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Božić M, Pirnat S, Fink K, Potokar M, Kreft M, Zorec R, Stenovec M. Ketamine Reduces the Surface Density of the Astroglial Kir4.1 Channel and Inhibits Voltage-Activated Currents in a Manner Similar to the Action of Ba 2+ on K + Currents. Cells 2023; 12:1360. [PMID: 37408194 DOI: 10.3390/cells12101360] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 05/04/2023] [Accepted: 05/05/2023] [Indexed: 07/07/2023] Open
Abstract
A single sub-anesthetic dose of ketamine evokes rapid and long-lasting beneficial effects in patients with a major depressive disorder. However, the mechanisms underlying this effect are unknown. It has been proposed that astrocyte dysregulation of extracellular K+ concentration ([K+]o) alters neuronal excitability, thus contributing to depression. We examined how ketamine affects inwardly rectifying K+ channel Kir4.1, the principal regulator of K+ buffering and neuronal excitability in the brain. Cultured rat cortical astrocytes were transfected with plasmid-encoding fluorescently tagged Kir4.1 (Kir4.1-EGFP) to monitor the mobility of Kir4.1-EGFP vesicles at rest and after ketamine treatment (2.5 or 25 µM). Short-term (30 min) ketamine treatment reduced the mobility of Kir4.1-EGFP vesicles compared with the vehicle-treated controls (p < 0.05). Astrocyte treatment (24 h) with dbcAMP (dibutyryl cyclic adenosine 5'-monophosphate, 1 mM) or [K+]o (15 mM), which increases intracellular cAMP, mimicked the ketamine-evoked reduction of mobility. Live cell immunolabelling and patch-clamp measurements in cultured mouse astrocytes revealed that short-term ketamine treatment reduced the surface density of Kir4.1 and inhibited voltage-activated currents similar to Ba2+ (300 µM), a Kir4.1 blocker. Thus, ketamine attenuates Kir4.1 vesicle mobility, likely via a cAMP-dependent mechanism, reduces Kir4.1 surface density, and inhibits voltage-activated currents similar to Ba2+, known to block Kir4.1 channels.
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Affiliation(s)
- Mićo Božić
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Department of Medical Oncology, Institute of Oncology Ljubljana, Zaloška 2, 1000 Ljubljana, Slovenia
| | - Samo Pirnat
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
| | - Katja Fink
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
| | - Maja Potokar
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
- Department of Biology, Biotechnical Faculty, University of Ljubljana, 1000 Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia
- Celica Biomedical, Tehnološki Park 24, 1000 Ljubljana, Slovenia
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Papiri G, D’Andreamatteo G, Cacchiò G, Alia S, Silvestrini M, Paci C, Luzzi S, Vignini A. Multiple Sclerosis: Inflammatory and Neuroglial Aspects. Curr Issues Mol Biol 2023; 45:1443-1470. [PMID: 36826039 PMCID: PMC9954863 DOI: 10.3390/cimb45020094] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/28/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023] Open
Abstract
Multiple sclerosis (MS) represents the most common acquired demyelinating disorder of the central nervous system (CNS). Its pathogenesis, in parallel with the well-established role of mechanisms pertaining to autoimmunity, involves several key functions of immune, glial and nerve cells. The disease's natural history is complex, heterogeneous and may evolve over a relapsing-remitting (RRMS) or progressive (PPMS/SPMS) course. Acute inflammation, driven by infiltration of peripheral cells in the CNS, is thought to be the most relevant process during the earliest phases and in RRMS, while disruption in glial and neural cells of pathways pertaining to energy metabolism, survival cascades, synaptic and ionic homeostasis are thought to be mostly relevant in long-standing disease, such as in progressive forms. In this complex scenario, many mechanisms originally thought to be distinctive of neurodegenerative disorders are being increasingly recognized as crucial from the beginning of the disease. The present review aims at highlighting mechanisms in common between MS, autoimmune diseases and biology of neurodegenerative disorders. In fact, there is an unmet need to explore new targets that might be involved as master regulators of autoimmunity, inflammation and survival of nerve cells.
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Affiliation(s)
- Giulio Papiri
- Neurology Unit, Ospedale Provinciale “Madonna del Soccorso”, 63074 San Benedetto del Tronto, Italy
| | - Giordano D’Andreamatteo
- Neurology Unit, Ospedale Provinciale “Madonna del Soccorso”, 63074 San Benedetto del Tronto, Italy
| | - Gabriella Cacchiò
- Neurology Unit, Ospedale Provinciale “Madonna del Soccorso”, 63074 San Benedetto del Tronto, Italy
| | - Sonila Alia
- Section of Biochemistry, Biology and Physics, Department of Clinical Sciences, Università Politecnica delle Marche, 60100 Ancona, Italy
| | - Mauro Silvestrini
- Neurology Unit, Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60100 Ancona, Italy
| | - Cristina Paci
- Neurology Unit, Ospedale Provinciale “Madonna del Soccorso”, 63074 San Benedetto del Tronto, Italy
| | - Simona Luzzi
- Neurology Unit, Department of Experimental and Clinical Medicine, Università Politecnica delle Marche, 60100 Ancona, Italy
| | - Arianna Vignini
- Section of Biochemistry, Biology and Physics, Department of Clinical Sciences, Università Politecnica delle Marche, 60100 Ancona, Italy
- Correspondence:
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3
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Rituper B, Guček A, Lisjak M, Gorska U, Šakanović A, Bobnar ST, Lasič E, Božić M, Abbineni PS, Jorgačevski J, Kreft M, Verkhratsky A, Platt FM, Anderluh G, Stenovec M, Božič B, Coorssen JR, Zorec R. Vesicle cholesterol controls exocytotic fusion pore. Cell Calcium 2021; 101:102503. [PMID: 34844123 DOI: 10.1016/j.ceca.2021.102503] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2021] [Revised: 11/15/2021] [Accepted: 11/16/2021] [Indexed: 12/24/2022]
Abstract
In some lysosomal storage diseases (LSD) cholesterol accumulates in vesicles. Whether increased vesicle cholesterol affects vesicle fusion with the plasmalemma, where the fusion pore, a channel between the vesicle lumen and the extracellular space, is formed, is unknown. Super-resolution microscopy revealed that after stimulation of exocytosis, pituitary lactotroph vesicles discharge cholesterol which transfers to the plasmalemma. Cholesterol depletion in lactotrophs and astrocytes, both exhibiting Ca2+-dependent exocytosis regulated by distinct Ca2+sources, evokes vesicle secretion. Although this treatment enhanced cytosolic levels of Ca2+ in lactotrophs but decreased it in astrocytes, this indicates that cholesterol may well directly define the fusion pore. In an attempt to explain this mechanism, a new model of cholesterol-dependent fusion pore regulation is proposed. High-resolution membrane capacitance measurements, used to monitor fusion pore conductance, a parameter related to fusion pore diameter, confirm that at resting conditions reducing cholesterol increases, while enrichment with cholesterol decreases the conductance of the fusion pore. In resting fibroblasts, lacking the Npc1 protein, a cellular model of LSD in which cholesterol accumulates in vesicles, the fusion pore conductance is smaller than in controls, showing that vesicle cholesterol controls fusion pore and is relevant for pathophysiology of LSD.
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Affiliation(s)
- Boštjan Rituper
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Alenka Guček
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Marjeta Lisjak
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Urszula Gorska
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Aleksandra Šakanović
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Saša Trkov Bobnar
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Eva Lasič
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Mićo Božić
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia
| | - Prabhodh S Abbineni
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109-5632, United States of America
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Marko Kreft
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Alexei Verkhratsky
- Celica Biomedical, 1000, Ljubljana, Slovenia; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, United Kingdom; Achucarro Center for Neuroscience, IKERBASQUE, 48011 Bilbao, Spain
| | - Frances M Platt
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, United Kingdom
| | - Gregor Anderluh
- Laboratory for Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Bojan Božič
- Institute of Biophysics, Faculty of Medicine, University of Ljubljana, Slovenia
| | - Jens R Coorssen
- Department of Health Sciences, Faculty of Applied Health Sciences and Department of Biological Sciences, Faculty of Mathematics & Science, Brock University, St Catherine's, Ontario, Canada
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Faculty of Medicine, Ljubljana, Slovenia; Celica Biomedical, 1000, Ljubljana, Slovenia.
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Lasič E, Trkov Bobnar S, Wilhelmsson U, Pablo Y, Pekny M, Zorec R, Stenovec M. Nestin affects fusion pore dynamics in mouse astrocytes. Acta Physiol (Oxf) 2020; 228:e13399. [PMID: 31597221 DOI: 10.1111/apha.13399] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2019] [Revised: 09/17/2019] [Accepted: 09/30/2019] [Indexed: 12/15/2022]
Abstract
AIM Astrocytes play a homeostatic role in the central nervous system and influence numerous aspects of neurophysiology via intracellular trafficking of vesicles. Intermediate filaments (IFs), also known as nanofilaments, regulate a number of cellular processes including organelle trafficking and adult hippocampal neurogenesis. We have recently demonstrated that the IF protein nestin, a marker of neural stem cells and immature and reactive astrocytes, is also expressed in some astrocytes in the unchallenged hippocampus and regulates neurogenesis through Notch signalling from astrocytes to neural stem cells, possibly via altered trafficking of vesicles containing the Notch ligand Jagged-1. METHODS We thus investigated whether nestin affects vesicle dynamics in astrocytes by examining single vesicle interactions with the plasmalemma and vesicle trafficking with high-resolution cell-attached membrane capacitance measurements and confocal microscopy. We used cell cultures of astrocytes from nestin-deficient (Nes-/- ) and wild-type (wt) mice, and fluorescent dextran and Fluo-2 to examine vesicle mobility and intracellular Ca2+ concentration respectively. RESULTS Nes-/- astrocytes exhibited altered sizes of vesicles undergoing full fission and transient fusion, altered vesicle fusion pore geometry and kinetics, decreased spontaneous vesicle mobility and altered ATP-evoked mobility. Purinergic stimulation evoked Ca2+ signalling that was slightly attenuated in Nes-/- astrocytes, which exhibited more oscillatory Ca2+ responses than wt astrocytes. CONCLUSION These results demonstrate at the single vesicle level that nestin regulates vesicle interactions with the plasmalemma and vesicle trafficking, indicating its potential role in astrocyte vesicle-based communication.
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Affiliation(s)
- Eva Lasič
- Laboratory of Neuroendocrinology‐Molecular Cell Physiology Institute of Pathophysiology Faculty of Medicine University of Ljubljana Ljubljana Slovenia
| | - Saša Trkov Bobnar
- Laboratory of Neuroendocrinology‐Molecular Cell Physiology Institute of Pathophysiology Faculty of Medicine University of Ljubljana Ljubljana Slovenia
- Celica Biomedical Ljubljana Slovenia
| | - Ulrika Wilhelmsson
- Laboratory of Astrocyte Biology and CNS Regeneration Center for Brain Repair Department of Clinical Neuroscience Institute of Neuroscience and Physiology Sahlgrenska Academy at the University of Gothenburg Gothenburg Sweden
| | - Yolanda Pablo
- Laboratory of Astrocyte Biology and CNS Regeneration Center for Brain Repair Department of Clinical Neuroscience Institute of Neuroscience and Physiology Sahlgrenska Academy at the University of Gothenburg Gothenburg Sweden
| | - Milos Pekny
- Laboratory of Astrocyte Biology and CNS Regeneration Center for Brain Repair Department of Clinical Neuroscience Institute of Neuroscience and Physiology Sahlgrenska Academy at the University of Gothenburg Gothenburg Sweden
- Florey Institute of Neuroscience and Mental Health Parkville Vic. Australia
- University of Newcastle Newcastle NSW Australia
| | - Robert Zorec
- Laboratory of Neuroendocrinology‐Molecular Cell Physiology Institute of Pathophysiology Faculty of Medicine University of Ljubljana Ljubljana Slovenia
- Celica Biomedical Ljubljana Slovenia
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology‐Molecular Cell Physiology Institute of Pathophysiology Faculty of Medicine University of Ljubljana Ljubljana Slovenia
- Celica Biomedical Ljubljana Slovenia
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5
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Gimenez-Molina Y, García-Martínez V, Villanueva J, Davletov B, Gutiérrez LM. Multiple sclerosis drug FTY-720 toxicity is mediated by the heterotypic fusion of organelles in neuroendocrine cells. Sci Rep 2019; 9:18471. [PMID: 31804600 PMCID: PMC6895052 DOI: 10.1038/s41598-019-55106-w] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 11/24/2019] [Indexed: 12/29/2022] Open
Abstract
FTY-720 (Fingolimod) was one of the first compounds authorized for the treatment of multiple sclerosis. Among its other activities, this sphingosine analogue enhances exocytosis in neuroendocrine chromaffin cells, altering the quantal release of catecholamines. Surprisingly, the size of chromaffin granules is reduced within few minutes of treatment, a process that is paralleled by the homotypic fusion of granules and their heterotypic fusion with mitochondria, as witnessed by dynamic confocal and TIRF microscopy. Electron microscopy studies support these observations, revealing the fusion of several vesicles with individual mitochondria to form large, round mixed organelles. This cross-fusion is SNARE-dependent, being partially prevented by the expression of an inactive form of SNAP-25. Fused mitochondria exhibit an altered redox potential, which dramatically enhances cell death. Therefore, the cross-fusion of intracellular organelles appears to be a new mechanism to be borne in mind when considering the effect of FTY-720 on the survival of neuroendocrine cells.
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Affiliation(s)
- Yolanda Gimenez-Molina
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Sant Joan d'Alacant, Alicante, 03550, Spain
| | - Virginia García-Martínez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Sant Joan d'Alacant, Alicante, 03550, Spain
| | - José Villanueva
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Sant Joan d'Alacant, Alicante, 03550, Spain
| | - Bazbek Davletov
- Department of Biomedical Science, University of Sheffield, Firth Court, Western Bank, Sheffield, S10 2TN, UK
| | - Luis M Gutiérrez
- Instituto de Neurociencias de Alicante, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Sant Joan d'Alacant, Alicante, 03550, Spain.
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Astrocyte Specific Remodeling of Plasmalemmal Cholesterol Composition by Ketamine Indicates a New Mechanism of Antidepressant Action. Sci Rep 2019; 9:10957. [PMID: 31358895 PMCID: PMC6662760 DOI: 10.1038/s41598-019-47459-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 07/15/2019] [Indexed: 12/20/2022] Open
Abstract
Ketamine is an antidepressant with rapid therapeutic onset and long-lasting effect, although the underlying mechanism(s) remain unknown. Using FRET-based nanosensors we found that ketamine increases [cAMP]i in astrocytes. Membrane capacitance recordings, however, reveal fundamentally distinct mechanisms of effects of ketamine and [cAMP]i on vesicular secretion: a rise in [cAMP]i facilitated, whereas ketamine inhibited exocytosis. By directly monitoring cholesterol-rich membrane domains with a fluorescently tagged cholesterol-specific membrane binding domain (D4) of toxin perfringolysin O, we demonstrated that ketamine induced cholesterol redistribution in the plasmalemma in astrocytes, but neither in fibroblasts nor in PC 12 cells. This novel mechanism posits that ketamine affects density and distribution of cholesterol in the astrocytic plasmalemma, consequently modulating a host of processes that may contribute to ketamine's rapid antidepressant action.
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7
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Mishra SK, Stephenson DJ, Chalfant CE, Brown RE. Upregulation of human glycolipid transfer protein (GLTP) induces necroptosis in colon carcinoma cells. Biochim Biophys Acta Mol Cell Biol Lipids 2019; 1864:158-167. [PMID: 30472325 PMCID: PMC6448591 DOI: 10.1016/j.bbalip.2018.11.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 11/03/2018] [Accepted: 11/10/2018] [Indexed: 02/06/2023]
Abstract
Human GLTP on chromosome 12 (locus 12q24.11) encodes a 24 kD amphitropic lipid transfer protein (GLTP) that mediates glycosphingolipid (GSL) intermembrane trafficking and regulates GSL homeostatic levels within cells. Herein, we provide evidence that GLTP overexpression inhibits the growth of human colon carcinoma cells (HT-29; HCT-116), but spares normal colonic cells (CCD-18Co). Mechanistic studies reveal that GLTP overexpression arrested the cell cycle at the G1/S checkpoint via upregulation of cyclin-dependent kinase inhibitor-1B (Kip1/p27) and cyclin-dependent kinase inhibitor 1A (Cip1/p21) at the protein and mRNA levels, and downregulation of cyclin-dependent kinase-2 (CDK2), cyclin-dependent kinase-4 (CDK4), cyclin E and cyclin D1 protein levels. Assessment of the biological fate of HCT-116 cells overexpressing GLTP indicated no increase in cell death suggesting induction of quiescence. However, HT-29 cells overexpressing GLTP underwent cell death by necroptosis as revealed by phosphorylation of human mixed lineage kinase domain-like protein (pMLKL) via receptor-interacting protein kinase-3 (RIPK-3), elevated cytosolic calcium, and plasma membrane permeabilization by pMLKL oligomerization. Overexpression of W96A-GLTP, an ablated GSL binding site mutant, failed to arrest the cell cycle or induce necroptosis. Sphingolipid assessment (ceramide, monohexosylceramide, sphingomyelin, ceramide-1-phosphate, sphingosine, and sphingosine-1-phosphate) of HT-29 cells overexpressing GLTP revealed large decreases (>5-fold) in sphingosine-1-phosphate with minimal change in 16:0-ceramide, tipping the 'sphingolipid rheostat' (S1P/16:0-Cer ratio) towards cell death. Depletion of RIPK-3 or MLKL abrogated necroptosis induced by GLTP overexpression. Our findings establish GLTP upregulation as a previously unknown suppressor of human colon carcinoma HT-29 cells via interference with cell cycle progression and induction of necroptosis.
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Affiliation(s)
| | - Daniel J Stephenson
- Department of Biochemistry and Molecular Biology, Virginia Commonwealth University Medical Center, Richmond, VA 23298-0614, USA; Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA
| | - Charles E Chalfant
- Department of Cell Biology, Microbiology and Molecular Biology, University of South Florida, Tampa, FL 33620, USA; Research Service, James A. Haley Veterans Hospital, Tampa, FL 33612, USA; The Moffitt Cancer Center, Tampa, FL 33620, USA
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Fingolimod Suppresses the Proinflammatory Status of Interferon-γ-Activated Cultured Rat Astrocytes. Mol Neurobiol 2019; 56:5971-5986. [PMID: 30701416 DOI: 10.1007/s12035-019-1481-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 01/10/2019] [Indexed: 12/14/2022]
Abstract
Astroglia, the primary homeostatic cells of the central nervous system, play an important role in neuroinflammation. They act as facultative immunocompetent antigen-presenting cells (APCs), expressing major histocompatibility complex (MHC) class II antigens upon activation with interferon (IFN)-γ and possibly other proinflammatory cytokines that are upregulated in disease states, including multiple sclerosis (MS). We characterized the anti-inflammatory effects of fingolimod (FTY720), an established drug for MS, and its phosphorylated metabolite (FTY720-P) in IFN-γ-activated cultured rat astrocytes. The expression of MHC class II compartments, β2 adrenergic receptor (ADR-β2), and nuclear factor kappa-light-chain enhancer of activated B cells subunit p65 (NF-κB p65) was quantified in immunofluorescence images acquired by laser scanning confocal microscopy. In addition, MHC class II-enriched endocytotic vesicles were labeled by fluorescent dextran and their mobility analyzed in astrocytes subjected to different treatments. FTY720 and FTY720-P treatment significantly reduced the number of IFN-γ-induced MHC class II compartments and substantially increased ADR-β2 expression, which is otherwise small or absent in astrocytes in MS. These effects could be partially attributed to the observed decrease in NF-κB p65 expression, because the NF-κB signaling cascade is activated in inflammatory processes. We also found attenuated trafficking and secretion from dextran-labeled endo-/lysosomes that may hinder efficient delivery of MHC class II molecules to the plasma membrane. Our data suggest that FTY720 and FTY720-P at submicromolar concentrations mediate anti-inflammatory effects on astrocytes by suppressing their action as APCs, which may further downregulate the inflammatory process in the brain, constituting the therapeutic effect of fingolimod in MS.
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Garcia-Martinez V, Gimenez-Molina Y, Villanueva J, Darios FD, Davletov B, Gutiérrez LM. Emerging evidence for the modulation of exocytosis by signalling lipids. FEBS Lett 2018; 592:3493-3503. [PMID: 29962039 PMCID: PMC6282582 DOI: 10.1002/1873-3468.13178] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2018] [Revised: 06/01/2018] [Accepted: 06/27/2018] [Indexed: 01/22/2023]
Abstract
Membrane fusion is a key event in exocytosis of neurotransmitters and hormones stored in intracellular vesicles. In this process, soluble N‐ethylmaleimide sensitive factor attachment protein receptor (SNARE) proteins are essential components of the exocytotic molecular machinery, while lipids have been seen traditionally as structural elements. However, the so‐called signalling lipids, such as sphingosine and arachidonic acid, interact with SNAREs and directly modulate the frequency and mode of fusion events. Interestingly, recent work has proved that the sphingosine analogue FTY‐720, used in the treatment of multiple sclerosis, mimics the effects of signalling lipids. In the present Review, we discuss recent investigations suggesting that endogenous signalling lipids and synthetic analogues can modulate important physiological aspects of secretion, such as quantal release, vesicle recruitment into active sites, vesicle transport and even organelle fusion in the cytosol. Therefore, these compounds are far from being merely structural components of cellular membranes.
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Affiliation(s)
- Virginia Garcia-Martinez
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández de Elche, Sant Joan d'Alacant, Alicante, Spain
| | - Yolanda Gimenez-Molina
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández de Elche, Sant Joan d'Alacant, Alicante, Spain
| | - José Villanueva
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández de Elche, Sant Joan d'Alacant, Alicante, Spain
| | - Frederic D Darios
- Inserm, U1127, CNRS, UMR 7225, Institut du Cerveau et de la Moelle épinière, ICM, Sorbonne Université, Paris, France
| | - Bazbek Davletov
- Department of Biomedical Sciences, University of Sheffield, UK
| | - Luis M Gutiérrez
- Instituto de Neurociencias de Alicante, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández de Elche, Sant Joan d'Alacant, Alicante, Spain
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10
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Stenovec M, Trkov Bobnar S, Smolič T, Kreft M, Parpura V, Zorec R. Presenilin PS1∆E9 disrupts mobility of secretory organelles in rat astrocytes. Acta Physiol (Oxf) 2018; 223:e13046. [PMID: 29392878 DOI: 10.1111/apha.13046] [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: 11/09/2017] [Revised: 01/17/2018] [Accepted: 01/25/2018] [Indexed: 12/14/2022]
Abstract
AIM Alzheimer's disease (AD) is largely considered a neuron-derived insult, but also involves failure of astroglia. A recent study indicated that mutated presenilin 1 (PS1M146V), a putative endoplasmic reticulum (ER) Ca2+ channel with decreased Ca2+ conductance, impairs the traffic of astroglial peptidergic vesicles. Whether other pathogenically relevant PS1 mutants, such as PS1ΔE9, which code for ER channel with putative increased Ca2+ conductance, similarly affect vesicle traffic, is unknown. METHODS Here, we cotransfected rat astrocytes with plasmids encoding mutant PS1ΔE9 and atrial natriuretic peptide or vesicular glutamate transporter 1 tagged with fluorescent proteins (pANP.emd or pVGLUT1-EGFP respectively), to microscopically examine whether alterations in vesicle mobility and Ca2+ -regulated release of gliosignalling molecules manifest as a general vesicle-based defect; control cells were transfected to co-express exogenous or native wild-type PS1 and pANP.emd or pVGLUT1-EGFP. The vesicle mobility was analysed at rest and after ATP stimulation that increased intracellular calcium activity. RESULTS In PS1ΔE9 astrocytes, spontaneous mobility of both vesicle types was reduced (P < .001) when compared to controls. Post-stimulatory recovery of fast vesicle mobility was hampered in PS1ΔE9 astrocytes. The ATP-evoked peptide release was less efficient in PS1ΔE9 astrocytes than in the controls (P < .05), as was the pre-stimulatory mobility of these vesicles. CONCLUSION Although the PS1 mutants PS1M146V and PS1ΔE9 differently affect ER Ca2+ conductance, our results revealed a common, vesicle-type indiscriminate trafficking defect in PS1ΔE9 astrocytes, indicating that reduced secretory vesicle-based signalling is a general deficit in AD astrocytes.
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Affiliation(s)
- M. Stenovec
- Celica BIOMEDICAL; Ljubljana Slovenia
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
| | - S. Trkov Bobnar
- Celica BIOMEDICAL; Ljubljana Slovenia
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
| | - T. Smolič
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
| | - M. Kreft
- Celica BIOMEDICAL; Ljubljana Slovenia
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
- Biotechnical Faculty; CPAE; Department of Biology; University of Ljubljana; Ljubljana Slovenia
| | - V. Parpura
- Department of Neurobiology; Civitan International Research Center and Center for Glial Biology in Medicine; Evelyn F. McKnight Brain Institute; Atomic Force Microscopy & Nanotechnology Laboratories; University of Alabama at Birmingham; Birmingham AL USA
| | - R. Zorec
- Celica BIOMEDICAL; Ljubljana Slovenia
- Faculty of Medicine; Laboratory of Neuroendocrinology-Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
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11
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Slow Release of HIV-1 Protein Nef from Vesicle-like Structures Is Inhibited by Cytosolic Calcium Elevation in Single Human Microglia. Mol Neurobiol 2018; 56:102-118. [DOI: 10.1007/s12035-018-1072-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 04/09/2018] [Indexed: 12/14/2022]
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12
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Darios FD, Jorgacevski J, Flašker A, Zorec R, García-Martinez V, Villanueva J, Gutiérrez LM, Leese C, Bal M, Nosyreva E, Kavalali ET, Davletov B. Sphingomimetic multiple sclerosis drug FTY720 activates vesicular synaptobrevin and augments neuroendocrine secretion. Sci Rep 2017; 7:5958. [PMID: 28729700 PMCID: PMC5519734 DOI: 10.1038/s41598-017-05948-z] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2016] [Accepted: 06/07/2017] [Indexed: 01/22/2023] Open
Abstract
Neurotransmission and secretion of hormones involve a sequence of protein/lipid interactions with lipid turnover impacting on vesicle trafficking and ultimately fusion of secretory vesicles with the plasma membrane. We previously demonstrated that sphingosine, a sphingolipid metabolite, promotes formation of the SNARE complex required for membrane fusion and also increases the rate of exocytosis in isolated nerve terminals, neuromuscular junctions, neuroendocrine cells and in hippocampal neurons. Recently a fungi-derived sphingosine homologue, FTY720, has been approved for treatment of multiple sclerosis. In its non-phosphorylated form FTY720 accumulates in the central nervous system, reaching high levels which could affect neuronal function. Considering close structural similarity of sphingosine and FTY720 we investigated whether FTY720 has an effect on regulated exocytosis. Our data demonstrate that FTY720 can activate vesicular synaptobrevin for SNARE complex formation and enhance exocytosis in neuroendocrine cells and neurons.
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Affiliation(s)
- Frederic D Darios
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK.,Hôpital Pitié Salpêtrière, ICM, 75013, Paris, France
| | - Jernej Jorgacevski
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia.,Celica Biomedical, 1000, Ljubljana, Slovenia
| | - Ajda Flašker
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Faculty of Medicine, University of Ljubljana, 1000, Ljubljana, Slovenia.,Celica Biomedical, 1000, Ljubljana, Slovenia
| | | | - José Villanueva
- Institute of Neurosciences, CSIC-Miguel Hernandez University, 03550, Alicante, Spain
| | - Luis M Gutiérrez
- Institute of Neurosciences, CSIC-Miguel Hernandez University, 03550, Alicante, Spain
| | - Charlotte Leese
- Department of Biomedical Sciences, University of Sheffield, Sheffield, S10 2TN, UK
| | - Manjot Bal
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Elena Nosyreva
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Ege T Kavalali
- Department of Neuroscience, UT Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Bazbek Davletov
- MRC Laboratory of Molecular Biology, Cambridge, CB2 0QH, UK. .,Department of Biomedical Sciences, University of Sheffield, Sheffield, S10 2TN, UK.
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13
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Astrocytic Pathological Calcium Homeostasis and Impaired Vesicle Trafficking in Neurodegeneration. Int J Mol Sci 2017; 18:ijms18020358. [PMID: 28208745 PMCID: PMC5343893 DOI: 10.3390/ijms18020358] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2016] [Revised: 01/30/2017] [Accepted: 01/31/2017] [Indexed: 02/08/2023] Open
Abstract
Although the central nervous system (CNS) consists of highly heterogeneous populations of neurones and glial cells, clustered into diverse anatomical regions with specific functions, there are some conditions, including alertness, awareness and attention that require simultaneous, coordinated and spatially homogeneous activity within a large area of the brain. During such events, the brain, representing only about two percent of body mass, but consuming one fifth of body glucose at rest, needs additional energy to be produced. How simultaneous energy procurement in a relatively extended area of the brain takes place is poorly understood. This mechanism is likely to be impaired in neurodegeneration, for example in Alzheimer’s disease, the hallmark of which is brain hypometabolism. Astrocytes, the main neural cell type producing and storing glycogen, a form of energy in the brain, also hold the key to metabolic and homeostatic support in the central nervous system and are impaired in neurodegeneration, contributing to the slow decline of excitation-energy coupling in the brain. Many mechanisms are affected, including cell-to-cell signalling. An important question is how changes in cellular signalling, a process taking place in a rather short time domain, contribute to the neurodegeneration that develops over decades. In this review we focus initially on the slow dynamics of Alzheimer’s disease, and on the activity of locus coeruleus, a brainstem nucleus involved in arousal. Subsequently, we overview much faster processes of vesicle traffic and cytosolic calcium dynamics, both of which shape the signalling landscape of astrocyte-neurone communication in health and neurodegeneration.
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14
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Lasič E, Galland F, Vardjan N, Šribar J, Križaj I, Leite MC, Zorec R, Stenovec M. Time-dependent uptake and trafficking of vesicles capturing extracellular S100B in cultured rat astrocytes. J Neurochem 2016; 139:309-323. [PMID: 27488079 DOI: 10.1111/jnc.13754] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2016] [Revised: 07/21/2016] [Accepted: 07/26/2016] [Indexed: 01/16/2023]
Abstract
Astrocytes, the most heterogeneous glial cells in the central nervous system, contribute to brain homeostasis, by regulating a myriad of functions, including the clearance of extracellular debris. When cells are damaged, cytoplasmic proteins may exit into the extracellular space. One such protein is S100B, which may exert toxic effects on neighboring cells unless it is removed from the extracellular space, but the mechanisms of this clearance are poorly understood. By using time-lapse confocal microscopy and fluorescently labeled S100B (S100B-Alexa488 ) and fluorescent dextran (Dextran546 ), a fluid phase uptake marker, we examined the uptake of fluorescently labeled S100B-Alexa488 from extracellular space and monitored trafficking of vesicles that internalized S100B-Alexa488 . Initially, S100B-Alexa488 and Dextran546 internalized with distinct rates into different endocytotic vesicles; S100B-Alexa488 internalized into smaller vesicles than Dextran546 . At a later stage, S100B-Alexa488 -positive vesicles substantially co-localized with Dextran546 -positive endolysosomes and with acidic LysoTracker-positive vesicles. Cell treatment with anti-receptor for advanced glycation end products (RAGE) antibody, which binds to RAGE, a 'scavenger receptor', partially inhibited uptake of S100B-Alexa488 , but not of Dextran546 . The dynamin inhibitor dynole 34-2 inhibited internalization of both fluorescent probes. Directional mobility of S100B-Alexa488 -positive vesicles increased over time and was inhibited by ATP stimulation, an agent that increases cytosolic free calcium concentration ([Ca2+ ]i ). We conclude that astrocytes exhibit RAGE- and dynamin-dependent vesicular mechanism to efficiently remove S100B from the extracellular space. If a similar process occurs in vivo, astroglia may mitigate the toxic effects of extracellular S100B by this process under pathophysiologic conditions. This study reveals the vesicular clearance mechanism of extracellular S100B in astrocytes. Initially, fluorescent S100B internalizes into smaller endocytotic vesicles than dextran molecules. At a later stage, both probes co-localize within endolysosomes. S100B internalization is both dynamin- and RAGE-dependent, whereas dextran internalization is dependent on dynamin. Vesicle internalization likely mitigates the toxic effects of extracellular S100B and other waste products.
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Affiliation(s)
- Eva Lasič
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Fabiana Galland
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Nina Vardjan
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Celica Biomedical, Ljubljana, Slovenia
| | - Jernej Šribar
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia
| | - Igor Križaj
- Department of Molecular and Biomedical Sciences, Jožef Stefan Institute, Ljubljana, Slovenia.,Faculty of Chemistry and Chemical Technology, University of Ljubljana, Ljubljana, Slovenia
| | - Marina Concli Leite
- Departamento de Bioquímica, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil
| | - Robert Zorec
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia. .,Celica Biomedical, Ljubljana, Slovenia.
| | - Matjaž Stenovec
- Laboratory of Neuroendocrinology - Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia. .,Celica Biomedical, Ljubljana, Slovenia.
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15
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Blumenfeld S, Staun-Ram E, Miller A. Fingolimod therapy modulates circulating B cell composition, increases B regulatory subsets and production of IL-10 and TGFβ in patients with Multiple Sclerosis. J Autoimmun 2016; 70:40-51. [PMID: 27055778 DOI: 10.1016/j.jaut.2016.03.012] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 03/20/2016] [Accepted: 03/23/2016] [Indexed: 01/26/2023]
Abstract
Fingolimod, an oral therapeutic agent approved for patients with relapsing-remitting Multiple Sclerosis (MS), has been shown to prevent lymphocyte egress from secondary lymphoid tissues; however the specific drug effect on B cells in fingolimod-treated patients remains to be fully elucidated. We present here a comprehensive analysis on the proportions of B cell subsets in the periphery, and the levels of activation, functional surface markers and cytokine profile of B cells in MS patients, following initiation of fingolimod therapy, using flow cytometry and cytokine bead array. Fingolimod therapy increased the ratio of naïve to memory cells, elevated the percentage of plasma cells and highly increased the proportion of transitional B cells as well as additional regulatory subsets, including: IL10(+), CD25(+) and CD5(+) B cells. The percentage of activated CD69(+) cells was highly elevated in the remaining circulating B cells, which produced increased levels of IL10, TGFβ, IL6, IL4, LTα, TNFα and IFNγ cytokines, with an overall increased ratio of TGFβ to pro-inflammatory cytokines. Furthermore, fingolimod therapy reduced ICAM-1(+) cells, suggesting a possible reduction in antigen-presenting capacity. Phosphorylated-fingolimod was shown in vitro to reduce S1PR1 RNA and protein, to slightly increase viability and to activate anti-apoptotic Bcl2 in transformed B cells of patients with MS. In conclusion, fingolimod therapy modulates significantly the composition of circulating B cells, promoting regulatory subsets and an anti-inflammatory cytokine repertoire.
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Affiliation(s)
- Shiri Blumenfeld
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Elsebeth Staun-Ram
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel
| | - Ariel Miller
- Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa, Israel; Neuroimmunology Unit & Multiple Sclerosis Center, Carmel Medical Center, Haifa, Israel.
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16
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Benaim G, Pimentel AA, Felibertt P, Mayora A, Colman L, Sojo F, Rojas H, De Sanctis JB. Sphingosine inhibits the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA) activity. Biochem Biophys Res Commun 2016; 473:572-7. [PMID: 27033604 DOI: 10.1016/j.bbrc.2016.03.123] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2016] [Accepted: 03/26/2016] [Indexed: 10/22/2022]
Abstract
The increase in the intracellular Ca(2+) concentration ([Ca(2+)]i) is the key variable for many different processes, ranging from regulation of cell proliferation to apoptosis. In this work we demonstrated that the sphingolipid sphingosine (Sph) increases the [Ca(2+)]i by inhibiting the sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA), in a similar manner to thapsigargin (Tg), a specific inhibitor of this Ca(2+) pump. The results showed that addition of sphingosine produced a release of Ca(2+) from the endoplasmic reticulum followed by a Ca(2+) entrance from the outside mileu. The results presented in this work support that this sphingolipid could control the activity of the SERCA, and hence sphingosine may participate in the regulation of [Ca(2+)]I in mammalian cells.
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Affiliation(s)
- Gustavo Benaim
- Instituto de Estudios Avanzados (IDEA), Caracas, Venezuela; Instituto de Biología Experimental, Facultad de Ciencias, Universidad Central de Venezuela (UCV), Caracas, Venezuela.
| | - Adriana A Pimentel
- Facultad de Farmacia, Universidad Central de Venezuela (UCV), Caracas, Venezuela.
| | - Pimali Felibertt
- Facultad de Ciencias, Universidad de Carabobo, Valencia, Venezuela
| | - Adriana Mayora
- Instituto de Biología Experimental, Facultad de Ciencias, Universidad Central de Venezuela (UCV), Caracas, Venezuela
| | - Laura Colman
- Instituto Pasteur de Montevideo, Montevideo, Uruguay
| | - Felipe Sojo
- Instituto de Biología Experimental, Facultad de Ciencias, Universidad Central de Venezuela (UCV), Caracas, Venezuela
| | - Héctor Rojas
- Instituto de Inmunología, Universidad Central de Venezuela (UCV), Caracas, Venezuela; Centro de Biofísica y Bioquímica, Instituto Venezolano de Investigaciones Científicas (IVIC), Caracas, Venezuela
| | - Juan B De Sanctis
- Instituto de Inmunología, Universidad Central de Venezuela (UCV), Caracas, Venezuela
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17
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Stenovec M, Lasič E, Božić M, Bobnar ST, Stout RF, Grubišić V, Parpura V, Zorec R. Ketamine Inhibits ATP-Evoked Exocytotic Release of Brain-Derived Neurotrophic Factor from Vesicles in Cultured Rat Astrocytes. Mol Neurobiol 2015; 53:6882-6896. [PMID: 26660497 DOI: 10.1007/s12035-015-9562-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 11/29/2015] [Indexed: 02/07/2023]
Abstract
In the brain, astrocytes signal to neighboring cells via regulated exocytotic release of gliosignaling molecules, such as brain-derived neurotrophic factor (BDNF). Recent studies uncovered a role of ketamine, an anesthetic and antidepressant, in the regulation of BDNF expression and in the disruption of astrocytic Ca2+ signaling, but it is unclear whether it affects astroglial BDNF release. We investigated whether ketamine affects ATP-evoked Ca2+ signaling and exocytotic release of BDNF at the single-vesicle level in cultured rat astrocytes. Cells were transfected with a plasmid encoding preproBDNF tagged with the pH-sensitive fluorescent protein superecliptic pHluorin, (BDNF-pHse) to load vesicles and measure the release of BDNF-pHse when the exocytotic fusion pore opens and alkalinizes the luminal pH. In addition, cell-attached membrane capacitance changes were recorded to monitor unitary vesicle interaction with the plasma membrane. Intracellular Ca2+ activity was monitored with Fluo-4 and confocal microscopy, which was also used to immunocytochemically characterize BDNF-pHse-laden vesicles. As revealed by double-fluorescent micrographs, BDNF-pHse localized to vesicles positive for the soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptor (SNARE) proteins, vesicle-associated membrane protein 2 (VAMP2), VAMP3, and synaptotagmin IV. Ketamine treatment decreased the number of ATP-evoked BDNF-pHse fusion/secretion events (P < 0.05), the frequency of ATP-evoked transient (P < 0.001) and full-fusion exocytotic (P < 0.05) events, along with a reduction in the ATP-evoked increase in intracellular Ca2+ activity in astrocytes by ~70 % (P < 0.001). The results show that ketamine treatment suppresses ATP-triggered vesicle fusion and BDNF secretion by increasing the probability of a narrow fusion pore open state and/or by reducing astrocytic Ca2+ excitability.
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Affiliation(s)
- Matjaž Stenovec
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | - Eva Lasič
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | - Mićo Božić
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | - Saša Trkov Bobnar
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia
| | - Randy F Stout
- Department of Neurobiology, Civitan International Research Center and Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, Atomic Force Microscopy and Nanotechnology Laboratories, University of Alabama at Birmingham, 1719 6th Avenue South, CIRC 429, Birmingham, AL, 35294, USA
- The Dominick P. Purpura Department of Neuroscience, Rose F. Kennedy Center, Albert Einstein College of Medicine, Bronx, NY, 10461, USA
| | - Vladimir Grubišić
- Department of Neurobiology, Civitan International Research Center and Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, Atomic Force Microscopy and Nanotechnology Laboratories, University of Alabama at Birmingham, 1719 6th Avenue South, CIRC 429, Birmingham, AL, 35294, USA
- Department of Physiology, Neuroscience Program, Michigan State University, East Lansing, MI, USA
| | - Vladimir Parpura
- Department of Neurobiology, Civitan International Research Center and Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, Atomic Force Microscopy and Nanotechnology Laboratories, University of Alabama at Birmingham, 1719 6th Avenue South, CIRC 429, Birmingham, AL, 35294, USA
| | - Robert Zorec
- Celica Biomedical, Tehnološki park 24, 1000, Ljubljana, Slovenia.
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia.
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18
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Stenovec M, Trkov S, Lasič E, Terzieva S, Kreft M, Rodríguez Arellano JJ, Parpura V, Verkhratsky A, Zorec R. Expression of familial Alzheimer disease presenilin 1 gene attenuates vesicle traffic and reduces peptide secretion in cultured astrocytes devoid of pathologic tissue environment. Glia 2015; 64:317-29. [PMID: 26462451 DOI: 10.1002/glia.22931] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2015] [Revised: 09/22/2015] [Accepted: 09/22/2015] [Indexed: 02/06/2023]
Abstract
In the brain, astrocytes provide metabolic and trophic support to neurones. Failure in executing astroglial homeostatic functions may contribute to the initiation and propagation of diseases, including Alzheimer disease (AD), characterized by a progressive loss of neurones over years. Here, we examined whether astrocytes from a mice model of AD isolated in the presymptomatic phase of the disease exhibit alterations in vesicle traffic, vesicular peptide release and purinergic calcium signaling. In cultured astrocytes isolated from a newborn wild-type (wt) and 3xTg-AD mouse, secretory vesicles and acidic endosomes/lysosomes were labeled by transfection with plasmid encoding atrial natriuretic peptide tagged with mutant green fluorescent protein (ANP.emd) and by LysoTracker, respectively. The intracellular Ca(2+) concentration ([Ca(2+)]i) was monitored with Fluo-2 and visualized by confocal microscopy. In comparison with controls, spontaneous mobility of ANP- and LysoTracker-labeled vesicles was diminished in 3xTg-AD astrocytes; the track length (TL), maximal displacement (MD) and directionality index (DI) were all reduced in peptidergic vesicles and in endosomes/lysosomes (P < 0.001), as was the ATP-evoked attenuation of vesicle mobility. Similar impairment of peptidergic vesicle trafficking was observed in wt rat astrocytes transfected to express mutated presenilin 1 (PS1M146V). The ATP-evoked ANP discharge from single vesicles was less efficient in 3xTg-AD and PS1M146V-expressing astrocytes than in respective wt controls (P < 0.05). Purinergic stimulation evoked biphasic and oscillatory [Ca(2+)]i responses; the latter were less frequent (P < 0.001) in 3xTg-AD astrocytes. Expression of PS1M146V in astrocytes impairs vesicle dynamics and reduces evoked secretion of the signaling molecule ANP; both may contribute to the development of AD.
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Affiliation(s)
- Matjaž Stenovec
- Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Saša Trkov
- Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Eva Lasič
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Slavica Terzieva
- Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.,Department of Neuroscience, Faculty of Medicine and Odontology, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain
| | - Marko Kreft
- Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Department of Biology, University of Ljubljana, Biotechnical Faculty, CPAE, Ljubljana, Slovenia
| | - José Julio Rodríguez Arellano
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.,Department of Neuroscience, Faculty of Medicine and Odontology, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain
| | - Vladimir Parpura
- Department of Neurobiology, Civitan International Research Center and Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, Atomic Force Microscopy & Nanotechnology Laboratories, University of Alabama at Birmingham, Birmingham, Alabama
| | - Alexei Verkhratsky
- Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia.,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.,Department of Neuroscience, Faculty of Medicine and Odontology, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.,Faculty of Life Sciences, University of Manchester, Manchester, United Kingdom
| | - Robert Zorec
- Celica BIOMEDICAL, Ljubljana, Slovenia.,Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
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19
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Upadhyay RK. Emerging risk biomarkers in cardiovascular diseases and disorders. J Lipids 2015; 2015:971453. [PMID: 25949827 PMCID: PMC4407625 DOI: 10.1155/2015/971453] [Citation(s) in RCA: 158] [Impact Index Per Article: 17.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 02/24/2015] [Accepted: 02/25/2015] [Indexed: 12/16/2022] Open
Abstract
Present review article highlights various cardiovascular risk prediction biomarkers by incorporating both traditional risk factors to be used as diagnostic markers and recent technologically generated diagnostic and therapeutic markers. This paper explains traditional biomarkers such as lipid profile, glucose, and hormone level and physiological biomarkers based on measurement of levels of important biomolecules such as serum ferritin, triglyceride to HDLp (high density lipoproteins) ratio, lipophorin-cholesterol ratio, lipid-lipophorin ratio, LDL cholesterol level, HDLp and apolipoprotein levels, lipophorins and LTPs ratio, sphingolipids, Omega-3 Index, and ST2 level. In addition, immunohistochemical, oxidative stress, inflammatory, anatomical, imaging, genetic, and therapeutic biomarkers have been explained in detail with their investigational specifications. Many of these biomarkers, alone or in combination, can play important role in prediction of risks, its types, and status of morbidity. As emerging risks are found to be affiliated with minor and microlevel factors and its diagnosis at an earlier stage could find CVD, hence, there is an urgent need of new more authentic, appropriate, and reliable diagnostic and therapeutic markers to confirm disease well in time to start the clinical aid to the patients. Present review aims to discuss new emerging biomarkers that could facilitate more authentic and fast diagnosis of CVDs, HF (heart failures), and various lipid abnormalities and disorders in the future.
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Affiliation(s)
- Ravi Kant Upadhyay
- Department of Zoology, DDU Gorakhpur University, Gorakhpur 273009, India
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20
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Voccoli V, Tonazzini I, Signore G, Caleo M, Cecchini M. Role of extracellular calcium and mitochondrial oxygen species in psychosine-induced oligodendrocyte cell death. Cell Death Dis 2014; 5:e1529. [PMID: 25412308 PMCID: PMC4260741 DOI: 10.1038/cddis.2014.483] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/22/2014] [Accepted: 10/06/2014] [Indexed: 02/06/2023]
Abstract
Globoid cell leukodystrophy (GLD) is a metabolic disease caused by mutations in the galactocerebrosidase (GALC) gene. GALC is a lysosomal enzyme whose function is to degrade galacto-lipids, including galactosyl-ceramide and galactosyl-sphingosine (psychosine, PSY). GALC loss of function causes progressive intracellular accumulation of PSY. It is widely held that PSY is the main trigger for the degeneration of myelinating cells and progressive white-matter loss. However, still little is known about the molecular mechanisms by which PSY imparts toxicity. Here, we address the role of calcium dynamics during PSY-induced cell death. Using the human oligodendrocyte cell line MO3.13, we report that cell death by PSY is accompanied by robust cytosolic and mitochondrial calcium (Ca(2+)) elevations, and by mitochondrial reactive oxygen species (ROS) production. Importantly, we demonstrate that the reduction of extracellular calcium content by the chelating agent ethylenediaminetetraacetic acid can decrease intra-mitochondrial ROS production and enhance cell viability. Antioxidant administration also reduces mitochondrial ROS production and cell loss, but this treatment does not synergize with Ca(2+) chelation. Our results disclose novel intracellular pathways involved in PSY-induced death that may be exploited for therapeutic purposes to delay GLD onset and/or slow down its progression.
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Affiliation(s)
- V Voccoli
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - I Tonazzini
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
| | - G Signore
- Center for Nanotechnology Innovation@NEST, Istituto Italiano di Tecnologia, Pisa, Italy
| | - M Caleo
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124 Pisa, Italy
| | - M Cecchini
- NEST, Istituto Nanoscienze-CNR and Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy
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Davletov B. A multiple sclerosis drug sheds light on astrocyte biology. Acta Physiol (Oxf) 2014; 212:8-10. [PMID: 24947320 DOI: 10.1111/apha.12330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Affiliation(s)
- B. Davletov
- Department of Biomedical Science; University of Sheffield; Sheffield UK
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