101
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Freel BA, Kelvington BA, Sengupta S, Mukherjee M, Francis KR. Sterol dysregulation in Smith-Lemli-Opitz syndrome causes astrocyte immune reactivity through microglia crosstalk. Dis Model Mech 2022; 15:dmm049843. [PMID: 36524414 PMCID: PMC10655813 DOI: 10.1242/dmm.049843] [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: 08/15/2022] [Accepted: 11/17/2022] [Indexed: 12/23/2022] Open
Abstract
Owing to the need for de novo cholesterol synthesis and cholesterol-enriched structures within the nervous system, cholesterol homeostasis is critical to neurodevelopment. Diseases caused by genetic disruption of cholesterol biosynthesis, such as Smith-Lemli-Opitz syndrome, which is caused by mutations in 7-dehydrocholesterol reductase (DHCR7), frequently result in broad neurological deficits. Although astrocytes regulate multiple neural processes ranging from cell migration to network-level communication, immunological activation of astrocytes is a hallmark pathology in many diseases. However, the impact of DHCR7 on astrocyte function and immune activation remains unknown. We demonstrate that astrocytes from Dhcr7 mutant mice display hallmark signs of reactivity, including increased expression of glial fibrillary acidic protein (GFAP) and cellular hypertrophy. Transcript analyses demonstrate extensive Dhcr7 astrocyte immune activation, hyper-responsiveness to glutamate stimulation and altered calcium flux. We further determine that the impacts of Dhcr7 are not astrocyte intrinsic but result from non-cell-autonomous effects of microglia. Our data suggest that astrocyte-microglia crosstalk likely contributes to the neurological phenotypes observed in disorders of cholesterol biosynthesis. Additionally, these data further elucidate a role for cholesterol metabolism within the astrocyte-microglia immune axis, with possible implications in other neurological diseases.
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Affiliation(s)
- Bethany A. Freel
- Basic Biomedical Sciences, University of South Dakota, Vermillion, SD 57069, USA
- Cellular Therapies and Stem Cell Biology Group, Sanford Research, Sioux Falls, SD 57104, USA
| | - Benjamin A. Kelvington
- Cellular Therapies and Stem Cell Biology Group, Sanford Research, Sioux Falls, SD 57104, USA
| | - Sonali Sengupta
- Cellular Therapies and Stem Cell Biology Group, Sanford Research, Sioux Falls, SD 57104, USA
| | - Malini Mukherjee
- Functional Genomics and Bioinformatics Core, Sanford Research, Sioux Falls, SD 57104, USA
| | - Kevin R. Francis
- Cellular Therapies and Stem Cell Biology Group, Sanford Research, Sioux Falls, SD 57104, USA
- Department of Pediatrics, Sanford School of Medicine, University of South Dakota, Sioux Falls, SD 57105, USA
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102
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Requie LM, Gómez-Gonzalo M, Speggiorin M, Managò F, Melone M, Congiu M, Chiavegato A, Lia A, Zonta M, Losi G, Henriques VJ, Pugliese A, Pacinelli G, Marsicano G, Papaleo F, Muntoni AL, Conti F, Carmignoto G. Astrocytes mediate long-lasting synaptic regulation of ventral tegmental area dopamine neurons. Nat Neurosci 2022; 25:1639-1650. [PMID: 36396976 DOI: 10.1038/s41593-022-01193-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Accepted: 10/03/2022] [Indexed: 11/18/2022]
Abstract
The plasticity of glutamatergic transmission in the ventral tegmental area (VTA) represents a fundamental mechanism in the modulation of dopamine neuron burst firing and phasic dopamine release at target regions. These processes encode basic behavioral responses, including locomotor activity, learning and motivated behaviors. Here we describe a hitherto unidentified mechanism of long-term synaptic plasticity in mouse VTA. We found that the burst firing in individual dopamine neurons induces a long-lasting potentiation of excitatory synapses on adjacent dopamine neurons that crucially depends on Ca2+ elevations in astrocytes, mediated by endocannabinoid CB1 and dopamine D2 receptors co-localized at the same astrocytic process, and activation of pre-synaptic metabotropic glutamate receptors. Consistent with these findings, selective in vivo activation of astrocytes increases the burst firing of dopamine neurons in the VTA and induces locomotor hyperactivity. Astrocytes play, therefore, a key role in the modulation of VTA dopamine neuron functional activity.
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Affiliation(s)
- Linda Maria Requie
- Neuroscience Institute, Section of Padova, National Research Council (CNR) and Department of Biomedical Sciences, Università degli Studi di Padova, Padova, Italy
| | - Marta Gómez-Gonzalo
- Neuroscience Institute, Section of Padova, National Research Council (CNR) and Department of Biomedical Sciences, Università degli Studi di Padova, Padova, Italy.
| | - Michele Speggiorin
- Neuroscience Institute, Section of Padova, National Research Council (CNR) and Department of Biomedical Sciences, Università degli Studi di Padova, Padova, Italy
| | - Francesca Managò
- Genetics of Cognition Laboratory, Neuroscience Area, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Marcello Melone
- Department of Experimental and Clinical Medicine, Section of Neuroscience & Cell Biology, Università Politecnica delle Marche, and Center for Neurobiology of Aging, Ancona, Italy
| | - Mauro Congiu
- Department of Biomedical Sciences, Division of Neuroscience and Clinical Pharmacology, Università degli Studi di Cagliari, Cagliari, Italy.,Neuroscience Institute, Section of Cagliari, National Research Council (CNR), Cagliari, Italy
| | - Angela Chiavegato
- Neuroscience Institute, Section of Padova, National Research Council (CNR) and Department of Biomedical Sciences, Università degli Studi di Padova, Padova, Italy
| | - Annamaria Lia
- Neuroscience Institute, Section of Padova, National Research Council (CNR) and Department of Biomedical Sciences, Università degli Studi di Padova, Padova, Italy
| | - Micaela Zonta
- Neuroscience Institute, Section of Padova, National Research Council (CNR) and Department of Biomedical Sciences, Università degli Studi di Padova, Padova, Italy
| | - Gabriele Losi
- Neuroscience Institute, Section of Padova, National Research Council (CNR) and Department of Biomedical Sciences, Università degli Studi di Padova, Padova, Italy.,Nanoscienze Institute, National Research Council (CNR), Modena, Italy
| | - Vanessa Jorge Henriques
- Neuroscience Institute, Section of Padova, National Research Council (CNR) and Department of Biomedical Sciences, Università degli Studi di Padova, Padova, Italy
| | - Arianna Pugliese
- Department of Experimental and Clinical Medicine, Section of Neuroscience & Cell Biology, Università Politecnica delle Marche, and Center for Neurobiology of Aging, Ancona, Italy
| | - Giada Pacinelli
- Genetics of Cognition Laboratory, Neuroscience Area, Istituto Italiano di Tecnologia (IIT), Genova, Italy.,Padova Neuroscience Center (PNC), University of Padova, Padova, Italy
| | - Giovanni Marsicano
- University of Bordeaux and Interdisciplinary Institute for Neuroscience (CNRS), Bordeaux, France
| | - Francesco Papaleo
- Genetics of Cognition Laboratory, Neuroscience Area, Istituto Italiano di Tecnologia (IIT), Genova, Italy
| | - Anna Lisa Muntoni
- Neuroscience Institute, Section of Cagliari, National Research Council (CNR), Cagliari, Italy
| | - Fiorenzo Conti
- Department of Experimental and Clinical Medicine, Section of Neuroscience & Cell Biology, Università Politecnica delle Marche, and Center for Neurobiology of Aging, Ancona, Italy
| | - Giorgio Carmignoto
- Neuroscience Institute, Section of Padova, National Research Council (CNR) and Department of Biomedical Sciences, Università degli Studi di Padova, Padova, Italy.
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103
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Sugisaki E, Fukushima Y, Nakajima N, Aihara T. The dependence of acetylcholine on dynamic changes in the membrane potential and an action potential during spike timing-dependent plasticity induction in the hippocampus. Eur J Neurosci 2022; 56:5972-5986. [PMID: 36164804 DOI: 10.1111/ejn.15832] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 09/01/2022] [Accepted: 09/16/2022] [Indexed: 12/29/2022]
Abstract
The hippocampus is an important area for memory encoding and retrieval and is the location of spike timing-dependent plasticity (STDP), a basic phenomenon of learning and memory. STDP is facilitated if acetylcholine (ACh) is released from cholinergic neurons during attentional processes. However, it is unclear how ACh influences postsynaptic changes during STDP induction and determines the STDP magnitude. To address these issues, we obtained patch clamp recordings from CA1 pyramidal neurons to evaluate the postsynaptic changes during stimuli injection in Schaffer collaterals by quantifying baseline amplitudes (i.e., the lowest values elicited by paired pulses comprising STDP stimuli) and action potentials. The results showed that baseline amplitudes were elevated if eserine was applied in the presence of picrotoxin. In addition, muscarinic ACh receptors (mAChRs) contributed more to the baseline amplitude elevation than nicotinic AChRs (nAChRs). Moreover, the magnitude of the STDP depended on the magnitude of the baseline amplitude. However, in the absence of picrotoxin, baseline amplitudes were balanced, regardless of the ACh concentration, resulting in a similar magnitude of the STDP, except under the nAChR alone-activated condition, which showed a larger STDP and lower baseline amplitude induction. This was due to broadened widths of action potentials. These results suggest that activation of mAChRs and nAChRs, which are effective for baseline amplitudes and action potentials, respectively, plays an important role in postsynaptic changes during memory consolidation.
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Affiliation(s)
- Eriko Sugisaki
- Brain Science Institute, Tamagawa University, Tokyo, Japan
| | - Yasuhiro Fukushima
- Brain Science Institute, Tamagawa University, Tokyo, Japan.,Kawasaki University of Medical Welfare, Okayama, Japan
| | - Naoki Nakajima
- Graduated School of Engineering, Tamagawa University, Tokyo, Japan
| | - Takeshi Aihara
- Brain Science Institute, Tamagawa University, Tokyo, Japan
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104
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Calcium complexes of oxicams: new dimensions in rheumatoid arthritis treatment. Future Med Chem 2022; 14:1771-1788. [PMID: 36519430 DOI: 10.4155/fmc-2022-0032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Various metals have been complexed with drugs to improve their cellular impact. Inflammatory diseases like rheumatoid arthritis (RA) are characterized by unbalanced production of proinflammatory cytokines (PICs) and prostaglandins with decreased levels of vitamin D and calcium. The inflammation can be suppressed through targeting the formation of PICs or related enzymes by various treatment strategies that involve the use of corticosteroids, disease-modifying antirheumatic drugs and NSAIDs. We present a detailed review on the impact of calcium complexes of oxicams as an advanced treatment strategy for RA. The calcium complexes demonstrate promising capabilities to cure the disease, improve the strength of bones and suppress PICs in RA.
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105
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Dewdney B, Ursich L, Fletcher EV, Johns TG. Anoctamins and Calcium Signalling: An Obstacle to EGFR Targeted Therapy in Glioblastoma? Cancers (Basel) 2022; 14:cancers14235932. [PMID: 36497413 PMCID: PMC9740065 DOI: 10.3390/cancers14235932] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2022] [Revised: 11/28/2022] [Accepted: 11/28/2022] [Indexed: 12/05/2022] Open
Abstract
Glioblastoma is the most common form of high-grade glioma in adults and has a poor survival rate with very limited treatment options. There have been no significant advancements in glioblastoma treatment in over 30 years. Epidermal growth factor receptor is upregulated in most glioblastoma tumours and, therefore, has been a drug target in recent targeted therapy clinical trials. However, while many inhibitors and antibodies for epidermal growth factor receptor have demonstrated promising anti-tumour effects in preclinical models, they have failed to improve outcomes for glioblastoma patients in clinical trials. This is likely due to the highly plastic nature of glioblastoma tumours, which results in therapeutic resistance. Ion channels are instrumental in the development of many cancers and may regulate cellular plasticity in glioblastoma. This review will explore the potential involvement of a class of calcium-activated chloride channels called anoctamins in brain cancer. We will also discuss the integrated role of calcium channels and anoctamins in regulating calcium-mediated signalling pathways, such as epidermal growth factor signalling, to promote brain cancer cell growth and migration.
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Affiliation(s)
- Brittany Dewdney
- Cancer Centre, Telethon Kids Institute, Perth, WA 6009, Australia
- Centre for Child Health Research, University of Western Australia, Perth, WA 6009, Australia
- Correspondence: ; Tel.: +61-8-6319-1023
| | - Lauren Ursich
- Cancer Centre, Telethon Kids Institute, Perth, WA 6009, Australia
- School of Biomedical Sciences, University of Western Australia, Perth, WA 6009, Australia
| | - Emily V. Fletcher
- Cancer Centre, Telethon Kids Institute, Perth, WA 6009, Australia
- Centre for Child Health Research, University of Western Australia, Perth, WA 6009, Australia
| | - Terrance G. Johns
- Cancer Centre, Telethon Kids Institute, Perth, WA 6009, Australia
- Centre for Child Health Research, University of Western Australia, Perth, WA 6009, Australia
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106
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Wu Y, Tang Z, Zhang J, Wang Y, Liu S. Restoration of spinal cord injury: From endogenous repairing process to cellular therapy. Front Cell Neurosci 2022; 16:1077441. [PMID: 36523818 PMCID: PMC9744968 DOI: 10.3389/fncel.2022.1077441] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2022] [Accepted: 11/08/2022] [Indexed: 09/26/2023] Open
Abstract
Spinal cord injury (SCI) disrupts neurological pathways and impacts sensory, motor, and autonomic nerve function. There is no effective treatment for SCI currently. Numerous endogenous cells, including astrocytes, macrophages/microglia, and oligodendrocyte, are involved in the histological healing process following SCI. By interfering with cells during the SCI repair process, some advancements in the therapy of SCI have been realized. Nevertheless, the endogenous cell types engaged in SCI repair and the current difficulties these cells confront in the therapy of SCI are poorly defined, and the mechanisms underlying them are little understood. In order to better understand SCI and create new therapeutic strategies and enhance the clinical translation of SCI repair, we have comprehensively listed the endogenous cells involved in SCI repair and summarized the six most common mechanisms involved in SCI repair, including limiting the inflammatory response, protecting the spared spinal cord, enhancing myelination, facilitating neovascularization, producing neurotrophic factors, and differentiating into neural/colloidal cell lines.
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Affiliation(s)
| | | | | | | | - Shengwen Liu
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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107
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Arnst N, Redolfi N, Lia A, Bedetta M, Greotti E, Pizzo P. Mitochondrial Ca 2+ Signaling and Bioenergetics in Alzheimer's Disease. Biomedicines 2022; 10:3025. [PMID: 36551781 PMCID: PMC9775979 DOI: 10.3390/biomedicines10123025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 11/17/2022] [Accepted: 11/22/2022] [Indexed: 11/25/2022] Open
Abstract
Alzheimer's disease (AD) is a hereditary and sporadic neurodegenerative illness defined by the gradual and cumulative loss of neurons in specific brain areas. The processes that cause AD are still under investigation and there are no available therapies to halt it. Current progress puts at the forefront the "calcium (Ca2+) hypothesis" as a key AD pathogenic pathway, impacting neuronal, astrocyte and microglial function. In this review, we focused on mitochondrial Ca2+ alterations in AD, their causes and bioenergetic consequences in neuronal and glial cells, summarizing the possible mechanisms linking detrimental mitochondrial Ca2+ signals to neuronal death in different experimental AD models.
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Affiliation(s)
- Nikita Arnst
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
| | - Nelly Redolfi
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
| | - Annamaria Lia
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), 35131 Padua, Italy
| | - Martina Bedetta
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
| | - Elisa Greotti
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), 35131 Padua, Italy
- Padova Neuroscience Center (PNC), University of Padova, 35131 Padua, Italy
| | - Paola Pizzo
- Department of Biomedical Sciences, University of Padova, 35131 Padua, Italy
- Neuroscience Institute, Italian National Research Council (CNR), 35131 Padua, Italy
- Study Centre for Neurodegeneration (CESNE), University of Padova, 35131 Padua, Italy
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108
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Meng J, Zhang J, Fang J, Li M, Ding H, Zhang W, Chen C. Dynamic inflammatory changes of the neurovascular units after ischemic stroke. Brain Res Bull 2022; 190:140-151. [DOI: 10.1016/j.brainresbull.2022.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Revised: 07/21/2022] [Accepted: 10/04/2022] [Indexed: 11/16/2022]
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109
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Badia-Soteras A, Heistek TS, Kater MSJ, Mak A, Negrean A, van den Oever MC, Mansvelder HD, Khakh BS, Min R, Smit AB, Verheijen MHG. Retraction of Astrocyte Leaflets From the Synapse Enhances Fear Memory. Biol Psychiatry 2022:S0006-3223(22)01705-X. [PMID: 36702661 DOI: 10.1016/j.biopsych.2022.10.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 10/07/2022] [Accepted: 10/20/2022] [Indexed: 01/28/2023]
Abstract
BACKGROUND The formation and retrieval of fear memories depends on orchestrated synaptic activity of neuronal ensembles within the hippocampus, and it is becoming increasingly evident that astrocytes residing in the environment of these synapses play a central role in shaping cellular memory representations. Astrocyte distal processes, known as leaflets, fine-tune synaptic activity by clearing neurotransmitters and limiting glutamate diffusion. However, how astroglial synaptic coverage contributes to mnemonic processing of fearful experiences remains largely unknown. METHODS We used electron microscopy to observe changes in astroglial coverage of hippocampal synapses during consolidation of fear memory in mice. To manipulate astroglial synaptic coverage, we depleted ezrin, an integral leaflet-structural protein, from hippocampal astrocytes using CRISPR (clustered regularly interspaced short palindromic repeats)/Cas9 gene editing. Next, a combination of Föster resonance energy transfer analysis, genetically encoded glutamate sensors, and whole-cell patch-clamp recordings was used to determine whether the proximity of astrocyte leaflets to the synapse is critical for synaptic integrity and function. RESULTS We found that consolidation of a recent fear memory is accompanied by a transient retraction of astrocyte leaflets from hippocampal synapses and increased activation of NMDA receptors. Accordingly, astrocyte-specific depletion of ezrin resulted in shorter astrocyte leaflets and reduced astrocyte contact with the synaptic cleft, which consequently boosted extrasynaptic glutamate diffusion and NMDA receptor activation. Importantly, after fear conditioning, these cellular phenotypes translated to increased retrieval-evoked activation of CA1 pyramidal neurons and enhanced fear memory expression. CONCLUSIONS Together, our data show that withdrawal of astrocyte leaflets from the synaptic cleft is an experience-induced, temporally regulated process that gates the strength of fear memories.
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Affiliation(s)
- Aina Badia-Soteras
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Tim S Heistek
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Mandy S J Kater
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Aline Mak
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Adrian Negrean
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Michel C van den Oever
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Huibert D Mansvelder
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Baljit S Khakh
- Department of Physiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California; Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California
| | - Rogier Min
- Department of Integrative Neurophysiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands; Department of Child Neurology, Emma Children's Hospital, Amsterdam University Medical Centers, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - August B Smit
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands
| | - Mark H G Verheijen
- Department of Molecular and Cellular Neuroscience, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, Amsterdam, the Netherlands.
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110
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Miyata S. Glial functions in the blood-brain communication at the circumventricular organs. Front Neurosci 2022; 16:991779. [PMID: 36278020 PMCID: PMC9583022 DOI: 10.3389/fnins.2022.991779] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2022] [Accepted: 09/20/2022] [Indexed: 11/13/2022] Open
Abstract
The circumventricular organs (CVOs) are located around the brain ventricles, lack a blood-brain barrier (BBB) and sense blood-derived molecules. This review discusses recent advances in the importance of CVO functions, especially glial cells transferring periphery inflammation signals to the brain. The CVOs show size-limited vascular permeability, allowing the passage of molecules with molecular weight <10,000. This indicates that the lack of an endothelial cell barrier does not mean the free movement of blood-derived molecules into the CVO parenchyma. Astrocytes and tanycytes constitute a dense barrier at the distal CVO subdivision, preventing the free diffusion of blood-derived molecules into neighboring brain regions. Tanycytes in the CVOs mediate communication between cerebrospinal fluid and brain parenchyma via transcytosis. Microglia and macrophages of the CVOs are essential for transmitting peripheral information to other brain regions via toll-like receptor 2 (TLR2). Inhibition of TLR2 signaling or depletion of microglia and macrophages in the brain eliminates TLR2-dependent inflammatory responses. In contrast to TLR2, astrocytes and tanycytes in the CVOs of the brain are crucial for initiating lipopolysaccharide (LPS)-induced inflammatory responses via TLR4. Depletion of microglia and macrophages augments LPS-induced fever and chronic sickness responses. Microglia and macrophages in the CVOs are continuously activated, even under normal physiological conditions, as they exhibit activated morphology and express the M1/M2 marker proteins. Moreover, the microglial proliferation occurs in various regions, such as the hypothalamus, medulla oblongata, and telencephalon, with a marked increase in the CVOs, due to low-dose LPS administration, and after high-dose LPS administration, proliferation is seen in most brain regions, except for the cerebral cortex and hippocampus. A transient increase in the microglial population is beneficial during LPS-induced inflammation for attenuating sickness response. Transient receptor potential receptor vanilloid 1 expressed in astrocytes and tanycytes of the CVOs is responsible for thermoregulation upon exposure to a warm environment less than 37°C. Alternatively, Nax expressed in astrocytes and tanycytes of the CVOs is crucial for maintaining body fluid homeostasis. Thus, recent findings indicate that glial cells in the brain CVOs are essential for initiating neuroinflammatory responses and maintaining body fluid and thermal homeostasis.
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111
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De Backer JF, Grunwald Kadow IC. A role for glia in cellular and systemic metabolism: insights from the fly. CURRENT OPINION IN INSECT SCIENCE 2022; 53:100947. [PMID: 35772690 DOI: 10.1016/j.cois.2022.100947] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Revised: 06/18/2022] [Accepted: 06/20/2022] [Indexed: 06/15/2023]
Abstract
Excitability and synaptic transmission make neurons high-energy consumers. However, neurons do not store carbohydrates or lipids. Instead, they need support cells to fuel their metabolic demands. This role is assumed by glia, both in vertebrates and invertebrates. Many questions remain regarding the coupling between neuronal activity and energy demand on the one hand, and nutrient supply by glia on the other hand. Here, we review recent advances showing that fly glia, similar to their role in vertebrates, fuel neurons in times of high energetic demand, such as during memory formation and long-term storage. Vertebrate glia also play a role in the modulation of neurons, their communication, and behavior, including food search and feeding. We discuss recent literature pointing to similar roles of fly glia in behavior and metabolism.
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Affiliation(s)
- Jean-François De Backer
- Technical University of Munich, School of Life Sciences, Liesel-Beckmann-Str. 4, 85354 Freising, Germany; University of Bonn, Faculty of Medicine, UKB, Institute of Physiology II, Nussallee 11, 53115 Bonn, Germany
| | - Ilona C Grunwald Kadow
- Technical University of Munich, School of Life Sciences, Liesel-Beckmann-Str. 4, 85354 Freising, Germany; University of Bonn, Faculty of Medicine, UKB, Institute of Physiology II, Nussallee 11, 53115 Bonn, Germany.
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112
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Increased Extrasynaptic Glutamate Escape in Stochastically Shaped Probabilistic Synaptic Environment. Biomedicines 2022; 10:biomedicines10102406. [PMID: 36289667 PMCID: PMC9599130 DOI: 10.3390/biomedicines10102406] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2022] [Revised: 09/18/2022] [Accepted: 09/19/2022] [Indexed: 12/30/2022] Open
Abstract
Excitatory synapses in the brain are often surrounded by nanoscopic astroglial processes that express high-affinity glutamate transporters at a high surface density. This ensures that the bulk of glutamate leaving the synaptic cleft is taken up for its subsequent metabolic conversion and replenishment in neurons. Furthermore, variations in the astroglial coverage of synapses can thus determine to what extent glutamate released into the synaptic cleft could activate its receptors outside the cleft. The biophysical determinants of extrasynaptic glutamate actions are complex because they involve a competition between transporters and target receptors of glutamate in the tortuous space of synaptic environment. To understand key spatiotemporal relationships between the extrasynaptic landscapes of bound and free glutamate, we explored a detailed Monte Carlo model for its release, diffusion, and uptake. We implemented a novel representation of brain neuropil in silico as a space filled with randomly scattered, overlapping spheres (spheroids) of distributed size. The parameters of perisynaptic space, astroglial presence, and glutamate transport were constrained by the empirical data obtained for the 'average' environment of common cortical synapses. Our simulations provide a glimpse of the perisynaptic concentration landscapes of free and transporter-bound glutamate relationship, suggesting a significant tail of space-average free glutamate within 3 ms post-release.
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113
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Higinio-Rodríguez F, Rivera-Villaseñor A, Calero-Vargas I, López-Hidalgo M. From nociception to pain perception, possible implications of astrocytes. Front Cell Neurosci 2022; 16:972827. [PMID: 36159392 PMCID: PMC9492445 DOI: 10.3389/fncel.2022.972827] [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: 06/19/2022] [Accepted: 08/15/2022] [Indexed: 11/15/2022] Open
Abstract
Astrocytes are determinants for the functioning of the CNS. They respond to neuronal activity with calcium increases and can in turn modulate synaptic transmission, brain plasticity as well as cognitive processes. Astrocytes display sensory-evoked calcium responses in different brain structures related to the discriminative system of most sensory modalities. In particular, noxious stimulation evoked calcium responses in astrocytes in the spinal cord, the hippocampus, and the somatosensory cortex. However, it is not clear if astrocytes are involved in pain. Pain is a private, personal, and complex experience that warns us about potential tissue damage. It is a perception that is not linearly associated with the amount of tissue damage or nociception; instead, it is constructed with sensory, cognitive, and affective components and depends on our previous experiences. However, it is not fully understood how pain is created from nociception. In this perspective article, we provide an overview of the mechanisms and neuronal networks that underlie the perception of pain. Then we proposed that coherent activity of astrocytes in the spinal cord and pain-related brain areas could be important in binding sensory, affective, and cognitive information on a slower time scale.
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Affiliation(s)
- Frida Higinio-Rodríguez
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Querétaro, Mexico
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Mexico
| | - Angélica Rivera-Villaseñor
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Querétaro, Mexico
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Mexico
| | - Isnarhazni Calero-Vargas
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Querétaro, Mexico
- Instituto de Neurobiología, Universidad Nacional Autónoma de México, Querétaro, Mexico
| | - Mónica López-Hidalgo
- Escuela Nacional de Estudios Superiores, Universidad Nacional Autónoma de México, Querétaro, Mexico
- *Correspondence: Mónica López-Hidalgo,
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Harnessing conserved signaling and metabolic pathways to enhance the maturation of functional engineered tissues. NPJ Regen Med 2022; 7:44. [PMID: 36057642 PMCID: PMC9440900 DOI: 10.1038/s41536-022-00246-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 08/05/2022] [Indexed: 11/08/2022] Open
Abstract
The development of induced-pluripotent stem cell (iPSC)-derived cell types offers promise for basic science, drug testing, disease modeling, personalized medicine, and translatable cell therapies across many tissue types. However, in practice many iPSC-derived cells have presented as immature in physiological function, and despite efforts to recapitulate adult maturity, most have yet to meet the necessary benchmarks for the intended tissues. Here, we summarize the available state of knowledge surrounding the physiological mechanisms underlying cell maturation in several key tissues. Common signaling consolidators, as well as potential synergies between critical signaling pathways are explored. Finally, current practices in physiologically relevant tissue engineering and experimental design are critically examined, with the goal of integrating greater decision paradigms and frameworks towards achieving efficient maturation strategies, which in turn may produce higher-valued iPSC-derived tissues.
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Li RF, Gui F, Yu C, Luo YM, Guo L. Protective role of muscones on astrocytes under a mechanical-chemical damage model. ANNALS OF TRANSLATIONAL MEDICINE 2022; 10:927. [PMID: 36172099 PMCID: PMC9511184 DOI: 10.21037/atm-22-3848] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 09/06/2022] [Indexed: 11/21/2022]
Abstract
Background Traumatic spinal cord injury (SCI) is a major clinical concern and a life-changing neurological condition with substantial socioeconomic implications. The initial mechanical force applied to the spinal cord at the time of injury is known as the primary injury. After the primary injury, ischemia and hypoxia induce cell death and autolysis, which are associated with the release of a group of inflammatory factors and biologically active substances, such as superoxide dismutase (SOD), malonaldehyde (MDA), lactate dehydrogenase (LDH), and tumor necrosis factor-α (TNF-α). These processes are called the secondary injury, and may lead to an excess of extracellular glutamate (Glu), which in turn promotes the neuronal injuries. Muscone has been shown to have anti-inflammatory effects in the treatment of brain diseases and other diseases. However, to date, no study has examined the effects of muscone in the treatment of SCI. Methods Astrocytes were separated and purified by the method of short-term exposure combining with differential sticking wall. Astrocyte was identified by glial fibers acidic protein (GFAP) selecting cell immunochemical staining. A mechanical-chemical damage (MCD) model was established via the primary spinal astrocytes of rats, and treatment was administered with different concentrations of muscone. 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay (MTT) was detected at 6, 12, 24, 48 and 72 h. SOD, MDA, LDH, TNF-alpha and intracellular calcium was detected at 3, 6 and 12 h. Glu in supernatant was detected respectively at 3, 6 and 12 h by enzyme-linked immunosorbent assay (ELISA) method. Intracellular calcium was detected respectively at 3, 6 and 12 h by flow cytometry method. MRNA expression of excitatory amino acid transporters (EAATs) and GFAP were detected by the quantitative reverse transcription polymerase chain reaction (qRT-PCR) method and protein expression of those by western blot at 6 h. Results Muscone reduced the levels of LDH, TNF-α, and MDA after injury, and upregulated the level of SOD. Muscone also reduced the density of extracellular Glu and suppressed the intracellular calcium level. Additionally, it decreased the expression levels of EAATs and GFAPs. Conclusions Muscone has a protective effect on astrocytes in a MCD and inhibits astrocytes’ proliferation.
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Affiliation(s)
- Rui-Fu Li
- Department of Orthopedics, University-Town Hospital of Chongqing Medical University, Chongqing, China
| | - Fei Gui
- Department of Orthopedics, University-Town Hospital of Chongqing Medical University, Chongqing, China
| | - Chao Yu
- Department of Orthopedics, University-Town Hospital of Chongqing Medical University, Chongqing, China
| | - Yuan-Meng Luo
- Department of Orthopedics, University-Town Hospital of Chongqing Medical University, Chongqing, China
| | - Liang Guo
- Department of Orthopedics, University-Town Hospital of Chongqing Medical University, Chongqing, China
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Abstract
Astrocytic calcium dynamics has been implicated in the encoding of sensory information1-5, and modulation of calcium in astrocytes has been shown to affect behaviour6-10. However, longitudinal investigation of the real-time calcium activity of astrocytes in the hippocampus of awake mice is lacking. Here we used two-photon microscopy to chronically image CA1 astrocytes as mice ran in familiar or new virtual environments to obtain water rewards. We found that astrocytes exhibit persistent ramping activity towards the reward location in a familiar environment, but not in a new one. Shifting the reward location within a familiar environment also resulted in diminished ramping. After additional training, as the mice became familiar with the new context or new reward location, the ramping was re-established. Using linear decoders, we could predict the location of the mouse in a familiar environment from astrocyte activity alone. We could not do the same in a new environment, suggesting that the spatial modulation of astrocytic activity is experience dependent. Our results indicate that astrocytes can encode the expected reward location in spatial contexts, thereby extending their known computational abilities and their role in cognitive functions.
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Glutamate Signaling and Filopodiagenesis of Astrocytoma Cells in Brain Cancers: Survey and Questions. Cells 2022; 11:cells11172657. [PMID: 36078065 PMCID: PMC9454653 DOI: 10.3390/cells11172657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 08/19/2022] [Accepted: 08/24/2022] [Indexed: 11/22/2022] Open
Abstract
Astrocytes are non-excitable cells in the CNS that can cause life-threatening astrocytoma tumors when they transform to cancerous cells. Perturbed homeostasis of the neurotransmitter glutamate is associated with astrocytoma tumor onset and progression, but the factors that govern this phenomenon are less known. Herein, we review possible mechanisms by which glutamate may act in facilitating the growth of projections in astrocytic cells. This review discusses the similarities and differences between the morphology of astrocytes and astrocytoma cells, and the role that dysregulation in glutamate and calcium signaling plays in the aberrant morphology of astrocytoma cells. Converging reports suggest that ionotropic glutamate receptors and voltage-gated calcium channels expressed in astrocytes may be responsible for the abnormal filopodiagenesis or process extension leading to astrocytoma cells’ infiltration throughout the brain.
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Butcher JB, Sims RE, Ngum NM, Bazzari AH, Jenkins SI, King M, Hill EJ, Nagel DA, Fox K, Parri HR, Glazewski S. A requirement for astrocyte IP3R2 signaling for whisker experience-dependent depression and homeostatic upregulation in the mouse barrel cortex. Front Cell Neurosci 2022; 16:905285. [PMID: 36090792 PMCID: PMC9452848 DOI: 10.3389/fncel.2022.905285] [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: 03/26/2022] [Accepted: 07/06/2022] [Indexed: 11/19/2022] Open
Abstract
Changes to sensory experience result in plasticity of synapses in the cortex. This experience-dependent plasticity (EDP) is a fundamental property of the brain. Yet, while much is known about neuronal roles in EDP, very little is known about the role of astrocytes. To address this issue, we used the well-described mouse whiskers-to-barrel cortex system, which expresses a number of forms of EDP. We found that all-whisker deprivation induced characteristic experience-dependent Hebbian depression (EDHD) followed by homeostatic upregulation in L2/3 barrel cortex of wild type mice. However, these changes were not seen in mutant animals (IP3R2–/–) that lack the astrocyte-expressed IP3 receptor subtype. A separate paradigm, the single-whisker experience, induced potentiation of whisker-induced response in both wild-type (WT) mice and IP3R2–/– mice. Recordings in ex vivo barrel cortex slices reflected the in vivo results so that long-term depression (LTD) could not be elicited in slices from IP3R2–/– mice, but long-term potentiation (LTP) could. Interestingly, 1 Hz stimulation inducing LTD in WT paradoxically resulted in NMDAR-dependent LTP in slices from IP3R2–/– animals. The LTD to LTP switch was mimicked by acute buffering astrocytic [Ca2+]i in WT slices. Both WT LTD and IP3R2–/– 1 Hz LTP were mediated by non-ionotropic NMDAR signaling, but only WT LTD was P38 MAPK dependent, indicating an underlying mechanistic switch. These results demonstrate a critical role for astrocytic [Ca2+]i in several EDP mechanisms in neocortex.
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Affiliation(s)
- John B. Butcher
- School of Life Sciences, Keele University, Keele, United Kingdom
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - Robert E. Sims
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - Neville M. Ngum
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - Amjad H. Bazzari
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - Stuart I. Jenkins
- Neural Tissue Engineering Group, Institute for Science and Technology in Medicine (ISTM), Keele University, Keele, United Kingdom
| | - Marianne King
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - Eric J. Hill
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
| | - David A. Nagel
- Aston Medical School, Aston Medical Research Institute, Aston University, Birmingham, United Kingdom
| | - Kevin Fox
- School of Biosciences, Cardiff University, Cardiff, United Kingdom
| | - H. Rheinallt Parri
- College of Health and Life Sciences, Aston University, Birmingham, United Kingdom
- *Correspondence: H. Rheinallt Parri,
| | - Stanislaw Glazewski
- School of Life Sciences, Keele University, Keele, United Kingdom
- Stanislaw Glazewski,
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Lee WS, Kang JH, Lee JH, Kim YS, Kim JJ, Kim HS, Kim HW, Shin US, Yoon BE. Improved gliotransmission by increasing intracellular Ca 2+ via TRPV1 on multi-walled carbon nanotube platforms. J Nanobiotechnology 2022; 20:367. [PMID: 35953847 PMCID: PMC9367080 DOI: 10.1186/s12951-022-01551-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2022] [Accepted: 07/08/2022] [Indexed: 11/13/2022] Open
Abstract
Background Astrocyte is a key regulator of neuronal activity and excitatory/inhibitory balance via gliotransmission. Recently, gliotransmission has been identified as a novel target for neurological diseases. However, using the properties of nanomaterials to modulate gliotransmission has not been uncovered. Results We prepared non-invasive CNT platforms for cells with different nanotopography and properties such as hydrophilicity and conductivity. Using CNT platforms, we investigated the effect of CNT on astrocyte functions participating in synaptic transmission by releasing gliotransmitters. Astrocytes on CNT platforms showed improved cell adhesion and proliferation with upregulated integrin and GFAP expression. In addition, intracellular GABA and glutamate in astrocytes were augmented on CNT platforms. We also demonstrated that gliotransmitters in brain slices were increased by ex vivo incubation with CNT. Additionally, intracellular resting Ca2+ level, which is important for gliotransmission, was also increased via TRPV1 on CNT platforms. Conclusion CNT can improve astrocyte function including adhesion, proliferation and gliotransmission by increasing resting Ca2+ level. Therefore, our study suggests that CNT would be utilized as a new therapeutic platform for central nervous system diseases by modulating gliotransmission. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12951-022-01551-1.
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Affiliation(s)
- Won-Seok Lee
- Department of Molecular Biology, Dankook University, Cheonan, 31116, Republic of Korea.,Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, 31116, Republic of Korea.,Mechanobiology Dental Medicine Research Center, Cheonan, 31116, Republic of Korea
| | - Ji-Hye Kang
- Department of Nanobiomedical Science, BK21 FOUR NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan, 31116, Republic of Korea.,Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, 31116, Republic of Korea
| | - Jung-Hwan Lee
- Department of Nanobiomedical Science, BK21 FOUR NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan, 31116, Republic of Korea.,Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, 31116, Republic of Korea.,Department of Biomaterials Science, College of Dentistry, Dankook University, Cheonan, 31116, Republic of Korea.,Dental Medicine Innovation Centre, UCL Eastman-Korea, Dankook University, Cheonan, 31116, Republic of Korea.,Mechanobiology Dental Medicine Research Center, Cheonan, 31116, Republic of Korea
| | - Yoo Sung Kim
- Department of Molecular Biology, Dankook University, Cheonan, 31116, Republic of Korea
| | - Jongmin Joseph Kim
- Department of Molecular Biology, Dankook University, Cheonan, 31116, Republic of Korea
| | - Han-Sem Kim
- Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, 31116, Republic of Korea
| | - Hae-Won Kim
- Department of Nanobiomedical Science, BK21 FOUR NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan, 31116, Republic of Korea.,Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, 31116, Republic of Korea.,Department of Biomaterials Science, College of Dentistry, Dankook University, Cheonan, 31116, Republic of Korea.,Dental Medicine Innovation Centre, UCL Eastman-Korea, Dankook University, Cheonan, 31116, Republic of Korea.,Mechanobiology Dental Medicine Research Center, Cheonan, 31116, Republic of Korea
| | - Ueon Sang Shin
- Department of Nanobiomedical Science, BK21 FOUR NBM Global Research Center for Regenerative Medicine, Dankook University, Cheonan, 31116, Republic of Korea. .,Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, 31116, Republic of Korea.
| | - Bo-Eun Yoon
- Department of Molecular Biology, Dankook University, Cheonan, 31116, Republic of Korea. .,Institute of Tissue Regeneration Engineering (ITREN), Dankook University, Cheonan, 31116, Republic of Korea. .,Mechanobiology Dental Medicine Research Center, Cheonan, 31116, Republic of Korea.
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Astrocytic Piezo1-mediated mechanotransduction determines adult neurogenesis and cognitive functions. Neuron 2022; 110:2984-2999.e8. [PMID: 35963237 DOI: 10.1016/j.neuron.2022.07.010] [Citation(s) in RCA: 42] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 05/31/2022] [Accepted: 07/12/2022] [Indexed: 12/12/2022]
Abstract
Adult brain activities are generally believed to be dominated by chemical and electrical transduction mechanisms. However, the importance of mechanotransduction mediated by mechano-gated ion channels in brain functions is less appreciated. Here, we show that the mechano-gated Piezo1 channel is expressed in the exploratory processes of astrocytes and utilizes its mechanosensitivity to mediate mechanically evoked Ca2+ responses and ATP release, establishing Piezo1-mediated mechano-chemo transduction in astrocytes. Piezo1 deletion in astrocytes causes a striking reduction of hippocampal volume and brain weight and severely impaired (but ATP-rescuable) adult neurogenesis in vivo, and it abolishes ATP-dependent potentiation of neural stem cell (NSC) proliferation in vitro. Piezo1-deficient mice show impaired hippocampal long-term potentiation (LTP) and learning and memory behaviors. By contrast, overexpression of Piezo1 in astrocytes sufficiently enhances mechanotransduction, LTP, and learning and memory performance. Thus, astrocytes utilize Piezo1-mediated mechanotransduction mechanisms to robustly regulate adult neurogenesis and cognitive functions, conceptually highlighting the importance of mechanotransduction in brain structure and function.
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Looking to the stars for answers: Strategies for determining how astrocytes influence neuronal activity. Comput Struct Biotechnol J 2022; 20:4146-4156. [PMID: 36016711 PMCID: PMC9379862 DOI: 10.1016/j.csbj.2022.07.052] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 07/29/2022] [Accepted: 07/29/2022] [Indexed: 11/24/2022] Open
Abstract
Astrocytes are critical components of neural circuits positioned in close proximity to the synapse, allowing them to rapidly sense and respond to neuronal activity. One repeatedly observed biomarker of astroglial activation is an increase in intracellular Ca2+ levels. These astroglial Ca2+ signals are often observed spreading throughout various cellular compartments from perisynaptic astroglial processes, to major astrocytic branches and on to the soma or cell body. Here we review recent evidence demonstrating that astrocytic Ca2+ events are remarkably heterogeneous in both form and function, propagate through the astroglial syncytia, and are directly linked to the ability of astroglia to influence local neuronal activity. As many of the cellular functions of astroglia can be linked to intracellular Ca2+ signaling, and the diversity and heterogeneity of these events becomes more apparent, there is an increasing need for novel experimental strategies designed to better understand the how these signals evolve in parallel with neuronal activity. Here we review the recent advances that enable the characterization of both subcellular and population-wide astrocytic Ca2+ dynamics. Additionally, we also outline the experimental design required for simultaneous in vivo Ca2+ imaging in the context of neuronal or astroglial manipulation, highlighting new experimental strategies made possible by recent advances in viral vector, imaging, and quantification technologies. Through combined usage of these reagents and methodologies, we provide a conceptual framework to study how astrocytes functionally integrate into neural circuits and to what extent they influence and direct the synaptic activity underlying behavioral responses.
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Glucocorticoid Receptor-Dependent Astrocytes Mediate Stress Vulnerability. Biol Psychiatry 2022; 92:204-215. [PMID: 35151464 DOI: 10.1016/j.biopsych.2021.11.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 11/04/2021] [Accepted: 11/28/2021] [Indexed: 12/24/2022]
Abstract
BACKGROUND Major depressive disorder is a devastating psychiatric illness that affects approximately 17% of the population worldwide. Astrocyte dysfunction has been implicated in its pathophysiology. Traumatic experiences and stress contribute to the onset of major depressive disorder, but how astrocytes respond to stress is poorly understood. METHODS Using Western blotting analysis, we identified that stress vulnerability was associated with reduced astrocytic glucocorticoid receptor (GR) expression in mouse models of depression. We further investigated the functions of astrocytic GRs in regulating depression and the underlying mechanisms by using a combination of behavioral studies, fiber photometry, biochemical experiments, and RNA sequencing methods. RESULTS GRs in astrocytes were more sensitive to stress than those in neurons. GR absence in astrocytes induced depressive-like behaviors, whereas restoring astrocytic GR expression in the medial prefrontal cortex prevented the depressive-like phenotype. Furthermore, we found that GRs in the medial prefrontal cortex affected astrocytic Ca2+ activity and dynamic ATP (adenosine 5'-triphosphate) release in response to stress. RNA sequencing of astrocytes isolated from GR deletion mice identified the PI3K-Akt (phosphoinositide 3-kinase-Akt) signaling pathway, which was required for astrocytic GR-mediated ATP release. CONCLUSIONS These findings reveal that astrocytic GRs play an important role in stress response and that reduced astrocytic GR expression in the stressed subject decreases ATP release to mediate stress vulnerability.
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123
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Gourine AV, Dale N. Brain H + /CO 2 sensing and control by glial cells. Glia 2022; 70:1520-1535. [PMID: 35102601 DOI: 10.1002/glia.24152] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 01/11/2022] [Accepted: 01/17/2022] [Indexed: 01/04/2023]
Abstract
Maintenance of constant brain pH is critically important to support the activity of individual neurons, effective communication within the neuronal circuits, and, thus, efficient processing of information by the brain. This review article focuses on how glial cells detect and respond to changes in brain tissue pH and concentration of CO2 , and then trigger systemic and local adaptive mechanisms that ensure a stable milieu for the operation of brain circuits. We give a detailed account of the cellular and molecular mechanisms underlying sensitivity of glial cells to H+ and CO2 and discuss the role of glial chemosensitivity and signaling in operation of three key mechanisms that work in concert to keep the brain pH constant. We discuss evidence suggesting that astrocytes and marginal glial cells of the brainstem are critically important for central respiratory CO2 chemoreception-a fundamental physiological mechanism that regulates breathing in accord with changes in blood and brain pH and partial pressure of CO2 in order to maintain systemic pH homeostasis. We review evidence suggesting that astrocytes are also responsible for the maintenance of local brain tissue extracellular pH in conditions of variable acid loads associated with changes in the neuronal activity and metabolism, and discuss potential role of these glial cells in mediating the effects of CO2 on cerebral vasculature.
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Affiliation(s)
- Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
| | - Nicholas Dale
- School of Life Sciences, University of Warwick, Coventry, UK
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Pillai AG, Nadkarni S. Amyloid pathology disrupts gliotransmitter release in astrocytes. PLoS Comput Biol 2022; 18:e1010334. [PMID: 35913987 PMCID: PMC9371304 DOI: 10.1371/journal.pcbi.1010334] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Revised: 08/11/2022] [Accepted: 06/28/2022] [Indexed: 01/11/2023] Open
Abstract
Accumulation of amyloid-beta (Aβ) is associated with synaptic dysfunction and destabilization of astrocytic calcium homeostasis. A growing body of evidence support astrocytes as active modulators of synaptic transmission via calcium-mediated gliotransmission. However, the details of mechanisms linking Aβ signaling, astrocytic calcium dynamics, and gliotransmission are not known. We developed a biophysical model that describes calcium signaling and the ensuing gliotransmitter release from a single astrocytic process when stimulated by glutamate release from hippocampal neurons. The model accurately captures the temporal dynamics of microdomain calcium signaling and glutamate release via both kiss-and-run and full-fusion exocytosis. We investigate the roles of two crucial calcium regulating machineries affected by Aβ: plasma-membrane calcium pumps (PMCA) and metabotropic glutamate receptors (mGluRs). When we implemented these Aβ-affected molecular changes in our astrocyte model, it led to an increase in the rate and synchrony of calcium events. Our model also reproduces several previous findings of Aβ associated aberrant calcium activity, such as increased intracellular calcium level and increased spontaneous calcium activity, and synchronous calcium events. The study establishes a causal link between previous observations of hyperactive astrocytes in Alzheimer’s disease (AD) and Aβ-induced modifications in mGluR and PMCA functions. Analogous to neurotransmitter release, gliotransmitter exocytosis closely tracks calcium changes in astrocyte processes, thereby guaranteeing tight control of synaptic signaling by astrocytes. However, the downstream effects of AD-related calcium changes in astrocytes on gliotransmitter release are not known. Our results show that enhanced rate of exocytosis resulting from modified calcium signaling in astrocytes leads to a rapid depletion of docked vesicles that disrupts the crucial temporal correspondence between a calcium event and vesicular release. We propose that the loss of temporal correspondence between calcium events and gliotransmission in astrocytes pathologically alters astrocytic modulation of synaptic transmission in the presence of Aβ accumulation. Signaling by astrocytes is critical to information processing at synapses, and its aberration plays a central role in neurological diseases, especially Alzheimer’s disease (AD). A complete characterization of calcium signaling and the resulting pattern of gliotransmitter release from fine astrocytic processes are not accessible to current experimental tools. We developed a biophysical model that can quantitatively describe signaling by astrocytes in response to a wide range of synaptic activity. We show that AD-related molecular alterations disrupt the concurrence of calcium and gliotransmitter release events, a characterizing feature that enables astrocytes to influence synaptic signaling.
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Affiliation(s)
| | - Suhita Nadkarni
- Indian Institute of Science Education and Research Pune, Pune, India
- * E-mail:
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Dias L, Madeira D, Dias R, Tomé ÂR, Cunha RA, Agostinho P. Aβ 1-42 peptides blunt the adenosine A 2A receptor-mediated control of the interplay between P 2X 7 and P 2Y 1 receptors mediated calcium responses in astrocytes. Cell Mol Life Sci 2022; 79:457. [PMID: 35907034 PMCID: PMC11071907 DOI: 10.1007/s00018-022-04492-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 06/22/2022] [Accepted: 07/15/2022] [Indexed: 12/21/2022]
Abstract
The contribution of astrocytes to Alzheimer's disease (AD) is still ill defined. AD involves an abnormal accumulation of amyloid-β peptides (Aβ) and increased production of danger signals such as ATP. ATP can direct or indirectly, through its metabolism into adenosine, trigger adaptive astrocytic responses resulting from intracellular Ca2+ oscillations. AD also triggers an upregulation of astrocytic adenosine A2A receptors (A2AR), which blockade prevents memory dysfunction in AD. We now investigated how Aβ peptides affect ATP-mediated Ca2+ responses in astrocytes measured by fluorescence live-cell imaging and whether A2AR control astrocytic Ca2+ responses mediated by ATP receptors, mainly P2X7R and P2Y1R. In primary cultures of rat astrocytes exposed to Aβ1-42, ATP-evoked Ca2+ responses had a lower amplitude but a longer duration than in control astrocytes and involved P2X7R and P2Y1R, the former potentiating the later. Moreover, Aβ1-42 exposure increased protein levels of P2Y1R in astrocytes. A2AR antagonism with SCH58261 controlled in a protein kinase A-dependent manner both P2X7R- and P2Y1R-mediated Ca2+ responses in astrocytes. The interplay between these purinoceptors in astrocytes was blunted upon exposure to Aβ1-42. These findings uncover the ability of A2AR to regulate the inter-twinned P2X7R- and P2Y1R-mediated Ca2+ dynamics in astrocytes, which is disrupted in conditions of early AD.
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Affiliation(s)
- Liliana Dias
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Rua Larga, Polo I FMUC, 1st Floor, 3004-504, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Rua Larga, Polo I FMUC, 1st Floor, 3004-504, Coimbra, Portugal
| | - Daniela Madeira
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Rua Larga, Polo I FMUC, 1st Floor, 3004-504, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Rua Larga, Polo I FMUC, 1st Floor, 3004-504, Coimbra, Portugal
| | - Rafael Dias
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Rua Larga, Polo I FMUC, 1st Floor, 3004-504, Coimbra, Portugal
| | - Ângelo R Tomé
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Rua Larga, Polo I FMUC, 1st Floor, 3004-504, Coimbra, Portugal
- Department of Life Sciences, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal
| | - Rodrigo A Cunha
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Rua Larga, Polo I FMUC, 1st Floor, 3004-504, Coimbra, Portugal
- Faculty of Medicine, University of Coimbra, Rua Larga, Polo I FMUC, 1st Floor, 3004-504, Coimbra, Portugal
| | - Paula Agostinho
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Rua Larga, Polo I FMUC, 1st Floor, 3004-504, Coimbra, Portugal.
- Faculty of Medicine, University of Coimbra, Rua Larga, Polo I FMUC, 1st Floor, 3004-504, Coimbra, Portugal.
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Guan A, Wang S, Huang A, Qiu C, Li Y, Li X, Wang J, Wang Q, Deng B. The role of gamma oscillations in central nervous system diseases: Mechanism and treatment. Front Cell Neurosci 2022; 16:962957. [PMID: 35966207 PMCID: PMC9374274 DOI: 10.3389/fncel.2022.962957] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 07/11/2022] [Indexed: 12/15/2022] Open
Abstract
Gamma oscillation is the synchronization with a frequency of 30–90 Hz of neural oscillations, which are rhythmic electric processes of neuron groups in the brain. The inhibitory interneuron network is necessary for the production of gamma oscillations, but certain disruptions such as brain inflammation, oxidative stress, and metabolic imbalances can cause this network to malfunction. Gamma oscillations specifically control the connectivity between different brain regions, which is crucial for perception, movement, memory, and emotion. Studies have linked abnormal gamma oscillations to conditions of the central nervous system, including Alzheimer’s disease, Parkinson’s disease, and schizophrenia. Evidence suggests that gamma entrainment using sensory stimuli (GENUS) provides significant neuroprotection. This review discusses the function of gamma oscillations in advanced brain activities from both a physiological and pathological standpoint, and it emphasizes gamma entrainment as a potential therapeutic approach for a range of neuropsychiatric diseases.
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Affiliation(s)
- Ao Guan
- Department of Anesthesiology, Center for Brain Science, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- School of Medicine, Xiamen University, Xiamen, China
| | - Shaoshuang Wang
- Department of Anesthesiology, Center for Brain Science, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Ailing Huang
- Department of Anesthesiology, School of Medicine, Xiang’an Hospital of Xiamen University, Xiamen University, Xiamen, China
| | - Chenyue Qiu
- Department of Anesthesiology, School of Medicine, Xiang’an Hospital of Xiamen University, Xiamen University, Xiamen, China
| | - Yansong Li
- Department of Anesthesiology, Center for Brain Science, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Xuying Li
- Department of Anesthesiology, Center for Brain Science, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Department of Anesthesiology, School of Medicine, Xiang’an Hospital of Xiamen University, Xiamen University, Xiamen, China
| | - Jinfei Wang
- School of Medicine, Xiamen University, Xiamen, China
| | - Qiang Wang
- Department of Anesthesiology, Center for Brain Science, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Qiang Wang,
| | - Bin Deng
- Department of Anesthesiology, Center for Brain Science, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Department of Anesthesiology, School of Medicine, Xiang’an Hospital of Xiamen University, Xiamen University, Xiamen, China
- *Correspondence: Bin Deng,
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127
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Baudon A, Clauss Creusot E, Althammer F, Schaaf CP, Charlet A. Emerging role of astrocytes in oxytocin-mediated control of neural circuits and brain functions. Prog Neurobiol 2022; 217:102328. [PMID: 35870680 DOI: 10.1016/j.pneurobio.2022.102328] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 07/01/2022] [Accepted: 07/18/2022] [Indexed: 11/19/2022]
Abstract
The neuropeptide oxytocin has been in the focus of scientists for decades due to its profound and pleiotropic effects on physiology, activity of neuronal circuits and behaviors, among which sociality. Until recently, it was believed that oxytocinergic action exclusively occurs through direct activation of neuronal oxytocin receptors. However, several studies demonstrated the existence and functional relevance of astroglial oxytocin receptors in various brain regions in the mouse and rat brain. Astrocytic signaling and activity is critical for many important physiological processes including metabolism, neurotransmitter clearance from the synaptic cleft and integrated brain functions. While it can be speculated that oxytocinergic action on astrocytes predominantly facilitates neuromodulation via the release of specific gliotransmitters, the precise role of astrocytic oxytocin receptors remains elusive. In this review, we discuss the latest studies on the interaction between the oxytocinergic system and astrocytes, including detailed information about intracellular cascades, and speculate about future research directions on astrocytic oxytocin signaling.
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Affiliation(s)
- Angel Baudon
- Centre National de la Recherche Scientifique and University of Strasbourg, Institute of Cellular and Integrative Neuroscience, Strasbourg 67000 France
| | - Etienne Clauss Creusot
- Centre National de la Recherche Scientifique and University of Strasbourg, Institute of Cellular and Integrative Neuroscience, Strasbourg 67000 France
| | | | | | - Alexandre Charlet
- Centre National de la Recherche Scientifique and University of Strasbourg, Institute of Cellular and Integrative Neuroscience, Strasbourg 67000 France.
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128
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Shen W, Li Z, Tang Y, Han P, Zhu F, Dong J, Ma T, Zhao K, Zhang X, Xie Y, Zeng LH. Somatostatin interneurons inhibit excitatory transmission mediated by astrocytic GABA B and presynaptic GABA B and adenosine A 1 receptors in the hippocampus. J Neurochem 2022; 163:310-326. [PMID: 35775994 DOI: 10.1111/jnc.15662] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2021] [Revised: 06/14/2022] [Accepted: 06/21/2022] [Indexed: 11/29/2022]
Abstract
GABAergic network activity has been established to be involved in numerous physiological processes and pathological conditions. Extensive studies have corroborated that GABAergic network activity regulates excitatory synaptic networks by activating presynaptic GABAB receptors (GABAB Rs). It is well documented that astrocytes express GABAB Rs and respond to GABAergic network activity. However, little is known about whether astrocytic GABAB Rs regulate excitatory synaptic transmission mediated by GABAergic network activity. To address this issue, we combined whole-cell recordings, optogenetics, calcium imaging, and pharmacological approaches to specifically activate hippocampal somatostatin-expressing interneurons (SOM-INs), a type of interneuron that targets pyramidal cell dendrites, while monitoring excitatory synaptic transmission in CA1 pyramidal cells. We found that optogenetic stimulation of SOM-INs increases astrocyte Ca2+ signaling via the activation of astrocytic GABAB Rs and GAT-3. SOM-INs depress excitatory neurotransmission by activating presynaptic GABAB Rs and astrocytic GABAB Rs, the latter inducing the release of ATP/adenosine. In turn, adenosine inhibits excitatory synaptic transmission by activating presynaptic adenosine A1 receptors (A1 Rs). Overall, our results reveal a novel mechanism that SOM-INs activation-induced synaptic depression is partially mediated by the activation of astrocytic GABAB Rs.
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Affiliation(s)
- Weida Shen
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Zijing Li
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Yejiao Tang
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Pufan Han
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Feng Zhu
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Jingyin Dong
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Tianyu Ma
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Kai Zhao
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Xin Zhang
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
| | - Yicheng Xie
- The Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center for Child Health, Hangzhou, China
| | - Ling-Hui Zeng
- School of Medicine, Zhejiang University City College, Hangzhou, Zhejiang, China
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129
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Burboa PC, Puebla M, Gaete PS, Durán WN, Lillo MA. Connexin and Pannexin Large-Pore Channels in Microcirculation and Neurovascular Coupling Function. Int J Mol Sci 2022; 23:ijms23137303. [PMID: 35806312 PMCID: PMC9266979 DOI: 10.3390/ijms23137303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 01/27/2023] Open
Abstract
Microcirculation homeostasis depends on several channels permeable to ions and/or small molecules that facilitate the regulation of the vasomotor tone, hyperpermeability, the blood–brain barrier, and the neurovascular coupling function. Connexin (Cxs) and Pannexin (Panxs) large-pore channel proteins are implicated in several aspects of vascular physiology. The permeation of ions (i.e., Ca2+) and key metabolites (ATP, prostaglandins, D-serine, etc.) through Cxs (i.e., gap junction channels or hemichannels) and Panxs proteins plays a vital role in intercellular communication and maintaining vascular homeostasis. Therefore, dysregulation or genetic pathologies associated with these channels promote deleterious tissue consequences. This review provides an overview of current knowledge concerning the physiological role of these large-pore molecule channels in microcirculation (arterioles, capillaries, venules) and in the neurovascular coupling function.
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Affiliation(s)
- Pía C. Burboa
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, 185 South Orange Avenue, Newark, NJ 07103, USA; (P.C.B.); (W.N.D.)
- Departamento de Morfología y Función, Facultad de Salud y Ciencias Sociales, Sede Santiago Centro, Universidad de las Américas, Avenue República 71, Santiago 8370040, Chile;
| | - Mariela Puebla
- Departamento de Morfología y Función, Facultad de Salud y Ciencias Sociales, Sede Santiago Centro, Universidad de las Américas, Avenue República 71, Santiago 8370040, Chile;
| | - Pablo S. Gaete
- Department of Physiology and Membrane Biology, University of California at Davis, Davis, CA 95616, USA;
| | - Walter N. Durán
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, 185 South Orange Avenue, Newark, NJ 07103, USA; (P.C.B.); (W.N.D.)
- Rutgers School of Graduate Studies, 185 South Orange Avenue, Newark, NJ 07103, USA
| | - Mauricio A. Lillo
- Department of Pharmacology, Physiology and Neuroscience, New Jersey Medical School, Rutgers University, 185 South Orange Avenue, Newark, NJ 07103, USA; (P.C.B.); (W.N.D.)
- Correspondence:
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130
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Hulshof LA, van Nuijs D, Hol EM, Middeldorp J. The Role of Astrocytes in Synapse Loss in Alzheimer's Disease: A Systematic Review. Front Cell Neurosci 2022; 16:899251. [PMID: 35783099 PMCID: PMC9244621 DOI: 10.3389/fncel.2022.899251] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Accepted: 05/23/2022] [Indexed: 11/25/2022] Open
Abstract
Alzheimer's disease (AD) is the most common cause of dementia, affecting 35 million people worldwide. One pathological feature of progressing AD is the loss of synapses. This is the strongest correlate of cognitive decline. Astrocytes, as an essential part of the tripartite synapse, play a role in synapse formation, maintenance, and elimination. During AD, astrocytes get a reactive phenotype with an altered gene expression profile and changed function compared to healthy astrocytes. This process likely affects their interaction with synapses. This systematic review aims to provide an overview of the scientific literature including information on how astrocytes affect synapse formation and elimination in the brain of AD patients and in animal models of the disease. We review molecular and cellular changes in AD astrocytes and conclude that these predominantly result in lower synapse numbers, indicative of decreased synapse support or even synaptotoxicity, or increased elimination, resulting in synapse loss, and consequential cognitive decline, as associated with AD. Preventing AD induced changes in astrocytes might therefore be a potential therapeutic target for dementia. Systematic Review Registration:https://www.crd.york.ac.uk/prospero/display_record.php?RecordID=148278, identifier [CRD148278].
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Affiliation(s)
- Lianne A. Hulshof
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, Netherlands
| | - Danny van Nuijs
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, Netherlands
| | - Elly M. Hol
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, Netherlands
| | - Jinte Middeldorp
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, Netherlands
- Department Neurobiology and Aging, Biomedical Primate Research Centre, Rijswijk, Netherlands
- *Correspondence: Jinte Middeldorp
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131
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Kim HB, Lu Y, Oh SC, Morris J, Miyashiro K, Kim J, Eberwine J, Sul JY. Astrocyte ethanol exposure reveals persistent and defined calcium response subtypes and associated gene signatures. J Biol Chem 2022; 298:102147. [PMID: 35716779 PMCID: PMC9293641 DOI: 10.1016/j.jbc.2022.102147] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2022] [Revised: 06/10/2022] [Accepted: 06/12/2022] [Indexed: 11/26/2022] Open
Abstract
Astrocytes play a critical role in brain function, but their contribution during ethanol (EtOH) consumption remains largely understudied. In light of recent findings on the heterogeneity of astrocyte physiology and gene expression, an approach with the ability to identify subtypes and capture this heterogeneity is necessary. Here, we combined measurements of calcium signaling and gene expression to define EtOH-induced astrocyte subtypes. In the absence of a demonstrated EtOH receptor, EtOH is believed to have effects on the function of many receptors and downstream biological cascades that underlie calcium responsiveness. This mechanism of EtOH-induced calcium signaling is unknown and this study provides the first step in understanding the characteristics of cells displaying these observed responses. To characterize underlying astrocyte subtypes, we assessed the correlation between calcium signaling and astrocyte gene expression signature in response to EtOH. We found that various EtOH doses increased intracellular calcium levels in a subset of astrocytes, distinguishing three cellular response types and one nonresponsive subtype as categorized by response waveform properties. Furthermore, single-cell RNA-seq analysis of astrocytes from the different response types identified type-enriched discriminatory gene expression signatures. Combining single-cell calcium responses and gene expression analysis identified specific astrocyte subgroups among astrocyte populations defined by their response to EtOH. This result provides a basis for identifying the relationship between astrocyte susceptibility to EtOH and corresponding measurable markers of calcium signaling and gene expression, which will be useful to investigate potential subgroup-specific influences of astrocytes on the physiology and pathology of EtOH exposure in the brain.
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Affiliation(s)
- Hyun-Bum Kim
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Youtao Lu
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Seonkyung C Oh
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jacqueline Morris
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Kevin Miyashiro
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Junhyong Kim
- Department of Biology, School of Arts and Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA; PENN Program in Single Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - James Eberwine
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; PENN Program in Single Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Jai-Yoon Sul
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA; PENN Program in Single Cell Biology, University of Pennsylvania, Philadelphia, Pennsylvania, USA.
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Kempmann A, Gensch T, Offenhäusser A, Tihaa I, Maybeck V, Balfanz S, Baumann A. The Functional Characterization of GCaMP3.0 Variants Specifically Targeted to Subcellular Domains. Int J Mol Sci 2022; 23:ijms23126593. [PMID: 35743038 PMCID: PMC9223625 DOI: 10.3390/ijms23126593] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2022] [Revised: 05/31/2022] [Accepted: 06/06/2022] [Indexed: 11/16/2022] Open
Abstract
Calcium (Ca2+) ions play a pivotal role in physiology and cellular signaling. The intracellular Ca2+ concentration ([Ca2+]i) is about three orders of magnitude lower than the extracellular concentration, resulting in a steep transmembrane concentration gradient. Thus, the spatial and the temporal dynamics of [Ca2+]i are ideally suited to modulate Ca2+-mediated cellular responses to external signals. A variety of highly sophisticated methods have been developed to gain insight into cellular Ca2+ dynamics. In addition to electrophysiological measurements and the application of synthetic dyes that change their fluorescent properties upon interaction with Ca2+, the introduction and the ongoing development of genetically encoded Ca2+ indicators (GECI) opened a new era to study Ca2+-driven processes in living cells and organisms. Here, we have focused on one well-established GECI, i.e., GCaMP3.0. We have systematically modified the protein with sequence motifs, allowing localization of the sensor in the nucleus, in the mitochondrial matrix, at the mitochondrial outer membrane, and at the plasma membrane. The individual variants and a cytosolic version of GCaMP3.0 were overexpressed and purified from E. coli cells to study their biophysical properties in solution. All versions were examined to monitor Ca2+ signaling in stably transfected cell lines and in primary cortical neurons transduced with recombinant Adeno-associated viruses (rAAV). In this comparative study, we provide evidence for a robust approach to reliably trace Ca2+ signals at the (sub)-cellular level with pronounced temporal resolution.
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Affiliation(s)
- Annika Kempmann
- Institute of Biological Information Processing, IBI-1, Research Center Jülich, 52428 Jülich, Germany; (A.K.); (T.G.); (S.B.)
| | - Thomas Gensch
- Institute of Biological Information Processing, IBI-1, Research Center Jülich, 52428 Jülich, Germany; (A.K.); (T.G.); (S.B.)
| | - Andreas Offenhäusser
- Institute of Biological Information Processing, IBI-3, Research Center Jülich, 52428 Jülich, Germany; (A.O.); (I.T.); (V.M.)
| | - Irina Tihaa
- Institute of Biological Information Processing, IBI-3, Research Center Jülich, 52428 Jülich, Germany; (A.O.); (I.T.); (V.M.)
| | - Vanessa Maybeck
- Institute of Biological Information Processing, IBI-3, Research Center Jülich, 52428 Jülich, Germany; (A.O.); (I.T.); (V.M.)
| | - Sabine Balfanz
- Institute of Biological Information Processing, IBI-1, Research Center Jülich, 52428 Jülich, Germany; (A.K.); (T.G.); (S.B.)
| | - Arnd Baumann
- Institute of Biological Information Processing, IBI-1, Research Center Jülich, 52428 Jülich, Germany; (A.K.); (T.G.); (S.B.)
- Correspondence: ; Tel.: +49-2461-614014
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133
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Cell-Derived Exosomes as Therapeutic Strategies and Exosome-Derived microRNAs as Biomarkers for Traumatic Brain Injury. J Clin Med 2022; 11:jcm11113223. [PMID: 35683610 PMCID: PMC9181755 DOI: 10.3390/jcm11113223] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/30/2022] [Accepted: 05/31/2022] [Indexed: 02/01/2023] Open
Abstract
Traumatic brain injury (TBI) is a complex, life-threatening condition that causes mortality and disability worldwide. No effective treatment has been clinically verified to date. Achieving effective drug delivery across the blood–brain barrier (BBB) presents a major challenge to therapeutic drug development for TBI. Furthermore, the field of TBI biomarkers is rapidly developing to cope with the many aspects of TBI pathology and enhance clinical management of TBI. Exosomes (Exos) are endogenous extracellular vesicles (EVs) containing various biological materials, including lipids, proteins, microRNAs, and other nucleic acids. Compelling evidence exists that Exos, such as stem cell-derived Exos and even neuron or glial cell-derived Exos, are promising TBI treatment strategies because they pass through the BBB and have the potential to deliver molecules to target lesions. Meanwhile, Exos have decreased safety risks from intravenous injection or orthotopic transplantation of viable cells, such as microvascular occlusion or imbalanced growth of transplanted cells. These unique characteristics also create Exos contents, especially Exos-derived microRNAs, as appealing biomarkers in TBI. In this review, we explore the potential impact of cell-derived Exos and exosome-derived microRNAs on the diagnosis, therapy, and prognosis prediction of TBI. The associated challenges and opportunities are also discussed.
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134
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Sobolczyk M, Boczek T. Astrocytic Calcium and cAMP in Neurodegenerative Diseases. Front Cell Neurosci 2022; 16:889939. [PMID: 35663426 PMCID: PMC9161693 DOI: 10.3389/fncel.2022.889939] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/05/2022] [Indexed: 12/18/2022] Open
Abstract
It is commonly accepted that the role of astrocytes exceeds far beyond neuronal scaffold and energy supply. Their unique morphological and functional features have recently brough much attention as it became evident that they play a fundamental role in neurotransmission and interact with synapses. Synaptic transmission is a highly orchestrated process, which triggers local and transient elevations in intracellular Ca2+, a phenomenon with specific temporal and spatial properties. Presynaptic activation of Ca2+-dependent adenylyl cyclases represents an important mechanism of synaptic transmission modulation. This involves activation of the cAMP-PKA pathway to regulate neurotransmitter synthesis, release and storage, and to increase neuroprotection. This aspect is of paramount importance for the preservation of neuronal survival and functionality in several pathological states occurring with progressive neuronal loss. Hence, the aim of this review is to discuss mutual relationships between cAMP and Ca2+ signaling and emphasize those alterations at the Ca2+/cAMP crosstalk that have been identified in neurodegenerative disorders, such as Alzheimer's and Parkinson's disease.
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135
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Tsai YL, Yen CT, Wang YF. Astrocyte Dysregulation and Calcium Ion Imbalance May Link the Development of Osteoporosis and Alzheimer’s Disease. J Alzheimers Dis 2022; 88:439-445. [DOI: 10.3233/jad-220218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The typical symptoms of patients with Alzheimer’s disease (AD) are amyloid-β (Aβ) plaques and tau hyperphosphorylation. However, recent studies show that these symptoms are not the cause of the disease but are generated after the pathogenesis. Compared with other types of dementia, AD has the obvious features of pineal gland calcification and decreased melatonin production. The pineal gland is mainly composed of pinealocytes that release melatonin and astrocytes. Astrocytes function to maintain a balanced concentration of calcium ions, provide nerve cell nutrients, and migrate nutrients in vivo. Calcium ions are among the most important neurotransmitters. Once triggered, a calcium wave can be formed between astrocytes to activate other astrocytes to transmit information. Most calcium is stored in the skeleton. Bone tissue is composed mainly of osteocytes, osteoblasts, and osteoclasts. Of these, osteocyte is a kind of astrocyte which regulates the activity of osteoclasts and osteoblasts. The pineal gland is composed mainly of astrocytes; osteocytes are also a kind of astrocyte. Therefore, we conclude that when astrocytes are gradually disabled, calcium may be lost from the bones, prompting osteoporosis. The calcium ions then released into the blood may accumulate and cause ectopic calcification in the pineal gland, which promotes the occurrence of AD. Finally, this study used aspects of drugs and hormones (bone and calcium metabolism hormones and melatonin) to infer the hypothesis, which proposes that astrocyte dysregulation promotes the long-term imbalance of calcium ions in vivo and leads to osteoporosis and AD.
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Affiliation(s)
- Yi-Liang Tsai
- Department of Nuclear Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
- Department of Medical Research, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
| | - Chieh-Tsung Yen
- Department of Neurology, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
| | - Yuh-Feng Wang
- Department of Nuclear Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
- Department of Radiology, School of Medicine, Tzu Chi University, Hualien, Taiwan
- Center of Preventive Medicine, Dalin Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Chiayi, Taiwan
- Department of Nuclear Medicine, Taipei Veterans General Hospital, Taipei, Taiwan
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136
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Nakajima H, Fujita S, Kakae M, Nagayasu K, Oh-Hora M, Shirakawa H, Kaneko S. Orai2 channel regulates prostaglandin E 2 production in TNFα/IL1α-stimulated astrocytes. Glia 2022; 70:1666-1680. [PMID: 35506586 DOI: 10.1002/glia.24188] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 04/19/2022] [Accepted: 04/25/2022] [Indexed: 01/04/2023]
Abstract
Astrocytes are glial cells that serve homeostatic functions in the central nervous system (CNS). Recent research, however, suggests that under pathological conditions, astrocytes are stimulated by various factors and actively participate in CNS inflammation. In the present study, we found that astrocytes upregulate various inflammatory factors including prostaglandin E2 (PGE2 ) by co-stimulation with tumor necrosis factor-alpha (TNFα) and interleukin-1alpha (IL1α). These TNFα/IL1α-stimulated astrocytes also showed increased Ca2+ release from the endoplasmic reticulum (ER) and increased expression of Orai2, a member of the store-operated calcium channel (SOCC) family. To reveal the role of Orai2, we used astrocytes in which Orai2 was knocked-down (KD) or knocked-out (KO). The expression of the prostaglandin E synthase Ptges and the production of PGE2 were higher in Orai2-KD astrocytes than in WT astrocytes when stimulated with TNFα and IL1α. Orai2-KO astrocytes also showed increased expression of Ptges and increased PGE2 production. The expression of Ptgs2, another PGE2 synthetic enzyme, was also upregulated in Orai2-KO astrocytes. Moreover, Orai2-KO astrocytes showed increased store-operated calcium entry (SOCE) and increased Orai1 expression. These results suggest that Orai2 is upregulated in TNFα/IL1α-stimulated astrocytes and reduces PGE2 production to some extent, modulating CNS inflammation. Our findings may aid in understanding how astrocytes are associated with inflammatory responses, and the identification of new targets that modulate astrocytic reactivity.
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Affiliation(s)
- Hiroki Nakajima
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Sayaka Fujita
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Masashi Kakae
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Kazuki Nagayasu
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Masatsugu Oh-Hora
- Department of Biochemistry, Juntendo University School of Medicine, Tokyo, Japan.,Division of Molecular Immunology, Research Center for Infectious Diseases, Medical Institute of Bioregulation, Kyusyu University, Fukuoka, Japan.,Laboratory of Molecular Immunology, Immunology Frontier Research Center, Osaka University, Suita, Japan
| | - Hisashi Shirakawa
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
| | - Shuji Kaneko
- Department of Molecular Pharmacology, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan
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137
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Palabas T, Longtin A, Ghosh D, Uzuntarla M. Controlling the spontaneous firing behavior of a neuron with astrocyte. CHAOS (WOODBURY, N.Y.) 2022; 32:051101. [PMID: 35649970 DOI: 10.1063/5.0093234] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/27/2022] [Accepted: 04/18/2022] [Indexed: 06/15/2023]
Abstract
Mounting evidence in recent years suggests that astrocytes, a sub-type of glial cells, not only serve metabolic and structural support for neurons and synapses but also play critical roles in the regulation of proper functioning of the nervous system. In this work, we investigate the effect of astrocytes on the spontaneous firing activity of a neuron through a combined model that includes a neuron-astrocyte pair. First, we show that an astrocyte may provide a kind of multistability in neuron dynamics by inducing different firing modes such as random and bursty spiking. Then, we identify the underlying mechanism of this behavior and search for the astrocytic factors that may have regulatory roles in different firing regimes. More specifically, we explore how an astrocyte can participate in the occurrence and control of spontaneous irregular spiking activity of a neuron in random spiking mode. Additionally, we systematically investigate the bursty firing regime dynamics of the neuron under the variation of biophysical facts related to the intracellular environment of the astrocyte. It is found that an astrocyte coupled to a neuron can provide a control mechanism for both spontaneous firing irregularity and burst firing statistics, i.e., burst regularity and size.
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Affiliation(s)
- Tugba Palabas
- Department of Biomedical Engineering, Zonguldak Bulent Ecevit University, 67100 Zonguldak, Turkey
| | - Andre Longtin
- Department of Physics, University of Ottawa, Ottawa, Ontario K1N 6N5, Canada
| | - Dibakar Ghosh
- Physics and Applied Mathematics Unit, Indian Statistical Institute, Kolkata 700108, India
| | - Muhammet Uzuntarla
- Department of Bioengineering, Gebze Technical University, 41400 Kocaeli, Turkey
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138
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Allen M, Huang BS, Notaras MJ, Lodhi A, Barrio-Alonso E, Lituma PJ, Wolujewicz P, Witztum J, Longo F, Chen M, Greening DW, Klann E, Ross ME, Liston C, Colak D. Astrocytes derived from ASD individuals alter behavior and destabilize neuronal activity through aberrant Ca 2+ signaling. Mol Psychiatry 2022; 27:2470-2484. [PMID: 35365802 PMCID: PMC9135629 DOI: 10.1038/s41380-022-01486-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 02/01/2022] [Accepted: 02/11/2022] [Indexed: 01/08/2023]
Abstract
The cellular mechanisms of autism spectrum disorder (ASD) are poorly understood. Cumulative evidence suggests that abnormal synapse function underlies many features of this disease. Astrocytes regulate several key neuronal processes, including the formation of synapses and the modulation of synaptic plasticity. Astrocyte abnormalities have also been identified in the postmortem brain tissue of ASD individuals. However, it remains unclear whether astrocyte pathology plays a mechanistic role in ASD, as opposed to a compensatory response. To address this, we combined stem cell culturing with transplantation techniques to determine disease-specific properties inherent to ASD astrocytes. We demonstrate that ASD astrocytes induce repetitive behavior as well as impair memory and long-term potentiation when transplanted into the healthy mouse brain. These in vivo phenotypes were accompanied by reduced neuronal network activity and spine density caused by ASD astrocytes in hippocampal neurons in vitro. Transplanted ASD astrocytes also exhibit exaggerated Ca2+ fluctuations in chimeric brains. Genetic modulation of evoked Ca2+ responses in ASD astrocytes modulates behavior and neuronal activity deficits. Thus, this study determines that astrocytes derived from ASD iPSCs are sufficient to induce repetitive behavior as well as cognitive deficit, suggesting a previously unrecognized primary role for astrocytes in ASD.
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Affiliation(s)
- Megan Allen
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Ben S Huang
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA.,Department of Psychiatry, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Michael J Notaras
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Aiman Lodhi
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Estibaliz Barrio-Alonso
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Pablo J Lituma
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Paul Wolujewicz
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Jonathan Witztum
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Francesco Longo
- Center for Neural Science, New York University, New York, NY, USA
| | - Maoshan Chen
- Molecular Proteomics, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, VIC, Australia.,Baker Department of Cardiovascular Research, Translation and Implementation, La Trobe University, Melbourne, VIC, Australia.,Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - David W Greening
- Molecular Proteomics, Baker Heart and Diabetes Institute, Melbourne, VIC, Australia.,Baker Department of Cardiometabolic Health, The University of Melbourne, Melbourne, VIC, Australia.,Baker Department of Cardiovascular Research, Translation and Implementation, La Trobe University, Melbourne, VIC, Australia.,Central Clinical School, Monash University, Melbourne, VIC, Australia
| | - Eric Klann
- Center for Neural Science, New York University, New York, NY, USA
| | - M Elizabeth Ross
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Conor Liston
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA.,Department of Psychiatry, Weill Cornell Medicine, Cornell University, New York, NY, USA
| | - Dilek Colak
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, Cornell University, New York, NY, USA. .,Gale and Ira Drukier Institute for Children's Health, Weill Cornell Medicine, Cornell University, New York, NY, USA.
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139
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Linne ML, Aćimović J, Saudargiene A, Manninen T. Neuron-Glia Interactions and Brain Circuits. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1359:87-103. [PMID: 35471536 DOI: 10.1007/978-3-030-89439-9_4] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Recent evidence suggests that glial cells take an active role in a number of brain functions that were previously attributed solely to neurons. For example, astrocytes, one type of glial cells, have been shown to promote coordinated activation of neuronal networks, modulate sensory-evoked neuronal network activity, and influence brain state transitions during development. This reinforces the idea that astrocytes not only provide the "housekeeping" for the neurons, but that they also play a vital role in supporting and expanding the functions of brain circuits and networks. Despite this accumulated knowledge, the field of computational neuroscience has mostly focused on modeling neuronal functions, ignoring the glial cells and the interactions they have with the neurons. In this chapter, we introduce the biology of neuron-glia interactions, summarize the existing computational models and tools, and emphasize the glial properties that may be important in modeling brain functions in the future.
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Affiliation(s)
- Marja-Leena Linne
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland.
| | - Jugoslava Aćimović
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
| | - Ausra Saudargiene
- Neuroscience Institute, Lithuanian University of Health Sciences, Kaunas, Lithuania.,Department of Informatics, Vytautas Magnus University, Kaunas, Lithuania
| | - Tiina Manninen
- Faculty of Medicine and Health Technology, Tampere University, Tampere, Finland
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140
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Badia-Soteras A, de Vries J, Dykstra W, Broersen LM, Verkuyl JM, Smit AB, Verheijen MHG. High-Throughput Analysis of Astrocyte Cultures Shows Prevention of Reactive Astrogliosis by the Multi-Nutrient Combination Fortasyn Connect. Cells 2022; 11:cells11091428. [PMID: 35563732 PMCID: PMC9099974 DOI: 10.3390/cells11091428] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2021] [Revised: 04/07/2022] [Accepted: 04/20/2022] [Indexed: 12/23/2022] Open
Abstract
Astrocytes are specialized glial cells that tile the central nervous system (CNS) and perform numerous essential functions. Astrocytes react to various forms of CNS insults by altering their morphology and molecular profile, through a process known as reactive astrogliosis. Accordingly, astrocyte reactivity is apparent in many neurodegenerative diseases, among which one is Alzheimer’s disease (AD). Recent clinical trials on early-stage AD have demonstrated that Fortasyn Connect (FC), a multi-nutrient combination providing specific precursors and cofactors for phospholipid synthesis, helps to maintain neuronal functional connectivity and cognitive performance of patients. Several studies have shown that FC may act through its effects on neuronal survival and synaptogenesis, leading to reduced astrocyte reactivity, but whether FC can directly counteract astrocyte reactivity remains to be elucidated. Hence, we developed an in vitro model of reactive astrogliosis using the pro-inflammatory cytokines TNF-α and IFN-γ together with an automated high-throughput assay (AstroScan) to quantify molecular and morphological changes that accompany reactive astrogliosis. Next, we showed that FC is potent in preventing cytokine-induced reactive astrogliosis, a finding that might be of high relevance to understand the beneficial effects of FC-based interventions in the context of neurodegenerative diseases.
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Affiliation(s)
- Aina Badia-Soteras
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Faculty of Earth and Life Sciences, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands; (A.B.-S.); (J.d.V.); (W.D.); (A.B.S.)
| | - Janneke de Vries
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Faculty of Earth and Life Sciences, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands; (A.B.-S.); (J.d.V.); (W.D.); (A.B.S.)
| | - Werner Dykstra
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Faculty of Earth and Life Sciences, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands; (A.B.-S.); (J.d.V.); (W.D.); (A.B.S.)
| | - Laus M. Broersen
- Danone Nutricia Research, 3584 CT Utrecht, The Netherlands; (L.M.B.); (J.M.V.)
| | - Jan Martin Verkuyl
- Danone Nutricia Research, 3584 CT Utrecht, The Netherlands; (L.M.B.); (J.M.V.)
| | - August B. Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Faculty of Earth and Life Sciences, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands; (A.B.-S.); (J.d.V.); (W.D.); (A.B.S.)
| | - Mark H. G. Verheijen
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Faculty of Earth and Life Sciences, Vrije Universiteit, 1081 HV Amsterdam, The Netherlands; (A.B.-S.); (J.d.V.); (W.D.); (A.B.S.)
- Correspondence:
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141
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Astrocytes Modulate Somatostatin Interneuron Signaling in the Visual Cortex. Cells 2022; 11:cells11091400. [PMID: 35563706 PMCID: PMC9102536 DOI: 10.3390/cells11091400] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Revised: 04/14/2022] [Accepted: 04/18/2022] [Indexed: 02/05/2023] Open
Abstract
At glutamatergic synapses, astrocytes respond to the neurotransmitter glutamate with intracellular Ca2+ elevations and the release of gliotransmitters that modulate synaptic transmission. While the functional interactions between neurons and astrocytes have been intensively studied at glutamatergic synapses, the role of astrocytes at GABAergic synapses has been less investigated. In the present study, we combine optogenetics with 2-photon Ca2+ imaging experiments and patch-clamp recording techniques to investigate the signaling between Somatostatin (SST)-releasing GABAergic interneurons and astrocytes in brain slice preparations from the visual cortex (VCx). We found that an intense stimulation of SST interneurons evokes Ca2+ elevations in astrocytes that fundamentally depend on GABAB receptor (GABABR) activation, and that this astrocyte response is modulated by the neuropeptide somatostatin. After episodes of SST interneuron hyperactivity, we also observed a long-lasting reduction of the inhibitory postsynaptic current (IPSC) amplitude onto pyramidal neurons (PNs). This reduction of inhibitory tone (i.e., disinhibition) is counterbalanced by the activation of astrocytes that upregulate SST interneuron-evoked IPSC amplitude by releasing ATP that, after conversion to adenosine, activates A1Rs. Our results describe a hitherto unidentified modulatory mechanism of inhibitory transmission to VCx layer II/III PNs that involves the functional recruitment of astrocytes by SST interneuron signaling.
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142
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Bistability and Chaos Emergence in Spontaneous Dynamics of Astrocytic Calcium Concentration. MATHEMATICS 2022. [DOI: 10.3390/math10081337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In this work, we consider a mathematical model describing spontaneous calcium signaling in astrocytes. Based on biologically relevant principles, this model simulates experimentally observed calcium oscillations and can predict the emergence of complicated dynamics. Using analytical and numerical analysis, various attracting sets were found and investigated. Employing bifurcation theory analysis, we examined steady state solutions, bistability, simple and complicated periodic limit cycles and also chaotic attractors. We found that astrocytes possess a variety of complex dynamical modes, including chaos and multistability, that can further provide different modulations of neuronal circuits, enhancing their plasticity and flexibility.
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143
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Cheng YT, Woo J, Deneen B. Sculpting Astrocyte Diversity through Circuits and Transcription. Neuroscientist 2022:10738584221082620. [PMID: 35373633 PMCID: PMC9526762 DOI: 10.1177/10738584221082620] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Astrocytes are the most abundant glial cell in the central nervous system and occupy a wide range of roles that are essential for brain function. Over the past few years, evidence has emerged that astrocytes exhibit cellular and molecular heterogeneity, raising the possibility that subsets of astrocytes are functionally distinct and that transcriptional mechanisms are involved in encoding this prospective diversity. In this review, we focus on three emerging areas of astrocyte biology: region-specific circuit regulation, molecular diversity, and transcriptional regulation. This review highlights our nascent understanding of how molecular diversity is converted to functional diversity of astrocytes through the lens of brain region-specific circuits. We articulate our understanding of how transcriptional mechanisms regulate this diversity and key areas that need further exploration to achieve the overarching goal of a functional taxonomy of astrocytes in the brain.
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Affiliation(s)
- Yi-Ting Cheng
- Program in Developmental Biology, Baylor College of Medicine, Houston, Houston, TX, USA.,Center for Cell and Gene Therapy, Texas Children's Hospital, Houston, TX, USA
| | - Junsung Woo
- Center for Cell and Gene Therapy, Texas Children's Hospital, Houston, TX, USA
| | - Benjamin Deneen
- Program in Developmental Biology, Baylor College of Medicine, Houston, Houston, TX, USA.,Center for Cell and Gene Therapy, Texas Children's Hospital, Houston, TX, USA.,Department of Neurosurgery, Baylor College of Medicine, Houston, TX, USA
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144
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Rieder P, Gobbo D, Stopper G, Welle A, Damo E, Kirchhoff F, Scheller A. Astrocytes and Microglia Exhibit Cell-Specific Ca2+ Signaling Dynamics in the Murine Spinal Cord. Front Mol Neurosci 2022; 15:840948. [PMID: 35431801 PMCID: PMC9006623 DOI: 10.3389/fnmol.2022.840948] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/22/2022] [Indexed: 12/31/2022] Open
Abstract
The spinal cord is the main pathway connecting brain and peripheral nervous system. Its functionality relies on the orchestrated activity of both neurons and glial cells. To date, most advancement in understanding the spinal cord inner mechanisms has been made either by in vivo exposure of its dorsal surface through laminectomy or by acute ex vivo slice preparation, likely affecting spinal cord physiology in virtue of the necessary extensive manipulation of the spinal cord tissue. This is especially true of cells immediately responding to alterations of the surrounding environment, such as microglia and astrocytes, reacting within seconds or minutes and for up to several days after the original insult. Ca2+ signaling is considered one of the most immediate, versatile, and yet elusive cellular responses of glia. Here, we induced the cell-specific expression of the genetically encoded Ca2+ indicator GCaMP3 to evaluate spontaneous intracellular Ca2+ signaling in astrocytes and microglia. Ca2+ signals were then characterized in acute ex vivo (both gray and white matter) as well as in chronic in vivo (white matter) preparations using MSparkles, a MATLAB-based software for automatic detection and analysis of fluorescence events. As a result, we were able to segregate distinct astroglial and microglial Ca2+ signaling patterns along with method-specific Ca2+ signaling alterations, which must be taken into consideration in the reliable evaluation of any result obtained in physiological as well as pathological conditions. Our study revealed a high degree of Ca2+ signaling diversity in glial cells of the murine spinal cord, thus adding to the current knowledge of the astonishing glial heterogeneity and cell-specific Ca2+ dynamics in non-neuronal networks.
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Affiliation(s)
- Phillip Rieder
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Davide Gobbo
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Gebhard Stopper
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Anna Welle
- Department of Genetics and Epigenetics, University of Saarland, Saarbrücken, Germany
| | - Elisa Damo
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
- Institute of Pharmacology, Medical Faculty Heidelberg, Heidelberg University, Heidelberg, Germany
| | - Frank Kirchhoff
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Anja Scheller
- Department of Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
- *Correspondence: Anja Scheller,
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145
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Huffels CFM, Osborn LM, Cappaert NLM, Hol EM. Calcium signaling in individual APP/PS1 mouse dentate gyrus astrocytes increases ex vivo with Aβ pathology and age without affecting astrocyte network activity. J Neurosci Res 2022; 100:1281-1295. [PMID: 35293016 PMCID: PMC9314019 DOI: 10.1002/jnr.25042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Revised: 01/12/2022] [Accepted: 02/22/2022] [Indexed: 01/24/2023]
Abstract
Astrocytes are critical for healthy brain function. In Alzheimer's disease, astrocytes become reactive, which affects their signaling properties. Here, we measured spontaneous calcium transients ex vivo in hippocampal astrocytes in brain slices containing the dentate gyrus of 6- (6M) and 9-month-old (9M) APPswe/PSEN1dE9 (APP/PS1) mice. We investigated the frequency and duration of calcium transients in relation to aging, amyloid-β (Aβ) pathology, and the proximity of the astrocyte to Aβ plaques. The 6M APP/PS1 astrocytes showed no change in spontaneous calcium-transient properties compared to wild-type (WT) astrocytes. 9M APP/PS1 astrocytes, however, showed more hyperactivity compared to WT, characterized by increased spontaneous calcium transients that were longer in duration. Our data also revealed an effect of aging, as 9M astrocytes overall showed an increase in calcium activity compared to 6M astrocytes. Subsequent calcium-wave analysis showed an increase in sequential calcium transients (i.e., calcium waves) in 9M astrocytes, suggesting increased network activity ex vivo. Further analysis using null models revealed that this network effect is caused by chance, due to the increased number of spontaneous transients. Our findings show that alterations in calcium signaling in individual hippocampal astrocytes of APP/PS1 mice are subject to both aging and Aβ pathology but these do not lead to a change in astrocyte network activity. These alterations in calcium dynamics of astrocytes may help to understand changes in neuronal physiology leading to cognitive decline and ultimately dementia.
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Affiliation(s)
- Christiaan F M Huffels
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
| | - Lana M Osborn
- Swammerdam Institute for Life Sciences, Center for Neuroscience, Cellular and Computational Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - Natalie L M Cappaert
- Swammerdam Institute for Life Sciences, Center for Neuroscience, Cellular and Computational Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - Elly M Hol
- Department of Translational Neuroscience, University Medical Center Utrecht Brain Center, Utrecht University, Utrecht, The Netherlands
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146
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Jackson JG, Krizman E, Takano H, Lee M, Choi GH, Putt ME, Robinson MB. Activation of Glutamate Transport Increases Arteriole Diameter in v ivo: Implications for Neurovascular Coupling. Front Cell Neurosci 2022; 16:831061. [PMID: 35308116 PMCID: PMC8930833 DOI: 10.3389/fncel.2022.831061] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 01/24/2022] [Indexed: 11/21/2022] Open
Abstract
In order to meet the energetic demands of cell-to-cell signaling, increases in local neuronal signaling are matched by a coordinated increase in local blood flow, termed neurovascular coupling. Multiple different signals from neurons, astrocytes, and pericytes contribute to this control of blood flow. Previously, several groups demonstrated that inhibition/ablation of glutamate transporters attenuates the neurovascular response. However, it was not determined if glutamate transporter activation was sufficient to increase blood flow. Here, we used multiphoton imaging to monitor the diameter of fluorescently labeled cortical arterioles in anesthetized C57/B6J mice. We delivered vehicle, glutamate transporter substrates, or a combination of a glutamate transporter substrate with various pharmacologic agents via a glass micropipette while simultaneously visualizing changes in arteriole diameter. We developed a novel image analysis method to automate the measurement of arteriole diameter in these time-lapse analyses. Using this workflow, we first conducted pilot experiments in which we focally applied L-glutamate, D-aspartate, or L-threo-hydroxyaspartate (L-THA) and measured arteriole responses as proof of concept. We subsequently applied the selective glutamate transport substrate L-THA (applied at concentrations that do not activate glutamate receptors). We found that L-THA evoked a significantly larger dilation than that observed with focal saline application. This response was blocked by co-application of the potent glutamate transport inhibitor, L-(2S,3S)-3-[3-[4-(trifluoromethyl)-benzoylamino]benzyloxy]-aspartate (TFB-TBOA). Conversely, we were unable to demonstrate a reduction of this effect through co-application of a cocktail of glutamate and GABA receptor antagonists. These studies provide the first direct evidence that activation of glutamate transport is sufficient to increase arteriole diameter. We explored potential downstream mechanisms mediating this transporter-mediated dilation by using a Ca2+ chelator or inhibitors of reversed-mode Na+/Ca2+ exchange, nitric oxide synthetase, or cyclo-oxygenase. The estimated effects and confidence intervals suggested some form of inhibition for a number of these inhibitors. Limitations to our study design prevented definitive conclusions with respect to these downstream inhibitors; these limitations are discussed along with possible next steps. Understanding the mechanisms that control blood flow are important because changes in blood flow/energy supply are implicated in several neurodegenerative disorders and are used as a surrogate measure of neuronal activity in widely used techniques such as functional magnetic resonance imaging (fMRI).
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Affiliation(s)
- Joshua G. Jackson
- Children’s Hospital of Philadelphia, Philadelphia, PA, United States
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA, United States
| | - Elizabeth Krizman
- Children’s Hospital of Philadelphia, Philadelphia, PA, United States
- Department of Pediatrics, University of Pennsylvania, Philadelphia, PA, United States
| | - Hajime Takano
- Children’s Hospital of Philadelphia, Philadelphia, PA, United States
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, United States
| | - Meredith Lee
- Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Grace H. Choi
- Department of Biostatistics, Epidemiology & Informatics, University of Pennsylvania, Philadelphia, PA, United States
| | - Mary E. Putt
- Department of Biostatistics, Epidemiology & Informatics, University of Pennsylvania, Philadelphia, PA, United States
| | - Michael B. Robinson
- Children’s Hospital of Philadelphia, Philadelphia, PA, United States
- Department of Systems Pharmacology and Translational Therapeutics, University of Pennsylvania, Philadelphia, PA, United States
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147
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Abstract
Hippocampal place cells, which display location-specific activity, are known to encode spatial information. A recent study in PLOS Biology by Curreli and colleagues shows that hippocampal astrocytes are implicated in encoding complementary spatial information, suggesting the existence of glial place cells.
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Affiliation(s)
- Xinzhu Yu
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, Illinois, United States of America
- * E-mail:
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148
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Curreli S, Bonato J, Romanzi S, Panzeri S, Fellin T. Complementary encoding of spatial information in hippocampal astrocytes. PLoS Biol 2022; 20:e3001530. [PMID: 35239646 PMCID: PMC8893713 DOI: 10.1371/journal.pbio.3001530] [Citation(s) in RCA: 22] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Accepted: 01/05/2022] [Indexed: 01/28/2023] Open
Abstract
Calcium dynamics into astrocytes influence the activity of nearby neuronal structures. However, because previous reports show that astrocytic calcium signals largely mirror neighboring neuronal activity, current information coding models neglect astrocytes. Using simultaneous two-photon calcium imaging of astrocytes and neurons in the hippocampus of mice navigating a virtual environment, we demonstrate that astrocytic calcium signals encode (i.e., statistically reflect) spatial information that could not be explained by visual cue information. Calcium events carrying spatial information occurred in topographically organized astrocytic subregions. Importantly, astrocytes encoded spatial information that was complementary and synergistic to that carried by neurons, improving spatial position decoding when astrocytic signals were considered alongside neuronal ones. These results suggest that the complementary place dependence of localized astrocytic calcium signals may regulate clusters of nearby synapses, enabling dynamic, context-dependent variations in population coding within brain circuits.
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Affiliation(s)
- Sebastiano Curreli
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, Genova, Italy
- Neural Coding Laboratory, Istituto Italiano di Tecnologia, Genova, Italy
| | - Jacopo Bonato
- Neural Coding Laboratory, Istituto Italiano di Tecnologia, Genova, Italy
- Neural Computation Laboratory, Istituto Italiano di Tecnologia, Rovereto, Italy
- Department of Pharmacy and Biotechnology, University of Bologna, Bologna, Italy
| | - Sara Romanzi
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, Genova, Italy
- Neural Coding Laboratory, Istituto Italiano di Tecnologia, Genova, Italy
- University of Genova, Genova, Italy
| | - Stefano Panzeri
- Neural Coding Laboratory, Istituto Italiano di Tecnologia, Genova, Italy
- Neural Computation Laboratory, Istituto Italiano di Tecnologia, Rovereto, Italy
- Department of Excellence for Neural Information Processing, Center for Molecular Neurobiology (ZMNH), University Medical Center Hamburg-Eppendorf (UKE), Hamburg, Germany
| | - Tommaso Fellin
- Optical Approaches to Brain Function Laboratory, Istituto Italiano di Tecnologia, Genova, Italy
- Neural Coding Laboratory, Istituto Italiano di Tecnologia, Genova, Italy
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149
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Del Franco AP, Chiang PP, Newman EA. Dilation of cortical capillaries is not related to astrocyte calcium signaling. Glia 2022; 70:508-521. [PMID: 34767261 PMCID: PMC8732319 DOI: 10.1002/glia.24119] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 10/12/2021] [Accepted: 10/31/2021] [Indexed: 12/30/2022]
Abstract
The brain requires an adequate supply of oxygen and nutrients to maintain proper function as neuronal activity varies. This is achieved, in part, through neurovascular coupling mechanisms that mediate local increases in blood flow through the dilation of arterioles and capillaries. The role of astrocytes in mediating this functional hyperemia response is controversial. Specifically, the function of astrocyte Ca2+ signaling is unclear. Cortical arterioles dilate in the absence of astrocyte Ca2+ signaling, but previous work suggests that Ca2+ increases are necessary for capillary dilation. This question has not been fully addressed in vivo, however, and we have reexamined the role of astrocyte Ca2+ signaling in vessel dilation in the barrel cortex of awake, behaving mice. We recorded evoked vessel dilations and astrocyte Ca2+ signaling in response to whisker stimulation. Experiments were carried out on WT and IP3R2 KO mice, a transgenic model where astrocyte Ca2+ signaling is substantially reduced. Compared to WT mice at rest, Ca2+ signaling in astrocyte endfeet contacting capillaries increased by 240% when whisker stimulation evoked running. In contrast, Ca2+ signaling was reduced to 9% of WT values in IP3R2 KO mice. In all three conditions, however, the amplitude of capillary dilation was largely unchanged. In addition, the latency to the onset of astrocyte Ca2+ signaling lagged behind dilation onset in most trials, although a subset of rapid onset Ca2+ events with latencies as short as 0.15 s occurred. In summary, we found that whisker stimulation-evoked capillary dilations occurred independent of astrocyte Ca2+ increases in the cerebral cortex.
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Affiliation(s)
- Armani P Del Franco
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
| | - Pei-Pei Chiang
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
| | - Eric A Newman
- Department of Neuroscience, University of Minnesota, Minneapolis, Minnesota, USA
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Amato S, Averna M, Guidolin D, Pedrazzi M, Pelassa S, Capraro M, Passalacqua M, Bozzo M, Gatta E, Anderlini D, Maura G, Agnati LF, Cervetto C, Marcoli M. Heterodimer of A2A and Oxytocin Receptors Regulating Glutamate Release in Adult Striatal Astrocytes. Int J Mol Sci 2022; 23:ijms23042326. [PMID: 35216441 PMCID: PMC8879615 DOI: 10.3390/ijms23042326] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2022] [Revised: 02/16/2022] [Accepted: 02/18/2022] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Roles of astrocytes in the modulatory effects of oxytocin (OT) in central nervous system are increasingly considered. Nevertheless, OT effects on gliotransmitter release have been neglected. METHODS In purified astrocyte processes from adult rat striatum, we assessed OT receptor (OTR) and adenosine A2A receptor expression by confocal analysis. The effects of receptors activation on glutamate release from the processes were evaluated; A2A-OTR heteromerization was assessed by co-immunoprecipitation and PLA. Structure of the possible heterodimer of A2A and OT receptors was estimated by a bioinformatic approach. RESULTS Both A2A and OT receptors were expressed on the same astrocyte processes. Evidence for A2A-OTR receptor-receptor interaction was obtained by measuring the release of glutamate: OT inhibited the evoked glutamate release, while activation of A2A receptors, per se ineffective, abolished the OT effect. Biochemical and biophysical evidence for A2A-OTR heterodimers on striatal astrocytes was also obtained. The residues in the transmembrane domains 4 and 5 of both receptors are predicted to be mainly involved in the heteromerization. CONCLUSIONS When considering effects of OT in striatum, modulation of glutamate release from the astrocyte processes and of glutamatergic synapse functioning, and the interaction with A2A receptors on the astrocyte processes should be taken into consideration.
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Affiliation(s)
- Sarah Amato
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genova, Italy; (S.A.); (S.P.); (G.M.)
| | - Monica Averna
- Department of Experimental Medicine, Section of Biochemistry, University of Genova, Viale Benedetto XV 1, 16132 Genova, Italy; (M.A.); (M.P.); (M.C.); (M.P.)
| | - Diego Guidolin
- Department of Neuroscience, University of Padova, Via Gabelli 63, 35122 Padova, Italy;
| | - Marco Pedrazzi
- Department of Experimental Medicine, Section of Biochemistry, University of Genova, Viale Benedetto XV 1, 16132 Genova, Italy; (M.A.); (M.P.); (M.C.); (M.P.)
| | - Simone Pelassa
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genova, Italy; (S.A.); (S.P.); (G.M.)
| | - Michela Capraro
- Department of Experimental Medicine, Section of Biochemistry, University of Genova, Viale Benedetto XV 1, 16132 Genova, Italy; (M.A.); (M.P.); (M.C.); (M.P.)
| | - Mario Passalacqua
- Department of Experimental Medicine, Section of Biochemistry, University of Genova, Viale Benedetto XV 1, 16132 Genova, Italy; (M.A.); (M.P.); (M.C.); (M.P.)
- Italian Institute of Biostructures and Biosystems, Viale delle Medaglie d’Oro 305, 00136 Roma, Italy
| | - Matteo Bozzo
- Department of Earth, Environment and Life Sciences, University of Genova, Viale Benedetto XV 5, 16132 Genova, Italy;
| | - Elena Gatta
- DIFILAB, Department of Physics, University of Genoa, Via Dodecaneso 33, 16146 Genova, Italy;
| | - Deanna Anderlini
- Centre for Sensorimotor Performance, The University of Queensland, Brisbane, Blair Drive, St. Lucia, QLD 4067, Australia;
| | - Guido Maura
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genova, Italy; (S.A.); (S.P.); (G.M.)
| | - Luigi F. Agnati
- Department of Biomedical, Metabolic Sciences and Neuroscience, University of Modena and Reggio Emilia, Via Campi 287, 41125 Modena, Italy;
| | - Chiara Cervetto
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genova, Italy; (S.A.); (S.P.); (G.M.)
- Correspondence: (C.C.); (M.M.)
| | - Manuela Marcoli
- Department of Pharmacy, Section of Pharmacology and Toxicology, University of Genova, Viale Cembrano 4, 16148 Genova, Italy; (S.A.); (S.P.); (G.M.)
- Center of Excellence for Biomedical Research, University of Genova, Viale Benedetto XV 9, 16132 Genova, Italy
- Correspondence: (C.C.); (M.M.)
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