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Bjornson KJ, Cahill ME. Assessing protein distribution and dendritic spine morphology relationships using structured illumination microscopy in cultured neurons. STAR Protoc 2024; 5:102829. [PMID: 38236769 PMCID: PMC10827590 DOI: 10.1016/j.xpro.2023.102829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Revised: 12/06/2023] [Accepted: 12/21/2023] [Indexed: 02/03/2024] Open
Abstract
Dendritic spines are protrusions on dendrites forming the postsynaptic aspect of excitatory connections within the brain. Spine morphology is associated with synaptic functional strength and the spatial regulation of protein nanodomains within dendritic spines is an important determinant of spine structure and function. Here, we present a protocol to resolve the nanoscale localization of proteins within dendritic spines using structured illumination microscopy. We describe steps for the structural analysis of dendritic spine parameters, protein localization analysis, and data processing. For complete details on the use and execution of this protocol, please refer to Bjornson et al.1.
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Affiliation(s)
- Kathryn J Bjornson
- Department of Comparative Biosciences, University of Wisconsin, Madison, WI 53706, USA.
| | - Michael E Cahill
- Department of Comparative Biosciences, University of Wisconsin, Madison, WI 53706, USA.
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2
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Castillo-Armengol J, Marzetta F, Rodriguez Sanchez-Archidona A, Fledelius C, Evans M, McNeilly A, McCrimmon RJ, Ibberson M, Thorens B. Disrupted hypothalamic transcriptomics and proteomics in a mouse model of type 2 diabetes exposed to recurrent hypoglycaemia. Diabetologia 2024; 67:371-391. [PMID: 38017352 PMCID: PMC10789691 DOI: 10.1007/s00125-023-06043-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 09/07/2023] [Indexed: 11/30/2023]
Abstract
AIMS/HYPOTHESIS Repeated exposures to insulin-induced hypoglycaemia in people with diabetes progressively impairs the counterregulatory response (CRR) that restores normoglycaemia. This defect is characterised by reduced secretion of glucagon and other counterregulatory hormones. Evidence indicates that glucose-responsive neurons located in the hypothalamus orchestrate the CRR. Here, we aimed to identify the changes in hypothalamic gene and protein expression that underlie impaired CRR in a mouse model of defective CRR. METHODS High-fat-diet fed and low-dose streptozocin-treated C57BL/6N mice were exposed to one (acute hypoglycaemia [AH]) or multiple (recurrent hypoglycaemia [RH]) insulin-induced hypoglycaemic episodes and plasma glucagon levels were measured. Single-nuclei RNA-seq (snRNA-seq) data were obtained from the hypothalamus and cortex of mice exposed to AH and RH. Proteomic data were obtained from hypothalamic synaptosomal fractions. RESULTS The final insulin injection resulted in similar plasma glucose levels in the RH group and AH groups, but glucagon secretion was significantly lower in the RH group (AH: 94.5±9.2 ng/l [n=33]; RH: 59.0±4.8 ng/l [n=37]; p<0.001). Analysis of snRNA-seq data revealed similar proportions of hypothalamic cell subpopulations in the AH- and RH-exposed mice. Changes in transcriptional profiles were found in all cell types analysed. In neurons from RH-exposed mice, we observed a significant decrease in expression of Avp, Pmch and Pcsk1n, and the most overexpressed gene was Kcnq1ot1, as compared with AH-exposed mice. Gene ontology analysis of differentially expressed genes (DEGs) indicated a coordinated decrease in many oxidative phosphorylation genes and reduced expression of vacuolar H+- and Na+/K+-ATPases; these observations were in large part confirmed in the proteomic analysis of synaptosomal fractions. Compared with AH-exposed mice, oligodendrocytes from RH-exposed mice had major changes in gene expression that suggested reduced myelin formation. In astrocytes from RH-exposed mice, DEGs indicated reduced capacity for neurotransmitters scavenging in tripartite synapses as compared with astrocytes from AH-exposed mice. In addition, in neurons and astrocytes, multiple changes in gene expression suggested increased amyloid beta (Aβ) production and stability. The snRNA-seq analysis of the cortex showed that the adaptation to RH involved different biological processes from those seen in the hypothalamus. CONCLUSIONS/INTERPRETATION The present study provides a model of defective counterregulation in a mouse model of type 2 diabetes. It shows that repeated hypoglycaemic episodes induce multiple defects affecting all hypothalamic cell types and their interactions, indicative of impaired neuronal network signalling and dysegulated hypoglycaemia sensing, and displaying features of neurodegenerative diseases. It also shows that repeated hypoglycaemia leads to specific molecular adaptation in the hypothalamus when compared with the cortex. DATA AVAILABILITY The transcriptomic dataset is available via the GEO ( http://www.ncbi.nlm.nih.gov/geo/ ), using the accession no. GSE226277. The proteomic dataset is available via the ProteomeXchange data repository ( http://www.proteomexchange.org ), using the accession no. PXD040183.
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Affiliation(s)
- Judit Castillo-Armengol
- Novo Nordisk A/S, Måløv, Denmark
- Center for Integrative Genomics (CIG), University of Lausanne, Lausanne, Switzerland
| | - Flavia Marzetta
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | | | | | - Mark Evans
- IMS Metabolic Research Laboratories, Addenbrookes Biomedical Campus, Cambridge, UK
| | | | | | - Mark Ibberson
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland
| | - Bernard Thorens
- Center for Integrative Genomics (CIG), University of Lausanne, Lausanne, Switzerland.
- Vital-IT Group, SIB Swiss Institute of Bioinformatics, Lausanne, Switzerland.
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3
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Cao YY, Wu LL, Li XN, Yuan YL, Zhao WW, Qi JX, Zhao XY, Ward N, Wang J. Molecular Mechanisms of AMPA Receptor Trafficking in the Nervous System. Int J Mol Sci 2023; 25:111. [PMID: 38203282 PMCID: PMC10779435 DOI: 10.3390/ijms25010111] [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: 11/24/2023] [Revised: 12/15/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
Synaptic plasticity enhances or reduces connections between neurons, affecting learning and memory. Postsynaptic AMPARs mediate greater than 90% of the rapid excitatory synaptic transmission in glutamatergic neurons. The number and subunit composition of AMPARs are fundamental to synaptic plasticity and the formation of entire neural networks. Accordingly, the insertion and functionalization of AMPARs at the postsynaptic membrane have become a core issue related to neural circuit formation and information processing in the central nervous system. In this review, we summarize current knowledge regarding the related mechanisms of AMPAR expression and trafficking. The proteins related to AMPAR trafficking are discussed in detail, including vesicle-related proteins, cytoskeletal proteins, synaptic proteins, and protein kinases. Furthermore, significant emphasis was placed on the pivotal role of the actin cytoskeleton, which spans throughout the entire transport process in AMPAR transport, indicating that the actin cytoskeleton may serve as a fundamental basis for AMPAR trafficking. Additionally, we summarize the proteases involved in AMPAR post-translational modifications. Moreover, we provide an overview of AMPAR transport and localization to the postsynaptic membrane. Understanding the assembly, trafficking, and dynamic synaptic expression mechanisms of AMPAR may provide valuable insights into the cognitive decline associated with neurodegenerative diseases.
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Affiliation(s)
- Yi-Yang Cao
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai 200444, China; (Y.-Y.C.); (X.-N.L.); (Y.-L.Y.); (W.-W.Z.); (J.-X.Q.); (X.-Y.Z.)
| | - Ling-Ling Wu
- School of Medicine, Shanghai University, Shanghai 200444, China;
| | - Xiao-Nan Li
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai 200444, China; (Y.-Y.C.); (X.-N.L.); (Y.-L.Y.); (W.-W.Z.); (J.-X.Q.); (X.-Y.Z.)
| | - Yu-Lian Yuan
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai 200444, China; (Y.-Y.C.); (X.-N.L.); (Y.-L.Y.); (W.-W.Z.); (J.-X.Q.); (X.-Y.Z.)
| | - Wan-Wei Zhao
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai 200444, China; (Y.-Y.C.); (X.-N.L.); (Y.-L.Y.); (W.-W.Z.); (J.-X.Q.); (X.-Y.Z.)
| | - Jing-Xuan Qi
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai 200444, China; (Y.-Y.C.); (X.-N.L.); (Y.-L.Y.); (W.-W.Z.); (J.-X.Q.); (X.-Y.Z.)
| | - Xu-Yu Zhao
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai 200444, China; (Y.-Y.C.); (X.-N.L.); (Y.-L.Y.); (W.-W.Z.); (J.-X.Q.); (X.-Y.Z.)
| | - Natalie Ward
- Medical Laboratory, Exceptional Community Hospital, 19060 N John Wayne Pkwy, Maricopa, AZ 85139, USA;
| | - Jiao Wang
- Laboratory of Molecular Neural Biology, School of Life Sciences, Shanghai University, Shanghai 200444, China; (Y.-Y.C.); (X.-N.L.); (Y.-L.Y.); (W.-W.Z.); (J.-X.Q.); (X.-Y.Z.)
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4
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Ripoli C, Dagliyan O, Renna P, Pastore F, Paciello F, Sollazzo R, Rinaudo M, Battistoni M, Martini S, Tramutola A, Sattin A, Barone E, Saneyoshi T, Fellin T, Hayashi Y, Grassi C. Engineering memory with an extrinsically disordered kinase. SCIENCE ADVANCES 2023; 9:eadh1110. [PMID: 37967196 PMCID: PMC10651130 DOI: 10.1126/sciadv.adh1110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2023] [Accepted: 10/13/2023] [Indexed: 11/17/2023]
Abstract
Synaptic plasticity plays a crucial role in memory formation by regulating the communication between neurons. Although actin polymerization has been linked to synaptic plasticity and dendritic spine stability, the causal link between actin polymerization and memory encoding has not been identified yet. It is not clear whether actin polymerization and structural changes in dendritic spines are a driver or a consequence of learning and memory. Using an extrinsically disordered form of the protein kinase LIMK1, which rapidly and precisely acts on ADF/cofilin, a direct modifier of actin, we induced long-term enlargement of dendritic spines and enhancement of synaptic transmission in the hippocampus on command. The activation of extrinsically disordered LIMK1 in vivo improved memory encoding and slowed cognitive decline in aged mice exhibiting reduced cofilin phosphorylation. The engineered memory by an extrinsically disordered LIMK1 supports a direct causal link between actin-mediated synaptic transmission and memory.
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Affiliation(s)
- Cristian Ripoli
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Onur Dagliyan
- Division of Molecular Neurobiology, Department of Medical Biochemistry and Biophysics, Karolinska Institute, 17165 Stockholm, Sweden
| | - Pietro Renna
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Francesco Pastore
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Fabiola Paciello
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Raimondo Sollazzo
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Marco Rinaudo
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
| | - Martina Battistoni
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Sara Martini
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
| | - Antonella Tramutola
- Department of Biochemical Sciences “A. Rossi-Fanelli”, Sapienza University of Rome, 00185 Rome, Italy
| | - Andrea Sattin
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, 16163 Genoa, Italy
| | - Eugenio Barone
- Department of Biochemical Sciences “A. Rossi-Fanelli”, Sapienza University of Rome, 00185 Rome, Italy
| | - Takeo Saneyoshi
- Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
| | - Tommaso Fellin
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, 16163 Genoa, Italy
| | - Yasunori Hayashi
- Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan
| | - Claudio Grassi
- Department of Neuroscience, Università Cattolica del Sacro Cuore, 00168 Rome, Italy
- Fondazione Policlinico Universitario A. Gemelli IRCCS, 00168 Rome, Italy
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5
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Wang Y, Troughton LD, Xu F, Chatterjee A, Ding C, Zhao H, Cifuentes LP, Wagner RB, Wang T, Tan S, Chen J, Li L, Umulis D, Kuang S, Suter DM, Yuan C, Chan D, Huang F, Oakes PW, Deng Q. Atypical peripheral actin band formation via overactivation of RhoA and nonmuscle myosin II in mitofusin 2-deficient cells. eLife 2023; 12:e88828. [PMID: 37724949 PMCID: PMC10550287 DOI: 10.7554/elife.88828] [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: 04/21/2023] [Accepted: 09/19/2023] [Indexed: 09/21/2023] Open
Abstract
Cell spreading and migration play central roles in many physiological and pathophysiological processes. We have previously shown that MFN2 regulates the migration of human neutrophil-like cells via suppressing Rac activation. Here, we show that in mouse embryonic fibroblasts, MFN2 suppresses RhoA activation and supports cell polarization. After initial spreading, the wild-type cells polarize and migrate, whereas the Mfn2-/- cells maintain a circular shape. Increased cytosolic Ca2+ resulting from the loss of Mfn2 is directly responsible for this phenotype, which can be rescued by expressing an artificial tether to bring mitochondria and endoplasmic reticulum to close vicinity. Elevated cytosolic Ca2+ activates Ca2+/calmodulin-dependent protein kinase II, RhoA, and myosin light-chain kinase, causing an overactivation of nonmuscle myosin II, leading to a formation of a prominent F-actin ring at the cell periphery and increased cell contractility. The peripheral actin band alters cell physics and is dependent on substrate rigidity. Our results provide a novel molecular basis to understand how MFN2 regulates distinct signaling pathways in different cells and tissue environments, which is instrumental in understanding and treating MFN2-related diseases.
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Affiliation(s)
- Yueyang Wang
- Department of Biological Sciences, Purdue University West LafayetteWest LafayetteUnited States
| | - Lee D Troughton
- Cell and Molecular Physiology, Loyola University ChicagoChicagoUnited States
| | - Fan Xu
- Weldon School of Biomedical Engineering, Purdue University West LafayetteWest LafayetteUnited States
- Advanced Research Institute of Multidisciplinary Science, Beijing Institute of TechnologyBeijingChina
| | - Aritra Chatterjee
- Weldon School of Biomedical Engineering, Purdue University West LafayetteWest LafayetteUnited States
| | - Chang Ding
- Department of Biological Sciences, Purdue University West LafayetteWest LafayetteUnited States
| | - Han Zhao
- Davidson School of Chemical Engineering, Purdue University West LafayetteWest LafayetteUnited States
| | - Laura P Cifuentes
- Department of Biological Sciences, Purdue University West LafayetteWest LafayetteUnited States
| | - Ryan B Wagner
- School of Mechanical Engineering, Purdue University West LafayetteWest LafayetteUnited States
| | - Tianqi Wang
- Department of Biological Sciences, Purdue University West LafayetteWest LafayetteUnited States
| | - Shelly Tan
- Department of Biological Sciences, Purdue University West LafayetteWest LafayetteUnited States
| | - Jingjuan Chen
- Department of Animal Sciences, Purdue University West LafayetteWest LafayetteUnited States
| | - Linlin Li
- Weldon School of Biomedical Engineering, Purdue University West LafayetteWest LafayetteUnited States
| | - David Umulis
- Weldon School of Biomedical Engineering, Purdue University West LafayetteWest LafayetteUnited States
- Department of Agricultural and Biological Engineering, Purdue University West LafayetteWest LafayetteUnited States
| | - Shihuan Kuang
- Department of Animal Sciences, Purdue University West LafayetteWest LafayetteUnited States
| | - Daniel M Suter
- Department of Biological Sciences, Purdue University West LafayetteWest LafayetteUnited States
- Purdue Institute for Integrative Neuroscience, Purdue University West LafayetteWest LafayetteUnited States
- Purdue Institute for Inflammation, Immunology & Infectious Disease, Purdue University West LafayetteWest LafayetteUnited States
| | - Chongli Yuan
- Davidson School of Chemical Engineering, Purdue University West LafayetteWest LafayetteUnited States
| | - Deva Chan
- Weldon School of Biomedical Engineering, Purdue University West LafayetteWest LafayetteUnited States
| | - Fang Huang
- Weldon School of Biomedical Engineering, Purdue University West LafayetteWest LafayetteUnited States
| | - Patrick W Oakes
- Cell and Molecular Physiology, Loyola University ChicagoChicagoUnited States
| | - Qing Deng
- Department of Biological Sciences, Purdue University West LafayetteWest LafayetteUnited States
- Purdue Institute for Inflammation, Immunology & Infectious Disease, Purdue University West LafayetteWest LafayetteUnited States
- Purdue University Center for Cancer Research, Purdue University West LafayetteWest LafayetteUnited States
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6
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Guo MS, Wu Q, Dong TT, Tsim KWK. The UV-induced uptake of melanosome by skin keratinocyte is triggered by α7 nicotinic acetylcholine receptor-mediated phagocytosis. FEBS J 2023; 290:724-744. [PMID: 36048140 DOI: 10.1111/febs.16613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Revised: 08/10/2022] [Accepted: 08/31/2022] [Indexed: 02/04/2023]
Abstract
The melanosome is an organelle that produces melanin for skin pigmentation, which is synthesized by epidermal melanocytes, subsequently transported and internalized by epidermal keratinocytes. Exposure to ultraviolet (UV) from sunlight radiation is a major stimulator of melanosome uptake by keratinocytes. Acetylcholine (ACh) is known to be released by keratinocytes under UV exposure, which regulates melanin production in melanocytes by participating in which has been named as 'skin synapse'. Here, the role of cholinergic molecules, i.e. ACh and α7 nicotinic acetylcholine receptor (nAChR), in regulating melanosome uptake through phagocytosis by keratinocytes was illustrated. In cultured keratinocytes (HaCaT cells), the fluorescent beads at different sizes imitating melanosomes, or melanosomes, were phagocytosed under UV exposure. The UV-induced phagocytosis in keratinocytes was markedly increased by applied ACh, an acetylcholinesterase (AChE) inhibitor or an α7 nAChR agonist. By contrast, the antagonist of α7 nAChR was able to fully block the UV-induced phagocytosis, suggesting the role of α7 nAChR in this event. The intracellular Ca++ mobilization was triggered by UV exposure, accounting for the initiation of phagocytosis. The blockage of UV-mediated Ca++ mobilization, triggered by BAPTA-AM or α7 nAChR antagonist, resulted in a complete termination of phagocytosis. Besides, the phosphorylation of cofilin, as well as expression and activation of RhoA, accounting for phagocytosis was induced by UV exposure: the phosphorylation was blocked by BAPTA-AM or α7 nAChR antagonist. The result suggests that the cholinergic system, especially α7 nAChR, is playing a regulatory role in modulating melanosome uptake in keratinocytes being induced by UV exposure.
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Affiliation(s)
- Maggie Suisui Guo
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Qiyun Wu
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Tina Tingxia Dong
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China.,Shenzhen Key Laboratory of Edible and Medicinal Bioresources, HKUST Shenzhen Research Institute, Shenzhen, China
| | - Karl Wah Keung Tsim
- Division of Life Science and State Key Laboratory of Molecular Neuroscience, The Hong Kong University of Science and Technology, Hong Kong, China.,Shenzhen Key Laboratory of Edible and Medicinal Bioresources, HKUST Shenzhen Research Institute, Shenzhen, China
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7
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Yasuda R, Hayashi Y, Hell JW. CaMKII: a central molecular organizer of synaptic plasticity, learning and memory. Nat Rev Neurosci 2022; 23:666-682. [PMID: 36056211 DOI: 10.1038/s41583-022-00624-2] [Citation(s) in RCA: 102] [Impact Index Per Article: 51.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/19/2022] [Indexed: 12/30/2022]
Abstract
Calcium-calmodulin (CaM)-dependent protein kinase II (CaMKII) is the most abundant protein in excitatory synapses and is central to synaptic plasticity, learning and memory. It is activated by intracellular increases in calcium ion levels and triggers molecular processes necessary for synaptic plasticity. CaMKII phosphorylates numerous synaptic proteins, thereby regulating their structure and functions. This leads to molecular events crucial for synaptic plasticity, such as receptor trafficking, localization and activity; actin cytoskeletal dynamics; translation; and even transcription through synapse-nucleus shuttling. Several new tools affording increasingly greater spatiotemporal resolution have revealed the link between CaMKII activity and downstream signalling processes in dendritic spines during synaptic and behavioural plasticity. These technologies have provided insights into the function of CaMKII in learning and memory.
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Affiliation(s)
- Ryohei Yasuda
- Max Planck Florida Institute for Neuroscience, Jupiter, FL, USA.
| | - Yasunori Hayashi
- Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, Davis, CA, USA.
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8
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Walker CK, Herskowitz JH. Dendritic Spines: Mediators of Cognitive Resilience in Aging and Alzheimer's Disease. Neuroscientist 2021; 27:487-505. [PMID: 32812494 PMCID: PMC8130863 DOI: 10.1177/1073858420945964] [Citation(s) in RCA: 42] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Cognitive resilience is often defined as the ability to remain cognitively normal in the face of insults to the brain. These insults can include disease pathology, such as plaques and tangles associated with Alzheimer's disease, stroke, traumatic brain injury, or other lesions. Factors such as physical or mental activity and genetics may contribute to cognitive resilience, but the neurobiological underpinnings remain ill-defined. Emerging evidence suggests that dendritic spine structural plasticity is one plausible mechanism. In this review, we highlight the basic structure and function of dendritic spines and discuss how spine density and morphology change in aging and Alzheimer's disease. We note evidence that spine plasticity mediates resilience to stress, and we tackle dendritic spines in the context of cognitive resilience to Alzheimer's disease. Finally, we examine how lifestyle and genetic factors may influence dendritic spine plasticity to promote cognitive resilience before discussing evidence for actin regulatory kinases as therapeutic targets for Alzheimer's disease.
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Affiliation(s)
- Courtney K. Walker
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
| | - Jeremy H. Herskowitz
- Center for Neurodegeneration and Experimental Therapeutics, Department of Neurology, University of Alabama at Birmingham, USA
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9
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Fischer TT, Nguyen LD, Ehrlich BE. Neuronal calcium sensor 1 (NCS1) dependent modulation of neuronal morphology and development. FASEB J 2021; 35:e21873. [PMID: 34499766 DOI: 10.1096/fj.202100731r] [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: 05/03/2021] [Revised: 07/24/2021] [Accepted: 08/09/2021] [Indexed: 12/14/2022]
Abstract
Calcium (Ca2+ ) signaling is critical for neuronal functioning and requires the concerted interplay of numerous Ca2+ -binding proteins, including neuronal calcium sensor 1 (NCS1). Although an important role of NCS1 in neuronal processes and in neurodevelopmental and neurodegenerative diseases has been established, the underlying mechanisms remain enigmatic. Here, we systematically investigated the functions of NCS1 in the brain. Using Golgi-Cox staining, we observed a reduction in dendritic complexity and spine density in the prefrontal cortex and the dorsal hippocampus of Ncs1-/- mice, which may underlie concomitantly observed deficits in memory acquisition. Subsequent RNA sequencing of Ncs1-/- and Ncs1+/+ mouse brain tissues revealed that NCS1 modulates gene expression related to neuronal morphology and development. Investigation of developmental databases further supported a molecular role of NCS1 during brain development by identifying temporal gene expression patterns. Collectively, this study provides insights into NCS1-dependent signaling and lays the foundation for a better understanding of NCS1-associated diseases.
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Affiliation(s)
- Tom T Fischer
- Department of Pharmacology, Yale University, New Haven, Connecticut, USA.,Institute of Pharmacology, Heidelberg University, Heidelberg, Germany
| | - Lien D Nguyen
- Department of Pharmacology, Yale University, New Haven, Connecticut, USA.,Interdepartmental Neuroscience Program, Yale University, New Haven, Connecticut, USA
| | - Barbara E Ehrlich
- Department of Pharmacology, Yale University, New Haven, Connecticut, USA.,Interdepartmental Neuroscience Program, Yale University, New Haven, Connecticut, USA.,Department of Celluar and Molecular Physiology, Yale University, New Haven, Connecticut, USA
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10
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LIM-Kinases in Synaptic Plasticity, Memory, and Brain Diseases. Cells 2021; 10:cells10082079. [PMID: 34440848 PMCID: PMC8391678 DOI: 10.3390/cells10082079] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 07/30/2021] [Accepted: 08/04/2021] [Indexed: 12/12/2022] Open
Abstract
Learning and memory require structural and functional modifications of synaptic connections, and synaptic deficits are believed to underlie many brain disorders. The LIM-domain-containing protein kinases (LIMK1 and LIMK2) are key regulators of the actin cytoskeleton by affecting the actin-binding protein, cofilin. In addition, LIMK1 is implicated in the regulation of gene expression by interacting with the cAMP-response element-binding protein. Accumulating evidence indicates that LIMKs are critically involved in brain function and dysfunction. In this paper, we will review studies on the roles and underlying mechanisms of LIMKs in the regulation of long-term potentiation (LTP) and depression (LTD), the most extensively studied forms of long-lasting synaptic plasticity widely regarded as cellular mechanisms underlying learning and memory. We will also discuss the involvement of LIMKs in the regulation of the dendritic spine, the structural basis of synaptic plasticity, and memory formation. Finally, we will discuss recent progress on investigations of LIMKs in neurological and mental disorders, including Alzheimer’s, Parkinson’s, Williams–Beuren syndrome, schizophrenia, and autism spectrum disorders.
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11
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Keller-Pinter A, Gyulai-Nagy S, Becsky D, Dux L, Rovo L. Syndecan-4 in Tumor Cell Motility. Cancers (Basel) 2021; 13:cancers13133322. [PMID: 34282767 PMCID: PMC8268284 DOI: 10.3390/cancers13133322] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 06/25/2021] [Accepted: 06/27/2021] [Indexed: 12/13/2022] Open
Abstract
Simple Summary Cell migration is crucial fReaor metastasis formation and a hallmark of malignancy. The primary cause of high mortality among oncology patients is the ability of cancer cells to metastasize. To form metastasis, primary tumor cells must be intrinsically able to move. The transmembrane, heparan sulfate proteoglycan syndecan-4 (SDC4) exhibits multiple functions in signal transduction by regulating Rac1 GTPase activity and consequently actin remodeling, as well as regulating focal adhesion kinase, protein kinase C-alpha and the level of intracellular calcium. By affecting several signaling pathways and biological processes, SDC4 is involved in cell migration under physiological and pathological conditions as well. In this review, we discuss the SDC4-mediated cell migration focusing on the role of SDC4 in tumor cell movement. Abstract Syndecan-4 (SDC4) is a ubiquitously expressed, transmembrane proteoglycan bearing heparan sulfate chains. SDC4 is involved in numerous inside-out and outside-in signaling processes, such as binding and sequestration of growth factors and extracellular matrix components, regulation of the activity of the small GTPase Rac1, protein kinase C-alpha, the level of intracellular calcium, or the phosphorylation of focal adhesion kinase. The ability of this proteoglycan to link the extracellular matrix and actin cytoskeleton enables SDC4 to contribute to biological functions like cell adhesion and migration, cell proliferation, cytokinesis, cellular polarity, or mechanotransduction. The multiple roles of SDC4 in tumor pathogenesis and progression has already been demonstrated; therefore, the expression and signaling of SDC4 was investigated in several tumor types. SDC4 influences tumor progression by regulating cell proliferation as well as cell migration by affecting cell-matrix adhesion and several signaling pathways. Here, we summarize the general role of SDC4 in cell migration and tumor cell motility.
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Affiliation(s)
- Aniko Keller-Pinter
- Department of Biochemistry, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (S.G.-N.); (D.B.); (L.D.)
- Correspondence:
| | - Szuzina Gyulai-Nagy
- Department of Biochemistry, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (S.G.-N.); (D.B.); (L.D.)
| | - Daniel Becsky
- Department of Biochemistry, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (S.G.-N.); (D.B.); (L.D.)
| | - Laszlo Dux
- Department of Biochemistry, Faculty of Medicine, University of Szeged, H-6720 Szeged, Hungary; (S.G.-N.); (D.B.); (L.D.)
| | - Laszlo Rovo
- Department of Oto-Rhino-Laryngology and Head-Neck Surgery, University of Szeged, H-6725 Szeged, Hungary;
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12
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Saneyoshi T. Reciprocal activation within a kinase effector complex: A mechanism for the persistence of molecular memory. Brain Res Bull 2021; 170:58-64. [PMID: 33556559 DOI: 10.1016/j.brainresbull.2021.01.018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 01/10/2021] [Accepted: 01/25/2021] [Indexed: 01/01/2023]
Abstract
Synaptic connections in neuronal circuits change in response to neuronal activity patterns. This can induce a persistent change in the efficacy of synaptic transmission, a phenomenon known as synaptic plasticity. One form of plasticity, long-term potentiation (LTP) has been extensively studied as the cellular basis of memory. In LTP, the potentiated synaptic transmission persists along with structural changes in the synapses. Many studies have sought to identify the "memory molecule" or the "molecular engram". Ca2+/calmodulin-dependent protein kinase II (CaMKII) is probably the most well-studied candidate for the memory molecule. However, consensus has not yet been reached on a very basic aspect: how CaMKII is regulated during LTP. Here, I propose a new model of CaMKII regulation: reciprocal activation within a kinase effector complex (RAKEC) that is made between CaMKII and its effector protein, which is mediated by a persistent interaction between CaMKII and a pseudosubstrate sequence on T-lymphoma invasion and metastasis protein 1 (Tiam1), resulting in reciprocal activation of these two molecules. Through the RAKEC mechanism, CaMKII can maintain memory as biochemical activity in a synapse-specific manner. In this review, the detailed mechanism of the RAKEC and its expansion for the maintenance of LTP is described.
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Affiliation(s)
- Takeo Saneyoshi
- Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan.
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13
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Ji B, Skup M. Roles of palmitoylation in structural long-term synaptic plasticity. Mol Brain 2021; 14:8. [PMID: 33430908 PMCID: PMC7802216 DOI: 10.1186/s13041-020-00717-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Accepted: 12/15/2020] [Indexed: 11/30/2022] Open
Abstract
Long-term potentiation (LTP) and long-term depression (LTD) are important cellular mechanisms underlying learning and memory processes. N-Methyl-d-aspartate receptor (NMDAR)-dependent LTP and LTD play especially crucial roles in these functions, and their expression depends on changes in the number and single channel conductance of the major ionotropic glutamate receptor α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR) located on the postsynaptic membrane. Structural changes in dendritic spines comprise the morphological platform and support for molecular changes in the execution of synaptic plasticity and memory storage. At the molecular level, spine morphology is directly determined by actin cytoskeleton organization within the spine and indirectly stabilized and consolidated by scaffold proteins at the spine head. Palmitoylation, as a uniquely reversible lipid modification with the ability to regulate protein membrane localization and trafficking, plays significant roles in the structural and functional regulation of LTP and LTD. Altered structural plasticity of dendritic spines is also considered a hallmark of neurodevelopmental disorders, while genetic evidence strongly links abnormal brain function to impaired palmitoylation. Numerous studies have indicated that palmitoylation contributes to morphological spine modifications. In this review, we have gathered data showing that the regulatory proteins that modulate the actin network and scaffold proteins related to AMPAR-mediated neurotransmission also undergo palmitoylation and play roles in modifying spine architecture during structural plasticity.
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Affiliation(s)
- Benjun Ji
- Nencki Institute of Experimental Biology, 02-093, Warsaw, Poland.
| | - Małgorzata Skup
- Nencki Institute of Experimental Biology, 02-093, Warsaw, Poland.
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14
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Sulistomo HW, Nemoto T, Kage Y, Fujii H, Uchida T, Takamiya K, Sumimoto H, Kataoka H, Bito H, Takeya R. Fhod3 Controls the Dendritic Spine Morphology of Specific Subpopulations of Pyramidal Neurons in the Mouse Cerebral Cortex. Cereb Cortex 2020; 31:2205-2219. [PMID: 33251537 DOI: 10.1093/cercor/bhaa355] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Revised: 10/27/2020] [Accepted: 10/28/2020] [Indexed: 01/25/2023] Open
Abstract
Changes in the shape and size of the dendritic spines are critical for synaptic transmission. These morphological changes depend on dynamic assembly of the actin cytoskeleton and occur differently in various types of neurons. However, how the actin dynamics are regulated in a neuronal cell type-specific manner remains largely unknown. We show that Fhod3, a member of the formin family proteins that mediate F-actin assembly, controls the dendritic spine morphogenesis of specific subpopulations of cerebrocortical pyramidal neurons. Fhod3 is expressed specifically in excitatory pyramidal neurons within layers II/III and V of restricted areas of the mouse cerebral cortex. Immunohistochemical and biochemical analyses revealed the accumulation of Fhod3 in postsynaptic spines. Although targeted deletion of Fhod3 in the brain did not lead to any defects in the gross or histological appearance of the brain, the dendritic spines in pyramidal neurons within presumptive Fhod3-positive areas were morphologically abnormal. In primary cultures prepared from the Fhod3-depleted cortex, defects in spine morphology were only detected in Fhod3 promoter-active cells, a small population of pyramidal neurons, and not in Fhod3 promoter-negative pyramidal neurons. Thus, Fhod3 plays a crucial role in dendritic spine morphogenesis only in a specific population of pyramidal neurons in a cell type-specific manner.
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Affiliation(s)
- Hikmawan Wahyu Sulistomo
- Department of Pharmacology, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Takayuki Nemoto
- Department of Pharmacology, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Yohko Kage
- Department of Pharmacology, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Hajime Fujii
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Taku Uchida
- Department of Integrative Physiology, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Kogo Takamiya
- Department of Integrative Physiology, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Hideki Sumimoto
- Department of Biochemistry, Kyushu University Graduate School of Medical Sciences, Fukuoka 812-8582, Japan
| | - Hiroaki Kataoka
- Department of Pathology, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
| | - Haruhiko Bito
- Department of Neurochemistry, Graduate School of Medicine, The University of Tokyo, Tokyo 113-0033, Japan
| | - Ryu Takeya
- Department of Pharmacology, Faculty of Medicine, University of Miyazaki, Miyazaki 889-1692, Japan
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15
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Lavanderos B, Silva I, Cruz P, Orellana-Serradell O, Saldías MP, Cerda O. TRP Channels Regulation of Rho GTPases in Brain Context and Diseases. Front Cell Dev Biol 2020; 8:582975. [PMID: 33240883 PMCID: PMC7683514 DOI: 10.3389/fcell.2020.582975] [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: 07/13/2020] [Accepted: 10/05/2020] [Indexed: 12/13/2022] Open
Abstract
Neurological and neuropsychiatric disorders are mediated by several pathophysiological mechanisms, including developmental and degenerative abnormalities caused primarily by disturbances in cell migration, structural plasticity of the synapse, and blood-vessel barrier function. In this context, critical pathways involved in the pathogenesis of these diseases are related to structural, scaffolding, and enzymatic activity-bearing proteins, which participate in Ca2+- and Ras Homologs (Rho) GTPases-mediated signaling. Rho GTPases are GDP/GTP binding proteins that regulate the cytoskeletal structure, cellular protrusion, and migration. These proteins cycle between GTP-bound (active) and GDP-bound (inactive) states due to their intrinsic GTPase activity and their dynamic regulation by GEFs, GAPs, and GDIs. One of the most important upstream inputs that modulate Rho GTPases activity is Ca2+ signaling, positioning ion channels as pivotal molecular entities for Rho GTPases regulation. Multiple non-selective cationic channels belonging to the Transient Receptor Potential (TRP) family participate in cytoskeletal-dependent processes through Ca2+-mediated modulation of Rho GTPases. Moreover, these ion channels have a role in several neuropathological events such as neuronal cell death, brain tumor progression and strokes. Although Rho GTPases-dependent pathways have been extensively studied, how they converge with TRP channels in the development or progression of neuropathologies is poorly understood. Herein, we review recent evidence and insights that link TRP channels activity to downstream Rho GTPase signaling or modulation. Moreover, using the TRIP database, we establish associations between possible mediators of Rho GTPase signaling with TRP ion channels. As such, we propose mechanisms that might explain the TRP-dependent modulation of Rho GTPases as possible pathways participating in the emergence or maintenance of neuropathological conditions.
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Affiliation(s)
- Boris Lavanderos
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Ian Silva
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Pablo Cruz
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Octavio Orellana-Serradell
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - María Paz Saldías
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile
| | - Oscar Cerda
- Program of Cellular and Molecular Biology, Institute of Biomedical Sciences, Faculty of Medicine, Universidad de Chile, Santiago, Chile.,Millennium Nucleus of Ion Channel-Associated Diseases (MiNICAD), Santiago, Chile.,The Wound Repair, Treatment and Health (WoRTH) Initiative, Santiago, Chile
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16
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Kolyvushko O, Kelch MA, Osterrieder N, Azab W. Equine Alphaherpesviruses Require Activation of the Small GTPases Rac1 and Cdc42 for Intracellular Transport. Microorganisms 2020; 8:microorganisms8071013. [PMID: 32645930 PMCID: PMC7409331 DOI: 10.3390/microorganisms8071013] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 07/01/2020] [Accepted: 07/03/2020] [Indexed: 12/14/2022] Open
Abstract
Viruses utilize host cell signaling to facilitate productive infection. Equine herpesvirus type 1 (EHV-1) has been shown to activate Ca2+ release and phospholipase C upon contact with α4β1 integrins on the cell surface. Signaling molecules, including small GTPases, have been shown to be activated downstream of Ca2+ release, and modulate virus entry, membrane remodeling and intracellular transport. In this study, we show that EHV-1 activates the small GTPases Rac1 and Cdc42 during infection. The activation of Rac1 and Cdc42 is necessary for virus-induced acetylation of tubulin, effective viral transport to the nucleus, and cell-to-cell spread. We also show that inhibitors of Rac1 and Cdc42 did not block virus entry, but inhibited overall virus infection. The Rac1 and Cdc42 signaling is presumably orthogonal to Ca2+ release, since Rac1 and Cdc42 inhibitors affected the infection of both EHV-1 and EHV-4, which do not bind to integrins.
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Affiliation(s)
| | | | | | - Walid Azab
- Correspondence: ; Tel.: +49-30-838-50087
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17
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Miyata T, Kikuchi K, Ihara D, Kaito M, Ishibashi Y, Hakamata T, Yamada T, Ishikawa M, Mizukoshi M, Shoji S, Fukuchi M, Tsuda M, Hida Y, Ohtsuka T, Kaneda M, Tabuchi A. Neuron-enriched phosphatase and actin regulator 3 (Phactr3)/ nuclear scaffold-associated PP1-inhibiting protein (Scapinin) regulates dendritic morphology via its protein phosphatase 1-binding domain. Biochem Biophys Res Commun 2020; 528:322-329. [DOI: 10.1016/j.bbrc.2020.05.006] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 05/01/2020] [Indexed: 02/06/2023]
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18
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Artificial Intelligence and the detection of pediatric concussion using epigenomic analysis. Brain Res 2019; 1726:146510. [PMID: 31628932 DOI: 10.1016/j.brainres.2019.146510] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2019] [Revised: 10/14/2019] [Accepted: 10/15/2019] [Indexed: 12/12/2022]
Abstract
Concussion, also referred to as mild traumatic brain injury (mTBI) is the most common type of traumatic brain injury. Currently concussion is an area ofintensescientific interest to better understand the biological mechanisms and for biomarker development. We evaluated whole genome-wide blood DNA cytosine ('CpG') methylation in 17 pediatric concussion isolated cases and 18 unaffected controls using Illumina Infinium MethylationEPIC assay. Pathway analysis was performed using Ingenuity Pathway Analysis to help elucidate the epigenetic and molecular mechanisms of the disorder. Area under the receiver operating characteristics (AUC) curves and FDR p-values were calculated for mTBI detection based on CpG methylation levels. Multiple Artificial Intelligence (AI) platforms including Deep Learning (DL), the newest form of AI, were used to predict concussion based on i) CpG methylation markers alone, and ii) combined epigenetic, clinical and demographic predictors. We found 449 CpG sites (473 genes), those were statistically significantly methylated in mTBI compared to controls. There were four CpGs with excellent individual accuracy (AUC ≥ 0.90-1.00) while 119 displayed good accuracy (AUC ≥ 0.80-0.89) for the prediction of mTBI. The CpG methylation changes ≥10% were observed in many CpG loci after concussion suggesting biological significance. Pathway analysis identified several biologically important neurological pathways that were perturbed including those associated with: impaired brain function, cognition, memory, neurotransmission, intellectual disability and behavioral change and associated disorders. The combination of epigenomic and clinical predictors were highly accurate for the detection of concusion using AI techniques. Using DL/AI, a combination of epigenomic and clinical markers had sensitivity and specificity ≧95% for prediction of mTBI. In this novel study, we identified significant methylation changes in multiple genes in response to mTBI. Gene pathways that were epigenetically dysregulated included several known to be involved in neurological function, thus giving biological plausibility to our findings.
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19
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Saneyoshi T, Matsuno H, Suzuki A, Murakoshi H, Hedrick NG, Agnello E, O'Connell R, Stratton MM, Yasuda R, Hayashi Y. Reciprocal Activation within a Kinase-Effector Complex Underlying Persistence of Structural LTP. Neuron 2019; 102:1199-1210.e6. [PMID: 31078368 DOI: 10.1016/j.neuron.2019.04.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2018] [Revised: 12/07/2018] [Accepted: 04/03/2019] [Indexed: 10/26/2022]
Abstract
Long-term synaptic plasticity requires a mechanism that converts short Ca2+ pulses into persistent biochemical signaling to maintain changes in the synaptic structure and function. Here, we present a novel mechanism of a positive feedback loop, formed by a reciprocally activating kinase-effector complex (RAKEC) in dendritic spines, enabling the persistence and confinement of a molecular memory. We found that stimulation of a single spine causes the rapid formation of a RAKEC consisting of CaMKII and Tiam1, a Rac-GEF. This interaction is mediated by a pseudo-autoinhibitory domain on Tiam1, which is homologous to the CaMKII autoinhibitory domain itself. Therefore, Tiam1 binding results in constitutive CaMKII activation, which in turn persistently phosphorylates Tiam1. Phosphorylated Tiam1 promotes stable actin-polymerization through Rac1, thereby maintaining the structure of the spine during LTP. The RAKEC can store biochemical information in small subcellular compartments, thus potentially serving as a general mechanism for prolonged and compartmentalized signaling.
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Affiliation(s)
- Takeo Saneyoshi
- Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan; Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan.
| | - Hitomi Matsuno
- Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan
| | - Akio Suzuki
- Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan
| | - Hideji Murakoshi
- National Institute of Physiological Science, Okazaki, Aichi 444-8585, Japan; Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458, USA; Duke University Medical Center, Durham, NC 27703, USA
| | - Nathan G Hedrick
- Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458, USA; Duke University Medical Center, Durham, NC 27703, USA
| | - Emily Agnello
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Rory O'Connell
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Margaret M Stratton
- Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, MA 01003, USA
| | - Ryohei Yasuda
- Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458, USA
| | - Yasunori Hayashi
- Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan; Department of Pharmacology, Kyoto University Graduate School of Medicine, Kyoto 606-8501, Japan; Brain and Body System Science Institute, Saitama University, Saitama 338-8570, Japan; School of Life Science, South China Normal University, Guangzhou 510631, China.
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20
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From membrane receptors to protein synthesis and actin cytoskeleton: Mechanisms underlying long lasting forms of synaptic plasticity. Semin Cell Dev Biol 2019; 95:120-129. [PMID: 30634048 DOI: 10.1016/j.semcdb.2019.01.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Revised: 01/07/2019] [Accepted: 01/08/2019] [Indexed: 12/13/2022]
Abstract
Synaptic plasticity, the activity dependent change in synaptic strength, forms the molecular foundation of learning and memory. Synaptic plasticity includes structural changes, with spines changing their size to accomodate insertion and removal of postynaptic receptors, which are correlated with functional changes. Of particular relevance for memory storage are the long lasting forms of synaptic plasticity which are protein synthesis dependent. Due to the importance of spine structural plasticity and protein synthesis, this review focuses on the signaling pathways that connect synaptic stimulation with regulation of protein synthesis and remodeling of the actin cytoskeleton. We also review computational models that implement novel aspects of molecular signaling in synaptic plasticity, such as the role of neuromodulators and spatial microdomains, as well as highlight the need for computational models that connect activation of memory kinases with spine actin dynamics.
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21
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Shin MS, Song SH, Shin JE, Lee SH, Huh SO, Park D. Src-mediated phosphorylation of βPix-b regulates dendritic spine morphogenesis. J Cell Sci 2019; 132:jcs.224980. [DOI: 10.1242/jcs.224980] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 12/24/2018] [Indexed: 11/20/2022] Open
Abstract
PAK-interacting guanine nucleotide exchange factor (βPix) has been implicated in many actin-based cellular processes including spine morphogenesis in neurons. However, the molecular mechanisms by which βPix controls spine morphology remain elusive. Previously, we have reported the expression of several alternative spliced βPix isoforms in the brain. Here, we report a novel finding that the b isoform of βPix (βPix-b) mediates regulation of spine and synapse formation. We found that βPix-b, which is mainly expressed in neurons, enhances spine and synapse formation through preferential localization at spines. In neurons, glutamate treatment efficiently stimulates Rac1 GEF activity of βPix-b. The glutamate stimulation also promotes Src kinase-mediated phosphorylation of βPix-b in both AMPA receptor- and NMDA receptor-dependent manner. Tyrosine 598 (Y598) of βPix-b is identified as the major Src-mediated phosphorylation site. Finally, Y598 phosphorylation of βPix-b enhances its Rac1 GEF activity that is critical for spine and synapse formation. In conclusion, we provide a novel mechanism by which βPix-b regulates activity-dependent spinogenesis and synaptogenesis via Src-mediated phosphorylation.
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Affiliation(s)
- Mi-seon Shin
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Sang-ho Song
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
- Current address: Lee Kong Chian School of Medicine, Nanyang Technological University and Institute of Molecular and Cell Biology, Singapore 138673, Singapore
| | - Jung Eun Shin
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
- Current address: KU Advanced Graduate Program for Life Science, Korea University, Seoul 02841, Republic of Korea
| | - Seung-Hye Lee
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
- Current address: Department of Neuroscience, Genentech, Inc., South San Francisco, CA 94080, USA
| | - Sung-Oh Huh
- Department of Pharmacology, College of Medicine, Institute of Natural Medicine, Hallym University, Chuncheon 24252, Republic of Korea
| | - Dongeun Park
- School of Biological Sciences, Seoul National University, Seoul 08826, Republic of Korea
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22
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Nicole O, Bell DM, Leste-Lasserre T, Doat H, Guillemot F, Pacary E. A novel role for CAMKIIβ in the regulation of cortical neuron migration: implications for neurodevelopmental disorders. Mol Psychiatry 2018; 23:2209-2226. [PMID: 29712998 PMCID: PMC6129389 DOI: 10.1038/s41380-018-0046-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2017] [Revised: 02/11/2018] [Accepted: 02/28/2018] [Indexed: 12/19/2022]
Abstract
Perturbation of CaMKIIβ expression has been associated with multiple neuropsychiatric diseases, highlighting CaMKIIβ as a gene of interest. Yet, in contrast to CaMKIIα, the specific functions of CaMKIIβ in the brain remain poorly explored. Here, we reveal a novel function for this CaMKII isoform in vivo during neuronal development. By using in utero electroporation, we show that CaMKIIβ is an important regulator of radial migration of projection neurons during cerebral cortex development. Knockdown of CaMKIIβ causes accelerated migration of nascent pyramidal neurons, whereas overexpression of CaMKIIβ inhibits migration, demonstrating that precise regulation of CaMKIIβ expression is required for correct neuronal migration. More precisely, CaMKIIβ controls the multipolar-bipolar transition in the intermediate zone and locomotion in the cortical plate through its actin-binding and -bundling activities. In addition, our data indicate that a fine-tuned balance between CaMKIIβ and cofilin activities is necessary to ensure proper migration of cortical neurons. Thus, our findings define a novel isoform-specific function for CaMKIIβ, demonstrating that CaMKIIβ has a major biological function in the developing brain.
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Affiliation(s)
- Olivier Nicole
- CNRS, UMR5293, Institut des Maladies Neurodégénératives, F-33000 Bordeaux, France,Université de Bordeaux, F-33000 Bordeaux, France
| | - Donald M. Bell
- Confocal and Image Analysis Facility, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | | | - Hélène Doat
- Transcriptome Facility, INSERM U1215, Neurocentre Magendie, F-33000 Bordeaux, France
| | | | - Emilie Pacary
- Université de Bordeaux, F-33000, Bordeaux, France. .,INSERM U1215, Neurocentre Magendie, F-33000, Bordeaux, France.
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23
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Chen Y, Milenkovic M, Horsfall W, Salahpour A, Soderling SH, Ramsey AJ. Restoring striatal WAVE-1 improves maze exploration performance of GluN1 knockdown mice. PLoS One 2018; 13:e0199341. [PMID: 30352064 PMCID: PMC6198945 DOI: 10.1371/journal.pone.0199341] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Accepted: 10/06/2018] [Indexed: 11/19/2022] Open
Abstract
NMDA receptors are important for cognition and are implicated in neuropsychiatric disorders. GluN1 knockdown (GluN1KD) mice have reduced NMDA receptor levels, striatal spine density deficits, and cognitive impairments. However, how NMDA depletion leads to these effects is unclear. Since Rho GTPases are known to regulate spine density and cognition, we examined the levels of RhoA, Rac1, and Cdc42 signaling proteins. Striatal Rac1-pathway components are reduced in GluN1KD mice, with Rac1 and WAVE-1 deficits at 6 and 12 weeks of age. Concurrently, medium spiny neuron (MSN) spine density deficits are present in mice at these ages. To determine whether WAVE-1 deficits were causal or compensatory in relation to these phenotypes, we intercrossed GluN1KD mice with WAVE-1 overexpressing (WAVE-Tg) mice to restore WAVE-1 levels. GluN1KD-WAVE-Tg hybrids showed rescue of striatal WAVE-1 protein levels and MSN spine density, as well as selective behavioral rescue in the Y-maze and 8-arm radial maze tests. GluN1KD-WAVE-Tg mice expressed normalized WAVE-1 protein levels in the hippocampus, yet spine density of hippocampal CA1 pyramidal neurons was not significantly altered. Our data suggest a nuanced role for WAVE-1 effects on cognition and a delineation of specific cognitive domains served by the striatum. Rescue of striatal WAVE-1 and MSN spine density may be significant for goal-directed exploration and associated long-term memory in mice.
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Affiliation(s)
- Yuxiao Chen
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - Marija Milenkovic
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - Wendy Horsfall
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - Ali Salahpour
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
| | - Scott H. Soderling
- Department of Cell Biology, Duke University Medical Center, Durham, NC, United States of America
| | - Amy J. Ramsey
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON, Canada
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24
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Ueda Y, Sato M. Induction of Signal Transduction by Using Non-Channelrhodopsin-Type Optogenetic Tools. Chembiochem 2018; 19:1217-1231. [PMID: 29577530 DOI: 10.1002/cbic.201700635] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Indexed: 12/24/2022]
Abstract
Signal transductions are the basis for all cellular functions. Previous studies investigating signal transductions mainly relied on pharmacological inhibition, RNA interference, and constitutive active/dominant negative protein expression systems. However, such studies do not allow the modulation of protein activity with high spatial and temporal precision in cells, tissues, and organs in animals. Recently, non-channelrhodopsin-type optogenetic tools for regulating signal transduction have emerged. These photoswitches address several disadvantages of previous techniques, and allow us to control a variety of signal transductions such as cell membrane dynamics, calcium signaling, lipid signaling, and apoptosis. In this review we summarize recent advances in the development of such photoswitches and in how these optotools are applied to signaling processes.
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Affiliation(s)
- Yoshibumi Ueda
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan
- AMED-PRIME (Japan), Agency for Medical Research and Development, Tokyo, Japan
| | - Moritoshi Sato
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902, Japan
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Acevedo A, González-Billault C. Crosstalk between Rac1-mediated actin regulation and ROS production. Free Radic Biol Med 2018; 116:101-113. [PMID: 29330095 DOI: 10.1016/j.freeradbiomed.2018.01.008] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Revised: 01/03/2018] [Accepted: 01/05/2018] [Indexed: 02/08/2023]
Abstract
The small RhoGTPase Rac1 is implicated in a variety of events related to actin cytoskeleton rearrangement. Remarkably, another event that is completely different from those related to actin regulation has the same relevance; the Rac1-mediated production of reactive oxygen species (ROS) through NADPH oxidases (NOX). Each outcome involves different Rac1 downstream effectors; on one hand, events related to the actin cytoskeleton require Rac1 to bind to WAVEs proteins and PAKs that ultimately promote actin branching and turnover, on the other, NOX-derived ROS production demands active Rac1 to be bound to a cytosolic activator of NOX. How Rac1-mediated signaling ends up promoting actin-related events, NOX-derived ROS, or both is poorly understood. Rac1 regulators, including scaffold proteins, are known to exert tight control over its functions. Hence, evidence of Rac1 regulatory events leading to both actin remodeling and NOX-mediated ROS generation are discussed. Moreover, cellular functions linked to physiological and pathological conditions that exhibit crosstalk between Rac1 outcomes are analyzed, while plausible roles in neuronal functions (and dysfunctions) are highlighted. Together, discussed evidence shed light on cellular mechanisms which requires Rac1 to direct either actin- and/or ROS-related events, helping to understand crucial roles of Rac1 dual functionality.
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Affiliation(s)
- Alejandro Acevedo
- FONDAP Geroscience Center for Brain Health and Metabolism, Santiago, Chile.
| | - Christian González-Billault
- FONDAP Geroscience Center for Brain Health and Metabolism, Santiago, Chile; Department of Biology, Faculty of Sciences, Universidad de Chile, 7800024, Chile; The Buck Institute for Research on Aging, Novato, USA.
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Synaptic localisation of SRF coactivators, MKL1 and MKL2, and their role in dendritic spine morphology. Sci Rep 2018; 8:727. [PMID: 29335431 PMCID: PMC5768758 DOI: 10.1038/s41598-017-18905-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2017] [Accepted: 12/15/2017] [Indexed: 01/01/2023] Open
Abstract
The megakaryoblastic leukaemia (MKL) family are serum response factor (SRF) coactivators, which are highly expressed in the brain. Accordingly, MKL plays important roles in dendritic morphology, neuronal migration, and brain development. Further, nucleotide substitutions in the MKL1 and MKL2 genes are found in patients with schizophrenia and autism spectrum disorder, respectively. Thus, studies on the precise synaptic localisation and function of MKL in neurons are warranted. In this study, we generated and tested new antibodies that specifically recognise endogenously expressed MKL1 and MKL2 proteins in neurons. Using these reagents, we biochemically and immunocytochemically show that MKL1 and MKL2 are localised at synapses. Furthermore, shRNA experiments revealed that postsynaptic deletion of MKL1 or MKL2 reduced the percentage of mushroom- or stubby-type spines in cultured neurons. Taken together, our findings suggest that MKL1 and MKL2 are present at synapses and involved in dendritic spine maturation. This study may, at least in part, contribute to better understanding of the molecular mechanisms underlying MKL-mediated synaptic plasticity and neurological disorders.
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Wigerius M, Quinn D, Diab A, Clattenburg L, Kolar A, Qi J, Krueger SR, Fawcett JP. The polarity protein Angiomotin p130 controls dendritic spine maturation. J Cell Biol 2018; 217:715-730. [PMID: 29317530 PMCID: PMC5800806 DOI: 10.1083/jcb.201705184] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Revised: 10/31/2017] [Accepted: 11/30/2017] [Indexed: 01/06/2023] Open
Abstract
Wigerius et al. identify the polarity protein AMOT-130 as vital for dendritic spine morphogenesis. They show that reduced Lats1 kinase activity in the neonatal brain is required for the recruitment of AMOT-130 to postsynaptic compartments to stabilize dendritic spines. The actin cytoskeleton is essential for the structural changes in dendritic spines that lead to the formation of new synapses. Although the molecular mechanisms underlying spine formation are well characterized, the events that drive spine maturation during development are largely unknown. In this study, we demonstrate that Angiomotin (AMOT-130) is necessary for spine stabilization. AMOT-130 is enriched in mature dendritic spines and functions to stabilize the actin cytoskeleton by coupling F-actin to postsynaptic protein scaffolds. These functions of AMOT are transiently restricted during postnatal development by phosphorylation imposed by the kinase Lats1. Our study proposes that AMOT-130 is essential for normal spine morphogenesis and identifies Lats1 as an upstream regulator in this process. Moreover, our findings may link AMOT-130 loss and the related spine defects to neurological disorders.
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Affiliation(s)
- Michael Wigerius
- Department of Pharmacology, Dalhousie University, Halifax, Canada
| | - Dylan Quinn
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Canada
| | - Antonios Diab
- Department of Pharmacology, Dalhousie University, Halifax, Canada
| | | | - Annette Kolar
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Canada
| | - Jiansong Qi
- Department of Pharmacology, Dalhousie University, Halifax, Canada
| | - Stefan R Krueger
- Department of Physiology and Biophysics, Dalhousie University, Halifax, Canada
| | - James P Fawcett
- Department of Pharmacology, Dalhousie University, Halifax, Canada .,Department of Surgery, Dalhousie University, Halifax, Canada
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Dombert B, Balk S, Lüningschrör P, Moradi M, Sivadasan R, Saal-Bauernschubert L, Jablonka S. BDNF/trkB Induction of Calcium Transients through Ca v2.2 Calcium Channels in Motoneurons Corresponds to F-actin Assembly and Growth Cone Formation on β2-Chain Laminin (221). Front Mol Neurosci 2017; 10:346. [PMID: 29163025 PMCID: PMC5670157 DOI: 10.3389/fnmol.2017.00346] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 10/12/2017] [Indexed: 12/11/2022] Open
Abstract
Spontaneous Ca2+ transients and actin dynamics in primary motoneurons correspond to cellular differentiation such as axon elongation and growth cone formation. Brain-derived neurotrophic factor (BDNF) and its receptor trkB support both motoneuron survival and synaptic differentiation. However, in motoneurons effects of BDNF/trkB signaling on spontaneous Ca2+ influx and actin dynamics at axonal growth cones are not fully unraveled. In our study we addressed the question how neurotrophic factor signaling corresponds to cell autonomous excitability and growth cone formation. Primary motoneurons from mouse embryos were cultured on the synapse specific, β2-chain containing laminin isoform (221) regulating axon elongation through spontaneous Ca2+ transients that are in turn induced by enhanced clustering of N-type specific voltage-gated Ca2+ channels (Cav2.2) in axonal growth cones. TrkB-deficient (trkBTK-/-) mouse motoneurons which express no full-length trkB receptor and wildtype motoneurons cultured without BDNF exhibited reduced spontaneous Ca2+ transients that corresponded to altered axon elongation and defects in growth cone morphology which was accompanied by changes in the local actin cytoskeleton. Vice versa, the acute application of BDNF resulted in the induction of spontaneous Ca2+ transients and Cav2.2 clustering in motor growth cones, as well as the activation of trkB downstream signaling cascades which promoted the stabilization of β-actin via the LIM kinase pathway and phosphorylation of profilin at Tyr129. Finally, we identified a mutual regulation of neuronal excitability and actin dynamics in axonal growth cones of embryonic motoneurons cultured on laminin-221/211. Impaired excitability resulted in dysregulated axon extension and local actin cytoskeleton, whereas upon β-actin knockdown Cav2.2 clustering was affected. We conclude from our data that in embryonic motoneurons BDNF/trkB signaling contributes to axon elongation and growth cone formation through changes in the local actin cytoskeleton accompanied by increased Cav2.2 clustering and local calcium transients. These findings may help to explore cellular mechanisms which might be dysregulated during maturation of embryonic motoneurons leading to motoneuron disease.
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Affiliation(s)
- Benjamin Dombert
- Institute of Clinical Neurobiology, University of Wuerzburg, Wuerzburg, Germany
| | - Stefanie Balk
- Institute of Clinical Neurobiology, University of Wuerzburg, Wuerzburg, Germany
| | | | - Mehri Moradi
- Institute of Clinical Neurobiology, University of Wuerzburg, Wuerzburg, Germany
| | - Rajeeve Sivadasan
- Institute of Clinical Neurobiology, University of Wuerzburg, Wuerzburg, Germany
| | | | - Sibylle Jablonka
- Institute of Clinical Neurobiology, University of Wuerzburg, Wuerzburg, Germany
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29
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Kikuchi K, Shiota J, Yamada T, Ishikawa M, Ihara D, Fukuchi M, Tsuda M, Tabuchi A. Rho signaling inhibitor, CCG-1423, inhibits axonal elongation and dendritic complexity of rat cortical neurons. Biochem Biophys Res Commun 2017; 492:474-479. [DOI: 10.1016/j.bbrc.2017.08.071] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 08/18/2017] [Indexed: 10/19/2022]
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Szkop KJ, Cooke PIC, Humphries JA, Kalna V, Moss DS, Schuster EF, Nobeli I. Dysregulation of Alternative Poly-adenylation as a Potential Player in Autism Spectrum Disorder. Front Mol Neurosci 2017; 10:279. [PMID: 28955198 PMCID: PMC5601403 DOI: 10.3389/fnmol.2017.00279] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2017] [Accepted: 08/17/2017] [Indexed: 11/30/2022] Open
Abstract
We present here the hypothesis that alternative poly-adenylation (APA) is dysregulated in the brains of individuals affected by Autism Spectrum Disorder (ASD), due to disruptions in the calcium signaling networks. APA, the process of selecting different poly-adenylation sites on the same gene, yielding transcripts with different-length 3′ untranslated regions (UTRs), has been documented in different tissues, stages of development and pathologic conditions. Differential use of poly-adenylation sites has been shown to regulate the function, stability, localization and translation efficiency of target RNAs. However, the role of APA remains rather unexplored in neurodevelopmental conditions. In the human brain, where transcripts have the longest 3′ UTRs and are thus likely to be under more complex post-transcriptional regulation, erratic APA could be particularly detrimental. In the context of ASD, a condition that affects individuals in markedly different ways and whose symptoms exhibit a spectrum of severity, APA dysregulation could be amplified or dampened depending on the individual and the extent of the effect on specific genes would likely vary with genetic and environmental factors. If this hypothesis is correct, dysregulated APA events might be responsible for certain aspects of the phenotypes associated with ASD. Evidence supporting our hypothesis is derived from standard RNA-seq transcriptomic data but we suggest that future experiments should focus on techniques that probe the actual poly-adenylation site (3′ sequencing). To address issues arising from the use of post-mortem tissue and low numbers of heterogeneous samples affected by confounding factors (such as the age, gender and health of the individuals), carefully controlled in vitro systems will be required to model the effect of calcium signaling dysregulation in the ASD brain.
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Affiliation(s)
- Krzysztof J Szkop
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of LondonLondon, United Kingdom
| | - Peter I C Cooke
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of LondonLondon, United Kingdom
| | - Joanne A Humphries
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of LondonLondon, United Kingdom
| | - Viktoria Kalna
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of LondonLondon, United Kingdom
| | - David S Moss
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of LondonLondon, United Kingdom
| | | | - Irene Nobeli
- Department of Biological Sciences, Institute of Structural and Molecular Biology, Birkbeck, University of LondonLondon, United Kingdom
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31
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Abstract
Memory is an adaptation to particular temporal properties of past events, such as the frequency of occurrence of a stimulus or the coincidence of multiple stimuli. In neurons, this adaptation can be understood in terms of a hierarchical system of molecular and cellular time windows, which collectively retain information from the past. We propose that this system makes various timescales of past experience simultaneously available for future adjustment of behavior. More generally, we propose that the ability to detect and respond to temporally structured information underlies the nervous system's capacity to encode and store a memory at molecular, cellular, synaptic, and circuit levels.
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Affiliation(s)
| | - Thomas James Carew
- Center for Neural Science, New York University, 4 Washington Place, New York, NY 10003, USA.
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32
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Ripoli C. Engrampigenetics: Epigenetics of engram memory cells. Behav Brain Res 2017; 325:297-302. [DOI: 10.1016/j.bbr.2016.11.043] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 11/24/2016] [Accepted: 11/26/2016] [Indexed: 12/21/2022]
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Hamilton AM, Lambert JT, Parajuli LK, Vivas O, Park DK, Stein IS, Jahncke JN, Greenberg ME, Margolis SS, Zito K. A dual role for the RhoGEF Ephexin5 in regulation of dendritic spine outgrowth. Mol Cell Neurosci 2017; 80:66-74. [PMID: 28185854 DOI: 10.1016/j.mcn.2017.02.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Revised: 02/01/2017] [Accepted: 02/04/2017] [Indexed: 12/28/2022] Open
Abstract
The outgrowth of new dendritic spines is closely linked to the formation of new synapses, and is thought to be a vital component of the experience-dependent circuit plasticity that supports learning. Here, we examined the role of the RhoGEF Ephexin5 in driving activity-dependent spine outgrowth. We found that reducing Ephexin5 levels increased spine outgrowth, and increasing Ephexin5 levels decreased spine outgrowth in a GEF-dependent manner, suggesting that Ephexin5 acts as an inhibitor of spine outgrowth. Notably, we found that increased neural activity led to a proteasome-dependent reduction in the levels of Ephexin5 in neuronal dendrites, which could facilitate the enhanced spine outgrowth observed following increased neural activity. Surprisingly, we also found that Ephexin5-GFP levels were elevated on the dendrite at sites of future new spines, prior to new spine outgrowth. Moreover, lowering neuronal Ephexin5 levels inhibited new spine outgrowth in response to both global increases in neural activity and local glutamatergic stimulation of the dendrite, suggesting that Ephexin5 is necessary for activity-dependent spine outgrowth. Our data support a model in which Ephexin5 serves a dual role in spinogenesis, acting both as a brake on overall spine outgrowth and as a necessary component in the site-specific formation of new spines.
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Affiliation(s)
- A M Hamilton
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - J T Lambert
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - L K Parajuli
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - O Vivas
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - D K Park
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - I S Stein
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - J N Jahncke
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA
| | - M E Greenberg
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - S S Margolis
- Department of Biological Chemistry, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - K Zito
- Center for Neuroscience, University of California Davis, Davis, CA 95618, USA.
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34
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Lin YC, Frei JA, Kilander MBC, Shen W, Blatt GJ. A Subset of Autism-Associated Genes Regulate the Structural Stability of Neurons. Front Cell Neurosci 2016; 10:263. [PMID: 27909399 PMCID: PMC5112273 DOI: 10.3389/fncel.2016.00263] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Accepted: 10/28/2016] [Indexed: 12/15/2022] Open
Abstract
Autism spectrum disorder (ASD) comprises a range of neurological conditions that affect individuals’ ability to communicate and interact with others. People with ASD often exhibit marked qualitative difficulties in social interaction, communication, and behavior. Alterations in neurite arborization and dendritic spine morphology, including size, shape, and number, are hallmarks of almost all neurological conditions, including ASD. As experimental evidence emerges in recent years, it becomes clear that although there is broad heterogeneity of identified autism risk genes, many of them converge into similar cellular pathways, including those regulating neurite outgrowth, synapse formation and spine stability, and synaptic plasticity. These mechanisms together regulate the structural stability of neurons and are vulnerable targets in ASD. In this review, we discuss the current understanding of those autism risk genes that affect the structural connectivity of neurons. We sub-categorize them into (1) cytoskeletal regulators, e.g., motors and small RhoGTPase regulators; (2) adhesion molecules, e.g., cadherins, NCAM, and neurexin superfamily; (3) cell surface receptors, e.g., glutamatergic receptors and receptor tyrosine kinases; (4) signaling molecules, e.g., protein kinases and phosphatases; and (5) synaptic proteins, e.g., vesicle and scaffolding proteins. Although the roles of some of these genes in maintaining neuronal structural stability are well studied, how mutations contribute to the autism phenotype is still largely unknown. Investigating whether and how the neuronal structure and function are affected when these genes are mutated will provide insights toward developing effective interventions aimed at improving the lives of people with autism and their families.
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Affiliation(s)
- Yu-Chih Lin
- Laboratory of Neuronal Connectivity, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
| | - Jeannine A Frei
- Laboratory of Neuronal Connectivity, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
| | - Michaela B C Kilander
- Laboratory of Neuronal Connectivity, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
| | - Wenjuan Shen
- Laboratory of Neuronal Connectivity, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
| | - Gene J Blatt
- Laboratory of Autism Neurocircuitry, Program in Neuroscience, Hussman Institute for Autism, Baltimore MD, USA
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35
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Talking to the neighbours: The molecular and physiological mechanisms of clustered synaptic plasticity. Neurosci Biobehav Rev 2016; 71:352-361. [PMID: 27659124 DOI: 10.1016/j.neubiorev.2016.09.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/15/2016] [Accepted: 09/18/2016] [Indexed: 11/23/2022]
Abstract
Synaptic connectivity forms the basis for neuronal communication and the storage of information. Experiences and learning of new abilities can drive remodelling of this connectivity and promotes the formation of spine clusters; dendritic segments with a higher spine density. Spines located within these segments are frequently co-activated, undergo different dynamics than synapses located outside of this dendritic compartment and have, in general, a longer lifetime. Several lines of evidence have shown that chemical synapses located close to each other share or compete for intracellular signalling molecules and structural resources. This sharing and competition directly influences spine dynamics. Spines can grow, shrink, increase or decrease the surface expression of receptors, channels and adhesion molecules or remain stable and unchanged over extended periods of time. Here we summarize recent discoveries and provide a closer look at spine clustering, dendritic segment-specific signalling and potential molecular mechanisms underlying associative and heterosynaptic plasticity.
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36
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Chazeau A, Giannone G. Organization and dynamics of the actin cytoskeleton during dendritic spine morphological remodeling. Cell Mol Life Sci 2016; 73:3053-73. [PMID: 27105623 PMCID: PMC11108290 DOI: 10.1007/s00018-016-2214-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 03/31/2016] [Accepted: 03/31/2016] [Indexed: 12/18/2022]
Abstract
In the central nervous system, most excitatory post-synapses are small subcellular structures called dendritic spines. Their structure and morphological remodeling are tightly coupled to changes in synaptic transmission. The F-actin cytoskeleton is the main driving force of dendritic spine remodeling and sustains synaptic plasticity. It is therefore essential to understand how changes in synaptic transmission can regulate the organization and dynamics of actin binding proteins (ABPs). In this review, we will provide a detailed description of the organization and dynamics of F-actin and ABPs in dendritic spines and will discuss the current models explaining how the actin cytoskeleton sustains both structural and functional synaptic plasticity.
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Affiliation(s)
- Anaël Chazeau
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, UMR 5297, 33000, Bordeaux, France
- Interdisciplinary Institute for Neuroscience, CNRS, UMR 5297, 33000, Bordeaux, France
- Cell Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Grégory Giannone
- Interdisciplinary Institute for Neuroscience, University of Bordeaux, UMR 5297, 33000, Bordeaux, France.
- Interdisciplinary Institute for Neuroscience, CNRS, UMR 5297, 33000, Bordeaux, France.
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37
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Jedlicka P, Deller T. Understanding the role of synaptopodin and the spine apparatus in Hebbian synaptic plasticity - New perspectives and the need for computational modeling. Neurobiol Learn Mem 2016; 138:21-30. [PMID: 27470091 DOI: 10.1016/j.nlm.2016.07.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 07/15/2016] [Accepted: 07/23/2016] [Indexed: 12/17/2022]
Abstract
Synaptopodin (SP) is a proline-rich actin-associated protein essential for the formation of a spine apparatus (SA) in dendritic spines. The SA consists of stacks of smooth endoplasmic reticulum (sER) contiguous with the meshwork of somatodendritic ER. Spines of SP-deficient mice contain sER but no SA, demonstrating that SP is necessary for the assembly of ER cisterns into the more complex SA organelle. Although the SA was described decades ago, its function was difficult to investigate and remained elusive, in part because reliable markers for the SA were missing. After SP was identified as an essential component and a reliable marker of the SA, a role of SP/SA in hippocampal synaptic plasticity could be firmly established using loss-of-function approaches. Further studies revealed that SP/SA participate in the regulation of Ca2+-dependent spine-specific Hebbian plasticity and in activity-dependent changes in the spine actin cytoskeleton. In this review we are summarizing recent progress made on SP/SA in Hebbian plasticity and discuss open questions such as causality, spatiotemporal dynamics and complementarity of SP/SA-dependent mechanisms. We are proposing that computational modeling of spine Ca2+-signaling and actin remodeling pathways could address some of these issues and could indicate future research directions. Moreover, reaction-diffusion simulations could help to identify key feedforward and feedback regulatory motifs regulating the switch between an LTP and an LTD signaling module in SP/SA-containing spines, thus helping to find a unified view of SP/SA action in Hebbian plasticity.
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Affiliation(s)
- Peter Jedlicka
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, D-60590 Frankfurt/Main, Germany.
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, D-60590 Frankfurt/Main, Germany.
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38
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Kim K, Saneyoshi T, Hosokawa T, Okamoto K, Hayashi Y. Interplay of enzymatic and structural functions of CaMKII in long-term potentiation. J Neurochem 2016; 139:959-972. [DOI: 10.1111/jnc.13672] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Revised: 05/09/2016] [Accepted: 05/10/2016] [Indexed: 12/17/2022]
Affiliation(s)
- Karam Kim
- Brain Science Institute; RIKEN; Wako Saitama Japan
| | | | | | - Kenichi Okamoto
- Lunenfeld-Tanenbaum Research Institute; Mount Sinai Hospital; Toronto ON Canada
- Department of Molecular Genetics; Faculty of Medicine; University of Toronto; Toronto ON Canada
| | - Yasunori Hayashi
- Brain Science Institute; RIKEN; Wako Saitama Japan
- Saitama University Brain Science Institute; Saitama University; Saitama Japan
- School of Life Science; South China Normal University; Guangzhou China
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39
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Control of Dendritic Spine Morphological and Functional Plasticity by Small GTPases. Neural Plast 2016; 2016:3025948. [PMID: 26989514 PMCID: PMC4775798 DOI: 10.1155/2016/3025948] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 01/06/2016] [Accepted: 01/19/2016] [Indexed: 11/18/2022] Open
Abstract
Structural plasticity of excitatory synapses is a vital component of neuronal development, synaptic plasticity, and behaviour. Abnormal development or regulation of excitatory synapses has also been strongly implicated in many neurodevelopmental, psychiatric, and neurodegenerative disorders. In the mammalian forebrain, the majority of excitatory synapses are located on dendritic spines, specialized dendritic protrusions that are enriched in actin. Research over recent years has begun to unravel the complexities involved in the regulation of dendritic spine structure. The small GTPase family of proteins have emerged as key regulators of structural plasticity, linking extracellular signals with the modulation of dendritic spines, which potentially underlies their ability to influence cognition. Here we review a number of studies that examine how small GTPases are activated and regulated in neurons and furthermore how they can impact actin dynamics, and thus dendritic spine morphology. Elucidating this signalling process is critical for furthering our understanding of the basic mechanisms by which information is encoded in neural circuits but may also provide insight into novel targets for the development of effective therapies to treat cognitive dysfunction seen in a range of neurological disorders.
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40
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Hu HT, Shih PY, Shih YT, Hsueh YP. The Involvement of Neuron-Specific Factors in Dendritic Spinogenesis: Molecular Regulation and Association with Neurological Disorders. Neural Plast 2015; 2016:5136286. [PMID: 26819769 PMCID: PMC4706964 DOI: 10.1155/2016/5136286] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 07/26/2015] [Indexed: 12/26/2022] Open
Abstract
Dendritic spines are the location of excitatory synapses in the mammalian nervous system and are neuron-specific subcellular structures essential for neural circuitry and function. Dendritic spine morphology is determined by the F-actin cytoskeleton. F-actin remodeling must coordinate with different stages of dendritic spinogenesis, starting from dendritic filopodia formation to the filopodia-spines transition and dendritic spine maturation and maintenance. Hundreds of genes, including F-actin cytoskeleton regulators, membrane proteins, adaptor proteins, and signaling molecules, are known to be involved in regulating synapse formation. Many of these genes are not neuron-specific, but how they specifically control dendritic spine formation in neurons is an intriguing question. Here, we summarize how ubiquitously expressed genes, including syndecan-2, NF1 (encoding neurofibromin protein), VCP, and CASK, and the neuron-specific gene CTTNBP2 coordinate with neurotransmission, transsynaptic signaling, and cytoskeleton rearrangement to control dendritic filopodia formation, filopodia-spines transition, and dendritic spine maturation and maintenance. The aforementioned genes have been associated with neurological disorders, such as autism spectrum disorders (ASDs), mental retardation, learning difficulty, and frontotemporal dementia. We also summarize the corresponding disorders in this report.
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Affiliation(s)
- Hsiao-Tang Hu
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Pu-Yun Shih
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yu-Tzu Shih
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
| | - Yi-Ping Hsueh
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan
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Kim K, Lakhanpal G, Lu HE, Khan M, Suzuki A, Hayashi MK, Narayanan R, Luyben TT, Matsuda T, Nagai T, Blanpied TA, Hayashi Y, Okamoto K. A Temporary Gating of Actin Remodeling during Synaptic Plasticity Consists of the Interplay between the Kinase and Structural Functions of CaMKII. Neuron 2015; 87:813-26. [PMID: 26291163 DOI: 10.1016/j.neuron.2015.07.023] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 06/11/2015] [Accepted: 07/17/2015] [Indexed: 12/20/2022]
Abstract
The structural modification of dendritic spines plays a critical role in synaptic plasticity. CaMKII is a pivotal molecule involved in this process through both kinase-dependent and independent structural functions, but the respective contributions of these two functions to the synaptic plasticity remain unclear. We demonstrate that the transient interplay between the kinase and structural functions of CaMKII during the induction of synaptic plasticity temporally gates the activity-dependent modification of the actin cytoskeleton. Inactive CaMKII binds F-actin, thereby limiting access of actin-regulating proteins to F-actin and stabilizing spine structure. CaMKII-activating stimuli trigger dissociation of CaMKII from F-actin through specific autophosphorylation reactions within the F-actin binding region and permits F-actin remodeling by regulatory proteins followed by reassociation and restabilization. Blocking the autophosphorylation impairs both functional and structural plasticity without affecting kinase activity. These results underpin the importance of the interplay between the kinase and structural functions of CaMKII in defining a time window permissive for synaptic plasticity.
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Affiliation(s)
- Karam Kim
- Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan
| | - Gurpreet Lakhanpal
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
| | - Hsiangmin E Lu
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Mustafa Khan
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada
| | - Akio Suzuki
- Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan
| | - Mariko Kato Hayashi
- RIKEN-MIT Neuroscience Research Center, The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Radhakrishnan Narayanan
- RIKEN-MIT Neuroscience Research Center, The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Thomas T Luyben
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada; Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Tomoki Matsuda
- The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan
| | - Takeharu Nagai
- The Institute of Scientific and Industrial Research, Osaka University, Osaka 567-0047, Japan
| | - Thomas A Blanpied
- Department of Physiology, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Program in Molecular Medicine, University of Maryland School of Medicine, Baltimore, MD 21201, USA; Program in Neuroscience, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yasunori Hayashi
- Brain Science Institute, RIKEN, Wako, Saitama 351-0198, Japan; RIKEN-MIT Neuroscience Research Center, The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Brain and Body System Science Institute, Saitama University, Saitama 338-8570, Japan; School of Life Science, South China Normal University, Guangzhou 510631, China.
| | - Kenichi Okamoto
- Lunenfeld-Tanenbaum Research Institute, Mount Sinai Hospital, Toronto, ON, M5G 1X5, Canada; RIKEN-MIT Neuroscience Research Center, The Picower Institute for Learning and Memory, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, USA; Department of Molecular Genetics, Faculty of Medicine, University of Toronto, Toronto, ON, M5S 1A8, Canada.
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Umeda T, Ramser EM, Yamashita M, Nakajima K, Mori H, Silverman MA, Tomiyama T. Intracellular amyloid β oligomers impair organelle transport and induce dendritic spine loss in primary neurons. Acta Neuropathol Commun 2015; 3:51. [PMID: 26293809 PMCID: PMC4546183 DOI: 10.1186/s40478-015-0230-2] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 08/09/2015] [Indexed: 12/15/2022] Open
Abstract
Introduction Synaptic dysfunction and intracellular transport defects are early events in Alzheimer’s disease (AD). Extracellular amyloid β (Aβ) oligomers cause spine alterations and impede the transport of proteins and organelles such as brain-derived neurotrophic factor (BDNF) and mitochondria that are required for synaptic function. Meanwhile, intraneuronal accumulation of Aβ precedes its extracellular deposition and is also associated with synaptic dysfunction in AD. However, the links between intracellular Aβ, spine alteration, and mechanisms that support synaptic maintenance such as organelle trafficking are poorly understood. Results We compared the effects of wild-type and Osaka (E693Δ)-mutant amyloid precursor proteins: the former secretes Aβ into extracellular space and the latter accumulates Aβ oligomers within cells. First we investigated the effects of intracellular Aβ oligomers on dendritic spines in primary neurons and their tau-dependency using tau knockout neurons. We found that intracellular Aβ oligomers caused a reduction in mushroom, or mature spines, independently of tau. We also found that intracellular Aβ oligomers significantly impaired the intracellular transport of BDNF, mitochondria, and recycling endosomes: cargoes essential for synaptic maintenance. A reduction in BDNF transport by intracellular Aβ oligomers was also observed in tau knockout neurons. Conclusions Our findings indicate that intracellular Aβ oligomers likely contribute to early synaptic pathology in AD and argue against the consensus that Aβ-induced spine loss and transport defects require tau.
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Kang J, Park H, Kim E. IRSp53/BAIAP2 in dendritic spine development, NMDA receptor regulation, and psychiatric disorders. Neuropharmacology 2015; 100:27-39. [PMID: 26275848 DOI: 10.1016/j.neuropharm.2015.06.019] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 06/26/2015] [Accepted: 06/28/2015] [Indexed: 01/08/2023]
Abstract
IRSp53 (also known as BAIAP2) is a multi-domain scaffolding and adaptor protein that has been implicated in the regulation of membrane and actin dynamics at subcellular structures, including filopodia and lamellipodia. Accumulating evidence indicates that IRSp53 is an abundant component of the postsynaptic density at excitatory synapses and an important regulator of actin-rich dendritic spines. In addition, IRSp53 has been implicated in diverse psychiatric disorders, including autism spectrum disorders, schizophrenia, and attention deficit/hyperactivity disorder. Mice lacking IRSp53 display enhanced NMDA (N-methyl-d-aspartate) receptor function accompanied by social and cognitive deficits, which are reversed by pharmacological suppression of NMDA receptor function. These results suggest the hypothesis that defective actin/membrane modulation in IRSp53-deficient dendritic spines may lead to social and cognitive deficits through NMDA receptor dysfunction. This article is part of the Special Issue entitled 'Synaptopathy--from Biology to Therapy'.
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Affiliation(s)
- Jaeseung Kang
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, South Korea
| | - Haram Park
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, South Korea
| | - Eunjoon Kim
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701, South Korea; Center for Synaptic Brain Dysfunctions, Institute for Basic Science (IBS), Daejeon 305-701, South Korea.
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Sgk1 regulates desmoglein 1 expression levels in oligodendrocytes in the mouse corpus callosum after chronic stress exposure. Biochem Biophys Res Commun 2015; 464:76-82. [DOI: 10.1016/j.bbrc.2015.05.109] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Accepted: 05/29/2015] [Indexed: 11/17/2022]
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Llano O, Smirnov S, Soni S, Golubtsov A, Guillemin I, Hotulainen P, Medina I, Nothwang HG, Rivera C, Ludwig A. KCC2 regulates actin dynamics in dendritic spines via interaction with β-PIX. J Cell Biol 2015; 209:671-86. [PMID: 26056138 PMCID: PMC4460141 DOI: 10.1083/jcb.201411008] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2014] [Accepted: 04/27/2015] [Indexed: 02/07/2023] Open
Abstract
Chloride extrusion in mature neurons is largely mediated by the neuron-specific potassium-chloride cotransporter KCC2. In addition, independently of its chloride transport function, KCC2 regulates the development and morphology of dendritic spines through structural interactions with the actin cytoskeleton. The mechanism of this effect remains largely unknown. In this paper, we show a novel pathway for KCC2-mediated regulation of the actin cytoskeleton in neurons. We found that KCC2, through interaction with the b isoform of Rac/Cdc42 guanine nucleotide exchange factor β-PIX, regulates the activity of Rac1 GTPase and the phosphorylation of one of the major actin-regulating proteins, cofilin-1. KCC2-deficient neurons had abnormally high levels of phosphorylated cofilin-1. Consistently, dendritic spines of these neurons exhibited a large pool of stable actin, resulting in reduced spine motility and diminished density of functional synapses. In conclusion, we describe a novel signaling pathway that couples KCC2 to the cytoskeleton and regulates the formation of glutamatergic synapses.
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Affiliation(s)
- Olaya Llano
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Sergey Smirnov
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Shetal Soni
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Andrey Golubtsov
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Isabelle Guillemin
- Neurogenetics group, Center of Excellence Hearing4All, School of Medicine and Health Sciences and Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Pirta Hotulainen
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Igor Medina
- Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale Unité 901, 13009 Marseille, France Aix-Marseille Université, Unité Mixte de Recherche 901, 13273 Marseille, France
| | - Hans Gerd Nothwang
- Neurogenetics group, Center of Excellence Hearing4All, School of Medicine and Health Sciences and Research Center for Neurosensory Sciences, Carl von Ossietzky University Oldenburg, 26111 Oldenburg, Germany
| | - Claudio Rivera
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland Institut de Neurobiologie de la Méditerranée, Institut National de la Santé et de la Recherche Médicale Unité 901, 13009 Marseille, France Aix-Marseille Université, Unité Mixte de Recherche 901, 13273 Marseille, France
| | - Anastasia Ludwig
- Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
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Hou ST, Nilchi L, Li X, Gangaraju S, Jiang SX, Aylsworth A, Monette R, Slinn J. Semaphorin3A elevates vascular permeability and contributes to cerebral ischemia-induced brain damage. Sci Rep 2015; 5:7890. [PMID: 25601765 PMCID: PMC4298747 DOI: 10.1038/srep07890] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Accepted: 12/16/2014] [Indexed: 12/25/2022] Open
Abstract
Semaphorin 3A (Sema3A) increased significantly in mouse brain following cerebral ischemia. However, the role of Sema3A in stroke brain remains unknown. Our aim was to determine wether Sema3A functions as a vascular permeability factor and contributes to ischemic brain damage. Recombinant Sema3A injected intradermally to mouse skin, or stereotactically into the cerebral cortex, caused dose- and time-dependent increases in vascular permeability, with a degree comparable to that caused by injection of a known vascular permeability factor vascular endothelial growth factor receptors (VEGF). Application of Sema3A to cultured endothelial cells caused disorganization of F-actin stress fibre bundles and increased endothelial monolayer permeability, confirming Sema3A as a permeability factor. Sema3A-mediated F-actin changes in endothelial cells were through binding to the neuropilin2/VEGFR1 receptor complex, which in turn directly activates Mical2, a F-actin modulator. Down-regulation of Mical2, using specific siRNA, alleviated Sema3A-induced F-actin disorganization, cellular morphology changes and endothelial permeability. Importantly, ablation of Sema3A expression, cerebrovascular permeability and brain damage were significantly reduced in response to transient middle cerebral artery occlusion (tMCAO) and in a mouse model of cerebral ischemia/haemorrhagic transformation. Together, these studies demonstrated that Sema3A is a key mediator of cerebrovascular permeability and contributes to brain damage caused by cerebral ischemia.
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Affiliation(s)
- Sheng Tao Hou
- 1] Department of Biology, South University of Science and Technology of China, 1088 Xueyuan Blvd, Nanshan District, Shenzhen, P.R. China, 518055 [2] Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada [3] Human Health Therapeutics Portfolio, National Research Council Canada, 1200 Montreal Road, Bldg M54, Ottawa, Ontario, K1A 0R6, Canada
| | - Ladan Nilchi
- 1] Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada [2] Human Health Therapeutics Portfolio, National Research Council Canada, 1200 Montreal Road, Bldg M54, Ottawa, Ontario, K1A 0R6, Canada
| | - Xuesheng Li
- 1] Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada [2] Human Health Therapeutics Portfolio, National Research Council Canada, 1200 Montreal Road, Bldg M54, Ottawa, Ontario, K1A 0R6, Canada
| | - Sandhya Gangaraju
- Human Health Therapeutics Portfolio, National Research Council Canada, 1200 Montreal Road, Bldg M54, Ottawa, Ontario, K1A 0R6, Canada
| | - Susan X Jiang
- Human Health Therapeutics Portfolio, National Research Council Canada, 1200 Montreal Road, Bldg M54, Ottawa, Ontario, K1A 0R6, Canada
| | - Amy Aylsworth
- Human Health Therapeutics Portfolio, National Research Council Canada, 1200 Montreal Road, Bldg M54, Ottawa, Ontario, K1A 0R6, Canada
| | - Robert Monette
- Human Health Therapeutics Portfolio, National Research Council Canada, 1200 Montreal Road, Bldg M54, Ottawa, Ontario, K1A 0R6, Canada
| | - Jacqueline Slinn
- Human Health Therapeutics Portfolio, National Research Council Canada, 1200 Montreal Road, Bldg M54, Ottawa, Ontario, K1A 0R6, Canada
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Chuang HC, Huang TN, Hsueh YP. Neuronal excitation upregulates Tbr1, a high-confidence risk gene of autism, mediating Grin2b expression in the adult brain. Front Cell Neurosci 2014; 8:280. [PMID: 25309323 PMCID: PMC4159980 DOI: 10.3389/fncel.2014.00280] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2014] [Accepted: 08/24/2014] [Indexed: 12/18/2022] Open
Abstract
The activity-regulated gene expression of transcription factors is required for neural plasticity and function in response to neuronal stimulation. T-brain-1 (TBR1), a critical neuron-specific transcription factor for forebrain development, has been recognized as a high-confidence risk gene for autism spectrum disorders. Here, we show that in addition to its role in brain development, Tbr1 responds to neuronal activation and further modulates the Grin2b expression in adult brains and mature neurons. The expression levels of Tbr1 were investigated using both immunostaining and quantitative reverse transcription polymerase chain reaction (RT-PCR) analyses. We found that the mRNA and protein expression levels of Tbr1 are induced by excitatory synaptic transmission driven by bicuculline or glutamate treatment in cultured mature neurons. The upregulation of Tbr1 expression requires the activation of both α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) and N-methyl-D-aspartate (NMDA) receptors. Furthermore, behavioral training triggers Tbr1 induction in the adult mouse brain. The elevation of Tbr1 expression is associated with Grin2b upregulation in both mature neurons and adult brains. Using Tbr1-deficient neurons, we further demonstrated that TBR1 is required for the induction of Grin2b upon neuronal activation. Taken together with the previous studies showing that TBR1 binds the Grin2b promoter and controls expression of luciferase reporter driven by Grin2b promoter, the evidence suggests that TBR1 directly controls Grin2b expression in mature neurons. We also found that the addition of the calcium/calmodulin-dependent protein kinase II (CaMKII) antagonist KN-93, but not the calcium-dependent phosphatase calcineurin antagonist cyclosporin A, to cultured mature neurons noticeably inhibited Tbr1 induction, indicating that neuronal activation upregulates Tbr1 expression in a CaMKII-dependent manner. In conclusion, our study suggests that Tbr1 plays an important role in adult mouse brains in response to neuronal activation to modulate the activity-regulated gene transcription required for neural plasticity.
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Affiliation(s)
- Hsiu-Chun Chuang
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei Taiwan ; Institute of Molecular Biology, Academia Sinica, Taipei Taiwan
| | - Tzyy-Nan Huang
- Institute of Molecular Biology, Academia Sinica, Taipei Taiwan
| | - Yi-Ping Hsueh
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei Taiwan ; Institute of Molecular Biology, Academia Sinica, Taipei Taiwan
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48
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Genetic modulation of soluble Aβ rescues cognitive and synaptic impairment in a mouse model of Alzheimer's disease. J Neurosci 2014; 34:7871-85. [PMID: 24899710 DOI: 10.1523/jneurosci.0572-14.2014] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
An unresolved debate in Alzheimer's disease (AD) is whether amyloid plaques are pathogenic, causing overt physical disruption of neural circuits, or protective, sequestering soluble forms of amyloid-β (Aβ) that initiate synaptic damage and cognitive decline. Few animal models of AD have been capable of isolating the relative contribution made by soluble and insoluble forms of Aβ to the behavioral symptoms and biochemical consequences of the disease. Here we use a controllable transgenic mouse model expressing a mutant form of amyloid precursor protein (APP) to distinguish the impact of soluble Aβ from that of deposited amyloid on cognitive function and synaptic structure. Rapid inhibition of transgenic APP modulated the production of Aβ without affecting pre-existing amyloid deposits and restored cognitive performance to the level of healthy controls in Morris water maze, radial arm water maze, and fear conditioning. Selective reduction of Aβ with a γ-secretase inhibitor provided similar improvement, suggesting that transgene suppression restored cognition, at least in part by lowering Aβ. Cognitive improvement coincided with reduced levels of synaptotoxic Aβ oligomers, greater synaptic density surrounding amyloid plaques, and increased expression of presynaptic and postsynaptic markers. Together these findings indicate that transient Aβ species underlie much of the cognitive and synaptic deficits observed in this model and demonstrate that significant functional and structural recovery can be attained without removing deposited amyloid.
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49
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Chen JR, Tseng GF, Wang YJ, Wang TJ. Exogenous dehydroisoandrosterone sulfate reverses the dendritic changes of the central neurons in aging male rats. Exp Gerontol 2014; 57:191-202. [PMID: 24929010 DOI: 10.1016/j.exger.2014.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2013] [Revised: 06/06/2014] [Accepted: 06/11/2014] [Indexed: 12/13/2022]
Abstract
Sex hormones are known to help maintaining the cognitive ability in male and female rats. Hypogonadism results in the reduction of the dendritic spines of central neurons which is believed to undermine memory and cognition and cause fatigue and poor concentration. In our previous studies, we have reported age-related regression in dendrite arbors along with loss of dendritic spines in the primary somatosensory cortical neurons in female rats. Furthermore, castration caused a reduction of dendritic spines in adult male rats. In light of this, it was surmised that dendritic structures might change in normal aging male rats with advancing age. Recently, dehydroepiandrosterone sulfate (DHEAS) has been reported to have memory-enhancing properties in aged rodents. In this study, normal aging male rats, with a reduced plasma testosterone level of 75-80%, were used to explore the changes in behavioral performance of neuronal dendritic arbor and spine density. Aging rats performed poorer in spatial learning memory (Morris water maze). Concomitantly, these rats showed regressed dendritic arbors and spine loss on the primary somatosensory cortical and hippocampal CA1 pyramidal neurons. Exogenous DHEAS and testosterone treatment reversed the behavioral deficits and partially restored the spine loss of cortical neurons in aging male rats but had no effects on the dendritic arbor shrinkage of the affected neurons. It is concluded therefore that DHEAS, has the efficacy as testosterone, and that it can exert its effects on the central neuron level to effectively ameliorate aging symptoms.
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Affiliation(s)
- Jeng-Rung Chen
- Department of Veterinary Medicine, College of Veterinary Medicine, National Chung-Hsing University, Taichung, Taiwan.
| | - Guo-Fang Tseng
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien, Taiwan
| | - Yueh-Jan Wang
- Department of Anatomy, College of Medicine, Tzu-Chi University, Hualien, Taiwan
| | - Tsyr-Jiuan Wang
- Department of Nursing, National Taichung University of Science and Technology, Taichung, Taiwan.
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50
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Hu HT, Hsueh YP. Calcium influx and postsynaptic proteins coordinate the dendritic filopodium-spine transition. Dev Neurobiol 2014; 74:1011-29. [PMID: 24753440 DOI: 10.1002/dneu.22181] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2014] [Accepted: 04/14/2014] [Indexed: 12/16/2022]
Abstract
Dendritic spines are the major locations of excitatory synapses in the mammalian central nervous system. The transformation from dendritic filopodia to dendritic spines has been recognized as one type of spinogenesis. For instance, syndecan-2 (SDC2), a synaptic heparan sulfate proteoglycan, is highly concentrated at dendritic spines and required for spinogenesis. It induces dendritic filopodia formation, followed by spine formation. However, the molecular regulation of the filopodium-spine transition induced by SDC2 is still unclear. In this report, we show that calcium is an important signal downstream of SDC2 in regulation of filopodium-spine transition but not filopodia formation. SDC2 interacted with the postsynaptic proteins calmodulin-dependent serine kinase (CASK) and LIN7 and further recruited NMDAR to the tips of filopodia induced by SDC2. Calcium influx via NMDAR promoted spine maturation because addition of EGTA or AP5 to the culture medium effectively prevented morphological change from dendritic filopodia to dendritic spines. Our data also indicated that F-actin rearrangement regulated by calcium influx is involved in the morphological change, because the knockdown of gelsolin, a calcium-activated F-actin severing molecule, impaired the filopodium-spine transition induced by SDC2. In conclusion, our study demonstrates that postsynaptic proteins coordinate to trigger calcium signalling and cytoskeleton rearrangement and consequently control filopodium-spine transition.
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Affiliation(s)
- Hsiao-Tang Hu
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, 11490, Taiwan; Institute of Molecular Biology, Academia Sinica, Taipei, 11529, Taiwan
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