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Feller B, Fallon A, Luo W, Nguyen PT, Shlaifer I, Lee AK, Chofflet N, Yi N, Khaled H, Karkout S, Bourgault S, Durcan TM, Takahashi H. α-Synuclein Preformed Fibrils Bind to β-Neurexins and Impair β-Neurexin-Mediated Presynaptic Organization. Cells 2023; 12:cells12071083. [PMID: 37048156 PMCID: PMC10093570 DOI: 10.3390/cells12071083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/28/2023] [Accepted: 03/31/2023] [Indexed: 04/08/2023] Open
Abstract
Synucleinopathies form a group of neurodegenerative diseases defined by the misfolding and aggregation of α-synuclein (α-syn). Abnormal accumulation and spreading of α-syn aggregates lead to synapse dysfunction and neuronal cell death. Yet, little is known about the synaptic mechanisms underlying the α-syn pathology. Here we identified β-isoforms of neurexins (β-NRXs) as presynaptic organizing proteins that interact with α-syn preformed fibrils (α-syn PFFs), toxic α-syn aggregates, but not α-syn monomers. Our cell surface protein binding assays and surface plasmon resonance assays reveal that α-syn PFFs bind directly to β-NRXs through their N-terminal histidine-rich domain (HRD) at the nanomolar range (KD: ~500 nM monomer equivalent). Furthermore, our artificial synapse formation assays show that α-syn PFFs diminish excitatory and inhibitory presynaptic organization induced by a specific isoform of neuroligin 1 that binds only β-NRXs, but not α-isoforms of neurexins. Thus, our data suggest that α-syn PFFs interact with β-NRXs to inhibit β-NRX-mediated presynaptic organization, providing novel molecular insight into how α-syn PFFs induce synaptic pathology in synucleinopathies such as Parkinson’s disease and dementia with Lewy bodies.
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Affiliation(s)
- Benjamin Feller
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada
- Department of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Aurélie Fallon
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada
- Department of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Wen Luo
- The Neuro’s Early Drug Discovery Unit (EDDU), Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada
| | - Phuong Trang Nguyen
- Department of Chemistry, Quebec Network for Research on Protein Function, Engineering and Applications, PROTEO, Université du Québec à Montréal, Montreal, QC H3C 3P8, Canada
| | - Irina Shlaifer
- The Neuro’s Early Drug Discovery Unit (EDDU), Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada
| | - Alfred Kihoon Lee
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 2B2, Canada
| | - Nicolas Chofflet
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 2B2, Canada
| | - Nayoung Yi
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada
- Department of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Husam Khaled
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada
- Department of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
| | - Samer Karkout
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada
| | - Steve Bourgault
- Department of Chemistry, Quebec Network for Research on Protein Function, Engineering and Applications, PROTEO, Université du Québec à Montréal, Montreal, QC H3C 3P8, Canada
| | - Thomas M. Durcan
- The Neuro’s Early Drug Discovery Unit (EDDU), Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, McGill University, Montreal, QC H3A 2B4, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 2B2, Canada
| | - Hideto Takahashi
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montreal, QC H2W 1R7, Canada
- Department of Medicine, Université de Montréal, Montreal, QC H3T 1J4, Canada
- Integrated Program in Neuroscience, McGill University, Montreal, QC H3A 2B2, Canada
- Division of Experimental Medicine, McGill University, Montreal, QC H3A 0G4, Canada
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2
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Kokan N, Witt S, Sandhu S, Hutter H. lron-11 guides axons in the ventral nerve cord of Caenorhabditis elegans. PLoS One 2022; 17:e0278258. [PMID: 36449480 PMCID: PMC9710760 DOI: 10.1371/journal.pone.0278258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Accepted: 11/13/2022] [Indexed: 12/02/2022] Open
Abstract
For the nervous system to develop properly, neurons must connect in a precise way to form functional networks. This requires that outgrowing neuronal processes (axons) navigate to their target areas, where they establish proper synaptic connections. The molecular basis of this navigation process is not firmly understood. A candidate family containing putative receptors acting in various aspects of neuronal development including axon navigation are transmembrane proteins of the extracellular Leucine-Rich Repeat family (eLRRs). We systematically tested members of this family in C. elegans for a role in axon navigation in the ventral nerve cord (VNC). We found that lron-11 mutants showed VNC navigation defects in several classes of neurons, including a pioneer neuron and various classes of interneurons and motoneurons. This suggests that while most members of the lron-family do not seem to have a role in axon navigation in the VNC, lron-11 is likely to be a receptor required for correct navigation of axons in the VNC of C. elegans.
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Affiliation(s)
- Nikolas Kokan
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Skyla Witt
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Saru Sandhu
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
| | - Harald Hutter
- Department of Biological Sciences, Simon Fraser University, Burnaby, BC, Canada
- * E-mail:
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Teng Z, Gottmann K. Hemisynapse Formation Between Target Astrocytes and Cortical Neuron Axons in vitro. Front Mol Neurosci 2022; 15:829506. [PMID: 35386271 PMCID: PMC8978633 DOI: 10.3389/fnmol.2022.829506] [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: 12/05/2021] [Accepted: 02/08/2022] [Indexed: 01/28/2023] Open
Abstract
One of the most fundamental organizing principles in the mammalian brain is that neurons do not establish synapses with the other major cell type, the astrocytes. However, induced synapse formation between neurons and astrocytes appears conceivable, because astrocytes are well known to express functional ionotropic glutamate receptors. Here, we attempted to trigger synapse formation between co-cultured neurons and astrocytes by overexpressing the strongly synaptogenic adhesion protein LRRTM2 in astrocytes physically contacted by cortical axons. Interestingly, control experiments with immature cortical astrocytes without any overexpression resulted in the induction of synaptic vesicle clustering in contacting axons (hemisynapse formation). This synaptogenic activity correlated with the endogenous expression of the synaptogenic protein Neuroligin1. Hemisynapse formation was further enhanced upon overexpression of LRRTM2 in cortical astrocytes. In contrast, cerebellar astrocytes required overexpression of LRRTM2 for induction of synaptic vesicle clustering in contacting axons. We further addressed, whether hemisynapse formation was accompanied by the appearance of fully functional glutamatergic synapses. We therefore attempted to record AMPA receptor-mediated miniature excitatory postsynaptic currents (mEPSCs) in innervated astrocytes using the whole-cell patch-clamp technique. Despite the endogenous expression of the AMPA receptor subunits GluA2 and to a lesser extent GluA1, we did not reliably observe spontaneous AMPA mEPSCs. In conclusion, overexpression of the synaptogenic protein LRRTM2 induced hemisynapse formation between co-cultured neurons and astrocytes. However, the formation of fully functional synapses appeared to require additional factors critical for nano-alignment of presynaptic vesicles and postsynaptic receptors.
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Blockus H, Rolotti SV, Szoboszlay M, Peze-Heidsieck E, Ming T, Schroeder A, Apostolo N, Vennekens KM, Katsamba PS, Bahna F, Mannepalli S, Ahlsen G, Honig B, Shapiro L, de Wit J, Losonczy A, Polleux F. Synaptogenic activity of the axon guidance molecule Robo2 underlies hippocampal circuit function. Cell Rep 2021; 37:109828. [PMID: 34686348 PMCID: PMC8605498 DOI: 10.1016/j.celrep.2021.109828] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 07/06/2021] [Accepted: 09/22/2021] [Indexed: 01/03/2023] Open
Abstract
Synaptic connectivity within adult circuits exhibits a remarkable degree of cellular and subcellular specificity. We report that the axon guidance receptor Robo2 plays a role in establishing synaptic specificity in hippocampal CA1. In vivo, Robo2 is present and required postsynaptically in CA1 pyramidal neurons (PNs) for the formation of excitatory (E) but not inhibitory (I) synapses, specifically in proximal but not distal dendritic compartments. In vitro approaches show that the synaptogenic activity of Robo2 involves a trans-synaptic interaction with presynaptic Neurexins, as well as binding to its canonical extracellular ligand Slit. In vivo 2-photon Ca2+ imaging of CA1 PNs during spatial navigation in awake behaving mice shows that preventing Robo2-dependent excitatory synapse formation cell autonomously during development alters place cell properties of adult CA1 PNs. Our results identify a trans-synaptic complex linking the establishment of synaptic specificity to circuit function.
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Affiliation(s)
- Heike Blockus
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Sebi V Rolotti
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Miklos Szoboszlay
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Eugénie Peze-Heidsieck
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Tiffany Ming
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Anna Schroeder
- VIB Center for Brain and Disease Research, Herestraat 49, 3000 Leuven, Belgium; Department of Neurosciences, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Nuno Apostolo
- VIB Center for Brain and Disease Research, Herestraat 49, 3000 Leuven, Belgium; Department of Neurosciences, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Kristel M Vennekens
- VIB Center for Brain and Disease Research, Herestraat 49, 3000 Leuven, Belgium; Department of Neurosciences, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Phinikoula S Katsamba
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Fabiana Bahna
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Seetha Mannepalli
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Goran Ahlsen
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA
| | - Barry Honig
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA; Department of Medicine, Columbia University, New York, NY 10032, USA
| | - Lawrence Shapiro
- Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY 10032, USA
| | - Joris de Wit
- VIB Center for Brain and Disease Research, Herestraat 49, 3000 Leuven, Belgium; Department of Neurosciences, KU Leuven, Herestraat 49, 3000 Leuven, Belgium
| | - Attila Losonczy
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA.
| | - Franck Polleux
- Department of Neuroscience, Columbia University, New York, NY 10027, USA; Zuckerman Mind Brain Behavior Institute, Columbia University, New York, NY 10027, USA; Kavli Institute for Brain Science, Columbia University, New York, NY 10027, USA.
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Hita FJ, Bekinschtein P, Ledda F, Paratcha G. Leucine-rich repeats and immunoglobulin-like domains 1 deficiency affects hippocampal dendrite complexity and impairs cognitive function. Dev Neurobiol 2021; 81:774-785. [PMID: 34114331 DOI: 10.1002/dneu.22840] [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: 03/01/2021] [Revised: 06/07/2021] [Accepted: 06/08/2021] [Indexed: 11/06/2022]
Abstract
Leucine-rich repeat (LRR) transmembrane proteins have been directly linked to neurodevelopmental and cognitive disorders. We have previously shown that the LRR transmembrane protein, leucine-rich repeats and immunoglobulin-like domains 1 (Lrig1), is a physiological regulator of dendrite complexity of hippocampal pyramidal neurons and social behavior. In this study, we performed a battery of behavioral tests to evaluate spatial memory and cognitive capabilities in Lrig1 mutant mice. The cognitive assessment demonstrated deficits in recognition and spatial memory, evaluated by novel object recognition and object location tests. Moreover, we found that Lrig1-deficient mice present specific impairments in the processing of similar but not dissimilar locations in a spatial pattern separation task, which was correlated with an enhanced dendritic growth and branching of Doublecortin-positive immature granule cells of the dentate gyrus. Altogether, these findings indicate that Lrig1 plays an essential role in controlling morphological and functional plasticity in the hippocampus.
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Affiliation(s)
- Francisco Javier Hita
- Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis"(IBCN)- CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Pedro Bekinschtein
- Instituto de Neurociencias Cognitiva y Traslacional (INCYT), Consejo Nacional de Investigaciones Científicas y Tecnológicas (CONICET), Instituto de Neurología Cognitiva (INECO), Universidad Favaloro, Buenos Aires, Argentina
| | - Fernanda Ledda
- Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis"(IBCN)- CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina.,Fundación Instituto Leloir, Instituto de Investigaciones Bioquímicas de Buenos Aires, Buenos Aires, Argentina
| | - Gustavo Paratcha
- Instituto de Biología Celular y Neurociencias "Prof. E. De Robertis"(IBCN)- CONICET-Universidad de Buenos Aires, Buenos Aires, Argentina.,Facultad de Medicina, I° U.A. Histología, Embriología, Biología Celular y Genética, Universidad de Buenos Aires, Buenos Aires, Argentina
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Zhang L, Li J, Li Y, Wang Z, Wang G, Yu Y, Song C, Cui W. Spinal caspase-3 contributes to tibial fracture-associated postoperative allodynia via up-regulation of LRRTM1 expression in mice. Neurosci Lett 2020; 739:135429. [PMID: 33069813 DOI: 10.1016/j.neulet.2020.135429] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 09/22/2020] [Accepted: 09/27/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND Bone fracture may subsequently cause chronic postoperative pain after orthopedic surgery, but mechanisms remain elusive. The necessity of caspase-3 in neuroinflammation and synaptic plasticity has been summarized in pathological pain. Leucine-rich repeat transmembrane protein 1 (LRRTM1) mediates synaptic delivery of AMPA receptor and synaptogenesis. This study evaluated whether caspase-3 and LRRTM1 are required for fracture-associated postoperative allodynia. METHODS A model of tibial fracture with intramedullary pinning in mice was established for the induction of postoperative pain, verified by measurement of mechanical paw withdrawal threshold and cold scores response to acetone. The caspase-3 specific inhibitor, recombinant caspase-3 and LRRTM1 knockdown by shRNA were utilized for the investigation of pathogenesis as well as the prevention of allodynia. Also, the activity of caspase-3 and the expression of LRRTM1 in the spinal dorsal horn were examined by Western blot and RT-qPCR. RESULTS This study reported that tibial fracture and orthopedic surgery produced long-lasting mechanical allodynia and cold allodynia, along with the up-modulation of spinal caspase-3 activity (but not caspase-3 expression) and LRRTM1 expression. Spinal caspase-3 inhibition prevented fracture-associated behavioral allodynia in a dose-dependent manner. Caspase-3 inhibitor also reduced the spinal increased LRRTM1 level after tibial fracture with pinning. Spinal LRRTM1 deficiency impaired fracture-caused postoperative pain. Intrathecal recombinant caspase-3 facilitated acute pain hypersensitivity and spinal LRRTM1 expression in naïve mice, reversing by LRRTM1 knockdown. CONCLUSION Our current results demonstrate the spinal up-regulation of LRRTM1 by caspase-3 activation in the development of tibial fracture-associated postoperative pain in mice.
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Affiliation(s)
- Linlin Zhang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin 300052, China
| | - Jing Li
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin 300052, China
| | - Yize Li
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin 300052, China
| | - Zhen Wang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin 300052, China
| | - Guolin Wang
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin 300052, China
| | - Yonghao Yu
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin 300052, China
| | - Chengcheng Song
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin 300052, China.
| | - Wei Cui
- Department of Anesthesiology, Tianjin Medical University General Hospital, Tianjin 300052, China; Tianjin Research Institute of Anesthesiology, Tianjin 300052, China.
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Tsuboi A. LRR-Containing Oncofetal Trophoblast Glycoprotein 5T4 Shapes Neural Circuits in Olfactory and Visual Systems. Front Mol Neurosci 2020; 13:581018. [PMID: 33192298 PMCID: PMC7655536 DOI: 10.3389/fnmol.2020.581018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2020] [Accepted: 09/22/2020] [Indexed: 01/19/2023] Open
Abstract
In mammals, the sensory experience can regulate the development of various brain structures, including the cortex, hippocampus, retina, and olfactory bulb (OB). Odor experience-evoked neural activity drives the development of dendrites on excitatory projection neurons in the OB, such as mitral and tufted cells, as well as inhibitory interneurons. OB interneurons are generated continuously in the subventricular zone and differentiate into granule cells (GCs) and periglomerular cells (PGCs). However, it remains unknown what role each type of OB interneuron plays in controlling olfactory behaviors. Recent studies showed that among the various types of OB interneurons, a subtype of GCs expressing oncofetal trophoblast glycoprotein 5T4 is required for simple odor detection and discrimination behaviors. Mouse 5T4 (also known as Tpbg) is a type I membrane glycoprotein whose extracellular domain contains seven leucine-rich repeats (LRRs) sandwiched between characteristic LRR-N and LRR-C regions. Recently, it was found that the developmental expression of 5T4 increases dramatically in the retina just before eye-opening. Single-cell transcriptomics further suggests that 5T4 is involved in the development and maintenance of functional synapses in a subset of retinal interneurons, including rod bipolar cells (RBCs) and amacrine cells (ACs). Collectively, 5T4, expressed in interneurons of the OB and retina, plays a key role in sensory processing in the olfactory and visual systems.
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Affiliation(s)
- Akio Tsuboi
- Graduate School of Frontier Biosciences, Osaka University, Suita, Japan
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LAR-RPTPs Directly Interact with Neurexins to Coordinate Bidirectional Assembly of Molecular Machineries. J Neurosci 2020; 40:8438-8462. [PMID: 33037075 DOI: 10.1523/jneurosci.1091-20.2020] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 08/27/2020] [Accepted: 09/30/2020] [Indexed: 11/21/2022] Open
Abstract
Neurexins (Nrxns) and LAR-RPTPs (leukocyte common antigen-related protein tyrosine phosphatases) are presynaptic adhesion proteins responsible for organizing presynaptic machineries through interactions with nonoverlapping extracellular ligands. Here, we report that two members of the LAR-RPTP family, PTPσ and PTPδ, are required for the presynaptogenic activity of Nrxns. Intriguingly, Nrxn1 and PTPσ require distinct sets of intracellular proteins for the assembly of specific presynaptic terminals. In addition, Nrxn1α showed robust heparan sulfate (HS)-dependent, high-affinity interactions with Ig domains of PTPσ that were regulated by the splicing status of PTPσ. Furthermore, Nrxn1α WT, but not a Nrxn1α mutant lacking HS moieties (Nrxn1α ΔHS), inhibited postsynapse-inducing activity of PTPσ at excitatory, but not inhibitory, synapses. Similarly, cis expression of Nrxn1α WT, but not Nrxn1α ΔHS, suppressed the PTPσ-mediated maintenance of excitatory postsynaptic specializations in mouse cultured hippocampal neurons. Lastly, genetics analyses using male or female Drosophila Dlar and Dnrx mutant larvae identified epistatic interactions that control synapse formation and synaptic transmission at neuromuscular junctions. Our results suggest a novel synaptogenesis model whereby different presynaptic adhesion molecules combine with distinct regulatory codes to orchestrate specific synaptic adhesion pathways.SIGNIFICANCE STATEMENT We provide evidence supporting the physical interactions of neurexins with leukocyte common-antigen related receptor tyrosine phosphatases (LAR-RPTPs). The availability of heparan sulfates and alternative splicing of LAR-RPTPs regulate the binding affinity of these interactions. A set of intracellular presynaptic proteins is involved in common for Nrxn- and LAR-RPTP-mediated presynaptic assembly. PTPσ triggers glutamatergic and GABAergic postsynaptic differentiation in an alternative splicing-dependent manner, whereas Nrxn1α induces GABAergic postsynaptic differentiation in an alternative splicing-independent manner. Strikingly, Nrxn1α inhibits the glutamatergic postsynapse-inducing activity of PTPσ, suggesting that PTPσ and Nrxn1α might control recruitment of a different pool of postsynaptic machinery. Drosophila orthologs of Nrxns and LAR-RPTPs mediate epistatic interactions in controlling synapse structure and strength at neuromuscular junctions, underscoring the physiological significance in vivo.
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Schrott R, Rajavel M, Acharya K, Huang Z, Acharya C, Hawkey A, Pippen E, Lyerly HK, Levin ED, Murphy SK. Sperm DNA methylation altered by THC and nicotine: Vulnerability of neurodevelopmental genes with bivalent chromatin. Sci Rep 2020; 10:16022. [PMID: 32994467 PMCID: PMC7525661 DOI: 10.1038/s41598-020-72783-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Accepted: 09/03/2020] [Indexed: 01/23/2023] Open
Abstract
Men consume the most nicotine and cannabis products but impacts on sperm epigenetics are poorly characterized. Evidence suggests that preconception exposure to these drugs alters offspring neurodevelopment. Epigenetics may in part facilitate heritability. We therefore compared effects of exposure to tetrahydrocannabinol (THC) and nicotine on DNA methylation in rat sperm at genes involved in neurodevelopment. Reduced representation bisulfite sequencing data from sperm of rats exposed to THC via oral gavage showed that seven neurodevelopmentally active genes were significantly differentially methylated versus controls. Pyrosequencing data revealed majority overlap in differential methylation in sperm from rats exposed to THC via injection as well as those exposed to nicotine. Neurodevelopmental genes including autism candidates are vulnerable to environmental exposures and common features may mediate this vulnerability. We discovered that autism candidate genes are significantly enriched for bivalent chromatin structure, suggesting this configuration may increase vulnerability of genes in sperm to disrupted methylation.
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Affiliation(s)
- Rose Schrott
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, Duke University Medical Center, Chesterfield Building, 701 W. Main Street, Suite 510, Durham, NC, 27701, USA.,Integrated Toxicology and Environmental Health Program, Nicholas School of the Environment, Duke University, Durham, NC, USA
| | - Maya Rajavel
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, Duke University Medical Center, Chesterfield Building, 701 W. Main Street, Suite 510, Durham, NC, 27701, USA
| | - Kelly Acharya
- Division of Reproductive Endocrinology and Infertility, Department of Obstetrics and Gynecology, Duke University Medical Center, Durham, NC, USA
| | - Zhiqing Huang
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, Duke University Medical Center, Chesterfield Building, 701 W. Main Street, Suite 510, Durham, NC, 27701, USA
| | - Chaitanya Acharya
- Division of Surgical Sciences, Department of Surgery, Center for Applied Therapeutics, Duke University Medical Center, Durham, NC, USA
| | - Andrew Hawkey
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
| | - Erica Pippen
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
| | - H Kim Lyerly
- Division of Surgical Sciences, Department of Surgery, Center for Applied Therapeutics, Duke University Medical Center, Durham, NC, USA
| | - Edward D Levin
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
| | - Susan K Murphy
- Division of Reproductive Sciences, Department of Obstetrics and Gynecology, Duke University Medical Center, Chesterfield Building, 701 W. Main Street, Suite 510, Durham, NC, 27701, USA. .,Integrated Toxicology and Environmental Health Program, Nicholas School of the Environment, Duke University, Durham, NC, USA. .,Department of Pathology, Duke University Medical Center, Durham, NC, USA.
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10
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Taylor SC, Ferri SL, Grewal M, Smernoff Z, Bucan M, Weiner JA, Abel T, Brodkin ES. The Role of Synaptic Cell Adhesion Molecules and Associated Scaffolding Proteins in Social Affiliative Behaviors. Biol Psychiatry 2020; 88:442-451. [PMID: 32305215 PMCID: PMC7442706 DOI: 10.1016/j.biopsych.2020.02.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 01/24/2020] [Accepted: 02/07/2020] [Indexed: 12/17/2022]
Abstract
Social affiliative behaviors-engagement in positive (i.e., nonaggressive) social approach and reciprocal social interactions with a conspecific-comprise a construct within the National Institute of Mental Health Research Domain Criteria Social Processes Domain. These behaviors are disrupted in multiple human neurodevelopmental and neuropsychiatric disorders, such as autism, schizophrenia, social phobia, and others. Human genetic studies have strongly implicated synaptic cell adhesion molecules (sCAMs) in several such disorders that involve marked reductions, or other dysregulations, of social affiliative behaviors. Here, we review the literature on the role of sCAMs in social affiliative behaviors. We integrate findings pertaining to synapse structure and morphology, neurotransmission, postsynaptic signaling pathways, and neural circuitry to propose a multilevel model that addresses the impact of a diverse group of sCAMs, including neurexins, neuroligins, protocadherins, immunoglobulin superfamily proteins, and leucine-rich repeat proteins, as well as their associated scaffolding proteins, including SHANKs and others, on social affiliative behaviors. This review finds that the disruption of sCAMs often manifests in changes in social affiliative behaviors, likely through alterations in synaptic maturity, pruning, and specificity, leading to excitation/inhibition imbalance in several key regions, namely the medial prefrontal cortex, basolateral amygdala, hippocampus, anterior cingulate cortex, and ventral tegmental area. Unraveling the complex network of interacting sCAMs in glutamatergic synapses will be an important strategy for elucidating the mechanisms of social affiliative behaviors and the alteration of these behaviors in many neuropsychiatric and neurodevelopmental disorders.
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Affiliation(s)
- Sara C Taylor
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Sarah L Ferri
- Iowa Neuroscience Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Mahip Grewal
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Zoe Smernoff
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania; Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Maja Bucan
- Department of Genetics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania
| | - Joshua A Weiner
- Iowa Neuroscience Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa; Department of Biology, University of Iowa, Iowa City, Iowa
| | - Ted Abel
- Iowa Neuroscience Institute, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Edward S Brodkin
- Department of Psychiatry, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania.
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11
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McAfee A, Milone J, Chapman A, Foster LJ, Pettis JS, Tarpy DR. Candidate stress biomarkers for queen failure diagnostics. BMC Genomics 2020; 21:571. [PMID: 32819278 PMCID: PMC7441638 DOI: 10.1186/s12864-020-06992-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 08/13/2020] [Indexed: 01/15/2023] Open
Abstract
Background Queen failure is a persistent problem in beekeeping operations, but in the absence of overt symptoms it is often difficult, if not impossible, to ascertain the root cause. Stressors like heat-shock, cold-shock, and sublethal pesticide exposure can reduce stored sperm viability and lead to cryptic queen failure. Previously, we suggested candidate protein markers indicating heat-shock in queens. Here, we further investigate these heat-shock markers and test new stressors to identify additional candidate protein markers. Results We found that heat-shocking queens for upwards of 1 h at 40 °C was necessary to induce significant changes in the two strongest candidate heat-shock markers, and that relative humidity significantly influenced the degree of activation. In blind heat-shock experiments, we tested the efficiency of these markers at assigning queens to their respective treatment groups and found that one marker was sufficient to correctly assign queens 75% of the time. Finally, we compared cold-shocked queens at 4 °C and pesticide-exposed queens to controls to identify candidate markers for these additional stressors, and compared relative abundances of all markers to queens designated as ‘healthy’ and ‘failing’ by beekeepers. Queens that failed in the field had higher expression of both heat-shock and pesticide protein markers, but not cold-shock markers. Conclusions This work offers some of the first steps towards developing molecular diagnostic tools to aid in determining cryptic causes of queen failure. Further work will be necessary to determine how long after the stress event a marker’s expression remains elevated, and how accurate these markers will be for field diagnoses.
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Affiliation(s)
- Alison McAfee
- Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, North Carolina, USA.
| | - Joseph Milone
- Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, North Carolina, USA
| | - Abigail Chapman
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | - Leonard J Foster
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - David R Tarpy
- Department of Entomology & Plant Pathology, North Carolina State University, Raleigh, North Carolina, USA
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12
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Wolking S, Schulz H, Nies AT, McCormack M, Schaeffeler E, Auce P, Avbersek A, Becker F, Klein KM, Krenn M, Møller RS, Nikanorova M, Weckhuysen S, Consortium E, Cavalleri GL, Delanty N, Depondt C, Johnson MR, Koeleman BPC, Kunz WS, Marson AG, Sander JW, Sills GJ, Striano P, Zara F, Zimprich F, Weber YG, Krause R, Sisodiya S, Schwab M, Sander T, Lerche H. Pharmacoresponse in genetic generalized epilepsy: a genome-wide association study. Pharmacogenomics 2020; 21:325-335. [DOI: 10.2217/pgs-2019-0179] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Aim: Pharmacoresistance is a major burden in epilepsy treatment. We aimed to identify genetic biomarkers in response to specific antiepileptic drugs (AEDs) in genetic generalized epilepsies (GGE). Materials & methods: We conducted a genome-wide association study (GWAS) of 3.3 million autosomal SNPs in 893 European subjects with GGE – responsive or nonresponsive to lamotrigine, levetiracetam and valproic acid. Results: Our GWAS of AED response revealed suggestive evidence for association at 29 genomic loci (p <10-5) but no significant association reflecting its limited power. The suggestive associations highlight candidate genes that are implicated in epileptogenesis and neurodevelopment. Conclusion: This first GWAS of AED response in GGE provides a comprehensive reference of SNP associations for hypothesis-driven candidate gene analyses in upcoming pharmacogenetic studies.
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Affiliation(s)
- Stefan Wolking
- Department of Neurology & Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
- Department of Neurosciences, CHUM Research Center, University of Montreal, Montreal, H2X 0A9, Canada
| | - Herbert Schulz
- Cologne Center for Genomics, University of Cologne, 50931 Cologne, Germany
| | - Anne T Nies
- Dr Margarete Fischer-Bosch Institute of Clinical Pharmacology, 70376 Stuttgart, Germany
- University of Tübingen, 72076 Tübingen, Germany
| | - Mark McCormack
- Molecular & Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, D02 YN77, Ireland
| | - Elke Schaeffeler
- Dr Margarete Fischer-Bosch Institute of Clinical Pharmacology, 70376 Stuttgart, Germany
- University of Tübingen, 72076 Tübingen, Germany
| | - Pauls Auce
- Walton Centre NHS Foundation Trust, Liverpool, L33 4YD, UK
| | - Andreja Avbersek
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, London & Chalfont Centre for Epilepsy, London, SL9 0RJ, UK
| | - Felicitas Becker
- Department of Neurology & Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
| | - Karl M Klein
- Epilepsy Center Frankfurt Rhine-Main, University Hospital Frankfurt, Goethe University Frankfurt, 60590 Frankfurt, Germany
| | - Martin Krenn
- Department of Neurology, Medical University of Vienna, 1090 Vienna, Austria
| | - Rikke S Møller
- Danish Epilepsy Centre – Filadelfia, 4293 Dianalund, Denmark
- Department of Regional Health Research, University of Southern Denmark, 5000 Odense, Denmark
| | | | - Sarah Weckhuysen
- Neurogenetics Group, Center for Molecular Neurology, VIB-University of Antwerp, 2650 Edegem, Belgium
- Laboratory of Neurogenetics, Institute Born-Bunge, University of Antwerp, 2650 Edegem, Belgium
- Department of Neurology, Antwerp University Hospital, 2650 Edegem, Belgium
| | | | - Gianpiero L Cavalleri
- Molecular & Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, D02 YN77, Ireland
- Division of Brain Sciences, Imperial College Faculty of Medicine, London, SW2 2AZ, UK
| | - Norman Delanty
- Molecular & Cellular Therapeutics, Royal College of Surgeons in Ireland, Dublin, D02 YN77, Ireland
- Division of Neurology, Beaumont Hospital, Dublin 9, Ireland
- The FutureNeuro Research Centre, Royal College of Surgeons in Ireland, Dublin, D02 YN77, Ireland
| | - Chantal Depondt
- Department of Neurology, Hôpital Erasme, Université Libre de Bruxelles, 1070 Brussels, Belgium
| | - Michael R Johnson
- Division of Brain Sciences, Imperial College Faculty of Medicine, London, SW2 2AZ, UK
| | - Bobby PC Koeleman
- Department of Genetics, University Medical Center Utrecht, 3584 Utrecht, The Netherlands
| | - Wolfram S Kunz
- Institute of Experimental Epileptology & Cognition Research & Department of Epileptology, University of Bonn, 53127 Bonn, Germany
| | - Anthony G Marson
- Department of Molecular & Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Josemir W Sander
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, London & Chalfont Centre for Epilepsy, London, SL9 0RJ, UK
- Stichting Epilepsie Instellingen Nederland (SEIN), 2103 Heemstede, The Netherlands
| | - Graeme J Sills
- Department of Molecular & Clinical Pharmacology, Institute of Translational Medicine, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Pasquale Striano
- Pediatric Neurology & Muscular Diseases Unit, IRCCS ‘G. Gaslini’ Institute, 16147 Genova, Italy
- Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal & Child Health, University of Genova, 16147 Genova, Italy
| | - Federico Zara
- Laboratory of Neurogenetics and Neuroscience, IRCCS ‘G. Gaslini’ Institute, 16147 Genova, Italy
| | - Fritz Zimprich
- Department of Neurology, Medical University of Vienna, 1090 Vienna, Austria
| | - Yvonne G Weber
- Department of Neurology & Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
| | - Roland Krause
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, 4362 Esch-sur-Alzette, Luxembourg
| | - Sanjay Sisodiya
- Department of Clinical & Experimental Epilepsy, UCL Queen Square Institute of Neurology, London & Chalfont Centre for Epilepsy, London, SL9 0RJ, UK
| | - Matthias Schwab
- Dr Margarete Fischer-Bosch Institute of Clinical Pharmacology, 70376 Stuttgart, Germany
- Department of Clinical Pharmacology, University Hospital Tübingen, 72076 Tübingen, Germany
- Department of Pharmacy & Biochemistry, University Tübingen, 72076 Tübingen, Germany
| | - Thomas Sander
- Cologne Center for Genomics, University of Cologne, 50931 Cologne, Germany
| | - Holger Lerche
- Department of Neurology & Epileptology, Hertie Institute for Clinical Brain Research, University of Tübingen, 72076 Tübingen, Germany
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13
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Loomis C, Stephens A, Janicot R, Baqai U, Drebushenko L, Round J. Identification of MAGUK scaffold proteins as intracellular binding partners of synaptic adhesion protein Slitrk2. Mol Cell Neurosci 2020; 103:103465. [DOI: 10.1016/j.mcn.2019.103465] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Revised: 12/22/2019] [Accepted: 12/30/2019] [Indexed: 01/10/2023] Open
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14
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ELFN2 is a postsynaptic cell adhesion molecule with essential roles in controlling group III mGluRs in the brain and neuropsychiatric behavior. Mol Psychiatry 2019; 24:1902-1919. [PMID: 31485013 PMCID: PMC6874751 DOI: 10.1038/s41380-019-0512-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 07/17/2019] [Accepted: 07/26/2019] [Indexed: 12/17/2022]
Abstract
The functional characterization of the GPCR interactome has predominantly focused on intracellular binding partners; however, the recent emergence of transsynaptic GPCR complexes represents an additional dimension to GPCR function that has previously been unaccounted for in drug discovery. Here, we characterize ELFN2 as a novel postsynaptic adhesion molecule with a distinct expression pattern throughout the brain and a selective binding with group III metabotropic glutamate receptors (mGluRs) in trans. Using a transcellular GPCR signaling platform, we report that ELFN2 critically alters group III mGluR secondary messenger signaling by directly altering G protein coupling kinetics and efficacy. Loss of ELFN2 in mice results in the selective downregulation of group III mGluRs and dysregulated glutamatergic synaptic transmission. Elfn2 knockout (Elfn2 KO) mice also feature a range of neuropsychiatric manifestations including seizure susceptibility, hyperactivity, and anxiety/compulsivity, which can be rescued by pharmacological augmentation of group III mGluRs. Thus, we conclude that extracellular transsynaptic scaffolding by ELFN2 in the brain is a cardinal organizational feature of group III mGluRs essential for their signaling properties and brain function.
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15
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Soto F, Tien NW, Goel A, Zhao L, Ruzycki PA, Kerschensteiner D. AMIGO2 Scales Dendrite Arbors in the Retina. Cell Rep 2019; 29:1568-1578.e4. [PMID: 31693896 PMCID: PMC6871773 DOI: 10.1016/j.celrep.2019.09.085] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 08/21/2019] [Accepted: 09/27/2019] [Indexed: 12/24/2022] Open
Abstract
The size of dendrite arbors shapes their function and differs vastly between neuron types. The signals that control dendritic arbor size remain obscure. Here, we find that in the retina, starburst amacrine cells (SACs) and rod bipolar cells (RBCs) express the homophilic cell-surface protein AMIGO2. In Amigo2 knockout (KO) mice, SAC and RBC dendrites expand while arbors of other retinal neurons remain stable. SAC dendrites are divided into a central input region and a peripheral output region that provides asymmetric inhibition to direction-selective ganglion cells (DSGCs). Input and output compartments scale precisely with increased arbor size in Amigo2 KO mice, and SAC dendrites maintain asymmetric connectivity with DSGCs. Increased coverage of SAC dendrites is accompanied by increased direction selectivity of DSGCs without changes to other ganglion cells. Our results identify AMIGO2 as a cell-type-specific dendritic scaling factor and link dendrite size and coverage to visual feature detection.
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Affiliation(s)
- Florentina Soto
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA.
| | - Nai-Wen Tien
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA; Graduate Program in Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Anurag Goel
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Lei Zhao
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Philip A Ruzycki
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Daniel Kerschensteiner
- John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University School of Medicine, Saint Louis, MO 63110, USA; Hope Center for Neurological Disorders, Washington University School of Medicine, Saint Louis, MO 63110, USA.
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16
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Ruisch IH, Dietrich A, Glennon JC, Buitelaar JK, Hoekstra PJ. Interplay between genome-wide implicated genetic variants and environmental factors related to childhood antisocial behavior in the UK ALSPAC cohort. Eur Arch Psychiatry Clin Neurosci 2019; 269:741-752. [PMID: 30569215 PMCID: PMC6689282 DOI: 10.1007/s00406-018-0964-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2018] [Accepted: 12/06/2018] [Indexed: 12/12/2022]
Abstract
We investigated gene-environment (G × E) interactions related to childhood antisocial behavior between polymorphisms implicated by recent genome-wide association studies (GWASs) and two key environmental adversities (maltreatment and smoking during pregnancy) in a large population cohort (ALSPAC). We also studied the MAOA candidate gene and addressed comorbid attention-deficit/hyperactivity disorder (ADHD). ALSPAC is a large, prospective, ethnically homogeneous British cohort. Our outcome consisted of mother-rated conduct disorder symptom scores at age 7;9 years. G × E interactions were tested in a sex-stratified way (α = 0.0031) for four GWAS-implicated variants (for males, rs4714329 and rs9471290; for females, rs2764450 and rs11215217), and a length polymorphism near the MAOA-promoter region. We found that males with rs4714329-GG (P = 0.0015) and rs9471290-AA (P = 0.0001) genotypes were significantly more susceptible to effects of smoking during pregnancy in relation to childhood antisocial behavior. Females with the rs11215217-TC genotype (P = 0.0018) were significantly less susceptible to effects of maltreatment, whereas females with the MAOA-HL genotype (P = 0.0002) were more susceptible to maltreatment effects related to antisocial behavior. After adjustment for comorbid ADHD symptomatology, aforementioned G × E's remained significant, except for rs11215217 × maltreatment, which retained only nominal significance. Genetic variants implicated by recent GWASs of antisocial behavior moderated associations of smoking during pregnancy and maltreatment with childhood antisocial behavior in the general population. While we also found a G × E interaction between the candidate gene MAOA and maltreatment, we were mostly unable to replicate the previous results regarding MAOA-G × E's. Future studies should, in addition to genome-wide implicated variants, consider polygenic and/or multimarker analyses and take into account potential sex stratification.
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Affiliation(s)
- I. Hyun Ruisch
- Department of Child and Adolescent Psychiatry, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ Groningen, The Netherlands
| | - Andrea Dietrich
- Department of Child and Adolescent Psychiatry, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ Groningen, The Netherlands
| | - Jeffrey C. Glennon
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA Nijmegen, The Netherlands
| | - Jan K. Buitelaar
- Department of Cognitive Neuroscience, Donders Institute for Brain, Cognition and Behaviour, Radboud University Medical Center, Geert Grooteplein Zuid 10, 6525GA Nijmegen, The Netherlands
- Karakter Child and Adolescent Psychiatry University Centre, Reinier Postlaan 12, 6525GC Nijmegen, The Netherlands
| | - Pieter J. Hoekstra
- Department of Child and Adolescent Psychiatry, University of Groningen, University Medical Center Groningen, Hanzeplein 1, 9713GZ Groningen, The Netherlands
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17
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Kim B. Evolutionarily conserved and divergent functions for cell adhesion molecules in neural circuit assembly. J Comp Neurol 2019; 527:2061-2068. [PMID: 30779135 DOI: 10.1002/cne.24666] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Revised: 02/11/2019] [Accepted: 02/11/2019] [Indexed: 12/17/2022]
Abstract
The developing nervous system generates remarkably precise synaptic connections between neurons and their postsynaptic target cells. Numerous neural cell adhesion proteins have been identified to mediate cell recognition between synaptic partners in several model organisms. Here, I review the role of protein interactions of cell adhesion molecules in neural circuit assembly and address how these interactions are utilized to form different neural circuitries in different species. The emerging evidence suggests that the extracellular trans-interactions of cell adhesion proteins for neural wiring are evolutionarily conserved across taxa, but they are often used in different steps of circuit assembly. I also highlight how these conserved protein interactions work together as a group to specify neural connectivity.
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Affiliation(s)
- Byunghyuk Kim
- Department of Life Science, Dongguk University Seoul, Goyang, Republic of Korea
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18
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Homozygous frameshift variant in NTNG2, encoding a synaptic cell adhesion molecule, in individuals with developmental delay, hypotonia, and autistic features. Neurogenetics 2019; 20:209-213. [DOI: 10.1007/s10048-019-00583-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Accepted: 07/21/2019] [Indexed: 12/24/2022]
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19
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Liu H. Synaptic organizers: synaptic adhesion-like molecules (SALMs). Curr Opin Struct Biol 2019; 54:59-67. [PMID: 30743183 DOI: 10.1016/j.sbi.2019.01.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 11/24/2018] [Accepted: 01/06/2019] [Indexed: 12/18/2022]
Abstract
Synaptic adhesion-like molecules (SALMs), also known as leucine-rich repeat and fibronectin III domain-containing proteins (LRFNs), are a family of synaptic adhesion molecules that consist of five members. SALMs exhibit functions in regulating neurite outgrowth and branching, synapse formation, and synapse maturation. Recent clinical studies have shown an association of SALMs with diverse neurological disorders. In this review article, we summarize structural mechanisms of the interaction of SALMs with leukocyte common antigen (LAR) family receptor tyrosine phosphatases (LAR-RPTPs) for synaptic activity, based on recent advances in the structural biology of SALMs.
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Affiliation(s)
- Heli Liu
- State Key Laboratory of Natural and Biomimetic Drugs, 38 Xueyuan Road, Haidian District, Beijing 100191, China; Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University Health Science Center, 38 Xueyuan Road, Haidian District, Beijing 100191, China.
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20
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Karki S, Paudel P, Sele C, Shkumatov AV, Kajander T. The structure of SALM5 suggests a dimeric assembly for the presynaptic RPTP ligand recognition. Protein Eng Des Sel 2019; 31:147-157. [PMID: 29897575 DOI: 10.1093/protein/gzy012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Accepted: 05/15/2018] [Indexed: 12/28/2022] Open
Abstract
Synaptic adhesion molecules play a crucial role in the regulation of synapse development and maintenance. Recently, several families of leucine-rich repeat (LRR) domain-containing neuronal adhesion molecules have been characterised, including netrin-G ligands, LRRTMs and the synaptic adhesion-like molecule (SALM) family proteins. Most of these are expressed at the excitatory glutamatergic synapses, and dysfunctions of these genes are genetically linked with cognitive disorders, such as autism spectrum disorders and schizophrenia. The SALM family proteins SALM3 and SALM5, similar to SLITRKs, have been shown to bind to the presynaptic receptor protein tyrosine phosphatase (RPTP) family ligands. Here, we present the 3.1 Å crystal structure of the SALM5 LRR-Ig-domain construct and biophysical studies that verify the crystallographic results. We show that SALM1, SALM3 and SALM5 form similar dimeric structures, in which the LRR domains form the dimer interface. Both SALM3 and SALM5 bind to RPTP immunoglobulin domains with micromolar affinity. SALM3 shows a clear preference for the RPTP ligands with the meB splice insert. Our structural studies and sequence conservation analysis suggests a ligand-binding site and mechanism for RPTP binding via the dimeric LRR domain region.
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Affiliation(s)
- Sudeep Karki
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Prodeep Paudel
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Celeste Sele
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
| | - Alexander V Shkumatov
- Structural Biology Brussels, Vrije Universiteit Brussel, Brussels 1050, Belgium.,VIB-VUB Center for Structural Biology, Brussels 1050, Belgium
| | - Tommi Kajander
- Institute of Biotechnology, University of Helsinki, Helsinki 00014, Finland
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21
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Favuzzi E, Rico B. Molecular diversity underlying cortical excitatory and inhibitory synapse development. Curr Opin Neurobiol 2018; 53:8-15. [PMID: 29704699 DOI: 10.1016/j.conb.2018.03.011] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 03/27/2018] [Accepted: 03/28/2018] [Indexed: 12/11/2022]
Abstract
The complexity and precision of cortical circuitries is achieved during development due to the exquisite diversity of synapse types that is generated in a highly regulated manner. Here, we review the recent increase in our understanding of how synapse type-specific molecules differentially regulate the development of excitatory and inhibitory synapses. Moreover, several synapse subtype-specific molecules have been shown to control the targeting, formation or maturation of particular subtypes of excitatory synapses. Because inhibitory neurons are extremely diverse, a similar molecular diversity is likely to underlie the development of different inhibitory synapses making it a promising topic for future investigation in the field of the synapse development.
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Affiliation(s)
- Emilia Favuzzi
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, United Kingdom; MRC Centre for Neurodevelopmental Disorders, King's College London, London SE1 1UL, United Kingdom
| | - Beatriz Rico
- Centre for Developmental Neurobiology, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London SE1 1UL, United Kingdom; MRC Centre for Neurodevelopmental Disorders, King's College London, London SE1 1UL, United Kingdom.
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22
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Abstract
Synapse formation is mediated by a surprisingly large number and wide variety of genes encoding many different protein classes. One of the families increasingly implicated in synapse wiring is the immunoglobulin superfamily (IgSF). IgSF molecules are by definition any protein containing at least one Ig-like domain, making this family one of the most common protein classes encoded by the genome. Here, we review the emerging roles for IgSF molecules in synapse formation specifically in the vertebrate brain, focusing on examples from three classes of IgSF members: ( a) cell adhesion molecules, ( b) signaling molecules, and ( c) immune molecules expressed in the brain. The critical roles for IgSF members in regulating synapse formation may explain their extensive involvement in neuropsychiatric and neurodevelopmental disorders. Solving the IgSF code for synapse formation may reveal multiple new targets for rescuing IgSF-mediated deficits in synapse formation and, eventually, new treatments for psychiatric disorders caused by altered IgSF-induced synapse wiring.
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Affiliation(s)
- Scott Cameron
- Center for Neuroscience, University of California, Davis, California 95618, USA; ,
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O'Brien HE, Hannon E, Hill MJ, Toste CC, Robertson MJ, Morgan JE, McLaughlin G, Lewis CM, Schalkwyk LC, Hall LS, Pardiñas AF, Owen MJ, O'Donovan MC, Mill J, Bray NJ. Expression quantitative trait loci in the developing human brain and their enrichment in neuropsychiatric disorders. Genome Biol 2018; 19:194. [PMID: 30419947 PMCID: PMC6231252 DOI: 10.1186/s13059-018-1567-1] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 10/18/2018] [Indexed: 01/03/2023] Open
Abstract
BACKGROUND Genetic influences on gene expression in the human fetal brain plausibly impact upon a variety of postnatal brain-related traits, including susceptibility to neuropsychiatric disorders. However, to date, there have been no studies that have mapped genome-wide expression quantitative trait loci (eQTL) specifically in the human prenatal brain. RESULTS We performed deep RNA sequencing and genome-wide genotyping on a unique collection of 120 human brains from the second trimester of gestation to provide the first eQTL dataset derived exclusively from the human fetal brain. We identify high confidence cis-acting eQTL at the individual transcript as well as whole gene level, including many mapping to a common inversion polymorphism on chromosome 17q21. Fetal brain eQTL are enriched among risk variants for postnatal conditions including attention deficit hyperactivity disorder, schizophrenia, and bipolar disorder. We further identify changes in gene expression within the prenatal brain that potentially mediate risk for neuropsychiatric traits, including increased expression of C4A in association with genetic risk for schizophrenia, increased expression of LRRC57 in association with genetic risk for bipolar disorder, and altered expression of multiple genes within the chromosome 17q21 inversion in association with variants influencing the personality trait of neuroticism. CONCLUSIONS We have mapped eQTL operating in the human fetal brain, providing evidence that these confer risk to certain neuropsychiatric disorders, and identifying gene expression changes that potentially mediate susceptibility to these conditions.
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Affiliation(s)
- Heath E O'Brien
- MRC Centre for Neuropsychiatric Genetics & Genomics, Division of Psychological Medicine & Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Eilis Hannon
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Matthew J Hill
- MRC Centre for Neuropsychiatric Genetics & Genomics, Division of Psychological Medicine & Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Carolina C Toste
- MRC Centre for Neuropsychiatric Genetics & Genomics, Division of Psychological Medicine & Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Matthew J Robertson
- MRC Centre for Neuropsychiatric Genetics & Genomics, Division of Psychological Medicine & Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Joanne E Morgan
- MRC Centre for Neuropsychiatric Genetics & Genomics, Division of Psychological Medicine & Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Gemma McLaughlin
- Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | - Cathryn M Lewis
- Institute of Psychiatry, Psychology & Neuroscience, King's College London, London, UK
| | | | - Lynsey S Hall
- MRC Centre for Neuropsychiatric Genetics & Genomics, Division of Psychological Medicine & Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Antonio F Pardiñas
- MRC Centre for Neuropsychiatric Genetics & Genomics, Division of Psychological Medicine & Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Michael J Owen
- MRC Centre for Neuropsychiatric Genetics & Genomics, Division of Psychological Medicine & Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Michael C O'Donovan
- MRC Centre for Neuropsychiatric Genetics & Genomics, Division of Psychological Medicine & Clinical Neurosciences, Cardiff University, Cardiff, UK
| | - Jonathan Mill
- University of Exeter Medical School, University of Exeter, Exeter, UK
| | - Nicholas J Bray
- MRC Centre for Neuropsychiatric Genetics & Genomics, Division of Psychological Medicine & Clinical Neurosciences, Cardiff University, Cardiff, UK.
- MRC Centre for Neuropsychiatric Genetics & Genomics, Cardiff University School of Medicine, Hadyn Ellis Building, Maindy Road, Cardiff, CF24 4HQ, UK.
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24
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Jacobi E, von Engelhardt J. AMPA receptor complex constituents: Control of receptor assembly, membrane trafficking and subcellular localization. Mol Cell Neurosci 2018; 91:67-75. [DOI: 10.1016/j.mcn.2018.05.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 05/15/2018] [Accepted: 05/24/2018] [Indexed: 11/29/2022] Open
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25
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Um SM, Ha S, Lee H, Kim J, Kim K, Shin W, Cho YS, Roh JD, Kang J, Yoo T, Noh YW, Choi Y, Bae YC, Kim E. NGL-2 Deletion Leads to Autistic-like Behaviors Responsive to NMDAR Modulation. Cell Rep 2018; 23:3839-3851. [DOI: 10.1016/j.celrep.2018.05.087] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Revised: 04/13/2018] [Accepted: 05/25/2018] [Indexed: 01/01/2023] Open
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26
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Park D, Bae S, Yoon TH, Ko J. Molecular Mechanisms of Synaptic Specificity: Spotlight on Hippocampal and Cerebellar Synapse Organizers. Mol Cells 2018; 41:373-380. [PMID: 29665671 PMCID: PMC5974614 DOI: 10.14348/molcells.2018.0081] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2018] [Revised: 03/30/2018] [Accepted: 04/02/2018] [Indexed: 12/13/2022] Open
Abstract
Synapses and neural circuits form with exquisite specificity during brain development to allow the precise and appropriate flow of neural information. Although this property of synapses and neural circuits has been extensively investigated for more than a century, molecular mechanisms underlying this property are only recently being unveiled. Recent studies highlight several classes of cell-surface proteins as organizing hubs in building structural and functional architectures of specific synapses and neural circuits. In the present mini-review, we discuss recent findings on various synapse organizers that confer the distinct properties of specific synapse types and neural circuit architectures in mammalian brains, with a particular focus on the hippocampus and cerebellum.
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Affiliation(s)
- Dongseok Park
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988,
Korea
| | - Sungwon Bae
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988,
Korea
| | - Taek Han Yoon
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988,
Korea
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu 42988,
Korea
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27
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Stockis J, Dedobbeleer O, Lucas S. Role of GARP in the activation of latent TGF-β1. MOLECULAR BIOSYSTEMS 2018; 13:1925-1935. [PMID: 28795730 DOI: 10.1039/c7mb00251c] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
TGF-β1, 2 and 3 cytokines are involved in many cellular processes including cell proliferation, differentiation, migration and survival. Whereas TGF-β2 and 3 play important roles in embryonic development, TGF-β1 is mostly implicated in controlling immune responses after birth. The production of TGF-β1 is a tightly regulated process, occurring mostly at a post-translational level. Virtually all cells produce the latent, inactive form of TGF-β1. In latent TGF-β1, the mature TGF-β1 dimer is non-covalently associated to the Latency Associated Peptide, or LAP, which prevents binding to the TGF-β1 receptor. Activation of the cytokine implies release of mature TGF-β1 from LAP. Only a few cell types activate latent TGF-β1, via mechanisms that are cell type specific. Proteins such as integrins, proteases and thrombospondin-1 activate TGF-β1 in epithelial cells, fibroblasts and dendritic cells. More recently, the protein GARP was shown to be involved in TGF-β1 activation by regulatory T cells (Treg), a subset of CD4+ T lymphocytes specialized in suppression of immune responses. GARP is a transmembrane protein that binds latent-TGF-β1 and tethers it on the Treg surface. The role of GARP was studied mostly in Tregs, and this was recently reviewed in L. Sun, H. Jin and H. Li, Oncotarget, 2016, 7, 42826-42836. However, GARP is also expressed in non-immune cells. This review focuses on the roles of GARP in latent TGF-β1 activation by immune and non-immune cells.
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Affiliation(s)
- Julie Stockis
- de Duve Institute, Université catholique de Louvain, Brussels, Belgium.
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28
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Deletion of LRRTM1 and LRRTM2 in adult mice impairs basal AMPA receptor transmission and LTP in hippocampal CA1 pyramidal neurons. Proc Natl Acad Sci U S A 2018; 115:E5382-E5389. [PMID: 29784826 DOI: 10.1073/pnas.1803280115] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Leucine-rich repeat transmembrane (LRRTM) proteins are synaptic cell adhesion molecules that influence synapse formation and function. They are genetically associated with neuropsychiatric disorders, and via their synaptic actions likely regulate the establishment and function of neural circuits in the mammalian brain. Here, we take advantage of the generation of a LRRTM1 and LRRTM2 double conditional knockout mouse (LRRTM1,2 cKO) to examine the role of LRRTM1,2 at mature excitatory synapses in hippocampal CA1 pyramidal neurons. Genetic deletion of LRRTM1,2 in vivo in CA1 neurons using Cre recombinase-expressing lentiviruses dramatically impaired long-term potentiation (LTP), an impairment that was rescued by simultaneous expression of LRRTM2, but not LRRTM4. Mutation or deletion of the intracellular tail of LRRTM2 did not affect its ability to rescue LTP, while point mutations designed to impair its binding to presynaptic neurexins prevented rescue of LTP. In contrast to previous work using shRNA-mediated knockdown of LRRTM1,2, KO of these proteins at mature synapses also caused a decrease in AMPA receptor-mediated, but not NMDA receptor-mediated, synaptic transmission and had no detectable effect on presynaptic function. Imaging of recombinant photoactivatable AMPA receptor subunit GluA1 in the dendritic spines of cultured neurons revealed that it was less stable in the absence of LRRTM1,2. These results illustrate the advantages of conditional genetic deletion experiments for elucidating the function of endogenous synaptic proteins and suggest that LRRTM1,2 proteins help stabilize synaptic AMPA receptors at mature spines during basal synaptic transmission and LTP.
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29
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Kawamura Y, Suga A, Fujimaki T, Yoshitake K, Tsunoda K, Murakami A, Iwata T. LRRTM4-C538Y novel gene mutation is associated with hereditary macular degeneration with novel dysfunction of ON-type bipolar cells. J Hum Genet 2018; 63:893-900. [PMID: 29760528 DOI: 10.1038/s10038-018-0465-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 03/26/2018] [Accepted: 04/14/2018] [Indexed: 11/09/2022]
Abstract
The macula is a unique structure in higher primates, where cone and rod photoreceptors show highest density in the fovea and the surrounding area, respectively. The hereditary macular dystrophies represent a heterozygous group of rare disorders characterized by central visual loss and atrophy of the macula and surrounding retina. Here we report an atypical absence of ON-type bipolar cell response in a Japanese patient with autosomal dominant macular dystrophy (adMD). To identify a causal genetic mutation for the adMD, we performed whole-exome sequencing (WES) on four affected and four-non affected members of the family for three generations, and identified a novel p.C538Y mutation in a post-synaptic gene, LRRTM4. WES analysis revealed seven rare genetic variations in patients. We further referred to our in-house WES data from 1360 families with inherited retinal diseases, and found that only p.C538Y mutation in LRRTM4 was associated with adMD-affected patients. Combinatorial filtration using public database of single-nucleotide polymorphism frequency and genotype-phenotype annotated database identified novel mutation in atypical adMD.
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Affiliation(s)
- Yuichi Kawamura
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization, Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan.,Department of Ophthalmology, Juntendo University Graduate School of Medicine, 2-1-1, Hongou, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Akiko Suga
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization, Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan
| | - Takuro Fujimaki
- Department of Ophthalmology, Juntendo University Graduate School of Medicine, 2-1-1, Hongou, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Kazutoshi Yoshitake
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization, Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan
| | - Kazushige Tsunoda
- Division of Vision Research, National Institute of Sensory Organs, National Hospital Organization, Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan
| | - Akira Murakami
- Department of Ophthalmology, Juntendo University Graduate School of Medicine, 2-1-1, Hongou, Bunkyo-ku, Tokyo, 113-8421, Japan
| | - Takeshi Iwata
- Division of Molecular and Cellular Biology, National Institute of Sensory Organs, National Hospital Organization, Tokyo Medical Center, 2-5-1, Higashigaoka, Meguro-ku, Tokyo, 152-8902, Japan.
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30
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Synaptic adhesion protein ELFN1 is a selective allosteric modulator of group III metabotropic glutamate receptors in trans. Proc Natl Acad Sci U S A 2018; 115:5022-5027. [PMID: 29686062 DOI: 10.1073/pnas.1722498115] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Functional characterization of the GPCR interactome has been focused predominantly on intracellular interactions, yet GPCRs are increasingly found in complex with extracellular proteins. Extracellular leucine-rich repeat fibronectin type III domain containing 1 (ELFN1) was recently reported to physically anchor mGluR6 and mGluR7 across retinal and hippocampal synapses, respectively; however, the consequence of transsynaptic interactions on properties and pharmacology of these receptors are unknown. In the current study, we explore the effects of ELFN1 on mGluR signaling and pharmacology. First, we established the binding specificity of ELFN1 and found it to be recruited selectively to all group III mGluRs (mGluR4, mGluR6, mGluR7, and mGluR8), but not other mGluR species. Using site-directed mutagenesis we mapped binding determinants of this interaction to two distinct sites on the ELFN1 ectodomain. To evaluate functional aspects of the interaction, we developed a transcellular signaling assay in reconstituted HEK293 cells which monitors changes in mGluR activity in one cell following its exposure to separate ELFN1-containing cells. Using this platform, we found that ELFN1 acts as an allosteric modulator of class III mGluR activity in suppressing cAMP accumulation: altering both agonist-induced and constitutive receptor activity. Using bioluminescence resonance energy transfer-based real-time kinetic assays, we established that ELFN1 alters the ability of mGluRs to activate G proteins. Our findings demonstrate that core properties of class III mGluRs can be altered via extracellular interactions with ELFN1 which serves as a transsynaptic allosteric modulator for these receptors. Furthermore, our unique assay platform opens avenues for exploring transcellular/transsynaptic pharmacology of other GPCR transcomplexes.
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31
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Leucine-rich repeat-containing synaptic adhesion molecules as organizers of synaptic specificity and diversity. Exp Mol Med 2018; 50:1-9. [PMID: 29628503 PMCID: PMC5938020 DOI: 10.1038/s12276-017-0023-8] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 12/06/2017] [Indexed: 12/14/2022] Open
Abstract
The brain harbors billions of neurons that form distinct neural circuits with exquisite specificity. Specific patterns of connectivity between distinct neuronal cell types permit the transfer and computation of information. The molecular correlates that give rise to synaptic specificity are incompletely understood. Recent studies indicate that cell-surface molecules are important determinants of cell type identity and suggest that these are essential players in the specification of synaptic connectivity. Leucine-rich repeat (LRR)-containing adhesion molecules in particular have emerged as key organizers of excitatory and inhibitory synapses. Here, we discuss emerging evidence that LRR proteins regulate the assembly of specific connectivity patterns across neural circuits, and contribute to the diverse structural and functional properties of synapses, two key features that are critical for the proper formation and function of neural circuits. Further analysis of synaptic proteins will provide insights into the functioning of neural circuits and associated brain disorders. The brain houses numerous highly specialized neuron types, which transfer and process information via a complex network of synaptic connections. Every neuron develops its own distinctive synapses with specific functions, but exactly how this is achieved is not clear. Joris de Wit and Anna Schroeder at the VIB Center for Brain and Disease Research in Leuven, Belgium, reviewed recent research into the leucine-rich repeat-containing (LRR) proteins, which are thought to be major organizers of synaptic connectivity and key regulators of healthy neural circuit development. Further investigations into the functionality of LRR proteins in the brain will not only improve understanding of neural circuitry but also provide insights into synaptic impairments in brain disorders like schizophrenia.
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32
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Ribeiro LF, Verpoort B, de Wit J. Trafficking mechanisms of synaptogenic cell adhesion molecules. Mol Cell Neurosci 2018; 91:34-47. [PMID: 29631018 DOI: 10.1016/j.mcn.2018.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 04/03/2018] [Accepted: 04/04/2018] [Indexed: 01/01/2023] Open
Abstract
Nearly every aspect of neuronal function, from wiring to information processing, critically depends on the highly polarized architecture of neurons. Establishing and maintaining the distinct molecular composition of axonal and dendritic compartments requires precise control over the trafficking of the proteins that make up these cellular domains. Synaptic cell adhesion molecules (CAMs), membrane proteins with a critical role in the formation, differentiation and plasticity of synapses, require targeting to the correct pre- or postsynaptic compartment for proper functioning of neural circuits. However, the mechanisms that control the polarized trafficking, synaptic targeting, and synaptic abundance of CAMs are poorly understood. Here, we summarize current knowledge about the sequential trafficking events along the secretory pathway that control the polarized surface distribution of synaptic CAMs, and discuss how their synaptic targeting and abundance is additionally influenced by post-secretory determinants. The identification of trafficking-impairing mutations in CAMs associated with various neurodevelopmental disorders underscores the importance of correct protein trafficking for normal brain function.
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Affiliation(s)
- Luís F Ribeiro
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Herestraat 49, 3000 Leuven, Belgium
| | - Ben Verpoort
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Herestraat 49, 3000 Leuven, Belgium
| | - Joris de Wit
- VIB Center for Brain & Disease Research, Herestraat 49, 3000 Leuven, Belgium; KU Leuven, Department of Neurosciences, Herestraat 49, 3000 Leuven, Belgium.
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33
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Soto F, Zhao L, Kerschensteiner D. Synapse maintenance and restoration in the retina by NGL2. eLife 2018; 7:30388. [PMID: 29553369 PMCID: PMC5882244 DOI: 10.7554/elife.30388] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2017] [Accepted: 03/18/2018] [Indexed: 11/13/2022] Open
Abstract
Synaptic cell adhesion molecules (CAMs) promote synapse formation in the developing nervous system. To what extent they maintain and can restore connections in the mature nervous system is unknown. Furthermore, how synaptic CAMs affect the growth of synapse-bearing neurites is unclear. Here, we use adeno-associated viruses (AAVs) to delete, re-, and overexpress the synaptic CAM NGL2 in individual retinal horizontal cells. When we removed NGL2 from horizontal cells, their axons overgrew and formed fewer synapses, irrespective of whether Ngl2 was deleted during development or in mature circuits. When we re-expressed NGL2 in knockout mice, horizontal cell axon territories and synapse numbers were restored, even if AAVs were injected after phenotypes had developed. Finally, overexpression of NGL2 in wild-type horizontal cells elevated synapse numbers above normal levels. Thus, NGL2 promotes the formation, maintenance, and restoration of synapses in the developing and mature retina, and restricts axon growth throughout life.
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Affiliation(s)
- Florentina Soto
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, United States
| | - Lei Zhao
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, United States
| | - Daniel Kerschensteiner
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, Saint Louis, United States.,Department of Neuroscience, Washington University School of Medicine, Saint Louis, United States.,Department of Biomedical Engineering, Washington University School of Medicine, Saint Louis, United States.,Hope Center for Neurological Disorders, Washington University School of Medicine, Saint Louis, United States
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34
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Cicvaric A, Yang J, Bulat T, Zambon A, Dominguez-Rodriguez M, Kühn R, Sadowicz MG, Siwert A, Egea J, Pollak DD, Moeslinger T, Monje FJ. Enhanced synaptic plasticity and spatial memory in female but not male FLRT2-haplodeficient mice. Sci Rep 2018; 8:3703. [PMID: 29487336 PMCID: PMC5829229 DOI: 10.1038/s41598-018-22030-4] [Citation(s) in RCA: 14] [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: 08/30/2017] [Accepted: 02/14/2018] [Indexed: 12/30/2022] Open
Abstract
The Fibronectin Leucine-Rich Transmembrane protein 2 (FLRT2) has been implicated in several hormone -and sex-dependent physiological and pathological processes (including chondrogenesis, menarche and breast cancer); is known to regulate developmental synapses formation, and is expressed in the hippocampus, a brain structure central for learning and memory. However, the role of FLRT2 in the adult hippocampus and its relevance in sex-dependent brain functions remains unknown. We here used adult single-allele FLRT2 knockout (FLRT2+/-) mice and behavioral, electrophysiological, and molecular/biological assays to examine the effects of FLRT2 haplodeficiency on synaptic plasticity and hippocampus-dependent learning and memory. Female and male FLRT2+/- mice presented morphological features (including body masses, brain shapes/weights, and brain macroscopic cytoarchitectonic organization), indistinguishable from their wild type counterparts. However, in vivo examinations unveiled enhanced hippocampus-dependent spatial memory recall in female FLRT2+/- animals, concomitant with augmented hippocampal synaptic plasticity and decreased levels of the glutamate transporter EAAT2 and beta estrogen receptors. In contrast, male FLRT2+/- animals exhibited deficient memory recall and decreased alpha estrogen receptor levels. These observations propose that FLRT2 can regulate memory functions in the adulthood in a sex-specific manner and might thus contribute to further research on the mechanisms linking sexual dimorphism and cognition.
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Affiliation(s)
- Ana Cicvaric
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Jiaye Yang
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Tanja Bulat
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Alice Zambon
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Manuel Dominguez-Rodriguez
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Rebekka Kühn
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Michael G Sadowicz
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Anjana Siwert
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Joaquim Egea
- Molecular and Developmental Neurobiology Research Group, Universitat de Lleida - IRBLleida, Office 1.13, Lab. 1.06. Avda. Rovira Roure, 80, 25198, Lleida, Spain
| | - Daniela D Pollak
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Thomas Moeslinger
- Institute for Physiology, Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria
| | - Francisco J Monje
- Department of Neurophysiology and Neuropharmacology, Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090, Vienna, Austria.
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35
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Monavarfeshani A, Stanton G, Van Name J, Su K, Mills WA, Swilling K, Kerr A, Huebschman NA, Su J, Fox MA. LRRTM1 underlies synaptic convergence in visual thalamus. eLife 2018; 7:e33498. [PMID: 29424692 PMCID: PMC5826289 DOI: 10.7554/elife.33498] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Accepted: 02/08/2018] [Indexed: 11/13/2022] Open
Abstract
It has long been thought that the mammalian visual system is organized into parallel pathways, with incoming visual signals being parsed in the retina based on feature (e.g. color, contrast and motion) and then transmitted to the brain in unmixed, feature-specific channels. To faithfully convey feature-specific information from retina to cortex, thalamic relay cells must receive inputs from only a small number of functionally similar retinal ganglion cells. However, recent studies challenged this by revealing substantial levels of retinal convergence onto relay cells. Here, we sought to identify mechanisms responsible for the assembly of such convergence. Using an unbiased transcriptomics approach and targeted mutant mice, we discovered a critical role for the synaptic adhesion molecule Leucine Rich Repeat Transmembrane Neuronal 1 (LRRTM1) in the emergence of retinothalamic convergence. Importantly, LRRTM1 mutant mice display impairment in visual behaviors, suggesting a functional role of retinothalamic convergence in vision.
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Affiliation(s)
- Aboozar Monavarfeshani
- Developmental and Translational Neurobiology CenterVirginia Tech Carilion Research InstituteRoanokeUnited States
- Department of Biological SciencesVirginia TechBlacksburgUnited States
| | - Gail Stanton
- Developmental and Translational Neurobiology CenterVirginia Tech Carilion Research InstituteRoanokeUnited States
- Virginia Tech Carilion School of MedicineRoanokeUnited States
| | - Jonathan Van Name
- Developmental and Translational Neurobiology CenterVirginia Tech Carilion Research InstituteRoanokeUnited States
| | - Kaiwen Su
- Developmental and Translational Neurobiology CenterVirginia Tech Carilion Research InstituteRoanokeUnited States
| | - William A Mills
- Developmental and Translational Neurobiology CenterVirginia Tech Carilion Research InstituteRoanokeUnited States
- Translational Biology, Medicine, and Health Graduate ProgramVirginia TechBlacksburgUnited States
| | - Kenya Swilling
- Developmental and Translational Neurobiology CenterVirginia Tech Carilion Research InstituteRoanokeUnited States
| | - Alicia Kerr
- Developmental and Translational Neurobiology CenterVirginia Tech Carilion Research InstituteRoanokeUnited States
- Translational Biology, Medicine, and Health Graduate ProgramVirginia TechBlacksburgUnited States
| | | | - Jianmin Su
- Developmental and Translational Neurobiology CenterVirginia Tech Carilion Research InstituteRoanokeUnited States
| | - Michael A Fox
- Developmental and Translational Neurobiology CenterVirginia Tech Carilion Research InstituteRoanokeUnited States
- Department of Biological SciencesVirginia TechBlacksburgUnited States
- Virginia Tech Carilion School of MedicineRoanokeUnited States
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36
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Ledda F, Paratcha G. Mechanisms regulating dendritic arbor patterning. Cell Mol Life Sci 2017; 74:4511-4537. [PMID: 28735442 PMCID: PMC11107629 DOI: 10.1007/s00018-017-2588-8] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2016] [Revised: 06/14/2017] [Accepted: 07/06/2017] [Indexed: 12/17/2022]
Abstract
The nervous system is populated by diverse types of neurons, each of which has dendritic trees with strikingly different morphologies. These neuron-specific morphologies determine how dendritic trees integrate thousands of synaptic inputs to generate different firing properties. To ensure proper neuronal function and connectivity, it is necessary that dendrite patterns are precisely controlled and coordinated with synaptic activity. Here, we summarize the molecular and cellular mechanisms that regulate the formation of cell type-specific dendrite patterns during development. We focus on different aspects of vertebrate dendrite patterning that are particularly important in determining the neuronal function; such as the shape, branching, orientation and size of the arbors as well as the development of dendritic spine protrusions that receive excitatory inputs and compartmentalize postsynaptic responses. Additionally, we briefly comment on the implications of aberrant dendritic morphology for nervous system disease.
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Affiliation(s)
- Fernanda Ledda
- Division of Molecular and Cellular Neuroscience, Institute of Cell Biology and Neuroscience (IBCN)-CONICET, School of Medicine, University of Buenos Aires (UBA), Paraguay 2155, 3rd Floor, CABA, 1121, Buenos Aires, Argentina
| | - Gustavo Paratcha
- Division of Molecular and Cellular Neuroscience, Institute of Cell Biology and Neuroscience (IBCN)-CONICET, School of Medicine, University of Buenos Aires (UBA), Paraguay 2155, 3rd Floor, CABA, 1121, Buenos Aires, Argentina.
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37
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Tanabe Y, Naito Y, Vasuta C, Lee AK, Soumounou Y, Linhoff MW, Takahashi H. IgSF21 promotes differentiation of inhibitory synapses via binding to neurexin2α. Nat Commun 2017; 8:408. [PMID: 28864826 PMCID: PMC5581337 DOI: 10.1038/s41467-017-00333-w] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Accepted: 06/21/2017] [Indexed: 11/16/2022] Open
Abstract
Coordinated development of excitatory and inhibitory synapses is essential for higher brain function, and impairment in this development is associated with neuropsychiatric disorders. In contrast to the large body of accumulated evidence regarding excitatory synapse development, little is known about synaptic adhesion and organization mechanisms underlying inhibitory synapse development. Through unbiased expression screens and proteomics, we identified immunoglobulin superfamily member 21 (IgSF21) as a neurexin2α-interacting membrane protein that selectively induces inhibitory presynaptic differentiation. IgSF21 localizes postsynaptically and recruits axonal neurexin2α in a trans-interaction manner. Deleting IgSF21 in mice impairs inhibitory presynaptic organization, especially in the hippocampal CA1 stratum radiatum, and also diminishes GABA-mediated synaptic transmission in hippocampal CA1 neurons without affecting their excitatory synapses. Finally, mice lacking IgSF21 show a sensorimotor gating deficit. These findings suggest that IgSF21 selectively regulates inhibitory presynaptic differentiation through interacting with presynaptic neurexin2α and plays a crucial role in synaptic inhibition in the brain. Molecular mechanisms regulating the development of inhibitory synapses are poorly understood. Here the authors show that IgSF21 interacts with neurexin2α to induce presynaptic differentiation of inhibitory synapses, and that mice lacking IgSF21 exhibit deficits in inhibitory synaptic transmission.
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Affiliation(s)
- Yuko Tanabe
- Synapse Development and Plasticity Research Unit, Institut de RecherchesCliniques de Montréal, Montreal, QC, Canada, H2W 1R7
| | - Yusuke Naito
- Synapse Development and Plasticity Research Unit, Institut de RecherchesCliniques de Montréal, Montreal, QC, Canada, H2W 1R7.,Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada, H3A 2B2
| | - Cristina Vasuta
- Synapse Development and Plasticity Research Unit, Institut de RecherchesCliniques de Montréal, Montreal, QC, Canada, H2W 1R7
| | - Alfred Kihoon Lee
- Synapse Development and Plasticity Research Unit, Institut de RecherchesCliniques de Montréal, Montreal, QC, Canada, H2W 1R7.,Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada, H3A 2B2
| | - Youssouf Soumounou
- Synapse Development and Plasticity Research Unit, Institut de RecherchesCliniques de Montréal, Montreal, QC, Canada, H2W 1R7
| | - Michael W Linhoff
- Department of Anatomy and Neurobiology, Washington University School of Medicine, St. Louis, MO, 63110, USA.,The Brain Research Centre and Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada, V6T 2B5.,Vollum Institute, Oregon Health and Science University, Portland, OR, 97239, USA
| | - Hideto Takahashi
- Synapse Development and Plasticity Research Unit, Institut de RecherchesCliniques de Montréal, Montreal, QC, Canada, H2W 1R7. .,Integrated Program in Neuroscience, McGill University, Montreal, QC, Canada, H3A 2B2. .,Department of Medicine, Université de Montréal, Montreal, QC, Canada, H3T 1J4. .,Division of Experimental Medicine, McGill University, Montreal, QC, Canada, H3A 0G4.
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38
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Diversity in AMPA receptor complexes in the brain. Curr Opin Neurobiol 2017; 45:32-38. [DOI: 10.1016/j.conb.2017.03.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 02/28/2017] [Accepted: 03/03/2017] [Indexed: 11/23/2022]
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39
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Neural Glycosylphosphatidylinositol-Anchored Proteins in Synaptic Specification. Trends Cell Biol 2017; 27:931-945. [PMID: 28743494 DOI: 10.1016/j.tcb.2017.06.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2017] [Revised: 06/27/2017] [Accepted: 06/29/2017] [Indexed: 12/15/2022]
Abstract
Glycosylphosphatidylinositol (GPI)-anchored proteins are a specialized class of lipid-associated neuronal membrane proteins that perform diverse functions in the dynamic control of axon guidance, synaptic adhesion, cytoskeletal remodeling, and localized signal transduction, particularly at lipid raft domains. Recent studies have demonstrated that a subset of GPI-anchored proteins act as critical regulators of synapse development by modulating specific synaptic adhesion pathways via direct interactions with key synapse-organizing proteins. Additional studies have revealed that alteration of these regulatory mechanisms may underlie various brain disorders. In this review, we highlight the emerging role of GPI-anchored proteins as key synapse organizers that aid in shaping the properties of various types of synapses and circuits in mammals.
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40
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Neuillé M, Cao Y, Caplette R, Guerrero-Given D, Thomas C, Kamasawa N, Sahel JA, Hamel CP, Audo I, Picaud S, Martemyanov KA, Zeitz C. LRIT3 Differentially Affects Connectivity and Synaptic Transmission of Cones to ON- and OFF-Bipolar Cells. Invest Ophthalmol Vis Sci 2017; 58:1768-1778. [PMID: 28334377 PMCID: PMC5374884 DOI: 10.1167/iovs.16-20745] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Purpose Mutations in LRIT3 lead to complete congenital stationary night blindness (cCSNB). Using a cCSNB mouse model lacking Lrit3 (nob6), we recently have shown that LRIT3 has a role in the correct localization of TRPM1 (transient receptor potential melastatin 1) to the dendritic tips of ON-bipolar cells (BCs), contacting both rod and cone photoreceptors. Furthermore, postsynaptic clustering of other mGluR6 cascade components is selectively eliminated at the dendritic tips of cone ON-BCs. The purpose of this study was to further define the role of LRIT3 in structural and functional organization of cone synapses. Methods Exhaustive electroretinogram analysis was performed in a patient with LRIT3 mutations. Multielectrode array recordings were performed at the level of retinal ganglion cells in nob6 mice. Targeting of GluR1 and GluR5 at the dendritic tips of OFF-BCs in nob6 retinas was assessed by immunostaining and confocal microscopy. The ultrastructure of photoreceptor synapses was evaluated by electron microscopy in nob6 mice. Results The patient with LRIT3 mutations had a selective ON-BC dysfunction with relatively preserved OFF-BC responses. In nob6 mice, complete lack of ON-pathway function with robust, yet altered signaling processing in OFF-pathways was detected. Consistent with these observations, molecules essential for the OFF-BC signaling were normally targeted to the synapse. Finally, synaptic contacts made by ON-BC but not OFF-BC neurons with the cone pedicles were disorganized without ultrastructural alterations in cone terminals, horizontal cell processes, or synaptic ribbons. Conclusions These results suggest that LRIT3 is likely involved in coordination of the transsynaptic communication between cones and ON-BCs during synapse formation and function.
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Affiliation(s)
- Marion Neuillé
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France
| | - Yan Cao
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida United States
| | - Romain Caplette
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France
| | | | - Connon Thomas
- Max Planck Florida Institute for Neuroscience, Jupiter, Florida United States
| | - Naomi Kamasawa
- Max Planck Florida Institute for Neuroscience, Jupiter, Florida United States
| | - José-Alain Sahel
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France 4CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC1423, Paris, France 5Institute of Ophthalmology, University College of London, London, United Kingdom 6Fondation Ophtalmologique Adolphe de Rothschild, Paris, France 8Department of Ophthalmology, The University of Pittsburgh School of Medicine, Pittsburgh, United States
| | - Christian P Hamel
- INSERM U583, Physiopathologie et thérapie des déficits sensoriels et moteurs, Institut des Neurosciences de Montpellier, Hôpital Saint-Eloi, Montpellier, France
| | - Isabelle Audo
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France 4CHNO des Quinze-Vingts, DHU Sight Restore, INSERM-DHOS CIC1423, Paris, France 5Institute of Ophthalmology, University College of London, London, United Kingdom
| | - Serge Picaud
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France
| | - Kirill A Martemyanov
- Department of Neuroscience, The Scripps Research Institute, Jupiter, Florida United States
| | - Christina Zeitz
- Sorbonne Universités, UPMC Univ Paris 06, INSERM U968, CNRS UMR 7210, Institut de la Vision, Paris, France
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41
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Sakurai T. The role of cell adhesion molecules in brain wiring and neuropsychiatric disorders. Mol Cell Neurosci 2017; 81:4-11. [PMID: 27561442 DOI: 10.1016/j.mcn.2016.08.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 08/16/2016] [Accepted: 08/19/2016] [Indexed: 12/15/2022] Open
Abstract
Cell adhesion molecules (CAMs) in the nervous system have long been a research focus, but many mice lacking CAMs show very subtle phenotypes, giving an impression that CAMs may not be major players in constructing the nervous system. However, recent human genetic studies suggest CAM involvement in many neuropsychiatric disorders, implicating that they must have significant functions in nervous system development, namely in circuitry formation. As CAMs can provide specificity through their molecular interactions, this review summarizes possible mechanisms on how alterations of CAMs can result in neuropsychiatric disorders through circuitry modification.
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Affiliation(s)
- Takeshi Sakurai
- Medical Innovation Center, Kyoto University Graduate School of Medicine, 53 Shogoin Kawaharacho, Sakyo-ku, Kyoto, 606-8507, Japan.
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42
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Bibollet-Bahena O, Okafuji T, Hokamp K, Tear G, Mitchell KJ. A dual-strategy expression screen for candidate connectivity labels in the developing thalamus. PLoS One 2017; 12:e0177977. [PMID: 28558017 PMCID: PMC5448750 DOI: 10.1371/journal.pone.0177977] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2016] [Accepted: 05/05/2017] [Indexed: 12/13/2022] Open
Abstract
The thalamus or “inner chamber” of the brain is divided into ~30 discrete nuclei, with highly specific patterns of afferent and efferent connectivity. To identify genes that may direct these patterns of connectivity, we used two strategies. First, we used a bioinformatics pipeline to survey the predicted proteomes of nematode, fruitfly, mouse and human for extracellular proteins containing any of a list of motifs found in known guidance or connectivity molecules. Second, we performed clustering analyses on the Allen Developing Mouse Brain Atlas data to identify genes encoding surface proteins expressed with temporal profiles similar to known guidance or connectivity molecules. In both cases, we then screened the resultant genes for selective expression patterns in the developing thalamus. These approaches identified 82 candidate connectivity labels in the developing thalamus. These molecules include many members of the Ephrin, Eph-receptor, cadherin, protocadherin, semaphorin, plexin, Odz/teneurin, Neto, cerebellin, calsyntenin and Netrin-G families, as well as diverse members of the immunoglobulin (Ig) and leucine-rich receptor (LRR) superfamilies, receptor tyrosine kinases and phosphatases, a variety of growth factors and receptors, and a large number of miscellaneous membrane-associated or secreted proteins not previously implicated in axonal guidance or neuronal connectivity. The diversity of their expression patterns indicates that thalamic nuclei are highly differentiated from each other, with each one displaying a unique repertoire of these molecules, consistent with a combinatorial logic to the specification of thalamic connectivity.
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Affiliation(s)
| | - Tatsuya Okafuji
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Karsten Hokamp
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
| | - Guy Tear
- Department of Developmental Neurobiology, New Hunt’s House, Guy’s Campus, King’s College, London, United Kingdom
| | - Kevin J. Mitchell
- Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland
- Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
- * E-mail:
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43
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Roh JD, Choi SY, Cho YS, Choi TY, Park JS, Cutforth T, Chung W, Park H, Lee D, Kim MH, Lee Y, Mo S, Rhee JS, Kim H, Ko J, Choi SY, Bae YC, Shen K, Kim E, Han K. Increased Excitatory Synaptic Transmission of Dentate Granule Neurons in Mice Lacking PSD-95-Interacting Adhesion Molecule Neph2/Kirrel3 during the Early Postnatal Period. Front Mol Neurosci 2017; 10:81. [PMID: 28381988 PMCID: PMC5360738 DOI: 10.3389/fnmol.2017.00081] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2017] [Accepted: 03/08/2017] [Indexed: 11/13/2022] Open
Abstract
Copy number variants and point mutations of NEPH2 (also called KIRREL3) gene encoding an immunoglobulin (Ig) superfamily adhesion molecule have been linked to autism spectrum disorders, intellectual disability and neurocognitive delay associated with Jacobsen syndrome, but the physiological roles of Neph2 in the mammalian brain remain largely unknown. Neph2 is highly expressed in the dentate granule (DG) neurons of the hippocampus and is localized in both dendrites and axons. It was recently shown that Neph2 is required for the formation of mossy fiber filopodia, the axon terminal structure of DG neurons forming synapses with GABAergic neurons of CA3. In contrast, however, it is unknown whether Neph2 also has any roles in the postsynaptic compartments of DG neurons. We here report that, through its C-terminal PDZ domain-binding motif, Neph2 directly interacts with postsynaptic density (PSD)-95, an abundant excitatory postsynaptic scaffolding protein. Moreover, Neph2 protein is detected in the brain PSD fraction and interacts with PSD-95 in synaptosomal lysates. Functionally, loss of Neph2 in mice leads to age-specific defects in the synaptic connectivity of DG neurons. Specifically, Neph2-/- mice show significantly increased spontaneous excitatory synaptic events in DG neurons at postnatal week 2 when the endogenous Neph2 protein expression peaks, but show normal excitatory synaptic transmission at postnatal week 3. The evoked excitatory synaptic transmission and synaptic plasticity of medial perforant pathway (MPP)-DG synapses are also normal in Neph2-/- mice at postnatal week 3, further confirming the age-specific synaptic defects. Together, our results provide some evidence for the postsynaptic function of Neph2 in DG neurons during the early postnatal period, which might be implicated in neurodevelopmental and cognitive disorders caused by NEPH2 mutations.
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Affiliation(s)
- Junyeop D Roh
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST) Daejeon, South Korea
| | - Su-Yeon Choi
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS) Daejeon, South Korea
| | - Yi Sul Cho
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University Daegu, South Korea
| | - Tae-Yong Choi
- Department of Physiology, Dental Research Institute, Seoul National University School of Dentistry Seoul, South Korea
| | - Jong-Sil Park
- Department of Physiology, Dental Research Institute, Seoul National University School of Dentistry Seoul, South Korea
| | - Tyler Cutforth
- Department of Neurology, Columbia University Medical Center New York, NY, USA
| | - Woosuk Chung
- Department of Anesthesiology and Pain Medicine, College of Medicine, Chungnam National University Daejeon, South Korea
| | - Hanwool Park
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS) Daejeon, South Korea
| | - Dongsoo Lee
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS) Daejeon, South Korea
| | - Myeong-Heui Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST) Daejeon, South Korea
| | - Yeunkum Lee
- Department of Neuroscience, College of Medicine, Korea University Seoul, South Korea
| | - Seojung Mo
- Department of Anatomy, College of Medicine, Korea University Seoul, South Korea
| | - Jeong-Seop Rhee
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine Göttingen, Germany
| | - Hyun Kim
- Department of Anatomy, College of Medicine, Korea University Seoul, South Korea
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology (DGIST) Daegu, South Korea
| | - Se-Young Choi
- Department of Physiology, Dental Research Institute, Seoul National University School of Dentistry Seoul, South Korea
| | - Yong Chul Bae
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University Daegu, South Korea
| | - Kang Shen
- Department of Biology, Howard Hughes Medical Institute, Stanford University Stanford, CA, USA
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST)Daejeon, South Korea; Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS)Daejeon, South Korea
| | - Kihoon Han
- Department of Neuroscience, College of Medicine, Korea University Seoul, South Korea
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Schreiner D, Savas JN, Herzog E, Brose N, de Wit J. Synapse biology in the 'circuit-age'-paths toward molecular connectomics. Curr Opin Neurobiol 2017; 42:102-110. [PMID: 28033531 PMCID: PMC5316339 DOI: 10.1016/j.conb.2016.12.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2016] [Revised: 12/07/2016] [Accepted: 12/08/2016] [Indexed: 11/23/2022]
Abstract
The neural connectome is a critical determinant of brain function. Circuits of precisely wired neurons, and the features of transmission at the synapses connecting them, are thought to dictate information processing in the brain. While recent technological advances now allow to define the anatomical and functional neural connectome at unprecedented resolution, the elucidation of the molecular mechanisms that establish the precise patterns of connectivity and the functional characteristics of synapses has remained challenging. Here, we describe the power and limitations of genetic approaches in the analysis of mechanisms that control synaptic connectivity and function, and discuss how recent methodological developments in proteomics might be used to elucidate the molecular synaptic connectome that is at the basis of the neural connectome.
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Affiliation(s)
- Dietmar Schreiner
- Biozentrum, University of Basel, Klingelbergstraße 50-70, 4056 Basel, Switzerland; Institute of Neuroanatomy and Cell Biology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany
| | - Jeffrey N Savas
- Department of Neurology, Northwestern University, Feinberg School of Medicine, 303 East Chicago Avenue, Chicago, IL 60611, USA
| | - Etienne Herzog
- Univ. Bordeaux, IINS, UMR 5297, F-33000 Bordeaux, France; CNRS, IINS, UMR 5297, F-33000 Bordeaux, France
| | - Nils Brose
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, 37075 Göttingen, Germany
| | - Joris de Wit
- VIB Center for Brain and Disease Research, Herestraat 49, 3000 Leuven, Belgium; Department of Neurosciences, KU Leuven, Herestraat 49, 3000 Leuven, Belgium.
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45
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Dynamic Control of Synaptic Adhesion and Organizing Molecules in Synaptic Plasticity. Neural Plast 2017; 2017:6526151. [PMID: 28255461 PMCID: PMC5307005 DOI: 10.1155/2017/6526151] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2016] [Accepted: 12/13/2016] [Indexed: 12/13/2022] Open
Abstract
Synapses play a critical role in establishing and maintaining neural circuits, permitting targeted information transfer throughout the brain. A large portfolio of synaptic adhesion/organizing molecules (SAMs) exists in the mammalian brain involved in synapse development and maintenance. SAMs bind protein partners, forming trans-complexes spanning the synaptic cleft or cis-complexes attached to the same synaptic membrane. SAMs play key roles in cell adhesion and in organizing protein interaction networks; they can also provide mechanisms of recognition, generate scaffolds onto which partners can dock, and likely take part in signaling processes as well. SAMs are regulated through a portfolio of different mechanisms that affect their protein levels, precise localization, stability, and the availability of their partners at synapses. Interaction of SAMs with their partners can further be strengthened or weakened through alternative splicing, competing protein partners, ectodomain shedding, or astrocytically secreted factors. Given that numerous SAMs appear altered by synaptic activity, in vivo, these molecules may be used to dynamically scale up or scale down synaptic communication. Many SAMs, including neurexins, neuroligins, cadherins, and contactins, are now implicated in neuropsychiatric and neurodevelopmental diseases, such as autism spectrum disorder, schizophrenia, and bipolar disorder and studying their molecular mechanisms holds promise for developing novel therapeutics.
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46
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Roppongi RT, Karimi B, Siddiqui TJ. Role of LRRTMs in synapse development and plasticity. Neurosci Res 2016; 116:18-28. [PMID: 27810425 DOI: 10.1016/j.neures.2016.10.003] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 10/10/2016] [Accepted: 10/14/2016] [Indexed: 12/19/2022]
Abstract
Leucine-rich-repeat transmembrane neuronal proteins (LRRTMs) are a family of four synapse organizing proteins critical for the development and function of excitatory synapses. The genes encoding LRRTMs and their binding partners, neurexins and HSPGs, are strongly associated with multiple psychiatric disorders. Here, we review the literature covering their structural features, expression patterns in the developing and adult brains, evolutionary origins, and discovery as synaptogenic proteins. We also discuss their role in the development and plasticity of excitatory synapses as well as their disease associations.
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Affiliation(s)
- Reiko T Roppongi
- Department of Physiology and Pathophysiology, College of Medicine, University of Manitoba, Winnipeg, MB, Canada; Neuroscience Research Program, Kleysen Institute for Advanced Medicine, Health Sciences Centre, 710 William Avenue, Winnipeg R3Y 0Z3, MB, Canada
| | - Benyamin Karimi
- Department of Physiology and Pathophysiology, College of Medicine, University of Manitoba, Winnipeg, MB, Canada; Neuroscience Research Program, Kleysen Institute for Advanced Medicine, Health Sciences Centre, 710 William Avenue, Winnipeg R3Y 0Z3, MB, Canada
| | - Tabrez J Siddiqui
- Department of Physiology and Pathophysiology, College of Medicine, University of Manitoba, Winnipeg, MB, Canada; Neuroscience Research Program, Kleysen Institute for Advanced Medicine, Health Sciences Centre, 710 William Avenue, Winnipeg R3Y 0Z3, MB, Canada.
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Abstract
Repeats are ubiquitous elements of proteins and they play important roles for cellular function and during evolution. Repeats are, however, also notoriously difficult to capture computationally and large scale studies so far had difficulties in linking genetic causes, structural properties and evolutionary trajectories of protein repeats. Here we apply recently developed methods for repeat detection and analysis to a large dataset comprising over hundred metazoan genomes. We find that repeats in larger protein families experience generally very few insertions or deletions (indels) of repeat units but there is also a significant fraction of noteworthy volatile outliers with very high indel rates. Analysis of structural data indicates that repeats with an open structure and independently folding units are more volatile and more likely to be intrinsically disordered. Such disordered repeats are also significantly enriched in sites with a high functional potential such as linear motifs. Furthermore, the most volatile repeats have a high sequence similarity between their units. Since many volatile repeats also show signs of recombination, we conclude they are often shaped by concerted evolution. Intriguingly, many of these conserved yet volatile repeats are involved in host-pathogen interactions where they might foster fast but subtle adaptation in biological arms races. KEY WORDS: protein evolution, domain rearrangements, protein repeats, concerted evolution.
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Affiliation(s)
- Andreas Schüler
- Institute for Evolution and Biodiversity, Westfalian Wilhelms University, Huefferstrasse 1, Muenster, Germany
| | - Erich Bornberg-Bauer
- Institute for Evolution and Biodiversity, Westfalian Wilhelms University, Huefferstrasse 1, Muenster, Germany
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48
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Ledda F, Paratcha G. Assembly of Neuronal Connectivity by Neurotrophic Factors and Leucine-Rich Repeat Proteins. Front Cell Neurosci 2016; 10:199. [PMID: 27555809 PMCID: PMC4977320 DOI: 10.3389/fncel.2016.00199] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 07/29/2016] [Indexed: 11/13/2022] Open
Abstract
Proper function of the nervous system critically relies on sophisticated neuronal networks interconnected in a highly specific pattern. The architecture of these connections arises from sequential developmental steps such as axonal growth and guidance, dendrite development, target determination, synapse formation and plasticity. Leucine-rich repeat (LRR) transmembrane proteins have been involved in cell-type specific signaling pathways that underlie these developmental processes. The members of this superfamily of proteins execute their functions acting as trans-synaptic cell adhesion molecules involved in target specificity and synapse formation or working in cis as cell-intrinsic modulators of neurotrophic factor receptor trafficking and signaling. In this review, we will focus on novel physiological mechanisms through which LRR proteins regulate neurotrophic factor receptor signaling, highlighting the importance of these modulatory events for proper axonal extension and guidance, tissue innervation and dendrite morphogenesis. Additionally, we discuss few examples linking this set of LRR proteins to neurodevelopmental and psychiatric disorders.
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Affiliation(s)
- Fernanda Ledda
- Division of Molecular and Cellular Neuroscience, Institute of Cell Biology and Neuroscience (IBCN)-CONICET, School of Medicine-University of Buenos Aires (UBA) Buenos Aires, Argentina
| | - Gustavo Paratcha
- Division of Molecular and Cellular Neuroscience, Institute of Cell Biology and Neuroscience (IBCN)-CONICET, School of Medicine-University of Buenos Aires (UBA) Buenos Aires, Argentina
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49
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Pinto MJ, Almeida RD. Puzzling out presynaptic differentiation. J Neurochem 2016; 139:921-942. [PMID: 27315450 DOI: 10.1111/jnc.13702] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2016] [Revised: 05/27/2016] [Accepted: 06/10/2016] [Indexed: 12/24/2022]
Abstract
Proper brain function in the nervous system relies on the accurate establishment of synaptic contacts during development. Countless synapses populate the adult brain in an orderly fashion. In each synapse, a presynaptic terminal loaded with neurotransmitters-containing synaptic vesicles is perfectly aligned to an array of receptors in the postsynaptic membrane. Presynaptic differentiation, which encompasses the events underlying assembly of new presynaptic units, has seen notable advances in recent years. It is now consensual that as a growing axon encounters the receptive dendrites of its partner, presynaptic assembly will be triggered and specified by multiple postsynaptically-derived factors including soluble molecules and cell adhesion complexes. Presynaptic material that reaches these distant sites by axonal transport in the form of pre-assembled packets will be retained and clustered, ultimately giving rise to a presynaptic bouton. This review focuses on the cellular and molecular aspects of presynaptic differentiation in the central nervous system, with a particular emphasis on the identity of the instructive factors and the intracellular processes used by neuronal cells to assemble functional presynaptic terminals. We provide a detailed description of the mechanisms leading to the formation of new presynaptic terminals. In brief, soma-derived packets of pre-assembled material are trafficked to distant axonal sites. Synaptogenic factors from dendritic or glial provenance activate downstream intra-axonal mediators to trigger clustering of passing material and their correct organization into a new presynaptic bouton. This article is part of a mini review series: "Synaptic Function and Dysfunction in Brain Diseases".
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Affiliation(s)
- Maria J Pinto
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,PhD Programme in Experimental Biology and Biomedicine (PDBEB), Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Ramiro D Almeida
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,School of Allied Health Technologies, Polytechnic Institute of Oporto, Vila Nova de Gaia, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
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Choi Y, Nam J, Whitcomb DJ, Song YS, Kim D, Jeon S, Um JW, Lee SG, Woo J, Kwon SK, Li Y, Mah W, Kim HM, Ko J, Cho K, Kim E. SALM5 trans-synaptically interacts with LAR-RPTPs in a splicing-dependent manner to regulate synapse development. Sci Rep 2016; 6:26676. [PMID: 27225731 PMCID: PMC4881023 DOI: 10.1038/srep26676] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 05/04/2016] [Indexed: 11/08/2022] Open
Abstract
Synaptogenic adhesion molecules play critical roles in synapse formation. SALM5/Lrfn5, a SALM/Lrfn family adhesion molecule implicated in autism spectrum disorders (ASDs) and schizophrenia, induces presynaptic differentiation in contacting axons, but its presynaptic ligand remains unknown. We found that SALM5 interacts with the Ig domains of LAR family receptor protein tyrosine phosphatases (LAR-RPTPs; LAR, PTPδ, and PTPσ). These interactions are strongly inhibited by the splice insert B in the Ig domain region of LAR-RPTPs, and mediate SALM5-dependent presynaptic differentiation in contacting axons. In addition, SALM5 regulates AMPA receptor-mediated synaptic transmission through mechanisms involving the interaction of postsynaptic SALM5 with presynaptic LAR-RPTPs. These results suggest that postsynaptic SALM5 promotes synapse development by trans-synaptically interacting with presynaptic LAR-RPTPs and is important for the regulation of excitatory synaptic strength.
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Affiliation(s)
- Yeonsoo Choi
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Jungyong Nam
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Daniel J. Whitcomb
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, School of Clinical Sciences, Faculty of Health Sciences, University of Bristol, Whitson Street, Bristol BS1 3NY, United Kingdom
| | - Yoo Sung Song
- Department of Nuclear Medicine, Seoul National University Bundang Hospital, Gyeonggi-do, 463–707, Korea
| | - Doyoun Kim
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Sangmin Jeon
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | - Ji Won Um
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
- Department of Physiology and BK21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul 120-752, Korea
| | - Seong-Gyu Lee
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Jooyeon Woo
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Seok-Kyu Kwon
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 305-701, Korea
| | - Yan Li
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
| | - Won Mah
- Department of Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu, Korea
| | - Ho Min Kim
- Graduate School of Medical Science and Engineering, KAIST, Daejeon 305-701, Korea
| | - Jaewon Ko
- Department of Biochemistry, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | - Kwangwook Cho
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, School of Clinical Sciences, Faculty of Health Sciences, University of Bristol, Whitson Street, Bristol BS1 3NY, United Kingdom
- Centre for Synaptic Plasticity, University of Bristol, Bristol BS1 3NY, United Kingdom
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute for Science and Technology (KAIST), Daejeon 305-701, Korea
- Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, Korea
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