1
|
Zhao M, Gu H, Pan W, Liu P, Zhu T, Shang H, Jia M, Yang J. SynCAM1 deficiency in the hippocampal parvalbumin interneurons contributes to sevoflurane-induced cognitive impairment in neonatal rats. CNS Neurosci Ther 2024; 30:e14554. [PMID: 38105652 PMCID: PMC10805405 DOI: 10.1111/cns.14554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2023] [Revised: 11/20/2023] [Accepted: 11/23/2023] [Indexed: 12/19/2023] Open
Abstract
AIMS Sevoflurane is widely used for general anesthesia in children. Previous studies reported that multiple neonatal exposures to sevoflurane can induce long-term cognitive impairment in adolescent rats, but the underlying mechanisms were not defined. METHODS Postnatal day 6 (P6) to P8 rat pups were exposed to 30% oxygen with or without 3% sevoflurane balanced with air. The Y maze test (YMT) and Morris water maze (MWM) tests were performed in some cohorts from age P35 to assess cognitive functions, and their brain samples were harvested at age P14, 21, 28, 35, and 42 for measurements of various molecular entities and in vivo electrophysiology experiments at age P35. RESULTS Sevoflurane exposure resulted in cognitive impairment that was associated with decreased synCAM1 expression in parvalbumin (PV) interneurons, a reduction of PV phenotype, disturbed gamma oscillations, and dendritic spine loss in the hippocampal CA3 region. Enriched environment (EE) increased synCAM1 expression in the PV interneurons and attenuated sevoflurane-induced cognitive impairment. The synCAM1 overexpression by the adeno-associated virus vector in the hippocampal CA3 region restored sevoflurane-induced cognitive impairment, PV phenotype loss, gamma oscillations decrease, and dendritic spine loss. CONCLUSION Our data suggested that neonatal sevoflurane exposure results in cognitive impairment through decreased synCAM1 expression in PV interneurons in the hippocampus.
Collapse
Affiliation(s)
- Ming‐ming Zhao
- Department of Anesthesiology, Pain and Perioperative MedicineThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouChina
- Neuroscience Research Institute, Zhengzhou University Academy of Medical SciencesZhengzhou UniversityZhengzhouChina
| | - Han‐wen Gu
- Department of Anesthesiology, Pain and Perioperative MedicineThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouChina
- Neuroscience Research Institute, Zhengzhou University Academy of Medical SciencesZhengzhou UniversityZhengzhouChina
| | - Wei‐tong Pan
- Department of Anesthesiology, Pain and Perioperative MedicineThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouChina
- Neuroscience Research Institute, Zhengzhou University Academy of Medical SciencesZhengzhou UniversityZhengzhouChina
| | - Pan‐miao Liu
- Department of Anesthesiology, Pain and Perioperative MedicineThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouChina
- Neuroscience Research Institute, Zhengzhou University Academy of Medical SciencesZhengzhou UniversityZhengzhouChina
| | - Ting‐ting Zhu
- Department of Anesthesiology, Pain and Perioperative MedicineThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouChina
- Neuroscience Research Institute, Zhengzhou University Academy of Medical SciencesZhengzhou UniversityZhengzhouChina
| | - Hui‐jie Shang
- Department of Anesthesiology, Pain and Perioperative MedicineThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouChina
| | - Min Jia
- Department of Anesthesiology, Pain and Perioperative MedicineThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouChina
| | - Jian‐jun Yang
- Department of Anesthesiology, Pain and Perioperative MedicineThe First Affiliated Hospital of Zhengzhou UniversityZhengzhouChina
- Neuroscience Research Institute, Zhengzhou University Academy of Medical SciencesZhengzhou UniversityZhengzhouChina
| |
Collapse
|
2
|
Zhang L, Wei X. SynCAMs in Normal Vertebrate Neural Development and Neuropsychiatric Disorders: from the Perspective of the OCAs. Mol Neurobiol 2024; 61:358-371. [PMID: 37607992 DOI: 10.1007/s12035-023-03579-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Accepted: 08/14/2023] [Indexed: 08/24/2023]
Abstract
Neuronal synaptic junctions connect neurons to enable neuronal signal transmission in the nervous system. The proper establishment of synaptic connections required many adhesion molecules. Malfunctions of these adhesion molecules can result in neural development disorders and neuropsychiatric disorders. How specific synapses are established by various adhesion molecules for proper neural circuitry is a fundamental question of neuroscience. SynCAMs, also named CADMs, Necl, etc., are among the many adhesion proteins found in synapses. Here, we review the current understanding of the physical properties of SynCAMs and their roles in axon pathfinding, myelination, synaptogenesis, and synaptic plasticity. In addition, we discuss the involvement of SynCAMs in neuropsychiatric disorders. Finally, we propose that SynCAM functions can be better viewed and understood from the perspective of orientational cell adhesions (OCAs). In particular, we discuss the possibilities of how SynCAMs can be regulated at the cell-type specific expression, transcription variants, posttranslational modification, and subcellular localization to modulate the diversity of SynCAMs as OCA molecules. Being major components of the synapses, SynCAMs continue to be an important research topic of neuroscience, and many outstanding questions are waiting to be answered.
Collapse
Affiliation(s)
- Lili Zhang
- Department of Psychology, Dalian Medical University, Dalian, China.
| | - Xiangyun Wei
- Departments of Ophthalmology, Developmental Biology, and Microbiology & Molecular Genetics, University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
3
|
Pushkin AN, Kay Y, Herring BE. Protein 4.1N Plays a Cell Type-Specific Role in Hippocampal Glutamatergic Synapse Regulation. J Neurosci 2023; 43:8336-8347. [PMID: 37845032 PMCID: PMC10711697 DOI: 10.1523/jneurosci.0185-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 09/14/2023] [Accepted: 10/02/2023] [Indexed: 10/18/2023] Open
Abstract
Many glutamatergic synapse proteins contain a 4.1N protein binding domain. However, a role for 4.1N in the regulation of glutamatergic neurotransmission has been controversial. Here, we observe significantly higher expression of protein 4.1N in granule neurons of the dentate gyrus (DG granule neurons) compared with other hippocampal regions. We discover that reducing 4.1N expression in rat DG granule neurons of either sex results in a significant reduction in glutamatergic synapse function that is caused by a decrease in the number of glutamatergic synapses. By contrast, we find reduction of 4.1N expression in hippocampal CA1 pyramidal neurons has no impact on basal glutamatergic neurotransmission. We also find 4.1N's C-terminal domain (CTD) to be nonessential to its role in the regulation of glutamatergic synapses of DG granule neurons. Instead, we show that 4.1N's four-point-one, ezrin, radixin, and moesin (FERM) domain is essential for supporting synaptic AMPA receptor (AMPAR) function in these neurons. Altogether, this work demonstrates a novel, cell type-specific role for protein 4.1N in governing glutamatergic synapse function.SIGNIFICANCE STATEMENT Glutamatergic synapses exhibit immense molecular diversity. In comparison to heavily studied Schaffer collateral, CA1 glutamatergic synapses, significantly less is known about perforant path-dentate gyrus (DG) synapses. Our data demonstrate that compromising 4.1N function in CA1 pyramidal neurons produces no alteration in basal glutamatergic synaptic transmission. However, in DG granule neurons, compromising 4.1N function leads to a significant decrease in the strength of glutamatergic neurotransmission at perforant pathway synapses. Together, our data identifies 4.1N as a cell type-specific regulator of synaptic transmission within the hippocampus and reveals a unique molecular program that governs perforant pathway synapse function.
Collapse
Affiliation(s)
- Anna N Pushkin
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California 90089
| | - Yuni Kay
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California 90089
| | - Bruce E Herring
- Neuroscience Graduate Program, University of Southern California, Los Angeles, California 90089
- Department of Biological Sciences, Neurobiology Section, Dornslife College of Letters, Arts, and Sciences, University of Southern California, Los Angeles, California 90089
| |
Collapse
|
4
|
Yang Q, Liu J, Wang Z. 4.1N-Mediated Interactions and Functions in Nerve System and Cancer. Front Mol Biosci 2021; 8:711302. [PMID: 34589518 PMCID: PMC8473747 DOI: 10.3389/fmolb.2021.711302] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Accepted: 08/16/2021] [Indexed: 01/05/2023] Open
Abstract
Scaffolding protein 4.1N is a neuron-enriched 4.1 homologue. 4.1N contains three conserved domains, including the N-terminal 4.1-ezrin-radixin-moesin (FERM) domain, internal spectrin–actin–binding (SAB) domain, and C-terminal domain (CTD). Interspersed between the three domains are nonconserved domains, including U1, U2, and U3. The role of 4.1N was first reported in the nerve system. Then, extensive studies reported the role of 4.1N in cancers and other diseases. 4.1N performs numerous vital functions in signaling transduction by interacting, locating, supporting, and coordinating different partners and is involved in the molecular pathogenesis of various diseases. In this review, recent studies on the interactions between 4.1N and its contactors (including the α7AChr, IP3R1, GluR1/4, GluK1/2/3, mGluR8, KCC2, D2/3Rs, CASK, NuMA, PIKE, IP6K2, CAM 1/3, βII spectrin, flotillin-1, pp1, and 14-3-3) and the 4.1N-related biological functions in the nerve system and cancers are specifically and comprehensively discussed. This review provides critical detailed mechanistic insights into the role of 4.1N in disease relationships.
Collapse
Affiliation(s)
- Qin Yang
- Molecular Biology Research Center & Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China.,School of Medical Laboratory, Shao Yang University, Shaoyang, China
| | - Jing Liu
- Molecular Biology Research Center & Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| | - Zi Wang
- Molecular Biology Research Center & Center for Medical Genetics, School of Life Sciences, Central South University, Changsha, China
| |
Collapse
|
5
|
Zhang Q, Zhang J, Ye J, Li X, Liu H, Ma X, Wang C, He K, Zhang W, Yuan J, Zhao Y, Xu H, Liu Q. Nuclear speckle specific hnRNP D-like prevents age- and AD-related cognitive decline by modulating RNA splicing. Mol Neurodegener 2021; 16:66. [PMID: 34551807 PMCID: PMC8456587 DOI: 10.1186/s13024-021-00485-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 08/12/2021] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Aberrant alternative splicing plays critical role in aging and age-related diseases. Heterogeneous nuclear ribonucleoproteins (hnRNPs) reportedly regulate RNA splicing process. Whether and how hnRNPs contribute to age-related neurodegenerative diseases, especially Alzheimer's disease (AD), remain elusive. METHODS Immunoblotting and immunostaining were performed to determine expression patterns and cellular/subcellular localization of the long isoform of hnRNP D-like (L-DL), which is a hnRNP family member, in mouse hippocampus. Downregulation of L-DL in WT mice was achieved by AAV-mediated shRNA delivery, followed by memory-related behavioural tests. L-DL interactome was analysed by affinity-precipitation and mass spectrometry. Alternative RNA splicing was measured by RNA-seq and analyzed by bioinformatics-based approaches. Downregulation and upregulation of L-DL in APP/PS1 mice were performed using AAV-mediated transduction. RESULTS We show that L-DL is specifically localized to nuclear speckles. L-DL levels are decreased in the hippocampus of aged mouse brains and downregulation of L-DL impairs cognition in mice. L-DL serves as a structural component to recruit other speckle proteins, and regulates cytoskeleton- and synapse-related gene expression by altering RNA splicing. Mechanistically, these splicing changes are modulated via L-DL-mediated interaction of SF3B3, a core component of U2 snRNP, and U2AF65, a U2 spliceosome protein that guides U2 snRNP's binding to RNA. In addition, L-DL levels are decreased in APP/PS1 mouse brains. While downregulation of L-DL deteriorates memory deficits and overexpression of L-DL improves cognitive function in AD mice, by regulating the alternative splicing and expression of synaptic gene CAMKV. CONCLUSIONS Our findings define a molecular mechanism by which hnRNP L-DL regulates alternative RNA splicing, and establish a direct role for L-DL in AD-related synaptic dysfunction and memory decline.
Collapse
Affiliation(s)
- Qingyang Zhang
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
| | - Juan Zhang
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.,Anhui Province Key Laboratory of Biomedical Aging Research, University of Science and Technology of China, Hefei, 230026, China
| | - Jin Ye
- School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
| | - Xiaohui Li
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China.,Anhui Province Key Laboratory of Biomedical Aging Research, University of Science and Technology of China, Hefei, 230026, China
| | - Hongda Liu
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
| | - Xiaolin Ma
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
| | - Chao Wang
- School of Life Sciences, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China
| | - Keqiang He
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230001, China
| | - Wei Zhang
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230001, China
| | - Ji Yuan
- Department of Anesthesiology, The First Affiliated Hospital of USTC, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230001, China
| | - Yingjun Zhao
- The First Affiliated Hospital of Xiamen University, Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Xiamen University, Xiamen, 361000, China
| | - Huaxi Xu
- The First Affiliated Hospital of Xiamen University, Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, Xiamen University, Xiamen, 361000, China.
| | - Qiang Liu
- Institute on Aging and Brain Disorders, The First Affiliated Hospital of USTC, Hefei National Laboratory for Physical Sciences at the Microscale, Division of Life Sciences and Medicine, University of Science and Technology of China, Hefei, 230026, China. .,Anhui Province Key Laboratory of Biomedical Aging Research, University of Science and Technology of China, Hefei, 230026, China. .,Center for Excellence in Animal Evolution and Genetics, Chinese Academy of Sciences, Kunming, 650201, China.
| |
Collapse
|
6
|
Nectins and Nectin-like molecules in synapse formation and involvement in neurological diseases. Mol Cell Neurosci 2021; 115:103653. [PMID: 34242750 DOI: 10.1016/j.mcn.2021.103653] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 05/11/2021] [Accepted: 06/25/2021] [Indexed: 12/12/2022] Open
Abstract
Synapses are interneuronal junctions which form neuronal networks and play roles in a variety of functions, including learning and memory. Two types of junctions, synaptic junctions (SJs) and puncta adherentia junctions (PAJs), have been identified. SJs are found at all excitatory and inhibitory synapses whereas PAJs are found at excitatory synapses, but not inhibitory synapses, and particularly well developed at hippocampal mossy fiber giant excitatory synapses. Both SJs and PAJs are mediated by cell adhesion molecules (CAMs). Major CAMs at SJs are neuroligins-neurexins and Nectin-like molecules (Necls)/CADMs/SynCAMs whereas those at PAJs are nectins and cadherins. In addition to synaptic PAJs, extrasynaptic PAJs have been identified at contact sites between neighboring dendrites near synapses and regulate synapse formation. In addition to SJs and PAJs, a new type of cell adhesion apparatus different from these junctional apparatuses has been identified and named nectin/Necl spots. One nectin spot at contact sites between neighboring dendrites at extrasynaptic regions near synapses regulates synapse formation. Several members of nectins and Necls had been identified as viral receptors before finding their physiological functions as CAMs and evidence is accumulating that many nectins and Necls are related to onset and progression of neurological diseases. We review here nectin and Necls in synapse formation and involvement in neurological diseases.
Collapse
|
7
|
Differential Contribution of Cadm1-Cadm3 Cell Adhesion Molecules to Peripheral Myelinated Axons. J Neurosci 2021; 41:1393-1400. [PMID: 33397712 DOI: 10.1523/jneurosci.2736-20.2020] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2020] [Accepted: 11/18/2020] [Indexed: 12/14/2022] Open
Abstract
Cell adhesion proteins of the Cadm (SynCAM/Necl) family regulate myelination and the organization of myelinated axons. In the peripheral nervous system (PNS), intercellular contact between Schwann cells and their underlying axons is believed to be mediated by binding of glial Cadm4 to axonal Cadm3 or Cadm2. Nevertheless, given that distinct neurons express different combinations of the Cadm proteins, the identity of the functional axonal ligand for Cadm4 remains to be determined. Here, we took a genetic approach to compare the phenotype of Cadm4 null mice, which exhibit abnormal distribution of Caspr and Kv1 potassium channels, with mice lacking different combinations of Cadm1-Cadm3 genes. We show that in contrast to mice lacking the single Cadm1, Cadm2, or Cadm3 genes, genetic ablation of all three phenocopies the abnormalities detected in the absence of Cadm4. Similar defects were observed in double mutant mice lacking Cadm3 and Cadm2 (i.e., Cadm3 -/- /Cadm2 -/-) or Cadm3 and Cadm1 (i.e., Cadm3 -/- /Cadm1 -/-), but not in mice lacking Cadm1 and Cadm2 (i.e., Cadm1 -/- /Cadm2 -/-). Furthermore, axonal organization abnormalities were also detected in Cadm3 null mice that were heterozygous for the two other axonal Cadms. Our results identify Cadm3 as the main axonal ligand for glial Cadm4, and reveal that its absence could be compensated by the combined action of Cadm2 and Cadm1.SIGNIFICANCE STATEMENT Myelination by Schwann cells enables fast conduction of action potentials along motor and sensory axons. In these nerves, Schwann cell-axon contact is mediated by cell adhesion molecules of the Cadm family. Cadm4 in Schwann cells regulates axonal ensheathment and myelin wrapping, as well as the organization of the axonal membrane, but the identity of its axonal ligands is not clear. Here, we reveal that Cadm mediated axon-glia interactions depend on a hierarchical adhesion code that involves multiple family members. Our results provide important insights into the molecular mechanisms of axon-glia communication, and the function of Cadm proteins in PNS myelin.
Collapse
|
8
|
Zeng X, Niu Y, Qin G, Zhang D, Zhou J, Chen L. Deficiency in the function of inhibitory interneurons contributes to glutamate-associated central sensitization through GABABR2-SynCAM1 signaling in chronic migraine rats. FASEB J 2020; 34:14780-14798. [PMID: 32931071 DOI: 10.1096/fj.202001561r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 08/11/2020] [Accepted: 08/24/2020] [Indexed: 01/03/2023]
Abstract
The occurrence of pain has always been closely related to a break in the balance between excitatory and inhibitory systems, and the internal relationship between these two systems has not been studied in the pathogenesis of chronic migraine (CM). In this study, we explored how inhibitory interneurons specifically modulate the glutamate-induced hyperexcitability in the periaqueductal gray (PAG) of CM rats. The CM model was established by repeated dural infusion of inflammatory soup (IS) in rats. Then, Baclofen, a gamma-aminobutyric acid type B receptor (GABABR) agonist; CGP35348, a GABABR antagonist; H89, a protein kinase A (PKA) inhibitor; and 8-Bromo-cAMP, a PKA agonist, were applied by intraventricular injection to investigate the detailed CM mechanism. Our results showed that GABABR2 mRNA and protein levels were significantly downregulated (P < .01) in the PAG of CM rats. Similarly, gamma-aminobutyric acid (GABA) and its synthetase glutamate decarboxylase 65/67 (GAD65/67) seriously decreased (P < .01), implying a deficit in the function of inhibitory interneurons in the PAG of CM rats. Afterward, the application of Baclofen and H89 alleviated the IS-evoked hyperalgesia and extenuated vesicular glutamate transporter 2 (VGLUT2), glutamate, calcitonin gene-related peptide (CGRP), and c-Fos expression by regulating the GABABR2/PKA/SynCAM1 pathway in the PAG of CM rats, while the application of CGP35348 and 8-Bromo-cAMP exactly exerted the opposite effect. Importantly, CGP35348 induced an elevation of CGRP, and VGLUT2 expression was relieved by H89. These data suggest that the loss in the function of inhibitory interneurons contributes to glutamate-associated central sensitization through the GABABR2/PKA/SynCAM1 pathway in the PAG of CM rats.
Collapse
Affiliation(s)
- Xiaoxu Zeng
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yingying Niu
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Guangcheng Qin
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Dunke Zhang
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jiying Zhou
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Lixue Chen
- Laboratory Research Center, The First Affiliated Hospital of Chongqing Medical University, Chongqing, China
| |
Collapse
|
9
|
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: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [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.
Collapse
|
10
|
Emerging Roles of Synapse Organizers in the Regulation of Critical Periods. Neural Plast 2019; 2019:1538137. [PMID: 31565044 PMCID: PMC6745111 DOI: 10.1155/2019/1538137] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 07/09/2019] [Accepted: 07/25/2019] [Indexed: 01/10/2023] Open
Abstract
Experience remodels cortical connectivity during developmental windows called critical periods. Experience-dependent regulation of synaptic strength during these periods establishes circuit functions that are stabilized as critical period plasticity wanes. These processes have been extensively studied in the developing visual cortex, where critical period opening and closure are orchestrated by the assembly, maturation, and strengthening of distinct synapse types. The synaptic specificity of these processes points towards the involvement of distinct molecular pathways. Attractive candidates are pre- and postsynaptic transmembrane proteins that form adhesive complexes across the synaptic cleft. These synapse-organizing proteins control synapse development and maintenance and modulate structural and functional properties of synapses. Recent evidence suggests that they have pivotal roles in the onset and closure of the critical period for vision. In this review, we describe roles of synapse-organizing adhesion molecules in the regulation of visual critical period plasticity and we discuss the potential they offer to restore circuit functions in amblyopia and other neurodevelopmental disorders.
Collapse
|
11
|
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.
Collapse
Affiliation(s)
- Scott Cameron
- Center for Neuroscience, University of California, Davis, California 95618, USA; ,
| | | |
Collapse
|
12
|
Fierro J, Haynes DR, Washbourne P. 4.1Ba is necessary for glutamatergic synapse formation in the sensorimotor circuit of developing zebrafish. PLoS One 2018; 13:e0205255. [PMID: 30286167 PMCID: PMC6171929 DOI: 10.1371/journal.pone.0205255] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Accepted: 09/23/2018] [Indexed: 01/04/2023] Open
Abstract
During the process of synapse formation, thousands of proteins assemble at prospective sites of cell-cell communication. Although many of these proteins have been identified, the roles they play in generating functional connections during development remain unknown. 4.1 scaffolding proteins have been implicated in synapse formation and maturation in vitro, but in vivo studies for some family members have suggested these proteins are not important for this role. We examined the role of family member 4.1B because it has been implicated in glutamatergic synaptogenesis, but has not been described in vivo. We identified two 4.1B genes in zebrafish, 4.1Ba and 4.1Bb, by sequence comparisons and synteny analysis. In situ hybridization shows these genes are differentially expressed, with 4.1Ba expressed primarily in the nervous system and 4.1Bb expressed in the nervous system and muscle, but not the spinal cord. We focused our studies on 4.1Ba in the spinal cord. 4.1Ba knockdown reduced the number of glutamatergic synapses at caudal primary motor neurons and caused an increase in the duration of touch-evoked coiling. These results suggest 4.1Ba is important for the formation of functional glutamatergic synapses in the developing zebrafish spinal cord.
Collapse
Affiliation(s)
- Javier Fierro
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, United States of America
| | - Dylan R. Haynes
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, United States of America
| | - Philip Washbourne
- Institute of Neuroscience, University of Oregon, Eugene, Oregon, United States of America
| |
Collapse
|
13
|
Long-term treadmill exercise improves memory impairment through restoration of decreased synaptic adhesion molecule 1/2/3 induced by transient cerebral ischemia in the aged gerbil hippocampus. Exp Gerontol 2018; 103:124-131. [DOI: 10.1016/j.exger.2018.01.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 01/05/2018] [Accepted: 01/12/2018] [Indexed: 01/13/2023]
|
14
|
Fowler DK, Peters JH, Williams C, Washbourne P. Redundant Postsynaptic Functions of SynCAMs 1-3 during Synapse Formation. Front Mol Neurosci 2017; 10:24. [PMID: 28197078 PMCID: PMC5281628 DOI: 10.3389/fnmol.2017.00024] [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: 12/07/2016] [Accepted: 01/17/2017] [Indexed: 01/13/2023] Open
Abstract
Investigating the roles of synaptogenic adhesion molecules during synapse formation has proven challenging, often due to compensatory functions between additional family members. The synaptic cell adhesion molecules 1–3 (SynCAM1–3) are expressed both pre- and postsynaptically, share highly homologous domains and are synaptogenic when ectopically presented to neurons; yet their endogenous functions during synaptogenesis are unclear. Here we report that SynCAM1–3 are functionally redundant and collectively necessary for synapse formation in cultured hippocampal neurons. Only triple knockdown (KD) of SynCAM1–3 using highly efficient, chained artificial microRNAs (amiRNAs) reduced synapse density and increased synapse area. Electrophysiological recordings of quantal release events supported an increase in synapse size caused by SynCAM1–3 depletion. Furthermore, a combinatorial, mosaic lentiviral approach comparing wild type (WT) and SynCAM1–3 KD neurons in the same culture demonstrate that SynCAM1–3 set synapse number and size through postsynaptic mechanisms. The results demonstrate that the redundancy between SynCAM1–3 has concealed their synaptogenic function at the postsynaptic terminal.
Collapse
Affiliation(s)
- Daniel K Fowler
- Department of Biology, Institute of Neuroscience, University of OregonEugene, OR, USA; Department of Integrative Physiology and Neuroscience, Washington State UniversityPullman, WA, USA
| | - James H Peters
- Department of Integrative Physiology and Neuroscience, Washington State University Pullman, WA, USA
| | - Carly Williams
- Department of Biology, Institute of Neuroscience, University of Oregon Eugene, OR, USA
| | - Philip Washbourne
- Department of Biology, Institute of Neuroscience, University of Oregon Eugene, OR, USA
| |
Collapse
|
15
|
Frei JA, Stoeckli ET. SynCAMs - From axon guidance to neurodevelopmental disorders. Mol Cell Neurosci 2016; 81:41-48. [PMID: 27594578 DOI: 10.1016/j.mcn.2016.08.012] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2016] [Revised: 08/28/2016] [Accepted: 08/31/2016] [Indexed: 12/22/2022] Open
Abstract
Many cell adhesion molecules are located at synapses but only few of them can be considered synaptic cell adhesion molecules in the strict sense. Besides the Neurexins and Neuroligins, the LRRTMs (leucine rich repeat transmembrane proteins) and the SynCAMs/CADMs can induce synapse formation when expressed in non-neuronal cells and therefore are true synaptic cell adhesion molecules. SynCAMs (synaptic cell adhesion molecules) are a subfamily of the immunoglobulin superfamily of cell adhesion molecules. As suggested by their name, they were first identified as cell adhesion molecules at the synapse which were sufficient to trigger synapse formation. They also contribute to myelination by mediating axon-glia cell contacts. More recently, their role in earlier stages of neural circuit formation was demonstrated, as they also guide axons both in the peripheral and in the central nervous system. Mutations in SynCAM genes were found in patients diagnosed with autism spectrum disorders. The diverse functions of SynCAMs during development suggest that neurodevelopmental disorders are not only due to defects in synaptic plasticity. Rather, early steps of neural circuit formation are likely to contribute.
Collapse
Affiliation(s)
- Jeannine A Frei
- Hussman Institute for Autism, 801 W Baltimore Street, Baltimore, MD 20201, United States
| | - Esther T Stoeckli
- Dept of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
| |
Collapse
|
16
|
Fowler DK, Williams C, Gerritsen AT, Washbourne P. Improved knockdown from artificial microRNAs in an enhanced miR-155 backbone: a designer's guide to potent multi-target RNAi. Nucleic Acids Res 2015; 44:e48. [PMID: 26582923 PMCID: PMC4797272 DOI: 10.1093/nar/gkv1246] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2015] [Accepted: 10/31/2015] [Indexed: 01/24/2023] Open
Abstract
Artificial microRNA (amiRNA) sequences embedded in natural microRNA (miRNA) backbones have proven to be useful tools for RNA interference (RNAi). amiRNAs have reduced off-target and toxic effects compared to other RNAi-based methods such as short-hairpin RNAs (shRNA). amiRNAs are often less effective for knockdown, however, compared to their shRNA counterparts. We screened a large empirically-designed amiRNA set in the synthetic inhibitory BIC/miR-155 RNA (SIBR) scaffold and show common structural and sequence-specific features associated with effective amiRNAs. We then introduced exogenous motifs into the basal stem region which increase amiRNA biogenesis and knockdown potency. We call this modified backbone the enhanced SIBR (eSIBR) scaffold. Using chained amiRNAs for multi-gene knockdown, we show that concatenation of miRNAs targeting different genes is itself sufficient for increased knockdown efficacy. Further, we show that eSIBR outperforms wild-type SIBR (wtSIBR) when amiRNAs are chained. Finally, we use a lentiviral expression system in cultured neurons, where we again find that eSIBR amiRNAs are more potent for multi-target knockdown of endogenous genes. eSIBR will be a valuable tool for RNAi approaches, especially for studies where knockdown of multiple targets is desired.
Collapse
Affiliation(s)
- Daniel K Fowler
- Institute of Molecular Biology, University of Oregon, Eugene, OR 97403, USA Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Carly Williams
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| | - Alida T Gerritsen
- Institute for Bioinformatics and Evolutionary Studies, University of Idaho, Moscow, ID 83844, USA
| | - Philip Washbourne
- Institute of Neuroscience, University of Oregon, Eugene, OR 97403, USA
| |
Collapse
|
17
|
Tabet AC, Verloes A, Pilorge M, Delaby E, Delorme R, Nygren G, Devillard F, Gérard M, Passemard S, Héron D, Siffroi JP, Jacquette A, Delahaye A, Perrin L, Dupont C, Aboura A, Bitoun P, Coleman M, Leboyer M, Gillberg C, Benzacken B, Betancur C. Complex nature of apparently balanced chromosomal rearrangements in patients with autism spectrum disorder. Mol Autism 2015; 6:19. [PMID: 25844147 PMCID: PMC4384291 DOI: 10.1186/s13229-015-0015-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2014] [Accepted: 03/06/2015] [Indexed: 12/21/2022] Open
Abstract
Background Apparently balanced chromosomal rearrangements can be associated with an abnormal phenotype, including intellectual disability and autism spectrum disorder (ASD). Genome-wide microarrays reveal cryptic genomic imbalances, related or not to the breakpoints, in 25% to 50% of patients with an abnormal phenotype carrying a microscopically balanced chromosomal rearrangement. Here we performed microarray analysis of 18 patients with ASD carrying balanced chromosomal abnormalities to identify submicroscopic imbalances implicated in abnormal neurodevelopment. Methods Eighteen patients with ASD carrying apparently balanced chromosomal abnormalities were screened using single nucleotide polymorphism (SNP) arrays. Nine rearrangements were de novo, seven inherited, and two of unknown inheritance. Genomic imbalances were confirmed by fluorescence in situ hybridization and quantitative PCR. Results We detected clinically significant de novo copy number variants in four patients (22%), including three with de novo rearrangements and one with an inherited abnormality. The sizes ranged from 3.3 to 4.9 Mb; three were related to the breakpoint regions and one occurred elsewhere. We report a patient with a duplication of the Wolf-Hirschhorn syndrome critical region, contributing to the delineation of this rare genomic disorder. The patient has a chromosome 4p inverted duplication deletion, with a 0.5 Mb deletion of terminal 4p and a 4.2 Mb duplication of 4p16.2p16.3. The other cases included an apparently balanced de novo translocation t(5;18)(q12;p11.2) with a 4.2 Mb deletion at the 18p breakpoint, a subject with de novo pericentric inversion inv(11)(p14q23.2) in whom the array revealed a de novo 4.9 Mb deletion in 7q21.3q22.1, and a patient with a maternal inv(2)(q14.2q37.3) with a de novo 3.3 Mb terminal 2q deletion and a 4.2 Mb duplication at the proximal breakpoint. In addition, we identified a rare de novo deletion of unknown significance on a chromosome unrelated to the initial rearrangement, disrupting a single gene, RFX3. Conclusions These findings underscore the utility of SNP arrays for investigating apparently balanced chromosomal abnormalities in subjects with ASD or related neurodevelopmental disorders in both clinical and research settings.
Collapse
Affiliation(s)
- Anne-Claude Tabet
- Department of Genetics, AP-HP, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France ; INSERM, UMR 1130, Neuroscience Paris Seine, 9 quai Saint Bernard, 75005 Paris, France ; CNRS, UMR 8246, Neuroscience Paris Seine, 9 quai Saint Bernard, 75005 Paris, France ; Sorbonne Universités, UPMC Univ Paris 6, Institut de Biologie Paris-Seine, 9 quai Saint Bernard, 75005 Paris, France
| | - Alain Verloes
- Department of Genetics, AP-HP, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France ; INSERM, UMR 1141, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France
| | - Marion Pilorge
- INSERM, UMR 1130, Neuroscience Paris Seine, 9 quai Saint Bernard, 75005 Paris, France ; CNRS, UMR 8246, Neuroscience Paris Seine, 9 quai Saint Bernard, 75005 Paris, France ; Sorbonne Universités, UPMC Univ Paris 6, Institut de Biologie Paris-Seine, 9 quai Saint Bernard, 75005 Paris, France
| | - Elsa Delaby
- INSERM, UMR 1130, Neuroscience Paris Seine, 9 quai Saint Bernard, 75005 Paris, France ; CNRS, UMR 8246, Neuroscience Paris Seine, 9 quai Saint Bernard, 75005 Paris, France ; Sorbonne Universités, UPMC Univ Paris 6, Institut de Biologie Paris-Seine, 9 quai Saint Bernard, 75005 Paris, France
| | - Richard Delorme
- Department of Child and Adolescent Psychiatry, AP-HP, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France ; Fondation Fondamental, 40 rue de Mesly, 94000 Créteil, France
| | - Gudrun Nygren
- Gillberg Neuropsychiatry Centre, University of Gothenburg, Kungsgatan 12, 41119 Göteborg, Sweden
| | - Françoise Devillard
- Département de Génétique et Procréation, CHU de Grenoble, Hôpital Couple-Enfant, avenue du Maquis du Grésivaudan, 38043 Grenoble, France
| | - Marion Gérard
- Department of Genetics, AP-HP, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France
| | - Sandrine Passemard
- INSERM, UMR 1141, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France ; Neurology Unit, AP-HP, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France
| | - Delphine Héron
- Medical Genetics Unit, AP-HP, Pitié-Salpêtrière University Hospital, 47 boulevard de l'Hôpital, 75013 Paris, France
| | - Jean-Pierre Siffroi
- Service de Génétique et d'Embryologie Médicales, AP-HP, Trousseau Hospital, 26 avenue du Docteur Arnold Netter, 75012 Paris, France
| | - Aurelia Jacquette
- Medical Genetics Unit, AP-HP, Pitié-Salpêtrière University Hospital, 47 boulevard de l'Hôpital, 75013 Paris, France
| | - Andrée Delahaye
- INSERM, UMR 1141, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France ; Cytogenetics Unit, AP-HP, Jean Verdier Hospital, allée du 14 Juillet, 93140 Bondy, France ; Paris 13 University, Sorbonne Paris Cité, UFR SMBH, 74 rue Marcel Cachin, 93000 Bobigny, France
| | - Laurence Perrin
- Department of Genetics, AP-HP, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France
| | - Céline Dupont
- Department of Genetics, AP-HP, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France
| | - Azzedine Aboura
- Department of Genetics, AP-HP, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France
| | - Pierre Bitoun
- Medical Genetics Unit, AP-HP, Jean Verdier Hospital, allée du 14 Juillet, 93140 Bondy, France
| | - Mary Coleman
- Foundation for Autism Research, 3081 Quail Hollow, Sarasota, FL 34235 USA
| | - Marion Leboyer
- Fondation Fondamental, 40 rue de Mesly, 94000 Créteil, France ; Department of Psychiatry, AP-HP, Henri Mondor-Albert Chenevier Hospital, 40 rue de Mesly, 94000 Créteil, France ; INSERM U955, Institut Mondor de Recherche Biomédicale, Psychiatric Genetics, 8 rue du Général Sarrail, 94000 Créteil, France ; Faculty of Medicine, University Paris-Est Créteil, 8 rue du Général Sarrail, 94000 Créteil, France
| | - Christopher Gillberg
- Gillberg Neuropsychiatry Centre, University of Gothenburg, Kungsgatan 12, 41119 Göteborg, Sweden
| | - Brigitte Benzacken
- Department of Genetics, AP-HP, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France ; INSERM, UMR 1141, Robert Debré University Hospital, 48 boulevard Sérurier, 75019 Paris, France ; Cytogenetics Unit, AP-HP, Jean Verdier Hospital, allée du 14 Juillet, 93140 Bondy, France ; Paris 13 University, Sorbonne Paris Cité, UFR SMBH, 74 rue Marcel Cachin, 93000 Bobigny, France
| | - Catalina Betancur
- INSERM, UMR 1130, Neuroscience Paris Seine, 9 quai Saint Bernard, 75005 Paris, France ; CNRS, UMR 8246, Neuroscience Paris Seine, 9 quai Saint Bernard, 75005 Paris, France ; Sorbonne Universités, UPMC Univ Paris 6, Institut de Biologie Paris-Seine, 9 quai Saint Bernard, 75005 Paris, France
| |
Collapse
|
18
|
Frei JA, Andermatt I, Gesemann M, Stoeckli ET. The SynCAM synaptic cell adhesion molecules are involved in sensory axon pathfinding by regulating axon-axon contacts. J Cell Sci 2014; 127:5288-302. [PMID: 25335893 DOI: 10.1242/jcs.157032] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Synaptic cell adhesion molecules (SynCAMs) are crucial for synapse formation and plasticity. However, we have previously demonstrated that SynCAMs are also required during earlier stages of neural circuit formation because SynCAM1 and SynCAM2 (also known as CADM1 and CADM2, respectively) are important for the guidance of post-crossing commissural axons. In contrast to the exclusively homophilic cis-interactions reported by previous studies, our previous in vivo results suggested the existence of heterophilic cis-interactions between SynCAM1 and SynCAM2. Indeed, as we show here, the presence of homophilic and heterophilic cis-interactions modulates the interaction of SynCAMs with trans-binding partners, as observed previously for other immunoglobulin superfamily cell adhesion molecules. These in vitro findings are in agreement with results from in vivo studies, which demonstrate a role for SynCAMs in the formation of sensory neural circuits in the chicken embryo. In the absence of SynCAMs, selective axon-axon interactions are perturbed resulting in aberrant pathfinding of sensory axons.
Collapse
Affiliation(s)
- Jeannine A Frei
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Irwin Andermatt
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Matthias Gesemann
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| | - Esther T Stoeckli
- Institute of Molecular Life Sciences and Neuroscience Center Zurich, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland
| |
Collapse
|
19
|
Bellot A, Guivernau B, Tajes M, Bosch-Morató M, Valls-Comamala V, Muñoz FJ. The structure and function of actin cytoskeleton in mature glutamatergic dendritic spines. Brain Res 2014; 1573:1-16. [DOI: 10.1016/j.brainres.2014.05.024] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/12/2014] [Accepted: 05/13/2014] [Indexed: 12/01/2022]
|
20
|
Bury LA, Sabo SL. Dynamic mechanisms of neuroligin-dependent presynaptic terminal assembly in living cortical neurons. Neural Dev 2014; 9:13. [PMID: 24885664 PMCID: PMC4049477 DOI: 10.1186/1749-8104-9-13] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 05/12/2014] [Indexed: 12/23/2022] Open
Abstract
Background Synapse formation occurs when synaptogenic signals trigger coordinated development of pre and postsynaptic structures. One of the best-characterized synaptogenic signals is trans-synaptic adhesion. However, it remains unclear how synaptic proteins are recruited to sites of adhesion. In particular, it is unknown whether synaptogenic signals attract synaptic vesicle (SV) and active zone (AZ) proteins to nascent synapses or instead predominantly function to create sites that are capable of forming synapses. It is also unclear how labile synaptic proteins are at developing synapses after their initial recruitment. To address these issues, we used long-term, live confocal imaging of presynaptic terminal formation in cultured cortical neurons after contact with the synaptogenic postsynaptic adhesion proteins neuroligin-1 or SynCAM-1. Results Surprisingly, we find that trans-synaptic adhesion does not attract SV or AZ proteins nor alter their transport. In addition, although neurexin (the presynaptic partner of neuroligin) typically accumulates over the entire region of contact between axons and neuroligin-1-expressing cells, SV proteins selectively assemble at spots of enhanced neurexin clustering. The arrival and maintenance of SV proteins at these sites is highly variable over the course of minutes to hours, and this variability correlates with neurexin levels at individual synapses. Conclusions Together, our data support a model of synaptogenesis where presynaptic proteins are trapped at specific axonal sites, where they are stabilized by trans-synaptic adhesion signaling.
Collapse
Affiliation(s)
| | - Shasta L Sabo
- Department of Pharmacology, Case Western Reserve University School of Medicine, Cleveland, OH 44106, USA.
| |
Collapse
|
21
|
Yang X, Hou D, Jiang W, Zhang C. Intercellular protein-protein interactions at synapses. Protein Cell 2014; 5:420-44. [PMID: 24756565 PMCID: PMC4026422 DOI: 10.1007/s13238-014-0054-z] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2014] [Accepted: 03/23/2014] [Indexed: 12/11/2022] Open
Abstract
Chemical synapses are asymmetric intercellular junctions through which neurons send nerve impulses to communicate with other neurons or excitable cells. The appropriate formation of synapses, both spatially and temporally, is essential for brain function and depends on the intercellular protein-protein interactions of cell adhesion molecules (CAMs) at synaptic clefts. The CAM proteins link pre- and post-synaptic sites, and play essential roles in promoting synapse formation and maturation, maintaining synapse number and type, accumulating neurotransmitter receptors and ion channels, controlling neuronal differentiation, and even regulating synaptic plasticity directly. Alteration of the interactions of CAMs leads to structural and functional impairments, which results in many neurological disorders, such as autism, Alzheimer's disease and schizophrenia. Therefore, it is crucial to understand the functions of CAMs during development and in the mature neural system, as well as in the pathogenesis of some neurological disorders. Here, we review the function of the major classes of CAMs, and how dysfunction of CAMs relates to several neurological disorders.
Collapse
Affiliation(s)
- Xiaofei Yang
- Key Laboratory of Cognitive Science, Laboratory of Membrane Ion Channels and Medicine, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, 430074 China
| | - Dongmei Hou
- Key Laboratory of Cognitive Science, Laboratory of Membrane Ion Channels and Medicine, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, 430074 China
- State Key Laboratory of Biomembrane and Membrane Biotechnology, College of Life Sciences, Peking University, Beijing, 100871 China
- PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871 China
| | - Wei Jiang
- Key Laboratory of Cognitive Science, Laboratory of Membrane Ion Channels and Medicine, College of Biomedical Engineering, South-Central University for Nationalities, Wuhan, 430074 China
- State Key Laboratory of Biomembrane and Membrane Biotechnology, College of Life Sciences, Peking University, Beijing, 100871 China
- PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871 China
| | - Chen Zhang
- State Key Laboratory of Biomembrane and Membrane Biotechnology, College of Life Sciences, Peking University, Beijing, 100871 China
- PKU-IDG/McGovern Institute for Brain Research, Peking University, Beijing, 100871 China
| |
Collapse
|
22
|
Frei JA, Stoeckli ET. SynCAMs extend their functions beyond the synapse. Eur J Neurosci 2014; 39:1752-60. [DOI: 10.1111/ejn.12544] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Revised: 01/17/2014] [Accepted: 02/03/2014] [Indexed: 02/06/2023]
Affiliation(s)
- Jeannine A. Frei
- Institute of Molecular Life Sciences and Neuroscience Center Zurich; University of Zurich; Winterthurerstrasse 190 8057 Zurich Switzerland
| | - Esther T. Stoeckli
- Institute of Molecular Life Sciences and Neuroscience Center Zurich; University of Zurich; Winterthurerstrasse 190 8057 Zurich Switzerland
| |
Collapse
|
23
|
Baines AJ, Lu HC, Bennett PM. The Protein 4.1 family: hub proteins in animals for organizing membrane proteins. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1838:605-19. [PMID: 23747363 DOI: 10.1016/j.bbamem.2013.05.030] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 05/22/2013] [Accepted: 05/28/2013] [Indexed: 01/10/2023]
Abstract
Proteins of the 4.1 family are characteristic of eumetazoan organisms. Invertebrates contain single 4.1 genes and the Drosophila model suggests that 4.1 is essential for animal life. Vertebrates have four paralogues, known as 4.1R, 4.1N, 4.1G and 4.1B, which are additionally duplicated in the ray-finned fish. Protein 4.1R was the first to be discovered: it is a major mammalian erythrocyte cytoskeletal protein, essential to the mechanochemical properties of red cell membranes because it promotes the interaction between spectrin and actin in the membrane cytoskeleton. 4.1R also binds certain phospholipids and is required for the stable cell surface accumulation of a number of erythrocyte transmembrane proteins that span multiple functional classes; these include cell adhesion molecules, transporters and a chemokine receptor. The vertebrate 4.1 proteins are expressed in most tissues, and they are required for the correct cell surface accumulation of a very wide variety of membrane proteins including G-Protein coupled receptors, voltage-gated and ligand-gated channels, as well as the classes identified in erythrocytes. Indeed, such large numbers of protein interactions have been mapped for mammalian 4.1 proteins, most especially 4.1R, that it appears that they can act as hubs for membrane protein organization. The range of critical interactions of 4.1 proteins is reflected in disease relationships that include hereditary anaemias, tumour suppression, control of heartbeat and nervous system function. The 4.1 proteins are defined by their domain structure: apart from the spectrin/actin-binding domain they have FERM and FERM-adjacent domains and a unique C-terminal domain. Both the FERM and C-terminal domains can bind transmembrane proteins, thus they have the potential to be cross-linkers for membrane proteins. The activity of the FERM domain is subject to multiple modes of regulation via binding of regulatory ligands, phosphorylation of the FERM associated domain and differential mRNA splicing. Finally, the spectrum of interactions of the 4.1 proteins overlaps with that of another membrane-cytoskeleton linker, ankyrin. Both ankyrin and 4.1 link to the actin cytoskeleton via spectrin, and we hypothesize that differential regulation of 4.1 proteins and ankyrins allows highly selective control of cell surface protein accumulation and, hence, function. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. Guest Editor: Jean Claude Hervé
Collapse
Affiliation(s)
| | - Hui-Chun Lu
- Randall Division of Cell and Molecular Biophysics, King's College London, UK
| | - Pauline M Bennett
- Randall Division of Cell and Molecular Biophysics, King's College London, UK.
| |
Collapse
|
24
|
Zhuravleva ZN, Zhuravlev GI, Hutsyan SS. Inductive role of mossy fibers of hippocampus in the development of dendritic spines in aberrant synaptogenesis at neurotransplantation. Russ J Dev Biol 2014. [DOI: 10.1134/s106236041401007x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
25
|
Moiseeva EP, Straatman KR, Leyland ML, Bradding P. CADM1 controls actin cytoskeleton assembly and regulates extracellular matrix adhesion in human mast cells. PLoS One 2014; 9:e85980. [PMID: 24465823 PMCID: PMC3899107 DOI: 10.1371/journal.pone.0085980] [Citation(s) in RCA: 23] [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: 10/09/2013] [Accepted: 12/03/2013] [Indexed: 12/21/2022] Open
Abstract
CADM1 is a major receptor for the adhesion of mast cells (MCs) to fibroblasts, human airway smooth muscle cells (HASMCs) and neurons. It also regulates E-cadherin and alpha6beta4 integrin in other cell types. Here we investigated a role for CADM1 in MC adhesion to both cells and extracellular matrix (ECM). Downregulation of CADM1 in the human MC line HMC-1 resulted not only in reduced adhesion to HASMCs, but also reduced adhesion to their ECM. Time-course studies in the presence of EDTA to inhibit integrins demonstrated that CADM1 provided fast initial adhesion to HASMCs and assisted with slower adhesion to ECM. CADM1 downregulation, but not antibody-dependent CADM1 inhibition, reduced MC adhesion to ECM, suggesting indirect regulation of ECM adhesion. To investigate potential mechanisms, phosphotyrosine signalling and polymerisation of actin filaments, essential for integrin-mediated adhesion, were examined. Modulation of CADM1 expression positively correlated with surface KIT levels and polymerisation of cortical F-actin in HMC-1 cells. It also influenced phosphotyrosine signalling and KIT tyrosine autophosphorylation. CADM1 accounted for 46% of surface KIT levels and 31% of F-actin in HMC-1 cells. CADM1 downregulation resulted in elongation of cortical actin filaments in both HMC-1 cells and human lung MCs and increased cell rigidity of HMC-1 cells. Collectively these data suggest that CADM1 is a key adhesion receptor, which regulates MC net adhesion, both directly through CADM1-dependent adhesion, and indirectly through the regulation of other adhesion receptors. The latter is likely to occur via docking of KIT and polymerisation of cortical F-actin. Here we propose a stepwise model of adhesion with CADM1 as a driving force for net MC adhesion.
Collapse
Affiliation(s)
- Elena P. Moiseeva
- Institute for Lung Health, Dept. of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
- * E-mail:
| | - Kees R. Straatman
- Centre for Core Biotechnology Services, University of Leicester, Leicester, United Kingdom
| | - Mark L. Leyland
- Department of Biochemistry, University of Leicester, Leicester, United Kingdom
| | - Peter Bradding
- Institute for Lung Health, Dept. of Infection, Immunity and Inflammation, University of Leicester, Leicester, United Kingdom
| |
Collapse
|
26
|
Mori M, Rikitake Y, Mandai K, Takai Y. Roles of Nectins and Nectin-Like Molecules in the Nervous System. ADVANCES IN NEUROBIOLOGY 2014; 8:91-116. [DOI: 10.1007/978-1-4614-8090-7_5] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
|
27
|
Easley-Neal C, Fierro J, Buchanan J, Washbourne P. Late recruitment of synapsin to nascent synapses is regulated by Cdk5. Cell Rep 2013; 3:1199-212. [PMID: 23602570 DOI: 10.1016/j.celrep.2013.03.031] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 03/05/2013] [Accepted: 03/20/2013] [Indexed: 11/17/2022] Open
Abstract
Synapse formation is a complex process that involves the recruitment and assembly of a myriad of pre- and postsynaptic proteins. Despite being present at every synapse in the vertebrate CNS, little is known about the transport, recruitment, and stabilization of synapsin at nascent synapses during development. We examined the transport and recruitment of synapsin to nascent presynaptic terminals in vivo in the developing zebrafish spinal cord. Synapsin was transported in a transport packet independently of two other presynaptic organelles: synaptic vesicle (SV) protein transport vesicles (STVs) and Piccolo-containing active zone precursor transport vesicles (PTVs). During presynaptic assembly, recruitment of all three transport packets occurred in an ordered sequence: STVs preceded PTVs, which in turn preceded synapsin. Importantly, cyclin-dependent kinase 5 (Cdk5) specifically regulated the late recruitment of synapsin transport packets at synapses. These results point to additional layers of complexity in the established mechanisms of synaptogenesis.
Collapse
|
28
|
The linoleic acid derivative DCP-LA increases membrane surface localization of the α7 ACh receptor in a protein 4.1N-dependent manner. Biochem J 2013; 450:303-9. [DOI: 10.1042/bj20121348] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
In yeast two-hybrid screening, protein 4.1N, a scaffolding protein, was identified as a binding partner of the α7 ACh (acetylcholine) receptor. For rat hippocampal slices, the linoleic acid derivative DCP-LA {8-[2-(2-pentyl-cyclopropylmethyl)-cyclopropyl]-octanoic acid} increased the association of the α7 ACh receptor with 4.1N, and the effect was inhibited by GF109203X, an inhibitor of PKC (protein kinase C), although DCP-LA did not induce PKC phosphorylation of 4.1N. For PC-12 cells, the presence of the α7 ACh receptor in the plasma membrane fraction was significantly suppressed by knocking down 4.1N. DCP-LA increased the presence of the α7 ACh receptor in the plasma membrane fraction, and the effect was still inhibited by knocking down 4.1N. In the monitoring of α7 ACh receptor mobilization, DCP-LA enhanced signal intensities for the α7 ACh receptor at the membrane surface in PC-12 cells, which was clearly prevented by knocking down 4.1N. Taken together, the results of the present study show that 4.1N interacts with the α7 ACh receptor and participates in the receptor tethering to the plasma membrane. The results also indicate that DCP-LA increases membrane surface localization of the α7 ACh receptor in a 4.1N-dependent manner under the control of PKC, but without phosphorylating 4.1N.
Collapse
|
29
|
Einheber S, Meng X, Rubin M, Lam I, Mohandas N, An X, Shrager P, Kissil J, Maurel P, Salzer JL. The 4.1B cytoskeletal protein regulates the domain organization and sheath thickness of myelinated axons. Glia 2012; 61:240-53. [PMID: 23109359 DOI: 10.1002/glia.22430] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 09/10/2012] [Indexed: 12/13/2022]
Abstract
Myelinated axons are organized into specialized domains critical to their function in saltatory conduction, i.e., nodes, paranodes, juxtaparanodes, and internodes. Here, we describe the distribution and role of the 4.1B protein in this organization. 4.1B is expressed by neurons, and at lower levels by Schwann cells, which also robustly express 4.1G. Immunofluorescence and immuno-EM demonstrates 4.1B is expressed subjacent to the axon membrane in all domains except the nodes. Mice deficient in 4.1B have preserved paranodes, based on marker staining and EM in contrast to the juxtaparanodes, which are substantially affected in both the PNS and CNS. The juxtaparanodal defect is evident in developing and adult nerves and is neuron-autonomous based on myelinating cocultures in which wt Schwann cells were grown with 4.1B-deficient neurons. Despite the juxtaparanodal defect, nerve conduction velocity is unaffected. Preservation of paranodal markers in 4.1B deficient mice is associated with, but not dependent on an increase of 4.1R at the axonal paranodes. Loss of 4.1B in the axon is also associated with reduced levels of the internodal proteins, Necl-1 and Necl-2, and of alpha-2 spectrin. Mutant nerves are modestly hypermyelinated and have increased numbers of Schmidt-Lanterman incisures, increased expression of 4.1G, and express a residual, truncated isoform of 4.1B. These results demonstrate that 4.1B is a key cytoskeletal scaffold for axonal adhesion molecules expressed in the juxtaparanodal and internodal domains that unexpectedly regulates myelin sheath thickness.
Collapse
Affiliation(s)
- Steven Einheber
- School of Health Sciences, Hunter College, City University of New York, New York, New York, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
30
|
Sandau US, Alderman Z, Corfas G, Ojeda SR, Raber J. Astrocyte-specific disruption of SynCAM1 signaling results in ADHD-like behavioral manifestations. PLoS One 2012; 7:e36424. [PMID: 22558465 PMCID: PMC3340339 DOI: 10.1371/journal.pone.0036424] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Accepted: 04/02/2012] [Indexed: 11/18/2022] Open
Abstract
SynCAM1 is an adhesion molecule involved in synaptic differentiation and organization. SynCAM1 is also expressed in astroglial cells where it mediates astrocyte-to astrocyte and glial-neuronal adhesive communication. In astrocytes, SynCAM1 is functionally linked to erbB4 receptors, which are involved in the control of both neuronal/glial development and mature neuronal and glial function. Here we report that mice carrying a dominant-negative form of SynCAM1 specifically targeted to astrocytes (termed GFAP-DNSynCAM1 mice) exhibit disrupted diurnal locomotor activity with enhanced and more frequent episodes of activity than control littermates during the day (when the animals are normally sleeping) accompanied by shorter periods of rest. GFAP-DNSynCAM1 mice also display high levels of basal activity in the dark period (the rodent's awake/active time) that are attenuated by the psychostimulant D,L-amphetamine, and reduced anxiety levels in response to both avoidable and unavoidable provoking stimuli. These results indicate that disruption of SynCAM1-dependent astroglial function results in behavioral abnormalities similar to those described in animals model of attention-deficit hyperactive disorder (ADHD), and suggest a hitherto unappreciated contribution of glial cells to the pathophysiology of this disorder.
Collapse
Affiliation(s)
- Ursula S. Sandau
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, United States of America
| | - Zefora Alderman
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, United States of America
| | - Gabriel Corfas
- F. M. Kirby Neurobiology Program, Harvard Medical School, Children's Hospital, Boston, Massachusetts, United States of America
| | - Sergio R. Ojeda
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, United States of America
- * E-mail: (SRO); (JR)
| | - Jacob Raber
- Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, Oregon, United States of America
- Departments of Behavioral Neurosciences and Neurology, Oregon Health & Science University, Portland, Oregon, United States of America
- * E-mail: (SRO); (JR)
| |
Collapse
|
31
|
Burton SD, Johnson JW, Zeringue HC, Meriney SD. Distinct roles of neuroligin-1 and SynCAM1 in synapse formation and function in primary hippocampal neuronal cultures. Neuroscience 2012; 215:1-16. [PMID: 22542674 DOI: 10.1016/j.neuroscience.2012.04.047] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Revised: 04/02/2012] [Accepted: 04/18/2012] [Indexed: 12/16/2022]
Abstract
Neuroligins are a family of cell adhesion molecules critical in establishing proper central nervous system connectivity; disruption of neuroligin signaling in vivo precipitates a broad range of cognitive deficits. Despite considerable recent progress, the specific synaptic function of neuroligin-1 (NL1) remains unclear. A current model proposes that NL1 acts exclusively to mature pre-existent synaptic connections in an activity-dependent manner. A second element of this activity-dependent maturation model is that an alternate molecule acts upstream of NL1 to initiate synaptic connections. SynCAM1 (SC1) is hypothesized to function in this capacity, though several uncertainties remain regarding SC1 function. Using overexpression and chronic pharmacological blockade of synaptic activity, we now demonstrate that NL1 is capable of robustly recruiting synapsin-positive terminals independent of synaptic maturation and activity in 2-week old primary hippocampal neuronal cultures. We further report that neither SC1 overexpression nor knockdown of endogenous SC1 impacts synapsin punctum densities, suggesting that SC1 is not a limiting factor of synapse initiation in maturing hippocampal neurons in vitro. Consistent with these findings, we observed profoundly greater recruitment of synapsin-positive presynaptic terminals by NL1 than SC1 in a mixed-culture assay of artificial synaptogenesis between primary neurons and heterologous cells. Collectively, our results contend multiple aspects of the proposed model of NL1 and SC1 function and motivate an alternative model whereby SC1 may mature synaptic connections forged by NL1. Supporting this model, we present evidence that combined NL1 and SC1 overexpression triggers excitotoxic neurodegeneration through SC1 signaling at synaptic connections initiated by NL1.
Collapse
Affiliation(s)
- S D Burton
- Department of Bioengineering, University of Pittsburgh, Pittsburgh, PA 15260, USA.
| | | | | | | |
Collapse
|
32
|
Deep intron elements mediate nested splicing events at consecutive AG dinucleotides to regulate alternative 3' splice site choice in vertebrate 4.1 genes. Mol Cell Biol 2012; 32:2044-53. [PMID: 22473990 DOI: 10.1128/mcb.05716-11] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Distal intraexon (iE) regulatory elements in 4.1R pre-mRNA govern 3' splice site choice at exon 2 (E2) via nested splicing events, ultimately modulating expression of N-terminal isoforms of cytoskeletal 4.1R protein. Here we explored intrasplicing in other normal and disease gene contexts and found conservation of intrasplicing through vertebrate evolution. In the paralogous 4.1B gene, we identified ∼120 kb upstream of E2 an ultradistal intraexon, iE(B), that mediates intrasplicing by promoting two intricately coupled splicing events that ensure selection of a weak distal acceptor at E2 (E2dis) by prior excision of the competing proximal acceptor (E2prox). Mutating iE(B) in minigene splicing reporters abrogated intrasplicing, as did blocking endogenous iE(B) function with antisense morpholinos in live mouse and zebrafish animal models. In a human elliptocytosis patient with a mutant 4.1R gene lacking E2 through E4, we showed that aberrant splicing is consistent with iE(R)-mediated intrasplicing at the first available exons downstream of iE(R), namely, alternative E5 and constitutive E6. Finally, analysis of heterologous acceptor contexts revealed a strong preference for nested 3' splice events at consecutive pairs of AG dinucleotides. Distal regulatory elements may control intrasplicing at a subset of alternative 3' splice sites in vertebrate pre-mRNAs to generate proteins with functional diversity.
Collapse
|
33
|
Ivanovic A, Horresh I, Golan N, Spiegel I, Sabanay H, Frechter S, Ohno S, Terada N, Möbius W, Rosenbluth J, Brose N, Peles E. The cytoskeletal adapter protein 4.1G organizes the internodes in peripheral myelinated nerves. ACTA ACUST UNITED AC 2012; 196:337-44. [PMID: 22291039 PMCID: PMC3275379 DOI: 10.1083/jcb.201111127] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Deletion of the Schwann cell cytoskeletal adapter protein 4.1G led to aberrant distribution of glial adhesion molecules and axonal proteins along the internodes. Myelinating Schwann cells regulate the localization of ion channels on the surface of the axons they ensheath. This function depends on adhesion complexes that are positioned at specific membrane domains along the myelin unit. Here we show that the precise localization of internodal proteins depends on the expression of the cytoskeletal adapter protein 4.1G in Schwann cells. Deletion of 4.1G in mice resulted in aberrant distribution of both glial adhesion molecules and axonal proteins that were present along the internodes. In wild-type nerves, juxtaparanodal proteins (i.e., Kv1 channels, Caspr2, and TAG-1) were concentrated throughout the internodes in a double strand that flanked paranodal junction components (i.e., Caspr, contactin, and NF155), and apposes the inner mesaxon of the myelin sheath. In contrast, in 4.1G−/− mice, these proteins “piled up” at the juxtaparanodal region or aggregated along the internodes. These findings suggest that protein 4.1G contributes to the organization of the internodal axolemma by targeting and/or maintaining glial transmembrane proteins along the axoglial interface.
Collapse
Affiliation(s)
- Aleksandra Ivanovic
- Department of Molecular Neurobiology and 2 Department of Neurogenetics, Max Planck Institute of Experimental Medicine, D-37075 Göttingen, Germany
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
34
|
Bukalo O, Dityatev A. Synaptic Cell Adhesion Molecules. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 970:97-128. [DOI: 10.1007/978-3-7091-0932-8_5] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
|
35
|
Nanavati D, Austin DR, Catapano LA, Luckenbaugh DA, Dosemeci A, Manji HK, Chen G, Markey SP. The effects of chronic treatment with mood stabilizers on the rat hippocampal post-synaptic density proteome. J Neurochem 2011; 119:617-29. [PMID: 21838781 DOI: 10.1111/j.1471-4159.2011.07424.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Bipolar disorder is a devastating illness that is marked by recurrent episodes of mania and depression. There is growing evidence that the disease is correlated with disruptions in synaptic plasticity cascades involved in cognition and mood regulation. Alleviating the symptoms of bipolar disorder involves chronic treatment with mood stabilizers like lithium or valproate. These two structurally dissimilar drugs are known to alter prominent signaling cascades in the hippocampus, but their effects on the post-synaptic density complex remain undefined. In this work, we utilized mass spectrometry for quantitative profiling of the rat hippocampal post-synaptic proteome to investigate the effects of chronic mood stabilizer treatment. Our data show that in response to chronic treatment of mood stabilizers there were not gross qualitative changes but rather subtle quantitative perturbations in post-synaptic density proteome linked to several key signaling pathways. Our data specifically support the changes in actin dynamics on valproate treatment. Using label-free quantification methods, we report that lithium and valproate significantly altered the abundance of 21 and 43 proteins, respectively. Seven proteins were affected similarly by both lithium and valproate: Ank3, glutamate receptor 3, dynein heavy chain 1, and four isoforms of the 14-3-3 family. Immunoblotting the same samples confirmed the changes in Ank3 and glutamate receptor 3 abundance. Our findings support the hypotheses that BPD is a synaptic disorder and that mood stabilizers modulate the protein signaling complex in the hippocampal post-synaptic density.
Collapse
Affiliation(s)
- Dhaval Nanavati
- Laboratory of Neurotoxicology, Mood and Anxiety Disorders Program, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892-1262, USA
| | | | | | | | | | | | | | | |
Collapse
|
36
|
Sandau US, Mungenast AE, Alderman Z, Sardi SP, Fogel AI, Taylor B, Parent AS, Biederer T, Corfas G, Ojeda SR. SynCAM1, a synaptic adhesion molecule, is expressed in astrocytes and contributes to erbB4 receptor-mediated control of female sexual development. Endocrinology 2011; 152:2364-76. [PMID: 21486934 PMCID: PMC3100629 DOI: 10.1210/en.2010-1435] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Female sexual maturation requires erythroblastosis B (erbB)4 signaling in hypothalamic astrocytes; however, the mechanisms by which erbB4 contributes to this process are incompletely understood. Here we show that SynCAM1, a synaptic adhesion molecule with signaling capabilities, is not only expressed highly in neurons, but also in hypothalamic astrocytes and is functionally associated with erbB4 receptor activity. Whereas SynCAM1 expression is diminished in astrocytes with impaired erbB4 signaling, ligand-dependent activation of astroglial erbB4 receptors results in rapid association of erbB4 with SynCAM1 and activation of SynCAM1 gene transcription. To determine whether astrocytic SynCAM1-dependent intracellular signaling is required for normal female reproductive function, we generated transgenic mice that express in an astrocyte-specific manner a dominant-negative form of SynCAM1 lacking the intracellular domain. The mutant protein was correctly targeted to the cell membrane and was functionally viable as shown by its ability to block intracellular calcium/calmodulin-dependent serine protein kinase redistribution, a major SynCAM1-mediated event. Dominant-negative-SynCAM1 female mice had a delayed onset of puberty, disrupted estrous cyclicity, and reduced fecundity. These deficits were associated with a reduced capacity of neuregulin-dependent erbB4 receptor activation to elicit prostaglandin E2 release from astrocytes and GnRH release from the hypothalamus. We conclude that one of the mechanisms underlying erbB4 receptor-mediated facilitation of glial-neuronal interactions in the neuroendocrine brain involves SynCAM1-dependent signaling and that this interaction is required for normal female reproductive function.
Collapse
Affiliation(s)
- Ursula S Sandau
- Division of Neuroscience, Oregon National Primate Research Center, Beaverton, Oregon 97006, USA
| | | | | | | | | | | | | | | | | | | |
Collapse
|
37
|
Choi B, Kang J, Park YS, Lee J, Cho NJ. A possible role for FRM-1, a C. elegans FERM family protein, in embryonic development. Mol Cells 2011; 31:455-9. [PMID: 21448586 PMCID: PMC3887609 DOI: 10.1007/s10059-011-0323-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2010] [Revised: 03/09/2011] [Accepted: 03/10/2011] [Indexed: 10/18/2022] Open
Abstract
FRM-1 is a member of the FERM protein superfamily containing a FERM domain, which is a highly conserved protein-protein interaction module found in most eukaryotes. Although FRM-1 is thought to be involved in linking intracellular proteins to membrane proteins, the specific role for FRM-1 remains to be elucidated. In an effort to explore the biological function of FRM-1, we examined the phenotype of frm-1(tm4168) mutant worms. We observed that frm-1(tm4168) worms have a delayed hatching phenotype. Twelve hours after being laid, when virtually all wild-type eggs had hatched, only 64% of frm-1(tm4168) eggs had hatched. About 3% of frm-1(tm4168) eggs failed to hatch, even 3 days after they had been laid. We also found that frm-1(tm4168) mutants displayed a temperature-sensitive sterility phenotype. About 13% of frm-1(tm4168) worms were unable to produce eggs or produced nonviable eggs at 25°C. In contrast, less than 1% of wild-type animals were sterile at this temperature. At 20°C, neither the mutant nor wild type appeared to be sterile. Western blot analysis indicates that FRM-1 is expressed throughout the developmental stages with the strongest expression at the egg stage. Immunostaining experiments revealed that FRM-1 is mainly localized to the plasma membrane of most if not all cells at an early embryonic stage and to the plasma membrane of P cells during the late embryonic stages. GFP fusion experiments showed that FRM-1 can be expressed in the pharynx and intestine at the larval and adult stages. Our data suggest that FRM-1 may participate in diverse biological processes, including embryonic development.
Collapse
Affiliation(s)
- Boram Choi
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju 361-763, Korea
| | - Junsu Kang
- Research Center for Functional Cellulomics, Institute of Molecular Biology and Genetics, School of Biological Sciences, Seoul National University, Seoul 151-747, Korea
| | - Yang-Seo Park
- Biotechnology Research Institute, Chungbuk National University, Cheongju 361-763, Korea
| | - Junho Lee
- Research Center for Functional Cellulomics, Institute of Molecular Biology and Genetics, School of Biological Sciences, Seoul National University, Seoul 151-747, Korea
| | - Nam Jeong Cho
- Department of Biochemistry, College of Natural Sciences, Chungbuk National University, Cheongju 361-763, Korea
- Biotechnology Research Institute, Chungbuk National University, Cheongju 361-763, Korea
| |
Collapse
|
38
|
Abstract
Recent studies have identified the leucine rich repeat protein LRRTM2 as a post-synaptic ligand of Neurexins. Neurexins also bind the post-synaptic adhesion molecules, Neuroligins. All three families of genes have been implicated in the etiologies of neurodevelopmental disorders, specifically autism spectrum disorders and schizophrenia. Does the binding promiscuity of Neurexins now suggest complex cooperativity or redundancy at the synapse? While recent studies in primary neuronal cultures and also systematic extracellular protein interaction screens suggest summative effects of these systems, we propose that studying these interactions in the developing zebrafish embryo or larvae may shed more light on their functions during synaptogenesis in vivo. These gene families have recently been extensively characterized in zebrafish, demonstrating high sequence conservation with the human genes. The simpler circuitry of the zebrafish, together with the characterization of the expression patterns down to single, identifiable neurons and the ability to knock-down or over-express multiple genes in a rapid way lend themselves to dissecting complex interaction pathways. Furthermore, the capability of performing high-throughput drug screens suggests that these small vertebrates may prove extremely useful in identifying pharmacological approaches to treating autism spectrum disorders.
Collapse
|
39
|
Tallafuss A, Constable JRL, Washbourne P. Organization of central synapses by adhesion molecules. Eur J Neurosci 2010; 32:198-206. [PMID: 20646051 DOI: 10.1111/j.1460-9568.2010.07340.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Synapses are the primary means for transmitting information from one neuron to the next. They are formed during the development of the nervous system, and the formation of appropriate synapses is crucial for the establishment of neuronal circuits that underlie behavior and cognition. Understanding how synapses form and are maintained will allow us to address developmental disorders such as autism, mental retardation and possibly also psychological disorders. A number of biochemical and proteomic studies have revealed a diverse and vast assortment of molecules that are present at the synapse. It is now important to untangle this large array of proteins and determine how it assembles into a functioning unit. Here we focus on recent reports describing how synaptic cell adhesion molecules interact with and organize the presynaptic and postsynaptic specializations of both excitatory and inhibitory central synapses.
Collapse
|
40
|
SynCAM 1 participates in axo-dendritic contact assembly and shapes neuronal growth cones. Proc Natl Acad Sci U S A 2010; 107:7568-73. [PMID: 20368431 DOI: 10.1073/pnas.0911798107] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Neuronal growth cones are highly motile structures that tip developing neurites and explore their surroundings before axo-dendritic contact and synaptogenesis. However, the membrane proteins organizing these processes remain insufficiently understood. Here we identify that the synaptic cell adhesion molecule 1 (SynCAM 1), an immunoglobulin superfamily member, is already expressed in developing neurons and localizes to their growth cones. Upon interaction of growth cones with target neurites, SynCAM 1 rapidly assembles at these contacts to form stable adhesive clusters. Synaptic markers can also be detected at these sites. Addressing the functions of SynCAM 1 in growth cones preceding contact, we determine that it is required and sufficient to restrict the number of active filopodia. Further, SynCAM 1 negatively regulates the morphological complexity of migrating growth cones. Focal adhesion kinase, a binding partner of SynCAM 1, is implicated in its morphogenetic activities. These results reveal that SynCAM 1 acts in developing neurons to shape migrating growth cones and contributes to the adhesive differentiation of their axo-dendritic contacts.
Collapse
|
41
|
Organization of myelinated axons by Caspr and Caspr2 requires the cytoskeletal adapter protein 4.1B. J Neurosci 2010; 30:2480-9. [PMID: 20164332 DOI: 10.1523/jneurosci.5225-09.2010] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Caspr and Caspr2 regulate the formation of distinct axonal domains around the nodes of Ranvier. Caspr is required for the generation of a membrane barrier at the paranodal junction (PNJ), whereas Caspr2 serves as a membrane scaffold that clusters Kv1 channels at the juxtaparanodal region (JXP). Both Caspr and Caspr2 interact with protein 4.1B, which may link the paranodal and juxtaparanodal adhesion complexes to the axonal cytoskeleton. To determine the role of protein 4.1B in the function of Caspr proteins, we examined the ability of transgenic Caspr and Caspr2 mutants lacking their 4.1-binding sequence (d4.1) to restore Kv1 channel clustering in Caspr- and Caspr2-null mice, respectively. We found that Caspr-d4.1 was localized to the PNJ and is able to recruit the paranodal adhesion complex components contactin and NF155 to this site. Nevertheless, in axons expressing Caspr-d4.1, Kv1 channels were often detected at paranodes, suggesting that the interaction of Caspr with protein 4.1B is necessary for the generation of an efficient membrane barrier at the PNJ. We also found that the Caspr2-d4.1 transgene did not accumulate at the JXP, even though it was targeted to the axon, demonstrating that the interaction with protein 4.1B is required for the accumulation of Caspr2 and Kv1 channels at the juxtaparanodal axonal membrane. In accordance, we show that Caspr2 and Kv1 channels are not clustered at the JXP in 4.1B-null mice. Our results thus underscore the functional importance of protein 4.1B in the organization of peripheral myelinated axons.
Collapse
|