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Ojima D, Tominaga Y, Kubota T, Tada A, Takahashi H, Kishimoto Y, Tominaga T, Yamamoto T. Impaired Hippocampal Long-Term Potentiation and Memory Deficits upon Haploinsufficiency of MDGA1 Can Be Rescued by Acute Administration of D-Cycloserine. Int J Mol Sci 2024; 25:9674. [PMID: 39273620 DOI: 10.3390/ijms25179674] [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: 08/08/2024] [Revised: 08/30/2024] [Accepted: 09/04/2024] [Indexed: 09/15/2024] Open
Abstract
The maintenance of proper brain function relies heavily on the balance of excitatory and inhibitory neural circuits, governed in part by synaptic adhesion molecules. Among these, MDGA1 (MAM domain-containing glycosylphosphatidylinositol anchor 1) acts as a suppressor of synapse formation by interfering with Neuroligin-mediated interactions, crucial for maintaining the excitatory-inhibitory (E/I) balance. Mdga1-/- mice exhibit selectively enhanced inhibitory synapse formation in their hippocampal pyramidal neurons, leading to impaired hippocampal long-term potentiation (LTP) and hippocampus-dependent learning and memory function; however, it has not been fully investigated yet if the reduction in MDGA1 protein levels would alter brain function. Here, we examined the behavioral and synaptic consequences of reduced MDGA1 protein levels in Mdga1+/- mice. As observed in Mdga1-/- mice, Mdga1+/- mice exhibited significant deficits in hippocampus-dependent learning and memory tasks, such as the Morris water maze and contextual fear-conditioning tests, along with a significant deficit in the long-term potentiation (LTP) in hippocampal Schaffer collateral CA1 synapses. The acute administration of D-cycloserine, a co-agonist of NMDAR (N-methyl-d-aspartate receptor), significantly ameliorated memory impairments and restored LTP deficits specifically in Mdga1+/- mice, while having no such effect on Mdga1-/- mice. These results highlight the critical role of MDGA1 in regulating inhibitory synapse formation and maintaining the E/I balance for proper cognitive function. These findings may also suggest potential therapeutic strategies targeting the E/I imbalance to alleviate cognitive deficits associated with neuropsychiatric disorders.
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Grants
- 16K08237, 19K07065, 19K07337, 16H06532, 24H01497, 23K18485, 23K21755, 21H03606, 23H03488, 23K28178, 23K21713, 22H05698, 24K18267, 21K15247, 19K07337, 22K06618 the Ministry of Education, Culture, Sports, Science and Technology, Japan
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Affiliation(s)
- Daiki Ojima
- Department of Molecular Neurobiology, Faculty of Medicine, Kagawa University, Miki-cho 761-0793, Kagawa, Japan
| | - Yoko Tominaga
- Institute of Neuroscience, Tokushima Bunri University, Sanuki 769-2193, Kagawa, Japan
| | - Takashi Kubota
- Department of Neurobiophysics, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Kagawa, Japan
| | - Atsushi Tada
- Department of Molecular Neurobiology, Faculty of Medicine, Kagawa University, Miki-cho 761-0793, Kagawa, Japan
| | - Hiroo Takahashi
- Department of Molecular Neurobiology, Faculty of Medicine, Kagawa University, Miki-cho 761-0793, Kagawa, Japan
| | - Yasushi Kishimoto
- Department of Neurobiophysics, Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Kagawa, Japan
- Laboratory of Physical Chemistry, Faculty of Pharmaceutical Sciences, Teikyo University, Itabashi-ku 173-8605, Tokyo, Japan
| | - Takashi Tominaga
- Institute of Neuroscience, Tokushima Bunri University, Sanuki 769-2193, Kagawa, Japan
- Kagawa School of Pharmaceutical Sciences, Tokushima Bunri University, Sanuki 769-2193, Kagawa, Japan
| | - Tohru Yamamoto
- Department of Molecular Neurobiology, Faculty of Medicine, Kagawa University, Miki-cho 761-0793, Kagawa, Japan
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2
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Imamura I, Kiyama R. Potential involvement of KANK1 haploinsufficiency in centrosome aberrations. Biochim Biophys Acta Gen Subj 2024; 1868:130648. [PMID: 38830559 DOI: 10.1016/j.bbagen.2024.130648] [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: 12/21/2023] [Revised: 05/04/2024] [Accepted: 05/24/2024] [Indexed: 06/05/2024]
Abstract
KANK1 was found as a tumor suppressor gene based on frequent deletions in renal cell carcinoma and the inhibitory activity of tumor cell proliferation. Previously, we reported that knockdown of KANK1 induced centrosomal amplification, leading to abnormal cell division, through the hyperactivation of RhoA small GTPase. Here, we investigated the loss of KANK1 function by performing CRISPR/Cas9-based genome editing to knockout the gene. After several rounds of genome editing, however, there were no cell lines with complete loss of KANK1, and the less the wild-type KANK1 dosage, the greater the number of cells with abnormal numbers of centrosomes and rates of cell-doubling and apoptosis, suggesting the involvement of KANK1 haploinsufficiency in centrosome aberrations. The rescue of KANK1-knockdown cells with a KANK1-expressing plasmid restored the rates of cells exhibiting centrosomal amplification to the control level. RNA-sequencing analysis of the cells with reduced dosages of functional KANK1 revealed potential involvement of other cell proliferation-related genes, such as EGR1, MDGA2, and BMP3, which have been reported to show haploinsufficiency when they function. When EGR1 protein expression was reduced by siRNA technology, the number of cells exhibiting centrosomal amplification increased, along with the reduction of KANK1 protein expression, suggesting their functional relationship. Thus, KANK1 haploinsufficiency may contribute to centrosome aberrations through the network of haploinsufficiency-related genes.
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Affiliation(s)
- Ikumi Imamura
- Faculty of Life Science, Kyushu Sangyo University, Japan
| | - Ryoiti Kiyama
- Faculty of Life Science, Kyushu Sangyo University, Japan.
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3
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Wang X, Lin D, Jiang J, Liu Y, Dong X, Fan J, Gong L, Shen W, Zeng L, Xu T, Jiang K, Connor SA, Xie Y. MDGA2 Constrains Glutamatergic Inputs Selectively onto CA1 Pyramidal Neurons to Optimize Neural Circuits for Plasticity, Memory, and Social Behavior. Neurosci Bull 2024; 40:887-904. [PMID: 38321347 PMCID: PMC11250762 DOI: 10.1007/s12264-023-01171-1] [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: 06/30/2023] [Accepted: 10/08/2023] [Indexed: 02/08/2024] Open
Abstract
Synapse organizers are essential for the development, transmission, and plasticity of synapses. Acting as rare synapse suppressors, the MAM domain containing glycosylphosphatidylinositol anchor (MDGA) proteins contributes to synapse organization by inhibiting the formation of the synaptogenic neuroligin-neurexin complex. A previous analysis of MDGA2 mice lacking a single copy of Mdga2 revealed upregulated glutamatergic synapses and behaviors consistent with autism. However, MDGA2 is expressed in diverse cell types and is localized to both excitatory and inhibitory synapses. Differentiating the network versus cell-specific effects of MDGA2 loss-of-function requires a cell-type and brain region-selective strategy. To address this, we generated mice harboring a conditional knockout of Mdga2 restricted to CA1 pyramidal neurons. Here we report that MDGA2 suppresses the density and function of excitatory synapses selectively on pyramidal neurons in the mature hippocampus. Conditional deletion of Mdga2 in CA1 pyramidal neurons of adult mice upregulated miniature and spontaneous excitatory postsynaptic potentials, vesicular glutamate transporter 1 intensity, and neuronal excitability. These effects were limited to glutamatergic synapses as no changes were detected in miniature and spontaneous inhibitory postsynaptic potential properties or vesicular GABA transporter intensity. Functionally, evoked basal synaptic transmission and AMPAR receptor currents were enhanced at glutamatergic inputs. At a behavioral level, memory appeared to be compromised in Mdga2 cKO mice as both novel object recognition and contextual fear conditioning performance were impaired, consistent with deficits in long-term potentiation in the CA3-CA1 pathway. Social affiliation, a behavioral analog of social deficits in autism, was similarly compromised. These results demonstrate that MDGA2 confines the properties of excitatory synapses to CA1 neurons in mature hippocampal circuits, thereby optimizing this network for plasticity, cognition, and social behaviors.
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Affiliation(s)
- Xuehui Wang
- School of Life Sciences, Nanchang University, Nanchang, 330031, China
- Department of Neurology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, China
| | - Donghui Lin
- Department of Neurology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, China
| | - Jie Jiang
- Department of Neurology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, China
- Department of Biology, York University, 4700 Keele Street, Toronto, ON, M3J 1P3, Canada
| | - Yuhua Liu
- School of Life Sciences, Nanchang University, Nanchang, 330031, China
- Department of Neurology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, China
| | - Xinyan Dong
- Department of Neurology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, China
| | - Jianchen Fan
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou, 310015, China
| | - Lifen Gong
- Department of Neurology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, China
| | - Weida Shen
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou, 310015, China
| | - Linghui Zeng
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou, 310015, China
| | - Tonghui Xu
- School of Life Sciences, Nanchang University, Nanchang, 330031, China
| | - Kewen Jiang
- Department of Neurology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, China.
| | - Steven A Connor
- Department of Biology, York University, 4700 Keele Street, Toronto, ON, M3J 1P3, Canada.
| | - Yicheng Xie
- School of Life Sciences, Nanchang University, Nanchang, 330031, China.
- Department of Neurology, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, 310052, China.
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Kim S, Jang G, Kim H, Lim D, Han KA, Um JW, Ko J. MDGAs perform activity-dependent synapse type-specific suppression via distinct extracellular mechanisms. Proc Natl Acad Sci U S A 2024; 121:e2322978121. [PMID: 38900791 PMCID: PMC11214077 DOI: 10.1073/pnas.2322978121] [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: 12/29/2023] [Accepted: 05/15/2024] [Indexed: 06/22/2024] Open
Abstract
MDGA (MAM domain containing glycosylphosphatidylinositol anchor) family proteins were previously identified as synaptic suppressive factors. However, various genetic manipulations have yielded often irreconcilable results, precluding precise evaluation of MDGA functions. Here, we found that, in cultured hippocampal neurons, conditional deletion of MDGA1 and MDGA2 causes specific alterations in synapse numbers, basal synaptic transmission, and synaptic strength at GABAergic and glutamatergic synapses, respectively. Moreover, MDGA2 deletion enhanced both N-methyl-D-aspartate (NMDA) receptor- and α-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptor-mediated postsynaptic responses. Strikingly, ablation of both MDGA1 and MDGA2 abolished the effect of deleting individual MDGAs that is abrogated by chronic blockade of synaptic activity. Molecular replacement experiments further showed that MDGA1 requires the meprin/A5 protein/PTPmu (MAM) domain, whereas MDGA2 acts via neuroligin-dependent and/or MAM domain-dependent pathways to regulate distinct postsynaptic properties. Together, our data demonstrate that MDGA paralogs act as unique negative regulators of activity-dependent postsynaptic organization at distinct synapse types, and cooperatively contribute to adjustment of excitation-inhibition balance.
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Affiliation(s)
- Seungjoon Kim
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
- Center for Synapse Diversity and Specificity, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
| | - Gyubin Jang
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
- Center for Synapse Diversity and Specificity, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
| | - Hyeonho Kim
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
- Center for Synapse Diversity and Specificity, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
| | - Dongseok Lim
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
| | - Kyung Ah Han
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
- Center for Synapse Diversity and Specificity, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
| | - Ji Won Um
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
- Center for Synapse Diversity and Specificity, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
| | - Jaewon Ko
- Department of Brain Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
- Center for Synapse Diversity and Specificity, Daegu Gyeongbuk Institute of Science and Technology, Daegu42988, Korea
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5
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Li HL, Guo RJ, Ai ZR, Han S, Guan Y, Li JF, Wang Y. Upregulation of Spinal MDGA1 in Rats After Nerve Injury Alters Interactions Between Neuroligin-2 and Postsynaptic Scaffolding Proteins and Increases GluR1 Subunit Surface Delivery in the Spinal Cord Dorsal Horn. Neurochem Res 2024; 49:507-518. [PMID: 37955815 DOI: 10.1007/s11064-023-04049-w] [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: 08/20/2023] [Revised: 10/13/2023] [Accepted: 10/17/2023] [Indexed: 11/14/2023]
Abstract
Previous studies suggested that postsynaptic neuroligin-2 may shift from inhibitory toward excitatory function under pathological pain conditions. We hypothesize that nerve injury may increase the expression of spinal MAM-domain GPI-anchored molecule 1 (MDGA1), which can bind to neuroligin-2 and thereby, alter its interactions with postsynaptic scaffolding proteins and increase spinal excitatory synaptic transmission, leading to neuropathic pain. Western blot, immunofluorescence staining, and co-immunoprecipitation studies were conducted to examine the critical role of MDGA1 in the lumbar spinal cord dorsal horn in rats after spinal nerve ligation (SNL). Small interfering ribonucleic acids (siRNAs) targeting MDGA1 were used to examine the functional roles of MDGA1 in neuropathic pain. Protein levels of MDGA1 in the ipsilateral dorsal horn were significantly upregulated at day 7 post-SNL, as compared to that in naïve or sham rats. The increased levels of GluR1 in the synaptosomal membrane fraction of the ipsilateral dorsal horn tissues at day 7 post-SNL was normalized to near sham level by pretreatment with intrathecal MDGA1 siRNA2308, but not scrambled siRNA or vehicle. Notably, knocking down MDGA1 with siRNAs reduced the mechanical and thermal pain hypersensitivities, and inhibited the increased excitatory synaptic interaction between neuroligin-2 with PSD-95, and prevented the decreased inhibitory postsynaptic interactions between neuroligin-2 and Gephyrin. Our findings suggest that SNL upregulated MDGA1 expression in the dorsal horn, which contributes to the pain hypersensitivity through increasing the net excitatory interaction mediated by neuroligin-2 and surface delivery of GluR1 subunit in dorsal horn neurons.
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Affiliation(s)
- Hui-Li Li
- Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, No. 95, Yongan Road, Xicheng District, Beijing, 100050, China
| | - Rui-Juan Guo
- Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, No. 95, Yongan Road, Xicheng District, Beijing, 100050, China
| | - Zhang-Ran Ai
- Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing, 100020, China
| | - Song Han
- Department of Neurobiology, Capital Medical University, Beijing, 100069, China
| | - Yun Guan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Jun-Fa Li
- Department of Neurobiology, Capital Medical University, Beijing, 100069, China
| | - Yun Wang
- Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, No. 95, Yongan Road, Xicheng District, Beijing, 100050, China.
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6
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Connor SA, Siddiqui TJ. Synapse organizers as molecular codes for synaptic plasticity. Trends Neurosci 2023; 46:971-985. [PMID: 37652840 DOI: 10.1016/j.tins.2023.08.001] [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: 05/21/2023] [Revised: 07/13/2023] [Accepted: 08/03/2023] [Indexed: 09/02/2023]
Abstract
Synapse organizing proteins are multifaceted molecules that coordinate the complex processes of brain development and plasticity at the level of individual synapses. Their importance is demonstrated by the major brain disorders that emerge when their function is compromised. The mechanisms whereby the various families of organizers govern synapses are diverse, but converge on the structure, function, and plasticity of synapses. Therefore, synapse organizers regulate how synapses adapt to ongoing activity, a process central for determining the developmental trajectory of the brain and critical to all forms of cognition. Here, we explore how synapse organizers set the conditions for synaptic plasticity and the associated molecular events, which eventually link to behavioral features of neurodevelopmental and neuropsychiatric disorders. We also propose central questions on how synapse organizers influence network function through integrating nanoscale and circuit-level organization of the brain.
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Affiliation(s)
- Steven A Connor
- Department of Biology, York University, Toronto, ON M3J 1P3, Canada.
| | - Tabrez J Siddiqui
- PrairieNeuro Research Centre, Kleysen Institute for Advanced Medicine, Health Sciences Centre, Winnipeg, MB R3E 0Z3, Canada; Department of Physiology and Pathophysiology, University of Manitoba, Winnipeg, MB R3E 0J9, Canada; The Children's Hospital Research Institute of Manitoba, Winnipeg, MB R3E 3P4, Canada; Program in Biomedical Engineering, University of Manitoba, Winnipeg, MB, Canada.
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7
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Ulloa Severino FP, Lawal OO, Sakers K, Wang S, Kim N, Friedman AD, Johnson SA, Sriworarat C, Hughes RH, Soderling SH, Kim IH, Yin HH, Eroglu C. Training-induced circuit-specific excitatory synaptogenesis in mice is required for effort control. Nat Commun 2023; 14:5522. [PMID: 37684234 PMCID: PMC10491649 DOI: 10.1038/s41467-023-41078-z] [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: 10/29/2022] [Accepted: 08/17/2023] [Indexed: 09/10/2023] Open
Abstract
Synaptogenesis is essential for circuit development; however, it is unknown whether it is critical for the establishment and performance of goal-directed voluntary behaviors. Here, we show that operant conditioning via lever-press for food reward training in mice induces excitatory synapse formation onto a subset of anterior cingulate cortex neurons projecting to the dorsomedial striatum (ACC→DMS). Training-induced synaptogenesis is controlled by the Gabapentin/Thrombospondin receptor α2δ-1, which is an essential neuronal protein for proper intracortical excitatory synaptogenesis. Using germline and conditional knockout mice, we found that deletion of α2δ-1 in the adult ACC→DMS circuit diminishes training-induced excitatory synaptogenesis. Surprisingly, this manipulation does not impact learning but results in a significant increase in effort exertion without affecting sensitivity to reward value or changing contingencies. Bidirectional optogenetic manipulation of ACC→DMS neurons rescues or phenocopies the behaviors of the α2δ-1 cKO mice, highlighting the importance of synaptogenesis within this cortico-striatal circuit in regulating effort exertion.
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Affiliation(s)
- Francesco Paolo Ulloa Severino
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA.
- Department of Psychology and Neuroscience, Duke University, Durham, NC, 27710, USA.
- Cajal Institute (CSIC), Madrid, 28001, Spain.
| | | | - Kristina Sakers
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Shiyi Wang
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | - Namsoo Kim
- Department of Psychology and Neuroscience, Duke University, Durham, NC, 27710, USA
| | | | - Sarah Anne Johnson
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
| | | | - Ryan H Hughes
- Department of Psychology and Neuroscience, Duke University, Durham, NC, 27710, USA
| | - Scott H Soderling
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA
- Department of Neurobiology, Duke University Medical Center, Durham, NC, 27710, USA
- Duke Institute for Brain Sciences (DIBS), Durham, NC, 27710, USA
| | - Il Hwan Kim
- Department of Anatomy & Neurobiology, University of Tennessee Health and Science Center, Memphis, TN, 38103, USA
| | - Henry H Yin
- Department of Psychology and Neuroscience, Duke University, Durham, NC, 27710, USA.
- Department of Neurobiology, Duke University Medical Center, Durham, NC, 27710, USA.
- Duke Institute for Brain Sciences (DIBS), Durham, NC, 27710, USA.
| | - Cagla Eroglu
- Department of Cell Biology, Duke University Medical Center, Durham, NC, 27710, USA.
- Department of Neurobiology, Duke University Medical Center, Durham, NC, 27710, USA.
- Duke Institute for Brain Sciences (DIBS), Durham, NC, 27710, USA.
- Howard Hughes Medical Institute, Duke University, Durham, NC, 27710, USA.
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8
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Fertan E, Wong AA, Montbrun TSGD, Purdon MK, Roddick KM, Yamamoto T, Brown RE. Early postnatal development of the MDGA2 +/- mouse model of synaptic dysfunction. Behav Brain Res 2023; 452:114590. [PMID: 37499910 DOI: 10.1016/j.bbr.2023.114590] [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: 05/05/2023] [Revised: 06/13/2023] [Accepted: 07/19/2023] [Indexed: 07/29/2023]
Abstract
Synaptic dysfunction underlies many neurodevelopmental disorders (NDDs). The membrane-associated mucin domain-containing glycosylphosphatidylinositol anchor proteins (MDGAs) regulate synaptic development by modulating neurexin-neuroligin complex formation. Since understanding the neurodevelopmental profile and the sex-based differences in the manifestation of the symptoms of NDDs is important for their early diagnosis, we tested a mouse model haploinsufficient for MDGA2 (MDGA2+/-) on a neurodevelopmental test battery, containing sensory, motor, and cognitive measures, as well as ultrasonic vocalizations. When male and female MDGA2+/- and wildtype (WT) C57BL/6 J mice were examined from 2 to 23 days of age using this test battery, genotype and sex differences in body weight, sensory-motor processes, and ultrasonic vocalizations were observed. The auditory startle reflex appeared earlier in the MDGA2+/- than in WT mice and the MDGA2+/- mice produced fewer ultrasonic vocalizations. The MDGA2+/- mice showed reduced locomotion and rearing than WT mice in the open field after 17 days of age and spent less time investigating a novel object than WT mice at 21 days of age. Female MDGA2+/- mice weighed less than WT females and showed lower grip strength, indicating a delay in sensory-motor development in MDGA2+/- mice, which appears to be more pronounced in females than males. The behavioural phenotypes resulting from MDGA2 haploinsufficiency suggests that it shows delayed development of motor behaviour, grip strength and exploratory behaviour, non-social phenotypes of NDDs.
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Affiliation(s)
- Emre Fertan
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Aimée A Wong
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | | | - Michaela K Purdon
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Kyle M Roddick
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
| | - Tohru Yamamoto
- Department of Molecular Neurobiology, Faculty of Medicine, Kagawa University, 1750-1 Ikenobe, Miki-cho, Kagawa 761-0793, Japan
| | - Richard E Brown
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada.
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9
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Bemben MA, Sandoval M, Le AA, Won S, Chau VN, Lauterborn JC, Incontro S, Li KH, Burlingame AL, Roche KW, Gall CM, Nicoll RA, Diaz-Alonso J. Contrastsing synaptic roles of MDGA1 and MDGA2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.25.542333. [PMID: 37720016 PMCID: PMC10503827 DOI: 10.1101/2023.05.25.542333] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Neurodevelopmental disorders are frequently linked to mutations in synaptic organizing molecules. MAM domain containing glycosylphosphatidylinositol anchor 1 and 2 (MDGA1 and MDGA2) are a family of synaptic organizers suggested to play an unusual role as synaptic repressors, but studies offer conflicting evidence for their localization. Using epitope-tagged MDGA1 and MDGA2 knock-in mice, we found that native MDGAs are expressed throughout the brain, peaking early in postnatal development. Surprisingly, endogenous MDGA1 was enriched at excitatory, but not inhibitory, synapses. Both shRNA knockdown and CRISPR/Cas9 knockout of MDGA1 resulted in cell-autonomous, specific impairment of AMPA receptor-mediated synaptic transmission, without affecting GABAergic transmission. Conversely, MDGA2 knockdown/knockout selectively depressed NMDA receptor-mediated transmission but enhanced inhibitory transmission. Our results establish that MDGA2 acts as a synaptic repressor, but only at inhibitory synapses, whereas both MDGAs are required for excitatory transmission. This nonoverlapping division of labor between two highly conserved synaptic proteins is unprecedented.
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Affiliation(s)
- Michael A. Bemben
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA 94158, USA
| | - Matthew Sandoval
- Department of Anatomy & Neurobiology, University of California at Irvine, CA, 92617, USA
- Center for the Neurobiology of Learning and Memory, University of California at Irvine, CA, USA
| | - Aliza A. Le
- Department of Anatomy & Neurobiology, University of California at Irvine, CA, 92617, USA
- Center for the Neurobiology of Learning and Memory, University of California at Irvine, CA, USA
| | - Sehoon Won
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, 20892, USA
| | - Vivian N. Chau
- Department of Anatomy & Neurobiology, University of California at Irvine, CA, 92617, USA
- Center for the Neurobiology of Learning and Memory, University of California at Irvine, CA, USA
| | - Julie C. Lauterborn
- Department of Anatomy & Neurobiology, University of California at Irvine, CA, 92617, USA
- Center for the Neurobiology of Learning and Memory, University of California at Irvine, CA, USA
| | - Salvatore Incontro
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA 94158, USA
- Present address: Unité de Neurobiologie des canaux Ioniques et de la Synapse (UNIS), UMR1072, INSERM, Aix-Marseille University, Marseille, 13015, France
| | - Kathy H. Li
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Alma L. Burlingame
- Department of Pharmaceutical Chemistry, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Katherine W. Roche
- Receptor Biology Section, National Institute of Neurological Disorders and Stroke (NINDS), National Institutes of Health (NIH), Bethesda, MD, 20892, USA
| | - Christine M. Gall
- Department of Anatomy & Neurobiology, University of California at Irvine, CA, 92617, USA
- Center for the Neurobiology of Learning and Memory, University of California at Irvine, CA, USA
| | - Roger A. Nicoll
- Department of Cellular and Molecular Pharmacology, University of California at San Francisco, San Francisco, CA 94158, USA
- Department of Physiology, University of California at San Francisco, San Francisco, CA, 94158, USA
| | - Javier Diaz-Alonso
- Department of Anatomy & Neurobiology, University of California at Irvine, CA, 92617, USA
- Center for the Neurobiology of Learning and Memory, University of California at Irvine, CA, USA
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10
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Golf SR, Trotter JH, Nakahara G, Südhof TC. Astrocytic Neuroligins Are Not Required for Synapse Formation or a Normal Astrocyte Cytoarchitecture. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.10.536254. [PMID: 37090508 PMCID: PMC10120619 DOI: 10.1101/2023.04.10.536254] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/25/2023]
Abstract
Astrocytes exert multifarious roles in the formation, regulation, and function of synapses in the brain, but the mechanisms involved remain unclear. Interestingly, astrocytes abundantly express neuroligins, postsynaptic adhesion molecules that bind to presynaptic neurexins. A pioneering recent study reported that loss-of-function of neuroligins in astrocytes impairs excitatory synapse formation and astrocyte morphogenesis. This study suggested a crucial synaptic function for astrocytic neuroligins but was puzzling given that constitutive neuroligin deletions do not decrease excitatory synapse numbers. Thus, we here examined the function of astrocytic neuroligins using a rigorous conditional genetic approach with deletion of all major neuroligins (Nlgn1-3) in astrocytes. Our results show that early postnatal deletion of neuroligins from astrocytes has no effect on cortical or hippocampal synapses and does not alter the cytoarchitecture of astrocytes. Thus, astrocytic neuroligins are unlikely to shape synapse formation or astrocyte development but may perform other important functions in astrocytes.
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Affiliation(s)
- Samantha R. Golf
- Dept. of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Justin H. Trotter
- Dept. of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - George Nakahara
- Dept. of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Thomas C. Südhof
- Dept. of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA 94305, USA
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11
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Lee H, Chofflet N, Liu J, Fan S, Lu Z, Resua Rojas M, Penndorf P, Bailey AO, Russell WK, Machius M, Ren G, Takahashi H, Rudenko G. Designer molecules of the synaptic organizer MDGA1 reveal 3D conformational control of biological function. J Biol Chem 2023; 299:104586. [PMID: 36889589 PMCID: PMC10131064 DOI: 10.1016/j.jbc.2023.104586] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Revised: 02/21/2023] [Accepted: 02/22/2023] [Indexed: 03/08/2023] Open
Abstract
MDGAs (MAM domain-containing glycosylphosphatidylinositol anchors) are synaptic cell surface molecules that regulate the formation of trans-synaptic bridges between neurexins (NRXNs) and neuroligins (NLGNs), which promote synaptic development. Mutations in MDGAs are implicated in various neuropsychiatric diseases. MDGAs bind NLGNs in cis on the postsynaptic membrane and physically block NLGNs from binding to NRXNs. In crystal structures, the six immunoglobulin (Ig) and single fibronectin III domains of MDGA1 reveal a striking compact, triangular shape, both alone and in complex with NLGNs. Whether this unusual domain arrangement is required for biological function or other arrangements occur with different functional outcomes is unknown. Here, we show that WT MDGA1 can adopt both compact and extended 3D conformations that bind NLGN2. Designer mutants targeting strategic molecular elbows in MDGA1 alter the distribution of 3D conformations while leaving the binding affinity between soluble ectodomains of MDGA1 and NLGN2 intact. In contrast, in a cellular context, these mutants result in unique combinations of functional consequences, including altered binding to NLGN2, decreased capacity to conceal NLGN2 from NRXN1β, and/or suppressed NLGN2-mediated inhibitory presynaptic differentiation, despite the mutations being located far from the MDGA1-NLGN2 interaction site. Thus, the 3D conformation of the entire MDGA1 ectodomain appears critical for its function, and its NLGN-binding site on Ig1-Ig2 is not independent of the rest of the molecule. As a result, global 3D conformational changes to the MDGA1 ectodomain via strategic elbows may form a molecular mechanism to regulate MDGA1 action within the synaptic cleft.
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Affiliation(s)
- Hubert Lee
- Deptartment of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
| | - Nicolas Chofflet
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montréal, Quebec, Canada; Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada
| | - Jianfang Liu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Shanghua Fan
- Deptartment of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
| | - Zhuoyang Lu
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
| | - Martin Resua Rojas
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montréal, Quebec, Canada
| | - Patrick Penndorf
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montréal, Quebec, Canada
| | - Aaron O Bailey
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - William K Russell
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX, USA
| | - Mischa Machius
- Deptartment of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA
| | - Gang Ren
- The Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, CA, USA.
| | - Hideto Takahashi
- Synapse Development and Plasticity Research Unit, Institut de Recherches Cliniques de Montréal, Montréal, Quebec, Canada; Integrated Program in Neuroscience, McGill University, Montreal, Quebec, Canada; Department of Medicine, Université de Montréal, Montréal, Quebec, Canada; Division of Experimental Medicine, McGill University, Montréal, Quebec, Canada.
| | - Gabby Rudenko
- Deptartment of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX, USA.
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12
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Li H, Guo R, Guan Y, Li J, Wang Y. Modulation of Trans-Synaptic Neurexin-Neuroligin Interaction in Pathological Pain. Cells 2022; 11:cells11121940. [PMID: 35741069 PMCID: PMC9222181 DOI: 10.3390/cells11121940] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Revised: 06/13/2022] [Accepted: 06/15/2022] [Indexed: 11/16/2022] Open
Abstract
Synapses serve as the interface for the transmission of information between neurons in the central nervous system. The structural and functional characteristics of synapses are highly dynamic, exhibiting extensive plasticity that is shaped by neural activity and regulated primarily by trans-synaptic cell-adhesion molecules (CAMs). Prototypical trans-synaptic CAMs, such as neurexins (Nrxs) and neuroligins (Nlgs), directly regulate the assembly of presynaptic and postsynaptic molecules, including synaptic vesicles, active zone proteins, and receptors. Therefore, the trans-synaptic adhesion mechanisms mediated by Nrx-Nlg interaction can contribute to a range of synaptopathies in the context of pathological pain and other neurological disorders. The present review provides an overview of the current understanding of the roles of Nrx-Nlg interaction in the regulation of trans-synaptic connections, with a specific focus on Nrx and Nlg structures, the dynamic shaping of synaptic function, and the dysregulation of Nrx-Nlg in pathological pain. Additionally, we discuss a range of proteins capable of modulating Nrx-Nlg interactions at the synaptic cleft, with the objective of providing a foundation to guide the future development of novel therapeutic agents for managing pathological pain.
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Affiliation(s)
- Huili Li
- Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China;
| | - Ruijuan Guo
- Department of Anesthesiology, Beijing Friendship Hospital, Capital Medical University, Beijing 100030, China;
| | - Yun Guan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA;
| | - Junfa Li
- Department of Neurobiology, Capital Medical University, Beijing 100069, China;
| | - Yun Wang
- Department of Anesthesiology, Beijing Chaoyang Hospital, Capital Medical University, Beijing 100020, China;
- Correspondence: ; Tel.: +86-10-85231463
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13
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Toledo A, Letellier M, Bimbi G, Tessier B, Daburon S, Favereaux A, Chamma I, Vennekens K, Vanderlinden J, Sainlos M, de Wit J, Choquet D, Thoumine O. MDGAs are fast-diffusing molecules that delay excitatory synapse development by altering neuroligin behavior. eLife 2022; 11:75233. [PMID: 35532105 PMCID: PMC9084894 DOI: 10.7554/elife.75233] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 04/11/2022] [Indexed: 12/28/2022] Open
Abstract
MDGA molecules can bind neuroligins and interfere with trans-synaptic interactions to neurexins, thereby impairing synapse development. However, the subcellular localization and dynamics of MDGAs, or their specific action mode in neurons remain unclear. Here, surface immunostaining of endogenous MDGAs and single molecule tracking of recombinant MDGAs in dissociated hippocampal neurons reveal that MDGAs are homogeneously distributed and exhibit fast membrane diffusion, with a small reduction in mobility across neuronal maturation. Knocking-down/out MDGAs using shRNAs and CRISPR/Cas9 strategies increases the density of excitatory synapses, the membrane confinement of neuroligin-1, and the phosphotyrosine level of neuroligins associated with excitatory post-synaptic differentiation. Finally, MDGA silencing reduces the mobility of AMPA receptors, increases the frequency of miniature EPSCs (but not IPSCs), and selectively enhances evoked AMPA-receptor-mediated EPSCs in CA1 pyramidal neurons. Overall, our results support a mechanism by which interactions between MDGAs and neuroligin-1 delays the assembly of functional excitatory synapses containing AMPA receptors.
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Affiliation(s)
- Andrea Toledo
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Mathieu Letellier
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Giorgia Bimbi
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Béatrice Tessier
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Sophie Daburon
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Alexandre Favereaux
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Ingrid Chamma
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Kristel Vennekens
- VIB Center for Brain & Disease Research and KU Leuven, Department of Neurosciences, Leuven Brain Institute
| | - Jeroen Vanderlinden
- VIB Center for Brain & Disease Research and KU Leuven, Department of Neurosciences, Leuven Brain Institute
| | - Matthieu Sainlos
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
| | - Joris de Wit
- VIB Center for Brain & Disease Research and KU Leuven, Department of Neurosciences, Leuven Brain Institute
| | - Daniel Choquet
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
- University of Bordeaux, CNRS UAR 3420, INSERM, Bordeaux Imaging Center
| | - Olivier Thoumine
- University of Bordeaux, CNRS UMR 5297, Interdisciplinary Institute for Neuroscience
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14
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Lagardère M, Drouet A, Sainlos M, Thoumine O. High-Resolution Fluorescence Imaging Combined With Computer Simulations to Quantitate Surface Dynamics and Nanoscale Organization of Neuroligin-1 at Synapses. Front Synaptic Neurosci 2022; 14:835427. [PMID: 35546899 PMCID: PMC9083120 DOI: 10.3389/fnsyn.2022.835427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 03/09/2022] [Indexed: 11/13/2022] Open
Abstract
Neuroligins (NLGNs) form a family of cell adhesion molecules implicated in synapse development, but the mechanisms that retain these proteins at synapses are still incompletely understood. Recent studies indicate that surface-associated NLGN1 is diffusionally trapped at synapses, where it interacts with quasi-static scaffolding elements of the post-synaptic density. Whereas single molecule tracking reveals rapid diffusion and transient immobilization of NLGN1 at synapses within seconds, fluorescence recovery after photobleaching experiments indicate instead a long-term turnover of NLGN1 at synapse, in the hour time range. To gain insight into the mechanisms supporting NLGN1 anchorage at post-synapses and try to reconcile those experimental paradigms, we quantitatively analyzed here live-cell and super-resolution imaging experiments performed on NLGN1 using a newly released simulator of membrane protein dynamics for fluorescence microscopy, FluoSim. Based on a small set of parameters including diffusion coefficients, binding constants, and photophysical rates, the framework describes fairly well the dynamic behavior of extra-synaptic and synaptic NLGN1 over both short and long time ranges, and provides an estimate of NLGN1 copy numbers in post-synaptic densities at steady-state (around 50 dimers). One striking result is that the residence time of NLGN1 at synapses is much longer than what can be expected from extracellular interactions with pre-synaptic neurexins only, suggesting that NLGN1 is stabilized at synapses through multivalent interactions with intracellular post-synaptic scaffolding proteins.
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15
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Sando R, Ho ML, Liu X, Südhof TC. Engineered synaptic tools reveal localized cAMP signaling in synapse assembly. J Cell Biol 2022; 221:e202109111. [PMID: 34913963 PMCID: PMC8685283 DOI: 10.1083/jcb.202109111] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 11/15/2021] [Accepted: 11/30/2021] [Indexed: 12/18/2022] Open
Abstract
The physiological mechanisms driving synapse formation are elusive. Although numerous signals are known to regulate synapses, it remains unclear which signaling mechanisms organize initial synapse assembly. Here, we describe new tools, referred to as "SynTAMs" for synaptic targeting molecules, that enable localized perturbations of cAMP signaling in developing postsynaptic specializations. We show that locally restricted suppression of postsynaptic cAMP levels or of cAMP-dependent protein-kinase activity severely impairs excitatory synapse formation without affecting neuronal maturation, dendritic arborization, or inhibitory synapse formation. In vivo, suppression of postsynaptic cAMP signaling in CA1 neurons prevented formation of both Schaffer-collateral and entorhinal-CA1/temporoammonic-path synapses, suggesting a general principle. Retrograde trans-synaptic rabies virus tracing revealed that postsynaptic cAMP signaling is required for continuous replacement of synapses throughout life. Given that postsynaptic latrophilin adhesion-GPCRs drive synapse formation and produce cAMP, we suggest that spatially restricted postsynaptic cAMP signals organize assembly of postsynaptic specializations during synapse formation.
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Affiliation(s)
- Richard Sando
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
- Department of Pharmacology, Vanderbilt University, Nashville, TN
| | - Milan Lyndie Ho
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
| | - Xinran Liu
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT
| | - Thomas C. Südhof
- Department of Molecular and Cellular Physiology, Stanford University School of Medicine, Stanford, CA
- Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA
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16
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Kim J, Kim S, Kim H, Hwang IW, Bae S, Karki S, Kim D, Ogelman R, Bang G, Kim JY, Kajander T, Um JW, Oh WC, Ko J. MDGA1 negatively regulates amyloid precursor protein-mediated synapse inhibition in the hippocampus. Proc Natl Acad Sci U S A 2022; 119:e2115326119. [PMID: 35074912 PMCID: PMC8795569 DOI: 10.1073/pnas.2115326119] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 12/05/2021] [Indexed: 12/20/2022] Open
Abstract
Balanced synaptic inhibition, controlled by multiple synaptic adhesion proteins, is critical for proper brain function. MDGA1 (meprin, A-5 protein, and receptor protein-tyrosine phosphatase mu [MAM] domain-containing glycosylphosphatidylinositol anchor protein 1) suppresses synaptic inhibition in mammalian neurons, yet the molecular mechanisms underlying MDGA1-mediated negative regulation of GABAergic synapses remain unresolved. Here, we show that the MDGA1 MAM domain directly interacts with the extension domain of amyloid precursor protein (APP). Strikingly, MDGA1-mediated synaptic disinhibition requires the MDGA1 MAM domain and is prominent at distal dendrites of hippocampal CA1 pyramidal neurons. Down-regulation of APP in presynaptic GABAergic interneurons specifically suppressed GABAergic, but not glutamatergic, synaptic transmission strength and inputs onto both the somatic and dendritic compartments of hippocampal CA1 pyramidal neurons. Moreover, APP deletion manifested differential effects in somatostatin- and parvalbumin-positive interneurons in the hippocampal CA1, resulting in distinct alterations in inhibitory synapse numbers, transmission, and excitability. The infusion of MDGA1 MAM protein mimicked postsynaptic MDGA1 gain-of-function phenotypes that involve the presence of presynaptic APP. The overexpression of MDGA1 wild type or MAM, but not MAM-deleted MDGA1, in the hippocampal CA1 impaired novel object-recognition memory in mice. Thus, our results establish unique roles of APP-MDGA1 complexes in hippocampal neural circuits, providing unprecedented insight into trans-synaptic mechanisms underlying differential tuning of neuronal compartment-specific synaptic inhibition.
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Affiliation(s)
- Jinhu Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu 42988, Korea
| | - Seungjoon Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu 42988, Korea
| | - Hyeonho Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu 42988, Korea
| | - In-Wook Hwang
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Sungwon Bae
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu 42988, Korea
| | - Sudeep Karki
- Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
| | - Dongwook Kim
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu 42988, Korea
| | - Roberto Ogelman
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Geul Bang
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, Ochang 305-732, Korea
| | - Jin Young Kim
- Research Center for Bioconvergence Analysis, Korea Basic Science Institute, Ochang 305-732, Korea
| | - Tommi Kajander
- Institute of Biotechnology, University of Helsinki, 00014 Helsinki, Finland
| | - Ji Won Um
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu 42988, Korea
| | - Won Chan Oh
- Department of Pharmacology, University of Colorado School of Medicine, Aurora, CO 80045;
| | - Jaewon Ko
- Department of Brain and Cognitive Sciences, Daegu Gyeongbuk Institute of Science and Technology, Daegu 42988, Korea;
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17
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Matsubara S, Osugi T, Shiraishi A, Wada A, Satake H. Comparative analysis of transcriptomic profiles among ascidians, zebrafish, and mice: Insights from tissue-specific gene expression. PLoS One 2021; 16:e0254308. [PMID: 34559810 PMCID: PMC8462739 DOI: 10.1371/journal.pone.0254308] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2021] [Accepted: 09/12/2021] [Indexed: 11/18/2022] Open
Abstract
Tissue/organ-specific genes (TSGs) are important not only for understanding organ development and function, but also for investigating the evolutionary lineages of organs in animals. Here, we investigate the TSGs of 9 adult tissues of an ascidian, Ciona intestinalis Type A (Ciona robusta), which lies in the important position of being the sister group of vertebrates. RNA-seq and qRT-PCR identified the Ciona TSGs in each tissue, and BLAST searches identified their homologs in zebrafish and mice. Tissue distributions of the vertebrate homologs were analyzed and clustered using public RNA-seq data for 12 zebrafish and 30 mouse tissues. Among the vertebrate homologs of the Ciona TSGs in the neural complex, 48% and 63% showed high expression in the zebrafish and mouse brain, respectively, suggesting that the central nervous system is evolutionarily conserved in chordates. In contrast, vertebrate homologs of Ciona TSGs in the ovary, pharynx, and intestine were not consistently highly expressed in the corresponding tissues of vertebrates, suggesting that these organs have evolved in Ciona-specific lineages. Intriguingly, more TSG homologs of the Ciona stomach were highly expressed in the vertebrate liver (17-29%) and intestine (22-33%) than in the mouse stomach (5%). Expression profiles for these genes suggest that the biological roles of the Ciona stomach are distinct from those of their vertebrate counterparts. Collectively, Ciona tissues were categorized into 3 groups: i) high similarity to the corresponding vertebrate tissues (neural complex and heart), ii) low similarity to the corresponding vertebrate tissues (ovary, pharynx, and intestine), and iii) low similarity to the corresponding vertebrate tissues, but high similarity to other vertebrate tissues (stomach, endostyle, and siphons). The present study provides transcriptomic catalogs of adult ascidian tissues and significant insights into the evolutionary lineages of the brain, heart, and digestive tract of chordates.
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Affiliation(s)
- Shin Matsubara
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
- * E-mail:
| | - Tomohiro Osugi
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Akira Shiraishi
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Azumi Wada
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
| | - Honoo Satake
- Bioorganic Research Institute, Suntory Foundation for Life Sciences, Kyoto, Japan
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18
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Wang R, Wu Z, Liu M, Wu Y, Li Q, Ba Y, Zhang H, Cheng X, Zhou G, Huang H. Resveratrol reverses hippocampal synaptic markers injury and SIRT1 inhibition against developmental Pb exposure. Brain Res 2021; 1767:147567. [PMID: 34175265 DOI: 10.1016/j.brainres.2021.147567] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 05/30/2021] [Accepted: 06/21/2021] [Indexed: 12/01/2022]
Abstract
Lead (Pb) exposure damages synaptic structural plasticity that results in cognitive impairment. Resveratrol, a natural polyphenolic compound, is one of the most potent agonists of silencing information regulator 1 (SIRT1) discovered to date. However, the effects of SIRT1 on synaptic functional plasticity in early life Pb exposure are not well studied. Herein, the purpose of this study is to investigate the expression of synaptic markers and SIRT1 in rats exposed to Pb and to evaluate the regulatory effect of resveratrol during this process. The Pb exposed male SD pups were treated with resveratrol (50 mg/kg/d) or EDTA (150 mg/kg/d) followed by hippocampal and blood sampling for analysis at postnatal day 21 (PND21). In the Morrris water maze test, resveratrol treatement protected the rats against Pb-induced impairment of learning and memory (P < 0.05). Resveratrol also enhanced the expression of brain-derived neurotrophic factor (BDNF, P < 0.001 vs 0.2% Pb group), and reversed the effects of Pb exposure on SIRT1(P < 0.001 vs 0.2% Pb group). The DG, CA1 and CA3 regions of the hippocampus showed a considerable increase in the expression of pre- and postsynaptic proteins (P < 0.001 vs 0.2% Pb group). In conclusion, our study demonstrated that resveratrol, through the activation of SIRT1, played a protective role against Pb-induced defects in synaptic plasticity, and suggested a new potential adjuvant treatment for Pb poisoning.
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Affiliation(s)
- Ruike Wang
- Department of Environmental Health, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province, China; Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province 450001, China
| | - Zuntao Wu
- Department of Environmental Health, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province, China; Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province 450001, China
| | - Mengchen Liu
- Department of Environmental Health, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province, China; Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province 450001, China
| | - Yingying Wu
- Department of Environmental Health, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province, China; Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province 450001, China
| | - Qiong Li
- Department of Environmental Health, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province, China; Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province 450001, China
| | - Yue Ba
- Department of Environmental Health, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province, China; Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province 450001, China
| | - Huizhen Zhang
- Department of Environmental Health, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province, China; Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province 450001, China
| | - Xuemin Cheng
- Department of Environmental Health, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province, China; Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province 450001, China
| | - Guoyu Zhou
- Department of Environmental Health, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province, China; Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province 450001, China
| | - Hui Huang
- Department of Environmental Health, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province, China; Environment and Health Innovation Team, College of Public Health, Zhengzhou University, Zhengzhou, Henan Province 450001, China.
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19
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Steffen DM, Ferri SL, Marcucci CG, Blocklinger KL, Molumby MJ, Abel T, Weiner JA. The γ-Protocadherins Interact Physically and Functionally with Neuroligin-2 to Negatively Regulate Inhibitory Synapse Density and Are Required for Normal Social Interaction. Mol Neurobiol 2021; 58:2574-2589. [PMID: 33471287 PMCID: PMC8137559 DOI: 10.1007/s12035-020-02263-z] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 12/15/2020] [Indexed: 12/16/2022]
Abstract
Cell adhesion molecules (CAMs) are key players in the formation of neural circuits during development. The γ-protocadherins (γ-Pcdhs), a family of 22 CAMs encoded by the Pcdhg gene cluster, are known to play important roles in dendrite arborization, axon targeting, and synapse development. We showed previously that multiple γ-Pcdhs interact physically with the autism-associated CAM neuroligin-1, and inhibit the latter's ability to promote excitatory synapse maturation. Here, we show that γ-Pcdhs can also interact physically with the related neuroligin-2, and inhibit this CAM's ability to promote inhibitory synapse development. In an artificial synapse assay, γ-Pcdhs co-expressed with neuroligin-2 in non-neuronal cells reduce inhibitory presynaptic maturation in contacting hippocampal axons. Mice lacking the γ-Pcdhs from the forebrain (including the cortex, the hippocampus, and portions of the amygdala) exhibit increased inhibitory synapse density and increased co-localization of neuroligin-2 with inhibitory postsynaptic markers in vivo. These Pcdhg mutants also exhibit defective social affiliation and an anxiety-like phenotype in behavioral assays. Together, these results suggest that γ-Pcdhs negatively regulate neuroligins to limit synapse density in a manner that is important for normal behavior.
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Affiliation(s)
- David M Steffen
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, 52242, USA
- Department of Biology, The University of Iowa, Iowa City, IA, 52242, USA
| | - Sarah L Ferri
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, 52242, USA
- Department of Neuroscience and Pharmacology, Carver College of Medicine, The University of Iowa, Iowa City, IA, 52242, USA
| | - Charles G Marcucci
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, 52242, USA
- Department of Biology, The University of Iowa, Iowa City, IA, 52242, USA
| | - Kelsey L Blocklinger
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, 52242, USA
- Department of Neuroscience and Pharmacology, Carver College of Medicine, The University of Iowa, Iowa City, IA, 52242, USA
| | - Michael J Molumby
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, 52242, USA
- Department of Biology, The University of Iowa, Iowa City, IA, 52242, USA
| | - Ted Abel
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, 52242, USA
- Department of Neuroscience and Pharmacology, Carver College of Medicine, The University of Iowa, Iowa City, IA, 52242, USA
| | - Joshua A Weiner
- Iowa Neuroscience Institute, The University of Iowa, Iowa City, IA, 52242, USA.
- Department of Biology, The University of Iowa, Iowa City, IA, 52242, USA.
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20
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Interplay between hevin, SPARC, and MDGAs: Modulators of neurexin-neuroligin transsynaptic bridges. Structure 2021; 29:664-678.e6. [PMID: 33535026 DOI: 10.1016/j.str.2021.01.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 12/20/2020] [Accepted: 01/08/2021] [Indexed: 12/18/2022]
Abstract
Hevin is secreted by astrocytes and its synaptogenic effects are antagonized by the related protein, SPARC. Hevin stabilizes neurexin-neuroligin transsynaptic bridges in vivo. A third protein, membrane-tethered MDGA, blocks these bridges. Here, we reveal the molecular underpinnings of a regulatory network formed by this trio of proteins. The hevin FS-EC structure differs from SPARC, in that the EC domain appears rearranged around a conserved core. The FS domain is structurally conserved and it houses nanomolar affinity binding sites for neurexin and neuroligin. SPARC also binds neurexin and neuroligin, competing with hevin, so its antagonist action is rooted in its shortened N-terminal region. Strikingly, the hevin FS domain competes with MDGA for an overlapping binding site on neuroligin, while the hevin EC domain binds the extracellular matrix protein collagen (like SPARC), so that this trio of proteins can regulate neurexin-neuroligin transsynaptic bridges and also extracellular matrix interactions, impacting synapse formation and ultimately neural circuits.
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21
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Ali H, Marth L, Krueger-Burg D. Neuroligin-2 as a central organizer of inhibitory synapses in health and disease. Sci Signal 2020; 13:13/663/eabd8379. [DOI: 10.1126/scisignal.abd8379] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Postsynaptic organizational protein complexes play central roles both in orchestrating synapse formation and in defining the functional properties of synaptic transmission that together shape the flow of information through neuronal networks. A key component of these organizational protein complexes is the family of synaptic adhesion proteins called neuroligins. Neuroligins form transsynaptic bridges with presynaptic neurexins to regulate various aspects of excitatory and inhibitory synaptic transmission. Neuroligin-2 (NLGN2) is the only member that acts exclusively at GABAergic inhibitory synapses. Altered expression and mutations in NLGN2 and several of its interacting partners are linked to cognitive and psychiatric disorders, including schizophrenia, autism, and anxiety. Research on NLGN2 has fundamentally shaped our understanding of the molecular architecture of inhibitory synapses. Here, we discuss the current knowledge on the molecular and cellular functions of mammalian NLGN2 and its role in the neuronal circuitry that regulates behavior in rodents and humans.
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Affiliation(s)
- Heba Ali
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
- Göttingen Graduate School for Neurosciences, Biophysics, and Molecular Biosciences, University of Göttingen, 37077 Göttingen, Germany
| | - Lena Marth
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
| | - Dilja Krueger-Burg
- Department of Molecular Neurobiology, Max Planck Institute of Experimental Medicine, 37075 Göttingen, Germany
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, 37075 Göttingen, Germany
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22
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Trobiani L, Meringolo M, Diamanti T, Bourne Y, Marchot P, Martella G, Dini L, Pisani A, De Jaco A, Bonsi P. The neuroligins and the synaptic pathway in Autism Spectrum Disorder. Neurosci Biobehav Rev 2020; 119:37-51. [PMID: 32991906 DOI: 10.1016/j.neubiorev.2020.09.017] [Citation(s) in RCA: 45] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 09/11/2020] [Accepted: 09/19/2020] [Indexed: 12/13/2022]
Abstract
The genetics underlying autism spectrum disorder (ASD) is complex and heterogeneous, and de novo variants are found in genes converging in functional biological processes. Neuronal communication, including trans-synaptic signaling involving two families of cell-adhesion proteins, the presynaptic neurexins and the postsynaptic neuroligins, is one of the most recurrently affected pathways in ASD. Given the role of these proteins in determining synaptic function, abnormal synaptic plasticity and failure to establish proper synaptic contacts might represent mechanisms underlying risk of ASD. More than 30 mutations have been found in the neuroligin genes. Most of the resulting residue substitutions map in the extracellular, cholinesterase-like domain of the protein, and impair protein folding and trafficking. Conversely, the stalk and intracellular domains are less affected. Accordingly, several genetic animal models of ASD have been generated, showing behavioral and synaptic alterations. The aim of this review is to discuss the current knowledge on ASD-linked mutations in the neuroligin proteins and their effect on synaptic function, in various brain areas and circuits.
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Affiliation(s)
- Laura Trobiani
- Dept. Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Maria Meringolo
- Lab. Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy; Dept. Systems Medicine, University Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Tamara Diamanti
- Dept. Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Yves Bourne
- Lab. "Architecture et Fonction des Macromolécules Biologiques", CNRS/Aix Marseille Univ, Faculté des Sciences - Campus Luminy, 163 Avenue de Luminy, 13288 Marseille cedex 09, France
| | - Pascale Marchot
- Lab. "Architecture et Fonction des Macromolécules Biologiques", CNRS/Aix Marseille Univ, Faculté des Sciences - Campus Luminy, 163 Avenue de Luminy, 13288 Marseille cedex 09, France
| | - Giuseppina Martella
- Lab. Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy; Dept. Systems Medicine, University Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Luciana Dini
- Dept. Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy
| | - Antonio Pisani
- Lab. Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy; Dept. Systems Medicine, University Tor Vergata, Via Montpellier 1, 00133 Rome, Italy
| | - Antonella De Jaco
- Dept. Biology and Biotechnology, Sapienza University of Rome, P.le Aldo Moro 5, 00185 Rome, Italy.
| | - Paola Bonsi
- Lab. Neurophysiology and Plasticity, IRCCS Fondazione Santa Lucia, Via del Fosso di Fiorano 64, 00143 Rome, Italy.
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23
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SPARCL1 Promotes Excitatory But Not Inhibitory Synapse Formation and Function Independent of Neurexins and Neuroligins. J Neurosci 2020; 40:8088-8102. [PMID: 32973045 DOI: 10.1523/jneurosci.0454-20.2020] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 06/17/2020] [Accepted: 07/12/2020] [Indexed: 12/17/2022] Open
Abstract
Emerging evidence supports roles for secreted extracellular matrix proteins in boosting synaptogenesis, synaptic transmission, and synaptic plasticity. SPARCL1 (also known as Hevin), a secreted non-neuronal protein, was reported to increase synaptogenesis by simultaneously binding to presynaptic neurexin-1α and to postsynaptic neuroligin-1B, thereby catalyzing formation of trans-synaptic neurexin/neuroligin complexes. However, neurexins and neuroligins do not themselves mediate synaptogenesis, raising the question of how SPARCL1 enhances synapse formation by binding to these molecules. Moreover, it remained unclear whether SPARCL1 acts on all synapses containing neurexins and neuroligins or only on a subset of synapses, and whether it enhances synaptic transmission in addition to boosting synaptogenesis or induces silent synapses. To explore these questions, we examined the synaptic effects of SPARCL1 and their dependence on neurexins and neuroligins. Using mixed neuronal and glial cultures from neonatal mouse cortex of both sexes, we show that SPARCL1 selectively increases excitatory but not inhibitory synapse numbers, enhances excitatory but not inhibitory synaptic transmission, and augments NMDAR-mediated synaptic responses more than AMPAR-mediated synaptic responses. None of these effects were mediated by SPARCL1-binding to neurexins or neuroligins. Neurons from triple neurexin-1/2/3 or from quadruple neuroligin-1/2/3/4 conditional KO mice that lacked all neurexins or all neuroligins were fully responsive to SPARCL1. Together, our results reveal that SPARCL1 selectively boosts excitatory but not inhibitory synaptogenesis and synaptic transmission by a novel mechanism that is independent of neurexins and neuroligins.SIGNIFICANCE STATEMENT Emerging evidence supports roles for extracellular matrix proteins in boosting synapse formation and function. Previous studies demonstrated that SPARCL1, a secreted non-neuronal protein, promotes synapse formation in rodent and human neurons. However, it remained unclear whether SPARCL1 acts on all or on only a subset of synapses, induces functional or largely inactive synapses, and generates synapses by bridging presynaptic neurexins and postsynaptic neuroligins. Here, we report that SPARCL1 selectively induces excitatory synapses, increases their efficacy, and enhances their NMDAR content. Moreover, using rigorous genetic manipulations, we show that SPARCL1 does not require neurexins and neuroligins for its activity. Thus, SPARCL1 selectively boosts excitatory synaptogenesis and synaptic transmission by a novel mechanism that is independent of neurexins and neuroligins.
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24
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Fertan E, Wong AA, Purdon MK, Weaver ICG, Brown RE. The effect of background strain on the behavioral phenotypes of the MDGA2 +/- mouse model of autism spectrum disorder. GENES BRAIN AND BEHAVIOR 2020; 20:e12696. [PMID: 32808443 DOI: 10.1111/gbb.12696] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 07/27/2020] [Accepted: 08/14/2020] [Indexed: 12/26/2022]
Abstract
The membrane-associated mucin (MAM) domain containing glycosylphosphatidylinositol anchor 2 protein single knock-out mice (MDGA2+/- ) are models of ASD. We examined the behavioral phenotypes of male and female MDGA2+/- and wildtype mice on C57BL6/NJ and C57BL6/N backgrounds at 2 months of age and measured MDGA2, neuroligin 1 and neuroligin 2 levels at 7 months. Mice on the C57BL6/NJ background performed better than those on the C57BL6/N background in visual ability and in learning and memory performance in the Morris water maze and differed in measures of motor behavior and anxiety. Mice with the MDGA2+/- genotype differed from WT mice in motor, social and repetitive behavior and anxiety, but most of these effects involved interactions between MDGA2+/- genotype and background strain. The background strain also influenced MDGA2 levels and NLGN2 association in MDGA2+/- mice. Our findings emphasize the importance of the background strain used in studies of genetically modified mice.
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Affiliation(s)
- Emre Fertan
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Aimée A Wong
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Michaela K Purdon
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Ian C G Weaver
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Psychiatry, Dalhousie University, Halifax, Nova Scotia, Canada.,Department of Pathology, Dalhousie University, Halifax, Nova Scotia, Canada.,Brain Repair Centre, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Richard E Brown
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada.,Brain Repair Centre, Dalhousie University, Halifax, Nova Scotia, Canada
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25
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Oku S, Feng H, Connor S, Toledo A, Zhang P, Zhang Y, Thoumine O, Zhang C, Craig AM. Alternative splicing at neuroligin site A regulates glycan interaction and synaptogenic activity. eLife 2020; 9:58668. [PMID: 32915137 PMCID: PMC7486126 DOI: 10.7554/elife.58668] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 08/31/2020] [Indexed: 01/18/2023] Open
Abstract
Post-transcriptional mechanisms regulating cell surface synaptic organizing complexes that control the properties of connections in brain circuits are poorly understood. Alternative splicing regulates the prototypical synaptic organizing complex, neuroligin-neurexin. In contrast to the well-studied neuroligin splice site B, little is known about splice site A. We discovered that inclusion of the positively charged A1 insert in mouse neuroligin-1 increases its binding to heparan sulphate, a modification on neurexin. The A1 insert increases neurexin recruitment, presynaptic differentiation, and synaptic transmission mediated by neuroligin-1. We propose that the A1 insert could be a target for alleviating the consequences of deleterious NLGN1/3 mutations, supported by assays with the autism-linked neuroligin-1-P89L mutant. An enrichment of neuroligin-1 A1 in GABAergic neuron types suggests a role in synchrony of cortical circuits. Altogether, these data reveal an unusual mode by which neuroligin splicing controls synapse development through protein-glycan interaction and identify it as a potential therapeutic target.
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Affiliation(s)
- Shinichiro Oku
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Huijuan Feng
- Departments of Systems Biology and Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, United States
| | - Steven Connor
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada.,Department of Biology, York University, Toronto, Canada
| | - Andrea Toledo
- Interdisciplinary Institute for Neuroscience UMR 5297, CNRS and University of Bordeaux, Bordeaux, France
| | - Peng Zhang
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Yue Zhang
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada
| | - Olivier Thoumine
- Interdisciplinary Institute for Neuroscience UMR 5297, CNRS and University of Bordeaux, Bordeaux, France
| | - Chaolin Zhang
- Departments of Systems Biology and Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, United States
| | - Ann Marie Craig
- Djavad Mowafaghian Centre for Brain Health and Department of Psychiatry, University of British Columbia, Vancouver, Canada
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26
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Rudan Njavro J, Klotz J, Dislich B, Wanngren J, Shmueli MD, Herber J, Kuhn PH, Kumar R, Koeglsperger T, Conrad M, Wurst W, Feederle R, Vlachos A, Michalakis S, Jedlicka P, Müller SA, Lichtenthaler SF. Mouse brain proteomics establishes MDGA1 and CACHD1 as in vivo substrates of the Alzheimer protease BACE1. FASEB J 2019; 34:2465-2482. [PMID: 31908000 DOI: 10.1096/fj.201902347r] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2019] [Revised: 11/22/2019] [Accepted: 12/03/2019] [Indexed: 01/18/2023]
Abstract
The protease beta-site APP cleaving enzyme 1 (BACE1) has fundamental functions in the nervous system. Its inhibition is a major therapeutic approach in Alzheimer's disease, because BACE1 cleaves the amyloid precursor protein (APP), thereby catalyzing the first step in the generation of the pathogenic amyloid beta (Aβ) peptide. Yet, BACE1 cleaves numerous additional membrane proteins besides APP. Most of these substrates have been identified in vitro, but only few were further validated or characterized in vivo. To identify BACE1 substrates with in vivo relevance, we used isotope label-based quantitative proteomics of wild type and BACE1-deficient (BACE1 KO) mouse brains. This approach identified known BACE1 substrates, including Close homolog of L1 and contactin-2, which were found to be enriched in the membrane fraction of BACE1 KO brains. VWFA and cache domain-containing protein 1 (CACHD)1 and MAM domain-containing glycosylphosphatidylinositol anchor protein 1 (MDGA1), which have functions in synaptic transmission, were identified and validated as new BACE1 substrates in vivo by immunoblots using primary neurons and mouse brains. Inhibition or deletion of BACE1 from primary neurons resulted in a pronounced inhibition of substrate cleavage and a concomitant increase in full-length protein levels of CACHD1 and MDGA1. The BACE1 cleavage site in both proteins was determined to be located within the juxtamembrane domain. In summary, this study identifies and validates CACHD1 and MDGA1 as novel in vivo substrates for BACE1, suggesting that cleavage of both proteins may contribute to the numerous functions of BACE1 in the nervous system.
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Affiliation(s)
- Jasenka Rudan Njavro
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Jakob Klotz
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Bastian Dislich
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Institute of Pathology, University of Bern, Switzerland
| | - Johanna Wanngren
- Division of Neurogeriatrics, Department of NVS, Center for Alzheimer Research, Karolinska Institutet, Stockholm, Sweden
| | - Merav D Shmueli
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel
| | - Julia Herber
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Peer-Hendrik Kuhn
- Institute of Pathology, Technical University of Munich, Munich, Germany
| | - Rohit Kumar
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,Department of Neurology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Thomas Koeglsperger
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Department of Neurology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Marcus Conrad
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Wolfgang Wurst
- Institute of Developmental Genetics, Helmholtz Zentrum München, Neuherberg, Germany.,Genome Engineering, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Developmental Genetics, School of Life Sciences Weihenstephan, Technical University of Munich, Freising, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Regina Feederle
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,German Research Center for Environmental Health, Institute for Diabetes and Obesity, Monoclonal Antibody Core Facility, Helmholtz Zentrum München, Neuherberg, Germany.,Core Facility Monoclonal Antibodies, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Germany.,Center for Basics in Neuromodulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Germany
| | - Stylianos Michalakis
- Department of Ophthalmology, Ludwig Maximilian University of Munich, Munich, Germany
| | - Peter Jedlicka
- Faculty of Medicine, ICAR3R - Interdisciplinary Centre for 3Rs in Animal Research, Justus-Liebig-University, Giessen, Germany.,Neuroscience Center, Institute of Clinical Neuroanatomy, Goethe University, Frankfurt am Main, Germany.,Frankfurt Institute for Advanced Studies, Frankfurt am Main, Germany
| | - Stephan A Müller
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Stefan F Lichtenthaler
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Neuroproteomics, School of Medicine, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
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27
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Affiliation(s)
- Timothy A Ryan
- Department of Biochemistry, Weill Cornell Medical College, USA.
| | - Yishi Jin
- Neurobiology Section, University of California San Diego, USA.
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