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Han X, Hu X, Jin W, Liu G. Dietary nutrition, intestinal microbiota dysbiosis and post-weaning diarrhea in piglets. ANIMAL NUTRITION (ZHONGGUO XU MU SHOU YI XUE HUI) 2024; 17:188-207. [PMID: 38800735 PMCID: PMC11126776 DOI: 10.1016/j.aninu.2023.12.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2023] [Revised: 12/12/2023] [Accepted: 12/21/2023] [Indexed: 05/29/2024]
Abstract
Weaning is a critical transitional point in the life cycle of piglets. Early weaning can lead to post-weaning syndrome, destroy the intestinal barrier function and microbiota homeostasis, cause diarrhea and threaten the health of piglets. The nutritional components of milk and solid foods consumed by newborn animals can affect the diversity and structure of their intestinal microbiota, and regulate post-weaning diarrhea in piglets. Therefore, this paper reviews the effects and mechanisms of different nutrients, including protein, dietary fiber, dietary fatty acids and dietary electrolyte balance, on diarrhea and health of piglets by regulating intestinal function. Protein is an essential nutrient for the growth of piglets; however, excessive intake will cause many harmful effects, such as allergic reactions, intestinal barrier dysfunction and pathogenic growth, eventually aggravating piglet diarrhea. Dietary fiber is a nutrient that alleviates post-weaning diarrhea in piglets, which is related to its promotion of intestinal epithelial integrity, microbial homeostasis and the production of short-chain fatty acids. In addition, dietary fatty acids and dietary electrolyte balance can also facilitate the growth, function and health of piglets by regulating intestinal epithelial function, immune system and microbiota. Thus, a targeted control of dietary components to promote the establishment of a healthy bacterial community is a significant method for preventing nutritional diarrhea in weaned piglets.
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Affiliation(s)
- Xuebing Han
- Department of Urology, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, China
- College of Bioscience and Biotechnology, Hunan Agricultural University, Hunan Provincial Engineering Research Center of Applied Microbial Resources Development for Livestock and Poultry, Changsha, Hunan 410125, China
| | - Xiangdong Hu
- State Key Laboratory of Subtropical Silviculture, Zhejiang A&F University, Hangzhou 311300, China
| | - Wei Jin
- Department of Urology, Shengjing Hospital of China Medical University, Shenyang, Liaoning 110004, China
| | - Gang Liu
- College of Bioscience and Biotechnology, Hunan Agricultural University, Hunan Provincial Engineering Research Center of Applied Microbial Resources Development for Livestock and Poultry, Changsha, Hunan 410125, China
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2
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Stepan J, Heinz DE, Dethloff F, Wiechmann S, Martinelli S, Hafner K, Ebert T, Junglas E, Häusl AS, Pöhlmann ML, Jakovcevski M, Pape JC, Zannas AS, Bajaj T, Hermann A, Ma X, Pavenstädt H, Schmidt MV, Philipsen A, Turck CW, Deussing JM, Rammes G, Robinson AC, Payton A, Wehr MC, Stein V, Murgatroyd C, Kremerskothen J, Kuster B, Wotjak CT, Gassen NC. Inhibiting Hippo pathway kinases releases WWC1 to promote AMPAR-dependent synaptic plasticity and long-term memory in mice. Sci Signal 2024; 17:eadj6603. [PMID: 38687825 DOI: 10.1126/scisignal.adj6603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2023] [Accepted: 04/11/2024] [Indexed: 05/02/2024]
Abstract
The localization, number, and function of postsynaptic AMPA-type glutamate receptors (AMPARs) are crucial for synaptic plasticity, a cellular correlate for learning and memory. The Hippo pathway member WWC1 is an important component of AMPAR-containing protein complexes. However, the availability of WWC1 is constrained by its interaction with the Hippo pathway kinases LATS1 and LATS2 (LATS1/2). Here, we explored the biochemical regulation of this interaction and found that it is pharmacologically targetable in vivo. In primary hippocampal neurons, phosphorylation of LATS1/2 by the upstream kinases MST1 and MST2 (MST1/2) enhanced the interaction between WWC1 and LATS1/2, which sequestered WWC1. Pharmacologically inhibiting MST1/2 in male mice and in human brain-derived organoids promoted the dissociation of WWC1 from LATS1/2, leading to an increase in WWC1 in AMPAR-containing complexes. MST1/2 inhibition enhanced synaptic transmission in mouse hippocampal brain slices and improved cognition in healthy male mice and in male mouse models of Alzheimer's disease and aging. Thus, compounds that disrupt the interaction between WWC1 and LATS1/2 might be explored for development as cognitive enhancers.
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Affiliation(s)
- Jens Stepan
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany
- Department of Obstetrics and Gynecology, Paracelsus Medical University, 5020 Salzburg, Austria
- Department of Gynecology and Obstetrics, Technical University of Munich, 81675 Munich, Germany
| | - Daniel E Heinz
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany
- Research Group Neuronal Plasticity, Max Planck Institute of Psychiatry, 80804 Munich, Germany
- Max Planck School of Cognition, 04103 Leipzig, Germany
| | - Frederik Dethloff
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany
- Metabolomics Core Facility, Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
| | - Svenja Wiechmann
- Chair of Proteomics and Bioanalytics, Technical University of Munich, 85354 Freising, Germany
- German Cancer Consortium (DKTK), 80336 Munich, Germany
- German Cancer Center (DKFZ), 69120 Heidelberg, Germany
| | - Silvia Martinelli
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Kathrin Hafner
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Tim Ebert
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany
- Research Group Neuronal Plasticity, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Ellen Junglas
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany
| | - Alexander S Häusl
- Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Max L Pöhlmann
- Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Mira Jakovcevski
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Julius C Pape
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Anthony S Zannas
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514, USA
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC 27514, USA
| | - Thomas Bajaj
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany
| | - Anke Hermann
- Department of Medicine D, Division of General Internal Medicine, Nephrology, and Rheumatology, University Hospital Münster, 48149 Münster, Germany
| | - Xiao Ma
- Research Group Cell Signalling, Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, 80336 Munich, Germany
| | - Hermann Pavenstädt
- Department of Medicine D, Division of General Internal Medicine, Nephrology, and Rheumatology, University Hospital Münster, 48149 Münster, Germany
| | - Mathias V Schmidt
- Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Alexandra Philipsen
- Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany
| | - Christoph W Turck
- Proteomics and Biomarkers, Max Planck Institute of Psychiatry, 80804 Munich, Germany
- Key Laboratory of Animal Models and Human Disease Mechanisms of the Chinese Academy of Sciences & Yunnan Province, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, 650223 Yunnan, China
| | - Jan M Deussing
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804 Munich, Germany
- Research Group Molecular Neurogenetics, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Gerhard Rammes
- Department of Anaesthesiology and Intensive Care Medicine, Klinikum rechts der Isar, Technical University of Munich, 81675 Munich, Germany
| | - Andrew C Robinson
- Division of Neuroscience, Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, Salford Royal Hospital, Salford M6 8HD, UK
- Geoffrey Jefferson Brain Research Centre, Manchester Academic Health Science Centre (MAHSC), Salford M6 8HD, UK
| | - Antony Payton
- Division of Informatics, Imaging and Data Sciences, University of Manchester, Manchester M13 9NT, UK
| | - Michael C Wehr
- Research Group Cell Signalling, Department of Psychiatry and Psychotherapy, LMU University Hospital, LMU Munich, 80336 Munich, Germany
| | - Valentin Stein
- Institute of Physiology II, Medical Faculty University of Bonn, 53115 Bonn, Germany
| | | | - Joachim Kremerskothen
- Department of Medicine D, Division of General Internal Medicine, Nephrology, and Rheumatology, University Hospital Münster, 48149 Münster, Germany
| | - Bernhard Kuster
- Chair of Proteomics and Bioanalytics, Technical University of Munich, 85354 Freising, Germany
- German Cancer Consortium (DKTK), 80336 Munich, Germany
- German Cancer Center (DKFZ), 69120 Heidelberg, Germany
- Bavarian Center for Biomolecular Mass Spectrometry, Technical University of Munich, 85354 Freising, Germany
| | - Carsten T Wotjak
- Research Group Neuronal Plasticity, Max Planck Institute of Psychiatry, 80804 Munich, Germany
- Central Nervous System Diseases Research, Boehringer Ingelheim Pharmaceuticals GmbH & Co. KG, 88397 Biberach an der Riß, Germany
| | - Nils C Gassen
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany
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3
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Falahati H, Wu Y, De Camilli P. Ectopic Reconstitution of a Spine-Apparatus Like Structure Provides Insight into Mechanisms Underlying Its Formation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.16.589782. [PMID: 38659799 PMCID: PMC11042382 DOI: 10.1101/2024.04.16.589782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
The endoplasmic reticulum (ER) is a continuous cellular endomembrane network that displays focal specializations. Most notable examples of such specializations include the spine apparatus of neuronal dendrites, and the cisternal organelle of axonal initial segments. Both organelles exhibit stacks of smooth ER sheets with a narrow lumen and interconnected by a dense protein matrix. The actin-binding protein synaptopodin is required for their formation. Here, we report that expression in non-neuronal cells of a synaptopodin construct targeted to the ER is sufficient to generate stacked ER cisterns resembling the spine apparatus with molecular properties distinct from the surrounding ER. Cisterns within these stacks are connected to each other by an actin-based matrix that contains proteins also found at the spine apparatus of neuronal spines. These findings reveal a critical role of a synaptopodin-dependent actin matrix in generating cisternal stacks. These ectopically generated structures provide insight into spine apparatus morphogenesis.
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Affiliation(s)
- Hanieh Falahati
- HHMI; Departments of Neuroscience and Cell Biology; Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University School of Medicine, 100 College Street, New Haven, 06511, CT, USA
| | - Yumei Wu
- HHMI; Departments of Neuroscience and Cell Biology; Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University School of Medicine, 100 College Street, New Haven, 06511, CT, USA
| | - Pietro De Camilli
- HHMI; Departments of Neuroscience and Cell Biology; Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University School of Medicine, 100 College Street, New Haven, 06511, CT, USA
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4
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Prasansuklab A, Sukjamnong S, Theerasri A, Hu VW, Sarachana T, Tencomnao T. Transcriptomic analysis of glutamate-induced HT22 neurotoxicity as a model for screening anti-Alzheimer's drugs. Sci Rep 2023; 13:7225. [PMID: 37142620 PMCID: PMC10160028 DOI: 10.1038/s41598-023-34183-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Accepted: 04/25/2023] [Indexed: 05/06/2023] Open
Abstract
Glutamate-induced neurotoxicity in the HT22 mouse hippocampal neuronal cell line has been recognized as a valuable cell model for the study of neurotoxicity associated with neurodegenerative diseases including Alzheimer's disease (AD). However, the relevance of this cell model for AD pathogenesis and preclinical drug screening remains to be more elucidated. While there is increasing use of this cell model in a number of studies, relatively little is known about its underlying molecular signatures in relation to AD. Here, our RNA sequencing study provides the first transcriptomic and network analyses of HT22 cells following glutamate exposure. Several differentially expressed genes (DEGs) and their relationships specific to AD were identified. Additionally, the usefulness of this cell model as a drug screening system was assessed by determining the expression of those AD-associated DEGs in response to two medicinal plant extracts, Acanthus ebracteatus and Streblus asper, that have been previously shown to be protective in this cell model. In summary, the present study reports newly identified AD-specific molecular signatures in glutamate-injured HT22 cells, suggesting that this cell can be a valuable model system for the screening and evaluation of new anti-AD agents, particularly from natural products.
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Affiliation(s)
- Anchalee Prasansuklab
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Chulalongkorn University, Bangkok, 10330, Thailand
- College of Public Health Sciences, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Suporn Sukjamnong
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330, Thailand
- SYstems Neuroscience of Autism and PSychiatric Disorders (SYNAPS) Research Unit, Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Atsadang Theerasri
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Chulalongkorn University, Bangkok, 10330, Thailand
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Valerie W Hu
- Department of Biochemistry and Molecular Medicine, The George Washington University School of Medicine and Health Sciences, The George Washington University, Washington, DC, USA
| | - Tewarit Sarachana
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330, Thailand
- SYstems Neuroscience of Autism and PSychiatric Disorders (SYNAPS) Research Unit, Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Tewin Tencomnao
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Chulalongkorn University, Bangkok, 10330, Thailand.
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, 10330, Thailand.
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5
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Konietzny A, Wegmann S, Mikhaylova M. The endoplasmic reticulum puts a new spin on synaptic tagging. Trends Neurosci 2023; 46:32-44. [PMID: 36428191 DOI: 10.1016/j.tins.2022.10.012] [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: 08/18/2022] [Revised: 10/12/2022] [Accepted: 10/31/2022] [Indexed: 11/23/2022]
Abstract
The heterogeneity of the endoplasmic reticulum (ER) makes it a versatile platform for a broad range of homeostatic processes, ranging from calcium regulation to synthesis and trafficking of proteins and lipids. It is not surprising that neurons use this organelle to fine-tune synaptic properties and thereby provide specificity to synaptic inputs. In this review, we discuss the mechanisms that enable activity-dependent ER recruitment into dendritic spines, with a focus on molecular mechanisms that mediate transport and retention of the ER in spines. The role of calcium signaling in spine ER, synaptopodin 'tagging' of active synapses, and the formation of the spine apparatus (SA) are highlighted. Finally, we discuss the role of liquid-liquid phase separation as a possible driving force in these processes.
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Affiliation(s)
- Anja Konietzny
- AG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin, Germany; Guest Group 'Neuronal Protein Transport', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
| | - Susanne Wegmann
- German Center for Neurodegenerative Diseases (DZNE), Berlin, Germany
| | - Marina Mikhaylova
- AG Optobiology, Institute of Biology, Humboldt Universität zu Berlin, Berlin, Germany; Guest Group 'Neuronal Protein Transport', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, Hamburg, Germany.
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6
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Stepan J, Heinz DE, Dethloff F, Bajaj T, Zellner A, Hafner K, Wiechmann S, Mackert S, Mecdad Y, Rabenstein M, Ebert T, Martinelli S, Häusl AS, Pöhlmann ML, Hermann A, Ma X, Pavenstädt H, Schmidt MV, Philipsen A, Turck CW, Deussing JM, Kuster B, Wehr MC, Stein V, Kremerskothen J, Wotjak CT, Gassen NC. Hippo-released WWC1 facilitates AMPA receptor regulatory complexes for hippocampal learning. Cell Rep 2022; 41:111766. [PMID: 36476872 DOI: 10.1016/j.celrep.2022.111766] [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: 04/08/2022] [Revised: 08/23/2022] [Accepted: 11/10/2022] [Indexed: 12/12/2022] Open
Abstract
Learning and memory rely on changes in postsynaptic glutamergic α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-type receptor (AMPAR) number, spatial organization, and function. The Hippo pathway component WW and C2 domain-containing protein 1 (WWC1) regulates AMPAR surface expression and impacts on memory performance. However, synaptic binding partners of WWC1 and its hierarchical position in AMPAR complexes are largely unclear. Using cell-surface proteomics in hippocampal tissue of Wwc1-deficient mice and by generating a hippocampus-specific interactome, we show that WWC1 is a major regulatory platform in AMPAR signaling networks. Under basal conditions, the Hippo pathway members WWC1 and large tumor-suppressor kinase (LATS) are associated, which might prevent WWC1 effects on synaptic proteins. Reduction of WWC1/LATS binding through a point mutation at WWC1 elevates the abundance of WWC1 in AMPAR complexes and improves hippocampal-dependent learning and memory. Thus, uncoupling of WWC1 from the Hippo pathway to AMPAR-regulatory complexes provides an innovative strategy to enhance synaptic transmission.
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Affiliation(s)
- Jens Stepan
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany; Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany; Department of Obstetrics and Gynecology, Paracelsus Medical University, 5020 Salzburg, Austria.
| | - Daniel E Heinz
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany; Research Group Neuronal Plasticity, Max Planck Institute of Psychiatry, 80804 Munich, Germany; Max Planck School of Cognition, 04103 Leipzig, Germany
| | - Frederik Dethloff
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany; Metabolomics Core Facility, Max Planck Institute for Biology of Ageing, 50931 Cologne, Germany
| | - Thomas Bajaj
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany
| | - Andreas Zellner
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany; Chair of Proteomics and Bioanalytics, Technical University of Munich, 85354 Freising, Germany
| | - Kathrin Hafner
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Svenja Wiechmann
- Chair of Proteomics and Bioanalytics, Technical University of Munich, 85354 Freising, Germany; German Cancer Consortium (DKTK), 80336 Munich, Germany; German Cancer Center (DKFZ), 69120 Heidelberg, Germany
| | - Sarah Mackert
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany
| | - Yara Mecdad
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany
| | - Michael Rabenstein
- Institute of Physiology II, University Hospital Bonn, 53115 Bonn, Germany
| | - Tim Ebert
- Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany; Research Group Neuronal Plasticity, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Silvia Martinelli
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Alexander S Häusl
- Department Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804 Munich, Germany; Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Maximilian L Pöhlmann
- Department Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804 Munich, Germany; Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Anke Hermann
- Department of Medicine D, Division of General Internal Medicine, Nephrology, and Rheumatology, University Hospital Münster, 48149 Münster, Germany
| | - Xiao Ma
- Research Group Signal Transduction, Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, 80336 Munich, Germany
| | - Hermann Pavenstädt
- Department of Medicine D, Division of General Internal Medicine, Nephrology, and Rheumatology, University Hospital Münster, 48149 Münster, Germany
| | - Mathias V Schmidt
- Department Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804 Munich, Germany; Research Group Neurobiology of Stress Resilience, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Alexandra Philipsen
- Clinic for Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany
| | - Chris W Turck
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Jan M Deussing
- Research Group Molecular Neurogenetics, Max Planck Institute of Psychiatry, 80804 Munich, Germany
| | - Bernhard Kuster
- Chair of Proteomics and Bioanalytics, Technical University of Munich, 85354 Freising, Germany; German Cancer Consortium (DKTK), 80336 Munich, Germany; German Cancer Center (DKFZ), 69120 Heidelberg, Germany; Bavarian Center for Biomolecular Mass Spectrometry, Technical University of Munich, 85354 Freising, Germany
| | - Michael C Wehr
- Research Group Signal Transduction, Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, 80336 Munich, Germany
| | - Valentin Stein
- Institute of Physiology II, University Hospital Bonn, 53115 Bonn, Germany
| | - Joachim Kremerskothen
- Department of Medicine D, Division of General Internal Medicine, Nephrology, and Rheumatology, University Hospital Münster, 48149 Münster, Germany
| | - Carsten T Wotjak
- Research Group Neuronal Plasticity, Max Planck Institute of Psychiatry, 80804 Munich, Germany; Central Nervous System Diseases Research, Boehringer-Ingelheim Pharma GmbH & Co KG, 88400 Biberach, Germany.
| | - Nils C Gassen
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804 Munich, Germany; Research Group Neurohomeostasis, Department of Psychiatry and Psychotherapy, University Hospital Bonn, 53127 Bonn, Germany.
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7
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Guo XR, He CW, Gao H, Hua RX, Liang C, Du YX, Shang HW, Lu X, Xu JD. Insight into role of short chain fatty acids in regulating intestinal mucosal barrier and alleviating inflammatory bowel disease. Shijie Huaren Xiaohua Zazhi 2022; 30:928-940. [DOI: 10.11569/wcjd.v30.i21.928] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
In recent years, the importance of intestinal microbiota and its metabolites in maintaining the human intestinal environment has been gradually revealed. Therefore, short chain fatty acids (SCFAs), as the metabolites produced by the intestinal microbiota, play a momentous part in regulating the balance between the function and morphology of the mucosal barrier, regulating the proliferation and differentiation of mucosal cells, protecting the integrity and permeability of the mucosal barrier, and maintainingthe stability of tight junctions. Inflammatory bowel disease (IBD) is a chronic, inflammatory condition of the gastrointestinal tract, associated with a disturbance of intestinal barrier function and dysregulation of the intestinal immune responses, the etiology and pathogenesis of which, however, are not yet fully uncovered. Animal models and human studies have corroborated the contribution of SCFAs in enhancing the barrier function through protective effects. This review will summarize the potential role of SCFAs in IBD with regard to regulating intestinal function, hoping to provide a new target for clinical treatment of IBD.
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Affiliation(s)
- Xue-Ran Guo
- 2019 Clinical Medicine, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Cheng-Wei He
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Han Gao
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Rong-Xuan Hua
- 2020 Clinical Medicine of "5+3" Program, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Chen Liang
- 2019 Clinical Medicine, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Yi-Xuan Du
- 2020 Oral Medicine of "5+3" Program, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Hong-Wei Shang
- Teaching Laboratory of Morphology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Xin Lu
- Teaching Laboratory of Morphology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| | - Jing-Dong Xu
- Department of Physiology and Pathophysiology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
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8
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Falahati H, Wu Y, Feuerer V, Simon HG, De Camilli P. Proximity proteomics of synaptopodin provides insight into the molecular composition of the spine apparatus of dendritic spines. Proc Natl Acad Sci U S A 2022; 119:e2203750119. [PMID: 36215465 PMCID: PMC9586327 DOI: 10.1073/pnas.2203750119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 09/02/2022] [Indexed: 02/03/2023] Open
Abstract
The spine apparatus is a specialized compartment of the neuronal smooth endoplasmic reticulum (ER) located in a subset of dendritic spines. It consists of stacks of ER cisterns that are interconnected by an unknown dense matrix and are continuous with each other and with the ER of the dendritic shaft. While this organelle was first observed over 60 y ago, its molecular organization remains a mystery. Here, we performed in vivo proximity proteomics to gain some insight into its molecular components. To do so, we used the only known spine apparatus-specific protein, synaptopodin, to target a biotinylating enzyme to this organelle. We validated the specific localization in dendritic spines of a small subset of proteins identified by this approach, and we further showed their colocalization with synaptopodin when expressed in nonneuronal cells. One such protein is Pdlim7, an actin binding protein not previously identified in spines. Pdlim7, which we found to interact with synaptopodin through multiple domains, also colocalizes with synaptopodin on the cisternal organelle, a peculiar stack of ER cisterns resembling the spine apparatus and found at axon initial segments of a subset of neurons. Moreover, Pdlim7 has an expression pattern similar to that of synaptopodin in the brain, highlighting a functional partnership between the two proteins. The components of the spine apparatus identified in this work will help elucidate mechanisms in the biogenesis and maintenance of this enigmatic structure with implications for the function of dendritic spines in physiology and disease.
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Affiliation(s)
- Hanieh Falahati
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510
- HHMI, Yale University School of Medicine, New Haven, CT 06510
- Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University School of Medicine, New Haven, CT 06510
| | - Yumei Wu
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510
- HHMI, Yale University School of Medicine, New Haven, CT 06510
- Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University School of Medicine, New Haven, CT 06510
| | - Vanessa Feuerer
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510
- HHMI, Yale University School of Medicine, New Haven, CT 06510
- Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University School of Medicine, New Haven, CT 06510
| | - Hans-Georg Simon
- Department of Pediatrics, Feinberg School of Medicine, Northwestern University and Stanley Manne Children’s Research Institute, Chicago, IL 60611
| | - Pietro De Camilli
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06510
- Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510
- HHMI, Yale University School of Medicine, New Haven, CT 06510
- Program in Cellular Neuroscience, Neurodegeneration, and Repair, Yale University School of Medicine, New Haven, CT 06510
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9
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Paul MH, Choi M, Schlaudraff J, Deller T, Del Turco D. Granule Cell Ensembles in Mouse Dentate Gyrus Rapidly Upregulate the Plasticity-Related Protein Synaptopodin after Exploration Behavior. Cereb Cortex 2021; 30:2185-2198. [PMID: 31812981 PMCID: PMC7175005 DOI: 10.1093/cercor/bhz231] [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] [Indexed: 01/07/2023] Open
Abstract
The plasticity-related protein Synaptopodin (SP) has been implicated in neuronal plasticity. SP is targeted to dendritic spines and the axon initial segment, where it organizes the endoplasmic reticulum (ER) into the spine apparatus and the cisternal organelle, respectively. Here, we report an inducible third localization of SP in the somata of activated granule cell ensembles in mouse dentate gyrus. Using immunofluorescence and fluorescence in situ hybridization, we observed a subpopulation of mature granule cells (~1–2%) exhibiting perinuclear SP protein and a strong somatic SP mRNA signal. Double immunofluorescence labeling for Arc demonstrated that ~ 75% of these somatic SP-positive cells are also Arc-positive. Placement of mice into a novel environment caused a rapid (~2–4 h) induction of Arc, SP mRNA, and SP protein in exploration-induced granule cell ensembles. Lesion experiments showed that this induction requires input from the entorhinal cortex. Somatic SP colocalized with α-Actinin2, a known binding partner of SP. Finally, ultrastructural analysis revealed SP immunoprecipitate on dense plates linking cytoplasmic and perinuclear ER cisterns; these structures were absent in granule cells of SP-deficient mice. Our data implicate SP in the formation of contextual representations in the dentate gyrus and the behaviorally induced reorganization of cytoplasmic and perinuclear ER.
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Affiliation(s)
- Mandy H Paul
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, D-60590 Frankfurt/Main, Germany
| | - Myoung Choi
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, D-60590 Frankfurt/Main, Germany
| | - Jessica Schlaudraff
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, D-60590 Frankfurt/Main, Germany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, D-60590 Frankfurt/Main, Germany
| | - Domenico Del Turco
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, D-60590 Frankfurt/Main, Germany
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10
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Epigenomically Bistable Regions across Neuron-Specific Genes Govern Neuron Eligibility to a Coding Ensemble in the Hippocampus. Cell Rep 2021; 31:107789. [PMID: 32579919 PMCID: PMC7440841 DOI: 10.1016/j.celrep.2020.107789] [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: 01/27/2020] [Revised: 04/12/2020] [Accepted: 05/29/2020] [Indexed: 12/20/2022] Open
Abstract
Sensory inputs activate sparse neuronal ensembles in the dentate gyrus of the hippocampus, but how eligibility of individual neurons to recruitment is determined remains elusive. We identify thousands of largely bistable (CpG methylated or unmethylated) regions within neuronal gene bodies, established during mouse dentate gyrus development. Reducing DNA methylation and the proportion of the methylated epialleles at bistable regions compromises novel context-induced neuronal activation. Conversely, increasing methylation and the frequency of the methylated epialleles at bistable regions enhances intrinsic excitability. Single-nucleus profiling reveals enrichment of specific epialleles related to a subset of primarily exonic, bistable regions in activated neurons. Genes displaying both differential methylation and expression in activated neurons define a network of proteins regulating neuronal excitability and structural plasticity. We propose a model in which bistable regions create neuron heterogeneity and constellations of exonic methylation, which may contribute to cell-specific gene expression, excitability, and eligibility to a coding ensemble. Odell et al. show regions within neuronal genes with bistable DNA methylation states that are associated with gene expression, excitability, and activation in the dentate gyrus of the hippocampus. These data suggest that the methylation state of bistable regions dictates, via modulating gene expression, neuron eligibility to a coding ensemble.
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11
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Yap K, Drakew A, Smilovic D, Rietsche M, Paul MH, Vuksic M, Del Turco D, Deller T. The actin-modulating protein synaptopodin mediates long-term survival of dendritic spines. eLife 2020; 9:e62944. [PMID: 33275099 PMCID: PMC7717903 DOI: 10.7554/elife.62944] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 11/14/2020] [Indexed: 12/15/2022] Open
Abstract
Large spines are stable and important for memory trace formation. The majority of large spines also contains synaptopodin (SP), an actin-modulating and plasticity-related protein. Since SP stabilizes F-actin, we speculated that the presence of SP within large spines could explain their long lifetime. Indeed, using 2-photon time-lapse imaging of SP-transgenic granule cells in mouse organotypic tissue cultures we found that spines containing SP survived considerably longer than spines of equal size without SP. Of note, SP-positive (SP+) spines that underwent pruning first lost SP before disappearing. Whereas the survival time courses of SP+ spines followed conditional two-stage decay functions, SP-negative (SP-) spines and all spines of SP-deficient animals showed single-phase exponential decays. This was also the case following afferent denervation. These results implicate SP as a major regulator of long-term spine stability: SP clusters stabilize spines, and the presence of SP indicates spines of high stability.
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Affiliation(s)
- Kenrick Yap
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
| | - Alexander Drakew
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
| | - Dinko Smilovic
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
- Croatian Institute for Brain Research, School of Medicine, University of ZagrebZagrebCroatia
| | - Michael Rietsche
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
| | - Mandy H Paul
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
| | - Mario Vuksic
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
- Croatian Institute for Brain Research, School of Medicine, University of ZagrebZagrebCroatia
| | - Domenico Del Turco
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe University FrankfurtFrankfurtGermany
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12
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Wang RX, Lee JS, Campbell EL, Colgan SP. Microbiota-derived butyrate dynamically regulates intestinal homeostasis through regulation of actin-associated protein synaptopodin. Proc Natl Acad Sci U S A 2020; 117:11648-11657. [PMID: 32398370 PMCID: PMC7260972 DOI: 10.1073/pnas.1917597117] [Citation(s) in RCA: 159] [Impact Index Per Article: 39.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The intestinal mucosa exists in dynamic balance with trillions of luminal microbes. Disruption of the intestinal epithelial barrier, commonly observed in mucosal inflammation and diseases such as inflammatory bowel diseases (IBDs), is often associated with dysbiosis, particularly decreases in species producing short-chain fatty acids (SCFAs), such as butyrate. It remains unclear to what extent microbiota-derived factors contribute to the overall maintenance of intestinal homeostasis. Initial studies revealed that butyrate selectively promotes epithelial barrier function and wound healing. We aimed to define the specific mechanism(s) through which butyrate contributes to these epithelial responses. Guided by an unbiased profiling approach, we identified the dominant regulation of the actin-binding protein synaptopodin (SYNPO). Extensions of this work revealed a role for SYNPO in intestinal epithelial barrier function and wound healing. SYNPO was localized to the intestinal epithelial tight junction and within F-actin stress fibers where it is critical for barrier integrity and cell motility. Butyrate, but not other SCFAs, induced SYNPO in epithelial cell lines and murine colonic enteroids through mechanisms possibly involving histone deacetylase inhibition. Moreover, depletion of the microbiota abrogated expression of SYNPO in the mouse colon, which was rescued with butyrate repletion. Studies in Synpo-deficient mice demonstrated exacerbated disease susceptibility and increased intestinal permeability in a dextran sulfate sodium colitis model. These findings establish a critical role for the microbiota and their products, specifically butyrate, in the regulated expression of SYNPO for intestinal homeostasis and reveal a direct mechanistic link between microbiota-derived butyrate and barrier restoration.
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Affiliation(s)
- Ruth X Wang
- Mucosal Inflammation Program, Department of Medicine, University of Colorado School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
- Medical Scientist Training Program, University of Colorado School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - J Scott Lee
- Mucosal Inflammation Program, Department of Medicine, University of Colorado School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045
| | - Eric L Campbell
- Centre for Experimental Medicine, Queens University Belfast, Belfast BT9 7BL, Northern Ireland
| | - Sean P Colgan
- Mucosal Inflammation Program, Department of Medicine, University of Colorado School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO 80045;
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13
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Kassab S, Begley P, Church SJ, Rotariu SM, Chevalier-Riffard C, Dowsey AW, Phillips AM, Zeef LAH, Grayson B, Neill JC, Cooper GJS, Unwin RD, Gardiner NJ. Cognitive dysfunction in diabetic rats is prevented by pyridoxamine treatment. A multidisciplinary investigation. Mol Metab 2019; 28:107-119. [PMID: 31451429 PMCID: PMC6822151 DOI: 10.1016/j.molmet.2019.08.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Revised: 07/24/2019] [Accepted: 08/01/2019] [Indexed: 01/21/2023] Open
Abstract
OBJECTIVE The impact of diabetes mellitus on the central nervous system is less widely studied than in the peripheral nervous system, but there is increasing evidence that it elevates the risk of developing cognitive deficits. The aim of this study was to characterize the impact of experimental diabetes on the proteome and metabolome of the hippocampus. We tested the hypothesis that the vitamin B6 isoform pyridoxamine is protective against functional and molecular changes in diabetes. METHODS We tested recognition memory using the novel object recognition (NOR) test in streptozotocin (STZ)-induced diabetic, age-matched control, and pyridoxamine- or insulin-treated diabetic male Wistar rats. Comprehensive untargeted metabolomic and proteomic analyses, using gas chromatography-mass spectrometry and iTRAQ-enabled protein quantitation respectively, were utilized to characterize the molecular changes in the hippocampus in diabetes. RESULTS We demonstrated diabetes-specific, long-term (but not short-term) recognition memory impairment and that this deficit was prevented by insulin or pyridoxamine treatment. Metabolomic analysis showed diabetes-associated changes in 13/82 identified metabolites including polyol pathway intermediates glucose (9.2-fold), fructose (4.9-fold) and sorbitol (5.2-fold). We identified and quantified 4807 hippocampal proteins; 806 were significantly altered in diabetes. Pathway analysis revealed significant alterations in cytoskeletal components associated with synaptic plasticity, glutamatergic signaling, oxidative stress, DNA damage and FXR/RXR activation pathways in the diabetic rat hippocampus. CONCLUSIONS Our data indicate a protective effect of pyridoxamine against diabetes-induced cognitive deficits, and our comprehensive 'omics datasets provide insight into the pathogenesis of cognitive dysfunction enabling development of further mechanistic and therapeutic studies.
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Affiliation(s)
- Sarah Kassab
- Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Paul Begley
- Faculty of Biology, Medicine and Health, University of Manchester, UK
| | | | | | | | - Andrew W Dowsey
- Department of Population Health Sciences and Bristol Veterinary School, Faculty of Health Sciences, University of Bristol, Bristol, BS8 2BN, UK
| | - Alexander M Phillips
- Department of Electrical Engineering and Electronics, University of Liverpool, UK
| | - Leo A H Zeef
- Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Ben Grayson
- Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Joanna C Neill
- Faculty of Biology, Medicine and Health, University of Manchester, UK
| | - Garth J S Cooper
- Faculty of Biology, Medicine and Health, University of Manchester, UK; School of Biological Sciences, University of Auckland, New Zealand
| | - Richard D Unwin
- Faculty of Biology, Medicine and Health, University of Manchester, UK
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14
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Konietzny A, González-Gallego J, Bär J, Perez-Alvarez A, Drakew A, Demmers JAA, Dekkers DHW, Hammer JA, Frotscher M, Oertner TG, Wagner W, Kneussel M, Mikhaylova M. Myosin V regulates synaptopodin clustering and localization in the dendrites of hippocampal neurons. J Cell Sci 2019; 132:jcs.230177. [PMID: 31371487 PMCID: PMC6737913 DOI: 10.1242/jcs.230177] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 07/19/2019] [Indexed: 01/15/2023] Open
Abstract
The spine apparatus (SA) is an endoplasmic reticulum-related organelle that is present in a subset of dendritic spines in cortical and pyramidal neurons, and plays an important role in Ca2+ homeostasis and dendritic spine plasticity. The protein synaptopodin is essential for the formation of the SA and is widely used as a maker for this organelle. However, it is still unclear which factors contribute to its localization at selected synapses, and how it triggers local SA formation. In this study, we characterized development, localization and mobility of synaptopodin clusters in hippocampal primary neurons, as well as the molecular dynamics within these clusters. Interestingly, synaptopodin at the shaft-associated clusters is less dynamic than at spinous clusters. We identify the actin-based motor proteins myosin V (herein referring to both the myosin Va and Vb forms) and VI as novel interaction partners of synaptopodin, and demonstrate that myosin V is important for the formation and/or maintenance of the SA. We found no evidence of active microtubule-based transport of synaptopodin. Instead, new clusters emerge inside spines, which we interpret as the SA being assembled on-site.
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Affiliation(s)
- Anja Konietzny
- DFG Emmy Noether Group 'Neuronal Protein Transport', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Judit González-Gallego
- DFG Emmy Noether Group 'Neuronal Protein Transport', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Julia Bär
- DFG Emmy Noether Group 'Neuronal Protein Transport', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Alberto Perez-Alvarez
- Institute for Synaptic Physiology, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Alexander Drakew
- Institute of Structural Neurobiology, Center for Molecular Neurobiology Hamburg, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany.,Institute of Clinical Neuroanatomy, Faculty of Medicine, Theodor-Stern-Kai 7, 60590 Frankfurt, Germany
| | | | - Dick H W Dekkers
- Center for Proteomics, Erasmus MC, 3000 CA Rotterdam, The Netherlands
| | - John A Hammer
- Cell Biology and Physiology Center, National Heart, Lung Blood Institute, National Institutes of Health, Bethesda, MD 20814, USA
| | - Michael Frotscher
- Institute of Structural Neurobiology, Center for Molecular Neurobiology Hamburg, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Thomas G Oertner
- Institute for Synaptic Physiology, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Wolfgang Wagner
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Matthias Kneussel
- Department of Molecular Neurogenetics, Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
| | - Marina Mikhaylova
- DFG Emmy Noether Group 'Neuronal Protein Transport', Center for Molecular Neurobiology, ZMNH, University Medical Center Hamburg-Eppendorf, 20251 Hamburg, Germany
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15
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Yang Y, Hao H, Wu X, Guo S, Liu Y, Ran J, Li T, Li D, Liu M, Zhou J. Mixed-lineage leukemia protein 2 suppresses ciliary assembly by the modulation of actin dynamics and vesicle transport. Cell Discov 2019; 5:33. [PMID: 31263570 PMCID: PMC6591415 DOI: 10.1038/s41421-019-0100-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 04/18/2019] [Accepted: 04/22/2019] [Indexed: 01/27/2023] Open
Abstract
Primary cilia are critically involved in the coordination of diverse signaling pathways and ciliary defects are associated with a variety of human diseases. The past decades have witnessed great progress in the core machinery orchestrating ciliary assembly. However, the upstream epigenetic cues that direct ciliogenesis remain elusive. Herein, we demonstrate that mixed-lineage leukemia protein 2 (MLL2), a histone methyltransferase, plays a negative role in ciliogenesis. RNA-sequencing analysis reveals that the expression of five actin-associated proteins is significantly downregulated in MLL2-depleted cells. Overexpression of these proteins partially rescues ciliary abnormality elicited by MLL2 depletion. Our data also show that actin dynamics is remarkably changed in MLL2-depleted cells, resulting in the impairment of cell adhesion, spreading, and motility. In addition, MLL2 depletion promotes ciliary vesicle trafficking to the basal body in an actin-related manner. Together, these results reveal that MLL2 inhibits ciliogenesis by modulating actin dynamics and vesicle transport, and suggest that alteration of MLL2 may contribute to the pathogenesis of cilium-associated diseases.
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Affiliation(s)
- Yang Yang
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Huijie Hao
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Xiaofan Wu
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Song Guo
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Yang Liu
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Jie Ran
- 2Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, Shandong 250014 China
| | - Te Li
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Dengwen Li
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China
| | - Min Liu
- 2Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, Shandong 250014 China
| | - Jun Zhou
- 1State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials of the Ministry of Education, Tianjin Key Laboratory of Protein Science, College of Life Sciences, Nankai University, Tianjin, 300071 China.,2Shandong Provincial Key Laboratory of Animal Resistance Biology, Collaborative Innovation Center of Cell Biology in Universities of Shandong, Institute of Biomedical Sciences, College of Life Sciences, Shandong Normal University, Jinan, Shandong 250014 China
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16
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KIBRA Team Up with Partners to Promote Breast Cancer Metastasis. Pathol Oncol Res 2019; 26:627-634. [DOI: 10.1007/s12253-019-00660-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 04/01/2019] [Indexed: 02/06/2023]
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17
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Ji C, Tang M, Zeidler C, Höhfeld J, Johnson GV. BAG3 and SYNPO (synaptopodin) facilitate phospho-MAPT/Tau degradation via autophagy in neuronal processes. Autophagy 2019; 15:1199-1213. [PMID: 30744518 DOI: 10.1080/15548627.2019.1580096] [Citation(s) in RCA: 55] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
A major cellular catabolic pathway in neurons is macroautophagy/autophagy, through which misfolded or aggregation-prone proteins are sequestered into autophagosomes that fuse with lysosomes, and are degraded. MAPT (microtubule-associated protein tau) is one of the protein clients of autophagy. Given that accumulation of hyperphosphorylated MAPT contributes to the pathogenesis of Alzheimer disease and other tauopathies, decreasing endogenous MAPT levels has been shown to be beneficial to neuronal health in models of these diseases. A previous study demonstrated that the HSPA/HSP70 co-chaperone BAG3 (BCL2-associated athanogene 3) facilitates endogenous MAPT clearance through autophagy. These findings prompted us to further investigate the mechanisms underlying BAG3-mediated autophagy in the degradation of endogenous MAPT. Here we demonstrate for the first time that BAG3 plays an important role in autophagic flux in the neurites of mature neurons (20-24 days in vitro [DIV]) through interaction with the post-synaptic cytoskeleton protein SYNPO (synaptopodin). Loss of either BAG3 or SYNPO impeded the fusion of autophagosomes and lysosomes predominantly in the post-synaptic compartment. A block of autophagy leads to accumulation of the autophagic receptor protein SQSTM1/p62 (sequestosome 1) as well as MAPT phosphorylated at Ser262 (p-Ser262). Furthermore, p-Ser262 appears to accumulate in autophagosomes at post-synaptic densities. Overall these data provide evidence of a novel role for the co-chaperone BAG3 in synapses. In cooperation with SYNPO, it functions as part of a surveillance complex that facilitates the autophagic clearance of MAPT p-Ser262, and possibly other MAPT species at the post-synapse. This appears to be crucial for the maintenance of a healthy, functional synapse.Abbreviations: aa: amino acids; ACTB: actin beta; BafA1: bafilomycin A1; BAG3: BCL2 associated athanogene 3; CQ chloroquine; CTSL: cathepsin L; DIV: days in vitro; DLG4/PSD95: discs large MAGUK scaffold protein 4; HSPA/HSP70: heat shock protein family A (Hsp70); MAP1LC3B/LC3B: microtubule associated protein 1 light chain 3 beta; MAP2: microtubule associated protein 2; MAPT: microtubule associated protein tau; p-Ser262: MAPT phosphorylated at serine 262; p-Ser396/404: MAPT phosphorylated at serines 396 and 404; p-Thr231: MAPT phosphorylated at threonine 231; PBS: phosphate buffered saline; PK: proteinase K; scr: scrambled; shRNA: short hairpin RNA; SQSTM1/p62 sequestosome 1; SYN1: synapsin I; SYNPO synaptopodin; SYNPO2/myopodin: synaptopodin 2; VPS: vacuolar protein sorting.
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Affiliation(s)
- Changyi Ji
- a Department of Anesthesiology , University of Rochester , Rochester , NY , USA
| | - Maoping Tang
- a Department of Anesthesiology , University of Rochester , Rochester , NY , USA
| | - Claudia Zeidler
- b Institute for Cell Biology , University of Bonn , Bonn , Germany
| | - Jörg Höhfeld
- b Institute for Cell Biology , University of Bonn , Bonn , Germany
| | - Gail Vw Johnson
- a Department of Anesthesiology , University of Rochester , Rochester , NY , USA
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18
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Xiang R, McNally J, Bond J, Tucker D, Cameron M, Donaldson AJ, Austin KL, Rowe S, Jonker A, Pinares-Patino CS, McEwan JC, Vercoe PE, Oddy VH, Dalrymple BP. Across-Experiment Transcriptomics of Sheep Rumen Identifies Expression of Lipid/Oxo-Acid Metabolism and Muscle Cell Junction Genes Associated With Variation in Methane-Related Phenotypes. Front Genet 2018; 9:330. [PMID: 30177952 PMCID: PMC6109778 DOI: 10.3389/fgene.2018.00330] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2018] [Accepted: 07/31/2018] [Indexed: 01/03/2023] Open
Abstract
Ruminants are significant contributors to the livestock generated component of the greenhouse gas, methane (CH4). The CH4 is primarily produced by the rumen microbes. Although the composition of the diet and animal intake amount have the largest effect on CH4 production and yield (CH4 production/dry matter intake, DMI), the host also influences CH4 yield. Shorter rumen feed mean retention time (MRT) is associated with higher dry matter intake and lower CH4 yield, but the molecular mechanism(s) by which the host affects CH4 production remain unclear. We integrated rumen wall transcriptome data and CH4 phenotypes from two independent experiments conducted with sheep in Australia (AUS, n = 62) and New Zealand (NZ, n = 24). The inclusion of the AUS data validated the previously identified clusters and gene sets representing rumen epithelial, metabolic and muscular functions. In addition, the expression of the cell cycle genes as a group was consistently positively correlated with acetate and butyrate concentrations (p < 0.05, based on AUS and NZ data together). The expression of a group of metabolic genes showed positive correlations in both AUS and NZ datasets with CH4 production (p < 0.05) and yield (p < 0.01). These genes encode key enzymes in the ketone body synthesis pathway and included members of the poorly characterized aldo-keto reductase 1C (AKR1C) family. Several AKR1C family genes appear to have ruminant specific evolution patterns, supporting their specialized roles in the ruminants. Combining differential gene expression in the rumen wall muscle of the shortest and longest MRT AUS animals (no data available for the NZ animals) with correlation and network analysis, we identified a set of rumen muscle genes involved in cell junctions as potential regulators of MRT, presumably by influencing contraction rates of the smooth muscle component of the rumen wall. Higher rumen expression of these genes, including SYNPO (synaptopodin, p < 0.01) and NEXN (nexilin, p < 0.05), was associated with lower CH4 yield in both AUS and NZ datasets. Unlike the metabolic genes, the variations in the expression of which may reflect the availability of rumen metabolites, the muscle genes are currently our best candidates for causal genes that influence CH4 yield.
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Affiliation(s)
- Ruidong Xiang
- CSIRO Agriculture & Food, Queensland Bioscience Precinct, St Lucia, QLD, Australia.,Faculty of Veterinary and Agricultural Sciences, The University of Melbourne, Parkville, VIC, Australia.,Agriculture Victoria, AgriBio, Centre for AgriBioscience, Bundoora, VIC, Australia
| | - Jody McNally
- F. D. McMaster Laboratory, CSIRO Agriculture & Food, Armidale, NSW, Australia
| | - Jude Bond
- NSW Department of Primary Industries, Extensive Livestock Industries Centre, University of New England, Armidale, NSW, Australia
| | - David Tucker
- NSW Department of Primary Industries, Extensive Livestock Industries Centre, University of New England, Armidale, NSW, Australia
| | - Margaret Cameron
- NSW Department of Primary Industries, Extensive Livestock Industries Centre, University of New England, Armidale, NSW, Australia
| | - Alistair J Donaldson
- NSW Department of Primary Industries, Extensive Livestock Industries Centre, University of New England, Armidale, NSW, Australia
| | - Katie L Austin
- NSW Department of Primary Industries, Extensive Livestock Industries Centre, University of New England, Armidale, NSW, Australia
| | - Suzanne Rowe
- Invermay Agricultural Centre, AgResearch Limited, Mosgiel, New Zealand
| | - Arjan Jonker
- Grasslands Research Centre, AgResearch Limited, Palmerston North, New Zealand
| | - Cesar S Pinares-Patino
- Grasslands Research Centre, AgResearch Limited, Palmerston North, New Zealand.,New Zealand-Peru Dairy Support Project, MINAGRI, Lima, Peru
| | - John C McEwan
- Invermay Agricultural Centre, AgResearch Limited, Mosgiel, New Zealand
| | - Phil E Vercoe
- School of Animal Biology, The University of Western Australia, Crawley, WA, Australia.,Institute of Agriculture, The University of Western Australia, Crawley, WA, Australia
| | - V H Oddy
- NSW Department of Primary Industries, Extensive Livestock Industries Centre, University of New England, Armidale, NSW, Australia
| | - Brian P Dalrymple
- CSIRO Agriculture & Food, Queensland Bioscience Precinct, St Lucia, QLD, Australia.,Institute of Agriculture, The University of Western Australia, Crawley, WA, Australia
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19
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Kannan N, Tang VW. Myosin-1c promotes E-cadherin tension and force-dependent recruitment of α-actinin to the epithelial cell junction. J Cell Sci 2018; 131:jcs.211334. [PMID: 29748378 DOI: 10.1242/jcs.211334] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 05/02/2018] [Indexed: 12/26/2022] Open
Abstract
Actomyosin II contractility in epithelial cell plays an essential role in tension-dependent adhesion strengthening. One key unsettling question is how cellular contraction transmits force to the nascent cell-cell adhesion when there is no stable attachment between the nascent adhesion complex and actin filament. Here, we show that myosin-1c is localized to the lateral membrane of polarized epithelial cells and facilitates the coupling between actin and cell-cell adhesion. Knockdown of myosin-1c compromised the integrity of the lateral membrane, reduced the generation of tension at E-cadherin, decreased the strength of cell-cell cohesion in an epithelial cell monolayer and prevented force-dependent recruitment of junctional α-actinin. Application of exogenous force to cell-cell adhesions in a myosin-1c-knockdown cell monolayer fully rescued the localization defect of α-actinin, indicating that junction mechanoregulation remains intact in myosin-1c-depleted cells. Our study identifies a role of myosin-1c in force transmission at the lateral cell-cell interface and underscores a non-junctional contribution to tension-dependent junction regulation.
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Affiliation(s)
- Nivetha Kannan
- Department of Cell and Developmental Biology, University of Illinois, Urbana-Champaign, IL 61801 USA
| | - Vivian W Tang
- Department of Cell and Developmental Biology, University of Illinois, Urbana-Champaign, IL 61801 USA
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20
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Posner MG, Upadhyay A, Ishima R, Kalli AC, Harris G, Kremerskothen J, Sansom MSP, Crennell SJ, Bagby S. Distinctive phosphoinositide- and Ca 2+-binding properties of normal and cognitive performance-linked variant forms of KIBRA C2 domain. J Biol Chem 2018; 293:9335-9344. [PMID: 29724824 PMCID: PMC6005455 DOI: 10.1074/jbc.ra118.002279] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2018] [Revised: 05/03/2018] [Indexed: 01/07/2023] Open
Abstract
Kidney- and brain-expressed protein (KIBRA), a multifunctional scaffold protein with around 20 known binding partners, is involved in memory and cognition, organ size control via the Hippo pathway, cell polarity, and membrane trafficking. KIBRA includes tandem N-terminal WW domains, a C2 domain, and motifs for binding atypical PKC and PDZ domains. A naturally occurring human KIBRA variant involving residue changes at positions 734 (Met-to-Ile) and 735 (Ser-to-Ala) within the C2 domain affects cognitive performance. We have elucidated 3D structures and calcium- and phosphoinositide-binding properties of human KIBRA C2 domain. Both WT and variant C2 adopt a canonical type I topology C2 domain fold. Neither Ca2+ nor any other metal ion was bound to WT or variant KIBRA C2 in crystal structures, and Ca2+ titration produced no significant reproducible changes in NMR spectra. NMR and X-ray diffraction data indicate that KIBRA C2 binds phosphoinositides via an atypical site involving β-strands 5, 2, 1, and 8. Molecular dynamics simulations indicate that KIBRA C2 interacts with membranes via primary and secondary sites on the same domain face as the experimentally identified phosphoinositide-binding site. Our results indicate that KIBRA C2 domain association with membranes is calcium-independent and involves distinctive C2 domain-membrane relative orientations.
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Affiliation(s)
- Mareike G. Posner
- From the Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, United Kingdom
| | - Abhishek Upadhyay
- From the Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, United Kingdom
| | - Rieko Ishima
- Department of Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15260
| | - Antreas C. Kalli
- Leeds Institute of Cancer and Pathology, University of Leeds, Leeds LS9 7TF, United Kingdom, ,Astbury Centre for Structural Molecular Biology, University of Leeds, Leeds LS2 9JT, United Kingdom
| | - Gemma Harris
- Research Complex at Harwell, Rutherford Appleton Laboratory, Didcot OX11 0FA, United Kingdom
| | - Joachim Kremerskothen
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, D-48149 Münster, Germany, and
| | - Mark S. P. Sansom
- Department of Biochemistry, University of Oxford, Oxford OX1 3QU, United Kingdom
| | - Susan J. Crennell
- From the Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, United Kingdom
| | - Stefan Bagby
- From the Department of Biology and Biochemistry, University of Bath, Bath BA2 7AY, United Kingdom, , To whom correspondence should be addressed. Tel.:
44-1225-386436; Fax:
44-1225-386779; E-mail:
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21
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Barón-Mendoza I, García O, Calvo-Ochoa E, Rebollar-García JO, Garzón-Cortés D, Haro R, González-Arenas A. Alterations in neuronal cytoskeletal and astrocytic proteins content in the brain of the autistic-like mouse strain C58/J. Neurosci Lett 2018; 682:32-38. [PMID: 29885454 DOI: 10.1016/j.neulet.2018.06.004] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 06/01/2018] [Accepted: 06/05/2018] [Indexed: 12/22/2022]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopment disorder characterized by deficient social interaction, impaired communication as well as repetitive behaviors. ASD subjects present connectivity and neuroplasticity disturbances associated with morphological alterations in axons, dendrites, and dendritic spines. Given that the neuronal cytoskeleton and astrocytes have an essential role in regulating several mechanisms of neural plasticity, the aim of this work was to study alterations in the content of neuronal cytoskeletal components actin and tubulin and their associated proteins, as well as astrocytic proteins GFAP and TSP-1 in the brain of a C58/J mouse model of ASD. We determined the expression and regulatory phosphorylation state of cytoskeletal components in the prefrontal cortex, hippocampus, and cerebellum of C58/J mice by means of Western blotting. Our results show that autistic-like mice present: 1) region-dependent altered expression and phosphorylation patterns of Tau isoforms, associated with anomalous microtubule depolymerization; 2) reduced MAP2 A content in prefrontal cortex; 3) region-dependent changes in cofilin expression and phosphorylation, associated with abnormal actin filament depolymerizing dynamics; 4) diminished synaptopodin levels in the hippocampus; and 5) reduced content of the astrocyte-secreted protein TSP-1 in the prefrontal cortex and hippocampus. Our work demonstrates changes in the expression and phosphorylation of cytoskeletal proteins as well as in TSP-1 in the brain of the autistic-like mice C58/J, shedding light in one of the possible molecular mechanisms underpinning neuroplasticity alterations in the ASD brain and laying the foundation for future investigations in this topic.
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Affiliation(s)
- Isabel Barón-Mendoza
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Octavio García
- Departamento de Psicobiología y Neurociencias, Facultad de Psicología, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Erika Calvo-Ochoa
- Department of Biological Sciences, Western Michigan University, Kalamazoo, MI, USA
| | - Jorge Omar Rebollar-García
- Unidad de Modelos Biológicos, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Daniel Garzón-Cortés
- Unidad de Modelos Biológicos, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, México
| | - Reyes Haro
- Instituto Mexicano de Medicina Integral de Sueño, Ciudad de México, México
| | - Aliesha González-Arenas
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Ciudad de México, México.
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22
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Datta A, Chai YL, Tan JM, Lee JH, Francis PT, Chen CP, Sze SK, Lai MKP. An iTRAQ-based proteomic analysis reveals dysregulation of neocortical synaptopodin in Lewy body dementias. Mol Brain 2017; 10:36. [PMID: 28800743 PMCID: PMC5553757 DOI: 10.1186/s13041-017-0316-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 07/21/2017] [Indexed: 02/08/2023] Open
Abstract
Lewy body dementias are the second most common cause of neurodegenerative dementia in the elderly after Alzheimer's disease (AD). The two clinical subgroups of Lewy body dementias, namely, dementia with Lewy bodies (DLB) and Parkinson's disease dementia (PDD), are differentiated by the chronology of cognitive symptoms relative to parkinsonism. At present, there remains a debate on whether DLB and PDD are separate disease entities, or fall within the same spectrum of Lewy body dementias. In this study, we compared the detergent-soluble proteome via an 8-plex isobaric tag for relative and absolute quantitation (iTRAQ) analysis of pooled lysates from the prefrontal cortex (BA9) of DLB (n = 19) and PDD (n = 21) patients matched a priori for amyloid (total Aβ42) burden, semi-quantitative scores for Lewy bodies and neurofibrillary tangles together with age-matched control (n = 21) subjects. A total of 1914 proteins were confidently identified by iTRAQ (false discovery rate = 0%). None of the proteins showed a significant yet opposite regulation in between DLB and PDD when compared to aged controls in the proteomic data set as well as following immunoblot analysis of the pooled and individual lysates involving all 61 subjects. The postsynaptic protein, synaptopodin (SYNPO) was significantly down-regulated in both DLB and PDD subgroups, suggesting a defective synaptic transmission in the demented patients. In conclusion, the largely similar proteome of DLB and PDD matched for amyloid burden suggests that variations in concomitant AD-related pathology, abnormal post-translational modifications or protein-protein interactions, defective intracellular trafficking or misfolding of proteins could play a part in driving the clinically observed differences between these two subgroups of Lewy body dementias. This further indicates that amyloid-targeting therapeutic strategies may show different efficacies in DLB versus PDD.
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Affiliation(s)
- Arnab Datta
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, Singapore 117599, Singapore. .,Epithelial Systems Biology Laboratory, National Heart, Lung, and Blood Institute, Building 10 Room 6N318, Bethesda, MD 20814, USA.
| | - Yuek Ling Chai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, Singapore 117599, Singapore
| | - Jing Min Tan
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, Singapore 117599, Singapore
| | - Jasinda H Lee
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, Singapore 117599, Singapore
| | - Paul T Francis
- Wolfson Centre for Age-related Diseases, King's College London, Guy's Campus, St Thomas Street, London SE1 1UL, UK
| | - Christopher P Chen
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, Singapore 117599, Singapore
| | - Siu Kwan Sze
- School of Biological Sciences, Nanyang Technological University, Singapore 637551, Singapore
| | - Mitchell K P Lai
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, Unit 09-01, Centre for Translational Medicine (MD6), 14 Medical Drive, Kent Ridge, Singapore 117599, Singapore. .,Wolfson Centre for Age-related Diseases, King's College London, Guy's Campus, St Thomas Street, London SE1 1UL, UK.
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23
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Bryan K, McGivney BA, Farries G, McGettigan PA, McGivney CL, Gough KF, MacHugh DE, Katz LM, Hill EW. Equine skeletal muscle adaptations to exercise and training: evidence of differential regulation of autophagosomal and mitochondrial components. BMC Genomics 2017; 18:595. [PMID: 28793853 PMCID: PMC5551008 DOI: 10.1186/s12864-017-4007-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2017] [Accepted: 08/02/2017] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND A single bout of exercise induces changes in gene expression in skeletal muscle. Regular exercise results in an adaptive response involving changes in muscle architecture and biochemistry, and is an effective way to manage and prevent common human diseases such as obesity, cardiovascular disorders and type II diabetes. However, the biomolecular mechanisms underlying such responses still need to be fully elucidated. Here we performed a transcriptome-wide analysis of skeletal muscle tissue in a large cohort of untrained Thoroughbred horses (n = 51) before and after a bout of high-intensity exercise and again after an extended period of training. We hypothesized that regular high-intensity exercise training primes the transcriptome for the demands of high-intensity exercise. RESULTS An extensive set of genes was observed to be significantly differentially regulated in response to a single bout of high-intensity exercise in the untrained cohort (3241 genes) and following multiple bouts of high-intensity exercise training over a six-month period (3405 genes). Approximately one-third of these genes (1025) and several biological processes related to energy metabolism were common to both the exercise and training responses. We then developed a novel network-based computational analysis pipeline to test the hypothesis that these transcriptional changes also influence the contextual molecular interactome and its dynamics in response to exercise and training. The contextual network analysis identified several important hub genes, including the autophagosomal-related gene GABARAPL1, and dynamic functional modules, including those enriched for mitochondrial respiratory chain complexes I and V, that were differentially regulated and had their putative interactions 're-wired' in the exercise and/or training responses. CONCLUSION Here we have generated for the first time, a comprehensive set of genes that are differentially expressed in Thoroughbred skeletal muscle in response to both exercise and training. These data indicate that consecutive bouts of high-intensity exercise result in a priming of the skeletal muscle transcriptome for the demands of the next exercise bout. Furthermore, this may also lead to an extensive 're-wiring' of the molecular interactome in both exercise and training and include key genes and functional modules related to autophagy and the mitochondrion.
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Affiliation(s)
- Kenneth Bryan
- UCD School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Ireland
| | - Beatrice A. McGivney
- UCD School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Ireland
| | - Gabriella Farries
- UCD School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Ireland
| | - Paul A. McGettigan
- UCD School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Ireland
| | - Charlotte L. McGivney
- UCD School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Ireland
| | - Katie F. Gough
- UCD School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Ireland
| | - David E. MacHugh
- UCD School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Ireland
- UCD Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, D04 V1W8 Ireland
| | - Lisa M. Katz
- UCD School of Veterinary Medicine, University College Dublin, Belfield, D04 V1W8 Ireland
| | - Emmeline W. Hill
- UCD School of Agriculture and Food Science, University College Dublin, Belfield, D04 V1W8 Ireland
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24
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Kelly SC, He B, Perez SE, Ginsberg SD, Mufson EJ, Counts SE. Locus coeruleus cellular and molecular pathology during the progression of Alzheimer's disease. Acta Neuropathol Commun 2017; 5:8. [PMID: 28109312 PMCID: PMC5251221 DOI: 10.1186/s40478-017-0411-2] [Citation(s) in RCA: 186] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2017] [Accepted: 01/08/2017] [Indexed: 01/30/2023] Open
Abstract
A major feature of Alzheimer’s disease (AD) is the loss of noradrenergic locus coeruleus (LC) projection neurons that mediate attention, memory, and arousal. However, the extent to which the LC projection system degenerates during the initial stages of AD is still under investigation. To address this question, we performed tyrosine hydroxylase (TH) immunohistochemistry and unbiased stereology of noradrenergic LC neurons in tissue harvested postmortem from subjects who died with a clinical diagnosis of no cognitive impairment (NCI), amnestic mild cognitive impairment (aMCI, a putative prodromal AD stage), or mild/moderate AD. Stereologic estimates of total LC neuron number revealed a 30% loss during the transition from NCI to aMCI, with an additional 25% loss of LC neurons in AD. Decreases in noradrenergic LC neuron number were significantly associated with worsening antemortem global cognitive function as well as poorer performance on neuropsychological tests of episodic memory, semantic memory, working memory, perceptual speed, and visuospatial ability. Reduced LC neuron numbers were also associated with increased postmortem neuropathology. To examine the cellular and molecular pathogenic processes underlying LC neurodegeneration in aMCI, we performed single population microarray analysis. These studies revealed significant reductions in select functional classes of mRNAs regulating mitochondrial respiration, redox homeostasis, and neuritic structural plasticity in neurons accessed from both aMCI and AD subjects compared to NCI. Specific gene expression levels within these functional classes were also associated with global cognitive deterioration and neuropathological burden. Taken together, these observations suggest that noradrenergic LC cellular and molecular pathology is a prominent feature of prodromal disease that contributes to cognitive dysfunction. Moreover, they lend support to a rational basis for targeting LC neuroprotection as a disease modifying strategy.
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25
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Jedlicka P, Deller T. Understanding the role of synaptopodin and the spine apparatus in Hebbian synaptic plasticity - New perspectives and the need for computational modeling. Neurobiol Learn Mem 2016; 138:21-30. [PMID: 27470091 DOI: 10.1016/j.nlm.2016.07.023] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 07/15/2016] [Accepted: 07/23/2016] [Indexed: 12/17/2022]
Abstract
Synaptopodin (SP) is a proline-rich actin-associated protein essential for the formation of a spine apparatus (SA) in dendritic spines. The SA consists of stacks of smooth endoplasmic reticulum (sER) contiguous with the meshwork of somatodendritic ER. Spines of SP-deficient mice contain sER but no SA, demonstrating that SP is necessary for the assembly of ER cisterns into the more complex SA organelle. Although the SA was described decades ago, its function was difficult to investigate and remained elusive, in part because reliable markers for the SA were missing. After SP was identified as an essential component and a reliable marker of the SA, a role of SP/SA in hippocampal synaptic plasticity could be firmly established using loss-of-function approaches. Further studies revealed that SP/SA participate in the regulation of Ca2+-dependent spine-specific Hebbian plasticity and in activity-dependent changes in the spine actin cytoskeleton. In this review we are summarizing recent progress made on SP/SA in Hebbian plasticity and discuss open questions such as causality, spatiotemporal dynamics and complementarity of SP/SA-dependent mechanisms. We are proposing that computational modeling of spine Ca2+-signaling and actin remodeling pathways could address some of these issues and could indicate future research directions. Moreover, reaction-diffusion simulations could help to identify key feedforward and feedback regulatory motifs regulating the switch between an LTP and an LTD signaling module in SP/SA-containing spines, thus helping to find a unified view of SP/SA action in Hebbian plasticity.
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Affiliation(s)
- Peter Jedlicka
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, D-60590 Frankfurt/Main, Germany.
| | - Thomas Deller
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe University Frankfurt, D-60590 Frankfurt/Main, Germany.
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26
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Verbich D, Becker D, Vlachos A, Mundel P, Deller T, McKinney RA. Rewiring neuronal microcircuits of the brain via spine head protrusions--a role for synaptopodin and intracellular calcium stores. Acta Neuropathol Commun 2016; 4:38. [PMID: 27102112 PMCID: PMC4840984 DOI: 10.1186/s40478-016-0311-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 04/09/2016] [Indexed: 11/26/2022] Open
Abstract
Neurological diseases associated with neuronal death are also accompanied by axonal denervation of connected brain regions. In these areas, denervation leads to a decrease in afferent drive, which may in turn trigger active central nervous system (CNS) circuitry rearrangement. This rewiring process is important therapeutically, since it can partially recover functions and can be further enhanced using modern rehabilitation strategies. Nevertheless, the cellular mechanisms of brain rewiring are not fully understood. We recently reported a mechanism by which neurons remodel their local connectivity under conditions of network-perturbance: hippocampal pyramidal cells can extend spine head protrusions (SHPs), which reach out toward neighboring terminals and form new synapses. Since this form of activity-dependent rewiring is observed only on some spines, we investigated the required conditions. We speculated, that the actin-associated protein synaptopodin, which is involved in several synaptic plasticity mechanisms, could play a role in the formation and/or stabilization of SHPs. Using hippocampal slice cultures, we found that ~70 % of spines with protrusions in CA1 pyramidal neurons contained synaptopodin. Analysis of synaptopodin-deficient neurons revealed that synaptopodin is required for the stability but not the formation of SHPs. The effects of synaptopodin could be linked to its role in Ca2+ homeostasis, since spines with protrusions often contained ryanodine receptors and synaptopodin. Furthermore, disrupting Ca2+ signaling shortened protrusion lifetime. By transgenically reintroducing synaptopodin on a synaptopodin-deficient background, SHP stability could be rescued. Overall, we show that synaptopodin increases the stability of SHPs, and could potentially modulate the rewiring of microcircuitries by making synaptic reorganization more efficient.
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27
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Tracy TE, Sohn PD, Minami SS, Wang C, Min SW, Li Y, Zhou Y, Le D, Lo I, Ponnusamy R, Cong X, Schilling B, Ellerby LM, Huganir RL, Gan L. Acetylated Tau Obstructs KIBRA-Mediated Signaling in Synaptic Plasticity and Promotes Tauopathy-Related Memory Loss. Neuron 2016; 90:245-60. [PMID: 27041503 DOI: 10.1016/j.neuron.2016.03.005] [Citation(s) in RCA: 176] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2015] [Revised: 01/17/2016] [Accepted: 02/22/2016] [Indexed: 11/27/2022]
Abstract
Tau toxicity has been implicated in the emergence of synaptic dysfunction in Alzheimer's disease (AD), but the mechanism by which tau alters synapse physiology and leads to cognitive decline is unclear. Here we report abnormal acetylation of K274 and K281 on tau, identified in AD brains, promotes memory loss and disrupts synaptic plasticity by reducing postsynaptic KIdney/BRAin (KIBRA) protein, a memory-associated protein. Transgenic mice expressing human tau with lysine-to-glutamine mutations to mimic K274 and K281 acetylation (tauKQ) exhibit AD-related memory deficits and impaired hippocampal long-term potentiation (LTP). TauKQ reduces synaptic KIBRA levels and disrupts activity-induced postsynaptic actin remodeling and AMPA receptor insertion. The LTP deficit was rescued by promoting actin polymerization or by KIBRA expression. In AD patients with dementia, we found enhanced tau acetylation is linked to loss of KIBRA. These findings suggest a novel mechanism by which pathogenic tau causes synaptic dysfunction and cognitive decline in AD pathogenesis.
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Affiliation(s)
- Tara E Tracy
- Gladstone Institute of Neurological Disease, San Francisco, CA 91458, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 91458, USA
| | - Peter Dongmin Sohn
- Gladstone Institute of Neurological Disease, San Francisco, CA 91458, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 91458, USA
| | - S Sakura Minami
- Gladstone Institute of Neurological Disease, San Francisco, CA 91458, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 91458, USA
| | - Chao Wang
- Gladstone Institute of Neurological Disease, San Francisco, CA 91458, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 91458, USA
| | - Sang-Won Min
- Gladstone Institute of Neurological Disease, San Francisco, CA 91458, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 91458, USA
| | - Yaqiao Li
- Gladstone Institute of Neurological Disease, San Francisco, CA 91458, USA
| | - Yungui Zhou
- Gladstone Institute of Neurological Disease, San Francisco, CA 91458, USA
| | - David Le
- Gladstone Institute of Neurological Disease, San Francisco, CA 91458, USA
| | - Iris Lo
- Gladstone Institute of Neurological Disease, San Francisco, CA 91458, USA
| | | | - Xin Cong
- Buck Institute for Research on Aging, Novato, CA 94945, USA
| | | | - Lisa M Ellerby
- Buck Institute for Research on Aging, Novato, CA 94945, USA
| | - Richard L Huganir
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Li Gan
- Gladstone Institute of Neurological Disease, San Francisco, CA 91458, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA 91458, USA; Neuroscience Graduate Program, University of California, San Francisco, San Francisco, CA 91458, USA.
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28
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Kannan N, Tang VW. Synaptopodin couples epithelial contractility to α-actinin-4-dependent junction maturation. J Cell Biol 2016; 211:407-34. [PMID: 26504173 PMCID: PMC4621826 DOI: 10.1083/jcb.201412003] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
A novel tension-sensitive junctional protein, synaptopodin, can relay biophysical input from cellular actomyosin contractility to induce biochemical changes at cell–cell contacts, resulting in structural reorganization of the junctional complex and epithelial barrier maturation. The epithelial junction experiences mechanical force exerted by endogenous actomyosin activities and from interactions with neighboring cells. We hypothesize that tension generated at cell–cell adhesive contacts contributes to the maturation and assembly of the junctional complex. To test our hypothesis, we used a hydraulic apparatus that can apply mechanical force to intercellular junction in a confluent monolayer of cells. We found that mechanical force induces α-actinin-4 and actin accumulation at the cell junction in a time- and tension-dependent manner during junction development. Intercellular tension also induces α-actinin-4–dependent recruitment of vinculin to the cell junction. In addition, we have identified a tension-sensitive upstream regulator of α-actinin-4 as synaptopodin. Synaptopodin forms a complex containing α-actinin-4 and β-catenin and interacts with myosin II, indicating that it can physically link adhesion molecules to the cellular contractile apparatus. Synaptopodin depletion prevents junctional accumulation of α-actinin-4, vinculin, and actin. Knockdown of synaptopodin and α-actinin-4 decreases the strength of cell–cell adhesion, reduces the monolayer permeability barrier, and compromises cellular contractility. Our findings underscore the complexity of junction development and implicate a control process via tension-induced sequential incorporation of junctional components.
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Affiliation(s)
- Nivetha Kannan
- Program in Global Public Health, University of Illinois, Urbana-Champaign, Champaign, IL 61801
| | - Vivian W Tang
- Department of Cell and Developmental Biology, University of Illinois, Urbana-Champaign, Champaign, IL 61801
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Kalinowska M, Chávez AE, Lutzu S, Castillo PE, Bukauskas FF, Francesconi A. Actinin-4 Governs Dendritic Spine Dynamics and Promotes Their Remodeling by Metabotropic Glutamate Receptors. J Biol Chem 2015; 290:15909-20. [PMID: 25944910 DOI: 10.1074/jbc.m115.640136] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Indexed: 11/06/2022] Open
Abstract
Dendritic spines are dynamic, actin-rich protrusions in neurons that undergo remodeling during neuronal development and activity-dependent plasticity within the central nervous system. Although group 1 metabotropic glutamate receptors (mGluRs) are critical for spine remodeling under physiopathological conditions, the molecular components linking receptor activity to structural plasticity remain unknown. Here we identify a Ca(2+)-sensitive actin-binding protein, α-actinin-4, as a novel group 1 mGluR-interacting partner that orchestrates spine dynamics and morphogenesis in primary neurons. Functional silencing of α-actinin-4 abolished spine elongation and turnover stimulated by group 1 mGluRs despite intact surface receptor expression and downstream ERK1/2 signaling. This function of α-actinin-4 in spine dynamics was underscored by gain-of-function phenotypes in untreated neurons. Here α-actinin-4 induced spine head enlargement, a morphological change requiring the C-terminal domain of α-actinin-4 that binds to CaMKII, an interaction we showed to be regulated by group 1 mGluR activation. Our data provide mechanistic insights into spine remodeling by metabotropic signaling and identify α-actinin-4 as a critical effector of structural plasticity within neurons.
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Affiliation(s)
- Magdalena Kalinowska
- From the Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Andrés E Chávez
- From the Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Stefano Lutzu
- From the Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Pablo E Castillo
- From the Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Feliksas F Bukauskas
- From the Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
| | - Anna Francesconi
- From the Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York 10461
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Blanque A, Repetto D, Rohlmann A, Brockhaus J, Duning K, Pavenstädt H, Wolff I, Missler M. Deletion of KIBRA, protein expressed in kidney and brain, increases filopodial-like long dendritic spines in neocortical and hippocampal neurons in vivo and in vitro. Front Neuroanat 2015; 9:13. [PMID: 25750616 PMCID: PMC4335192 DOI: 10.3389/fnana.2015.00013] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2014] [Accepted: 01/31/2015] [Indexed: 11/28/2022] Open
Abstract
Spines are small protrusions arising from dendrites that receive most excitatory synaptic input in the brain. Dendritic spines represent dynamic structures that undergo activity-dependent adaptations, for example, during synaptic plasticity. Alterations of spine morphology, changes of spine type ratios or density have consequently been found in paradigms of learning and memory, and accompany many neuropsychiatric disorders. Polymorphisms in the gene encoding KIBRA, a protein present in kidney and brain, are linked to memory performance and cognition in humans and mouse models. Deletion of KIBRA impairs long-term synaptic plasticity and postsynaptic receptor recycling but no information is available on the morphology of dendritic spines in null-mutant mice. Here, we directly examine the role of KIBRA in spinous synapses using knockout mice. Since KIBRA is normally highly expressed in neocortex and hippocampus at juvenile age, we analyze synapse morphology in intact tissue and in neuronal cultures from these brain regions. Quantification of different dendritic spine types in Golgi-impregnated sections and in transfected neurons coherently reveal a robust increase of filopodial-like long protrusions in the absence of KIBRA. While distribution of pre- and postsynaptic marker proteins, overall synapse ultrastructure and density of asymmetric contacts were remarkably normal, electron microscopy additionally uncovered less perforated synapses and spinules in knockout neurons. Thus, our results indicate that KIBRA is involved in the maintenance of normal ratios of spinous synapses, and may thus provide a structural correlate of altered cognitive functions when this memory-associated molecule is mutated.
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Affiliation(s)
- Anja Blanque
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University Münster, Germany
| | - Daniele Repetto
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University Münster, Germany
| | - Astrid Rohlmann
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University Münster, Germany
| | - Johannes Brockhaus
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University Münster, Germany
| | - Kerstin Duning
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster Münster, Germany
| | - Hermann Pavenstädt
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster Münster, Germany
| | - Ilka Wolff
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University Münster, Germany
| | - Markus Missler
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University Münster, Germany ; Cluster of Excellence EXC 1003, Cells in Motion, CiM Münster, Germany
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31
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Abstract
α-Actinins are a major class of actin filament cross-linking proteins expressed in virtually all cells. In muscle, actinins cross-link thin filaments from adjacent sarcomeres. In non-muscle cells, different actinin isoforms play analogous roles in cross-linking actin filaments and anchoring them to structures such as cell-cell and cell-matrix junctions. Although actinins have long been known to play roles in cytokinesis, cell adhesion and cell migration, recent studies have provided further mechanistic insights into these functions. Roles for actinins in synaptic plasticity and membrane trafficking events have emerged more recently, as has a 'non-canonical' function for actinins in transcriptional regulation in the nucleus. In the present paper we review recent advances in our understanding of these diverse cell biological functions of actinins in non-muscle cells, as well as their roles in cancer and in genetic disorders affecting platelet and kidney physiology. We also make two proposals with regard to the actinin nomenclature. First, we argue that naming actinin isoforms according to their expression patterns is problematic and we suggest a more precise nomenclature system. Secondly, we suggest that the α in α-actinin is superfluous and can be omitted.
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Mun GI, Park S, Kremerskothen J, Boo YC. Expression of synaptopodin in endothelial cells exposed to laminar shear stress and its role in endothelial wound healing. FEBS Lett 2014; 588:1024-30. [DOI: 10.1016/j.febslet.2014.02.012] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 02/01/2014] [Accepted: 02/10/2014] [Indexed: 10/25/2022]
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Synaptic gene dysregulation within hippocampal CA1 pyramidal neurons in mild cognitive impairment. Neuropharmacology 2013; 79:172-9. [PMID: 24445080 DOI: 10.1016/j.neuropharm.2013.10.018] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2013] [Revised: 09/25/2013] [Accepted: 10/14/2013] [Indexed: 12/16/2022]
Abstract
Clinical neuropathologic studies suggest that the selective vulnerability of hippocampal CA1 pyramidal projection neurons plays a key role in the onset of cognitive impairment during the early phases of Alzheimer's disease (AD). Disruption of this neuronal population likely affects hippocampal pre- and postsynaptic efficacy underlying episodic memory circuits. Therefore, identifying perturbations in the expression of synaptic gene products within CA1 neurons prior to frank AD is crucial for the development of disease modifying therapies. Here we used custom-designed microarrays to examine progressive alterations in synaptic gene expression within CA1 neurons in cases harvested from the Rush Religious Orders Study who died with a clinical diagnosis of no cognitive impairment (NCI), mild cognitive impairment (MCI, a putative prodromal AD stage), or mild/moderate AD. Quantitative analysis revealed that 21 out of 28 different transcripts encoding regulators of synaptic function were significantly downregulated (1.4-1.8 fold) in CA1 neurons in MCI and AD compared to NCI, whereas synaptic transcript levels were not significantly different between MCI and AD. The downregulated transcripts encoded regulators of presynaptic vesicle trafficking, including synaptophysin and synaptogyrin, regulators of vesicle docking and fusion/release, such as synaptotagmin and syntaxin 1, and regulators of glutamatergic postsynaptic function, including PSD-95 and synaptopodin. Clinical pathologic correlation analysis revealed that downregulation of these synaptic markers was strongly associated with poorer antemortem cognitive status and postmortem AD pathological criteria such as Braak stage, NIA-Reagan, and CERAD diagnosis. In contrast to the widespread loss of synaptic gene expression observed in CA1 neurons in MCI, transcripts encoding β-amyloid precursor protein (APP), APP family members, and regulators of APP metabolism were not differentially regulated in CA1 neurons across the clinical diagnostic groups. Taken together, these data suggest that CA1 synaptic gene dysregulation occurs early in the cascade of pathogenic molecular events prior to the onset of AD, which may form the basis for novel pharmacological treatment approaches for this dementing disorder. This article is part of a Special Issue entitled 'Neurodegenerative Disorders'.
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Duning K, Wennmann DO, Bokemeyer A, Reissner C, Wersching H, Thomas C, Buschert J, Guske K, Franzke V, Flöel A, Lohmann H, Knecht S, Brand SM, Pöter M, Rescher U, Missler M, Seelheim P, Pröpper C, Boeckers TM, Makuch L, Huganir R, Weide T, Brand E, Pavenstädt H, Kremerskothen J. Common exonic missense variants in the C2 domain of the human KIBRA protein modify lipid binding and cognitive performance. Transl Psychiatry 2013; 3:e272. [PMID: 23778582 PMCID: PMC3693407 DOI: 10.1038/tp.2013.49] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
The human KIBRA gene has been linked to human cognition through a lead intronic single-nucleotide polymorphism (SNP; rs17070145) that is associated with episodic memory performance and the risk to develop Alzheimer's disease. However, it remains unknown how this relates to the function of the KIBRA protein. Here, we identified two common missense SNPs (rs3822660G/T [M734I], rs3822659T/G [S735A]) in exon 15 of the human KIBRA gene to affect cognitive performance, and to be in almost complete linkage disequilibrium with rs17070145. The identified SNPs encode variants of the KIBRA C2 domain with distinct Ca(2+) dependent binding preferences for monophosphorylated phosphatidylinositols likely due to differences in the dynamics and folding of the lipid-binding pocket. Our results further implicate the KIBRA protein in higher brain function and provide direction to the cellular pathways involved.
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Affiliation(s)
- K Duning
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, Münster, Germany
| | - D O Wennmann
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, Münster, Germany
| | - A Bokemeyer
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, Münster, Germany
| | - C Reissner
- Department of Anatomy and Molecular Neurobiology, University Münster, Münster, Germany
| | - H Wersching
- Institute of Epidemiology and Social Medicine, University of Münster, Münster, Germany
| | - C Thomas
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, Münster, Germany
| | - J Buschert
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, Münster, Germany
| | - K Guske
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, Münster, Germany
| | - V Franzke
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, Münster, Germany
| | - A Flöel
- Department of Neurology, University Hospital Münster, Münster, Germany
| | - H Lohmann
- Department of Neurology, University Hospital Münster, Münster, Germany
| | - S Knecht
- Department of Neurology, University Hospital Münster, Münster, Germany
| | - S-M Brand
- Institute of Sports Medicine, University of Münster, Münster, Germany
| | - M Pöter
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, Münster, Germany
| | - U Rescher
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, Münster, Germany
| | - M Missler
- Department of Anatomy and Molecular Neurobiology, University Münster, Münster, Germany
| | - P Seelheim
- Institute of Biochemistry, University of Münster, Münster, Germany
| | - C Pröpper
- Institute of Anatomy and Cell Biology, University Ulm, Ulm, Germany
| | - T M Boeckers
- Institute of Anatomy and Cell Biology, University Ulm, Ulm, Germany
| | - L Makuch
- Howard Hughes Medical Center, John Hopkins University, Baltimore, MD, USA
| | - R Huganir
- Howard Hughes Medical Center, John Hopkins University, Baltimore, MD, USA
| | - T Weide
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, Münster, Germany
| | - E Brand
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, Münster, Germany
| | - H Pavenstädt
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, Münster, Germany
| | - J Kremerskothen
- Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, Münster, Germany,Internal Medicine D, Department of Nephrology, Hypertension and Rheumatology, University Hospital Münster, Albert-Schweitzer-Campus 1, 48149 Münster, Germany. E-mail:
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35
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Rácz B, Weinberg RJ. Microdomains in forebrain spines: an ultrastructural perspective. Mol Neurobiol 2013; 47:77-89. [PMID: 22983912 PMCID: PMC3538892 DOI: 10.1007/s12035-012-8345-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2012] [Accepted: 08/27/2012] [Indexed: 12/21/2022]
Abstract
Glutamatergic axons in the mammalian forebrain terminate predominantly onto dendritic spines. Long-term changes in the efficacy of these excitatory synapses are tightly coupled to changes in spine morphology. The reorganization of the actin cytoskeleton underlying this spine "morphing" involves numerous proteins that provide the machinery needed for adaptive cytoskeletal remodeling. Here, we review recent literature addressing the chemical architecture of the spine, focusing mainly on actin-binding proteins (ABPs). Accumulating evidence suggests that ABPs are organized into functionally distinct microdomains within the spine cytoplasm. This functional compartmentalization provides a structural basis for regulation of the spinoskeleton, offering a novel window into mechanisms underlying synaptic plasticity.
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Affiliation(s)
- Bence Rácz
- Department of Anatomy and Histology, Faculty of Veterinary Science, Szent István University, 1078, Budapest, Hungary.
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36
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Myopodin is an F-actin bundling protein with multiple independent actin-binding regions. J Muscle Res Cell Motil 2012; 34:61-9. [PMID: 23225103 DOI: 10.1007/s10974-012-9334-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2012] [Accepted: 11/28/2012] [Indexed: 01/14/2023]
Abstract
The assembly of striated muscle myofibrils is a multistep process in which a variety of proteins is involved. One of the first and most important steps in myofibrillogenesis is the arrangement of thin myofilaments into ordered I-Z-I brushes, requiring the coordinated activity of numerous actin binding proteins. The early expression of myopodin prior to sarcomeric α-actinin, as well as its binding to actin, α-actinin and filamin indicate an important role for this protein in actin cytoskeleton remodelling with the precise function of myopodin in this process yet remaining to be resolved. While myopodin was previously described as a protein capable of cross-linking actin filaments into thick bundles upon transient transfections, it has remained unclear whether myopodin alone is capable of bundling actin, or if additional proteins are involved. We have therefore investigated the in vitro actin binding properties of myopodin. High speed cosedimentation assays with skeletal muscle actin confirmed direct binding of myopodin to F-actin and showed that this interaction is mediated by at least two independent actin binding sites, found in all myopodin isoforms identified to date. Furthermore, low-speed cosedimentation assays revealed that not only full length myopodin, but also the fragment containing only the second binding site, bundles microfilaments in the absence of accessory proteins. Ultrastructural analysis demonstrated that this bundling activity resembled that of α-actinin. Biochemical experiments revealed that bundling was not achieved by myopodin's ability to dimerize, indicating the presence of two individual F-actin binding sites within the second binding segment. Thus full length myopodin contains at least three F-actin binding sites. These data provide further understanding of the mechanisms by which myopodin contributes to actin reorganization during myofibril assembly.
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37
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GFP immunogold staining, from light to electron microscopy, in mammalian cells. Micron 2012; 43:589-99. [DOI: 10.1016/j.micron.2011.10.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 10/04/2011] [Accepted: 10/04/2011] [Indexed: 01/22/2023]
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38
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Vlachos A. Synaptopodin and the spine apparatus organelle-regulators of different forms of synaptic plasticity? Ann Anat 2011; 194:317-20. [PMID: 22217474 DOI: 10.1016/j.aanat.2011.10.014] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2011] [Revised: 10/24/2011] [Accepted: 10/25/2011] [Indexed: 11/27/2022]
Abstract
Synaptopodin (SP) is an actin-binding molecule, which is closely linked with the spine apparatus organelle (SA). Recent experimental evidence suggests that SP containing spines differ in their functional and structural properties from neighboring spines, which do not contain SP. These studies revealed for the first time that SP clusters colocalize with a functional internal source of calcium, which affects synaptic plasticity. Strikingly, SP-cluster associated calcium surges were shown to control synaptic strength in two ways: a ryanodine receptor (RyR) dependent potentiation of synaptic strength was reported, as well as inositol-triphosphate-receptor (IP3R) dependent depression. These results suggested that the SA is an important component of the molecular machinery controlling the calcium-dependent accumulation of AMPA-receptors (AMPA-R) at excitatory synapses. They raise the intriguing possibility that SP/SA could play a role in different forms of synaptic plasticity.
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Affiliation(s)
- Andreas Vlachos
- Institute of Clinical Neuroanatomy, Dr. Senckenberg Anatomy, Neuroscience Center, Goethe-University Frankfurt, Germany.
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39
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Niesmann K, Breuer D, Brockhaus J, Born G, Wolff I, Reissner C, Kilimann MW, Rohlmann A, Missler M. Dendritic spine formation and synaptic function require neurobeachin. Nat Commun 2011; 2:557. [PMID: 22109531 PMCID: PMC3482631 DOI: 10.1038/ncomms1565] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2011] [Accepted: 10/26/2011] [Indexed: 01/11/2023] Open
Abstract
A challenge in neuroscience is to understand the mechanisms underlying synapse
formation. Most excitatory synapses in the brain are built on spines, which are
actin-rich protrusions from dendrites. Spines are a major substrate of brain
plasticity, and spine pathologies are observed in various mental illnesses. Here we
investigate the role of neurobeachin (Nbea), a multidomain protein previously linked
to cases of autism, in synaptogenesis. We show that deletion of Nbea leads to
reduced numbers of spinous synapses in cultured neurons from complete knockouts and
in cortical tissue from heterozygous mice, accompanied by altered miniature
postsynaptic currents. In addition, excitatory synapses terminate mostly at
dendritic shafts instead of spine heads in Nbea mutants, and actin becomes less
enriched synaptically. As actin and synaptopodin, a spine-associated protein with
actin-bundling activity, accumulate ectopically near the Golgi apparatus of mutant
neurons, a role emerges for Nbea in trafficking important cargo to pre- and
postsynaptic compartments. Most excitatory synapses in the brain are found on dendritic
spines, but the mechanisms underlying synapse formation are poorly understood. Niesmann
et al. investigate the role of neurobeachin in synaptogenesis, and find that
its deletion leads to fewer spinous synapses and altered postsynaptic
currents.
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Affiliation(s)
- Katharina Niesmann
- Department of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, Münster 48149, Germany
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40
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Kalinichenko SV, Vikhreva PN, Korobko IV. Interaction between MAK-V protein kinase and synaptopodin. BIOCHEMISTRY (MOSCOW) 2011; 76:196-201. [PMID: 21568852 DOI: 10.1134/s0006297911020052] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
MAK-V protein kinase (also known as HUNK) was discovered more than decade ago but its functions and molecular mechanisms of action still remain mostly unknown. In an attempt to associate MAK-V with particular chains of molecular events, we searched for proteins interacting with the C-terminal domain of MAK-V protein kinase. We identified synaptopodin as a protein interaction partner for MAK-V and confirmed this interaction in various ways. Because synaptopodin is important for dendritic spine formation and plays a role in synaptic plasticity, our results might have significant impact on future studies for understanding the role of MAK-V in cells of the nervous system.
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Affiliation(s)
- S V Kalinichenko
- Institute of Gene Biology, Russian Academy of Sciences, Moscow, Russia.
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41
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Korkotian E, Segal M. Synaptopodin regulates release of calcium from stores in dendritic spines of cultured hippocampal neurons. J Physiol 2011; 589:5987-95. [PMID: 22025667 DOI: 10.1113/jphysiol.2011.217315] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
The presence of calcium stores and their function in dendritic spines is still unsettled. We have now studied the kinetics of calcium released inside dendritic spines of cultured rat hippocampal neurons by flash photolysis of caged calcium. Photolysis of calcium produced a fast rise in [Ca(2+)](i), followed by a variable decay. We were able to correlate the decay of elevated [Ca(2+)](i) with the presence of synaptopodin (SP), an actin-binding protein, in the spines; spines containing SP generated the same initial [Ca(2+)](i) transient, but their decay time was significantly slower and more complex than that of SP-negative ones. The altered decay kinetics of the flash-elevated [Ca(2+)](i) transient was blocked by thapsigargin or cyclopiazonic acid (CPA), indicating that this kinetic change is due to compartmentalized release of calcium from intracellular stores. Thus, SP plays a pivotal role in the calcium store-associated ability of spines to locally tune calcium kinetics.
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Affiliation(s)
- Eduard Korkotian
- Department of Neurobiology, The Weizmann Institute, 76100 Rehovot, Israel
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42
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Sanchez-Ponce D, Blazquez-Llorca L, DeFelipe J, Garrido JJ, Munoz A. Colocalization of -actinin and Synaptopodin in the Pyramidal Cell Axon Initial Segment. Cereb Cortex 2011; 22:1648-61. [DOI: 10.1093/cercor/bhr251] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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43
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A network of networks: cytoskeletal control of compartmentalized function within dendritic spines. Curr Opin Neurobiol 2011; 20:578-87. [PMID: 20667710 DOI: 10.1016/j.conb.2010.06.009] [Citation(s) in RCA: 58] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2010] [Revised: 06/04/2010] [Accepted: 06/26/2010] [Indexed: 12/19/2022]
Abstract
Almost 30 years ago, actin was identified as the major cytoskeletal component of dendritic spines. Since then, its role in the remarkable dynamics of spine morphology have been detailed with live-cell views establishing that spine shape dynamics are an important requirement for synaptogenesis and synaptic plasticity. However, the actin cytoskeleton is critical to numerous and varied processes within the spine which contribute to the maintenance and plasticity of synaptic function. Here, we argue that the spatial and temporal distribution of actin-dependent processes within spines suggests that the spine cytoskeleton should not be considered a single entity, but an interacting network of nodes or hubs that are independently regulated and balanced to maintain synapse function. Disruptions of this balance within the spine are likely to lead to psychiatric and neurological dysfunction.
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44
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In vitro maturation of the cisternal organelle in the hippocampal neuron's axon initial segment. Mol Cell Neurosci 2011; 48:104-16. [PMID: 21708259 DOI: 10.1016/j.mcn.2011.06.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2011] [Revised: 06/07/2011] [Accepted: 06/09/2011] [Indexed: 11/21/2022] Open
Abstract
Regulation of Ca(2+) concentrations is essential to maintain the structure and function of the axon initial segment (AIS). The so-called cisternal organelle of the AIS is a structure involved in this regulation, although little is known as to how this organelle matures and is stabilized. Here we describe how the cisternal organelle develops in cultured hippocampal neurons and the interactions that facilitate its stabilization in the AIS. We also characterize the developmental expression of molecules involved in Ca(2+) regulation in the AIS. Our results indicate that synaptopodin (synpo) positive elements considered to be associated to the cisternal organelle are present in the AIS after six days in vitro. There are largely overlapping microdomains containing the inositol 1,4,5-triphosphate receptor 1 (IP(3)R1) and the Ca(2+) binding protein annexin 6, suggesting that the regulation of Ca(2+) concentrations in the AIS is sensitive to IP(3) and subject to regulation by annexin 6. The expression of synpo, IP(3)R1 and annexin 6 in the AIS is independent of the neuron activity, as it was unaffected by tetrodotoxin blockage of action potentials and it was resistant to detergent extraction, indicating that these proteins interact with scaffolding and/or cytoskeleton proteins. The presence of ankyrin G seems to be required for the acquisition and maintenance of the cisternal organelle, while the integrity of the actin cytoskeleton must be maintained for the expression IP(3)R1 and annexin 6 to persist in the AIS.
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45
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Li M, Armelloni S, Ikehata M, Corbelli A, Pesaresi M, Calvaresi N, Giardino L, Mattinzoli D, Nisticò F, Andreoni S, Puliti A, Ravazzolo R, Forloni G, Messa P, Rastaldi MP. Nephrin expression in adult rodent central nervous system and its interaction with glutamate receptors. J Pathol 2011; 225:118-28. [PMID: 21630272 DOI: 10.1002/path.2923] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2011] [Revised: 04/05/2011] [Accepted: 04/13/2011] [Indexed: 12/22/2022]
Abstract
Nephrin is an immunoglobulin-like adhesion molecule first discovered as a major component of the podocyte slit diaphragm, where its integrity is essential to the function of the glomerular filtration barrier. Outside the kidney, nephrin has been shown in other restricted locations, most notably in the central nervous system (CNS) of embryonic and newborn rodents. With the aim of better characterizing nephrin expression and its role in the CNS of adult rodents, we studied its expression pattern and possible binding partners in CNS tissues and cultured neuronal cells and compared these data to those obtained in control renal tissues and podocyte cell cultures. Our results show that, besides a number of locations already found in embryos and newborns, endogenous nephrin in adult rodent CNS extends to the pons and corpus callosum and is expressed by granule cells and Purkinje cells of the cerebellum, with a characteristic alternating expression pattern. In primary neuronal cells we find nephrin expression close to synaptic proteins and demonstrate that nephrin co-immunoprecipitates with Fyn kinase, glutamate receptors and the scaffolding molecule PSD95, an assembly that is reminiscent of those made by synaptic adhesion molecules. This role seems to be confirmed by our findings of impaired maturation and reduced glutamate exocytosis occurring in Neuro2A cells upon nephrin silencing. Of note, we disclose that the very same nephrin interactions occur in renal glomeruli and cultured podocytes, supporting our hypothesis that podocytes organize and use similar molecular intercellular signalling modules to those used by neuronal cells.
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Affiliation(s)
- Min Li
- Renal Research Laboratory, Department of Nephrology, Dialysis and Renal Transplantation, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico and Fondazione D'Amico per la Ricerca sulle Malattie Renali, Milan, Italy
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Cohen JW, Louneva N, Han LY, Hodes GE, Wilson RS, Bennett DA, Lucki I, Arnold SE. Chronic corticosterone exposure alters postsynaptic protein levels of PSD-95, NR1, and synaptopodin in the mouse brain. Synapse 2011; 65:763-70. [PMID: 21190219 DOI: 10.1002/syn.20900] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2010] [Accepted: 12/02/2010] [Indexed: 02/06/2023]
Abstract
Animal models provide compelling evidence that chronic stress is associated with biochemical and morphological changes in the brain, many of which are mediated by corticosterone, a principal glucocorticoid synthesized in the rodent adrenal cortex and secreted in response to stress. To better characterize the effects of chronic corticosterone at the synaptic and subsynaptic level, we implanted three-month-old male C57B/6 mice with 2 × 5 mg corticosterone pellets (CORT group, n = 14), 21 day release formulation (20 mg/kg/day dose) or placebo pellets (Placebo group, n = 14), 21-day release formulation. After 20 days, brains were removed. One hemisphere was frozen for biochemical analysis by synaptosomal fractionation with Western blotting, and the other hemisphere was fixed for immunohistochemistry. Localization and expression levels for PSD-95, NR1, and synaptopodin proteins were assessed. Biochemical analysis revealed lower protein levels of PSD-95 (32% decrease, P < 0.001), NR1 (47%, P = 0.01), and synaptopodin (65%, P < 0.001) in the postsynaptic density subsynaptic fraction of the CORT group. Optical densitometry in immunohistochemically labeled sections also found lower levels of PSD-95 in synaptic fields of the dentate gyrus (PSD-95, 33% decrease, P < 0.001; NR1, 31%, P < 0.001; synaptopodin, 40%, P < 0.001) and the CA3 stratum lucidum (36%, P < 0.001, 40%, P < 0.001, and 35%, P < 0.001) of the CORT group. While mechanistic relationships for these changes are not yet known, we speculate that synaptopodin, which is involved in regulation of spine calcium kinetics and posttranslational modification and transport of locally synthesized proteins, may play an important role in the changes of PSD-95 and NR1 protein levels and other synaptic alterations.
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Affiliation(s)
- Julia W Cohen
- Department of Psychiatry, Center for Neurobiology and Behavior, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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Chalovich JM, Schroeter MM. Synaptopodin family of natively unfolded, actin binding proteins: physical properties and potential biological functions. Biophys Rev 2010; 2:181-189. [PMID: 28510039 PMCID: PMC5418383 DOI: 10.1007/s12551-010-0040-5] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 11/01/2010] [Indexed: 12/15/2022] Open
Abstract
The synaptopodin family of proteins consists of at least 3 members: synaptopodin, the synaptopodin 2 proteins, and the synaptopodin 2-like proteins. Each family member has at least 3 isoforms that are produced by alternative splicing. Synaptopodin family members are basic proteins that are rich in proline and have little regular 2° or 3° structure at physiological temperature, pH and ionic strength. Like other natively unfolded proteins, synaptopodin family members have multiple binding partners including actin and other actin-binding proteins. Several members of the synaptopodin family have been shown to stimulate actin polymerization and to bundle actin filaments either on their own or in collaboration with other proteins. Synaptopodin 2 has been shown to accelerate nucleation of actin filament formation and to induce actin bundling. The actin polymerization activity is inhibited by Ca2+-calmodulin. Synaptopodin 2 proteins are localized in Z-bands of striated and heart muscle and dense bodies of smooth muscle cells. Depending on the developmental status and stress, at least one member of the synaptopodin family can occupy nuclei of some cells. Members of the synaptopodin 2 subfamily have been implicated in cancers.
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Affiliation(s)
- Joseph M Chalovich
- Department of Biochemistry and Molecular Biology, Brody School of Medicine at East Carolina University, 5E-122 Brody Medical Sciences Building, 600 Moye Blvd, Greenville, NC, 27834, USA.
| | - Mechthild M Schroeter
- Department of Physiology, University of Cologne, Robert-Koch-Str. 39, 50931, Cologne, Germany
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Kim EY, Suh JM, Chiu YH, Dryer SE. Regulation of podocyte BK(Ca) channels by synaptopodin, Rho, and actin microfilaments. Am J Physiol Renal Physiol 2010; 299:F594-604. [PMID: 20630939 DOI: 10.1152/ajprenal.00206.2010] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Mechanosensitive large-conductance Ca(2+)-activated K(+) channels encoded by the Slo1 gene (BK(Ca) channels) are expressed in podocytes. Here we show that BK(Ca) channels reciprocally coimmunoprecipitate with synaptopodin (Synpo) in mouse glomeruli, in mouse podocytes, and in a heterologous expression system (HEK293T cells) in which these proteins are transiently expressed. Synpo and Slo1 colocalize along the surface of the glomerular basement membrane in mouse glomeruli. Synpo interacts with BK(Ca) channels at COOH-terminal domains that overlap with an actin-binding domain on the channel molecule that is necessary for trafficking of BK(Ca) channels to the cell surface. Moreover, addition of exogenous beta-actin to mouse podocyte lysates reduces BK(Ca)-Synpo interactions. Coexpression of Synpo increases steady-state surface expression of BK(Ca) channels in HEK293T cells. However, Synpo does not affect the stability of cell surface BK(Ca) channels, suggesting a primary effect on the rate of forward trafficking, and Synpo coexpression does not affect BK(Ca) gating. Conversely, stable knockdown of Synpo expression in mouse podocyte cell lines reduces steady-state surface expression of BK(Ca) channels but does not affect total expression of BK(Ca) channels or their gating. The effects of Synpo on surface expression of BK(Ca) are blocked by inhibition of Rho signaling in HEK293T cells and in podocytes. Functional cell surface BK(Ca) channels in podocytes are also reduced by sustained (2 h) but not acute (15 min) depolymerization of actin with cytochalasin D. Synpo may regulate BK(Ca) channels through its effects on actin dynamics and by modulating interactions between BK(Ca) channels and regulatory proteins of the podocyte slit diaphragm.
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Affiliation(s)
- Eun Young Kim
- Department of Biology and Biochemistry, University of Houston, Texas 77204-5001, USA
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Segal M, Vlachos A, Korkotian E. The Spine Apparatus, Synaptopodin, and Dendritic Spine Plasticity. Neuroscientist 2010; 16:125-31. [DOI: 10.1177/1073858409355829] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The spine apparatus (SA) is an essential component of mature dendritic spines of cortical and hippocampal neurons, yet its functions are still enigmatic. Synaptopodin (SP), an actin-binding protein, colocalizes with the SA. Hippocampal neurons in SP-knockout mice lack SA, and they express lower LTP. SP probably plays a role in synaptic plasticity, but only recently it is being linked mechanistically to synaptic functions. These authors and others have studied endogenous and transfected SP in dendritic spines of cultured hippocampal neurons. They found that spines containing SP generate twice as large responses to flash photolysis of caged glutamate than SP-negative ones. An N-methyl-d-aspartate receptor—mediated chemical LTP caused accumulation of GFP-GluR1 in spine heads of control but not of shRNA transfected, SP-deficient neurons. SP is linked to calcium stores, because their pharmacological blockade eliminated SP-related enhancement of glutamate responses. Furthermore, release of calcium from stores produces an SP-dependent delivery of GluR1 into spines. Thus, SP plays a crucial role in the calcium store-associated ability of neurons to undergo long-term plasticity.
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Affiliation(s)
- Menahem Segal
- Department of Neurobiology, The Weizmann Institute, Rehovot, Israel,
| | - Andreas Vlachos
- Institute of Clinical Neuroanatomy, Neuroscience Center, Goethe-University Frankfurt, Frankfurt, Germany
| | - Eduard Korkotian
- Department of Neurobiology, The Weizmann Institute, Rehovot, Israel
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Schneider A, Huentelman MJ, Kremerskothen J, Duning K, Spoelgen R, Nikolich K. KIBRA: A New Gateway to Learning and Memory? Front Aging Neurosci 2010; 2:4. [PMID: 20552044 PMCID: PMC2874402 DOI: 10.3389/neuro.24.004.2010] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 01/22/2010] [Indexed: 11/28/2022] Open
Abstract
The genetic locus encoding KIBRA, a member of the WWC family of proteins, has recently been shown to be associated with human memory performance through genome-wide single nucleotide polymorphism screening. Gene expression analysis and a variety of functional studies have further indicated that such a role is biologically plausible for KIBRA. Here, we review the existing literature, illustrate connections between the different lines of evidence, and derive models based on KIBRA's function(s) in the brain that can be further tested experimentally.
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