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Wischmann J, Borowski K, Havla J, Thaler FS, Winkler T, Jung T, Straube A, Masouris I. Case report: Anti septin-5-encephalitis as a treatable cause of cerebellar ataxia and psychiatric symptoms. Front Neurol 2023; 14:1220295. [PMID: 37435157 PMCID: PMC10331165 DOI: 10.3389/fneur.2023.1220295] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 06/08/2023] [Indexed: 07/13/2023] Open
Abstract
Objectives Anti-septin-5 encephalitis is a rare disease with only few published cases, mainly based on retrospective CSF and serum analyses. Predominant symptoms are cerebellar ataxia and oculomotor abnormalities. Due to the rareness of the disease, treatment recommendations are scarce. Herein, we prospectively describe the clinical course of a female patient with anti-septin-5 encephalitis. Methods We describe diagnostic workup, treatment and follow-up of a 54-year-old patient presenting with vertigo, unsteady gait, lack of drive and behavioral changes. Results Clinical examination revealed severe cerebellar ataxia, saccadic smooth pursuit, upbeat-nystagmus, and dysarthria. Additionally, the patient presented with a depressive syndrome. MRI of the brain and spinal cord were normal. CSF analysis showed lymphocytic pleocytosis (11 cells/μl). Extensive antibody testing revealed anti septin-5 IgG in both CSF and serum without coexisting anti-neuronal antibodies. PET/CT detected no signs of malignancy. Corticosteroids, plasma exchange, and rituximab led to transient clinical improvement followed by relapse. Re-applied treatment with plasma exchange followed by bortezomib resulted in moderate but sustained clinical improvement. Discussion Anti septin-5 encephalitis represents a rare but treatable and therefore relevant differential diagnosis in patients with cerebellar ataxia. Psychiatric symptoms can be observed in anti septin-5 encephalitis. Immunosuppressive treatment including bortezomib is moderately effective.
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Affiliation(s)
- Johannes Wischmann
- Department of Neurology, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Kathrin Borowski
- Clinical Immunological Laboratory Prof. Dr. med. Winfried Stöcker, Luebeck, Germany
| | - Joachim Havla
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany
- Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität Munich, Munich, Germany
| | - Franziska S. Thaler
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians-Universität Munich, Munich, Germany
- Biomedical Center, Medical Faculty, Ludwig-Maximilians-Universität Munich, Munich, Germany
- Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Tobias Winkler
- Department of Neurology, kbo-Inn-Salzach-Klinikum, Wasserburg am Inn, Germany
| | - Tobias Jung
- Department of Neurology, kbo-Inn-Salzach-Klinikum, Wasserburg am Inn, Germany
| | - Andreas Straube
- Department of Neurology, University Hospital, Ludwig-Maximilians-University, Munich, Germany
| | - Ilias Masouris
- Department of Neurology, University Hospital, Ludwig-Maximilians-University, Munich, Germany
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Grigoryev PN, Khisamieva GA, Zefirov AL. Septin Polymerization Slows Synaptic Vesicle Recycling in Motor Nerve Endings. Acta Naturae 2019; 11:54-62. [PMID: 31413880 PMCID: PMC6643342 DOI: 10.32607/20758251-2019-11-2-54-62] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Indexed: 11/20/2022] Open
Abstract
Septins are GTP-binding proteins recognized as a component of the cytoskeleton. Despite the fact that septins are highly expressed by neurons and can interact with the proteins that participate in synaptic vesicle exocytosis and endocytosis, the role of septins in synaptic transmission and the synaptic vesicle recycling mechanisms is poorly understood. In this study, neurotransmitter release and synaptic vesicle exocytosis and endocytosis were investigated by microelectrode intracellular recording of end-plate potentials and fluorescent confocal microscopy in mouse diaphragm motor nerve endings during septin polymerization induced by forchlorfenuron application. It was shown that forchlorfenuron application reduces neurotransmission during prolonged high-frequency (20 and 50 pulses/s) stimulation. Application of pairs of short high-frequency stimulation trains showed that forchlorfenuron slows the replenishment of the readily releasable pool. Forchlorfenuron enhanced FM 1-43 fluorescent dye loading by synaptic vesicle endocytosis but decreased dye unloading from the preliminarily stained nerve endings by synaptic vesicle exocytosis. It was concluded that the septin polymerization induced by forchlorfenuron application slows the rate of synaptic vesicle recycling in motor nerve endings due to the impairment of synaptic vesicle transport.
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Affiliation(s)
- P. N. Grigoryev
- Kazan State Medical University, Butlerova Str. 49, Kazan, 420012, Russia
| | - G. A. Khisamieva
- Kazan State Medical University, Butlerova Str. 49, Kazan, 420012, Russia
| | - A. L. Zefirov
- Kazan State Medical University, Butlerova Str. 49, Kazan, 420012, Russia
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3
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Ueno S, Miyoshi H, Maruyama Y, Morita M, Maekawa S. Interaction of dynamin I with NAP-22, a neuronal protein enriched in the presynaptic region. Neurosci Lett 2018; 675:59-63. [PMID: 29604406 DOI: 10.1016/j.neulet.2018.03.061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2018] [Revised: 03/24/2018] [Accepted: 03/28/2018] [Indexed: 10/17/2022]
Abstract
Neurons have well-developed membrane microdomains called "rafts" that are recovered as a detergent-resistant low-density membrane microdomain fraction (DRM). NAP-22 is one of the major protein components of neuronal DRM and localizes in the presynaptic region. In order to know the role of NAP-22 in the synaptic transmission, NAP-22 binding proteins in the cytosol were searched with an affinity screening with NAP-22 as a bait and several protein bands were detected. Using mass-analysis and western blotting, one of the main band of ∼90 kDa was identified as dynamin I. The GTPase activity of dynamin I was partly inhibited by NAP-22 expressed in bacteria and this inhibition was recovered by the addition of calmodulin, a NAP-22 binding protein. The GTPase activity of dynamin was known to be activated with acidic membrane lipids such as phosphatidylserine and the addition of NAP-22, a phosphatidylserine binding protein, inhibited the activation of the GTPase by this lipid. Since NAP-22 localizes on the presynaptic plasma membrane and on synaptic vesicles, these results suggest the participation of NAP-22 in the membrane cycling through binding to dynamin and acidic membrane lipids at the presynaptic region.
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Affiliation(s)
- Satoko Ueno
- Department of Biology, Graduate School of Science, Kobe-University, Kobe, 657-8501, Japan
| | - Hiroshi Miyoshi
- Department of Microbiology, St. Marianna University School of Medicine, 2-16-1 Sugao, Miyamae, Kawasaki, 216-8511, Japan
| | - Yoko Maruyama
- Department of Biology, Graduate School of Science, Kobe-University, Kobe, 657-8501, Japan
| | - Mitsuhiro Morita
- Department of Biology, Graduate School of Science, Kobe-University, Kobe, 657-8501, Japan
| | - Shohei Maekawa
- Department of Biology, Graduate School of Science, Kobe-University, Kobe, 657-8501, Japan.
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4
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Moreno-Castellanos N, Rodríguez A, Rabanal-Ruiz Y, Fernández-Vega A, López-Miranda J, Vázquez-Martínez R, Frühbeck G, Malagón MM. The cytoskeletal protein septin 11 is associated with human obesity and is involved in adipocyte lipid storage and metabolism. Diabetologia 2017; 60:324-335. [PMID: 27866222 DOI: 10.1007/s00125-016-4155-5] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2016] [Accepted: 10/25/2016] [Indexed: 11/28/2022]
Abstract
AIMS/HYPOTHESIS Septins are newly identified members of the cytoskeleton that have been proposed as biomarkers of a number of diseases. However, septins have not been characterised in adipose tissue and their relationship with obesity and insulin resistance remains unknown. Herein, we characterised a member of this family, septin 11 (SEPT11), in human adipose tissue and analysed its potential involvement in the regulation of adipocyte metabolism. METHODS Gene and protein expression levels of SEPT11 were analysed in human adipose tissue. SEPT11 distribution was evaluated by immunocytochemistry, electron microscopy and subcellular fractionation techniques. Glutathione S-transferase (GST) pull-down, immunoprecipitation and yeast two-hybrid screening were used to identify the SEPT11 interactome. Gene silencing was used to assess the role of SEPT11 in the regulation of insulin signalling and lipid metabolism in adipocytes. RESULTS We demonstrate the expression of SEPT11 in human adipocytes and its upregulation in obese individuals, with SEPT11 mRNA content positively correlating with variables of insulin resistance in subcutaneous adipose tissue. SEPT11 content was regulated by lipogenic, lipolytic and proinflammatory stimuli in human adipocytes. SEPT11 associated with caveolae in mature adipocytes and interacted with both caveolin-1 and the intracellular fatty acid chaperone, fatty acid binding protein 5 (FABP5). Lipid loading of adipocytes caused the association of the three proteins with the surface of lipid droplets. SEPT11 silencing impaired insulin signalling and insulin-induced lipid accumulation in adipocytes. CONCLUSIONS/INTERPRETATION Our findings support a role for SEPT11 in lipid traffic and metabolism in adipocytes and open new avenues for research on the control of lipid storage in obesity and insulin resistance.
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Affiliation(s)
- Natalia Moreno-Castellanos
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)/University of Córdoba/Reina Sofia University Hospital, Edificio IMIBIC, Avda. Menéndez Pidal s/n, 14004, Córdoba, Spain
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Spain
| | - Amaia Rodríguez
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Spain
- Metabolic Research Laboratory, Clínica Universidad de Navarra, IdiSNA, Pamplona, Spain
| | - Yoana Rabanal-Ruiz
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)/University of Córdoba/Reina Sofia University Hospital, Edificio IMIBIC, Avda. Menéndez Pidal s/n, 14004, Córdoba, Spain
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Spain
| | - Alejandro Fernández-Vega
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)/University of Córdoba/Reina Sofia University Hospital, Edificio IMIBIC, Avda. Menéndez Pidal s/n, 14004, Córdoba, Spain
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Spain
| | - José López-Miranda
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Spain
- Lipids and Atherosclerosis Unit, IMIBIC/Reina Sofia University Hospital/University of Córdoba, Córdoba, Spain
| | - Rafael Vázquez-Martínez
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)/University of Córdoba/Reina Sofia University Hospital, Edificio IMIBIC, Avda. Menéndez Pidal s/n, 14004, Córdoba, Spain
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Córdoba, Spain
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Spain
| | - Gema Frühbeck
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Spain, .
- Metabolic Research Laboratory, Clínica Universidad de Navarra, IdiSNA, Pamplona, Spain.
- Department of Endocrinology & Nutrition, Clínica Universidad de Navarra, Avda. Pío XII 36, 31008, Pamplona, Spain.
| | - María M Malagón
- Instituto Maimónides de Investigación Biomédica de Córdoba (IMIBIC)/University of Córdoba/Reina Sofia University Hospital, Edificio IMIBIC, Avda. Menéndez Pidal s/n, 14004, Córdoba, Spain.
- Department of Cell Biology, Physiology and Immunology, University of Cordoba, Córdoba, Spain.
- CIBER Fisiopatología de la Obesidad y Nutrición (CIBEROBN), Instituto de Salud Carlos III, Spain, .
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Vagin O, Beenhouwer DO. Septins: Regulators of Protein Stability. Front Cell Dev Biol 2016; 4:143. [PMID: 28066764 PMCID: PMC5168428 DOI: 10.3389/fcell.2016.00143] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Accepted: 12/02/2016] [Indexed: 12/31/2022] Open
Abstract
Septins are small GTPases that play a role in several important cellular processes. In this review, we focus on the roles of septins in protein stabilization. Septins may regulate protein stability by: (1) interacting with proteins involved in degradation pathways, (2) regulating the interaction between transmembrane proteins and cytoskeletal proteins, (3) affecting the mobility of transmembrane proteins in lipid bilayers, and (4) modulating the interaction of proteins with their adaptor or signaling proteins. In this context, we discuss the role of septins in protecting four different proteins from degradation. First we consider botulinum neurotoxin serotype A (BoNT/A) and the contribution of septins to its extraordinarily long intracellular persistence. Next, we discuss the role of septins in stabilizing the receptor tyrosine kinases EGFR and ErbB2. Finally, we consider the contribution of septins in protecting hypoxia-inducible factor 1α (HIF-1α) from degradation.
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Affiliation(s)
- Olga Vagin
- Department of Physiology, Geffen School of Medicine at UCLALos Angeles, CA, USA; VA Greater Los Angeles Healthcare SystemLos Angeles, CA, USA
| | - David O Beenhouwer
- Department of Medicine, Geffen School of Medicine at UCLALos Angeles, CA, USA; Division of Infectious Diseases, VA Greater Los Angeles Health Care SystemLos Angeles, CA, USA
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Song K, Russo G, Krauss M. Septins As Modulators of Endo-Lysosomal Membrane Traffic. Front Cell Dev Biol 2016; 4:124. [PMID: 27857942 PMCID: PMC5093113 DOI: 10.3389/fcell.2016.00124] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Accepted: 10/19/2016] [Indexed: 11/13/2022] Open
Abstract
Septins constitute a family of GTP-binding proteins, which assemble into non-polar filaments in a nucleotide-dependent manner. These filaments can be recruited to negatively charged membrane surfaces. When associated with membranes septin filaments can act as diffusion barriers, which confine subdomains of distinct biological functions. In addition, they serve scaffolding roles by recruiting cytosolic proteins and other cytoskeletal elements. Septins have been implicated in a large variety of membrane-dependent processes, including cytokinesis, signaling, cell migration, and membrane traffic, and several family members have been implicated in disease. However, surprisingly little is known about the molecular mechanisms underlying their biological functions. This review summarizes evidence in support of regulatory roles of septins during endo-lysosomal sorting, with a particular focus on phosphoinositides, which serve as spatial landmarks guiding septin recruitment to distinct subcellular localizations.
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Affiliation(s)
- Kyungyeun Song
- Leibniz-Institut für Molekulare Pharmakologie Berlin, Germany
| | - Giulia Russo
- Leibniz-Institut für Molekulare Pharmakologie Berlin, Germany
| | - Michael Krauss
- Leibniz-Institut für Molekulare Pharmakologie Berlin, Germany
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7
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Pagliuso A, Tham TN, Stevens JK, Lagache T, Persson R, Salles A, Olivo-Marin JC, Oddos S, Spang A, Cossart P, Stavru F. A role for septin 2 in Drp1-mediated mitochondrial fission. EMBO Rep 2016; 17:858-73. [PMID: 27215606 PMCID: PMC5278612 DOI: 10.15252/embr.201541612] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 04/01/2016] [Indexed: 11/09/2022] Open
Abstract
Mitochondria are essential eukaryotic organelles often forming intricate networks. The overall network morphology is determined by mitochondrial fusion and fission. Among the multiple mechanisms that appear to regulate mitochondrial fission, the ER and actin have recently been shown to play an important role by mediating mitochondrial constriction and promoting the action of a key fission factor, the dynamin‐like protein Drp1. Here, we report that the cytoskeletal component septin 2 is involved in Drp1‐dependent mitochondrial fission in mammalian cells. Septin 2 localizes to a subset of mitochondrial constrictions and directly binds Drp1, as shown by immunoprecipitation of the endogenous proteins and by pulldown assays with recombinant proteins. Depletion of septin 2 reduces Drp1 recruitment to mitochondria and results in hyperfused mitochondria and delayed FCCP‐induced fission. Strikingly, septin depletion also affects mitochondrial morphology in Caenorhabditis elegans, strongly suggesting that the role of septins in mitochondrial dynamics is evolutionarily conserved.
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Affiliation(s)
- Alessandro Pagliuso
- Unité des Interactions Bactéries-Cellules, Institut Pasteur, Paris, France U604 Inserm, Paris, France USC2020 INRA, Paris, France
| | - To Nam Tham
- Unité des Interactions Bactéries-Cellules, Institut Pasteur, Paris, France U604 Inserm, Paris, France USC2020 INRA, Paris, France
| | | | - Thibault Lagache
- Unité d'Analyse d'Images Biologiques Institut Pasteur, Paris, France CNRS UMR 3691, Paris, France
| | | | | | | | | | - Anne Spang
- Biozentrum University of Basel, Basel, Switzerland
| | - Pascale Cossart
- Unité des Interactions Bactéries-Cellules, Institut Pasteur, Paris, France U604 Inserm, Paris, France USC2020 INRA, Paris, France
| | - Fabrizia Stavru
- Unité des Interactions Bactéries-Cellules, Institut Pasteur, Paris, France U604 Inserm, Paris, France USC2020 INRA, Paris, France
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Dolat L, Hu Q, Spiliotis ET. Septin functions in organ system physiology and pathology. Biol Chem 2014; 395:123-41. [PMID: 24114910 DOI: 10.1515/hsz-2013-0233] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 10/08/2013] [Indexed: 02/07/2023]
Abstract
Human septins comprise a family of 13 genes that encode for >30 protein isoforms with ubiquitous and tissue-specific expressions. Septins are GTP-binding proteins that assemble into higher-order oligomers and filamentous polymers, which associate with cell membranes and the cytoskeleton. In the last decade, much progress has been made in understanding the biochemical properties and cell biological functions of septins. In parallel, a growing number of studies show that septins play important roles for the development and physiology of specific tissues and organs. Here, we review the expression and function of septins in the cardiovascular, immune, nervous, urinary, digestive, respiratory, endocrine, reproductive, and integumentary organ systems. Furthermore, we discuss how the tissue-specific functions of septins relate to the pathology of human diseases that arise from aberrations in septin expression.
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