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Markovinovic A, Martín-Guerrero SM, Mórotz GM, Salam S, Gomez-Suaga P, Paillusson S, Greig J, Lee Y, Mitchell JC, Noble W, Miller CCJ. Stimulating VAPB-PTPIP51 ER-mitochondria tethering corrects FTD/ALS mutant TDP43 linked Ca 2+ and synaptic defects. Acta Neuropathol Commun 2024; 12:32. [PMID: 38395965 PMCID: PMC10885568 DOI: 10.1186/s40478-024-01742-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] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 02/05/2024] [Indexed: 02/25/2024] Open
Abstract
Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are clinically linked major neurodegenerative diseases. Notably, TAR DNA-binding protein-43 (TDP43) accumulations are hallmark pathologies of FTD/ALS and mutations in the gene encoding TDP43 cause familial FTD/ALS. There are no cures for FTD/ALS. FTD/ALS display damage to a broad range of physiological functions, many of which are regulated by signaling between the endoplasmic reticulum (ER) and mitochondria. This signaling is mediated by the VAPB-PTPIP51 tethering proteins that serve to recruit regions of ER to the mitochondrial surface so as to facilitate inter-organelle communications. Several studies have now shown that disrupted ER-mitochondria signaling including breaking of the VAPB-PTPIP51 tethers are features of FTD/ALS and that for TDP43 and other familial genetic FTD/ALS insults, this involves activation of glycogen kinase-3β (GSK3β). Such findings have prompted suggestions that correcting damage to ER-mitochondria signaling and the VAPB-PTPIP51 interaction may be broadly therapeutic. Here we provide evidence to support this notion. We show that overexpression of VAPB or PTPIP51 to enhance ER-mitochondria signaling corrects mutant TDP43 induced damage to inositol 1,4,5-trisphosphate (IP3) receptor delivery of Ca2+ to mitochondria which is a primary function of the VAPB-PTPIP51 tethers, and to synaptic function. Moreover, we show that ursodeoxycholic acid (UDCA), an FDA approved drug linked to FTD/ALS and other neurodegenerative diseases therapy and whose precise therapeutic target is unclear, corrects TDP43 linked damage to the VAPB-PTPIP51 interaction. We also show that this effect involves inhibition of TDP43 mediated activation of GSK3β. Thus, correcting damage to the VAPB-PTPIP51 tethers may have therapeutic value for FTD/ALS and other age-related neurodegenerative diseases.
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Affiliation(s)
- Andrea Markovinovic
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, SE5 9RX, London, UK.
| | - Sandra M Martín-Guerrero
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, SE5 9RX, London, UK
| | - Gábor M Mórotz
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, SE5 9RX, London, UK
| | - Shaakir Salam
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, SE5 9RX, London, UK
| | - Patricia Gomez-Suaga
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, SE5 9RX, London, UK
| | - Sebastien Paillusson
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, SE5 9RX, London, UK
| | - Jenny Greig
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, SE5 9RX, London, UK
| | - Younbok Lee
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, SE5 9RX, London, UK
| | - Jacqueline C Mitchell
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, SE5 9RX, London, UK
| | - Wendy Noble
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, SE5 9RX, London, UK
| | - Christopher C J Miller
- Department of Basic and Clinical Neuroscience, Institute of Psychiatry, Psychology and Neuroscience, King's College London, SE5 9RX, London, UK.
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Wei M, Yang L, Su F, Liu Y, Zhao X, Luo L, Sun X, Liu S, Dong Z, Zhang Y, Shi YS, Liang J, Zhang C. ABHD6 drives endocytosis of AMPA receptors to regulate synaptic plasticity and learning flexibility. Prog Neurobiol 2024; 233:102559. [PMID: 38159878 DOI: 10.1016/j.pneurobio.2023.102559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Revised: 10/26/2023] [Accepted: 12/06/2023] [Indexed: 01/03/2024]
Abstract
Trafficking of α-Amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA) receptors (AMPARs), mediated by AMPAR interacting proteins, enabled neurons to maintain tuning capabilities at rest or active state. α/β-Hydrolase domain-containing 6 (ABHD6), an endocannabinoid hydrolase, was an AMPAR auxiliary subunit found to negatively regulate the surface delivery of AMPARs. While ABHD6 was found to prevent AMPAR tetramerization in endoplasmic reticulum, ABHD6 was also reported to localize at postsynaptic site. Yet, the role of ABHD6 interacting with AMPAR at postsynaptic site, and the physiological significance of ABHD6 regulating AMPAR trafficking remains elusive. Here, we generated the ABHD6 knockout (ABHD6KO) mice and found that deletion of ABHD6 selectively enhanced AMPAR-mediated basal synaptic responses and the surface expression of postsynaptic AMPARs. Furthermore, we found that loss of ABHD6 impaired hippocampal long-term depression (LTD) and synaptic downscaling in hippocampal synapses. AMPAR internalization assays revealed that ABHD6 was essential for neuronal activity-dependent endocytosis of surface AMPARs, which is independent of ABHD6's hydrolase activity. The defects of AMPAR endocytosis and LTD are expressed as deficits in learning flexibility in ABHD6KO mice. Collectively, we demonstrated that ABHD6 is an endocytic accessory protein promoting AMPAR endocytosis, thereby contributes to the formation of LTD, synaptic downscaling and reversal learning.
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Affiliation(s)
- Mengping Wei
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China.
| | - Lei Yang
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Feng Su
- Peking-Tsinghua Center for Life Sciences, Academy for Advanced Interdisciplinary Studies, Peking University, Beijing 100871, China
| | - Ying Liu
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing 100101, China
| | - Xinyi Zhao
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Lin Luo
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Xinyue Sun
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Sen Liu
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China
| | - Zhaoqi Dong
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China
| | - Yong Zhang
- Department of Neurobiology, School of Basic Medical Sciences and Neuroscience Research Institute, Key Lab for Neuroscience, Ministry of Education of China and National Health Commission of the PR China, IDG/McGovern Institute for Brain Research at PKU, Peking University, Beijing 100083, China
| | - Yun Stone Shi
- Ministry of Education Key Laboratory of Model Animal for Disease Study, Model Animal Research Center, Medical School, Nanjing University, Nanjing 210032, China
| | - Jing Liang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China; Department of Psychology, University of Chinese Academy of Sciences, Beijing 100101, China.
| | - Chen Zhang
- School of Basic Medical Sciences, Beijing Key Laboratory of Neural Regeneration and Repair, Advanced Innovation Center for Human Brain Protection, Capital Medical University, Beijing 100069, China; State Key Laboratory of Neurology and Oncology Drug Development, Nanjing 210000, Jiangsu, China; Chinese Institute for Brain Research, Beijing 102206, China.
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Malasala S, Azimian F, Chen YH, Twiss JL, Boykin C, Akhtar SN, Lu Q. Enabling Systemic Identification and Functionality Profiling for Cdc42 Homeostatic Modulators. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.05.574351. [PMID: 38260445 PMCID: PMC10802479 DOI: 10.1101/2024.01.05.574351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2024]
Abstract
Homeostatic modulation is pivotal in modern therapeutics. However, the discovery of bioactive materials to achieve this functionality is often random and unpredictive. Here, we enabled a systemic identification and functional classification of chemicals that elicit homeostatic modulation of signaling through Cdc42, a classical small GTPase of Ras superfamily. Rationally designed for high throughput screening, the capture of homeostatic modulators (HMs) along with molecular re-docking uncovered at least five functionally distinct classes of small molecules. This enabling led to partial agonists, hormetic agonists, bona fide activators and inhibitors, and ligand-enhanced agonists. Novel HMs exerted striking functionality in bradykinin-Cdc42 activation of actin remodelingand modified Alzheimer's disease-like behavior in mouse model. This concurrent computer-aided and experimentally empowered HM profiling highlights a model path for predicting HM landscape. One Sentence Summary With concurrent experimental biochemical profiling and in silico computer-aided drug discovery (CADD) analysis, this study enabled a systemic identification and holistic classification of Cdc42 homeostatic modulators (HMs) and demonstrated the power of CADD to predict HM classes that can mimic the pharmacological functionality of interests. Introduction Maintainingbody homeostasisis the ultimate keyto health. Thereare rich resources of bioactive materials for this functionality from both natural and synthetic chemical repertories including partial agonists (PAs) and various allosteric modulators. These homeostatic modulators (HMs) play a unique role in modern therapeutics for human diseases such as mental disorders and drug addiction. Buspirone, for example, acts as a PA for serotonin 5-HT 1A receptor but is an antagonist of the dopamine D 2 receptor. Such medical useto treat general anxietydisorders (GADs) has become one of the most-commonly prescribed medications. However, most HMs in current uses target membrane proteins and are often derived from random discoveries. HMs as therapeutics targeting cytoplasmic proteins are even more rare despite that they are in paramount needs (e. g. targeting Ras superfamily small GTPases). Rationale Cdc42, a classical member of small GTPases of Ras superfamily, regulates PI3K-AKT and Raf-MEK-ERK pathways and has been implicated in various neuropsychiatric and mental disorders as well as addictive diseases and cancer. We previously reported the high-throughput in-silico screening followed by biological characterization of novel small molecule modulators (SMMs) of Cdc42-intersectin (ITSN) protein-protein interactions (PPIs). Based on a serendipitously discovered SMM ZCL278 with PA profile as a model compound, we hypothesized that there are more varieties of such HMs of Cdc42 signaling, and the model HMs can be defined by their distinct Cdc42-ITSN binding mechanisms using computer-aided drug discovery (CADD) analysis. We further reasoned that molecular modeling coupled with experimental profiling can predict HM spectrum and thus open the door for the holistic identification and classification of multifunctional cytoplasmic target-dependent HMs as therapeutics. Results The originally discovered Cdc42 inhibitor ZCL278 displaying PA properties prompted the inquiry whether this finding represented a random encounter of PAs or whether biologically significant PAs can be widely present. The top ranked compounds were initially defined by structural fitness and binding scores to Cdc42. Because higher binding scores do not necessarily translate to higher functionality, we performed exhaustive experimentations with over 2,500 independent Cdc42-GEF (guanine nucleotide exchange factor) assays to profile the GTP loading activities on all 44 top ranked compounds derived from the SMM library. The N-MAR-GTP fluorophore-based Cdc42-GEF assay platform provided the first glimpse of the breadth of HMs. A spectrum of Cdc42 HMs was uncovered that can be categorized into five functionally distinct classes: Class I-partial competitive agonists, Class II-hormetic agonists, Class III- bona fide inhibitors (or inverse agonists), Class IV- bona fide activators or agonists, and Class V-ligand-enhanced agonists. Remarkably, model HMs such as ZCL278, ZCL279, and ZCL367 elicited striking biological functionality in bradykinin-Cdc42 activation of actin remodeling and modified Alzheimer's disease (AD)-like behavior in mouse model. Concurrently, we applied Schrödinger-enabled analyses to perform CADD predicted classification of Cdc42 HMs. We modified the classic molecular docking to instill a preferential binding pocket order (PBPO) of Cdc42-ITSN, which was based on the five binding pockets in interface of Cdc42-ITSN. We additionally applied a structure-based pharmacophore hypothesis generation for the model compounds. Then, using Schrödinger's Phase Shape, 3D ligand alignments assigned HMs to Class I, II, III, IV, and V compounds. In this HM library compounds, PBPO, matching pharmacophoric featuring, and shape alignment, all put ZCL993 in Class II compound category, which was confirmed in the Cdc42-GEF assay. Conclusion HMs can target diseased cells or tissues while minimizing impacts on tissues that are unaffected. Using Cdc42 HM model compounds as a steppingstone, GTPase activation-based screening of SMM library uncovered five functionally distinct Cdc42 HM classes among which novel efficacies towards alleviating dysregulated AD-like features in mice were identified. Furthermore, molecular re-docking of HM model compounds led to the concept of PBPO. The CADD analysis with PBPO revealed similar profile in a color-coded spectrum to these five distinct classes of Cdc42 HMs identified by biochemical functionality-based screening. The current study enabled a systemic identification and holistic classification of Cdc42 HMs and demonstrated the power of CADD to predict an HM category that can mimic the pharmacological functionality of interests. With artificial intelligence/machine learning (AI/ML) on the horizon to mirror experimental pharmacological discovery like AlphaFold for protein structure prediction, our study highlights a model path to actively capture and profile HMs in potentially any PPI landscape. Graphic Abstract Identification and functional classification of Cdc42 homeostatic modulators HMs Using Cdc42 HM model compounds as reference, GTPase activation-based screening of compound libraries uncovered five functionally distinct Cdc42 HM classes. HMs showed novel efficacies towards alleviating dysregulated Alzheimer's disease (AD)-like behavioral and molecular deficits. In parallel, molecular re-docking of HM model compounds established their preferential binding pocket orders (PBPO). PBPO-based profiling (Red reflects the most, whereas green reflects the least, preferable binding pocket) revealed trends of similar pattern to the five classes from the functionality-based classification.
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Bingham D, Jakobs CE, Wernert F, Boroni-Rueda F, Jullien N, Schentarra EM, Friedl K, Da Costa Moura J, van Bommel DM, Caillol G, Ogawa Y, Papandréou MJ, Leterrier C. Presynapses contain distinct actin nanostructures. J Cell Biol 2023; 222:e202208110. [PMID: 37578754 PMCID: PMC10424573 DOI: 10.1083/jcb.202208110] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 06/07/2023] [Accepted: 07/25/2023] [Indexed: 08/15/2023] Open
Abstract
The architecture of the actin cytoskeleton that concentrates at presynapses remains poorly known, hindering our understanding of its roles in synaptic physiology. In this work, we measure and visualize presynaptic actin by diffraction-limited and super-resolution microscopy, thanks to a validated model of bead-induced presynapses in cultured neurons. We identify a major population of actin-enriched presynapses that concentrates more presynaptic components and shows higher synaptic vesicle cycling than their non-enriched counterparts. Pharmacological perturbations point to an optimal actin amount and the presence of distinct actin structures within presynapses. We directly visualize these nanostructures using Single Molecule Localization Microscopy (SMLM), defining three distinct types: an actin mesh at the active zone, actin rails between the active zone and deeper reserve pools, and actin corrals around the whole presynaptic compartment. Finally, CRISPR-tagging of endogenous actin allows us to validate our results in natural synapses between cultured neurons, confirming the role of actin enrichment and the presence of three types of presynaptic actin nanostructures.
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Affiliation(s)
- Dominic Bingham
- CNRS, INP UMR7051, NeuroCyto, Aix Marseille Université, Marseille, France
| | | | - Florian Wernert
- CNRS, INP UMR7051, NeuroCyto, Aix Marseille Université, Marseille, France
| | - Fanny Boroni-Rueda
- CNRS, INP UMR7051, NeuroCyto, Aix Marseille Université, Marseille, France
| | - Nicolas Jullien
- CNRS, INP UMR7051, NeuroCyto, Aix Marseille Université, Marseille, France
| | | | - Karoline Friedl
- CNRS, INP UMR7051, NeuroCyto, Aix Marseille Université, Marseille, France
- Abbelight, Cachan, France
| | | | | | - Ghislaine Caillol
- CNRS, INP UMR7051, NeuroCyto, Aix Marseille Université, Marseille, France
| | - Yuki Ogawa
- Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA
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Salmonella effector SopB reorganizes cytoskeletal vimentin to maintain replication vacuoles for efficient infection. Nat Commun 2023; 14:478. [PMID: 36717589 PMCID: PMC9885066 DOI: 10.1038/s41467-023-36123-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 01/16/2023] [Indexed: 01/31/2023] Open
Abstract
A variety of intracellular bacteria modulate the host cytoskeleton to establish subcellular niches for replication. However, the role of intermediate filaments, which are crucial for mechanical strength and resilience of the cell, and in bacterial vacuole preservation remains unclear. Here, we show that Salmonella effector SopB reorganizes the vimentin network to form cage-like structures that surround Salmonella-containing vacuoles (SCVs). Genetic removal of vimentin markedly disrupts SCV organization, significantly reduces bacterial replication and cell death. Mechanistically, SopB uses its N-terminal Cdc42-binding domain to interact with and activate Cdc42 GTPase, which in turn recruits vimentin around SCVs. A high-content imaging-based screening identified that MEK1/2 inhibition led to vimentin dispersion. Our work therefore elucidates the signaling axis SopB-Cdc42-MEK1/2 as mobilizing host vimentin to maintain concrete SCVs and identifies a mechanism contributing to Salmonella replication. Importantly, Trametinib, a clinically-approved MEK1/2 inhibitor identified in the screen, displayed significant anti-infection efficacy against Salmonella both in vitro and in vivo, and may provide a therapeutic option for treating drug-tolerant salmonellosis.
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Bonansco C, Cerpa W, Inestrosa NC. How Are Synapses Born? A Functional and Molecular View of the Role of the Wnt Signaling Pathway. Int J Mol Sci 2022; 24:ijms24010708. [PMID: 36614149 PMCID: PMC9821221 DOI: 10.3390/ijms24010708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 12/16/2022] [Accepted: 12/18/2022] [Indexed: 01/03/2023] Open
Abstract
Synaptic transmission is a dynamic process that requires precise regulation. Early in life, we must be able to forge appropriate connections (add and remove) to control our behavior. Neurons must recognize appropriate targets, and external soluble factors that activate specific signaling cascades provide the regulation needed to achieve this goal. Wnt signaling has been implicated in several forms of synaptic plasticity, including functional and structural changes associated with brain development. The analysis of synapses from an electrophysiological perspective allows us to characterize the functional role of cellular signaling pathways involved in brain development. The application of quantal theory to principles of developmental plasticity offers the possibility of dissecting the function of structural changes associated with the birth of new synapses as well as the maturation of immature silent synapses. Here, we focus on electrophysiological and molecular evidence that the Wnt signaling pathway regulates glutamatergic synaptic transmission, specifically N-methyl-d-aspartate receptors (NMDARs), to control the birth of new synapses. We also focus on the role of Wnts in the conversion of silent synapses into functional synapses.
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Affiliation(s)
- Christian Bonansco
- Centro de Neurobiología y Fisiopatología Integrativa (CENFI), Instituto de Fisiología, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile
- Correspondence: (C.B.); (N.C.I.)
| | - Waldo Cerpa
- Laboratorio de Función y Patología Neuronal, Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
- Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas 6200000, Chile
| | - Nibaldo C. Inestrosa
- Centro de Excelencia en Biomedicina de Magallanes (CEBIMA), Universidad de Magallanes, Punta Arenas 6200000, Chile
- Centro de Envejecimiento y Regeneración (CARE UC), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
- Correspondence: (C.B.); (N.C.I.)
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Hasegawa K, Matsui TK, Kondo J, Kuwako KI. N-WASP-Arp2/3 signaling controls multiple steps of dendrite maturation in Purkinje cells in vivo. Development 2022; 149:285127. [PMID: 36469048 DOI: 10.1242/dev.201214] [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: 08/24/2022] [Accepted: 11/01/2022] [Indexed: 12/12/2022]
Abstract
During neural development, the actin filament network must be precisely regulated to form elaborate neurite structures. N-WASP tightly controls actin polymerization dynamics by activating an actin nucleator Arp2/3. However, the importance of N-WASP-Arp2/3 signaling in the assembly of neurite architecture in vivo has not been clarified. Here, we demonstrate that N-WASP-Arp2/3 signaling plays a crucial role in the maturation of cerebellar Purkinje cell (PC) dendrites in vivo in mice. N-WASP was expressed and activated in developing PCs. Inhibition of Arp2/3 and N-WASP from the beginning of dendrite formation severely disrupted the establishment of a single stem dendrite, which is a characteristic basic structure of PC dendrites. Inhibition of Arp2/3 after stem dendrite formation resulted in hypoplasia of the PC dendritic tree. Cdc42, an upstream activator of N-WASP, is required for N-WASP-Arp2/3 signaling-mediated PC dendrite maturation. In addition, overactivation of N-WASP is also detrimental to dendrite formation in PCs. These findings reveal that proper activation of N-WASP-Arp2/3 signaling is crucial for multiple steps of PC dendrite maturation in vivo.
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Affiliation(s)
- Koichi Hasegawa
- Department of Neural and Muscular Physiology, School of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane 693-8501, Japan
| | - Takeshi K Matsui
- Department of Neural and Muscular Physiology, School of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane 693-8501, Japan
| | - Junpei Kondo
- Department of Neural and Muscular Physiology, School of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane 693-8501, Japan
| | - Ken-Ichiro Kuwako
- Department of Neural and Muscular Physiology, School of Medicine, Shimane University, 89-1 Enya-cho, Izumo-shi, Shimane 693-8501, Japan
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O'Neil SD, Rácz B, Brown WE, Gao Y, Soderblom EJ, Yasuda R, Soderling SH. Action potential-coupled Rho GTPase signaling drives presynaptic plasticity. eLife 2021; 10:63756. [PMID: 34269176 PMCID: PMC8285108 DOI: 10.7554/elife.63756] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Accepted: 07/06/2021] [Indexed: 12/30/2022] Open
Abstract
In contrast to their postsynaptic counterparts, the contributions of activity-dependent cytoskeletal signaling to presynaptic plasticity remain controversial and poorly understood. To identify and evaluate these signaling pathways, we conducted a proteomic analysis of the presynaptic cytomatrix using in vivo biotin identification (iBioID). The resultant proteome was heavily enriched for actin cytoskeleton regulators, including Rac1, a Rho GTPase that activates the Arp2/3 complex to nucleate branched actin filaments. Strikingly, we find Rac1 and Arp2/3 are closely associated with synaptic vesicle membranes in adult mice. Using three independent approaches to alter presynaptic Rac1 activity (genetic knockout, spatially restricted inhibition, and temporal optogenetic manipulation), we discover that this pathway negatively regulates synaptic vesicle replenishment at both excitatory and inhibitory synapses, bidirectionally sculpting short-term synaptic depression. Finally, we use two-photon fluorescence lifetime imaging to show that presynaptic Rac1 activation is coupled to action potentials by voltage-gated calcium influx. Thus, this study uncovers a previously unrecognized mechanism of actin-regulated short-term presynaptic plasticity that is conserved across excitatory and inhibitory terminals. It also provides a new proteomic framework for better understanding presynaptic physiology, along with a blueprint of experimental strategies to isolate the presynaptic effects of ubiquitously expressed proteins.
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Affiliation(s)
| | - Bence Rácz
- Department of Anatomy and Histology, University of Veterinary Medicine, Budapest, Hungary
| | - Walter Evan Brown
- Department of Cell Biology, Duke University Medical Center, Durham, United States
| | - Yudong Gao
- Department of Cell Biology, Duke University Medical Center, Durham, United States
| | - Erik J Soderblom
- Department of Cell Biology, Duke University Medical Center, Durham, United States.,Proteomics and Metabolomics Shared Resource and Center for Genomic and Computational Biology, Duke University Medical Center, Durham, United States
| | - Ryohei Yasuda
- Max Planck Florida Institute for Neuroscience, Jupiter, United States
| | - Scott H Soderling
- Department of Neurobiology, Duke University Medical Center, Durham, United States.,Department of Cell Biology, Duke University Medical Center, Durham, United States
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Proteomic Analysis Unveils Expressional Changes in Cytoskeleton- and Synaptic Plasticity-Associated Proteins in Rat Brain Six Months after Withdrawal from Morphine. Life (Basel) 2021; 11:life11070683. [PMID: 34357055 PMCID: PMC8304287 DOI: 10.3390/life11070683] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 06/28/2021] [Accepted: 07/10/2021] [Indexed: 11/17/2022] Open
Abstract
Drug withdrawal is associated with abstinence symptoms including deficits in cognitive functions that may persist even after prolonged discontinuation of drug intake. Cognitive deficits are, at least partially, caused by alterations in synaptic plasticity but the precise molecular mechanisms have not yet been fully identified. In the present study, changes in proteomic and phosphoproteomic profiles of selected brain regions (cortex, hippocampus, striatum, and cerebellum) from rats abstaining for six months after cessation of chronic treatment with morphine were determined by label-free quantitative (LFQ) proteomic analysis. Interestingly, prolonged morphine withdrawal was found to be associated especially with alterations in protein phosphorylation and to a lesser extent in protein expression. Gene ontology (GO) term analysis revealed enrichment in biological processes related to synaptic plasticity, cytoskeleton organization, and GTPase activity. More specifically, significant changes were observed in proteins localized in synaptic vesicles (e.g., synapsin-1, SV2a, Rab3a), in the active zone of the presynaptic nerve terminal (e.g., Bassoon, Piccolo, Rims1), and in the postsynaptic density (e.g., cadherin 13, catenins, Arhgap35, Shank3, Arhgef7). Other differentially phosphorylated proteins were associated with microtubule dynamics (microtubule-associated proteins, Tppp, collapsin response mediator proteins) and the actin–spectrin network (e.g., spectrins, adducins, band 4.1-like protein 1). Taken together, a six-month morphine withdrawal was manifested by significant alterations in the phosphorylation of synaptic proteins. The altered phosphorylation patterns modulating the function of synaptic proteins may contribute to long-term neuroadaptations induced by drug use and withdrawal.
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Guiler W, Koehler A, Boykin C, Lu Q. Pharmacological Modulators of Small GTPases of Rho Family in Neurodegenerative Diseases. Front Cell Neurosci 2021; 15:661612. [PMID: 34054432 PMCID: PMC8149604 DOI: 10.3389/fncel.2021.661612] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Accepted: 04/08/2021] [Indexed: 12/22/2022] Open
Abstract
Classical Rho GTPases, including RhoA, Rac1, and Cdc42, are members of the Ras small GTPase superfamily and play essential roles in a variety of cellular functions. Rho GTPase signaling can be turned on and off by specific GEFs and GAPs, respectively. These features empower Rho GTPases and their upstream and downstream modulators as targets for scientific research and therapeutic intervention. Specifically, significant therapeutic potential exists for targeting Rho GTPases in neurodegenerative diseases due to their widespread cellular activity and alterations in neural tissues. This study will explore the roles of Rho GTPases in neurodegenerative diseases with focus on the applications of pharmacological modulators in recent discoveries. There have been exciting developments of small molecules, nonsteroidal anti-inflammatory drugs (NSAIDs), and natural products and toxins for each classical Rho GTPase category. A brief overview of each category followed by examples in their applications will be provided. The literature on their roles in various diseases [e.g., Alzheimer's disease (AD), Parkinson's disease (PD), Amyotrophic lateral sclerosis (ALS), Frontotemporal dementia (FTD), and Multiple sclerosis (MS)] highlights the unique and broad implications targeting Rho GTPases for potential therapeutic intervention. Clearly, there is increasing knowledge of therapeutic promise from the discovery of pharmacological modulators of Rho GTPases for managing and treating these conditions. The progress is also accompanied by the recognition of complex Rho GTPase modulation where targeting its signaling can improve some aspects of pathogenesis while exacerbating others in the same disease model. Future directions should emphasize the importance of elucidating how different Rho GTPases work in concert and how they produce such widespread yet different cellular responses during neurodegenerative disease progression.
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Affiliation(s)
| | | | | | - Qun Lu
- Department of Anatomy and Cell Biology, The Harriet and John Wooten Laboratory for Alzheimer’s and Neurogenerative Diseases Research, Brody School of Medicine, East Carolina University, Greenville, NC, United States
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MMP-9 Signaling Pathways That Engage Rho GTPases in Brain Plasticity. Cells 2021; 10:cells10010166. [PMID: 33467671 PMCID: PMC7830260 DOI: 10.3390/cells10010166] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 01/12/2021] [Accepted: 01/12/2021] [Indexed: 02/08/2023] Open
Abstract
The extracellular matrix (ECM) has been identified as a critical factor affecting synaptic function. It forms a functional scaffold that provides both the structural support and the reservoir of signaling molecules necessary for communication between cellular constituents of the central nervous system (CNS). Among numerous ECM components and modifiers that play a role in the physiological and pathological synaptic plasticity, matrix metalloproteinase 9 (MMP-9) has recently emerged as a key molecule. MMP-9 may contribute to the dynamic remodeling of structural and functional plasticity by cleaving ECM components and cell adhesion molecules. Notably, MMP-9 signaling was shown to be indispensable for long-term memory formation that requires synaptic remodeling. The core regulators of the dynamic reorganization of the actin cytoskeleton and cell adhesion are the Rho family of GTPases. These proteins have been implicated in the control of a wide range of cellular processes occurring in brain physiology and pathology. Here, we discuss the contribution of Rho GTPases to MMP-9-dependent signaling pathways in the brain. We also describe how the regulation of Rho GTPases by post-translational modifications (PTMs) can influence these processes.
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Luo H, Wu PF, Cao Y, Jin M, Shen TT, Wang J, Huang JG, Han QQ, He JG, Deng SL, Ni L, Hu ZL, Long LH, Wang F, Chen JG. Angiotensin-Converting Enzyme Inhibitor Rapidly Ameliorates Depressive-Type Behaviors via Bradykinin-Dependent Activation of Mammalian Target of Rapamycin Complex 1. Biol Psychiatry 2020; 88:415-425. [PMID: 32220499 DOI: 10.1016/j.biopsych.2020.02.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2019] [Revised: 01/22/2020] [Accepted: 02/03/2020] [Indexed: 12/21/2022]
Abstract
BACKGROUND Angiotensin-converting enzyme inhibitors (ACEIs) are widely prescribed antihypertensive agents. Intriguingly, case reports and clinical trials have indicated that ACEIs, including captopril and lisinopril, may have a rapid mood-elevating effect in certain patients, but few experimental studies have investigated their value as fast-onset antidepressants. METHODS The present study consisted of a series of experiments using biochemical assays, immunohistochemistry, and behavioral techniques to examine the effect and mechanism of captopril on depressive-like behavior in 2 animal models, the chronic unpredictable stress model and the chronic social defeat stress model. RESULTS Captopril (19.5 or 39 mg/kg, intraperitoneal injection) exerted rapid antidepressant activity in mice treated under the chronic unpredictable stress model and mice treated under the chronic social defeat stress model. Pharmacokinetic analysis revealed that captopril crossed the blood-brain barrier and that lisinopril, another ACEI with better blood-brain barrier permeability, exerted a faster and longer-lasting effect at a same molar equivalent dose. This antidepressant effect seemed to be independent of the renin-angiotensin system, but dependent on the bradykinin (BK) system, since the decreased BK detected in the stressed mice could be reversed by captopril. The hypofunction of the downstream effector of BK, Cdc42 (cell division control protein 42) homolog, contributed to the stress-induced loss of dendritic spines, which was rapidly reversed by captopril via activating the mTORC1 (mammalian target of rapamycin complex 1) pathway. CONCLUSIONS Our findings indicate that the BK-dependent activation of mTORC1 may represent a promising mechanism underlying antidepressant pharmacology. Considering their affordability and availability, ACEIs may emerge as a novel fast-onset antidepressant, especially for patients with comorbid depression and hypertension.
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Affiliation(s)
- Han Luo
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Peng-Fei Wu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, Hubei, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Yu Cao
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ming Jin
- Department of Pharmaceutics, College of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Tian-Tian Shen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Ji Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jian-Geng Huang
- Department of Pharmaceutics, College of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Qian-Qian Han
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jin-Gang He
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Si-Long Deng
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Lan Ni
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Zhuang-Li Hu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, Hubei, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China
| | - Li-Hong Long
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, Hubei, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Fang Wang
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, Hubei, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, Hubei, China; The Collaborative-Innovation Center for Brain Science, Wuhan, Hubei, China.
| | - Jian-Guo Chen
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China; Key Laboratory of Neurological Diseases (HUST), Ministry of Education of China, Wuhan, Hubei, China; The Key Laboratory for Drug Target Researches and Pharmacodynamic Evaluation of Hubei Province, Wuhan, Hubei, China; Laboratory of Neuropsychiatric Diseases, The Institute of Brain Research, Huazhong University of Science and Technology, Wuhan, Hubei, China; The Collaborative-Innovation Center for Brain Science, Wuhan, Hubei, China.
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Li X, Qin L, Li Y, Yu H, Zhang Z, Tao C, Liu Y, Xue Y, Zhang X, Xu Z, Wang Y, Lou H, Tan Z, Saftig P, Chen Z, Xu T, Bi G, Duan S, Gao Z. Presynaptic Endosomal Cathepsin D Regulates the Biogenesis of GABAergic Synaptic Vesicles. Cell Rep 2019; 28:1015-1028.e5. [DOI: 10.1016/j.celrep.2019.06.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Revised: 03/16/2019] [Accepted: 05/31/2019] [Indexed: 12/18/2022] Open
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Qu L, Pan C, He SM, Lang B, Gao GD, Wang XL, Wang Y. The Ras Superfamily of Small GTPases in Non-neoplastic Cerebral Diseases. Front Mol Neurosci 2019; 12:121. [PMID: 31213978 PMCID: PMC6555388 DOI: 10.3389/fnmol.2019.00121] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Accepted: 04/25/2019] [Indexed: 12/22/2022] Open
Abstract
The small GTPases from the Ras superfamily play crucial roles in basic cellular processes during practically the entire process of neurodevelopment, including neurogenesis, differentiation, gene expression, membrane and protein traffic, vesicular trafficking, and synaptic plasticity. Small GTPases are key signal transducing enzymes that link extracellular cues to the neuronal responses required for the construction of neuronal networks, as well as for synaptic function and plasticity. Different subfamilies of small GTPases have been linked to a number of non-neoplastic cerebral diseases such as Alzheimer’s disease (AD), Parkinson’s disease (PD), intellectual disability, epilepsy, drug addiction, Huntington’s disease (HD), amyotrophic lateral sclerosis (ALS) and a large number of idiopathic cerebral diseases. Here, we attempted to make a clearer illustration of the relationship between Ras superfamily GTPases and non-neoplastic cerebral diseases, as well as their roles in the neural system. In future studies, potential treatments for non-neoplastic cerebral diseases which are based on small GTPase related signaling pathways should be explored further. In this paper, we review all the available literature in support of this possibility.
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Affiliation(s)
- Liang Qu
- Department of Neurosurgery, Tangdu Hospital, Air Force Military Medical University, Xi'an, China
| | - Chao Pan
- Beijing Institute of Biotechnology, Beijing, China
| | - Shi-Ming He
- Department of Neurosurgery, Tangdu Hospital, Air Force Military Medical University, Xi'an, China.,Department of Neurosurgery, Xi'an International Medical Center, Xi'an, China
| | - Bing Lang
- The School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom.,Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, China
| | - Guo-Dong Gao
- Department of Neurosurgery, Tangdu Hospital, Air Force Military Medical University, Xi'an, China
| | - Xue-Lian Wang
- Department of Neurosurgery, Tangdu Hospital, Air Force Military Medical University, Xi'an, China
| | - Yuan Wang
- Department of Neurosurgery, Tangdu Hospital, Air Force Military Medical University, Xi'an, China
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15
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Piniella D, Martínez-Blanco E, Ibáñez I, Bartolomé-Martín D, Porlan E, Díez-Guerra J, Giménez C, Zafra F. Identification of novel regulatory partners of the glutamate transporter GLT-1. Glia 2018; 66:2737-2755. [PMID: 30394597 DOI: 10.1002/glia.23524] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 07/27/2018] [Accepted: 07/30/2018] [Indexed: 01/23/2023]
Abstract
We used proximity-dependent biotin identification (BioID) to find proteins that potentially interact with the major glial glutamate transporter, GLT-1, and we studied how these interactions might affect its activity. GTPase Rac1 was one protein identified, and interfering with its GTP/GDP cycle in mixed primary rat brain cultures affected both the clustering of GLT-1 at the astrocytic processes and the transport kinetics, increasing its uptake activity at low micromolar glutamate concentrations in a manner that was dependent on the effector kinase PAK1 and the actin cytoskeleton. Interestingly, the same manipulations had a different effect on another glial glutamate transporter, GLAST, inhibiting its activity. Importantly, glutamate acts through metabotropic receptors to stimulate the activity of Rac1 in astrocytes, supporting the existence of cross-talk between extracellular glutamate and the astrocytic form of the GLT-1 regulated by Rac1. CDC42EP4/BORG4 (a CDC42 effector) was also identified in the BioID screen, and it is a protein that regulates the assembly of septins and actin fibers, influencing the organization of the cytoskeleton. We found that GLT-1 interacts with septins, which reduces its lateral mobility at the cell surface. Finally, the G-protein subunit GNB4 dampens the activity of GLT-1, as revealed by its response to the activator peptide mSIRK, both in heterologous systems and in primary brain cultures. This effect occurs rapidly and thus, it is unlikely to depend on cytoskeletal dynamics. These novel interactions shed new light on the events controlling GLT-1 activity, thereby helping us to better understand how glutamate homeostasis is maintained in the brain.
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Affiliation(s)
- Dolores Piniella
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain.,IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
| | - Elena Martínez-Blanco
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain.,IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
| | - Ignacio Ibáñez
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain.,IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
| | - David Bartolomé-Martín
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain.,IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
| | - Eva Porlan
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain.,IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
| | - Javier Díez-Guerra
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain
| | - Cecilio Giménez
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain.,IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
| | - Francisco Zafra
- Centro de Biología Molecular Severo Ochoa, Facultad de Ciencias, Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid, Madrid, Spain.,IdiPAZ, Instituto de Salud Carlos III, Madrid, Spain
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Fang C, Wu B, Le NTT, Imberdis T, Mercer RCC, Harris DA. Prions activate a p38 MAPK synaptotoxic signaling pathway. PLoS Pathog 2018; 14:e1007283. [PMID: 30235355 PMCID: PMC6147624 DOI: 10.1371/journal.ppat.1007283] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 08/15/2018] [Indexed: 11/19/2022] Open
Abstract
Synaptic degeneration is one of the earliest pathological correlates of prion disease, and it is a major determinant of the progression of clinical symptoms. However, the cellular and molecular mechanisms underlying prion synaptotoxicity are poorly understood. Previously, we described an experimental system in which treatment of cultured hippocampal neurons with purified PrPSc, the infectious form of the prion protein, induces rapid retraction of dendritic spines, an effect that is entirely dependent on expression of endogenous PrPC by the target neurons. Here, we use this system to dissect pharmacologically the underlying cellular and molecular mechanisms. We show that PrPSc initiates a stepwise synaptotoxic signaling cascade that includes activation of NMDA receptors, calcium influx, stimulation of p38 MAPK and several downstream kinases, and collapse of the actin cytoskeleton within dendritic spines. Synaptic degeneration is restricted to excitatory synapses, spares presynaptic structures, and results in decrements in functional synaptic transmission. Pharmacological inhibition of any one of the steps in the signaling cascade, as well as expression of a dominant-negative form of p38 MAPK, block PrPSc-induced spine degeneration. Moreover, p38 MAPK inhibitors actually reverse the degenerative process after it has already begun. We also show that, while PrPC mediates the synaptotoxic effects of both PrPSc and the Alzheimer’s Aβ peptide in this system, the two species activate distinct signaling pathways. Taken together, our results provide powerful insights into the biology of prion neurotoxicity, they identify new, druggable therapeutic targets, and they allow comparison of prion synaptotoxic pathways with those involved in other neurodegenerative diseases. Prion diseases are a group of fatal neurodegenerative disorders that includes Creutzfeldt-Jakob disease and kuru in humans, and bovine spongiform encephalopathy in cattle. The infectious agent, or prion, that transmits these diseases is a naked protein molecule, the prion protein (PrP), which is an altered form of a normal, cellular protein. Although a great deal is known about how prions propagate themselves and transmit infection, the process by which they actually cause neurons to degenerate has remained mysterious. Here, we have used a specialized neuronal culture system to dissect the cellular and molecular mechanisms by which prions damage synapses, the structures that connect nerve cells and that play a crucial role in learning, memory, and neurological disease. Our results define a stepwise molecular pathway underlying prion synaptic toxicity, which involves activation of glutamate neurotransmitter receptors, influx of calcium ions into the neuron, and stimulation of specific mitogen-activated protein kinases, which attach phosphate groups to proteins to regulate their activity. We demonstrate that specific drugs, as well as a dominant-negative kinase mutant, block these steps and thereby prevent the synaptic degeneration produced by prions. Our results provide new insights into the pathogenesis of prion diseases, they uncover new drug targets for treating these diseases, and they allow us to compare prion diseases to other, more common neurodegenerative disorders like Alzheimer’s disease.
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Affiliation(s)
- Cheng Fang
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - Bei Wu
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - Nhat T. T. Le
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - Thibaut Imberdis
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - Robert C. C. Mercer
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
| | - David A. Harris
- Department of Biochemistry, Boston University School of Medicine, Boston MA, United States of America
- * E-mail:
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Enhanced extinction of aversive memories in mice lacking SPARC-related protein containing immunoglobulin domains 1 (SPIG1/FSTL4). Neurobiol Learn Mem 2018; 152:61-70. [PMID: 29783061 DOI: 10.1016/j.nlm.2018.05.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 05/11/2018] [Accepted: 05/16/2018] [Indexed: 01/23/2023]
Abstract
Brain-derived neurotrophic factor (BDNF) plays an important role in synaptic plasticity related to learning and memory. We previously reported that SPARC-related protein containing immunoglobulin domains 1 (SPIG1, also known as Follistatin-like protein 4, FSTL4) binds to pro-BDNF and negatively regulates BDNF maturation; however, its neurological functions, particularly in learning and memory, have not yet been elucidated. We herein examined the electrophysiological and behavioral phenotypes of Spig1-knockout (Spig1-KO) mice. Adult Spig1-KO mice exhibited greater excitability and facilitated long-term potentiation (LTP) in the CA1 region of hippocampal slices than age- and sex-matched wild-type (WT) mice. Facilitated LTP was reduced to the level of WT by the bath application of an anti-BDNF antibody to hippocampal slices. A step-through inhibitory avoidance learning paradigm revealed that the extinction of aversive memories was significantly enhanced in adult Spig1-KO mice, while they showed the normal acquisition of aversive memories; besides, spatial reference memory formation was also normal in the standard Morris water maze task. An intracerebroventricular (icv) injection of anti-BDNF in the process of extinction learning transiently induced the recurrence of aversive memories in Spig1-KO mice, but exerted no effects in WT mice. These results indicate a critical role for SPIG1 in BDNF-mediated synaptic plasticity in extinction of inhibitory avoidance memory.
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Mallik B, Kumar V. Regulation of actin-Spectrin cytoskeleton by ICA69 at the Drosophila neuromuscular junction. Commun Integr Biol 2017. [PMCID: PMC5824968 DOI: 10.1080/19420889.2017.1381806] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Bin-Amphiphysin-Rvs (BAR) domain containing proteins with their membrane deforming properties have emerged as key players in shaping up neuronal morphology and regulating cytoskeletal dynamics. However, the in vivo contexts in which BAR-domain proteins integrate membrane dynamics with cytoskeletal rearrangements remain poorly understood. Recently, we identified islet cell autoantigen 69 kDa as one of the N-BAR-domain containing proteins which regulate synaptic development and organization at the Drosophila neuromuscular junction. ICA69 genetically functions downstream of Rab2 to regulate synapse morphology. We found that ICA69 alters Spectrin level at the Drosophila NMJ, and redistributes actin regulatory proteins in cultured cells suggesting that ICA69 may regulate NMJ organization by regulating actin-Spectrin cytoskeleton. We propose a model in which ICA69 genetically interact with components of actin regulatory proteins for cytoskeleton dynamics to regulate NMJ development and synapse organization.
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Affiliation(s)
- Bhagaban Mallik
- Laboratory of Neurogenetics, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Madhya Pradesh, India
| | - Vimlesh Kumar
- Laboratory of Neurogenetics, Department of Biological Sciences, Indian Institute of Science Education and Research (IISER) Bhopal, Madhya Pradesh, India
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Synapse Formation in Monosynaptic Sensory-Motor Connections Is Regulated by Presynaptic Rho GTPase Cdc42. J Neurosci 2017; 36:5724-35. [PMID: 27225763 DOI: 10.1523/jneurosci.2146-15.2016] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2015] [Accepted: 04/13/2016] [Indexed: 01/04/2023] Open
Abstract
UNLABELLED Spinal reflex circuit development requires the precise regulation of axon trajectories, synaptic specificity, and synapse formation. Of these three crucial steps, the molecular mechanisms underlying synapse formation between group Ia proprioceptive sensory neurons and motor neurons is the least understood. Here, we show that the Rho GTPase Cdc42 controls synapse formation in monosynaptic sensory-motor connections in presynaptic, but not postsynaptic, neurons. In mice lacking Cdc42 in presynaptic sensory neurons, proprioceptive sensory axons appropriately reach the ventral spinal cord, but significantly fewer synapses are formed with motor neurons compared with wild-type mice. Concordantly, electrophysiological analyses show diminished EPSP amplitudes in monosynaptic sensory-motor circuits in these mutants. Temporally targeted deletion of Cdc42 in sensory neurons after sensory-motor circuit establishment reveals that Cdc42 does not affect synaptic transmission. Furthermore, addition of the synaptic organizers, neuroligins, induces presynaptic differentiation of wild-type, but not Cdc42-deficient, proprioceptive sensory neurons in vitro Together, our findings demonstrate that Cdc42 in presynaptic neurons is required for synapse formation in monosynaptic sensory-motor circuits. SIGNIFICANCE STATEMENT Group Ia proprioceptive sensory neurons form direct synapses with motor neurons, but the molecular mechanisms underlying synapse formation in these monosynaptic sensory-motor connections are unknown. We show that deleting Cdc42 in sensory neurons does not affect proprioceptive sensory axon targeting because axons reach the ventral spinal cord appropriately, but these neurons form significantly fewer presynaptic terminals on motor neurons. Electrophysiological analysis further shows that EPSPs are decreased in these mice. Finally, we demonstrate that Cdc42 is involved in neuroligin-dependent presynaptic differentiation of proprioceptive sensory neurons in vitro These data suggest that Cdc42 in presynaptic sensory neurons is essential for proper synapse formation in the development of monosynaptic sensory-motor circuits.
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20
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Wu B, McDonald AJ, Markham K, Rich CB, McHugh KP, Tatzelt J, Colby DW, Millhauser GL, Harris DA. The N-terminus of the prion protein is a toxic effector regulated by the C-terminus. eLife 2017; 6:e23473. [PMID: 28527237 PMCID: PMC5469617 DOI: 10.7554/elife.23473] [Citation(s) in RCA: 53] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 05/17/2017] [Indexed: 12/23/2022] Open
Abstract
PrPC, the cellular isoform of the prion protein, serves to transduce the neurotoxic effects of PrPSc, the infectious isoform, but how this occurs is mysterious. Here, using a combination of electrophysiological, cellular, and biophysical techniques, we show that the flexible, N-terminal domain of PrPC functions as a powerful toxicity-transducing effector whose activity is tightly regulated in cis by the globular C-terminal domain. Ligands binding to the N-terminal domain abolish the spontaneous ionic currents associated with neurotoxic mutants of PrP, and the isolated N-terminal domain induces currents when expressed in the absence of the C-terminal domain. Anti-PrP antibodies targeting epitopes in the C-terminal domain induce currents, and cause degeneration of dendrites on murine hippocampal neurons, effects that entirely dependent on the effector function of the N-terminus. NMR experiments demonstrate intramolecular docking between N- and C-terminal domains of PrPC, revealing a novel auto-inhibitory mechanism that regulates the functional activity of PrPC.
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Affiliation(s)
- Bei Wu
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Alex J McDonald
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Kathleen Markham
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, United States
| | - Celeste B Rich
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
| | - Kyle P McHugh
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, United States
| | - Jörg Tatzelt
- Department of Biochemistry of Neurodegenerative Diseases, Institute of Biochemistry and Pathobiochemistry, Ruhr University Bochum, Bochum, Germany
- Neurobiochemistry, Adolf Butenandt Institute, Ludwig Maximilians University, Munich, Germany
| | - David W Colby
- Department of Chemical and Biomolecular Engineering, University of Delaware, Newark, United States
| | - Glenn L Millhauser
- Department of Chemistry and Biochemistry, University of California, Santa Cruz, United States
| | - David A Harris
- Department of Biochemistry, Boston University School of Medicine, Boston, United States
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Ruan H, Gao J, Qi X, Tao Y, Guo X, Guo Z, Zheng L, Song Y, Liao Y, Shen W. Visual experience dependent regulation of neuronal structure and function by histone deacetylase 1 in developing Xenopus tectum in vivo. Dev Neurobiol 2017; 77:947-962. [PMID: 28033671 DOI: 10.1002/dneu.22480] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Revised: 12/13/2016] [Accepted: 12/16/2016] [Indexed: 01/28/2023]
Abstract
Histone deacetylase 1 (HDAC1) is thought to play pivotal roles in neurogenesis and neurodegeneration. However, the role of HDAC1 in neuronal growth and structural plasticity in the developing brain in vivo remains unclear. Here, we show that in the optic tectum of Xenopus laevis, HDAC1 knockdown dramatically decreased the frequency of AMPAR-mediated synaptic currents and increased the frequency of GABAAR-mediated currents, whereas HDAC1 overexpression significantly decreased the frequency of GABAAR-mediated synaptic currents. Both HDAC1 knockdown and overexpression adversely affected dendritic arbor growth and visual experience-dependent structural plasticity. Furthermore, HDAC1 knockdown decreased BDNF expression via a mechanism that involves acetylation of specific histone H4 residues at lysine K5. In particular, the deficits in dendritic growth and visually guided avoidance behavior in HDAC1-knockdown tadpoles could be rescued by acute tectal infusion of BDNF. These results establish a relationship between HDAC1 expression, histone H4 modification and BDNF signaling in the visual-experience dependent regulation of dendritic growth, structural plasticity and function in intact animals in vivo. © 2016 Wiley Periodicals, Inc. Develop Neurobiol 77: 947-962, 2017.
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Affiliation(s)
- Hangze Ruan
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Juanmei Gao
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Xianjie Qi
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Yi Tao
- Department of Neurosurgery, Nanjing Medical University Affiliated Jiangsu Cancer Hospital, Nanjing, Jiangsu, 210029, China
| | - Xia Guo
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Zhaoyi Guo
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Lijun Zheng
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Yaling Song
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Yuan Liao
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
| | - Wanhua Shen
- Zhejiang Key Laboratory of Organ Development and Regeneration, College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou, Zhejiang, 310036, China
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22
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Terry-Lorenzo RT, Torres VI, Wagh D, Galaz J, Swanson SK, Florens L, Washburn MP, Waites CL, Gundelfinger ED, Reimer RJ, Garner CC. Trio, a Rho Family GEF, Interacts with the Presynaptic Active Zone Proteins Piccolo and Bassoon. PLoS One 2016; 11:e0167535. [PMID: 27907191 PMCID: PMC5132261 DOI: 10.1371/journal.pone.0167535] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2016] [Accepted: 11/15/2016] [Indexed: 12/17/2022] Open
Abstract
Synaptic vesicles (SVs) fuse with the plasma membrane at a precise location called the presynaptic active zone (AZ). This fusion is coordinated by proteins embedded within a cytoskeletal matrix assembled at the AZ (CAZ). In the present study, we have identified a novel binding partner for the CAZ proteins Piccolo and Bassoon. This interacting protein, Trio, is a member of the Dbl family of guanine nucleotide exchange factors (GEFs) known to regulate the dynamic assembly of actin and growth factor dependent axon guidance and synaptic growth. Trio was found to interact with the C-terminal PBH 9/10 domains of Piccolo and Bassoon via its own N-terminal Spectrin repeats, a domain that is also critical for its localization to the CAZ. Moreover, our data suggest that regions within the C-terminus of Trio negatively regulate its interactions with Piccolo/Bassoon. These findings provide a mechanism for the presynaptic targeting of Trio and support a model in which Piccolo and Bassoon play a role in regulating neurotransmission through interactions with proteins, including Trio, that modulate the dynamic assembly of F-actin during cycles of synaptic vesicle exo- and endocytosis.
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Affiliation(s)
- Ryan T. Terry-Lorenzo
- Dept. of Psychiatry and Behavioral Science, Nancy Pritzker Laboratory, Stanford University, Palo Alto, California, United States of America
| | - Viviana I. Torres
- Dept. of Psychiatry and Behavioral Science, Nancy Pritzker Laboratory, Stanford University, Palo Alto, California, United States of America
- Centro de Envejecimiento y Regeneración (CARE), Departamento de Biología Celular y Molecular, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago, Chile, Alameda, Santiago, Chile
| | - Dhananjay Wagh
- Dept. of Psychiatry and Behavioral Science, Nancy Pritzker Laboratory, Stanford University, Palo Alto, California, United States of America
| | - Jose Galaz
- Dept. of Psychiatry and Behavioral Science, Nancy Pritzker Laboratory, Stanford University, Palo Alto, California, United States of America
| | - Selene K. Swanson
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Laurence Florens
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Michael P. Washburn
- Stowers Institute for Medical Research, Kansas City, Missouri, United States of America
| | - Clarissa L. Waites
- Dept. of Psychiatry and Behavioral Science, Nancy Pritzker Laboratory, Stanford University, Palo Alto, California, United States of America
| | - Eckart D. Gundelfinger
- Dept. of Neurochemistry and Molecular Biology, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Richard J. Reimer
- Dept. of Neurology and Neurological Sciences Stanford University and Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America
| | - Craig C. Garner
- Dept. of Psychiatry and Behavioral Science, Nancy Pritzker Laboratory, Stanford University, Palo Alto, California, United States of America
- German Centers for Neurodegenerative Diseases, Charité - Medical University, Berlin, Germany
- * E-mail:
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Actin-Dependent Alterations of Dendritic Spine Morphology in Shankopathies. Neural Plast 2016; 2016:8051861. [PMID: 27795858 PMCID: PMC5067329 DOI: 10.1155/2016/8051861] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 08/30/2016] [Indexed: 12/11/2022] Open
Abstract
Shank proteins (Shank1, Shank2, and Shank3) act as scaffolding molecules in the postsynaptic density of many excitatory neurons. Mutations in SHANK genes, in particular SHANK2 and SHANK3, lead to autism spectrum disorders (ASD) in both human and mouse models. Shank3 proteins are made of several domains-the Shank/ProSAP N-terminal (SPN) domain, ankyrin repeats, SH3 domain, PDZ domain, a proline-rich region, and the sterile alpha motif (SAM) domain. Via various binding partners of these domains, Shank3 is able to bind and interact with a wide range of proteins including modulators of small GTPases such as RICH2, a RhoGAP protein, and βPIX, a RhoGEF protein for Rac1 and Cdc42, actin binding proteins and actin modulators. Dysregulation of all isoforms of Shank proteins, but especially Shank3, leads to alterations in spine morphogenesis, shape, and activity of the synapse via altering actin dynamics. Therefore, here, we highlight the role of Shank proteins as modulators of small GTPases and, ultimately, actin dynamics, as found in multiple in vitro and in vivo models. The failure to mediate this regulatory role might present a shared mechanism in the pathophysiology of autism-associated mutations, which leads to dysregulation of spine morphogenesis and synaptic signaling.
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Jiang D, Du J, Zhang X, Zhou W, Zong L, Dong C, Chen K, Chen Y, Chen X, Jiang H. miR-124 promotes the neuronal differentiation of mouse inner ear neural stem cells. Int J Mol Med 2016; 38:1367-1376. [PMID: 28025992 PMCID: PMC5065304 DOI: 10.3892/ijmm.2016.2751] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2015] [Accepted: 08/08/2016] [Indexed: 12/31/2022] Open
Abstract
MicroRNAs (miRNAs or miRs) act as key regulators in neuronal development, synaptic morphogenesis and plasticity. However, their role in the neuronal differentiation of inner ear neural stem cells (NSCs) remains unclear. In this study, 6 miRNAs were selected and their expression patterns during the neuronal differentiation of inner ear NSCs were examined by RT-qPCR. We demonstrated that the culture of spiral ganglion stem cells present in the inner ears of newborn mice gave rise to neurons in vitro. The expression patterns of miR-124, miR-132, miR-134, miR-20a, miR-17-5p and miR-30a-5p were examined during a 14-day neuronal differentiation period. We found that miR-124 promoted the neuronal differentiation of and neurite outgrowth in mouse inner ear NSCs, and that the changes in the expression of tropomyosin receptor kinase B (TrkB) and cell division control protein 42 homolog (Cdc42) during inner ear NSC differentiation were associated with miR-124 expression. Our findings indicate that miR-124 plays a role in the neuronal differentiation of inner ear NSCs. This finding may lead to the development of novel strategies for restoring hearing in neurodegenerative diseases.
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Affiliation(s)
- Di Jiang
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Jintao Du
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Xuemei Zhang
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Wei Zhou
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Lin Zong
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Chang Dong
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Kaitian Chen
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Yu Chen
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Xihui Chen
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
| | - Hongyan Jiang
- Department of Otolaryngology, The First Affiliated Hospital, and Institute of Otorhinolaryngology, Sun Yat-sen University, Guangzhou, Guangdong 510080, P.R. China
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25
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Pinto MJ, Alves PL, Martins L, Pedro JR, Ryu HR, Jeon NL, Taylor AM, Almeida RD. The proteasome controls presynaptic differentiation through modulation of an on-site pool of polyubiquitinated conjugates. J Cell Biol 2016; 212:789-801. [PMID: 27022091 PMCID: PMC4810304 DOI: 10.1083/jcb.201509039] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Accepted: 02/24/2016] [Indexed: 11/22/2022] Open
Abstract
The intra-axonal events governing formation of presynaptic terminals are still poorly understood. Pinto et al. reveal a mechanism by which a localized decrease in proteasome degradation and resultant accumulation of polyubiquitinated proteins at nascent sites signal assembly of presynaptic terminals. Differentiation of the presynaptic terminal is a complex and rapid event that normally occurs in spatially specific axonal regions distant from the soma; thus, it is believed to be dependent on intra-axonal mechanisms. However, the full nature of the local events governing presynaptic assembly remains unknown. Herein, we investigated the involvement of the ubiquitin–proteasome system (UPS), the major degradative pathway, in the local modulation of presynaptic differentiation. We found that proteasome inhibition has a synaptogenic effect on isolated axons. In addition, formation of a stable cluster of synaptic vesicles onto a postsynaptic partner occurs in parallel to an on-site decrease in proteasome degradation. Accumulation of ubiquitinated proteins at nascent sites is a local trigger for presynaptic clustering. Finally, proteasome-related ubiquitin chains (K11 and K48) function as signals for the assembly of presynaptic terminals. Collectively, we propose a new axon-intrinsic mechanism for presynaptic assembly through local UPS inhibition. Subsequent on-site accumulation of proteins in their polyubiquitinated state triggers formation of presynapses.
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Affiliation(s)
- Maria J Pinto
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal PhD Program in Experimental Biology and Biomedicine, Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Pedro L Alves
- Instituto de Educação e Cidadania, 3770-033 Mamarrosa, Portugal
| | - Luís Martins
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Joana R Pedro
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal
| | - Hyun R Ryu
- Institute of Advanced Machinery and Design, Seoul National University, Seoul 151-744, Korea
| | - Noo Li Jeon
- Institute of Advanced Machinery and Design, Seoul National University, Seoul 151-744, Korea Department of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-744, Korea
| | - Anne M Taylor
- Joint Department of Biomedical Engineering, University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, NC 27599
| | - Ramiro D Almeida
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-517 Coimbra, Portugal Institute for Interdisciplinary Research, University of Coimbra, 3004-517 Coimbra, Portugal School of Allied Health Technologies, Polytechnic Institute of Porto, 4400-330 Vila Nova de Gaia, Portugal
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26
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Microtubule-associated protein 1B (MAP1B)-deficient neurons show structural presynaptic deficiencies in vitro and altered presynaptic physiology. Sci Rep 2016; 6:30069. [PMID: 27425640 PMCID: PMC4948024 DOI: 10.1038/srep30069] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 06/28/2016] [Indexed: 11/20/2022] Open
Abstract
Microtubule-associated protein 1B (MAP1B) is expressed predominantly during the early stages of development of the nervous system, where it regulates processes such as axonal guidance and elongation. Nevertheless, MAP1B expression in the brain persists in adult stages, where it participates in the regulation of the structure and physiology of dendritic spines in glutamatergic synapses. Moreover, MAP1B expression is also found in presynaptic synaptosomal preparations. In this work, we describe a presynaptic phenotype in mature neurons derived from MAP1B knockout (MAP1B KO) mice. Mature neurons express MAP1B, and its deficiency does not alter the expression levels of a subgroup of other synaptic proteins. MAP1B KO neurons display a decrease in the density of presynaptic and postsynaptic terminals, which involves a reduction in the density of synaptic contacts, and an increased proportion of orphan presynaptic terminals. Accordingly, MAP1B KO neurons present altered synaptic vesicle fusion events, as shown by FM4-64 release assay, and a decrease in the density of both synaptic vesicles and dense core vesicles at presynaptic terminals. Finally, an increased proportion of excitatory immature symmetrical synaptic contacts in MAP1B KO neurons was detected. Altogether these results suggest a novel role for MAP1B in presynaptic structure and physiology regulation in vitro.
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27
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Gu Y, Wang C, Li G, Huang LYM. EXPRESS: F-actin links Epac-PKC signaling to purinergic P2X3 receptors sensitization in dorsal root ganglia following inflammation. Mol Pain 2016; 12:12/0/1744806916660557. [PMID: 27385722 PMCID: PMC4955968 DOI: 10.1177/1744806916660557] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Sensitization of purinergic P2X3 receptors (P2X3Rs) contributes to the production of exaggerated nociceptive responses following inflammatory injury. We showed previously that prostaglandin E2 (PGE2) potentiates P2X3R-mediated ATP currents in dorsal root ganglion neurons isolated from both control and complete Freund’s adjuvant-induced inflamed rats. PGE2 potentiation of ATP currents depends only on PKA signaling in control neurons, but it depends on both PKA and PKC signaling in inflamed neurons. We further found that inflammation evokes an increase in exchange proteins directly activated by cAMP (Epacs) in dorsal root ganglions. This increase promotes the activation of PKC to produce a much enhanced PGE2 effect on ATP currents and to elicit Epac-dependent flinch nocifensive behavioral responses in complete Freund’s adjuvant rats. The link between Epac-PKC signaling and P2X3R sensitization remains unexplored. Here, we show that the activation of Epacs promotes the expression of phosphorylated PKC and leads to an increase in the cytoskeleton, F-actin, expression at the cell perimeter. Depolymerization of F-actin blocks PGE2-enhanced ATP currents and inhibits P2X3R-mediated nocifensive responses after inflammation. Thus, F-actin is dynamically involved in the Epac-PKC-dependent P2X3R sensitization. Furthermore, Epacs induce a PKC-dependent increase in the membrane expression of P2X3Rs. This increase is abolished by F-actin depolymerization, suggesting that F-actin mediates Epac-PKC signaling of P2X3R membrane expression. Thus, after inflammation, an Epac-PKC dependent increase in F-actin in dorsal root ganglion neurons enhances the membrane expression of P2X3Rs to bring about sensitization of P2X3Rs and abnormal pain behaviors.
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Affiliation(s)
- Yanping Gu
- University of Texas Medical Branch at Galveston
| | - Congying Wang
- University of Texas Medical Branch at GalvestonUniversity of Texas Medical Branch at Galveston
| | - Guangwen Li
- University of Texas Medical Branch at Galveston
| | - Li-Yen Mae Huang
- University of Texas Medical Branch at GalvestonUniversity of Texas Medical Branch at Galveston
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28
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Wagh D, Terry-Lorenzo R, Waites CL, Leal-Ortiz SA, Maas C, Reimer RJ, Garner CC. Piccolo Directs Activity Dependent F-Actin Assembly from Presynaptic Active Zones via Daam1. PLoS One 2015; 10:e0120093. [PMID: 25897839 PMCID: PMC4405365 DOI: 10.1371/journal.pone.0120093] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Accepted: 01/23/2015] [Indexed: 12/12/2022] Open
Abstract
The dynamic assembly of filamentous (F) actin plays essential roles in the assembly of presynaptic boutons, the fusion, mobilization and recycling of synaptic vesicles (SVs), and presynaptic forms of plasticity. However, the molecular mechanisms that regulate the temporal and spatial assembly of presynaptic F-actin remain largely unknown. Similar to other F-actin rich membrane specializations, presynaptic boutons contain a set of molecules that respond to cellular cues and trans-synaptic signals to facilitate activity-dependent assembly of F-actin. The presynaptic active zone (AZ) protein Piccolo has recently been identified as a key regulator of neurotransmitter release during SV cycling. It does so by coordinating the activity-dependent assembly of F-Actin and the dynamics of key plasticity molecules including Synapsin1, Profilin and CaMKII. The multidomain structure of Piccolo, its exquisite association with the AZ, and its ability to interact with a number of actin-associated proteins suggest that Piccolo may function as a platform to coordinate the spatial assembly of F-actin. Here we have identified Daam1, a Formin that functions with Profilin to drive F-actin assembly, as a novel Piccolo binding partner. We also found that within cells Daam1 activation promotes Piccolo binding, an interaction that can spatially direct the polymerization of F-Actin. Moreover, similar to Piccolo and Profilin, Daam1 loss of function impairs presynaptic-F-actin assembly in neurons. These data suggest a model in which Piccolo directs the assembly of presynaptic F-Actin from the AZ by scaffolding key actin regulatory proteins including Daam1.
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Affiliation(s)
- Dhananjay Wagh
- Department of Psychiatry and Behavioral Sciences, Nancy Pritzker Laboratory, Stanford University, Stanford, California, United States of America
| | - Ryan Terry-Lorenzo
- Department of Psychiatry and Behavioral Sciences, Nancy Pritzker Laboratory, Stanford University, Stanford, California, United States of America
| | - Clarissa L. Waites
- Department of Pathology and Cell Biology Columbia University New York, New York, United States of America
| | - Sergio A. Leal-Ortiz
- Department of Psychiatry and Behavioral Sciences, Nancy Pritzker Laboratory, Stanford University, Stanford, California, United States of America
| | - Christoph Maas
- Department of Psychiatry and Behavioral Sciences, Nancy Pritzker Laboratory, Stanford University, Stanford, California, United States of America
| | - Richard J. Reimer
- Department of Neurology and Neurological Sciences Stanford University and Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States of America
| | - Craig C. Garner
- Department of Psychiatry and Behavioral Sciences, Nancy Pritzker Laboratory, Stanford University, Stanford, California, United States of America
- * E-mail:
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29
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Song W, Jin XA. Brain-derived neurotrophic factor inhibits neuromuscular junction maturation in a cAMP-PKA-dependent way. Neurosci Lett 2015; 591:8-12. [PMID: 25681622 DOI: 10.1016/j.neulet.2015.02.019] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Revised: 02/07/2015] [Accepted: 02/10/2015] [Indexed: 11/28/2022]
Abstract
The development of neuromuscular junction (NMJ) is initiated by motor axon's contact with the skeletal muscle cell that is followed by synaptic maturation. Previous studies showed that brain-derived neurotrophic factor (BDNF) enhanced motoneurons' survival and growth but significantly inhibited synaptogenesis. Here, we report that chronic application of BDNF resulted in inhibition in the maturation process both physiologically and morphologically. The response to BDNF was mediated by its cognate receptor TrkB as the effects were abolished by Trk receptor inhibitor K252a. Protein kinase A (PKA) inhibitor reversed the effects of BDNF in inhibiting NMJ maturation. These results indicate that BDNF suppresses NMJ maturation through cAMP-PKA signaling pathway. Together with the previous studies, these results suggest that BDNF suppresses NMJ formation and maturation despite its effects in enhancing neuronal survival and growth.
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Affiliation(s)
- Wei Song
- Peking University Health Science Center, Beijing 100191, China; Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China.
| | - Xiwan Albert Jin
- Division of Life Science, Hong Kong University of Science and Technology, Hong Kong, China.
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30
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Zhang Y, Liu J, Luan G, Wang X. Inhibition of the small GTPase Cdc42 in regulation of epileptic-seizure in rats. Neuroscience 2015; 289:381-91. [PMID: 25595978 DOI: 10.1016/j.neuroscience.2014.12.059] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2014] [Revised: 12/16/2014] [Accepted: 12/16/2014] [Indexed: 11/28/2022]
Abstract
Altered expression of neuronal cytoskeletal proteins are known to play an important role in hyper-excitability of neurons in patients and animal models of epilepsy. Our previous work showed that cell division cycle 42 GTP-binding protein (Cdc42), a small GTPase of the Rho-subfamily, is significantly increased in the brain tissue of patients with temporal lobe epilepsy (TLE) and in the brain tissues of the epileptic model of rats. However, whether inhibition of Cdc42 can modify epileptic seizures has not been investigated. In this study, using a pilocarpine-induced epileptic model, we found that pretreatment with ML141, a specific inhibitor of Cdc42, reduces seizure severity. Whole-cell patch-clamp recording on CA1 pyramidal neurons in hippocampal slices from pilocarpine-induced epileptic model demonstrated that ML141 significantly inhibits the frequency of action potentials (APs), increases the amplitude and frequency of miniature inhibitory postsynaptic currents (mIPSCs), and increases the amplitude of evoked inhibitory postsynaptic currents (eIPSCs). However, ML141 did not have an impact on the miniature excitatory postsynaptic currents (mEPSCs). Our results are the first to indicate that Cdc42 plays an important role in the onset and progression of epileptic-seizures by regulating synaptic inhibition.
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Affiliation(s)
- Y Zhang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China
| | - J Liu
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China
| | - G Luan
- Center of Epilepsy, Beijing Institute for Brain Disorders, China
| | - X Wang
- Department of Neurology, The First Affiliated Hospital of Chongqing Medical University, Chongqing Key Laboratory of Neurology, 1 Youyi Road, Chongqing 400016, China.
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31
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Naro A, Russo M, Leo A, Bramanti P, Quartarone A, Calabrò RS. A Single Session of Repetitive Transcranial Magnetic Stimulation Over the Dorsolateral Prefrontal Cortex in Patients With Unresponsive Wakefulness Syndrome. Neurorehabil Neural Repair 2014; 29:603-13. [PMID: 25539781 DOI: 10.1177/1545968314562114] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background. The level of consciousness is regulated by the activation of the frontal parietal network since a disruption within this interregional cortical connectivity is associated with a consciousness breakdown. Objective. The primary aim of the present study was to examine the feasibility and the safety of a single session of repetitive transcranial magnetic stimulation (rTMS), delivered over the dorsolateral prefrontal cortex (DLPFC), in patients with unresponsive wakefulness syndrome (UWS). As a secondary aim, we investigated the efficacy of rTMS over DLPFC on cortico-cortical connectivity as tested with paired-pulse and dual-coil TMS techniques. Methods. We enrolled 10 healthy and 10 postanoxic UWS subjects. After clinical assessment, subjects underwent a single/paired pulse TMS paradigm evaluating the inhibitory and facilitatory intracortical circuits. In addition, several interregional interactions between primary motor, dorsal and ventral premotor, supplementary motor, and posterior parietal cortex areas were investigated by means of dual-coil TMS technique. These parameters were evaluated at baseline, immediately after, and 60 minutes after a protocol of 10-Hz rTMS delivered at the level of the DLPFC. Results. rTMS over DLPFC did not cause any adverse events. We showed that rTMS over DLPFC did not induce, at group level, any clinical improvement or intra-/intercortical connectivity changes. Interestingly, in 3 patients rTMS induced a significant, although transient, clinical improvement associated with a short-lasting reshaping of brain connectivity. Conclusions. We demonstrated that a single session of 10-Hz rTMS over the right DLPFC may transiently improve consciousness and partially restore the connectivity within several cortical areas in some patients with UWS.
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Affiliation(s)
- Antonino Naro
- IRCCS Centro Neurolesi “Bonino-Pulejo,” Messina, Italy
| | | | - Antonino Leo
- IRCCS Centro Neurolesi “Bonino-Pulejo,” Messina, Italy
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32
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Innervation by a GABAergic neuron depresses spontaneous release in glutamatergic neurons and unveils the clamping phenotype of synaptotagmin-1. J Neurosci 2014; 34:2100-10. [PMID: 24501351 DOI: 10.1523/jneurosci.3934-13.2014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The role of spontaneously occurring release events in glutamatergic and GABAergic neurons and their regulation is intensely debated. To study the interdependence of glutamatergic and GABAergic spontaneous release, we compared reciprocally connected "mixed" glutamatergic/GABAergic neuronal pairs from mice cultured on astrocyte islands with "homotypic" glutamatergic or GABAergic pairs and autaptic neurons. We measured mEPSC and mIPSC frequencies simultaneously from both neurons. Neuronal pairs formed both interneuronal synaptic and autaptic connections indiscriminately. We find that whereas mEPSC and mIPSC frequencies did not deviate between autaptic and synaptic connections, the frequency of mEPSCs in mixed pairs was strongly depressed compared with either autaptic neurons or glutamatergic pairs. Simultaneous imaging of synapses, or comparison to evoked release amplitudes, showed that this decrease was not caused by fewer active synapses. The mEPSC frequency was negatively correlated with the mIPSC frequency, indicating interdependence. Moreover, the reduction in mEPSC frequency was abolished when established pairs were exposed to bicuculline for 3 d, but not by long-term incubation with tetrodotoxin, indicating that spontaneous GABA release downregulates mEPSC frequency. Further investigations showed that knockout of synaptotagmin-1 did not affect mEPSC frequencies in either glutamatergic autaptic neurons or in glutamatergic pairs. However, in mixed glutamatergic/GABAergic pairs, mEPSC frequencies were increased by a factor of four in the synaptotagmin-1-null neurons, which is in line with data obtained from mixed cultures. The effect persisted after incubation with BAPTA-AM. We conclude that spontaneous GABA release exerts control over mEPSC release, and GABAergic innervation of glutamatergic neurons unveils the unclamping phenotype of the synaptotagmin-1-null neurons.
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Abstract
Much progress has been made in understanding how behavioral experience and neural activity can modify the structure and function of neural circuits during development and in the adult brain. Studies of physiological and molecular mechanisms underlying activity-dependent plasticity in animal models have suggested potential therapeutic approaches for a wide range of brain disorders in humans. Physiological and electrical stimulations as well as plasticity-modifying molecular agents may facilitate functional recovery by selectively enhancing existing neural circuits or promoting the formation of new functional circuits. Here, we review the advances in basic studies of neural plasticity mechanisms in developing and adult nervous systems and current clinical treatments that harness neural plasticity, and we offer perspectives on future development of plasticity-based therapy.
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Affiliation(s)
- Karunesh Ganguly
- Department of Neurology & Rehabilitation, San Francisco VA Medical Center, 4150 Clement Street, San Francisco, CA 94121, USA; Department of Neurology, University of California, San Francisco, 400 Parnassus Avenue, San Francisco, CA 94122, USA.
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Lu H, Park H, Poo MM. Spike-timing-dependent BDNF secretion and synaptic plasticity. Philos Trans R Soc Lond B Biol Sci 2013; 369:20130132. [PMID: 24298135 DOI: 10.1098/rstb.2013.0132] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
In acute hippocampal slices, we found that the presence of extracellular brain-derived neurotrophic factor (BDNF) is essential for the induction of spike-timing-dependent long-term potentiation (tLTP). To determine whether BDNF could be secreted from postsynaptic dendrites in a spike-timing-dependent manner, we used a reduced system of dissociated hippocampal neurons in culture. Repetitive pairing of iontophoretically applied glutamate pulses at the dendrite with neuronal spikes could induce persistent alterations of glutamate-induced responses at the same dendritic site in a manner that mimics spike-timing-dependent plasticity (STDP)-the glutamate-induced responses were potentiated and depressed when the glutamate pulses were applied 20 ms before and after neuronal spiking, respectively. By monitoring changes in the green fluorescent protein (GFP) fluorescence at the dendrite of hippocampal neurons expressing GFP-tagged BDNF, we found that pairing of iontophoretic glutamate pulses with neuronal spiking resulted in BDNF secretion from the dendrite at the iontophoretic site only when the glutamate pulses were applied within a time window of approximately 40 ms prior to neuronal spiking, consistent with the timing requirement of synaptic potentiation via STDP. Thus, BDNF is required for tLTP and BDNF secretion could be triggered in a spike-timing-dependent manner from the postsynaptic dendrite.
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Affiliation(s)
- Hui Lu
- Department of Molecular and Cell Biology, Helen Wills Neuroscience Institute, University of California, , Berkeley, CA 94720, USA
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Bagnato S, Boccagni C, Sant'angelo A, Fingelkurts AA, Fingelkurts AA, Galardi G. Emerging from an unresponsive wakefulness syndrome: Brain plasticity has to cross a threshold level. Neurosci Biobehav Rev 2013; 37:2721-36. [PMID: 24060531 DOI: 10.1016/j.neubiorev.2013.09.007] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 08/29/2013] [Accepted: 09/12/2013] [Indexed: 12/27/2022]
Affiliation(s)
- Sergio Bagnato
- Unit of Neurophysiology and Unit for Severe Acquired Brain Injury, Rehabilitation Department, Fondazione Istituto San Raffaele G. Giglio, Cefalù, PA, Italy.
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Stress and trauma: BDNF control of dendritic-spine formation and regression. Prog Neurobiol 2013; 112:80-99. [PMID: 24211850 DOI: 10.1016/j.pneurobio.2013.10.005] [Citation(s) in RCA: 142] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2013] [Revised: 10/16/2013] [Accepted: 10/17/2013] [Indexed: 12/21/2022]
Abstract
Chronic restraint stress leads to increases in brain derived neurotrophic factor (BDNF) mRNA and protein in some regions of the brain, e.g. the basal lateral amygdala (BLA) but decreases in other regions such as the CA3 region of the hippocampus and dendritic spine density increases or decreases in line with these changes in BDNF. Given the powerful influence that BDNF has on dendritic spine growth, these observations suggest that the fundamental reason for the direction and extent of changes in dendritic spine density in a particular region of the brain under stress is due to the changes in BDNF there. The most likely cause of these changes is provided by the stress initiated release of steroids, which readily enter neurons and alter gene expression, for example that of BDNF. Of particular interest is how glucocorticoids and mineralocorticoids tend to have opposite effects on BDNF gene expression offering the possibility that differences in the distribution of their receptors and of their downstream effects might provide a basis for the differential transcription of the BDNF genes. Alternatively, differences in the extent of methylation and acetylation in the epigenetic control of BDNF transcription are possible in different parts of the brain following stress. Although present evidence points to changes in BDNF transcription being the major causal agent for the changes in spine density in different parts of the brain following stress, steroids have significant effects on downstream pathways from the TrkB receptor once it is acted upon by BDNF, including those that modulate the density of dendritic spines. Finally, although glucocorticoids play a canonical role in determining BDNF modulation of dendritic spines, recent studies have shown a role for corticotrophin releasing factor (CRF) in this regard. There is considerable improvement in the extent of changes in spine size and density in rodents with forebrain specific knockout of CRF receptor 1 (CRFR1) even when the glucocorticoid pathways are left intact. It seems then that CRF does have a role to play in determining BDNF control of dendritic spines.
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Jeon SJ, Bak H, Seo J, Han SM, Lee SH, Han SH, Kwon KJ, Ryu JH, Cheong JH, Ko KH, Yang SI, Choi JW, Park SH, Shin CY. Oroxylin A Induces BDNF Expression on Cortical Neurons through Adenosine A2A Receptor Stimulation: A Possible Role in Neuroprotection. Biomol Ther (Seoul) 2013; 20:27-35. [PMID: 24116271 PMCID: PMC3792198 DOI: 10.4062/biomolther.2012.20.1.027] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 10/26/2011] [Accepted: 11/02/2011] [Indexed: 11/05/2022] Open
Abstract
Oroxylin A is a flavone isolated from a medicinal herb reported to be effective in reducing the inflammatory and oxidative stresses. It also modulates the production of brain derived neurotrophic factor (BDNF) in cortical neurons by the transactivation of cAMP response element-binding protein (CREB). As a neurotrophin, BDNF plays roles in neuronal development, differentiation, synaptogenesis, and neural protection from the harmful stimuli. Adenosine A2A receptor colocalized with BDNF in brain and the functional interaction between A2A receptor stimulation and BDNF action has been suggested. In this study, we investigated the possibility that oroxylin A modulates BDNF production in cortical neuron through the regulation of A2A receptor system. As ex-pected, CGS21680 (A2A receptor agonist) induced BDNF expression and release, however, an antagonist, ZM241385, prevented oroxylin A-induced increase in BDNF production. Oroxylin A activated the PI3K-Akt-GSK-3β signaling pathway, which is inhibited by ZM241385 and the blockade of the signaling pathway abolished the increase in BDNF production. The physiological roles of oroxylin A-induced BDNF production were demonstrated by the increased neurite extension as well as synapse formation from neurons. Overall, oroxylin A might regulate BDNF production in cortical neuron through A2A receptor stimulation, which promotes cellular survival, synapse formation and neurite extension.
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Affiliation(s)
- Se Jin Jeon
- Department of Pharmacology, College of Pharmacy and Research Institute of Pharmaceutical Sciences, Seoul National University, Seoul 151-742 ; Neuroscience Research Center, Institute for Advanced Biomedical Sciences
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Lesiak A, Pelz C, Ando H, Zhu M, Davare M, Lambert TJ, Hansen KF, Obrietan K, Appleyard SM, Impey S, Wayman GA. A genome-wide screen of CREB occupancy identifies the RhoA inhibitors Par6C and Rnd3 as regulators of BDNF-induced synaptogenesis. PLoS One 2013; 8:e64658. [PMID: 23762244 PMCID: PMC3675129 DOI: 10.1371/journal.pone.0064658] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2013] [Accepted: 04/16/2013] [Indexed: 12/16/2022] Open
Abstract
Neurotrophin-regulated gene expression is believed to play a key role in long-term changes in synaptic structure and the formation of dendritic spines. Brain-derived neurotrophic factor (BDNF) has been shown to induce increases in dendritic spine formation, and this process is thought to function in part by stimulating CREB-dependent transcriptional changes. To identify CREB-regulated genes linked to BDNF-induced synaptogenesis, we profiled transcriptional occupancy of CREB in hippocampal neurons. Interestingly, de novo motif analysis of hippocampal ChIP-Seq data identified a non-canonical CRE motif (TGGCG) that was enriched at CREB target regions and conferred CREB-responsiveness. Because cytoskeletal remodeling is an essential element of the formation of dendritic spines, within our screens we focused our attention on genes previously identified as inhibitors of RhoA GTPase. Bioinformatic analyses identified dozens of candidate CREB target genes known to regulate synaptic architecture and function. We showed that two of these, the RhoA inhibitors Par6C (Pard6A) and Rnd3 (RhoE), are BDNF-induced CREB-regulated genes. Interestingly, CREB occupied a cluster of non-canonical CRE motifs in the Rnd3 promoter region. Lastly, we show that BDNF-stimulated synaptogenesis requires the expression of Par6C and Rnd3, and that overexpression of either protein is sufficient to increase synaptogenesis. Thus, we propose that BDNF can regulate formation of functional synapses by increasing the expression of the RhoA inhibitors, Par6C and Rnd3. This study shows that genome-wide analyses of CREB target genes can facilitate the discovery of new regulators of synaptogenesis.
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Affiliation(s)
- Adam Lesiak
- Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Program in Neuroscience, Washington State University, Pullman, Washington, United States of America
| | - Carl Pelz
- Oregon Stem Cell Center, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Hideaki Ando
- Oregon Stem Cell Center, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Mingyan Zhu
- Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Program in Neuroscience, Washington State University, Pullman, Washington, United States of America
| | - Monika Davare
- Vollum Institute, Oregon Health and Science University, Portland, Oregon, United States of America
| | - Talley J. Lambert
- Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Program in Neuroscience, Washington State University, Pullman, Washington, United States of America
| | - Katelin F. Hansen
- Department of Neuroscience, Ohio State University, Columbus, Ohio, United States of America
| | - Karl Obrietan
- Department of Neuroscience, Ohio State University, Columbus, Ohio, United States of America
| | - Suzanne M. Appleyard
- Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Program in Neuroscience, Washington State University, Pullman, Washington, United States of America
| | - Soren Impey
- Oregon Stem Cell Center, Oregon Health and Science University, Portland, Oregon, United States of America
- Department of Pediatrics, Oregon Health and Science University, Portland, Oregon, United States of America
- * E-mail: (GAW); (SI)
| | - Gary A. Wayman
- Department of Veterinary and Comparative Anatomy, Pharmacology and Physiology, Program in Neuroscience, Washington State University, Pullman, Washington, United States of America
- * E-mail: (GAW); (SI)
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Li Z, Sun C, Zhang T, Mo J, Shi Q, Zhang X, Yuan M, Chen L, Mao X, Yu R, Zhou X. Geranylgeranyltransferase I mediates BDNF-induced synaptogenesis. J Neurochem 2013; 125:698-712. [PMID: 23534605 DOI: 10.1111/jnc.12249] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2012] [Revised: 03/21/2013] [Accepted: 03/22/2013] [Indexed: 12/22/2022]
Affiliation(s)
- Zhengwei Li
- The Graduate School; Xuzhou Medical College; Xuzhou Jiangsu China
| | - Chengdong Sun
- The Graduate School; Xuzhou Medical College; Xuzhou Jiangsu China
| | - Tao Zhang
- The Graduate School; Xuzhou Medical College; Xuzhou Jiangsu China
| | - Jianbing Mo
- The Graduate School; Xuzhou Medical College; Xuzhou Jiangsu China
| | - Qiong Shi
- Lab of Neurosurgery; Xuzhou Medical College; Xuzhou Jiangsu China
- Department of Neurosurgery; Affiliated Hospital of Xuzhou Medical College; Xuzhou Jiangsu China
- Key Laboratory of Brain Disease Biology; Affiliated Hospital of Xuzhou Medical College; Xuzhou Jiangsu China
| | - Xianfeng Zhang
- The Graduate School; Xuzhou Medical College; Xuzhou Jiangsu China
| | - Maochun Yuan
- The Graduate School; Xuzhou Medical College; Xuzhou Jiangsu China
| | - Long Chen
- The Graduate School; Xuzhou Medical College; Xuzhou Jiangsu China
| | - Xueqiang Mao
- The Graduate School; Xuzhou Medical College; Xuzhou Jiangsu China
| | - Rutong Yu
- Lab of Neurosurgery; Xuzhou Medical College; Xuzhou Jiangsu China
- Department of Neurosurgery; Affiliated Hospital of Xuzhou Medical College; Xuzhou Jiangsu China
- Key Laboratory of Brain Disease Biology; Affiliated Hospital of Xuzhou Medical College; Xuzhou Jiangsu China
| | - Xiuping Zhou
- Lab of Neurosurgery; Xuzhou Medical College; Xuzhou Jiangsu China
- Department of Neurosurgery; Affiliated Hospital of Xuzhou Medical College; Xuzhou Jiangsu China
- Key Laboratory of Brain Disease Biology; Affiliated Hospital of Xuzhou Medical College; Xuzhou Jiangsu China
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40
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PTEN inhibition prevents rat cortical neuron injury after hypoxia-ischemia. Neuroscience 2013; 238:242-51. [PMID: 23458710 DOI: 10.1016/j.neuroscience.2013.02.046] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2013] [Revised: 02/20/2013] [Accepted: 02/21/2013] [Indexed: 11/22/2022]
Abstract
Alterations in axon-dendrite polarity impair functional recovery in the developing CNS after hypoxia-ischemia (HI) injury. PTEN (phosphatase and tensin homolog deleted on chromosome 10) signaling pathway mediates the formation of neuronal polarity. However, its role in cerebral HI injury is not fully understood. In this study, we investigated the role of PTEN pathway in regulation of axon-dendrite polarity using an oxygen-glucose deprivation (OGD) model with rat cortical neurons. We found that the activity of PTEN and glycogen synthase kinase 3β (GSK-3β) was increased after OGD, along with the decrease of the activity in protein kinase B (Akt) and collapsin response mediator protein-2 (CRMP-2). Pretreatment with bpv, a potent inhibitor of PTEN, caused a decrease of the activity in PTEN and GSK-3β, and a significant increase of the activity in Akt and CRMP-2. Simultaneously, the morphological polarity of neurons was maintained and neuronal apoptosis was reduced. Moreover, inhibition of PTEN rescued vesicle recycling in axons. These findings suggested that the PTEN/Akt/GSK-3β/CRMP-2 pathway is involved in the regulation of axon-dendrite polarity, providing a novel route for protecting neurons following neonatal HI.
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Abstract
Brain-derived neurotrophic factor (BDNF)--a member of a small family of secreted proteins that includes nerve growth factor, neurotrophin 3 and neurotrophin 4--has emerged as a key regulator of neural circuit development and function. The expression, secretion and actions of BDNF are directly controlled by neural activity, and secreted BDNF is capable of mediating many activity-dependent processes in the mammalian brain, including neuronal differentiation and growth, synapse formation and plasticity, and higher cognitive functions. This Review summarizes some of the recent progress in understanding the cellular and molecular mechanisms underlying neurotrophin regulation of neural circuits. The focus of the article is on BDNF, as this is the most widely expressed and studied neurotrophin in the mammalian brain.
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Kim SE, Ko IG, Shin MS, Kim CJ, Jin BK, Hong HP, Jee YS. Treadmill exercise and wheel exercise enhance expressions of neutrophic factors in the hippocampus of lipopolysaccharide-injected rats. Neurosci Lett 2013; 538:54-9. [PMID: 23403101 DOI: 10.1016/j.neulet.2013.01.039] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2012] [Revised: 12/23/2012] [Accepted: 01/19/2013] [Indexed: 12/25/2022]
Abstract
Brain inflammation plays a pivotal role in the pathogenesis of chronic neurodegenerative disorders, including Alzheimer's disease and Parkinson's disease. We investigated the effects of treadmill exercise and wheel exercise on spatial learning ability in relation with long-term potentiation (LTP) using lipopolysaccharide-induced brain inflammation in the rats. Brain inflammation was induced by an injection of LPS into the cerebral ventricle. We found that brain inflammation impaired spatial learning ability and suppressed the induction of LTP in the hippocampus, as well as weakening expressions of brain-derived neurotrophic factor (BDNF) and its receptor tyrosine kinase B (Trk-B) with the phosphorylated cyclic AMP response element binding protein (p-CREB). Both treadmill exercise and wheel exercise significantly improved spatial learning ability deteriorated by brain inflammation. These effects can be ascribed to the long-lasting effect of exercise on LTP through enhancement of the expressions regarding BDNF, TrkB, and p-CREB. Treadmill exercise and wheel exercise exerted similar effects on these factors. We infer that exercise may alleviate brain inflammation-induced learning impairment.
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Affiliation(s)
- Sung-Eun Kim
- Department of Physiology, College of Medicine, Kyung Hee University, Dongdaemoon-gu, Seoul 130-701, Republic of Korea
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Bagnato S, Minafra L, Bravatà V, Boccagni C, Sant'angelo A, Castiglione A, Andriolo M, Lucca LF, De Tanti A, Pistarini C, Formisano R, Dolce G, Gelfi C, Galardi G. Brain-derived neurotrophic factor (Val66Met) polymorphism does not influence recovery from a post-traumatic vegetative state: a blinded retrospective multi-centric study. J Neurotrauma 2012; 29:2050-9. [PMID: 22708958 DOI: 10.1089/neu.2011.2184] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) is a neurotrophin that influences neuronal plasticity throughout life. Emergence from a vegetative state (VS) after a traumatic brain injury (TBI) implies that the brain undergoes plastic changes. A common polymorphism in the BDNF gene--BDNF Val66Met (referred to herein as BDNF(Met))--impairs cognitive function in healthy subjects. The aim of this study was to determine whether the BDNF(Met) polymorphism plays a role in the recovery of consciousness and cognitive functions in patients in a VS after a TBI. Fifty-three patients in a VS 1 month after a TBI were included in the study and genotyped for the BDNF(Met) polymorphism. Scores of levels of cognitive functioning (LCF) at 1, 3, 6, and 12 months post-TBI were retrospectively compared in patients without (Val group), and with (Met group), the BDNF(Met) polymorphism. The BDNF(Met) polymorphism was detected in 20 out of the 53 patients. The mean LCF scores in the Val and Met groups were 1.6±0.5 and 1.4±0.5 at 1 month, 2.3±0.7 and 2.5±1.2 at 3 months, 3.3±1.7 and 3.5±1.7 at 6 months, and 4±1.9 and 3.9±1.8 at 12 months, respectively (p>0.05). The percentages of patients in the Val and Met groups who emerged from the VS were 36.4% and 30% at 3 months, 66.3% and 70% at 6 months, and 70% and 87.5% at 12 months (p>0.05), respectively. These findings provide evidence that the BDNF(Met) polymorphism is not involved in cognitive improvement in patients with a VS following TBI. Future studies should focus on the role of other BDNF polymorphisms in the recovery from a VS.
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Affiliation(s)
- Sergio Bagnato
- Unit for Severe Acquired Brain Injuries, Fondazione Istituto "San Raffaele-G. Giglio " Cefalù, Italy.
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Mechanisms underlying induction of LTP-associated changes in short-term dynamics of transmission at immature synapses. Neuropharmacology 2012; 67:494-502. [PMID: 23246530 DOI: 10.1016/j.neuropharm.2012.11.019] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2012] [Revised: 11/21/2012] [Accepted: 11/25/2012] [Indexed: 01/11/2023]
Abstract
While the activity-dependent mechanisms guiding functional maturation of synaptic transmission postsynaptically are well characterized, less is known about the corresponding presynaptic mechanisms. Here we show that during the first postnatal week, a subset of CA3-CA1 synapses express postsynaptically induced LTP that is tightly associated with a robust decrease in synaptic facilitation, consistent with an increase in release probability (P(r)). The loss of facilitation is readily induced by physiologically relevant pairing protocols at immature synapses and is dependent on activation of NMDA-receptors but not L-type calcium channels. The putative pre- and postsynaptic components of neonatal LTP were distinguished in their downstream signaling requirements, PKC activity being selectively needed for the decrease in facilitation but not for synaptic potentiation per se. These data suggest that maturation of glutamatergic synapses involves a critical period during which presynaptic function is highly susceptible to activity-dependent regulation via a PKC-dependent mechanism.
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45
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Fu Y, Wu X, Lu J, Huang ZJ. Presynaptic GABA(B) Receptor Regulates Activity-Dependent Maturation and Patterning of Inhibitory Synapses through Dynamic Allocation of Synaptic Vesicles. Front Cell Neurosci 2012; 6:57. [PMID: 23227002 PMCID: PMC3512030 DOI: 10.3389/fncel.2012.00057] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2012] [Accepted: 11/12/2012] [Indexed: 11/13/2022] Open
Abstract
Accumulating evidence indicate that GABA regulates activity-dependent development of inhibitory synapses in the vertebrate brain, but the underlying mechanisms remain unclear. Here we combined live imaging of cortical GABAergic axons with single cell genetic manipulation to dissect the role of presynaptic GABAB receptors (GABABRs) in inhibitory synapse formation in mouse. Developing GABAergic axons form a significant number of transient boutons but only a subset was stabilized. Synaptic vesicles in these nascent boutons are often highly mobile in the course of tens of minutes. Activation of presynaptic GABABRs stabilized mobile vesicles in nascent boutons through the local enhancement of actin polymerization. Inactivation of GABABRs in developing basket interneurons resulted in aberrant pattern of bouton size distribution, reduced bouton density and reduced axon branching, as well as reduced frequency of miniature inhibitory currents in postsynaptic pyramidal neurons. These results suggest that GABABRs along developing inhibitory axons act as a local sensor of GABA release and promote presynaptic maturation through increased recruitment of mobile vesicle pools. Such release-dependent validation and maturation of nascent terminals is well suited to sculpt the pattern of synapse formation and distribution along axon branches.
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Affiliation(s)
- Yu Fu
- Cold Spring Harbor Laboratory Cold Spring Harbor, NY, USA ; Program in Neuroscience, Stony Brook University Stony Brook, NY, USA
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46
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Franz MB, Daube S, Keck C, Sator M, Pietrowski D. Small GTPases are involved in sprout formation in human granulosa lutein cells. Arch Gynecol Obstet 2012. [DOI: 10.1007/s00404-012-2642-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
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Gilks WP, Hill M, Gill M, Donohoe G, Corvin AP, Morris DW. Functional investigation of a schizophrenia GWAS signal at the CDC42 gene. World J Biol Psychiatry 2012; 13:550-4. [PMID: 22385474 DOI: 10.3109/15622975.2012.666359] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVES SNP rs2473277 upstream of the cell division cycle 42 (CDC42) gene was associated with schizophrenia in a recent genome-wide association study (GWAS). Reduced expression of CDC42 in schizophrenia has previously been reported. Our objective was to test whether the associated SNP affected CDC42 expression. METHODS Two available SNP × gene expression datasets were accessed to test the effect of rs2473277 on CDC42 expression: (i) the mRNA by SNP Browser, which presents results of a genome-wide linkage study of gene expression, and (ii) the Genevar HapMap expression dataset. rs2473277 is in strong linkage disequilibrium (LD) with the SNP rs2473307 (r(2) =0.96), which is predicted to affect transcription factor binding. rs2473307 was directly tested for allelic effects on gene expression using a gene reporter assay in a human neuronal cell line. RESULTS In both datasets, the schizophrenia risk allele at rs2473277 was associated with a reduction in CDC42 mRNA levels. In the reporter gene assay the risk allele at rs2473307 similarly reduced gene expression. CONCLUSIONS We found evidence that rs2473307, in strong LD with the schizophrenia associated SNP rs2473277, is a functional variant at CDC42 that may increase risk for schizophrenia by reducing expression of CDC42.
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Affiliation(s)
- William P Gilks
- Neuropsychiatric Genetics Research Group, Department of Psychiatry and Institute of Molecular Medicine, Trinity College Dublin, Dublin, Ireland
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Laudes T, Meis S, Munsch T, Lessmann V. Impaired transmission at corticothalamic excitatory inputs and intrathalamic GABAergic synapses in the ventrobasal thalamus of heterozygous BDNF knockout mice. Neuroscience 2012; 222:215-27. [DOI: 10.1016/j.neuroscience.2012.07.005] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2012] [Revised: 06/27/2012] [Accepted: 07/02/2012] [Indexed: 01/08/2023]
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49
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Qiang M, Wu B, Liu Y. A brief review on current progress in neuroscience in China. SCIENCE CHINA-LIFE SCIENCES 2012; 54:1156-9. [PMID: 22227910 DOI: 10.1007/s11427-011-4261-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 11/15/2011] [Indexed: 01/01/2023]
Affiliation(s)
- Min Qiang
- State Key Laboratory of Brain and Cognitive Science, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
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McDonald JW, Sadowsky CL, Stampas A. The changing field of rehabilitation: optimizing spontaneous regeneration and functional recovery. HANDBOOK OF CLINICAL NEUROLOGY 2012; 109:317-336. [PMID: 23098722 DOI: 10.1016/b978-0-444-52137-8.00020-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
For neurorehabilitation of patients with spinal cord injury (SCI), the traditional emphasis on social adaptation is being expanded to include strategies that promote plasticity and regeneration in the central nervous system. Such strategies are needed to optimize recovery of neurological function. For example, the known dependence of most cellular processes on physical activity has led to the novel concept that activity is important in neural repair. This hypothesis has given rise to activity-based restoration therapies (ABRT), which aim to optimize neural activity in the damaged spinal cord, particularly below the injury level. Here, we review the basic science and clinical evidence supporting the lifelong use of ABRT for recovery from spinal cord injury. We define and describe ABRT, and discuss its components, its clinical applications, its relationship to medical management of spinal cord injury, and the potential influences of medications on recovery. We also discuss the health benefits of ABRT under physiological and pathological conditions. We stress that lifelong ABRT is required to optimize return of function and to allow patients to benefit from any "cures" that will be discovered.
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Affiliation(s)
- John W McDonald
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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