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Pinto MJ, Bizien L, Fabre JM, Ðukanović N, Lepetz V, Henderson F, Pujol M, Sala RW, Tarpin T, Popa D, Triller A, Léna C, Fabre V, Bessis A. Microglial TNFα controls daily changes in synaptic GABAARs and sleep slow waves. J Cell Biol 2024; 223:e202401041. [PMID: 38695719 PMCID: PMC11070559 DOI: 10.1083/jcb.202401041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 03/18/2024] [Accepted: 03/28/2024] [Indexed: 05/08/2024] Open
Abstract
Microglia sense the changes in their environment. How microglia actively translate these changes into suitable cues to adapt brain physiology is unknown. We reveal an activity-dependent regulation of cortical inhibitory synapses by microglia, driven by purinergic signaling acting on P2RX7 and mediated by microglia-derived TNFα. We demonstrate that sleep induces microglia-dependent synaptic enrichment of GABAARs in a manner dependent on microglial TNFα and P2RX7. We further show that microglia-specific depletion of TNFα alters slow waves during NREM sleep and blunt memory consolidation in sleep-dependent learning tasks. Together, our results reveal that microglia orchestrate sleep-intrinsic plasticity of synaptic GABAARs, sculpt sleep slow waves, and support memory consolidation.
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Affiliation(s)
- Maria Joana Pinto
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Lucy Bizien
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Julie M.J. Fabre
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Nina Ðukanović
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Valentin Lepetz
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Fiona Henderson
- Neurosciences Paris Seine—Institut de Biologie Paris Seine (NPS—IBPS), CNRS, INSERM, Sorbonne Universités, Paris, France
| | - Marine Pujol
- Neurosciences Paris Seine—Institut de Biologie Paris Seine (NPS—IBPS), CNRS, INSERM, Sorbonne Universités, Paris, France
| | - Romain W. Sala
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Thibault Tarpin
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Daniela Popa
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Antoine Triller
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Clément Léna
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
| | - Véronique Fabre
- Neurosciences Paris Seine—Institut de Biologie Paris Seine (NPS—IBPS), CNRS, INSERM, Sorbonne Universités, Paris, France
| | - Alain Bessis
- Institut de Biologie de l’École Normale Supérieure (IBENS), École Normale Supérieure, CNRS, INSERM, Université PSL, Paris, France
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Chausse B, Malorny N, Lewen A, Poschet G, Berndt N, Kann O. Metabolic flexibility ensures proper neuronal network function in moderate neuroinflammation. Sci Rep 2024; 14:14405. [PMID: 38909138 PMCID: PMC11193723 DOI: 10.1038/s41598-024-64872-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Accepted: 06/13/2024] [Indexed: 06/24/2024] Open
Abstract
Microglia, brain-resident macrophages, can acquire distinct functional phenotypes, which are supported by differential reprogramming of cell metabolism. These adaptations include remodeling in glycolytic and mitochondrial metabolic fluxes, potentially altering energy substrate availability at the tissue level. This phenomenon may be highly relevant in the brain, where metabolism must be precisely regulated to maintain appropriate neuronal excitability and synaptic transmission. Direct evidence that microglia can impact on neuronal energy metabolism has been widely lacking, however. Combining molecular profiling, electrophysiology, oxygen microsensor recordings and mathematical modeling, we investigated microglia-mediated disturbances in brain energetics during neuroinflammation. Our results suggest that proinflammatory microglia showing enhanced nitric oxide release and decreased CX3CR1 expression transiently increase the tissue lactate/glucose ratio that depends on transcriptional reprogramming in microglia, not in neurons. In this condition, neuronal network activity such as gamma oscillations (30-70 Hz) can be fueled by increased ATP production in mitochondria, which is reflected by elevated oxygen consumption. During dysregulated inflammation, high energy demand and low glucose availability can be boundary conditions for neuronal metabolic fitness as revealed by kinetic modeling of single neuron energetics. Collectively, these findings indicate that metabolic flexibility protects neuronal network function against alterations in local substrate availability during moderate neuroinflammation.
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Affiliation(s)
- Bruno Chausse
- Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany.
- MEDISS Doctoral Program, INF 110, Heidelberg University, 69120, Heidelberg, Germany.
| | - Nikolai Malorny
- Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Andrea Lewen
- Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany
| | - Gernot Poschet
- Metabolomics Core Technology Platform, Centre for Organismal Studies, Heidelberg University, 69120, Heidelberg, Germany
| | - Nikolaus Berndt
- Department of Molecular Toxicology, German Institute of Human Nutrition Potsdam-Rehbruecke (DIfE), 14558, Nuthetal, Germany
- Institute of Computer-Assisted Cardiovascular Medicine, Deutsches Herzzentrum der Charité (DHZC), 13353, Berlin, Germany
- Charité - Universitätsmedizin Berlin, corporate member of Freie Universität Berlin and Humboldt-Universität zu Berlin, 10117, Berlin, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, Heidelberg University, Im Neuenheimer Feld 326, 69120, Heidelberg, Germany.
- Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, 69120, Heidelberg, Germany.
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3
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Chamera K, Curzytek K, Kamińska K, Leśkiewicz M, Basta-Kaim A. Prenatal Immune Challenge Differentiates the Effect of Aripiprazole and Risperidone on CD200-CD200R and CX3CL1-CX3CR1 Dyads and Microglial Polarization: A Study in Organotypic Cortical Cultures. Life (Basel) 2024; 14:721. [PMID: 38929704 PMCID: PMC11205240 DOI: 10.3390/life14060721] [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: 02/06/2024] [Revised: 04/20/2024] [Accepted: 05/30/2024] [Indexed: 06/28/2024] Open
Abstract
Microglia are the primary innate immune cells of the central nervous system and extensively contribute to brain homeostasis. Dysfunctional or excessive activity of microglia may be associated with several neuropsychiatric disorders, including schizophrenia. Therefore, we examined whether aripiprazole and risperidone could influence the expression of the Cd200-Cd200r and Cx3cl1-Cx3cr1 axes, which are crucial for the regulation of microglial activity and interactions of these cells with neurons. Additionally, we evaluated the impact of these drugs on microglial pro- and anti-inflammatory markers (Cd40, Il-1β, Il-6, Cebpb, Cd206, Arg1, Il-10 and Tgf-β) and cytokine release (IL-6, IL-10). The research was executed in organotypic cortical cultures (OCCs) prepared from the offspring of control rats (control OCCs) or those exposed to maternal immune activation (MIA OCCs), which allows for the exploration of schizophrenia-like disturbances in animals. All experiments were performed under basal conditions and after additional stimulation with lipopolysaccharide (LPS), following the "two-hit" hypothesis of schizophrenia. We found that MIA diminished the mRNA level of Cd200r and affected the OCCs' response to additional LPS exposure in terms of this parameter. LPS downregulated the Cx3cr1 expression and profoundly changed the mRNA levels of pro- and anti-inflammatory microglial markers in both types of OCCs. Risperidone increased Cd200 expression in MIA OCCs, while aripiprazole treatment elevated the gene levels of the Cx3cl1-Cx3cr1 dyad in control OCCs. The antipsychotics limited the LPS-generated increase in the expression of proinflammatory factors (Il-1β and Il-6) and enhanced the mRNA levels of anti-inflammatory components (Cd206 and Tgf-β) of microglial polarization, mostly in the absence of the MIA procedure. Finally, we observed a more pronounced modulating impact of aripiprazole on the expression of pro- and anti-inflammatory cytokines when compared to risperidone in MIA OCCs. In conclusion, our data suggest that MIA might influence microglial activation and crosstalk of microglial cells with neurons, whereas aripiprazole and risperidone could beneficially affect these changes in OCCs.
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Affiliation(s)
| | | | | | | | - Agnieszka Basta-Kaim
- Laboratory of Immunoendocrinology, Department of Experimental Neuroendocrinology, Maj Institute of Pharmacology, Polish Academy of Sciences, 12 Smętna St., 31-343 Kraków, Poland
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4
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Kann O. Lactate as a supplemental fuel for synaptic transmission and neuronal network oscillations: Potentials and limitations. J Neurochem 2024; 168:608-631. [PMID: 37309602 DOI: 10.1111/jnc.15867] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 05/15/2023] [Accepted: 05/18/2023] [Indexed: 06/14/2023]
Abstract
Lactate shuttled from the blood circulation, astrocytes, oligodendrocytes or even activated microglia (resident macrophages) to neurons has been hypothesized to represent a major source of pyruvate compared to what is normally produced endogenously by neuronal glucose metabolism. However, the role of lactate oxidation in fueling neuronal signaling associated with complex cortex function, such as perception, motor activity, and memory formation, is widely unclear. This issue has been experimentally addressed using electrophysiology in hippocampal slice preparations (ex vivo) that permit the induction of different neural network activation states by electrical stimulation, optogenetic tools or receptor ligand application. Collectively, these studies suggest that lactate in the absence of glucose (lactate only) impairs gamma (30-70 Hz) and theta-gamma oscillations, which feature high energy demand revealed by the cerebral metabolic rate of oxygen (CMRO2, set to 100%). The impairment comprises oscillation attenuation or moderate neural bursts (excitation-inhibition imbalance). The bursting is suppressed by elevating the glucose fraction in energy substrate supply. By contrast, lactate can retain certain electric stimulus-induced neural population responses and intermittent sharp wave-ripple activity that features lower energy expenditure (CMRO2 of about 65%). Lactate utilization increases the oxygen consumption by about 9% during sharp wave-ripples reflecting enhanced adenosine-5'-triphosphate (ATP) synthesis by oxidative phosphorylation in mitochondria. Moreover, lactate attenuates neurotransmission in glutamatergic pyramidal cells and fast-spiking, γ-aminobutyric acid (GABA)ergic interneurons by reducing neurotransmitter release from presynaptic terminals. By contrast, the generation and propagation of action potentials in the axon is regular. In conclusion, lactate is less effective than glucose and potentially detrimental during neural network rhythms featuring high energetic costs, likely through the lack of some obligatory ATP synthesis by aerobic glycolysis at excitatory and inhibitory synapses. High lactate/glucose ratios might contribute to central fatigue, cognitive impairment, and epileptic seizures partially seen, for instance, during exhaustive physical exercise, hypoglycemia and neuroinflammation.
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Affiliation(s)
- Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
- Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
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5
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Partiot E, Gorda B, Lutz W, Lebrun S, Khalfi P, Mora S, Charlot B, Majzoub K, Desagher S, Ganesh G, Colomb S, Gaudin R. Organotypic culture of human brain explants as a preclinical model for AI-driven antiviral studies. EMBO Mol Med 2024; 16:1004-1026. [PMID: 38472366 PMCID: PMC11018746 DOI: 10.1038/s44321-024-00039-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 02/02/2024] [Accepted: 02/05/2024] [Indexed: 03/14/2024] Open
Abstract
Viral neuroinfections represent a major health burden for which the development of antivirals is needed. Antiviral compounds that target the consequences of a brain infection (symptomatic treatment) rather than the cause (direct-acting antivirals) constitute a promising mitigation strategy that requires to be investigated in relevant models. However, physiological surrogates mimicking an adult human cortex are lacking, limiting our understanding of the mechanisms associated with viro-induced neurological disorders. Here, we optimized the Organotypic culture of Post-mortem Adult human cortical Brain explants (OPAB) as a preclinical platform for Artificial Intelligence (AI)-driven antiviral studies. OPAB shows robust viability over weeks, well-preserved 3D cytoarchitecture, viral permissiveness, and spontaneous local field potential (LFP). Using LFP as a surrogate for neurohealth, we developed a machine learning framework to predict with high confidence the infection status of OPAB. As a proof-of-concept, we showed that antiviral-treated OPAB could partially restore LFP-based electrical activity of infected OPAB in a donor-dependent manner. Together, we propose OPAB as a physiologically relevant and versatile model to study neuroinfections and beyond, providing a platform for preclinical drug discovery.
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Affiliation(s)
- Emma Partiot
- CNRS, Institut de Recherche en Infectiologie de Montpellier (IRIM), 34293, Montpellier, France
- Univ Montpellier, 34090, Montpellier, France
| | - Barbara Gorda
- CNRS, Institut de Recherche en Infectiologie de Montpellier (IRIM), 34293, Montpellier, France
- Univ Montpellier, 34090, Montpellier, France
| | - Willy Lutz
- CNRS, Institut de Recherche en Infectiologie de Montpellier (IRIM), 34293, Montpellier, France
- Univ Montpellier, 34090, Montpellier, France
| | - Solène Lebrun
- CNRS, Institut de Recherche en Infectiologie de Montpellier (IRIM), 34293, Montpellier, France
- Univ Montpellier, 34090, Montpellier, France
| | - Pierre Khalfi
- Univ Montpellier, 34090, Montpellier, France
- CNRS, Institut de Génétique Moléculaire de Montpellier (IGMM), 34293, Montpellier, France
| | - Stéphan Mora
- Univ Montpellier, 34090, Montpellier, France
- CNRS, Institut de Génétique Moléculaire de Montpellier (IGMM), 34293, Montpellier, France
| | - Benoit Charlot
- Univ Montpellier, 34090, Montpellier, France
- Institut d'Electronique et des Systèmes IES, CNRS, 860 Rue de St - Priest Bâtiment 5, 34090, Montpellier, France
| | - Karim Majzoub
- Univ Montpellier, 34090, Montpellier, France
- CNRS, Institut de Génétique Moléculaire de Montpellier (IGMM), 34293, Montpellier, France
| | - Solange Desagher
- CNRS, Institut de Recherche en Infectiologie de Montpellier (IRIM), 34293, Montpellier, France
- Univ Montpellier, 34090, Montpellier, France
- CNRS, Institut de Génétique Moléculaire de Montpellier (IGMM), 34293, Montpellier, France
| | - Gowrishankar Ganesh
- Univ Montpellier, 34090, Montpellier, France
- UM-CNRS Laboratoire d'Informatique de Robotique et de Microelectronique de Montpellier (LIRMM), 161, Rue Ada, 34090, Montpellier, France
| | - Sophie Colomb
- Univ Montpellier, 34090, Montpellier, France
- Equipe de droit pénal et sciences forensiques de Montpellier (EDPFM), Univ. Montpellier, Département de médecine légale, Pôle Urgences, Centre Hospitalo-Universitaire de Montpellier, 371 Avenue du Doyen Gaston Giraud, 34285, Montpellier, France
| | - Raphael Gaudin
- CNRS, Institut de Recherche en Infectiologie de Montpellier (IRIM), 34293, Montpellier, France.
- Univ Montpellier, 34090, Montpellier, France.
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6
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Connors KA, Frey ZD, Demers MJ, Wills ZP, Hartman AL. Acute Rift Valley fever virus infection induces inflammatory cytokines and cell death in ex vivo rat brain slice culture. J Gen Virol 2024; 105:001970. [PMID: 38546100 PMCID: PMC10995633 DOI: 10.1099/jgv.0.001970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2023] [Accepted: 03/02/2024] [Indexed: 04/04/2024] Open
Abstract
Rift Valley fever virus (RVFV) is an emerging arboviral disease with pandemic potential. While infection is often self-limiting, a subset of individuals may develop late-onset encephalitis, accounting for up to 20 % of severe cases. Importantly, individuals displaying neurologic disease have up to a 53 % case fatality rate, yet the neuropathogenesis of RVFV infection remains understudied. In this study, we evaluated whether ex vivo postnatal rat brain slice cultures (BSCs) could be used to evaluate RVFV infection in the central nervous system. BSCs mounted an inflammatory response after slicing, which resolved over time, and they were viable in culture for at least 12 days. Infection of rat BSCs with pathogenic RVFV strain ZH501 induced tissue damage and apoptosis over 48 h. Viral replication in BSCs reached up to 1×107 p.f.u. equivalents/ml, depending on inoculation dose. Confocal immunofluorescent microscopy of cleared slices confirmed direct infection of neurons as well as activation of microglia and astrocytes. Further, RVFV-infected rat BSCs produced antiviral cytokines and chemokines, including MCP-1 and GRO/KC. This study demonstrates that rat BSCs support replication of RVFV for ex vivo studies of neuropathogenesis. This allows for continued and complementary investigation into RVFV infection in an ex vivo postnatal brain slice culture format.
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Affiliation(s)
- Kaleigh A. Connors
- Department of Infectious Disease and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA, USA
| | - Zachary D. Frey
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA, USA
| | - Matthew J. Demers
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA, USA
| | - Zachary P. Wills
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Amy L. Hartman
- Department of Infectious Disease and Microbiology, School of Public Health, University of Pittsburgh, Pittsburgh, PA, USA
- Center for Vaccine Research, University of Pittsburgh, Pittsburgh, PA, USA
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7
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Larson KC, Martens LH, Marconi M, Dejesus C, Bruhn S, Miller TA, Tate B, Levenson JM. Preclinical translational platform of neuroinflammatory disease biology relevant to neurodegenerative disease. J Neuroinflammation 2024; 21:37. [PMID: 38297405 PMCID: PMC10832185 DOI: 10.1186/s12974-024-03029-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 01/23/2024] [Indexed: 02/02/2024] Open
Abstract
Neuroinflammation is a key driver of neurodegenerative disease, however the tools available to model this disease biology at the systems level are lacking. We describe a translational drug discovery platform based on organotypic culture of murine cortical brain slices that recapitulate disease-relevant neuroinflammatory biology. After an acute injury response, the brain slices assume a chronic neuroinflammatory state marked by transcriptomic profiles indicative of activation of microglia and astrocytes and loss of neuronal function. Microglia are necessary for manifestation of this neuroinflammation, as depletion of microglia prior to isolation of the brain slices prevents both activation of astrocytes and robust loss of synaptic function genes. The transcriptomic pattern of neuroinflammation in the mouse platform is present in published datasets derived from patients with amyotrophic lateral sclerosis, Huntington's disease, and frontotemporal dementia. Pharmacological utility of the platform was validated by demonstrating reversal of microglial activation and the overall transcriptomic signature with transforming growth factor-β. Additional anti-inflammatory targets were screened and inhibitors of glucocorticoid receptors, COX-2, dihydrofolate reductase, and NLRP3 inflammasome all failed to reverse the neuroinflammatory signature. Bioinformatics analysis of the neuroinflammatory signature identified protein tyrosine phosphatase non-receptor type 11 (PTPN11/SHP2) as a potential target. Three structurally distinct inhibitors of PTPN11 (RMC-4550, TN0155, IACS-13909) reversed the neuroinflammatory disease signature. Collectively, these results highlight the utility of this novel neuroinflammatory platform for facilitating identification and validation of targets for neuroinflammatory neurodegenerative disease drug discovery.
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Affiliation(s)
- Kelley C Larson
- Vigil Neuroscience, Watertown, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Lauren H Martens
- , Neumora Therapeutics, Watertown, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Michael Marconi
- Department of Molecular Pathology, Massachusetts General Hospital, Boston, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Christopher Dejesus
- Atalanta Therapeutics, Boston, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Suzanne Bruhn
- Charcot-Marie-Tooth Association, Glenolden, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Thomas A Miller
- Walden Biosciences, Cambridge, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Barbara Tate
- FARA, Homestead, USA
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA
| | - Jonathan M Levenson
- FireCyte Therapeutics, Beverly, USA.
- Tiaki Therapeutics, Inc., c/o Dementia Discovery Fund, 201 Washington Street, 39th Floor, Boston, MA, 02108, USA.
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8
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Wiener JP, Desire S, Garliyev V, Lyssenko III N, Praticò D, Lyssenko NN. Down-Regulation of ABCA7 in Human Microglia, Astrocyte and THP-1 Cell Lines by Cholesterol Depletion, IL-1β and TNFα, or PMA. Cells 2023; 12:2143. [PMID: 37681876 PMCID: PMC10486366 DOI: 10.3390/cells12172143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/04/2023] [Accepted: 08/18/2023] [Indexed: 09/09/2023] Open
Abstract
Adenosine triphosphate-binding cassette transporter subfamily A member 7 (ABCA7) is a major risk factor for Alzheimer's disease. Human neural cell lines were used to investigate the regulation of ABCA7 expression by cholesterol and pro-inflammatory cytokines. Cholesterol was depleted by methyl-β-cyclodextrin, followed by treatment with rosuvastatin to suppress de novo synthesis, while the cells underwent adjustment to low cholesterol. Cholesterol depletion by 50-76% decreased ABCA7 expression by ~40% in C20 microglia and ~21% in A172 astrocytes but had no effect on the protein in SK-N-SH neurons. Cholesterol depletion also suppressed ABCA7 in HMC3 microglia. Previously, cholesterol loss was reported to up-regulate ABCA7 in murine macrophages. ABCA7 was down-regulated during PMA-induced differentiation of human THP-1 monocytes to macrophages. But, cholesterol depletion in THP-1 macrophages by ~71% had no effect on ABCA7. IL-1β and TNFα reduced ABCA7 expression in C20 and HMC3 microglia but not in A172 astrocytes or SK-N-SH neurons. IL-6 did not affect ABCA7 in the neural cells. These findings suggest that ABCA7 is active in regular homeostasis in human neural cells, is regulated by cholesterol in a cell type-dependent manner, i.e., cholesterol depletion down-regulates it in human neuroglia but not neurons, and is incompatible with IL-1β and TNFα inflammatory responses in human microglia.
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Affiliation(s)
| | | | | | | | | | - Nicholas N. Lyssenko
- Alzheimer’s Center at Temple, Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA
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9
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Tian Y, Milic J, Monasor LS, Chakraborty R, Wang S, Yuan Y, Asare Y, Behrends C, Tahirovic S, Bernhagen J. The COP9 signalosome reduces neuroinflammation and attenuates ischemic neuronal stress in organotypic brain slice culture model. Cell Mol Life Sci 2023; 80:262. [PMID: 37597109 PMCID: PMC10439869 DOI: 10.1007/s00018-023-04911-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 07/06/2023] [Accepted: 08/04/2023] [Indexed: 08/21/2023]
Abstract
The constitutive photomorphogenesis 9 (COP9) signalosome (CSN) is a deNEDDylase controlling ubiquitination activity of cullin-RING-E3 ligases (CRLs) and thus the levels of key cellular proteins. While the CSN and its catalytic subunit CSN5 have been extensively studied in cancer, its role in inflammatory and neurological diseases is less understood. Following verification that CSN5 is expressed in mouse and human brain, here we studied the role of the CSN in neuroinflammation and ischemic neuronal damage employing models of relevant brain-resident cell types, an ex vivo organotypic brain slice culture model, and the CRL NEDDylation state-modifying drugs MLN4924 and CSN5i-3, which mimic and inhibit, respectively, CSN5 deNEDDylase activity. Untargeted mass spectrometry-based proteomics revealed that MLN4924 and CSN5i-3 substantially alter the microglial proteome, including inflammation-related proteins. Applying these drugs and mimicking microglial and endothelial inflammation as well as ischemic neuronal stress by TNF and oxygen-glucose-deprivation/reoxygenation (OGD/RO) treatment, respectively, we could link CSN5/CSN-mediated cullin deNEDDylation to reduction of microglial inflammation, attenuated cerebral endothelial inflammation, improved barrier integrity, as well as protection from ischemic stress-induced neuronal cell death. Specifically, MLN4924 reduced phagocytic activity, motility, and inflammatory cytokine expression of microglial cells, and this was linked to inhibition of inflammation-induced NF-κB and Akt signaling. Inversely, Csn5 knockdown and CSN5i-3 increased NF-κB signaling. Moreover, MLN4924 abrogated TNF-induced NF-κB signaling in cerebral microvascular endothelial cells (hCMECs) and rescued hCMEC monolayers from OGD/RO-triggered barrier leakage, while CSN5i-3 exacerbated permeability. In an ex vivo organotypic brain slice model of ischemia/reperfusion stress, MLN4924 protected from neuronal death, while CSN5i-3 impaired neuronal survival. Neuronal damage was attributable to microglial activation and inflammatory cytokines, as indicated by microglial shape tracking and TNF-blocking experiments. Our results indicate a protective role of the CSN in neuroinflammation via brain-resident cell types involved in ischemic brain disease and implicate CSN activity-mimicking deNEDDylating drugs as potential therapeutics.
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Affiliation(s)
- Yuan Tian
- Vascular Biology, Institute for Stroke and Dementia Research (ISD), LMU Klinikum, Ludwig-Maximilian-University (LMU) Munich, Feodor-Lynen-Straße 17, 81377, Munich, Germany
- Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, UK
| | - Jelena Milic
- Vascular Biology, Institute for Stroke and Dementia Research (ISD), LMU Klinikum, Ludwig-Maximilian-University (LMU) Munich, Feodor-Lynen-Straße 17, 81377, Munich, Germany
| | | | - Rahul Chakraborty
- Munich Cluster for Systems Neurology (SyNergy), Medical Faculty, LMU Munich, 81377, Munich, Germany
| | - Sijia Wang
- Vascular Biology, Institute for Stroke and Dementia Research (ISD), LMU Klinikum, Ludwig-Maximilian-University (LMU) Munich, Feodor-Lynen-Straße 17, 81377, Munich, Germany
- Shenzhen People's Hospital, Shenzhen, Guangdong Province, China
| | - Yue Yuan
- Vascular Biology, Institute for Stroke and Dementia Research (ISD), LMU Klinikum, Ludwig-Maximilian-University (LMU) Munich, Feodor-Lynen-Straße 17, 81377, Munich, Germany
| | - Yaw Asare
- Translational Stroke Research, Institute for Stroke and Dementia Research (ISD), LMU Klinikum, LMU Munich, 81377, Munich, Germany
| | - Christian Behrends
- Munich Cluster for Systems Neurology (SyNergy), Medical Faculty, LMU Munich, 81377, Munich, Germany
| | - Sabina Tahirovic
- German Center for Neurodegenerative Diseases (DZNE), 81377, Munich, Germany
| | - Jürgen Bernhagen
- Vascular Biology, Institute for Stroke and Dementia Research (ISD), LMU Klinikum, Ludwig-Maximilian-University (LMU) Munich, Feodor-Lynen-Straße 17, 81377, Munich, Germany.
- Munich Cluster for Systems Neurology (SyNergy), Medical Faculty, LMU Munich, 81377, Munich, Germany.
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10
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Kemppainen S, Huber N, Willman RM, Zamora A, Mäkinen P, Martiskainen H, Takalo M, Haapasalo A, Sobrino T, González Gómez MA, Piñeiro Y, Rivas J, Himmelreich U, Hiltunen M. Organotypic Hippocampal Slice Cultures from Adult Tauopathy Mice and Theragnostic Evaluation of Nanomaterial Phospho-TAU Antibody-Conjugates. Cells 2023; 12:1422. [PMID: 37408256 DOI: 10.3390/cells12101422] [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: 04/21/2023] [Revised: 05/12/2023] [Accepted: 05/15/2023] [Indexed: 07/07/2023] Open
Abstract
Organotypic slice culture models surpass conventional in vitro methods in many aspects. They retain all tissue-resident cell types and tissue hierarchy. For studying multifactorial neurodegenerative diseases such as tauopathies, it is crucial to maintain cellular crosstalk in an accessible model system. Organotypic slice cultures from postnatal tissue are an established research tool, but adult tissue-originating systems are missing, yet necessary, as young tissue-originating systems cannot fully model adult or senescent brains. To establish an adult-originating slice culture system for tauopathy studies, we made hippocampal slice cultures from transgenic 5-month-old hTau.P301S mice. In addition to the comprehensive characterization, we set out to test a novel antibody for hyperphosphorylated TAU (pTAU, B6), with and without a nanomaterial conjugate. Adult hippocampal slices retained intact hippocampal layers, astrocytes, and functional microglia during culturing. The P301S-slice neurons expressed pTAU throughout the granular cell layer and secreted pTAU to the culture medium, whereas the wildtype slices did not. Additionally, cytotoxicity and inflammation-related determinants were increased in the P301S slices. Using fluorescence microscopy, we showed target engagement of the B6 antibody to pTAU-expressing neurons and a subtle but consistent decrease in intracellular pTAU with the B6 treatment. Collectively, this tauopathy slice culture model enables measuring the extracellular and intracellular effects of different mechanistic or therapeutic manipulations on TAU pathology in adult tissue without the hindrance of the blood-brain barrier.
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Affiliation(s)
- Susanna Kemppainen
- Institute of Biomedicine, University of Eastern Finland, 70211 Kuopio, Finland
| | - Nadine Huber
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
| | - Roosa-Maria Willman
- Institute of Biomedicine, University of Eastern Finland, 70211 Kuopio, Finland
| | - Ana Zamora
- Molecular Imaging and Photonics, KU Leuven, 3001 Leuven, Belgium
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium
| | - Petra Mäkinen
- Institute of Biomedicine, University of Eastern Finland, 70211 Kuopio, Finland
| | - Henna Martiskainen
- Institute of Biomedicine, University of Eastern Finland, 70211 Kuopio, Finland
| | - Mari Takalo
- Institute of Biomedicine, University of Eastern Finland, 70211 Kuopio, Finland
| | - Annakaisa Haapasalo
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
| | - Tomás Sobrino
- NeuroAging Group (NEURAL), Clinical Neurosciences Research Laboratory (LINC), Health Research Institute of Santiago de Compostela (IDIS), 15706 Santiago de Compostela, Spain
| | - Manuel Antonio González Gómez
- Institute of Materials, Applied Physics Department, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Yolanda Piñeiro
- Institute of Materials, Applied Physics Department, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - José Rivas
- Institute of Materials, Applied Physics Department, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain
| | - Uwe Himmelreich
- Biomedical MRI, Department of Imaging and Pathology, KU Leuven, 3000 Leuven, Belgium
| | - Mikko Hiltunen
- Institute of Biomedicine, University of Eastern Finland, 70211 Kuopio, Finland
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11
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Cammarota M, Ferlenghi F, Vacondio F, Vincenzi F, Varani K, Bedini A, Rivara S, Mor M, Boscia F. Combined targeting of fatty acid amide hydrolase and melatonin receptors promotes neuroprotection and stimulates inflammation resolution in rats. Br J Pharmacol 2022; 180:1316-1338. [PMID: 36526591 DOI: 10.1111/bph.16014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Revised: 11/09/2022] [Accepted: 12/07/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND AND PURPOSE Devising novel strategies to therapeutically favour inflammation resolution and provide neuroprotection is an unmet clinical need. Enhancing endocannabinoid tone by inhibiting the catabolic enzyme fatty acid amide hydrolase (FAAH), or stimulating melatonin receptors has therapeutic potential to treat neuropathological states in which neuroinflammation plays a central role. EXPERIMENTAL APPROACH A rodent hippocampal explant model of inflammatory injury was used to assess the effects of UCM1341, a dual-acting compound with FAAH inhibitory action and agonist activity at melatonin receptors, against neuroinflammatory damage. FAAH activity was measured by a radiometric assay, and N-acylethanolamine levels were assessed by HPLC-MS/MS methods. FAAH distribution, evolution of inflammation and the contribution of UCM1341 to the expression of proteins controlling macrophage behaviour were investigated by biochemical and confocal analyses. KEY RESULTS UCM1341 exhibited greater neuroprotection against neuroinflammatory degeneration, compared with the reference compounds URB597 (FAAH inhibitor) and melatonin. During neuroinflammation, UCM1341 augmented the levels of anandamide and N-oleoylethanolamine, but not N-palmitoylethanolamine, up-regulated PPAR-α levels, attenuated demyelination and prevented the release of TNF-α. UCM1341 modulated inflammatory responses by contributing to microglia/macrophage polarization, stimulating formation of lipid-laden macrophages and regulating expression of proteins controlling cholesterol metabolism and efflux. The neuroprotective effects of UCM1341 were prevented by PPARα, TRPV1 and melatonin receptor antagonists. CONCLUSION AND IMPLICATIONS UCM1341, by enhancing endocannabinoid and melatoninergic signalling, benefits neuroprotection and stimulates inflammation resolution pathways. Our findings provide an encouraging prospect of therapeutically targeting endocannabinoid and melatoninergic systems in inflammatory demyelinating states in the CNS.
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Affiliation(s)
- Mariarosaria Cammarota
- Division of Pharmacology, Department of Neuroscience, Reproductive Sciences and Dentistry, School of Medicine, Federico II University of Naples, Naples, Italy
| | | | | | - Fabrizio Vincenzi
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
| | - Katia Varani
- Department of Translational Medicine, University of Ferrara, Ferrara, Italy
| | - Annalida Bedini
- Department of Biomolecular Sciences, University of Urbino 'Carlo Bo', Urbino, Italy
| | - Silvia Rivara
- Department of Food and Drug, University of Parma, Parma, Italy
| | - Marco Mor
- Department of Food and Drug, University of Parma, Parma, Italy
| | - Francesca Boscia
- Division of Pharmacology, Department of Neuroscience, Reproductive Sciences and Dentistry, School of Medicine, Federico II University of Naples, Naples, Italy
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12
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Kann O, Almouhanna F, Chausse B. Interferon γ: a master cytokine in microglia-mediated neural network dysfunction and neurodegeneration. Trends Neurosci 2022; 45:913-927. [PMID: 36283867 DOI: 10.1016/j.tins.2022.10.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2022] [Revised: 09/30/2022] [Accepted: 10/06/2022] [Indexed: 11/06/2022]
Abstract
Traditionally, lymphocytic interferon γ (IFN-γ) was considered to be a simple 'booster' of proinflammatory responses by microglia (brain-resident macrophages) during bacterial or viral infection. Recent slice culture (in situ) and in vivo studies suggest, however, that IFN-γ has a unique role in microglial activation. Priming by IFN-γ results in proliferation (microgliosis), enhanced synapse elimination, and moderate nitric oxide release sufficient to impair synaptic transmission, gamma rhythm activity, and cognitive functions. Moreover, IFN-γ is pivotal for driving Toll-like receptor (TLR)-activated microglia into neurotoxic phenotypes that induce energetic and oxidative stress, severe network dysfunction, and neuronal death. Pharmacological targeting of activated microglia could be beneficial during elevated IFN-γ levels, blood-brain barrier leakage, and parenchymal T lymphocyte infiltration associated with, for instance, encephalitis, multiple sclerosis, and Alzheimer's disease.
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Affiliation(s)
- Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany; Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, D-69120 Heidelberg, Germany.
| | - Fadi Almouhanna
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
| | - Bruno Chausse
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120 Heidelberg, Germany
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13
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Cakir B, Kiral FR, Park IH. Advanced in vitro models: Microglia in action. Neuron 2022; 110:3444-3457. [PMID: 36327894 DOI: 10.1016/j.neuron.2022.10.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2022] [Revised: 09/28/2022] [Accepted: 10/04/2022] [Indexed: 11/05/2022]
Abstract
In the central nervous system (CNS), microglia carry out multiple tasks related to brain development, maintenance of brain homeostasis, and function of the CNS. Recent advanced in vitro model systems allow us to perform more detailed and specific analyses of microglial functions in the CNS. The development of human pluripotent stem cells (hPSCs)-based 2D and 3D cell culture methods, particularly advancements in brain organoid models, offers a better platform to dissect microglial function in various contexts. Despite the improvement of these methods, there are still definite restrictions. Understanding their drawbacks and benefits ensures their proper use. In this primer, we review current developments regarding in vitro microglial production and characterization and their use to address fundamental questions about microglial function in healthy and diseased states, and we discuss potential future improvements with a particular emphasis on brain organoid models.
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Affiliation(s)
- Bilal Cakir
- Department of Genetics, Yale Stem Cell Center, Child Study Center, Yale School of Medicine, New Haven, CT 06520, USA.
| | - Ferdi Ridvan Kiral
- Department of Genetics, Yale Stem Cell Center, Child Study Center, Yale School of Medicine, New Haven, CT 06520, USA
| | - In-Hyun Park
- Department of Genetics, Yale Stem Cell Center, Child Study Center, Yale School of Medicine, New Haven, CT 06520, USA.
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14
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Garcia G, Pinto S, Ferreira S, Lopes D, Serrador MJ, Fernandes A, Vaz AR, de Mendonça A, Edenhofer F, Malm T, Koistinaho J, Brites D. Emerging Role of miR-21-5p in Neuron-Glia Dysregulation and Exosome Transfer Using Multiple Models of Alzheimer's Disease. Cells 2022; 11:3377. [PMID: 36359774 PMCID: PMC9655962 DOI: 10.3390/cells11213377] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 10/09/2022] [Accepted: 10/19/2022] [Indexed: 08/25/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder associated with neuron-glia dysfunction and dysregulated miRNAs. We previously reported upregulated miR-124/miR-21 in AD neurons and their exosomes. However, their glial distribution, phenotypic alterations and exosomal spread are scarcely documented. Here, we show glial cell activation and miR-21 overexpression in mouse organotypic hippocampal slices transplanted with SH-SY5Y cells expressing the human APP695 Swedish mutation. The upregulation of miR-21 only in the CSF from a small series of mild cognitive impairment (MCI) AD patients, but not in non-AD MCI individuals, supports its discriminatory potential. Microglia, neurons, and astrocytes differentiated from the same induced pluripotent stem cells from PSEN1ΔE9 AD patients all showed miR-21 elevation. In AD neurons, miR-124/miR-21 overexpression was recapitulated in their exosomes. In AD microglia, the upregulation of iNOS and miR-21/miR-146a supports their activation. AD astrocytes manifested a restrained inflammatory profile, with high miR-21 but low miR-155 and depleted exosomal miRNAs. Their immunostimulation with C1q + IL-1α + TNF-α induced morphological alterations and increased S100B, inflammatory transcripts, sAPPβ, cytokine release and exosomal miR-21. PPARα, a target of miR-21, was found to be repressed in all models, except in neurons, likely due to concomitant miR-125b elevation. The data from these AD models highlight miR-21 as a promising biomarker and a disease-modifying target to be further explored.
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Affiliation(s)
- Gonçalo Garcia
- Neuroinflammation, Signaling and Neuroregeneration Lab, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
- Department of Pharmaceutical Sciences and Medicines, Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Sara Pinto
- Neuroinflammation, Signaling and Neuroregeneration Lab, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
- Instituto de Medicina Molecular, Faculdade de Medicina, Universidade de Lisboa, 1649-028 Lisbon, Portugal
| | - Sofia Ferreira
- Neuroinflammation, Signaling and Neuroregeneration Lab, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Daniela Lopes
- Neuroinflammation, Signaling and Neuroregeneration Lab, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Maria João Serrador
- Neuroinflammation, Signaling and Neuroregeneration Lab, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Adelaide Fernandes
- Department of Pharmaceutical Sciences and Medicines, Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
- Central Nervous System, Blood and Peripheral Inflammation Lab, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | - Ana Rita Vaz
- Neuroinflammation, Signaling and Neuroregeneration Lab, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
- Department of Pharmaceutical Sciences and Medicines, Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
| | | | - Frank Edenhofer
- Department of Genomics, Stem Cell Biology and Regenerative Medicine, Center for Molecular Biosciences, University of Innsbruck, 6020 Innsbruck, Austria
| | - Tarja Malm
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
| | - Jari Koistinaho
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70211 Kuopio, Finland
- Neuroscience Center, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, 00014 Helsinki, Finland
| | - Dora Brites
- Neuroinflammation, Signaling and Neuroregeneration Lab, Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
- Department of Pharmaceutical Sciences and Medicines, Faculty of Pharmacy, Universidade de Lisboa, 1649-003 Lisbon, Portugal
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15
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Steiner K, Humpel C. Effects of Ischemia on the Migratory Capacity of Microglia Along Collagen Microcontact Prints on Organotypic Mouse Cortex Brain Slices. Front Cell Neurosci 2022; 16:858802. [PMID: 35783100 PMCID: PMC9243317 DOI: 10.3389/fncel.2022.858802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Accepted: 05/24/2022] [Indexed: 11/13/2022] Open
Abstract
Ischemic stroke is a severe insult in the brain causing cell death, inflammation, and activation of microglia. Microglia are the immune cells of the brain and play a role in any inflammatory process during neurodegeneration. Microglia are round ameboid and migrate to the lesion site, where they differentiate into ramified forms and activated phagocytic microglia. On the other hand, microglia can also release growth factors to repair degeneration. The aim of the present study is to explore the migratory capacity of microglia after ischemic insults. Organotypic brain slices of the mouse cortex (300 μm) were prepared. In order to study migration, the slices were connected to collagen-loaded microcontact prints (with or without monocyte chemoattractant protein-1, MCP-1) on the membranes. Slices were stimulated with lipopolysaccharide (LPS) for maximal microglial activation. Ischemic insults were simulated with oxygen-glucose deprivation (OGD) and acidosis (pH 6.5) for 3 days. After 3 weeks in culture, slices were fixed and immunohistochemically stained for the microglial markers Iba1, CD11b and macrophage-like antigen. Our data show that Iba1+ microglia migrated along the microcontact prints, differentiate and phagocyte 1.0 μm fluorescent microbeads. LPS significantly enhanced the number of round ameboid migrating microglia, while OGD and acidosis enhanced the number of ramified activated microglia. The effect was not visible on slices without any μCP and was most potent in μCP with MCP-1. We conclude that OGD and acidosis activate ramification and exhibit a similar mechanism, while LPS only activates round ameboid microglia. Collagen-loaded microcontact prints connected to mouse brain slices are a potent method to study activation and migration of microglia ex vivo.
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16
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McKenna M, Filteau JR, Butler B, Sluis K, Chungyoun M, Schimek N, Nance E. Organotypic whole hemisphere brain slice models to study the effects of donor age and oxygen-glucose-deprivation on the extracellular properties of cortical and striatal tissue. J Biol Eng 2022; 16:14. [PMID: 35698088 PMCID: PMC9195469 DOI: 10.1186/s13036-022-00293-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 05/21/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The brain extracellular environment is involved in many critical processes associated with neurodevelopment, neural function, and repair following injury. Organization of the extracellular matrix and properties of the extracellular space vary throughout development and across different brain regions, motivating the need for platforms that provide access to multiple brain regions at different stages of development. We demonstrate the utility of organotypic whole hemisphere brain slices as a platform to probe regional and developmental changes in the brain extracellular environment. We also leverage whole hemisphere brain slices to characterize the impact of cerebral ischemia on different regions of brain tissue. RESULTS Whole hemisphere brain slices taken from postnatal (P) day 10 and P17 rats retained viable, metabolically active cells through 14 days in vitro (DIV). Oxygen-glucose-deprivation (OGD), used to model a cerebral ischemic event in vivo, resulted in reduced slice metabolic activity and elevated cell death, regardless of slice age. Slices from P10 and P17 brains showed an oligodendrocyte and microglia-driven proliferative response after OGD exposure, higher than the proliferative response seen in DIV-matched normal control slices. Multiple particle tracking in oxygen-glucose-deprived brain slices revealed that oxygen-glucose-deprivation impacts the extracellular environment of brain tissue differently depending on brain age and brain region. In most instances, the extracellular space was most difficult to navigate immediately following insult, then gradually provided less hindrance to extracellular nanoparticle diffusion as time progressed. However, changes in diffusion were not universal across all brain regions and ages. CONCLUSIONS We demonstrate whole hemisphere brain slices from P10 and P17 rats can be cultured up to two weeks in vitro. These brain slices provide a viable platform for studying both normal physiological processes and injury associated mechanisms with control over brain age and region. Ex vivo OGD impacted cortical and striatal brain tissue differently, aligning with preexisting data generated in in vivo models. These data motivate the need to account for both brain region and age when investigating mechanisms of injury and designing potential therapies for cerebral ischemia.
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Affiliation(s)
- Michael McKenna
- Department of Chemical Engineering, University of Washington, 105 Benson Hall, Box 351750, Seattle, WA, 98195-1750, USA
| | - Jeremy R Filteau
- Department of Chemical Engineering, University of Washington, 105 Benson Hall, Box 351750, Seattle, WA, 98195-1750, USA
| | - Brendan Butler
- Department of Chemical Engineering, University of Washington, 105 Benson Hall, Box 351750, Seattle, WA, 98195-1750, USA
| | - Kenneth Sluis
- Department of Chemical Engineering, University of Washington, 105 Benson Hall, Box 351750, Seattle, WA, 98195-1750, USA
| | - Michael Chungyoun
- Department of Chemical Engineering, University of Washington, 105 Benson Hall, Box 351750, Seattle, WA, 98195-1750, USA
| | - Nels Schimek
- Department of Chemistry, University of Washington, Seattle, WA, USA
| | - Elizabeth Nance
- Department of Chemical Engineering, University of Washington, 105 Benson Hall, Box 351750, Seattle, WA, 98195-1750, USA. .,e-Science Institute, University of Washington, Seattle, WA, USA. .,Department of Bioengineering, University of Washington, Seattle, WA, USA.
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17
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Farrell C, Mumford P, Wiseman FK. Rodent Modeling of Alzheimer's Disease in Down Syndrome: In vivo and ex vivo Approaches. Front Neurosci 2022; 16:909669. [PMID: 35747206 PMCID: PMC9209729 DOI: 10.3389/fnins.2022.909669] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Accepted: 05/16/2022] [Indexed: 12/30/2022] Open
Abstract
There are an estimated 6 million people with Down syndrome (DS) worldwide. In developed countries, the vast majority of these individuals will develop Alzheimer's disease neuropathology characterized by the accumulation of amyloid-β (Aβ) plaques and tau neurofibrillary tangles within the brain, which leads to the early onset of dementia (AD-DS) and reduced life-expectancy. The mean age of onset of clinical dementia is ~55 years and by the age of 80, approaching 100% of individuals with DS will have a dementia diagnosis. DS is caused by trisomy of chromosome 21 (Hsa21) thus an additional copy of a gene(s) on the chromosome must cause the development of AD neuropathology and dementia. Indeed, triplication of the gene APP which encodes the amyloid precursor protein is sufficient and necessary for early onset AD (EOAD), both in people who have and do not have DS. However, triplication of other genes on Hsa21 leads to profound differences in neurodevelopment resulting in intellectual disability, elevated incidence of epilepsy and perturbations to the immune system. This different biology may impact on how AD neuropathology and dementia develops in people who have DS. Indeed, genes on Hsa21 other than APP when in three-copies can modulate AD-pathogenesis in mouse preclinical models. Understanding this biology better is critical to inform drug selection for AD prevention and therapy trials for people who have DS. Here we will review rodent preclinical models of AD-DS and how these can be used for both in vivo and ex vivo (cultured cells and organotypic slice cultures) studies to understand the mechanisms that contribute to the early development of AD in people who have DS and test the utility of treatments to prevent or delay the development of disease.
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18
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Aktories P, Petry P, Kierdorf K. Microglia in a Dish—Which Techniques Are on the Menu for Functional Studies? Front Cell Neurosci 2022; 16:908315. [PMID: 35722614 PMCID: PMC9204042 DOI: 10.3389/fncel.2022.908315] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2022] [Accepted: 05/11/2022] [Indexed: 12/12/2022] Open
Abstract
Microglia build the first line of defense in the central nervous system (CNS) and play central roles during development and homeostasis. Indeed, they serve a plethora of diverse functions in the CNS of which many are not yet fully described and more are still to be discovered. Research of the last decades unraveled an implication of microglia in nearly every neurodegenerative and neuroinflammatory disease, making it even more challenging to elucidate molecular mechanisms behind microglial functions and to modulate aberrant microglial behavior. To understand microglial functions and the underlying signaling machinery, many attempts were made to employ functional in vitro studies of microglia. However, the range of available cell culture models is wide and they come with different advantages and disadvantages for functional assays. Here we aim to provide a condensed summary of common microglia in vitro systems and discuss their potentials and shortcomings for functional studies in vitro.
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Affiliation(s)
- Philipp Aktories
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Philippe Petry
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Faculty of Biology, University of Freiburg, Freiburg, Germany
| | - Katrin Kierdorf
- Institute of Neuropathology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, Freiburg, Germany
- CIBSS-Centre for Integrative Biological Signalling Studies, University of Freiburg, Freiburg, Germany
- *Correspondence: Katrin Kierdorf
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19
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Stonedahl S, Leser JS, Clarke P, Tyler KL. Depletion of Microglia in an Ex Vivo Brain Slice Culture Model of West Nile Virus Infection Leads to Increased Viral Titers and Cell Death. Microbiol Spectr 2022; 10:e0068522. [PMID: 35412380 PMCID: PMC9045141 DOI: 10.1128/spectrum.00685-22] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Accepted: 03/21/2022] [Indexed: 01/03/2023] Open
Abstract
West Nile virus (WNV) is a major cause of viral encephalitis in the United States. WNV infection of the brain leads to neuroinflammation characterized by activation of microglia, the resident phagocytic cells of the central nervous system (CNS). In this study, depletion of CNS microglia using the CSF1R antagonist PLX5622 increased the viral load in the brain and decreased the survival of mice infected with WNV (strain TX02). PLX5622 was also used in ex vivo brain slice cultures (BSCs) to investigate the role of intrinsic neuroinflammatory responses during WNV infection. PLX5622 effectively depleted microglia (>90% depletion) from BSCs resulting in increased viral titers (3 to 4-fold increase in PLX5622-treated samples) and enhanced virus-induced caspase 3 activity and cell death. Microglia depletion did not result in widespread alterations in cytokine and chemokine production in either uninfected or WNV infected BSCs. The results of this study demonstrated how microglia contribute to limiting viral growth and preventing cell death in WNV infected BSCs but were not required for the cytokine/chemokine response to WNV infection. This study highlighted the importance of microglia in the protection from neuroinvasive WNV infection and demonstrated that microglia responses were independent of WNV-induced peripheral immune responses. IMPORTANCE WNV infections of the CNS are rare but can have devastating long-term effects. There are currently no vaccines or specific antiviral treatments, so a better understanding of the pathogenesis and immune response to this virus is crucial. Previous studies have shown microglia to be important for protection from WNV, but more work is needed to fully comprehend the impact these cells have on neuroinvasive WNV infections. This study used PLX5622 to eliminate microglia in an ex vivo brain slice culture (BSC) model to investigate the role of microglia during a WNV infection. The use of BSCs provided a system in which immune responses innate to the CNS could be studied without interference from peripheral immunity. This study will allow for a better understanding of the complex nature of microglia during viral infections and will likely impact the development of new therapeutics that target microglia.
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Affiliation(s)
- Sarah Stonedahl
- Department of Immunology and Microbiology, University of Colorado, Aurora, Colorado, USA
| | | | - Penny Clarke
- Department of Neurology, University of Colorado, Aurora, Colorado, USA
| | - Kenneth L. Tyler
- Department of Neurology, University of Colorado, Aurora, Colorado, USA
- Division of Infectious Disease, Department of Medicine, University of Colorado, Aurora, Colorado, USA
- Denver Veteran Affairs Medical Center, Aurora, Colorado, USA
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Bolton JL, Short AK, Othy S, Kooiker CL, Shao M, Gunn BG, Beck J, Bai X, Law SM, Savage JC, Lambert JJ, Belelli D, Tremblay MÈ, Cahalan MD, Baram TZ. Early stress-induced impaired microglial pruning of excitatory synapses on immature CRH-expressing neurons provokes aberrant adult stress responses. Cell Rep 2022; 38:110600. [PMID: 35354026 PMCID: PMC9014810 DOI: 10.1016/j.celrep.2022.110600] [Citation(s) in RCA: 52] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2021] [Revised: 02/10/2022] [Accepted: 03/08/2022] [Indexed: 12/12/2022] Open
Abstract
Several mental illnesses, characterized by aberrant stress reactivity, often arise after early-life adversity (ELA). However, it is unclear how ELA affects stress-related brain circuit maturation, provoking these enduring vulnerabilities. We find that ELA increases functional excitatory synapses onto stress-sensitive hypothalamic corticotropin-releasing hormone (CRH)-expressing neurons, resulting from disrupted developmental synapse pruning by adjacent microglia. Microglial process dynamics and synaptic element engulfment were attenuated in ELA mice, associated with deficient signaling of the microglial phagocytic receptor MerTK. Accordingly, selective chronic chemogenetic activation of ELA microglia increased microglial process dynamics and reduced excitatory synapse density to control levels. Notably, selective early-life activation of ELA microglia normalized adult acute and chronic stress responses, including stress-induced hormone secretion and behavioral threat responses, as well as chronic adrenal hypertrophy of ELA mice. Thus, microglial actions during development are powerful contributors to mechanisms by which ELA sculpts the connectivity of stress-regulating neurons, promoting vulnerability to stress and stress-related mental illnesses. Early-life adversity (ELA) promotes lifelong aberrant stress responses and vulnerability to mental illnesses. Bolton et al. identify poor dynamics and hypothalamic CRH neurons’ excitatory synapse pruning of ELA microglia, implicating microglial MerTK. Chronic chemogenetic activation of ELA microglia normalized process dynamics, synapse density, and adult hormonal and behavioral stress responses.
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Affiliation(s)
- Jessica L Bolton
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA.
| | - Annabel K Short
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA
| | - Shivashankar Othy
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA
| | - Cassandra L Kooiker
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA
| | - Manlin Shao
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA
| | - Benjamin G Gunn
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA; Division of Neuroscience, Medical Research Institute, Dundee University, Ninewells Hospital and Medical School, Dundee, UK
| | - Jaclyn Beck
- Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA
| | - Xinglong Bai
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA
| | - Stephanie M Law
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA
| | - Julie C Savage
- Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada; Axe Neurosciences, Centre de recherche du CHU de Québec, Québec City, QC, Canada
| | - Jeremy J Lambert
- Division of Neuroscience, Medical Research Institute, Dundee University, Ninewells Hospital and Medical School, Dundee, UK
| | - Delia Belelli
- Division of Neuroscience, Medical Research Institute, Dundee University, Ninewells Hospital and Medical School, Dundee, UK
| | - Marie-Ève Tremblay
- Département de Médecine Moléculaire, Université Laval, Québec City, QC, Canada; Axe Neurosciences, Centre de recherche du CHU de Québec, Québec City, QC, Canada
| | - Michael D Cahalan
- Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA
| | - Tallie Z Baram
- Department of Pediatrics, University of California, Irvine, Irvine, CA, USA; Department of Anatomy/Neurobiology, University of California, Irvine, Irvine, CA, USA; Department of Physiology and Biophysics, University of California, Irvine, Irvine, CA, USA.
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21
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Cadiz MP, Jensen TD, Sens JP, Zhu K, Song WM, Zhang B, Ebbert M, Chang R, Fryer JD. Culture shock: microglial heterogeneity, activation, and disrupted single-cell microglial networks in vitro. Mol Neurodegener 2022; 17:26. [PMID: 35346293 PMCID: PMC8962153 DOI: 10.1186/s13024-022-00531-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 03/09/2022] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Microglia, the resident immune cells of the brain, play a critical role in numerous diseases, but are a minority cell type and difficult to genetically manipulate in vivo with viral vectors and other approaches. Primary cultures allow a more controlled setting to investigate these cells, but morphological and transcriptional changes upon removal from their normal brain environment raise many caveats from in vitro studies. METHODS To investigate whether cultured microglia recapitulate in vivo microglial signatures, we used single-cell RNA sequencing (scRNAseq) to compare microglia freshly isolated from the brain to primary microglial cultures. We performed cell population discovery, differential expression analysis, and gene co-expression module analysis to compare signatures between in vitro and in vivo microglia. We constructed causal predictive network models of transcriptional regulators from the scRNAseq data and identified a set of potential key drivers of the cultured phenotype. To validate this network analysis, we knocked down two of these key drivers, C1qc and Prdx1, in primary cultured microglia and quantified changes in microglial activation markers. RESULTS We found that, although often assumed to be a relatively homogenous population of cells in culture, in vitro microglia are a highly heterogeneous population consisting of distinct subpopulations of cells with transcriptional profiles reminiscent of macrophages and monocytes, and are marked by transcriptional programs active in neurodegeneration and other disease states. We found that microglia in vitro presented transcriptional activation of a set of "culture shock genes" not found in freshly isolated microglia, characterized by strong upregulation of disease-associated genes including Apoe, Lyz2, and Spp1, and downregulation of homeostatic microglial markers, including Cx3cr1, P2ry12, and Tmem119. Finally, we found that cultured microglia prominently alter their transcriptional machinery modulated by key drivers from the homeostatic to activated phenotype. Knockdown of one of these drivers, C1qc, resulted in downregulation of microglial activation genes Lpl, Lyz2, and Ccl4. CONCLUSIONS Overall, our data suggest that when removed from their in vivo home environment, microglia suffer a severe case of "culture shock", drastically modulating their transcriptional regulatory network state from homeostatic to activated through upregulation of modules of culture-specific genes. Consequently, cultured microglia behave as a disparate cell type that does not recapitulate the homeostatic signatures of microglia in vivo. Finally, our predictive network model discovered potential key drivers that may convert activated microglia back to their homeostatic state, allowing for more accurate representation of in vivo states in culture. Knockdown of key driver C1qc partially attenuated microglial activation in vitro, despite C1qc being only weakly upregulated in culture. This suggests that even genes that are not strongly differentially expressed across treatments or preparations may drive downstream transcriptional changes in culture.
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Affiliation(s)
- Mika P. Cadiz
- Department of Neuroscience, Mayo Clinic, Scottsdale, AZ 85259 USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Scottsdale, AZ 85259 USA
| | - Tanner D. Jensen
- Department of Neuroscience, Mayo Clinic, Scottsdale, AZ 85259 USA
| | - Jonathon P. Sens
- Department of Neuroscience, Mayo Clinic, Scottsdale, AZ 85259 USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Scottsdale, AZ 85259 USA
| | - Kuixi Zhu
- Department of Neurology, University of Arizona, Tucson, AZ 85721 USA
| | - Won-Min Song
- Department of Genetics & Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
| | - Bin Zhang
- Department of Genetics & Genomic Sciences, Mount Sinai Center for Transformative Disease Modeling, Icahn School of Medicine at Mount Sinai, New York, NY 10029 USA
| | - Mark Ebbert
- Sanders-Brown Center on Aging, Biomedical Informatics, and Department of Neuroscience, University of Kentucky, Lexington, KY 40536 USA
| | - Rui Chang
- Department of Neurology, University of Arizona, Tucson, AZ 85721 USA
| | - John D. Fryer
- Department of Neuroscience, Mayo Clinic, Scottsdale, AZ 85259 USA
- Neuroscience Graduate Program, Mayo Clinic Graduate School of Biomedical Sciences, Scottsdale, AZ 85259 USA
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22
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Raj A, Kaushal A, Datta I. Impact of monomeric and aggregated wild-type and A30P/A53T double-mutant α-synuclein on antioxidant mechanism and glutamate metabolic profile of cultured astrocytes. J Neurosci Res 2021; 100:681-706. [PMID: 34904280 DOI: 10.1002/jnr.24994] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 10/28/2021] [Accepted: 11/15/2021] [Indexed: 12/17/2022]
Abstract
Serving as a source of glutathione and up-taking and metabolizing glutamate are the primary supportive role of astrocytes for the adjacent neurons. Despite the clear physical association between astrocytes and α-synuclein, the effect of extracellular α-synuclein on these astrocytic functions has not yet been elucidated. Hence, we aim to assess the effect of various forms of α-synuclein on antioxidant mechanism and glutamate metabolism. Wild-type and A53T/A30P double-mutant α-synuclein, both in monomeric and aggregated forms, were added extracellularly to media of midbrain rat astrocyte culture, with their survival, oxidative, and nitrative stress, glutathione and glutamate content, expression of enzymes associated with oxidative stress and glutamate metabolism, glutamate and glutathione transporters being assessed along with the association/engulfment of these peptides by astrocytes. A30P/A53T peptide associated more with astrocytes, and low-extracellular K+ concentration showed prominent reduction in the engulfment of the monomeric forms, suggesting that the association of the aggregated forms was greater with the membrane. The peptide-associated astrocytes showed lower survival and increased oxidative stress generation, owing to the decrease in nuclear localization of Nrf2 and increase in iNOS, and further aggravated by the decrease in glutathione content and related enzymes like glutathione synthetase, glutathione peroxidase, and glutathione reductase. Glutamate uptake increased in aggregate-treated cells due to the increase in GLAST1 expression, de novo synthesis of glutamate by pyruvate carboxylase, and/or glutamine synthase, bolstered by the differential glutamate dehydrogenase enzyme activity. We thus show for the first time that extracellular α-synuclein exposure leads to astrocytic dysfunction with respect to the antioxidant mechanism and glutamate metabolic profile. The impact was higher in the case of the aggregated and mutated peptide, with the highest dysfunction for the mutant aggregated α-synuclein treatment.
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Affiliation(s)
- Aishwarya Raj
- Department of Biophysics, National Institute of Mental Health and Neurosciences, Institute of National Importance, Bengaluru, India
| | - Alka Kaushal
- Department of Biophysics, National Institute of Mental Health and Neurosciences, Institute of National Importance, Bengaluru, India
| | - Indrani Datta
- Department of Biophysics, National Institute of Mental Health and Neurosciences, Institute of National Importance, Bengaluru, India
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23
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Wood TR, Hildahl K, Helmbrecht H, Corry KA, Moralejo DH, Kolnik SE, Prater KE, Juul SE, Nance E. A ferret brain slice model of oxygen–glucose deprivation captures regional responses to perinatal injury and treatment associated with specific microglial phenotypes. Bioeng Transl Med 2021; 7:e10265. [PMID: 35600642 PMCID: PMC9115703 DOI: 10.1002/btm2.10265] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 10/28/2021] [Accepted: 10/30/2021] [Indexed: 12/14/2022] Open
Abstract
Organotypic brain slice models are an ideal technological platform to investigate therapeutic options for hypoxic‐ischemic (HI) brain injury, a leading cause of morbidity and mortality in neonates. The brain exhibits regional differences in the response to HI injury in vivo. This can be modeled using organotypic brain slices, which maintain three‐dimensional regional structures and reflect the regional differences in injury response. Here, we developed an organotypic whole hemisphere (OWH) slice culture model of HI injury using the gyrencephalic ferret brain at a developmental stage equivalent to a full‐term human infant in order to better probe region‐specific cellular responses to injury. Each slice encompassed the cortex, corpus callosum, subcortical white matter, hippocampus, basal ganglia, and thalamus. Regional responses to treatment with either erythropoietin (Epo) or the ketone body acetoacetate (AcAc) were highly heterogenous. While both treatments suppressed global injury responses and oxidative stress, significant neuroprotection was only seen in a subset of regions, with others displaying no response or potential exacerbation of injury. Similar regional heterogeneity was seen in the morphology and response of microglia to injury and treatment, which mirrored those seen after injury in vivo. Within each region, machine‐learning‐based classification of microglia morphological shifts in response to injury predicted the neuroprotective response to each therapy, with different morphologies associated with different treatment responses. This suggests that the ferret OWH slice culture model provides a platform for examining regional responses to injury in the gyrencephalic brain, as well as for screening combinations of therapeutics to provide global neuroprotection after injury.
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Affiliation(s)
- Thomas R. Wood
- Department of Pediatrics, Division of Neonatology University of Washington Seattle Washington USA
- Center on Human Development and Disability University of Washington Seattle Washington USA
| | - Kate Hildahl
- Department of Chemical Engineering University of Washington Seattle Washington USA
| | - Hawley Helmbrecht
- Department of Chemical Engineering University of Washington Seattle Washington USA
| | - Kylie A. Corry
- Department of Pediatrics, Division of Neonatology University of Washington Seattle Washington USA
| | - Daniel H. Moralejo
- Department of Pediatrics, Division of Neonatology University of Washington Seattle Washington USA
| | - Sarah E. Kolnik
- Department of Pediatrics, Division of Neonatology University of Washington Seattle Washington USA
| | | | - Sandra E. Juul
- Department of Pediatrics, Division of Neonatology University of Washington Seattle Washington USA
- Center on Human Development and Disability University of Washington Seattle Washington USA
| | - Elizabeth Nance
- Center on Human Development and Disability University of Washington Seattle Washington USA
- Department of Chemical Engineering University of Washington Seattle Washington USA
- Department of Bioengineering University of Washington Seattle Washington USA
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24
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Shaker T, Chattopadhyaya B, Amilhon B, Cristo GD, Weil AG. Transduction of inflammation from peripheral immune cells to the hippocampus induces neuronal hyperexcitability mediated by Caspase-1 activation. Neurobiol Dis 2021; 160:105535. [PMID: 34673150 DOI: 10.1016/j.nbd.2021.105535] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 07/30/2021] [Accepted: 10/17/2021] [Indexed: 01/20/2023] Open
Abstract
BACKGROUND Recent studies report infiltration of peripheral blood mononuclear cells (PBMCs) into the central nervous system (CNS) in epileptic disorders, suggestive of a potential contribution of PBMC extravasation to the generation of seizures. Nevertheless, the underlying mechanisms involved in PBMC infiltrates promoting neuronal predisposition to ictogenesis remain unclear. Therefore, we developed an in vitro model mimicking infiltration of activated PBMCs into the brain in order to investigate potential transduction of inflammatory signals from PBMCs to the CNS. METHODS To establish our model, we first extracted PBMCs from rat spleen, then, immunologically primed PBMCs with lipopolysaccharide (LPS), followed by further activation with nigericin. Thereafter, we co-cultured these activated PBMCs with organotypic cortico-hippocampal brain slice cultures (OCHSCs) derived from the same rat, and compared PBMC-OCHSC co-cultures to OCHSCs exposed to PBMCs in the culture media. We further targeted a potential molecular pathway underlying transduction of peripheral inflammation to OCHSCs by incubating OCHSCs with the Caspase-1 inhibitor VX-765 prior to co-culturing PBMCs with OCHSCs. After 24 h, we analyzed inflammation markers in the cortex and the hippocampus using semiquantitative immunofluorescence. In addition, we analyzed neuronal activity by whole-cell patch-clamp recordings in cortical layer II/III and hippocampal CA1 pyramidal neurons. RESULTS In the cortex, co-culturing immunoreactive PBMCs treated with LPS + nigericin on top of OCHSCs upregulated inflammatory markers and enhanced neuronal excitation. In contrast, no excitability changes were detected after adding primed PBMCs (i.e. treated with LPS only), to OCHSCs. Strikingly, in the hippocampus, both immunoreactive and primed PBMCs elicited similar pro-inflammatory and pro-excitatory effects. However, when immunoreactive and primed PBMCs were cultured in the media separately from OCHSCs, only immunoreactive PBMCs gave rise to neuroinflammation and hyperexcitability in the hippocampus, whereas primed PBMCs failed to produce any significant changes. Finally, VX-765 application to OCHSCs, co-cultured with either immunoreactive or primed PBMCs, prevented neuroinflammation and hippocampal hyperexcitability in OCHSCs. CONCLUSIONS Our study shows a higher susceptibility of the hippocampus to peripheral inflammation as compared to the cortex, mediated via Caspase-1-dependent signaling pathways. Thus, our findings suggest that Caspase-1 inhibition may potentially provide therapeutic benefits during hippocampal neuroinflammation and hyperexcitability secondary to peripheral innate immunity.
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Affiliation(s)
- Tarek Shaker
- Université de Montréal, Montréal, Québec H3C 3J7, Canada; CHU Sainte-Justine Research Centre, Montréal, Québec H3T 1C5, Canada.
| | | | - Bénédicte Amilhon
- Université de Montréal, Montréal, Québec H3C 3J7, Canada; CHU Sainte-Justine Research Centre, Montréal, Québec H3T 1C5, Canada
| | - Graziella Di Cristo
- Université de Montréal, Montréal, Québec H3C 3J7, Canada; CHU Sainte-Justine Research Centre, Montréal, Québec H3T 1C5, Canada
| | - Alexander G Weil
- Université de Montréal, Montréal, Québec H3C 3J7, Canada; CHU Sainte-Justine Research Centre, Montréal, Québec H3T 1C5, Canada.
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25
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Alexaki VI. The Impact of Obesity on Microglial Function: Immune, Metabolic and Endocrine Perspectives. Cells 2021; 10:cells10071584. [PMID: 34201844 PMCID: PMC8307603 DOI: 10.3390/cells10071584] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/18/2021] [Accepted: 06/22/2021] [Indexed: 02/06/2023] Open
Abstract
Increased life expectancy in combination with modern life style and high prevalence of obesity are important risk factors for development of neurodegenerative diseases. Neuroinflammation is a feature of neurodegenerative diseases, and microglia, the innate immune cells of the brain, are central players in it. The present review discusses the effects of obesity, chronic peripheral inflammation and obesity-associated metabolic and endocrine perturbations, including insulin resistance, dyslipidemia and increased glucocorticoid levels, on microglial function.
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Affiliation(s)
- Vasileia Ismini Alexaki
- Institute for Clinical Chemistry and Laboratory Medicine, University Clinic Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, 01307 Dresden, Germany
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26
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Monitoring and Modulating Inflammation-Associated Alterations in Synaptic Plasticity: Role of Brain Stimulation and the Blood-Brain Interface. Biomolecules 2021; 11:biom11030359. [PMID: 33652912 PMCID: PMC7996828 DOI: 10.3390/biom11030359] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 02/18/2021] [Accepted: 02/20/2021] [Indexed: 12/20/2022] Open
Abstract
Inflammation of the central nervous system can be triggered by endogenous and exogenous stimuli such as local or systemic infection, trauma, and stroke. In addition to neurodegeneration and cell death, alterations in physiological brain functions are often associated with neuroinflammation. Robust experimental evidence has demonstrated that inflammatory cytokines affect the ability of neurons to express plasticity. It has been well-established that inflammation-associated alterations in synaptic plasticity contribute to the development of neuropsychiatric symptoms. Nevertheless, diagnostic approaches and interventional strategies to restore inflammatory deficits in synaptic plasticity are limited. Here, we review recent findings on inflammation-associated alterations in synaptic plasticity and the potential role of the blood–brain interface, i.e., the blood–brain barrier, in modulating synaptic plasticity. Based on recent findings indicating that brain stimulation promotes plasticity and modulates vascular function, we argue that clinically employed non-invasive brain stimulation techniques, such as transcranial magnetic stimulation, could be used for monitoring and modulating inflammation-induced alterations in synaptic plasticity.
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