long-term potentiation (LTP) or long-term depression (LTD). Moreover, we did not detect any changes in short-term synaptic plasticity upon loss of ITGβ3 activity. In contrast, acutely disrupting ITGβ1-ligand interactions or genetic deletion of ITGβ1 selectively interfered with LTP stabilisation whereas LTD remained unaltered. These findings indicate a lack of requirement for ITGβ3 in the two robust forms of hippocampal long-term synaptic plasticity, LTP and LTD, and suggest differential roles for ITGβ1 and ITGβ3 in supporting hippocampal circuit functions.
Collapse
Affiliation(s)
- A B McGeachie
- Medical Research Council Laboratory for Molecular Cell Biology and Cell Biology Unit, University College London, Gower Street, London, UK
| | | | | | | | | | | |
Collapse
|
20
|
Bassani S, Cingolani LA, Valnegri P, Folci A, Zapata J, Gianfelice A, Sala C, Goda Y, Passafaro M. The X-linked intellectual disability protein TSPAN7 regulates excitatory synapse development and AMPAR trafficking. Neuron 2012; 73:1143-58. [PMID: 22445342 PMCID: PMC3314997 DOI: 10.1016/j.neuron.2012.01.021] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/03/2012] [Indexed: 11/28/2022]
Abstract
Mutations in TSPAN7—a member of the tetraspanin protein superfamily—are implicated in some forms of X-linked intellectual disability. Here we show that TSPAN7 overexpression promotes the formation of filopodia and dendritic spines in cultured hippocampal neurons from embryonic rats, whereas TSPAN7 silencing reduces head size and stability of spines and AMPA receptor currents. Via its C terminus, TSPAN7 interacts with the PDZ domain of protein interacting with C kinase 1 (PICK1), to regulate PICK1 and GluR2/3 association and AMPA receptor trafficking. These findings indicate that, in hippocampal neurons, TSPAN7 regulates AMPA receptor trafficking by limiting PICK1 accessibility to AMPA receptors and suggest an additional mechanism for the functional maturation of glutamatergic synapses, whose impairment is implicated in intellectual disability.
Collapse
Affiliation(s)
- Silvia Bassani
- CNR Institute of Neuroscience, Department of Medical Pharmacology, University of Milan, Milan 20129, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Bassani S, Cingolani LA. Tetraspanins: Interactions and interplay with integrins. Int J Biochem Cell Biol 2012; 44:703-8. [PMID: 22326999 DOI: 10.1016/j.biocel.2012.01.020] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2011] [Revised: 01/20/2012] [Accepted: 01/27/2012] [Indexed: 12/14/2022]
Abstract
Tetraspanins are small transmembrane proteins present on the cell surface of almost every eukaryotic cell. Through binding with other transmembrane and intracellular proteins, they regulate diverse cellular processes ranging from cell adhesion and motility to synapse formation and tumor progression. Here, we provide a brief overview of molecular, cellular and clinical studies to illustrate how the multiple functions of this fascinating family of molecules stem from their interplay with multiple molecular partners. In particular, we emphasize the special relationship between tetraspanins and the cell adhesion molecules integrins in regulating cell physiology in health and disease.
Collapse
Affiliation(s)
- Silvia Bassani
- CNR Institute of Neuroscience, Cellular and Molecular Pharmacology, Department of Pharmacology, University of Milan, Italy
| | | |
Collapse
|
22
|
Thalhammer A, Edgington RJ, Cingolani LA, Schoepfer R, Jackman RB. The use of nanodiamond monolayer coatings to promote the formation of functional neuronal networks. Biomaterials 2009; 31:2097-104. [PMID: 20035997 DOI: 10.1016/j.biomaterials.2009.11.109] [Citation(s) in RCA: 108] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2009] [Accepted: 11/29/2009] [Indexed: 11/19/2022]
Abstract
Nanostructured materials provide a new dimension of interaction with biological systems that takes place on a sub-cellular level with a high degree of specificity. In the field of neuroscience the nanoscale corresponds to the size of synapses; the specific connections between brain cells. In this context, diamond-based materials have attracted much attention due to their extreme mechanical and electrical properties and their chemical inertness. Here the suitability of nanodiamond (ND) monolayers to act as a platform for neuronal growth is investigated. Neurons cultured on various ND-coated substrates perform remarkably well, and similar to those grown on standard protein-coated materials with respect to their initial cell attachment, sustained neurite outgrowth, cell-autonomous neuronal excitability and functionality of the resulting electrical networks. ND layering provides an excellent growth substrate on various materials for functional neuronal networks and bypasses the necessity of protein coating, which promises great potential for chronic medical implants.
Collapse
Affiliation(s)
- Agnes Thalhammer
- Laboratory for Molecular Pharmacology, NPP, University College London, Gower Street, London, WC1E 6BT, UK
| | | | | | | | | |
Collapse
|
23
|
|
24
|
Abstract
Synapse regulation exploits the capacity of actin to function as a stable structural component or as a dynamic filament. Beyond its well-appreciated role in eliciting visible morphological changes at the synapse, the emerging picture points to an active contribution of actin to the modulation of the efficacy of pre- and postsynaptic terminals. Moreover, by engaging distinct pools of actin and divergent signalling pathways, actin-dependent morphological plasticity could be uncoupled from modulation of synaptic strength. The aim of this Review is to highlight some of the recent progress in elucidating the role of the actin cytoskeleton in synaptic function.
Collapse
Affiliation(s)
- Lorenzo A Cingolani
- MRC Laboratory for Molecular Cell Biology and MRC Cell Biology Unit, University College London, Gower Street, London, WC1E 6BT, UK
| | | |
Collapse
|
25
|
Abstract
The precise contribution of the cadherin-beta-catenin synapse adhesion complex in the functional and structural changes associated with the pre- and postsynaptic terminals remains unclear. Here we report a requirement for endogenous beta-catenin in regulating synaptic strength and dendritic spine morphology in cultured hippocampal pyramidal neurons. Ablating beta-catenin after the initiation of synaptogenesis in the postsynaptic neuron reduces the amplitude of spontaneous excitatory synaptic responses without a concurrent change in their frequency and synapse density. The normal glutamatergic synaptic response is maintained by postsynaptic beta-catenin in a cadherin-dependent manner and requires the C-terminal PDZ-binding motif of beta-catenin but not the link to the actin cytoskeleton. In addition, ablating beta-catenin in postsynaptic neurons accompanies a block of bidirectional quantal scaling of glutamatergic responses induced by chronic activity manipulation. In older cultures at a time when neurons have abundant dendritic spines, neurons ablated for beta-catenin show thin, elongated spines and reduced proportion of mushroom spines without a change in spine density. Collectively, these findings suggest that the cadherin-beta-catenin complex is an integral component of synaptic strength regulation and plays a basic role in coupling synapse function and spine morphology.
Collapse
Affiliation(s)
- Takashi Okuda
- *Medical Research Council Laboratory for Molecular Cell Biology and Cell Biology Unit
| | - Lily M. Y. Yu
- *Medical Research Council Laboratory for Molecular Cell Biology and Cell Biology Unit
- Department of Pharmacology, University College London, Gower Street, London WC1E 6BT, United Kingdom; and
| | - Lorenzo A. Cingolani
- *Medical Research Council Laboratory for Molecular Cell Biology and Cell Biology Unit
| | - Rolf Kemler
- Department of Molecular Embryology, Max Planck Institute of Immunobiology, Stuebeweg 51, D-79108 Freiburg, Germany
| | - Yukiko Goda
- *Medical Research Council Laboratory for Molecular Cell Biology and Cell Biology Unit
- Department of Pharmacology, University College London, Gower Street, London WC1E 6BT, United Kingdom; and
- To whom correspondence should be addressed at:
Medical Research Council Laboratory for Molecular Cell Biology and Cell Biology Unit, University College London, Gower Street, London WC1E 6BT, United Kingdom. E-mail:
| |
Collapse
|
26
|
Pedarzani P, Mosbacher J, Rivard A, Cingolani LA, Oliver D, Stocker M, Adelman JP, Fakler B. Control of electrical activity in central neurons by modulating the gating of small conductance Ca2+-activated K+ channels. J Biol Chem 2001; 276:9762-9. [PMID: 11134030 DOI: 10.1074/jbc.m010001200] [Citation(s) in RCA: 191] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In most central neurons, action potentials are followed by an afterhyperpolarization (AHP) that controls firing pattern and excitability. The medium and slow components of the AHP have been ascribed to the activation of small conductance Ca(2+)-activated potassium (SK) channels. Cloned SK channels are heteromeric complexes of SK alpha-subunits and calmodulin. The channels are activated by Ca(2+) binding to calmodulin that induces conformational changes resulting in channel opening, and channel deactivation is the reverse process brought about by dissociation of Ca(2+) from calmodulin. Here we show that SK channel gating is effectively modulated by 1-ethyl-2-benzimidazolinone (EBIO). Application of EBIO to cloned SK channels shifts the Ca(2+) concentration-response relation into the lower nanomolar range and slows channel deactivation by almost 10-fold. In hippocampal CA1 neurons, EBIO increased both the medium and slow AHP, strongly reducing electrical activity. Moreover, EBIO suppressed the hyperexcitability induced by low Mg(2+) in cultured cortical neurons. These results underscore the importance of SK channels for shaping the electrical response patterns of central neurons and suggest that modulating SK channel gating is a potent mechanism for controlling excitability in the central nervous system.
Collapse
Affiliation(s)
- P Pedarzani
- Max-Planck Institut für Experimentelle Medizin, 37075 Göttingen, Germany
| | | | | | | | | | | | | | | |
Collapse
|