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Magalhães DM, Mampay M, Sebastião AM, Sheridan GK, Valente CA. Age-related impact of social isolation in mice: Young vs middle-aged. Neurochem Int 2024; 174:105678. [PMID: 38266657 DOI: 10.1016/j.neuint.2024.105678] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2023] [Revised: 01/14/2024] [Accepted: 01/14/2024] [Indexed: 01/26/2024]
Abstract
Social isolation is a chronic mild stressor and a significant risk factor for mental health disorders. Herein we explored the impact of social isolation on depression- and anxiety-like behaviours, as well as spatial memory impairments, in middle-aged male mice compared to post-weaning mice. We aimed to quantify and correlate social isolation-induced behaviour discrepancies with changes in hippocampal glial cell reactivity and pro-inflammatory cytokine levels. Post-weaning and middle-aged C57BL7/J6 male mice were socially isolated for a 3-week period and behavioural tests were performed on the last five days of isolation. We found that 3 weeks of social isolation led to depressive-like behaviour in the forced swim test, anxiety-like behaviour in the open field test, and spatial memory impairment in the Morris water maze paradigm in middle-aged male mice. These behavioural alterations were not observed in male mice after post-weaning social isolation, indicating resilience to isolation-mediated stress. Increased Iba-1 expression and NLRP3 priming were both observed in the hippocampus of socially isolated middle-aged mice, suggesting a role for microglia and NLRP3 pathway in the detrimental effects of social isolation on cognition and behaviour. Young socially isolated mice also demonstrated elevated NLRP3 priming compared to controls, but no differences in Iba-1 levels and no significant changes in behaviour. Ageing-induced microglia activation and enhancement of IL-1β, TNF-α and IL-6 proinflammatory cytokines, known signs of a chronic low-grade inflammatory state, were also detected. Altogether, data suggest that social isolation, in addition to inflammaging, contributes to stress-related cognitive impairment in middle-aged mice.
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Affiliation(s)
- Daniela M Magalhães
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; School of Applied Sciences, University of Brighton, Brighton, UK
| | - Myrthe Mampay
- School of Applied Sciences, University of Brighton, Brighton, UK
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
| | | | - Cláudia A Valente
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal; Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal.
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Magalhães DM, Stewart NA, Mampay M, Rolle SO, Hall CM, Moeendarbary E, Flint MS, Sebastião AM, Valente CA, Dymond MK, Sheridan GK. The sphingosine 1-phosphate analogue, FTY720, modulates the lipidomic signature of the mouse hippocampus. J Neurochem 2024. [PMID: 38339785 DOI: 10.1111/jnc.16073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 12/27/2023] [Accepted: 01/22/2024] [Indexed: 02/12/2024]
Abstract
The small-molecule drug, FTY720 (fingolimod), is a synthetic sphingosine 1-phosphate (S1P) analogue currently used to treat relapsing-remitting multiple sclerosis in both adults and children. FTY720 can cross the blood-brain barrier (BBB) and, over time, accumulate in lipid-rich areas of the central nervous system (CNS) by incorporating into phospholipid membranes. FTY720 has been shown to enhance cell membrane fluidity, which can modulate the functions of glial cells and neuronal populations involved in regulating behaviour. Moreover, direct modulation of S1P receptor-mediated lipid signalling by FTY720 can impact homeostatic CNS physiology, including neurotransmitter release probability, the biophysical properties of synaptic membranes, ion channel and transmembrane receptor kinetics, and synaptic plasticity mechanisms. The aim of this study was to investigate how chronic FTY720 treatment alters the lipid composition of CNS tissue in adolescent mice at a key stage of brain maturation. We focused on the hippocampus, a brain region known to be important for learning, memory, and the processing of sensory and emotional stimuli. Using mass spectrometry-based lipidomics, we discovered that FTY720 increases the fatty acid chain length of hydroxy-phosphatidylcholine (PCOH) lipids in the mouse hippocampus. It also decreases PCOH monounsaturated fatty acids (MUFAs) and increases PCOH polyunsaturated fatty acids (PUFAs). A total of 99 lipid species were up-regulated in the mouse hippocampus following 3 weeks of oral FTY720 exposure, whereas only 3 lipid species were down-regulated. FTY720 also modulated anxiety-like behaviours in young mice but did not affect spatial learning or memory formation. Our study presents a comprehensive overview of the lipid classes and lipid species that are altered in the hippocampus following chronic FTY720 exposure and provides novel insight into cellular and molecular mechanisms that may underlie the therapeutic or adverse effects of FTY720 in the central nervous system.
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Affiliation(s)
- Daniela M Magalhães
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Lisboa, Portugal
- School of Applied Sciences, University of Brighton, Brighton, UK
| | | | - Myrthe Mampay
- School of Applied Sciences, University of Brighton, Brighton, UK
| | - Sara O Rolle
- Green Templeton College, University of Oxford, Oxford, UK
| | - Chloe M Hall
- School of Applied Sciences, University of Brighton, Brighton, UK
- Department of Mechanical Engineering, University College London, London, UK
| | - Emad Moeendarbary
- Department of Mechanical Engineering, University College London, London, UK
- 199 Biotechnologies Ltd, London, UK
| | - Melanie S Flint
- School of Applied Sciences, University of Brighton, Brighton, UK
| | - Ana M Sebastião
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Lisboa, Portugal
| | - Cláudia A Valente
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisboa, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Lisboa, Portugal
| | - Marcus K Dymond
- School of Applied Sciences, University of Brighton, Brighton, UK
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Hall CM, Lasli S, Serwinski B, Djordjevic B, Sheridan GK, Moeendarbary E. Corrigendum: Hippocampus of the APP NL-G-F mouse model of Alzheimer's disease exhibits region-specific tissue softening concomitant with elevated astrogliosis. Front Aging Neurosci 2023; 15:1273549. [PMID: 37700816 PMCID: PMC10494433 DOI: 10.3389/fnagi.2023.1273549] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2023] [Accepted: 08/07/2023] [Indexed: 09/14/2023] Open
Abstract
[This corrects the article DOI: 10.3389/fnagi.2023.1212212.].
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Affiliation(s)
- Chloe M. Hall
- Department of Mechanical Engineering, University College London, London, United Kingdom
- School of Applied Sciences, University of Brighton, Brighton, United Kingdom
| | - Soufian Lasli
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Bianca Serwinski
- Department of Mechanical Engineering, University College London, London, United Kingdom
- 199 Biotechnologies Ltd., London, United Kingdom
- Faculty of Social Sciences, Northeastern University London, London, United Kingdom
| | - Boris Djordjevic
- Department of Mechanical Engineering, University College London, London, United Kingdom
- 199 Biotechnologies Ltd., London, United Kingdom
| | - Graham K. Sheridan
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Emad Moeendarbary
- Department of Mechanical Engineering, University College London, London, United Kingdom
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Whisler J, Shahreza S, Schlegelmilch K, Ege N, Javanmardi Y, Malandrino A, Agrawal A, Fantin A, Serwinski B, Azizgolshani H, Park C, Shone V, Demuren OO, Del Rosario A, Butty VL, Holroyd N, Domart MC, Hooper S, Szita N, Boyer LA, Walker-Samuel S, Djordjevic B, Sheridan GK, Collinson L, Calvo F, Ruhrberg C, Sahai E, Kamm R, Moeendarbary E. Emergent mechanical control of vascular morphogenesis. Sci Adv 2023; 9:eadg9781. [PMID: 37566656 PMCID: PMC10421067 DOI: 10.1126/sciadv.adg9781] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Accepted: 07/13/2023] [Indexed: 08/13/2023]
Abstract
Vascularization is driven by morphogen signals and mechanical cues that coordinately regulate cellular force generation, migration, and shape change to sculpt the developing vascular network. However, it remains unclear whether developing vasculature actively regulates its own mechanical properties to achieve effective vascularization. We engineered tissue constructs containing endothelial cells and fibroblasts to investigate the mechanics of vascularization. Tissue stiffness increases during vascular morphogenesis resulting from emergent interactions between endothelial cells, fibroblasts, and ECM and correlates with enhanced vascular function. Contractile cellular forces are key to emergent tissue stiffening and synergize with ECM mechanical properties to modulate the mechanics of vascularization. Emergent tissue stiffening and vascular function rely on mechanotransduction signaling within fibroblasts, mediated by YAP1. Mouse embryos lacking YAP1 in fibroblasts exhibit both reduced tissue stiffness and develop lethal vascular defects. Translating our findings through biology-inspired vascular tissue engineering approaches will have substantial implications in regenerative medicine.
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Affiliation(s)
- Jordan Whisler
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Somayeh Shahreza
- Department of Mechanical Engineering, University College London, London, UK
| | | | - Nil Ege
- Tumour Cell Biology Laboratory, Francis Crick Institute, London, UK
- Mnemo Therapeutics, 101 Boulevard Murat, 75016 Paris, France
| | - Yousef Javanmardi
- Department of Mechanical Engineering, University College London, London, UK
| | - Andrea Malandrino
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Engineering and Research Center for Biomedical Engineering, Universitat Politècnica de Catalunya (UPC), Av. Eduard Maristany, 10-14 08019 Barcelona, Spain
| | - Ayushi Agrawal
- Department of Mechanical Engineering, University College London, London, UK
| | - Alessandro Fantin
- UCL Institute of Ophthalmology, University College London, London, UK
- Department of Biosciences, University of Milan, Via G. Celoria 26, 20133 Milan, Italy
| | - Bianca Serwinski
- Department of Mechanical Engineering, University College London, London, UK
- 199 Biotechnologies Ltd., Gloucester Road, London W2 6LD, UK
- Northeastern University London, London, E1W 1LP, UK
| | - Hesham Azizgolshani
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Clara Park
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Victoria Shone
- Experimental Histopathology Laboratory, Francis Crick Institute, London, UK
| | - Olukunle O. Demuren
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Amanda Del Rosario
- David H. Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Vincent L. Butty
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Natalie Holroyd
- UCL Centre for Advanced Biomedical Imaging, Paul O'Gorman Building, 72 Huntley Street, London, UK
| | | | - Steven Hooper
- Tumour Cell Biology Laboratory, Francis Crick Institute, London, UK
| | - Nicolas Szita
- Department of Biochemical Engineering, University College London, London, UK
| | - Laurie A. Boyer
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Simon Walker-Samuel
- UCL Centre for Advanced Biomedical Imaging, Paul O'Gorman Building, 72 Huntley Street, London, UK
| | - Boris Djordjevic
- Department of Mechanical Engineering, University College London, London, UK
- 199 Biotechnologies Ltd., Gloucester Road, London W2 6LD, UK
| | - Graham K. Sheridan
- School of Life Sciences, Queen’s Medical Centre, University of Nottingham, Nottingham, UK
| | - Lucy Collinson
- Electron Microscopy Laboratory, Francis Crick Institute, London, UK
| | - Fernando Calvo
- Instituto de Biomedicina y Biotecnología de Cantabria (Consejo Superior de Investigaciones Científicas, Universidad de Cantabria), Santander, Spain
| | | | - Erik Sahai
- Tumour Cell Biology Laboratory, Francis Crick Institute, London, UK
| | - Roger Kamm
- Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Emad Moeendarbary
- Department of Mechanical Engineering, University College London, London, UK
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
- 199 Biotechnologies Ltd., Gloucester Road, London W2 6LD, UK
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5
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Hall CM, Lasli S, Serwinski B, Djordjevic B, Sheridan GK, Moeendarbary E. Hippocampus of the APP NL-G-F mouse model of Alzheimer's disease exhibits region-specific tissue softening concomitant with elevated astrogliosis. Front Aging Neurosci 2023; 15:1212212. [PMID: 37547743 PMCID: PMC10398960 DOI: 10.3389/fnagi.2023.1212212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 07/03/2023] [Indexed: 08/08/2023] Open
Abstract
Widespread neurodegeneration, enlargement of cerebral ventricles, and atrophy of cortical and hippocampal brain structures are classic hallmarks of Alzheimer's disease (AD). Prominent macroscopic disturbances to the cytoarchitecture of the AD brain occur alongside changes in the mechanical properties of brain tissue, as reported in recent magnetic resonance elastography (MRE) measurements of human brain mechanics. Whilst MRE has many advantages, a significant shortcoming is its spatial resolution. Higher resolution "cellular scale" assessment of the mechanical alterations to brain regions involved in memory formation, such as the hippocampus, could provide fresh new insight into the etiology of AD. Characterization of brain tissue mechanics at the cellular length scale is the first stepping-stone to understanding how mechanosensitive neurons and glia are impacted by neurodegenerative disease-associated changes in their microenvironment. To provide insight into the microscale mechanics of aging brain tissue, we measured spatiotemporal changes in the mechanical properties of the hippocampus using high resolution atomic force microscopy (AFM) indentation tests on acute brain slices from young and aged wild-type mice and the APPNL-G-F mouse model. Several hippocampal regions in APPNL-G-F mice are significantly softer than age-matched wild-types, notably the dentate granule cell layer and the CA1 pyramidal cell layer. Interestingly, regional softening coincides with an increase in astrocyte reactivity, suggesting that amyloid pathology-mediated alterations to the mechanical properties of brain tissue may impact the function of mechanosensitive astrocytes. Our data also raise questions as to whether aberrant mechanotransduction signaling could impact the susceptibility of neurons to cellular stressors in their microenvironment.
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Affiliation(s)
- Chloe M. Hall
- Department of Mechanical Engineering, University College London, London, United Kingdom
- School of Applied Sciences, University of Brighton, Brighton, United Kingdom
| | - Soufian Lasli
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Bianca Serwinski
- Department of Mechanical Engineering, University College London, London, United Kingdom
- 199 Biotechnologies Ltd., London, United Kingdom
- Faculty of Social Sciences, Northeastern University London, London, United Kingdom
| | - Boris Djordjevic
- Department of Mechanical Engineering, University College London, London, United Kingdom
- 199 Biotechnologies Ltd., London, United Kingdom
| | - Graham K. Sheridan
- School of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Emad Moeendarbary
- Department of Mechanical Engineering, University College London, London, United Kingdom
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6
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Javanmardi Y, Agrawal A, Malandrino A, Lasli S, Chen M, Shahreza S, Serwinski B, Cammoun L, Li R, Jorfi M, Djordjevic B, Szita N, Spill F, Bertazzo S, Sheridan GK, Shenoy V, Calvo F, Kamm R, Moeendarbary E. Endothelium and Subendothelial Matrix Mechanics Modulate Cancer Cell Transendothelial Migration. Adv Sci (Weinh) 2023; 10:e2206554. [PMID: 37051804 PMCID: PMC10238207 DOI: 10.1002/advs.202206554] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 03/19/2023] [Indexed: 06/04/2023]
Abstract
Cancer cell extravasation, a key step in the metastatic cascade, involves cancer cell arrest on the endothelium, transendothelial migration (TEM), followed by the invasion into the subendothelial extracellular matrix (ECM) of distant tissues. While cancer research has mostly focused on the biomechanical interactions between tumor cells (TCs) and ECM, particularly at the primary tumor site, very little is known about the mechanical properties of endothelial cells and the subendothelial ECM and how they contribute to the extravasation process. Here, an integrated experimental and theoretical framework is developed to investigate the mechanical crosstalk between TCs, endothelium and subendothelial ECM during in vitro cancer cell extravasation. It is found that cancer cell actin-rich protrusions generate complex push-pull forces to initiate and drive TEM, while transmigration success also relies on the forces generated by the endothelium. Consequently, mechanical properties of the subendothelial ECM and endothelial actomyosin contractility that mediate the endothelial forces also impact the endothelium's resistance to cancer cell transmigration. These results indicate that mechanical features of distant tissues, including force interactions between the endothelium and the subendothelial ECM, are key determinants of metastatic organotropism.
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Affiliation(s)
- Yousef Javanmardi
- Department of Mechanical EngineeringUniversity College LondonTorrington PlaceLondonWC1E 7JEUK
| | - Ayushi Agrawal
- Department of Mechanical EngineeringUniversity College LondonTorrington PlaceLondonWC1E 7JEUK
| | - Andrea Malandrino
- Department of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMA02139USA
- Biomaterials, Biomechanics and Tissue Engineering GroupDepartment of Materials Science and Engineering and Research Center for Biomedical EngineeringUniversitat Politécnica de Catalunya (UPC)08019BarcelonaSpain
| | - Soufian Lasli
- Department of Mechanical EngineeringUniversity College LondonTorrington PlaceLondonWC1E 7JEUK
| | - Michelle Chen
- Department of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMA02139USA
| | - Somayeh Shahreza
- Department of Mechanical EngineeringUniversity College LondonTorrington PlaceLondonWC1E 7JEUK
| | - Bianca Serwinski
- Department of Mechanical EngineeringUniversity College LondonTorrington PlaceLondonWC1E 7JEUK
- 199 Biotechnologies LtdGloucester RoadLondonW2 6LDUK
| | - Leila Cammoun
- Department of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMA02139USA
| | - Ran Li
- Department of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMA02139USA
| | - Mehdi Jorfi
- Department of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMA02139USA
| | - Boris Djordjevic
- Department of Mechanical EngineeringUniversity College LondonTorrington PlaceLondonWC1E 7JEUK
- 199 Biotechnologies LtdGloucester RoadLondonW2 6LDUK
| | - Nicolas Szita
- Department of Biochemical EngineeringUniversity College LondonLondonWC1E 6BTUK
| | - Fabian Spill
- School of MathematicsUniversity of BirminghamEdgbastonBirminghamB152TSUK
| | - Sergio Bertazzo
- Department of Medical Physics and Biomedical EngineeringUniversity College LondonLondonWC1E 6BTUK
| | - Graham K Sheridan
- School of Life SciencesQueen's Medical CentreUniversity of NottinghamNottinghamNG7 2UHUK
| | - Vivek Shenoy
- Department of Materials Science and EngineeringUniversity of PennsylvaniaPhiladelphiaPA19104USA
| | - Fernando Calvo
- Instituto de Biomedicina y Biotecnología de Cantabria (Consejo Superior de Investigaciones Científicas, Universidad de Cantabria)Santander39011Spain
| | - Roger Kamm
- Department of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMA02139USA
| | - Emad Moeendarbary
- Department of Mechanical EngineeringUniversity College LondonTorrington PlaceLondonWC1E 7JEUK
- Department of Biological EngineeringMassachusetts Institute of TechnologyCambridgeMA02139USA
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Esteki MH, Malandrino A, Alemrajabi AA, Sheridan GK, Charras G, Moeendarbary E. Poroelastic osmoregulation of living cell volume. iScience 2021; 24:103482. [PMID: 34927026 PMCID: PMC8649806 DOI: 10.1016/j.isci.2021.103482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 08/19/2021] [Accepted: 11/19/2021] [Indexed: 11/22/2022] Open
Abstract
Cells maintain their volume through fine intracellular osmolarity regulation. Osmotic challenges drive fluid into or out of cells causing swelling or shrinkage, respectively. The dynamics of cell volume changes depending on the rheology of the cellular constituents and on how fast the fluid permeates through the membrane and cytoplasm. We investigated whether and how poroelasticity can describe volume dynamics in response to osmotic shocks. We exposed cells to osmotic perturbations and used defocusing epifluorescence microscopy on membrane-attached fluorescent nanospheres to track volume dynamics with high spatiotemporal resolution. We found that a poroelastic model that considers both geometrical and pressurization rates captures fluid-cytoskeleton interactions, which are rate-limiting factors in controlling volume changes at short timescales. Linking cellular responses to osmotic shocks and cell mechanics through poroelasticity can predict the cell state in health, disease, or in response to novel therapeutics. Cell height changes can be finely captured by defocusing microscopy Water permeation and cellular deformability regulate dynamics of cell volume changes Poroelasticity describes the dynamics of cell volume changes The response of cell to hypo or hyperosmotic shocks are modeled by poroelasticity
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Affiliation(s)
- Mohammad Hadi Esteki
- Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran.,Department of Mechanical Engineering, University College London, London, UK
| | - Andrea Malandrino
- Biomaterials, Biomechanics and Tissue Engineering Group, Department of Materials Science and Engineering, Universitat Politècnica de Catalunya, Barcelona, Spain
| | - Ali Akbar Alemrajabi
- Department of Mechanical Engineering, Isfahan University of Technology, Isfahan, Iran
| | - Graham K Sheridan
- School of Life Sciences, Queens Medical Centre, University of Nottingham, Nottingham, UK
| | - Guillaume Charras
- London Centre for Nanotechnology, University College London, London, UK.,Department of Cell and Developmental Biology, University College London, London, UK.,Institute for the Physics of Living Systems, University College London, London, UK
| | - Emad Moeendarbary
- Department of Mechanical Engineering, University College London, London, UK.,Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
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Mampay M, Flint MS, Sheridan GK. Tumour brain: Pretreatment cognitive and affective disorders caused by peripheral cancers. Br J Pharmacol 2021; 178:3977-3996. [PMID: 34029379 DOI: 10.1111/bph.15571] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2021] [Revised: 04/12/2021] [Accepted: 05/05/2021] [Indexed: 12/20/2022] Open
Abstract
People that develop extracranial cancers often display co-morbid neurological disorders, such as anxiety, depression and cognitive impairment, even before commencement of chemotherapy. This suggests bidirectional crosstalk between non-CNS tumours and the brain, which can regulate peripheral tumour growth. However, the reciprocal neurological effects of tumour progression on brain homeostasis are not well understood. Here, we review brain regions involved in regulating peripheral tumour development and how they, in turn, are adversely affected by advancing tumour burden. Tumour-induced activation of the immune system, blood-brain barrier breakdown and chronic neuroinflammation can lead to circadian rhythm dysfunction, sleep disturbances, aberrant glucocorticoid production, decreased hippocampal neurogenesis and dysregulation of neural network activity, resulting in depression and memory impairments. Given that cancer-related cognitive impairment diminishes patient quality of life, reduces adherence to chemotherapy and worsens cancer prognosis, it is essential that more research is focused at understanding how peripheral tumours affect brain homeostasis.
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Affiliation(s)
- Myrthe Mampay
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - Melanie S Flint
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - Graham K Sheridan
- School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK
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9
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Lizarraga-Valderrama LR, Sheridan GK. Extracellular vesicles and intercellular communication in the central nervous system. FEBS Lett 2021; 595:1391-1410. [PMID: 33728650 DOI: 10.1002/1873-3468.14074] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/07/2021] [Accepted: 03/08/2021] [Indexed: 12/30/2022]
Abstract
Neurons and glial cells of the central nervous system (CNS) release extracellular vesicles (EVs) to the interstitial fluid of the brain and spinal cord parenchyma. EVs contain proteins, nucleic acids and lipids that can be taken up by, and modulate the behaviour of, neighbouring recipient cells. The functions of EVs have been extensively studied in the context of neurodegenerative diseases. However, mechanisms involved in EV-mediated neuron-glial communication under physiological conditions or healthy ageing remain unclear. A better understanding of the myriad roles of EVs in CNS homeostasis is essential for the development of novel therapeutics to alleviate and reverse neurological disturbances of ageing. Proteomic studies are beginning to reveal cell type-specific EV cargo signatures that may one day allow us to target specific neuronal or glial cell populations in the treatment of debilitating neurological disorders. This review aims to synthesise the current literature regarding EV-mediated cell-cell communication in the brain, predominantly under physiological conditions.
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Affiliation(s)
| | - Graham K Sheridan
- School of Life Sciences, Queens Medical Centre, University of Nottingham, UK
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10
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Mampay M, Velasco-Estevez M, Rolle SO, Chaney AM, Boutin H, Dev KK, Moeendarbary E, Sheridan GK. Spatiotemporal immunolocalisation of REST in the brain of healthy ageing and Alzheimer's disease rats. FEBS Open Bio 2020; 11:146-163. [PMID: 33185010 PMCID: PMC7780110 DOI: 10.1002/2211-5463.13036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Revised: 10/25/2020] [Accepted: 11/04/2020] [Indexed: 12/30/2022] Open
Abstract
In the brain, REST (Repressor Element‐1 Silencing Transcription factor) is a key regulator of neuron cell‐specific gene expression. Nuclear translocation of neuronal REST has been shown to be neuroprotective in a healthy ageing context. In contrast, inability to upregulate nuclear REST is thought to leave ageing neurons vulnerable to neurodegenerative stimuli, such as Alzheimer’s disease (AD) pathology. Hippocampal and cortical neurons are known to be particularly susceptible to AD‐associated neurodegeneration. However, REST expression has not been extensively characterised in the healthy ageing brain. Here, we examined the spatiotemporal immunolocalisation of REST in the brains of healthy ageing wild‐type Fischer‐344 and transgenic Alzheimer’s disease rats (TgF344‐AD). Nuclear expression of REST increased from 6 months to 18 months of age in the hippocampus, frontal cortex and subiculum of wild‐type rats, but not in TgF344‐AD rats. No changes in REST were measured in more posterior cortical regions or in the thalamus. Interestingly, levels of the presynaptic marker synaptophysin, a known gene target of REST, were lower in CA1 hippocampal neurons of 18‐month TgF344‐AD rats compared to 18‐month wild‐types, suggesting that elevated nuclear REST may protect against synapse loss in the CA1 of 18‐month wild‐type rats. High REST expression in ageing wild‐type rats did not, however, protect against axonal loss nor against astroglial reactivity in the hippocampus. Taken together, our data confirm that changes in nuclear REST expression are context‐, age‐ and brain region‐specific. Moreover, key brain structures involved in learning and memory display elevated REST expression in healthy ageing wild‐type rats but not TgF344‐AD rats.
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Affiliation(s)
- Myrthe Mampay
- School of Pharmacy and Biomolecular Sciences, University of Brighton, UK
| | - María Velasco-Estevez
- Drug Development, Department of Physiology, School of Medicine, Trinity College Dublin, Ireland
| | - Sara O Rolle
- The Sainsbury Welcome Centre for Neural Circuits and Behaviour, University College London, UK
| | - Aisling M Chaney
- Faculty of Biology, Medicine and Health, School of Health Sciences, Division of Informatics, Imaging and Data Sciences, University of Manchester, UK
| | - Hervé Boutin
- Wolfson Molecular Imaging Centre, University of Manchester, UK.,Division of Neuroscience and Experimental Psychology, Faculty of Biology, Medicine and Health, School of Biological Sciences, University of Manchester, UK
| | - Kumlesh K Dev
- Drug Development, Department of Physiology, School of Medicine, Trinity College Dublin, Ireland
| | | | - Graham K Sheridan
- School of Life Sciences, Queens Medical Centre, University of Nottingham, UK
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11
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Hall CM, Moeendarbary E, Sheridan GK. Mechanobiology of the brain in ageing and Alzheimer's disease. Eur J Neurosci 2020; 53:3851-3878. [DOI: 10.1111/ejn.14766] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Revised: 04/20/2020] [Accepted: 04/23/2020] [Indexed: 02/07/2023]
Affiliation(s)
- Chloe M. Hall
- Department of Mechanical Engineering University College London London UK
- School of Pharmacy and Biomolecular Sciences University of Brighton Brighton UK
| | - Emad Moeendarbary
- Department of Mechanical Engineering University College London London UK
- Department of Biological Engineering Massachusetts Institute of Technology Cambridge MA USA
| | - Graham K. Sheridan
- School of Life Sciences Queens Medical Centre University of Nottingham Nottingham UK
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12
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Esteki MH, Alemrajabi AA, Hall CM, Sheridan GK, Azadi M, Moeendarbary E. A new framework for characterization of poroelastic materials using indentation. Acta Biomater 2020; 102:138-148. [PMID: 31715334 PMCID: PMC6958526 DOI: 10.1016/j.actbio.2019.11.010] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2019] [Revised: 11/03/2019] [Accepted: 11/06/2019] [Indexed: 01/07/2023]
Abstract
To characterize a poroelastic material, typically an indenter is pressed onto the surface of the material with a ramp of a finite approach velocity followed by a hold where the indenter displacement is kept constant. This leads to deformation of the porous matrix, pressurization of the interstitial fluid and relaxation due to redistribution of fluid through the pores. In most studies the poroelastic properties, including elastic modulus, Poisson ratio and poroelastic diffusion coefficient, are extracted by assuming an instantaneous step indentation. However, exerting step like indentation is not experimentally possible and usually a ramp indentation with a finite approach velocity is applied. Moreover, the poroelastic relaxation time highly depends on the approach velocity in addition to the poroelastic diffusion coefficient and the contact area. Here, we extensively studied the effect of indentation velocity using finite element simulations which has enabled the formulation of a new framework based on a master curve that incorporates the finite rise time. To verify our novel framework, the poroelastic properties of two types of hydrogels were extracted experimentally using indentation tests at both macro and micro scales. Our new framework that is based on consideration of finite approach velocity is experimentally easy to implement and provides a more accurate estimation of poroelastic properties. STATEMENT OF SIGNIFICANCE: Hydrogels, tissues and living cells are constituted of a sponge-like porous elastic matrix bathed in an interstitial fluid. It has been shown that these materials behave according to the theory of 'poroelasticity' when mechanically stimulated in a way similar to that experienced in organs within the body. In this theory, the rate at which the fluid-filled sponge can be deformed is limited by how fast interstitial fluid can redistribute within the sponge in response to deformation. Here, we simulated indentation experiments at different rates and formulated a new framework that inherently captures the effects of stimulation speed on the mechanical response of poroelastic materials. We validated our framework by conducting experiments at different length-scales on agarose and polyacrylamide hydrogels.
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Affiliation(s)
- Mohammad Hadi Esteki
- Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran; Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Ali Akbar Alemrajabi
- Department of Mechanical Engineering, Isfahan University of Technology, Isfahan 84156-83111, Iran
| | - Chloe M Hall
- Department of Mechanical Engineering, University College London, London, United Kingdom; School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, United Kingdom
| | - Graham K Sheridan
- School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, United Kingdom
| | - Mojtaba Azadi
- School of Engineering, College of Science and Engineering, San Francisco State University, San Francisco, CA 94132, United States; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Emad Moeendarbary
- Department of Mechanical Engineering, University College London, London, United Kingdom; Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States.
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13
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Velasco-Estevez M, Gadalla KKE, Liñan-Barba N, Cobb S, Dev KK, Sheridan GK. Inhibition of Piezo1 attenuates demyelination in the central nervous system. Glia 2019; 68:356-375. [PMID: 31596529 DOI: 10.1002/glia.23722] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 08/15/2019] [Accepted: 09/06/2019] [Indexed: 12/12/2022]
Abstract
Piezo1 is a mechanosensitive ion channel that facilitates the translation of extracellular mechanical cues to intracellular molecular signaling cascades through a process termed, mechanotransduction. In the central nervous system (CNS), mechanically gated ion channels are important regulators of neurodevelopmental processes such as axon guidance, neural stem cell differentiation, and myelination of axons by oligodendrocytes. Here, we present evidence that pharmacologically mediated overactivation of Piezo1 channels negatively regulates CNS myelination. Moreover, we found that the peptide GsMTx4, an antagonist of mechanosensitive cation channels such as Piezo1, is neuroprotective and prevents chemically induced demyelination. In contrast, the positive modulator of Piezo1 channel opening, Yoda-1, induces demyelination and neuronal damage. Using an ex vivo murine-derived organotypic cerebellar slice culture model, we demonstrate that GsMTx4 attenuates demyelination induced by the cytotoxic lipid, psychosine. Importantly, we confirmed the potential therapeutic effects of GsMTx4 peptide in vivo by co-administering it with lysophosphatidylcholine (LPC), via stereotactic injection, into the cerebral cortex of adult mice. GsMTx4 prevented both demyelination and neuronal damage usually caused by the intracortical injection of LPC in vivo; a well-characterized model of focal demyelination. GsMTx4 also attenuated both LPC-induced astrocyte toxicity and microglial reactivity within the lesion core. Overall, our data suggest that pharmacological activation of Piezo1 channels induces demyelination and that inhibition of mechanosensitive channels, using GsMTx4, may alleviate the secondary progressive neurodegeneration often present in the latter stages of demyelinating diseases.
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Affiliation(s)
- María Velasco-Estevez
- Drug Development, School of Medicine, Trinity College Dublin, Dublin, Ireland.,School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - Kamal K E Gadalla
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Núria Liñan-Barba
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - Stuart Cobb
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Kumlesh K Dev
- Drug Development, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Graham K Sheridan
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK.,School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK
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14
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Velasco-Estevez M, Rolle SO, Mampay M, Dev KK, Sheridan GK. Piezo1 regulates calcium oscillations and cytokine release from astrocytes. Glia 2019; 68:145-160. [PMID: 31433095 DOI: 10.1002/glia.23709] [Citation(s) in RCA: 56] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 07/16/2019] [Accepted: 08/07/2019] [Indexed: 12/11/2022]
Abstract
Astrocytes are important for information processing in the brain and they achieve this by fine-tuning neuronal communication via continuous uptake and release of biochemical modulators of neurotransmission and synaptic plasticity. Often overlooked are their important functions in mechanosensation. Indeed, astrocytes can detect pathophysiological changes in the mechanical properties of injured, ageing, or degenerating brain tissue. We have recently shown that astrocytes surrounding mechanically-stiff amyloid plaques upregulate the mechanosensitive ion channel, Piezo1. Moreover, ageing transgenic Alzheimer's rats harboring a chronic peripheral bacterial infection displayed enhanced Piezo1 expression in amyloid plaque-reactive astrocytes of the hippocampus and cerebral cortex. Here, we have shown that the bacterial endotoxin, lipopolysaccharide (LPS), also upregulates Piezo1 in primary mouse cortical astrocyte cultures in vitro. Activation of Piezo1, via the small molecule agonist Yoda1, enhanced Ca2+ influx in both control and LPS-stimulated astrocytes. Moreover, Yoda1 augmented intracellular Ca2+ oscillations but decreased subsequent Ca2+ influx in response to adenosine triphosphate (ATP) stimulation. Neither blocking nor activating Piezo1 affected cell viability. However, LPS-stimulated astrocyte cultures exposed to the Piezo1 activator, Yoda1, migrated significantly slower than reactive astrocytes treated with the mechanosensitive channel-blocking peptide, GsMTx4. Furthermore, our data show that activating Piezo1 channels inhibits the release of cytokines and chemokines, such as IL-1β, TNFα, and fractalkine (CX3 CL1), from LPS-stimulated astrocyte cultures. Taken together, our results suggest that astrocytic Piezo1 upregulation may act to dampen neuroinflammation and could be a useful drug target for neuroinflammatory disorders of the brain.
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Affiliation(s)
- María Velasco-Estevez
- Drug Development, Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Sara O Rolle
- Department of Bioengineering, Imperial College London, London, UK.,Francis Crick Institute, London, UK
| | - Myrthe Mampay
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - Kumlesh K Dev
- Drug Development, Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Graham K Sheridan
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK.,School of Life Sciences, Queen's Medical Centre, University of Nottingham, Nottingham, UK
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15
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Colin-York H, Javanmardi Y, Barbieri L, Li D, Korobchevskaya K, Guo Y, Hall C, Taylor A, Khuon S, Sheridan GK, Chew TL, Li D, Moeendarbary E, Fritzsche M. Spatiotemporally Super-Resolved Volumetric Traction Force Microscopy. Nano Lett 2019; 19:4427-4434. [PMID: 31199151 PMCID: PMC6628183 DOI: 10.1021/acs.nanolett.9b01196] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Revised: 06/12/2019] [Indexed: 05/21/2023]
Abstract
Quantification of mechanical forces is a major challenge across biomedical sciences. Yet such measurements are essential to understanding the role of biomechanics in cell regulation and function. Traction force microscopy remains the most broadly applied force probing technology but typically restricts itself to single-plane two-dimensional quantifications with limited spatiotemporal resolution. Here, we introduce an enhanced force measurement technique combining 3D super-resolution fluorescence structural illumination microscopy and traction force microscopy (3D-SIM-TFM) offering increased spatiotemporal resolution, opening-up unprecedented insights into physiological three-dimensional force production in living cells.
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Affiliation(s)
- Huw Colin-York
- MRC
Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
| | - Yousef Javanmardi
- Department
of Mechanical Engineering, University College
London, London WC1E 7JE, United Kingdom
| | - Liliana Barbieri
- MRC
Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
| | - Di Li
- National
Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
| | - Kseniya Korobchevskaya
- Kennedy
Institute for Rheumatology, University of
Oxford, Roosevelt Drive, Oxford OX3 7LF, United Kingdom
| | - Yuting Guo
- National
Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- College
of Life Sciences, University of Chinese
Academy of Sciences, Beijing 100049, China
| | - Chloe Hall
- Department
of Mechanical Engineering, University College
London, London WC1E 7JE, United Kingdom
| | - Aaron Taylor
- Howard Hughes
Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, Virginia 20147, United States
| | - Satya Khuon
- Howard Hughes
Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, Virginia 20147, United States
| | - Graham K. Sheridan
- School
of Pharmacy and Biomolecular Sciences, University
of Brighton, Brighton BN2 4AT, United Kingdom
| | - Teng-Leong Chew
- Howard Hughes
Medical Institute, Janelia Research Campus, 19700 Helix Drive, Ashburn, Virginia 20147, United States
| | - Dong Li
- National
Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China
- College
of Life Sciences, University of Chinese
Academy of Sciences, Beijing 100049, China
| | - Emad Moeendarbary
- Department
of Mechanical Engineering, University College
London, London WC1E 7JE, United Kingdom
- Department
of Biological Engineering, Massachusetts
Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Marco Fritzsche
- MRC
Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
- Kennedy
Institute for Rheumatology, University of
Oxford, Roosevelt Drive, Oxford OX3 7LF, United Kingdom
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16
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Mampay M, Sheridan GK. REST: An epigenetic regulator of neuronal stress responses in the young and ageing brain. Front Neuroendocrinol 2019; 53:100744. [PMID: 31004616 DOI: 10.1016/j.yfrne.2019.04.001] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/02/2019] [Revised: 04/03/2019] [Accepted: 04/11/2019] [Indexed: 12/27/2022]
Abstract
The transcriptional repressor REST (Repressor Element-1 Silencing Transcription factor) is a key modulator of the neuronal epigenome and targets genes involved in neuronal differentiation, axonal growth, vesicular transport, ion channel conductance and synaptic plasticity. Whilst its gene expression-modifying properties have been examined extensively in neuronal development, REST's response towards stress-induced neuronal insults has only recently been explored. Overall, REST appears to be an ideal candidate to fine-tune neuronal gene expression following different forms of cellular, neuropathological, psychological and physical stressors. Upregulation of REST is reportedly protective against premature neural stem cell depletion, neuronal hyperexcitability, oxidative stress, neuroendocrine system dysfunction and neuropathology. In contrast, neuronal REST activation has also been linked to neuronal dysfunction and neurodegeneration. Here, we highlight key findings and discrepancies surrounding our current understanding of REST's function in neuronal adaptation to stress and explore its potential role in neuronal stress resilience in the young and ageing brain.
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Affiliation(s)
- Myrthe Mampay
- Neuroimmunology & Neurotherapeutics Laboratory, School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton BN2 4GJ, UK
| | - Graham K Sheridan
- Neuroimmunology & Neurotherapeutics Laboratory, School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton BN2 4GJ, UK.
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17
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Velasco-Estevez M, Mampay M, Boutin H, Chaney A, Warn P, Sharp A, Burgess E, Moeendarbary E, Dev KK, Sheridan GK. Infection Augments Expression of Mechanosensing Piezo1 Channels in Amyloid Plaque-Reactive Astrocytes. Front Aging Neurosci 2018; 10:332. [PMID: 30405400 PMCID: PMC6204357 DOI: 10.3389/fnagi.2018.00332] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 10/01/2018] [Indexed: 01/07/2023] Open
Abstract
A defining pathophysiological hallmark of Alzheimer's disease (AD) is the amyloid plaque; an extracellular deposit of aggregated fibrillar Aβ1-42 peptides. Amyloid plaques are hard, brittle structures scattered throughout the hippocampus and cerebral cortex and are thought to cause hyperphosphorylation of tau, neurofibrillary tangles, and progressive neurodegeneration. Reactive astrocytes and microglia envelop the exterior of amyloid plaques and infiltrate their inner core. Glia are highly mechanosensitive cells and can almost certainly sense the mismatch between the normally soft mechanical environment of the brain and very stiff amyloid plaques via mechanosensing ion channels. Piezo1, a non-selective cation channel, can translate extracellular mechanical forces to intracellular molecular signaling cascades through a process known as mechanotransduction. Here, we utilized an aging transgenic rat model of AD (TgF344-AD) to study expression of mechanosensing Piezo1 ion channels in amyloid plaque-reactive astrocytes. We found that Piezo1 is upregulated with age in the hippocampus and cortex of 18-month old wild-type rats. However, more striking increases in Piezo1 were measured in the hippocampus of TgF344-AD rats compared to age-matched wild-type controls. Interestingly, repeated urinary tract infections with Escherichia coli bacteria, a common comorbidity in elderly people with dementia, caused further elevations in Piezo1 channel expression in the hippocampus and cortex of TgF344-AD rats. Taken together, we report that aging and peripheral infection augment amyloid plaque-induced upregulation of mechanoresponsive ion channels, such as Piezo1, in astrocytes. Further research is required to investigate the role of astrocytic Piezo1 in the Alzheimer's brain, whether modulating channel opening will protect or exacerbate the disease state, and most importantly, if Piezo1 could prove to be a novel drug target for age-related dementia.
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Affiliation(s)
- María Velasco-Estevez
- Neuroimmulology & Neurotherapeutics Laboratory, School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, United Kingdom
- Drug Development, Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Myrthe Mampay
- Neuroimmulology & Neurotherapeutics Laboratory, School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, United Kingdom
| | - Hervé Boutin
- Wolfson Molecular Imaging Centre, Faculty of Biology, Medicine and Health and Manchester Academic Health Sciences Centre, The University of Manchester, Manchester, United Kingdom
| | - Aisling Chaney
- Wolfson Molecular Imaging Centre, Faculty of Biology, Medicine and Health and Manchester Academic Health Sciences Centre, The University of Manchester, Manchester, United Kingdom
- Department of Radiology, Stanford University, Stanford, CA, United States
| | - Peter Warn
- Evotec (UK) Ltd., Manchester Science Park, Manchester, United Kingdom
| | - Andrew Sharp
- Evotec (UK) Ltd., Manchester Science Park, Manchester, United Kingdom
| | - Ellie Burgess
- Evotec (UK) Ltd., Manchester Science Park, Manchester, United Kingdom
| | - Emad Moeendarbary
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, United States
- Department of Mechanical Engineering, University College London, London, United Kingdom
| | - Kumlesh K. Dev
- Drug Development, Department of Physiology, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Graham K. Sheridan
- Neuroimmulology & Neurotherapeutics Laboratory, School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, United Kingdom
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18
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O'Sullivan SA, O'Sullivan C, Healy LM, Dev KK, Sheridan GK. Sphingosine 1-phosphate receptors regulate TLR4-induced CXCL5 release from astrocytes and microglia. J Neurochem 2018; 144:736-747. [PMID: 29377126 DOI: 10.1111/jnc.14313] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 01/06/2018] [Accepted: 01/18/2018] [Indexed: 12/13/2022]
Abstract
Sphingosine 1-phosphate receptors (S1PR) are G protein-coupled and compose a family with five subtypes, S1P1R-S1P5R. The drug Gilenya® (Novartis, Basel, Switzerland) (Fingolimod; FTY720) targets S1PRs and was the first oral therapy for patients with relapsing-remitting multiple sclerosis (MS). The phosphorylated form of FTY720 (pFTY720) binds S1PRs causing initial agonism, then subsequent receptor internalization and functional antagonism. Internalization of S1P1R attenuates sphingosine 1-phosphate (S1P)-mediated egress of lymphocytes from lymph nodes, limiting aberrant immune function in MS. pFTY720 also exerts direct actions on neurons and glial cells which express S1PRs. In this study, we investigated the regulation of pro-inflammatory chemokine release by S1PRs in enriched astrocytes and microglial cultures. Astrocytes and microglia were stimulated with lipopolysaccharide (LPS) and increases in C-X-C motif chemokine 5 (CXCL5), also known as LIX (lipopolysaccharide-induced CXC chemokine) expression were quantified. Results showed that pFTY720 attenuated LPS-induced CXCL5 (LIX) protein release from astrocytes, as did the S1P1R selective agonist, SEW2871. In addition, pFTY720 blocked messenger ribonucleic acid (mRNA) transcription of the chemokines, (i) CXCL5/LIX, (ii) C-X-C motif chemokine 10 (CXCL10) also known as interferon gamma-induced protein 10 (IP10) and (iii) chemokine (C-C motif) ligand 2 (CCL2) also known as monocyte chemoattractant protein 1 (MCP1). Interestingly, inhibition of sphingosine kinase attenuated LPS-induced increases in mRNA levels of all three chemokines, suggesting that LPS-TLR4 (Toll-like receptor 4) signalling may enhance chemokine expression via S1P-S1PR transactivation. Lastly, these observations were not limited to astrocytes since we also found that pFTY720 attenuated LPS-induced release of CXCL5 from microglia. These data highlight a role for S1PR signalling in regulating the levels of chemokines in glial cells and support the notion that pFTY720 efficacy in multiple sclerosis may involve the direct modulation of astrocytes and microglia.
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Affiliation(s)
- Sinead A O'Sullivan
- Drug Development, School of Medicine, Trinity College Dublin, Dublin, Ireland.,Department of Neurology, University of Chicago, Chicago, IL, USA
| | | | - Luke M Healy
- Drug Development, School of Medicine, Trinity College Dublin, Dublin, Ireland.,Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, QC, Canada
| | - Kumlesh K Dev
- Drug Development, School of Medicine, Trinity College Dublin, Dublin, Ireland
| | - Graham K Sheridan
- Drug Development, School of Medicine, Trinity College Dublin, Dublin, Ireland.,School of Pharmacy & Biomolecular Sciences, University of Brighton, Brighton, UK
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19
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Moeendarbary E, Weber IP, Sheridan GK, Koser DE, Soleman S, Haenzi B, Bradbury EJ, Fawcett J, Franze K. The soft mechanical signature of glial scars in the central nervous system. Nat Commun 2017; 8:14787. [PMID: 28317912 PMCID: PMC5364386 DOI: 10.1038/ncomms14787] [Citation(s) in RCA: 235] [Impact Index Per Article: 33.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 01/31/2017] [Indexed: 02/02/2023] Open
Abstract
Injury to the central nervous system (CNS) alters the molecular and cellular composition of neural tissue and leads to glial scarring, which inhibits the regrowth of damaged axons. Mammalian glial scars supposedly form a chemical and mechanical barrier to neuronal regeneration. While tremendous effort has been devoted to identifying molecular characteristics of the scar, very little is known about its mechanical properties. Here we characterize spatiotemporal changes of the elastic stiffness of the injured rat neocortex and spinal cord at 1.5 and three weeks post-injury using atomic force microscopy. In contrast to scars in other mammalian tissues, CNS tissue significantly softens after injury. Expression levels of glial intermediate filaments (GFAP, vimentin) and extracellular matrix components (laminin, collagen IV) correlate with tissue softening. As tissue stiffness is a regulator of neuronal growth, our results may help to understand why mammalian neurons do not regenerate after injury.
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Affiliation(s)
- Emad Moeendarbary
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK,Department of Biological Engineering, Massachusetts Institute of Technology, 77 Massachusetts Ave 56, Cambridge, Massachusetts 02139, USA,Department of Mechanical Engineering, University College London, London WC1E 7JE, UK,
| | - Isabell P. Weber
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Graham K. Sheridan
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK,School of Pharmacy and Biomolecular Sciences, University of Brighton, Lewes Road, Brighton BN2 4GJ, UK
| | - David E. Koser
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Sara Soleman
- John van Geest Centre for Brain Repair, University of Cambridge, Robinson Way, Cambridge CB2 0PY, UK
| | - Barbara Haenzi
- John van Geest Centre for Brain Repair, University of Cambridge, Robinson Way, Cambridge CB2 0PY, UK
| | - Elizabeth J. Bradbury
- Wolfson Centre for Age-Related Diseases, King's College London, Guy's Campus, London SE1 1UL, UK
| | - James Fawcett
- John van Geest Centre for Brain Repair, University of Cambridge, Robinson Way, Cambridge CB2 0PY, UK
| | - Kristian Franze
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK,
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20
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Velasco M, O'Sullivan C, Sheridan GK. Lysophosphatidic acid receptors (LPARs): Potential targets for the treatment of neuropathic pain. Neuropharmacology 2016; 113:608-617. [PMID: 27059127 DOI: 10.1016/j.neuropharm.2016.04.002] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 12/15/2015] [Accepted: 04/04/2016] [Indexed: 01/08/2023]
Abstract
Neuropathic pain can arise from lesions to peripheral or central nerve fibres leading to spontaneous action potential generation and a lowering of the nociceptive threshold. Clinically, neuropathic pain can manifest in many chronic disease states such as cancer, diabetes or multiple sclerosis (MS). The bioactive lipid, lysophosphatidic acid (LPA), via activation of its receptors (LPARs), is thought to play a central role in both triggering and maintaining neuropathic pain. In particular, following an acute nerve injury, the excitatory neurotransmitters glutamate and substance P are released from primary afferent neurons leading to upregulated synthesis of lysophosphatidylcholine (LPC), the precursor for LPA production. LPC is converted to LPA by autotaxin (ATX), which can then activate macrophages/microglia and modulate neuronal functioning. A ubiquitous feature of animal models of neuropathic pain is demyelination of damaged nerves. It is thought that LPA contributes to demyelination through several different mechanisms. Firstly, high levels of LPA are produced following macrophage/microglial activation that triggers a self-sustaining feed-forward loop of de novo LPA synthesis. Secondly, macrophage/microglial activation contributes to inflammation-mediated demyelination of axons, thus initiating neuropathic pain. Therefore, targeting LPA production and/or the family of LPA-activated G protein-coupled receptors (GPCRs) may prove to be fruitful clinical approaches to treating demyelination and the accompanying neuropathic pain. This review discusses our current understanding of the role of LPA/LPAR signalling in the initiation of neuropathic pain and suggests potential targeted strategies for its treatment. This article is part of the Special Issue entitled 'Lipid Sensing G Protein-Coupled Receptors in the CNS'.
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Affiliation(s)
- María Velasco
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton BN2 4GJ, UK
| | | | - Graham K Sheridan
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton BN2 4GJ, UK.
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21
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Healy LM, Sheridan GK, Pritchard AJ, Rutkowska A, Mullershausen F, Dev KK. Pathway specific modulation of S1P1 receptor signalling in rat and human astrocytes. Br J Pharmacol 2015; 169:1114-29. [PMID: 23587004 DOI: 10.1111/bph.12207] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2012] [Revised: 03/09/2013] [Accepted: 03/21/2013] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND AND PURPOSE The sphingosine 1-phosphate receptor subtype 1 (S1P1R) is modulated by phosphorylated FTY720 (pFTY720), which causes S1P1R internalization preventing lymphocyte migration thus limiting autoimmune response. Studies indicate that internalized S1P1Rs continue to signal, maintaining an inhibition of cAMP, thus raising question whether the effects of pFTY720 are due to transient initial agonism, functional antagonism and/or continued signalling. To further investigate this, the current study first determined if continued S1P1R activation is pathway specific. EXPERIMENTAL APPROACH Using human and rat astrocyte cultures, the effects of S1P1R activation on cAMP, pERK and Ca(2+) signalling was investigated. In addition, to examine the role of S1P1R redistribution on these events, a novel biologic (MNP301) that prevented pFTY720-mediated S1P1R redistribution was engineered. KEY RESULTS The data showed that pFTY720 induced long-lasting S1P1R redistribution and continued cAMP signalling in rat astrocytes. In contrast, pFTY720 induced a transient increase of Ca(2+) in astrocytes and subsequent antagonism of Ca(2+) signalling. Notably, while leaving pFTY720-induced cAMP signalling intact, the novel MNP301 peptide attenuated S1P1R-mediated Ca(2+) and pERK signalling in cultured rat astrocytes. CONCLUSIONS AND IMPLICATIONS These findings suggested that pFTY720 causes continued cAMP signalling that is not dependent on S1P1R redistribution and induces functional antagonism of Ca(2+) signalling after transient stimulation. To our knowledge, this is the first report demonstrating that pFTY720 causes continued signalling in one pathway (cAMP) versus functional antagonism of another pathway (Ca(2+)) and which also suggests that redistributed S1P1Rs may have differing signalling properties from those expressed at the surface.
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Affiliation(s)
- Luke M Healy
- Molecular Neuropharmacology, Department of Physiology, School of Medicine, Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland
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Sheridan GK, Wdowicz A, Pickering M, Watters O, Halley P, O'Sullivan NC, Mooney C, O'Connell DJ, O'Connor JJ, Murphy KJ. CX3CL1 is up-regulated in the rat hippocampus during memory-associated synaptic plasticity. Front Cell Neurosci 2014; 8:233. [PMID: 25161610 PMCID: PMC4130185 DOI: 10.3389/fncel.2014.00233] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/25/2014] [Indexed: 11/13/2022] Open
Abstract
Several cytokines and chemokines are now known to play normal physiological roles in the brain where they act as key regulators of communication between neurons, glia, and microglia. In particular, cytokines and chemokines can affect cardinal cellular and molecular processes of hippocampal-dependent long-term memory consolidation including synaptic plasticity, synaptic scaling and neurogenesis. The chemokine, CX3CL1 (fractalkine), has been shown to modulate synaptic transmission and long-term potentiation (LTP) in the CA1 pyramidal cell layer of the hippocampus. Here, we confirm widespread expression of CX3CL1 on mature neurons in the adult rat hippocampus. We report an up-regulation in CX3CL1 protein expression in the CA1, CA3 and dentate gyrus (DG) of the rat hippocampus 2 h after spatial learning in the water maze task. Moreover, the same temporal increase in CX3CL1 was evident following LTP-inducing theta-burst stimulation in the DG. At physiologically relevant concentrations, CX3CL1 inhibited LTP maintenance in the DG. This attenuation in dentate LTP was lost in the presence of GABAA receptor/chloride channel antagonism. CX3CL1 also had opposing actions on glutamate-mediated rise in intracellular calcium in hippocampal organotypic slice cultures in the presence and absence of GABAA receptor/chloride channel blockade. Using primary dissociated hippocampal cultures, we established that CX3CL1 reduces glutamate-mediated intracellular calcium rises in both neurons and glia in a dose dependent manner. In conclusion, CX3CL1 is up-regulated in the hippocampus during a brief temporal window following spatial learning the purpose of which may be to regulate glutamate-mediated neurotransmission tone. Our data supports a possible role for this chemokine in the protective plasticity process of synaptic scaling.
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Affiliation(s)
- Graham K Sheridan
- Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland ; Department of Physiology, Development and Neuroscience, University of Cambridge Cambridge, UK
| | - Anita Wdowicz
- Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - Mark Pickering
- School of Medicine and Medical Science, Health Sciences Centre, University College Dublin Dublin, Ireland
| | - Orla Watters
- UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - Paul Halley
- Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - Niamh C O'Sullivan
- UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - Claire Mooney
- Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - David J O'Connell
- UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - John J O'Connor
- UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
| | - Keith J Murphy
- Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin Dublin, Ireland
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Sheridan GK, Moeendarbary E, Pickering M, O'Connor JJ, Murphy KJ. Theta-burst stimulation of hippocampal slices induces network-level calcium oscillations and activates analogous gene transcription to spatial learning. PLoS One 2014; 9:e100546. [PMID: 24950243 PMCID: PMC4065069 DOI: 10.1371/journal.pone.0100546] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2014] [Accepted: 05/28/2014] [Indexed: 01/24/2023] Open
Abstract
Over four decades ago, it was discovered that high-frequency stimulation of the dentate gyrus induces long-term potentiation (LTP) of synaptic transmission. LTP is believed to underlie how we process and code external stimuli before converting it to salient information that we store as 'memories'. It has been shown that rats performing spatial learning tasks display theta-frequency (3–12 Hz) hippocampal neural activity. Moreover, administering theta-burst stimulation (TBS) to hippocampal slices can induce LTP. TBS triggers a sustained rise in intracellular calcium [Ca2+]i in neurons leading to new protein synthesis important for LTP maintenance. In this study, we measured TBS-induced [Ca2+]i oscillations in thousands of cells at increasing distances from the source of stimulation. Following TBS, a calcium wave propagates radially with an average speed of 5.2 µm/s and triggers multiple and regular [Ca2+]i oscillations in the hippocampus. Interestingly, the number and frequency of [Ca2+]i fluctuations post-TBS increased with respect to distance from the electrode. During the post-tetanic phase, 18% of cells exhibited 3 peaks in [Ca2+]i with a frequency of 17 mHz, whereas 2.3% of cells distributed further from the electrode displayed 8 [Ca2+]i oscillations at 33 mHz. We suggest that these observed [Ca2+]i oscillations could lead to activation of transcription factors involved in synaptic plasticity. In particular, the transcription factor, NF-κB, has been implicated in memory formation and is up-regulated after LTP induction. We measured increased activation of NF-κB 30 min post-TBS in CA1 pyramidal cells and also observed similar temporal up-regulation of NF-κB levels in CA1 neurons following water maze training in rats. Therefore, TBS of hippocampal slice cultures in vitro can mimic the cell type-specific up-regulations in activated NF-κB following spatial learning in vivo. This indicates that TBS may induce similar transcriptional changes to spatial learning and that TBS-triggered [Ca2+]i oscillations could activate memory-associated gene expression.
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Affiliation(s)
- Graham K. Sheridan
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
- * E-mail:
| | | | - Mark Pickering
- School of Medicine and Medical Science, Health Sciences Centre, University College Dublin, Dublin, Ireland
| | - John J. O'Connor
- UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin, Ireland
| | - Keith J. Murphy
- Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Dublin, Ireland
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Sheridan GK, Dev KK. Targeting S1P receptors in experimental autoimmune encephalomyelitis in mice improves early deficits in locomotor activity and increases ultrasonic vocalisations. Sci Rep 2014; 4:5051. [PMID: 24851861 PMCID: PMC4031479 DOI: 10.1038/srep05051] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 05/06/2014] [Indexed: 12/31/2022] Open
Abstract
Fingolimod (FTY720) is an oral therapy for relapsing remitting multiple sclerosis (MS) and targets sphingosine 1-phosphate receptors (S1PRs). FTY720 also rescues animals from experimental autoimmune encephalomyelitis (EAE), an animal model of MS. The protective effects of FTY720 in EAE are primarily scored manually by examining weight loss and limb paralysis that begins around 10-12 days after immunisation. To our knowledge, pre-clinical effects of FTY720 on animal behaviour early in EAE have not been explored. Here, we developed an automated behaviour monitoring system to examine the early effects of FTY720 on subtle pre-symptomatic behaviour of mice induced with EAE. Our automated home-cage monitoring system (AHC-MS) enabled non-contact detection of movement and ultrasonic vocalisations (USVs) of mice induced with EAE, thus allowing detection of subtle changes in mouse behaviour before paralysis occurs. Mice receiving FTY720 emit longer USVs and display higher levels of motor activity than vehicle-treated EAE mice before clinical symptoms become apparent. Importantly, this study promotes the 3Rs ethics (replacement, reduction and refinement) in the EAE animal model and may also improve pre-screening of potentially novel MS therapies. In addition, this is the first report showing the early effects of FTY720 in EAE which underscores its protective effects.
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MESH Headings
- Animals
- Disease Models, Animal
- Encephalomyelitis, Autoimmune, Experimental/metabolism
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Encephalomyelitis, Autoimmune, Experimental/prevention & control
- Female
- Fingolimod Hydrochloride
- Immunosuppressive Agents/pharmacology
- Lysophospholipids/metabolism
- Mice
- Mice, Inbred C57BL
- Motor Activity/drug effects
- Motor Activity/physiology
- Propylene Glycols/pharmacology
- Receptors, Lysosphingolipid/antagonists & inhibitors
- Receptors, Lysosphingolipid/genetics
- Receptors, Lysosphingolipid/metabolism
- Sphingosine/analogs & derivatives
- Sphingosine/metabolism
- Sphingosine/pharmacology
- Vocalization, Animal/drug effects
- Vocalization, Animal/physiology
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Affiliation(s)
- Graham K. Sheridan
- Drug Development, School of Medicine, Trinity College Dublin, Dublin, Ireland
- Current address: Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
| | - Kumlesh K. Dev
- Drug Development, School of Medicine, Trinity College Dublin, Dublin, Ireland
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Abstract
An essential aspect of normal brain function is the bidirectional interaction and communication between neurons and neighbouring glial cells. To this end, the brain has evolved ligand-receptor partnerships that facilitate crosstalk between different cell types. The chemokine, fractalkine (FKN), is expressed on neuronal cells, and its receptor, CX(3)CR1, is predominantly expressed on microglia. This review focuses on several important functional roles for FKN/CX(3)CR1 in both health and disease of the central nervous system. It has been posited that FKN is involved in microglial infiltration of the brain during development. Microglia, in turn, are implicated in the developmental synaptic pruning that occurs during brain maturation. The abundance of FKN on mature hippocampal neurons suggests a homeostatic non-inflammatory role in mechanisms of learning and memory. There is substantial evidence describing a role for FKN in hippocampal synaptic plasticity. FKN, on the one hand, appears to prevent excess microglial activation in the absence of injury while promoting activation of microglia and astrocytes during inflammatory episodes. Thus, FKN appears to be neuroprotective in some settings, whereas it contributes to neuronal damage in others. Many progressive neuroinflammatory disorders that are associated with increased microglial activation, such as Alzheimer's disease, show disruption of the FKN/CX(3)CR1 communication system. Thus, targeting CX(3)CR1 receptor hyperactivation with specific antagonists in such neuroinflammatory conditions may eventually lead to novel neurotherapeutics.
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Affiliation(s)
- Graham K Sheridan
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge CB2 3DY, UK
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Sheridan GK, Dev KK. S1P1 receptor subtype inhibits demyelination and regulates chemokine release in cerebellar slice cultures. Glia 2011; 60:382-92. [DOI: 10.1002/glia.22272] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2011] [Accepted: 11/01/2011] [Indexed: 12/14/2022]
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McKee AG, Loscher JS, O'Sullivan NC, Chadderton N, Palfi A, Batti L, Sheridan GK, O'Shea S, Moran M, McCabe O, Fernández AB, Pangalos MN, O'Connor JJ, Regan CM, O'Connor WT, Humphries P, Farrar GJ, Murphy KJ. AAV-mediated chronic over-expression of SNAP-25 in adult rat dorsal hippocampus impairs memory-associated synaptic plasticity. J Neurochem 2009; 112:991-1004. [PMID: 20002519 DOI: 10.1111/j.1471-4159.2009.06516.x] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Long-term memory is formed by alterations in glutamate-dependent excitatory synaptic transmission, which is in turn regulated by synaptosomal protein of 25 kDa (SNAP-25), a key component of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor complex essential for exocytosis of neurotransmitter-filled synaptic vesicles. Both reduced and excessive SNAP-25 activity has been implicated in various disease states that involve cognitive dysfunctions such as attention deficit hyperactivity disorder, schizophrenia and Alzheimer's disease. Here, we over-express SNAP-25 in the adult rat dorsal hippocampus by infusion of a recombinant adeno-associated virus vector, to evaluate the consequence of late adolescent-adult dysfunction of the soluble N-ethylmaleimide-sensitive factor attachment protein receptor protein in the absence of developmental disruption. We report a specific and significant increase in the levels of extracellular glutamate detectable by microdialysis and a reduction in paired-pulse facilitation in the hippocampus. In addition, SNAP-25 over-expression produced cognitive deficits, delaying acquisition of a spatial map in the water maze and impairing contextual fear conditioning, both tasks known to be dorsal hippocampal dependent. The high background transmission state and pre-synaptic dysfunction likely result in interference with requisite synapse selection during spatial and fear memory consolidation. Together these studies provide the first evidence that excess SNAP-25 activity, restricted to the adult period, is sufficient to mediate significant deficits in the memory formation process.
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Affiliation(s)
- Alex G McKee
- Applied Neurotherapeutics Research Group, Smurfit Institute of Genetics, Trinity College Dublin, Dublin, Ireland.
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Sheridan GK, Pickering M, Twomey C, Moynagh PN, O’Connor JJ, Murphy KJ. NF-kappaB activity in distinct neural subtypes of the rat hippocampus: Influence of time and GABA antagonism in acute slice preparations. Learn Mem 2007; 14:525-32. [PMID: 17686946 PMCID: PMC1951791 DOI: 10.1101/lm.590007] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Hippocampal memory-associated synaptic plasticity is driven by a cascade of transcription and new protein synthesis. In vitro electrophysiological studies on acute hippocampal slices have elucidated much of what we know about this molecular cascade. Curiously, these slices require a period of "equilibration" for the recovery of electrophysiological properties such as LTP, implying ongoing time-dependent molecular events necessary for full expression of plasticity. Using standard immunofluorescence combined with confocal imaging and a novel data analysis approach, we implicate the transcription factor NF-kappaB in this plasticity-related molecular adaptation during equilibration. Marked differences in basal NF-kappaB activity in distinct cell types of the hippocampus were observed, with the amount of active NF-kappaB increasing throughout the 2-h equilibration period in all cell types. Moreover, distinct hippocampal neuronal subfields exhibit very different responses to the GABA(A) receptor blocker picrotoxin, the presence of which is required to achieve LTP in the dentate gyrus. These findings have implications for the use of acute hippocampal slices to study the effects of compounds that signal through NF-kappaB on synaptic plasticity. Further investigation into the cellular processes that occur during this molecular adaptation may increase our understanding of plasticity-related events common to both LTP and memory formation.
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Affiliation(s)
- Graham K. Sheridan
- Applied Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Mark Pickering
- Applied Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Clare Twomey
- Applied Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Paul N. Moynagh
- Institute of Immunology, Department of Biology, National University of Ireland, Maynooth, Co. Kildare, Ireland
| | - John J. O’Connor
- Applied Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
| | - Keith J. Murphy
- Applied Neurotherapeutics Research Group, UCD School of Biomolecular and Biomedical Science, Conway Institute, University College Dublin, Belfield, Dublin 4, Ireland
- Corresponding author.E-mail ; fax +353-01-7166920
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O'Sullivan NC, McGettigan PA, Sheridan GK, Pickering M, Conboy L, O'Connor JJ, Moynagh PN, Higgins DG, Regan CM, Murphy KJ. Temporal change in gene expression in the rat dentate gyrus following passive avoidance learning. J Neurochem 2007; 101:1085-98. [PMID: 17298388 DOI: 10.1111/j.1471-4159.2006.04418.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
A learning event initiates a cascade of altered gene expression leading to synaptic remodelling within the hippocampal dentate gyrus, a structure vital to memory formation. To illuminate this transcriptional program of synaptic plasticity we used microarrays to quantify mRNA from the rat dentate gyrus at increasing times following passive avoidance learning. Approximately, 500 known genes were transcriptionally regulated across the 24 h post-training period. The 0-2 h period saw up-regulation of genes involved in transcription while genes with a role in synaptic/cytoskeletal structure increased 0-6 h, consistent with structural rearrangements known to occur at these times. The most striking feature was the profound down-regulation, across all functional groups, 12 h post-training. Bioinformatics analysis identified the likely transcription factors controlling gene expression in each post-training period. The role of NF kappa B, implicated in the early post-training period was subsequently confirmed with activation and nuclear translocation seen in dentate granule neurons following training. mRNA changes for four genes, LRP3 (0 h), alpha actin (3 h), SNAP25 and NSF (6-12 h), were validated at message and/or protein level and shown to be learning specific. Thus, the memory-associated transcriptional cascade supports the cardinal periods of synaptic loosening, reorganisation and selection thought to underpin the process of long-term memory consolidation in the hippocampus.
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Affiliation(s)
- Niamh C O'Sullivan
- Applied Neurotherapeutics Research Group, UCD Schools of Biomolecular and Biomedical Science, UCD Conway Institute, University College Dublin, Belfield, Dublin, Ireland.
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