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Zhang L, Wei J, Liu X, Li D, Pang X, Chen F, Cao H, Lei P. Gut microbiota-astrocyte axis: new insights into age-related cognitive decline. Neural Regen Res 2025; 20:990-1008. [PMID: 38989933 DOI: 10.4103/nrr.nrr-d-23-01776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Accepted: 03/04/2024] [Indexed: 07/12/2024] Open
Abstract
With the rapidly aging human population, age-related cognitive decline and dementia are becoming increasingly prevalent worldwide. Aging is considered the main risk factor for cognitive decline and acts through alterations in the composition of the gut microbiota, microbial metabolites, and the functions of astrocytes. The microbiota-gut-brain axis has been the focus of multiple studies and is closely associated with cognitive function. This article provides a comprehensive review of the specific changes that occur in the composition of the gut microbiota and microbial metabolites in older individuals and discusses how the aging of astrocytes and reactive astrocytosis are closely related to age-related cognitive decline and neurodegenerative diseases. This article also summarizes the gut microbiota components that affect astrocyte function, mainly through the vagus nerve, immune responses, circadian rhythms, and microbial metabolites. Finally, this article summarizes the mechanism by which the gut microbiota-astrocyte axis plays a role in Alzheimer's and Parkinson's diseases. Our findings have revealed the critical role of the microbiota-astrocyte axis in age-related cognitive decline, aiding in a deeper understanding of potential gut microbiome-based adjuvant therapy strategies for this condition.
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Affiliation(s)
- Lan Zhang
- Haihe Laboratory of Cell Ecosystem, Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Geriatrics Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - Jingge Wei
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, National Key Clinical Specialty, Tianjin Institute of Digestive Diseases, Tianjin Key Laboratory of Digestive Diseases, Tianjin, China
| | - Xilei Liu
- Department of Urology, Tianjin Medical University General Hospital, Tianjin, China
| | - Dai Li
- Haihe Laboratory of Cell Ecosystem, Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Geriatrics Institute, Tianjin Medical University General Hospital, Tianjin, China
| | - Xiaoqi Pang
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, National Key Clinical Specialty, Tianjin Institute of Digestive Diseases, Tianjin Key Laboratory of Digestive Diseases, Tianjin, China
| | - Fanglian Chen
- Tianjin Neurological Institution, Tianjin Medical University General Hospital, Tianjin, China
| | - Hailong Cao
- Department of Gastroenterology and Hepatology, Tianjin Medical University General Hospital, National Key Clinical Specialty, Tianjin Institute of Digestive Diseases, Tianjin Key Laboratory of Digestive Diseases, Tianjin, China
| | - Ping Lei
- Haihe Laboratory of Cell Ecosystem, Department of Geriatrics, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Geriatrics Institute, Tianjin Medical University General Hospital, Tianjin, China
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2
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Azevedo-Pereira RL, Aizman I, Nejadnik B. Mesenchymal Stem Cells Promote an Increase in Neuronal Oscillation via Glutamate Tonic Release. Neuroscience 2024; 552:76-88. [PMID: 38909673 DOI: 10.1016/j.neuroscience.2024.06.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 06/16/2024] [Accepted: 06/18/2024] [Indexed: 06/25/2024]
Abstract
Mesenchymal stromal cells (MSCs) hold therapeutic potential for neurological disorders, but their impact on neuronal activity remains unclear. We investigated the effects of SB623 cells (Notch-1 intracellular domain-transfected MSCs) and parental MSCs on human induced pluripotent stem cell (iPSC)-derived neurons using multi-electrode arrays. SB623 cells significantly increased neuronal activity and oscillation in a dose-dependent manner, surpassing astrocytes in promoting network bursts. Strikingly, glutamatergic neurons showed a rapid increase in activity and bursts compared to GABAergic neurons, suggesting glutamate release from SB623 cells. We confirmed this by finding high glutamate levels in SB623 cell conditioned medium, which were reduced by glutaminase inhibition. Glutamate release was further implicated by the reduced excitability in co-cultures with astrocytes, known glutamate scavengers. Our findings reveal a novel mechanism for MSCs: promoting neuronal activity and network formation through tonic glutamate release, with potential implications for MSC-based therapies.
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Affiliation(s)
| | - Irina Aizman
- SanBio Inc. Department of Research - In vitro, USA
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3
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Mishra S, Stany B, Das A, Kanagavel D, Vijayan M. A Comprehensive Review of Membrane Transporters and MicroRNA Regulation in Alzheimer's Disease. Mol Neurobiol 2024:10.1007/s12035-024-04135-2. [PMID: 38558361 DOI: 10.1007/s12035-024-04135-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 03/15/2024] [Indexed: 04/04/2024]
Abstract
Alzheimer's disease (AD) is a distressing neurodegenerative condition characterized by the accumulation of amyloid-beta (Aβ) plaques and tau tangles within the brain. The interconnectedness between membrane transporters (SLCs) and microRNAs (miRNAs) in AD pathogenesis has gained increasing attention. This review explores the localization, substrates, and functions of SLC transporters in the brain, emphasizing the roles of transporters for glutamate, glucose, nucleosides, and other essential compounds. The examination delves into the significance of SLCs in AD, their potential for drug development, and the intricate realm of miRNAs, encompassing their transcription, processing, functions, and regulation. MiRNAs have emerged as significant players in AD, including those associated with mitochondria and synapses. Furthermore, this review discusses the intriguing nexus of miRNAs targeting SLC transporters and their potential as therapeutic targets in AD. Finally, the review underscores the interaction between SLC transporters and miRNA regulation within the context of Alzheimer's disease, underscoring the need for further research in this area. This comprehensive review aims to shed light on the complex mechanisms underlying the causation of AD and provides insights into potential therapeutic approaches.
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Affiliation(s)
- Shatakshi Mishra
- School of Biosciences and Technology, Department of Biotechnology, VIT University, Vellore, Tamil Nadu, 632014, India
| | - B Stany
- School of Biosciences and Technology, Department of Biotechnology, VIT University, Vellore, Tamil Nadu, 632014, India
| | - Anushka Das
- School of Biosciences and Technology, Department of Biotechnology, VIT University, Vellore, Tamil Nadu, 632014, India
| | - Deepankumar Kanagavel
- School of Biosciences and Technology, Department of Biotechnology, VIT University, Vellore, Tamil Nadu, 632014, India.
| | - Murali Vijayan
- Department of Internal Medicine, Texas Tech University Health Sciences Center, 3601 4th Street, Lubbock, TX, 79430, USA.
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4
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Takahashi K, Sato K. The Conventional and Breakthrough Tool for the Study of L-Glutamate Transporters. MEMBRANES 2024; 14:77. [PMID: 38668105 PMCID: PMC11052088 DOI: 10.3390/membranes14040077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 02/26/2024] [Accepted: 03/21/2024] [Indexed: 04/28/2024]
Abstract
In our recent report, we clarified the direct interaction between the excitatory amino acid transporter (EAAT) 1/2 and polyunsaturated fatty acids (PUFAs) by applying electrophysiological and molecular biological techniques to Xenopus oocytes. Xenopus oocytes have a long history of use in the scientific field, but they are still attractive experimental systems for neuropharmacological studies. We will therefore summarize the pharmacological significance, advantages (especially in the study of EAAT2), and experimental techniques that can be applied to Xenopus oocytes; our new findings concerning L-glutamate (L-Glu) transporters and PUFAs; and the significant outcomes of our data. The data obtained from electrophysiological and molecular biological studies of Xenopus oocytes have provided us with further important questions, such as whether or not some PUFAs can modulate EAATs as allosteric modulators and to what extent docosahexaenoic acid (DHA) affects neurotransmission and thereby affects brain functions. Xenopus oocytes have great advantages in the studies about the interactions between molecules and functional proteins, especially in the case when the expression levels of the proteins are small in cell culture systems without transfections. These are also proper to study the mechanisms underlying the interactions. Based on the data collected in Xenopus oocyte experiments, we can proceed to the next step, i.e., the physiological roles of the compounds and their significances. In the case of EAAT2, the effects on the neurotransmission should be examined by electrophysiological approach using acute brain slices. For new drug development, pharmacokinetics pharmacodynamics (PKPD) data and blood brain barrier (BBB) penetration data are also necessary. In order not to miss the promising candidate compounds at the primary stages of drug development, we should reconsider using Xenopus oocytes in the early phase of drug development.
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Grants
- a Research Grant on Regulatory Harmonization and Evaluation of Pharmaceuticals, Medical Devices, Regenerative and Cellular Therapy Products, Gene Therapy Products, and Cosmetics from AMED, Japan Japan Agency for Medical Research and Development
- KAKENHI 18700373, 21700422, 17K08330 Ministry of Education, Culture, Sports, Science and Technology
- a Grant for the Program for Promotion of Fundamental Studies in Health Sciences of NIBIO National Institute of Biomedical Innovation, Health and Nutrition
- a grant for Research on Risks of Chemicals, a Labor Science Research Grant for Research on New Drug Development MHLW
- a Grant-in-Aid from Hoansha Foundation Hoansha Foundation
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Affiliation(s)
| | - Kaoru Sato
- Laboratory of Neuropharmacology, Division of Pharmacology, National Institute of Health Sciences, Kanagawa 210-9501, Japan;
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5
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Benson CA, Olson KL, Patwa S, Kauer SD, King JF, Waxman SG, Tan AM. Conditional Astrocyte Rac1KO Attenuates Hyperreflexia after Spinal Cord Injury. J Neurosci 2024; 44:e1670222023. [PMID: 37963762 PMCID: PMC10851682 DOI: 10.1523/jneurosci.1670-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Revised: 08/24/2023] [Accepted: 09/19/2023] [Indexed: 11/16/2023] Open
Abstract
Spasticity is a hyperexcitability disorder that adversely impacts functional recovery and rehabilitative efforts after spinal cord injury (SCI). The loss of evoked rate-dependent depression (RDD) of the monosynaptic H-reflex is indicative of hyperreflexia, a physiological sign of spasticity. Given the intimate relationship between astrocytes and neurons, that is, the tripartite synapse, we hypothesized that astrocytes might have a significant role in post-injury hyperreflexia and plasticity of neighboring neuronal synaptic dendritic spines. Here, we investigated the effect of selective Rac1KO in astrocytes (i.e., adult male and female mice, transgenic cre-flox system) on SCI-induced spasticity. Three weeks after a mild contusion SCI, control Rac1wt animals displayed a loss of H-reflex RDD, that is, hyperreflexia. In contrast, transgenic animals with astrocytic Rac1KO demonstrated near-normal H-reflex RDD similar to pre-injury levels. Reduced hyperreflexia in astrocytic Rac1KO animals was accompanied by a loss of thin-shaped dendritic spine density on α-motor neurons in the ventral horn. In SCI-Rac1wt animals, as expected, we observed the development of dendritic spine dysgenesis on α-motor neurons associated with spasticity. As compared with WT animals, SCI animals with astrocytic Rac1KO expressed increased levels of the glial-specific glutamate transporter, glutamate transporter-1 in the ventral spinal cord, potentially enhancing glutamate clearance from the synaptic cleft and reducing hyperreflexia in astrocytic Rac1KO animals. Taken together, our findings show for the first time that Rac1 activity in astrocytes can contribute to hyperreflexia underlying spasticity following SCI. These results reveal an opportunity to target cell-specific molecular regulators of H-reflex excitability to manage spasticity after SCI.Significance Statement Spinal cord injury leads to stretch reflex hyperexcitability, which underlies the clinical symptom of spasticity. This study shows for the first time that astrocytic Rac1 contributes to the development of hyperreflexia after SCI. Specifically, astrocytic Rac1KO reduced SCI-related H-reflex hyperexcitability, decreased dendritic spine dysgenesis on α-motor neurons, and elevated the expression of the astrocytic glutamate transporter-1 (GLT-1). Overall, this study supports a distinct role for astrocytic Rac1 signaling within the spinal reflex circuit and the development of SCI-related spasticity.
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Affiliation(s)
- Curtis A Benson
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Kai-Lan Olson
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Siraj Patwa
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Sierra D Kauer
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Jared F King
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Stephen G Waxman
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
| | - Andrew M Tan
- Department of Neurology and Center for Neuroscience and Regeneration Research, Yale University School of Medicine, New Haven, Connecticut 06510,
- Rehabilitation Research Center, Veterans Affairs Connecticut Healthcare System, West Haven, Connecticut 06516
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Popov A, Brazhe N, Morozova K, Yashin K, Bychkov M, Nosova O, Sutyagina O, Brazhe A, Parshina E, Li L, Medyanik I, Korzhevskii DE, Shenkarev Z, Lyukmanova E, Verkhratsky A, Semyanov A. Mitochondrial malfunction and atrophy of astrocytes in the aged human cerebral cortex. Nat Commun 2023; 14:8380. [PMID: 38104196 PMCID: PMC10725430 DOI: 10.1038/s41467-023-44192-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Accepted: 12/04/2023] [Indexed: 12/19/2023] Open
Abstract
How aging affects cells of the human brain active milieu remains largely unknown. Here, we analyze astrocytes and neurons in the neocortical tissue of younger (22-50 years) and older (51-72 years) adults. Aging decreases the amount of reduced mitochondrial cytochromes in astrocytes but not neurons. The protein-to-lipid ratio decreases in astrocytes and increases in neurons. Aged astrocytes show morphological atrophy quantified by the decreased length of branches, decreased volume fraction of leaflets, and shrinkage of the anatomical domain. Atrophy correlates with the loss of gap junction coupling between astrocytes and increased input resistance. Aging is accompanied by the upregulation of glial fibrillary acidic protein (GFAP) and downregulation of membrane-cytoskeleton linker ezrin associated with leaflets. No significant changes in neuronal excitability or spontaneous inhibitory postsynaptic signaling is observed. Thus, brain aging is associated with the impaired morphological presence and mitochondrial malfunction of cortical astrocytes, but not neurons.
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Affiliation(s)
- Alexander Popov
- College of Medicine, Jiaxing University, 314001, Jiaxing, Zhejiang Pro, China
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Nadezda Brazhe
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
- Faculty of Biology, Moscow State University, Moscow, 119234, Russia
| | - Kseniia Morozova
- Faculty of Biology, Moscow State University, Moscow, 119234, Russia
| | - Konstantin Yashin
- Department of Neurosurgery, Privolzhskiy Research Medical University, Nizhny, Novgorod, 603005, Russia
| | - Maxim Bychkov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Olga Nosova
- Institute of Experimental Medicine, St. Petersburg, 197376, Russia
| | - Oksana Sutyagina
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Alexey Brazhe
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
- Faculty of Biology, Moscow State University, Moscow, 119234, Russia
| | - Evgenia Parshina
- Faculty of Biology, Moscow State University, Moscow, 119234, Russia
| | - Li Li
- College of Medicine, Jiaxing University, 314001, Jiaxing, Zhejiang Pro, China
| | - Igor Medyanik
- Department of Neurosurgery, Privolzhskiy Research Medical University, Nizhny, Novgorod, 603005, Russia
| | | | - Zakhar Shenkarev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Ekaterina Lyukmanova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
- Faculty of Biology, Moscow State University, Moscow, 119234, Russia
- Faculty of Biology, Shenzhen MSU-BIT University, 518172, Shenzhen, China
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK.
- Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
- Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain.
| | - Alexey Semyanov
- College of Medicine, Jiaxing University, 314001, Jiaxing, Zhejiang Pro, China.
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia.
- Faculty of Biology, Moscow State University, Moscow, 119234, Russia.
- Sechenov First Moscow State Medical University, Moscow, 119435, Russia.
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7
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LeDuke DO, Borio M, Miranda R, Tye KM. Anxiety and depression: A top-down, bottom-up model of circuit function. Ann N Y Acad Sci 2023; 1525:70-87. [PMID: 37129246 PMCID: PMC10695657 DOI: 10.1111/nyas.14997] [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] [Indexed: 05/03/2023]
Abstract
A functional interplay of bottom-up and top-down processing allows an individual to appropriately respond to the dynamic environment around them. These processing modalities can be represented as attractor states using a dynamical systems model of the brain. The transition probability to move from one attractor state to another is dependent on the stability, depth, neuromodulatory tone, and tonic changes in plasticity. However, how does the relationship between these states change in disease states, such as anxiety or depression? We describe bottom-up and top-down processing from Marr's computational-algorithmic-implementation perspective to understand depressive and anxious disease states. We illustrate examples of bottom-up processing as basolateral amygdala signaling and projections and top-down processing as medial prefrontal cortex internal signaling and projections. Understanding these internal processing dynamics can help us better model the multifaceted elements of anxiety and depression.
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Affiliation(s)
- Deryn O. LeDuke
- Salk Institute for Biological Studies, La Jolla, California, USA
- Biomedical Sciences Graduate Program, University of California San Diego, La Jolla, California, USA
| | - Matilde Borio
- Salk Institute for Biological Studies, La Jolla, California, USA
| | - Raymundo Miranda
- Salk Institute for Biological Studies, La Jolla, California, USA
- Neurosciences Graduate Program, University of California San Diego, La Jolla, California, USA
| | - Kay M. Tye
- Salk Institute for Biological Studies, La Jolla, California, USA
- Howard Hughes Medical Institute, La Jolla, California, USA
- Kavli Institute for the Brain and Mind, La Jolla, California, USA
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8
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Choopani S, Kiani B, Aliakbari S, Babaie J, Golkar M, Pourbadie HG, Sayyah M. Latent toxoplasmosis impairs learning and memory yet strengthens short-term and long-term hippocampal synaptic plasticity at perforant pathway-dentate gyrus, and Schaffer collatterals-CA1 synapses. Sci Rep 2023; 13:8959. [PMID: 37268701 DOI: 10.1038/s41598-023-35971-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Accepted: 05/26/2023] [Indexed: 06/04/2023] Open
Abstract
Investigating long-term potentiation (LTP) in disease models provides essential mechanistic insight into synaptic dysfunction and relevant behavioral changes in many neuropsychiatric and neurological diseases. Toxoplasma (T) gondii is an intracellular parasite causing bizarre changes in host's mind including losing inherent fear of life-threatening situations. We examined hippocampal-dependent behavior as well as in vivo short- and long-term synaptic plasticity (STP and LTP) in rats with latent toxoplasmosis. Rats were infected by T. gondii cysts. Existence of REP-529 genomic sequence of the parasite in the brain was detected by RT-qPCR. Four and eight weeks after infection, spatial, and inhibitory memories of rats were assessed by Morris water maze and shuttle box tests, respectively. Eight weeks after infection, STP was assessed in dentate gyrus (DG) and CA1 by double pulse stimulation of perforant pathway and Shaffer collaterals, respectively. High frequency stimulation (HFS) was applied to induce LTP in entorhinal cortex-DG (400 Hz), and CA3-CA1 (200 Hz) synapses. T. gondii infection retarded spatial learning and memory performance at eight weeks post-infection period, whereas inhibitory memory was not changed. Unlike uninfected rats that normally showed paired-pulse depression, the infected rats developed paired-pulse facilitation, indicating an inhibitory synaptic network disruption. T. gondii-infected rats displayed strengthened LTP of both CA1-pyramidal and DG-granule cell population spikes. These data indicate that T. gondii disrupts inhibition/excitation balance and causes bizarre changes to the post-synaptic neuronal excitability, which may ultimately contribute to the abnormal behavior of the infected host.
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Affiliation(s)
- Samira Choopani
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran
| | - Bahereh Kiani
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran
- Department of Biology, Damghan University, Damghan, Iran
| | - Shayan Aliakbari
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran
| | - Jalal Babaie
- Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran
| | - Majid Golkar
- Department of Parasitology, Pasteur Institute of Iran, Tehran, Iran
| | | | - Mohammad Sayyah
- Department of Physiology and Pharmacology, Pasteur Institute of Iran, Tehran, Iran.
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9
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Schiera G, Cancemi P, Di Liegro CM, Naselli F, Volpes S, Cruciata I, Cardinale PS, Vaglica F, Calligaris M, Carreca AP, Chiarelli R, Scilabra SD, Leone O, Caradonna F, Di Liegro I. An In Vitro Model of Glioma Development. Genes (Basel) 2023; 14:genes14050990. [PMID: 37239349 DOI: 10.3390/genes14050990] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2023] [Revised: 04/20/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
Gliomas are the prevalent forms of brain cancer and derive from glial cells. Among them, astrocytomas are the most frequent. Astrocytes are fundamental for most brain functions, as they contribute to neuronal metabolism and neurotransmission. When they acquire cancer properties, their functions are altered, and, in addition, they start invading the brain parenchyma. Thus, a better knowledge of transformed astrocyte molecular properties is essential. With this aim, we previously developed rat astrocyte clones with increasing cancer properties. In this study, we used proteomic analysis to compare the most transformed clone (A-FC6) with normal primary astrocytes. We found that 154 proteins are downregulated and 101 upregulated in the clone. Moreover, 46 proteins are only expressed in the clone and 82 only in the normal cells. Notably, only 11 upregulated/unique proteins are encoded in the duplicated q arm of isochromosome 8 (i(8q)), which cytogenetically characterizes the clone. Since both normal and transformed brain cells release extracellular vesicles (EVs), which might induce epigenetic modifications in the neighboring cells, we also compared EVs released from transformed and normal astrocytes. Interestingly, we found that the clone releases EVs containing proteins, such as matrix metalloproteinase 3 (MMP3), that can modify the extracellular matrix, thus allowing invasion.
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Affiliation(s)
- Gabriella Schiera
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Edificio 16, 90128 Palermo, Italy
| | - Patrizia Cancemi
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Edificio 16, 90128 Palermo, Italy
| | - Carlo Maria Di Liegro
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Edificio 16, 90128 Palermo, Italy
| | - Flores Naselli
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Edificio 16, 90128 Palermo, Italy
| | - Sara Volpes
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Edificio 16, 90128 Palermo, Italy
| | - Ilenia Cruciata
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Edificio 16, 90128 Palermo, Italy
| | - Paola Sofia Cardinale
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Edificio 16, 90128 Palermo, Italy
| | - Fabiola Vaglica
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Edificio 16, 90128 Palermo, Italy
| | - Matteo Calligaris
- Proteomics Group, Department of Research, ISMETT-IRCCS, Ri.MED Foundation, 90127 Palermo, Italy
| | - Anna Paola Carreca
- Proteomics Group, Department of Research, ISMETT-IRCCS, Ri.MED Foundation, 90127 Palermo, Italy
| | - Roberto Chiarelli
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Edificio 16, 90128 Palermo, Italy
| | - Simone Dario Scilabra
- Proteomics Group, Department of Research, ISMETT-IRCCS, Ri.MED Foundation, 90127 Palermo, Italy
| | - Olga Leone
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palerm, Via del Vespro, 129, 90127 Palermo, Italy
| | - Fabio Caradonna
- Department of Biological, Chemical and Pharmaceutical Sciences and Technologies, University of Palermo, Viale delle Scienze, Edificio 16, 90128 Palermo, Italy
| | - Italia Di Liegro
- Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palerm, Via del Vespro, 129, 90127 Palermo, Italy
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10
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Delepine C, Shih J, Li K, Gaudeaux P, Sur M. Differential Effects of Astrocyte Manipulations on Learned Motor Behavior and Neuronal Ensembles in the Motor Cortex. J Neurosci 2023; 43:2696-2713. [PMID: 36894315 PMCID: PMC10089242 DOI: 10.1523/jneurosci.1982-22.2023] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 01/31/2023] [Accepted: 03/01/2023] [Indexed: 03/11/2023] Open
Abstract
Although motor cortex is crucial for learning precise and reliable movements, whether and how astrocytes contribute to its plasticity and function during motor learning is unknown. Here, we report that astrocyte-specific manipulations in primary motor cortex (M1) during a lever push task alter motor learning and execution, as well as the underlying neuronal population coding. Mice that express decreased levels of the astrocyte glutamate transporter 1 (GLT1) show impaired and variable movement trajectories, whereas mice with increased astrocyte Gq signaling show decreased performance rates, delayed response times, and impaired trajectories. In both groups, which include male and female mice, M1 neurons have altered interneuronal correlations and impaired population representations of task parameters, including response time and movement trajectories. RNA sequencing further supports a role for M1 astrocytes in motor learning and shows changes in astrocytic expression of glutamate transporter genes, GABA transporter genes, and extracellular matrix protein genes in mice that have acquired this learned behavior. Thus, astrocytes coordinate M1 neuronal activity during motor learning, and our results suggest that this contributes to learned movement execution and dexterity through mechanisms that include regulation of neurotransmitter transport and calcium signaling.SIGNIFICANCE STATEMENT We demonstrate for the first time that in the M1 of mice, astrocyte function is critical for coordinating neuronal population activity during motor learning. We demonstrate that knockdown of astrocyte glutamate transporter GLT1 affects specific components of learning, such as smooth trajectory formation. Altering astrocyte calcium signaling by activation of Gq-DREADD upregulates GLT1 and affects other components of learning, such as response rates and reaction times as well as trajectory smoothness. In both manipulations, neuronal activity in motor cortex is dysregulated, but in different ways. Thus, astrocytes have a crucial role in motor learning via their influence on motor cortex neurons, and they do so by mechanisms that include regulation of glutamate transport and calcium signals.
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Affiliation(s)
- Chloe Delepine
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Jennifer Shih
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Keji Li
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Pierre Gaudeaux
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Mriganka Sur
- The Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
- Simons Center for the Social Brain, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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11
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Zakani M, Nigritinou M, Ponleitner M, Takai Y, Hofmann D, Hillebrand S, Höftberger R, Bauer J, Lasztoczi B, Misu T, Kasprian G, Rommer P, Bradl M. Paths to hippocampal damage in neuromyelitis optica spectrum disorders. Neuropathol Appl Neurobiol 2023; 49:e12893. [PMID: 36811295 PMCID: PMC10947283 DOI: 10.1111/nan.12893] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 02/03/2023] [Accepted: 02/14/2023] [Indexed: 02/24/2023]
Abstract
AIMS Many patients with neuromyelitis optica spectrum disorders (NMOSD) suffer from cognitive impairment affecting memory, processing speed and attention and suffer from depressive symptoms. Because some of these manifestations could trace back to the hippocampus, several magnetic resonance imaging (MRI) studies have been performed in the past, with a number of groups describing volume loss of the hippocampus in NMOSD patients, whereas others did not observe such changes. Here, we addressed these discrepancies. METHODS We performed pathological and MRI studies on the hippocampi of NMOSD patients, combined with detailed immunohistochemical analysis of hippocampi from experimental models of NMOSD. RESULTS We identified different pathological scenarios for hippocampal damage in NMOSD and its experimental models. In the first case, the hippocampus was compromised by the initiation of astrocyte injury in this brain region and subsequent local effects of microglial activation and neuronal damage. In the second case, loss of hippocampal volume was seen by MRI in patients with large tissue-destructive lesions in the optic nerves or the spinal cord, and the pathological work-up of tissue derived from a patient with such lesions revealed subsequent retrograde neuronal degeneration affecting different axonal tracts and neuronal networks. It remains to be seen whether remote lesions and associated retrograde neuronal degeneration on their own are sufficient to cause extensive volume loss of the hippocampus, or whether they act in concert with small astrocyte-destructive, microglia-activating lesions in the hippocampus that escape detection by MRI, either due to their small size or due to the chosen time window for examination. CONCLUSIONS Different pathological scenarios can culminate in hippocampal volume loss in NMOSD patients.
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Affiliation(s)
- Mona Zakani
- Division of Neuroimmunology, Center for Brain ResearchMedical University of ViennaViennaAustria
| | - Magdalini Nigritinou
- Division of Neuroimmunology, Center for Brain ResearchMedical University of ViennaViennaAustria
| | | | - Yoshiki Takai
- Department of NeurologyTohoku University Graduate School of MedicineSendaiJapan
| | - Daniel Hofmann
- Division of Neuroimmunology, Center for Brain ResearchMedical University of ViennaViennaAustria
| | - Sophie Hillebrand
- Division of Neuroimmunology, Center for Brain ResearchMedical University of ViennaViennaAustria
| | - Romana Höftberger
- Department of Neurology, Division of Neuropathology and NeurochemistryMedical University of ViennaViennaAustria
| | - Jan Bauer
- Division of Neuroimmunology, Center for Brain ResearchMedical University of ViennaViennaAustria
| | - Balint Lasztoczi
- Division of Cognitive Neurobiology, Center for Brain ResearchMedical University of ViennaViennaAustria
| | - Tatsuro Misu
- Department of NeurologyTohoku University Graduate School of MedicineSendaiJapan
| | - Gregor Kasprian
- Division of Biomedical Imaging and Image‐guided TherapyMedical University of ViennaViennaAustria
| | - Paulus Rommer
- Department of NeurologyMedical University of ViennaViennaAustria
| | - Monika Bradl
- Division of Neuroimmunology, Center for Brain ResearchMedical University of ViennaViennaAustria
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12
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Shen Z, Li ZY, Yu MT, Tan KL, Chen S. Metabolic perspective of astrocyte dysfunction in Alzheimer's disease and type 2 diabetes brains. Biomed Pharmacother 2023; 158:114206. [PMID: 36916433 DOI: 10.1016/j.biopha.2022.114206] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 12/30/2022] [Accepted: 12/30/2022] [Indexed: 01/06/2023] Open
Abstract
The term type III diabetes (T3DM) has been proposed for Alzheimer's disease (AD) due to the shared molecular and cellular features between type 2 diabetes (T2DM) and insulin resistance-associated memory deficits and cognitive decline in elderly individuals. Astrocytes elicit neuroprotective or deleterious effects in AD progression and severity. Patients with T2DM are at a high risk of cognitive impairment, and targeting astrocytes might be promising in alleviating neurodegeneration in the diabetic brain. Recent studies focusing on cell-specific activities in the brain have revealed the important role of astrocytes in brain metabolism (e.g., glucose metabolism, lipid metabolism), neurovascular coupling, synapses, and synaptic plasticity. In this review, we discuss how astrocytes and their dysfunction result in multiple pathological and clinical features of AD and T2DM from a metabolic perspective and the potential comorbid mechanism in these two diseases from the perspective of astrocytes.
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Affiliation(s)
- Zheng Shen
- Zunyi Medical University, Zhuhai Campus, Zhuhai, Guangdong 519041, China
| | - Zheng-Yang Li
- Zunyi Medical University, Zhuhai Campus, Zhuhai, Guangdong 519041, China
| | - Meng-Ting Yu
- Zunyi Medical University, Zhuhai Campus, Zhuhai, Guangdong 519041, China
| | - Kai-Leng Tan
- Institute of Biomedical and Pharmaceutical Sciences, Guangdong University of Technology, Guangzhou, Guangdong 510006, China.
| | - Si Chen
- Zunyi Medical University, Zhuhai Campus, Zhuhai, Guangdong 519041, China.
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13
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Ben-Azu B, Adebayo OG, Jarikre TA, Oyovwi MO, Edje KE, Omogbiya IA, Eduviere AT, Moke EG, Chijioke BS, Odili OS, Omondiabge OP, Oyovbaire A, Esuku DT, Ozah EO, Japhet K. Taurine, an essential β-amino acid insulates against ketamine-induced experimental psychosis by enhancement of cholinergic neurotransmission, inhibition of oxidative/nitrergic imbalances, and suppression of COX-2/iNOS immunoreactions in mice. Metab Brain Dis 2022; 37:2807-2826. [PMID: 36057735 DOI: 10.1007/s11011-022-01075-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 08/23/2022] [Indexed: 12/22/2022]
Abstract
Cholinergic, oxidative, nitrergic alterations, and neuroinflammation are some key neuropathological features common in schizophrenia disease. They involve complex biological processes that alter normal behavior. The present treatments used in the management of the disorder remain ineffective together with some serious side effects as one of their setbacks. Taurine is a naturally occurring essential β-amino acid reported to elicit antipsychotic property in first episode psychosis in clinical setting, thus require preclinical investigation. Hence, we set out to investigate the effects of taurine in the prevention and reversal of ketamine-induced psychotic-like behaviors and the associated putative neurobiological mechanisms underlying its effects. Adult male Swiss mice were sheared into three separate cohorts of experiments (n = 7): drug alone, preventive and reversal studies. Treatments consisted of saline (10 mL/kg/p.o./day), taurine (50 and 100 mg/kg/p.o./day) and risperidone (0.5 mg/kg/p.o./day) with concomitant ketamine (20 mg/kg/i.p./day) injections between days 8-14, or 14 days entirely. Behavioral hyperactivity, despair, cognitive impairment, and catalepsy were measured. Brain oxidative/nitrergic imbalance, immunoreactivity (COX-2 and iNOS), and cholinergic markers were determined in the striatum, prefrontal-cortex, and hippocampus. Taurine abates ketamine-mediated psychotic-like episodes without cataleptogenic potential. Taurine attenuated ketamine-induced decrease in glutathione, superoxide-dismutase and catalase levels in the striatum, prefrontal-cortex and hippocampus. Also, taurine prevented and reversed ketamine-mediated elevation of malondialdehyde, nitrite contents, acetylcholinesterase activity, and suppressed COX-2 and iNOS expressions in a brain-region dependent manner. Conclusively, taurine insulates against ketamine-mediated psychotic phenotype by normalizing brain central cholinergic neurotransmissions, oxidative, nitrergic and suppression of immunoreactive proteins in mice brains.
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Affiliation(s)
- Benneth Ben-Azu
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria.
| | - Olusegun G Adebayo
- Neurophysiology Unit, Department of Physiology, Faculty of Basic Medical Sciences, PAMO University of Medical Sciences, Port-Harcourt, River State, Nigeria
| | - Thiophilus Aghogho Jarikre
- Department of Veterinary Pathology, Faculty of Veterinary Medicine, University of Ibadan, Ibadan, Nigeria
| | - Mega O Oyovwi
- Department of Basic Medical Science, Achievers University, Owo, Ondo State, Nigeria
| | - Kesiena Emmanuel Edje
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Itivere Adrian Omogbiya
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Anthony T Eduviere
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Emuesiri Goodies Moke
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Bienose S Chijioke
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Onyebuchi S Odili
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Osemudiame P Omondiabge
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Aghogho Oyovbaire
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Daniel T Esuku
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Esther O Ozah
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
| | - Kelvin Japhet
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Delta State, Nigeria
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14
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Postnikova TY, Trofimova AM, Zakharova MV, Nosova OI, Brazhe AR, Korzhevskii DE, Semyanov AV, Zaitsev AV. Delayed Impairment of Hippocampal Synaptic Plasticity after Pentylenetetrazole-Induced Seizures in Young Rats. Int J Mol Sci 2022; 23:ijms232113461. [PMID: 36362260 PMCID: PMC9657086 DOI: 10.3390/ijms232113461] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 10/26/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Data on the long-term consequences of a single episode of generalized seizures in infants are inconsistent. In this study, we examined the effects of pentylenetetrazole-induced generalized seizures in three-week-old rats. One month after the seizures, we detected a moderate neuronal loss in several hippocampal regions: CA1, CA3, and hilus, but not in the dentate gyrus. In addition, long-term synaptic potentiation (LTP) was impaired. We also found that the mechanism of plasticity induction was altered: additional activation of metabotropic glutamate receptors (mGluR1) is required for LTP induction in experimental rats. This disturbance of the plasticity induction mechanism is likely due to the greater involvement of perisynaptic NMDA receptors compared to receptors located in the core part of the postsynaptic density. This hypothesis is supported by experiments with selective blockades of core-located NMDA receptors by the use-dependent blocker MK-801. MK-801 had no effect on LTP induction in experimental rats and suppressed LTP in control animals. The weakening of the function of core-located NMDA receptors may be due to the disturbed clearance of glutamate from the synaptic cleft since the distribution of the astrocytic glutamate transporter EAAT2 in experimental animals was found to be altered.
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Affiliation(s)
- Tatyana Y. Postnikova
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia
| | - Alina M. Trofimova
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia
| | - Maria V. Zakharova
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia
| | - Olga I. Nosova
- Institute of Experimental Medicine, Saint Petersburg 197022, Russia
| | - Alexey R. Brazhe
- Faculty of Biology, Moscow State University, Moscow 119234, Russia
| | | | - Alexey V. Semyanov
- Faculty of Biology, Moscow State University, Moscow 119234, Russia
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Moscow 117997, Russia
- Department of Clinical Pharmacology, Sechenov First Moscow State Medical University, Moscow 119435, Russia
| | - Aleksey V. Zaitsev
- Sechenov Institute of Evolutionary Physiology and Biochemistry of RAS, Saint Petersburg 194223, Russia
- Correspondence:
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15
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Popov A, Brazhe N, Fedotova A, Tiaglik A, Bychkov M, Morozova K, Brazhe A, Aronov D, Lyukmanova E, Lazareva N, Li L, Ponimaskin E, Verkhratsky A, Semyanov A. A high-fat diet changes astrocytic metabolism to promote synaptic plasticity and behavior. Acta Physiol (Oxf) 2022; 236:e13847. [PMID: 35653278 DOI: 10.1111/apha.13847] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 05/04/2022] [Accepted: 05/16/2022] [Indexed: 12/28/2022]
Abstract
AIM A high-fat diet (HFD) is generally considered to negatively influence the body, the brain, and cognition. Nonetheless, fat and fatty acids are essential for nourishing and constructing brain tissue. Astrocytes are central for lipolysis and fatty acids metabolism. We tested how HFD affects astrocyte metabolism, morphology, and physiology. METHODS We used Raman microspectroscopy to assess the redox state of mitochondria and lipid content in astrocytes and neurons in hippocampal slices of mice subjected to HFD. Astrocytes were loaded with fluorescent dye through patch pipette for morphological analysis. Whole-cell voltage-clamp recordings were performed to measure transporter and potassium currents. Western blot analysis quantified the expression of astrocyte-specific proteins. Field potential recordings measured the magnitude of long-term potentiation (LTP). Open filed test was performed to evaluate the effect of HFD on animal behavior. RESULTS We found that exposure of young mice to 1 month of HFD increases lipid content and relative amount of reduced cytochromes in astrocytes but not in neurons. Metabolic changes were paralleled with an enlargement of astrocytic territorial domains due to an increased outgrowth of branches and leaflets. Astrocyte remodeling was associated with an increase in expression of ezrin and with no changes in glial fibrillary acidic protein (GFAP), glutamate transporter-1 (GLT-1), and glutamine synthetase (GS). Such physiological (non-reactive) enlargement of astrocytes in the brain active milieu promoted glutamate clearance and LTP and translated into behavioral changes. CONCLUSION Dietary fat intake is not invariably harmful and might exert beneficial effects depending on the biological context.
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Affiliation(s)
- Alexander Popov
- Department of Physiology Jiaxing University College of Medicine Jiaxing China
- Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences Moscow Russia
| | - Nadezda Brazhe
- Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences Moscow Russia
- Faculty of Biology Moscow State University Moscow Russia
| | - Anna Fedotova
- Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences Moscow Russia
- Faculty of Biology Moscow State University Moscow Russia
| | - Alisa Tiaglik
- Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences Moscow Russia
- Faculty of Biology Moscow State University Moscow Russia
| | - Maxim Bychkov
- Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences Moscow Russia
| | | | - Alexey Brazhe
- Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences Moscow Russia
- Faculty of Biology Moscow State University Moscow Russia
| | - Dmitry Aronov
- Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences Moscow Russia
| | - Ekaterina Lyukmanova
- Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences Moscow Russia
- Faculty of Biology Moscow State University Moscow Russia
- Moscow Institute of Physics and Technology (State University) Dolgoprudny Russia
| | | | - Li Li
- Department of Physiology Jiaxing University College of Medicine Jiaxing China
| | | | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health The University of Manchester Manchester UK
- Achucarro Center for Neuroscience IKERBASQUE, Basque Foundation for Science Bilbao Spain
- Department of Neurosciences University of the Basque Country UPV/EHU and CIBERNED Leioa Spain
| | - Alexey Semyanov
- Department of Physiology Jiaxing University College of Medicine Jiaxing China
- Shemyakin‐Ovchinnikov Institute of Bioorganic Chemistry Russian Academy of Sciences Moscow Russia
- Faculty of Biology Moscow State University Moscow Russia
- Sechenov First Moscow State Medical University Moscow Russia
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16
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Tyurikova O, Shih P, Dembitskaya Y, Savtchenko LP, McHugh TJ, Rusakov DA, Semyanov A. K + efflux through postsynaptic NMDA receptors suppresses local astrocytic glutamate uptake. Glia 2022; 70:961-974. [PMID: 35084774 PMCID: PMC9132042 DOI: 10.1002/glia.24150] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 01/14/2022] [Accepted: 01/14/2022] [Indexed: 12/31/2022]
Abstract
Glutamatergic transmission prompts K+ efflux through postsynaptic NMDA receptors. The ensuing hotspot of extracellular K+ elevation depolarizes presynaptic terminal, boosting glutamate release, but whether this also affects glutamate uptake in local astroglia has remained an intriguing question. Here, we find that the pharmacological blockade, or conditional knockout, of postsynaptic NMDA receptors suppresses use-dependent increase in the amplitude and duration of the astrocytic glutamate transporter current (IGluT ), whereas blocking astrocytic K+ channels prevents the duration increase only. Glutamate spot-uncaging reveals that astrocyte depolarization, rather than extracellular K+ rises per se, is required to reduce the amplitude and duration of IGluT . Biophysical simulations confirm that local transient elevations of extracellular K+ can inhibit local glutamate uptake in fine astrocytic processes. Optical glutamate sensor imaging and a two-pathway test relate postsynaptic K+ efflux to enhanced extrasynaptic glutamate signaling. Thus, repetitive glutamatergic transmission triggers a feedback loop in which postsynaptic K+ efflux can transiently facilitate presynaptic release while reducing local glutamate uptake.
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Affiliation(s)
- Olga Tyurikova
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Department of Clinical and Experimental EpilepsyUCL Institute of Neurology, Queen SquareLondonUK
- Brain Science Institute (BSI)RIKENWako‐shiSaitamaJapan
| | - Pei‐Yu Shih
- Brain Science Institute (BSI)RIKENWako‐shiSaitamaJapan
| | - Yulia Dembitskaya
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Brain Science Institute (BSI)RIKENWako‐shiSaitamaJapan
| | - Leonid P. Savtchenko
- Department of Clinical and Experimental EpilepsyUCL Institute of Neurology, Queen SquareLondonUK
| | - Thomas J. McHugh
- Brain Science Institute (BSI)RIKENWako‐shiSaitamaJapan
- RIKEN Center for Brain Science, Wako‐shiSaitamaJapan
| | - Dmitri A. Rusakov
- Department of Clinical and Experimental EpilepsyUCL Institute of Neurology, Queen SquareLondonUK
| | - Alexey Semyanov
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Brain Science Institute (BSI)RIKENWako‐shiSaitamaJapan
- Department of Clinical Pharmacology, Sechenov First Moscow State Medical UniversityMoscowRussia
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17
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Jia K, Frangou P, Karlaftis VM, Ziminski JJ, Giorgio J, Rideaux R, Zamboni E, Hodgson V, Emir U, Kourtzi Z. Neurochemical and functional interactions for improved perceptual decisions through training. J Neurophysiol 2022; 127:900-912. [PMID: 35235415 PMCID: PMC8977131 DOI: 10.1152/jn.00308.2021] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 02/11/2022] [Accepted: 02/28/2022] [Indexed: 11/22/2022] Open
Abstract
Learning and experience are known to improve our ability to make perceptual decisions. Yet, our understanding of the brain mechanisms that support improved perceptual decisions through training remains limited. Here, we test the neurochemical and functional interactions that support learning for perceptual decisions in the context of an orientation identification task. Using magnetic resonance spectroscopy (MRS), we measure neurotransmitters (i.e., glutamate, GABA) that are known to be involved in visual processing and learning in sensory [early visual cortex (EV)] and decision-related [dorsolateral prefrontal cortex (DLPFC)] brain regions. Using resting-state functional magnetic resonance imaging (rs-fMRI), we test for functional interactions between these regions that relate to decision processes. We demonstrate that training improves perceptual judgments (i.e., orientation identification), as indicated by faster rates of evidence accumulation after training. These learning-dependent changes in decision processes relate to lower EV glutamate levels and EV-DLPFC connectivity, suggesting that glutamatergic excitation and functional interactions between visual and dorsolateral prefrontal cortex facilitate perceptual decisions. Further, anodal transcranial direct current stimulation (tDCS) in EV impairs learning, suggesting a direct link between visual cortex excitation and perceptual decisions. Our findings advance our understanding of the role of learning in perceptual decision making, suggesting that glutamatergic excitation for efficient sensory processing and functional interactions between sensory and decision-related regions support improved perceptual decisions.NEW & NOTEWORTHY Combining multimodal brain imaging [magnetic resonance spectroscopy (MRS), functional connectivity] with interventions [transcranial direct current stimulation (tDCS)], we demonstrate that glutamatergic excitation and functional interactions between sensory (visual) and decision-related (dorsolateral prefrontal cortex) areas support our ability to optimize perceptual decisions through training.
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Affiliation(s)
- Ke Jia
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Polytimi Frangou
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Vasilis M Karlaftis
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Joseph J Ziminski
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Joseph Giorgio
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Reuben Rideaux
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Elisa Zamboni
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Victoria Hodgson
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
| | - Uzay Emir
- Purdue University School of Health Sciences, West Lafayette, Indiana
| | - Zoe Kourtzi
- Department of Psychology, University of Cambridge, Cambridge, United Kingdom
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18
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Lopes CR, Amaral IM, Pereira MF, Lopes JP, Madeira D, Canas PM, Cunha RA, Agostinho P. Impact of blunting astrocyte activity on hippocampal synaptic plasticity in a mouse model of early Alzheimer's disease based on amyloid-β peptide exposure. J Neurochem 2022; 160:556-567. [PMID: 35043392 DOI: 10.1111/jnc.15575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/27/2021] [Accepted: 01/12/2022] [Indexed: 11/27/2022]
Abstract
Amyloid-β peptides (Aβ) accumulate in the brain since early Alzheimer's disease (AD) and dysregulate hippocampal synaptic plasticity, the neurophysiological basis of memory. Although the relationship between long-term potentiation (LTP) and memory processes is well established, there is also evidence that long-term depression (LTD) may be crucial for learning and memory. Alterations in synaptic plasticity, namely in LTP, can be due to communication failures between astrocytes and neurons; however, little is known about astrocytes´ ability to control hippocampal LTD, particularly in AD-like conditions. We now aimed to test the involvement of astrocytes in changes of hippocampal LTP and LTD triggered by Aβ1-42 , taking advantage of L-α-aminoadipate (L-AA), a gliotoxin that blunts astrocytic function. The effects of Aβ1-42 exposure was tested in two different experimental paradigms: ex vivo (hippocampal slices superfusion) and in vivo (intracerebroventricular injection), which were previously validated to impair memory and hippocampal synaptic plasticity, two features of early AD. Blunting astrocytic function with L-AA reduced LTP and LTD amplitude in hippocampal slices from control mice but the effect on LTD was less evident, suggesting that astrocytes have a greater influence on LTP than on LTD under non-pathological conditions. However, under AD conditions, blunting astrocytes did not consistently alter the reduction of LTP magnitude and reverted the LTD-to-LTP shift caused by both ex vivo and in vivo Aβ1-42 exposure. This shows that astrocytes were responsible for the hippocampal LTD-to-LTP shift observed in early AD conditions, reinforcing the interest of strategies targeting astrocytes to restore memory and synaptic plasticity deficits present in early AD.
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Affiliation(s)
- Cátia R Lopes
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, FMUC, Portugal
| | - Inês M Amaral
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal
| | | | - João P Lopes
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal
| | - Daniela Madeira
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, FMUC, Portugal
| | - Paula M Canas
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal
| | - Rodrigo A Cunha
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, FMUC, Portugal
| | - Paula Agostinho
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, FMUC, Portugal
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19
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Rapid Regulation of Glutamate Transport: Where Do We Go from Here? Neurochem Res 2022; 47:61-84. [PMID: 33893911 PMCID: PMC8542062 DOI: 10.1007/s11064-021-03329-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Revised: 04/08/2021] [Accepted: 04/13/2021] [Indexed: 01/03/2023]
Abstract
Glutamate is the predominant excitatory neurotransmitter in the mammalian central nervous system (CNS). A family of five Na+-dependent transporters maintain low levels of extracellular glutamate and shape excitatory signaling. Shortly after the research group of the person being honored in this special issue (Dr. Baruch Kanner) cloned one of these transporters, his group and several others showed that their activity can be acutely (within minutes to hours) regulated. Since this time, several different signals and post-translational modifications have been implicated in the regulation of these transporters. In this review, we will provide a brief introduction to the distribution and function of this family of glutamate transporters. This will be followed by a discussion of the signals that rapidly control the activity and/or localization of these transporters, including protein kinase C, ubiquitination, glutamate transporter substrates, nitrosylation, and palmitoylation. We also include the results of our attempts to define the role of palmitoylation in the regulation of GLT-1 in crude synaptosomes. In some cases, the mechanisms have been fairly well-defined, but in others, the mechanisms are not understood. In several cases, contradictory phenomena have been observed by more than one group; we describe these studies with the goal of identifying the opportunities for advancing the field. Abnormal glutamatergic signaling has been implicated in a wide variety of psychiatric and neurologic disorders. Although recent studies have begun to link regulation of glutamate transporters to the pathogenesis of these disorders, it will be difficult to determine how regulation influences signaling or pathophysiology of glutamate without a better understanding of the mechanisms involved.
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20
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Quilgars C, Cazalets JR, Bertrand SS. Developmentally Regulated Modulation of Lumbar Motoneurons by Metabotropic Glutamate Receptors: A Cellular and Behavioral Analysis in Newborn Mice. Front Cell Neurosci 2021; 15:770250. [PMID: 34955751 PMCID: PMC8699010 DOI: 10.3389/fncel.2021.770250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 11/19/2021] [Indexed: 11/18/2022] Open
Abstract
The present study explores the impact of metabotropic glutamate receptor (mGluR) activation on activity-dependent synaptic plasticity (ADSP) and the intrinsic membrane properties of lumbar motoneurons (MNs) using a combination of biochemical, pharmacological, electrophysiological and behavioral techniques. Using spinal cord slices from C57BL/6JRJ mice at two developmental stages, 1-3 and 8-12 postnatal days (P1-P3; P8-P12, respectively), we found that ADSP expressed at glutamatergic synapses between axons conveyed in the ventrolateral funiculus (VLF) and MNs, involved mGluR activation. Using specific agonists of the three groups of mGluRs, we observed that mGluR stimulation causes subtype-specific and developmentally regulated modulation of the ADSP and synaptic transmission at VLF-MN synapses as well as the intrinsic membrane properties of MNs. RT-qPCR analysis revealed a downregulation of mGluR gene expression with age in the ventral part of the lumbar spinal cord. Interestingly, the selective harvest by laser microdissection of MNs innervating the Gastrocnemius and Tibialis anterior muscles unraveled that the level of Grm2 expression is higher in Tibialis MNs compared to Gastrocnemius MNs suggesting a specific mGluR gene expression profile in these two MN pools. Finally, we assessed the functional impact of mGluR modulation on electrically induced bouts of fictive locomotion in the isolated spinal cord preparation of P1-P3 mice, and in vivo during spontaneous episodes of swimming activity in both P1-P3 and P8-P12 mouse pups. We observed that the mGluR agonists induced distinct and specific effects on the motor burst amplitudes and period of the locomotor rhythms tested and that their actions are function of the developmental stage of the animals. Altogether our data show that the metabotropic glutamatergic system exerts a complex neuromodulation in the developing spinal lumbar motor networks and provide new insights into the expression and modulation of ADSP in MNs.
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Affiliation(s)
- Camille Quilgars
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), CNRS UMR 5287, Université de Bordeaux, Bordeaux, France.,Ecole Pratique des Hautes Etudes (EPHE), Paris Sciences et Lettres University, Paris, France
| | - Jean-René Cazalets
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), CNRS UMR 5287, Université de Bordeaux, Bordeaux, France.,Ecole Pratique des Hautes Etudes (EPHE), Paris Sciences et Lettres University, Paris, France
| | - Sandrine S Bertrand
- Institut de Neurosciences Cognitives et Intégratives d'Aquitaine (INCIA), CNRS UMR 5287, Université de Bordeaux, Bordeaux, France.,Ecole Pratique des Hautes Etudes (EPHE), Paris Sciences et Lettres University, Paris, France
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21
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Staurenghi E, Giannelli S, Testa G, Sottero B, Leonarduzzi G, Gamba P. Cholesterol Dysmetabolism in Alzheimer's Disease: A Starring Role for Astrocytes? Antioxidants (Basel) 2021; 10:antiox10121890. [PMID: 34943002 PMCID: PMC8750262 DOI: 10.3390/antiox10121890] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 01/19/2023] Open
Abstract
In recent decades, the impairment of cholesterol metabolism in the pathogenesis of Alzheimer’s disease (AD) has been intensively investigated, and it has been recognized to affect amyloid β (Aβ) production and clearance, tau phosphorylation, neuroinflammation and degeneration. In particular, the key role of cholesterol oxidation products, named oxysterols, has emerged. Brain cholesterol metabolism is independent from that of peripheral tissues and it must be preserved in order to guarantee cerebral functions. Among the cells that help maintain brain cholesterol homeostasis, astrocytes play a starring role since they deliver de novo synthesized cholesterol to neurons. In addition, other physiological roles of astrocytes are to modulate synaptic transmission and plasticity and support neurons providing energy. In the AD brain, astrocytes undergo significant morphological and functional changes that contribute to AD onset and development. However, the extent of this contribution and the role played by oxysterols are still unclear. Here we review the current understanding of the physiological role exerted by astrocytes in the brain and their contribution to AD pathogenesis. In particular, we focus on the impact of cholesterol dysmetabolism on astrocyte functions suggesting new potential approaches to develop therapeutic strategies aimed at counteracting AD development.
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22
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Stachowicz K, Bobula B, Kusek M, Lenda T, Tokarski K. Evidence for the interaction of COX-2 with mGluR5 in the regulation of EAAT1 and EAAT3 protein levels in the mouse hippocampus. The influence of oxidative stress mechanisms. Brain Res 2021; 1771:147660. [PMID: 34529964 DOI: 10.1016/j.brainres.2021.147660] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2021] [Revised: 08/17/2021] [Accepted: 09/07/2021] [Indexed: 12/29/2022]
Abstract
Since we found that inhibition of cyclooxygenase-2 (COX-2) with concomitant application of a metabotropic glutamate receptor subtype 5 (mGluR5) antagonist (MTEP) down-regulates mGluR7 in the hippocampus (HC) and changes behavior of mice, our team decided to investigate the mechanism responsible for the observed changes. The amino acid glutamate (Glu) is a major excitatory neurotransmitter in the brain. Glu uptake is regulated by excitatory amino acid transporters (EAAT). There are five transporters with documented expression in neurons and glia in the central nervous system (CNS). EAATs, maintain the correct transmission of the Glu signal and prevent its toxic accumulation by removing Glu from the synapse. It has been documented that the toxic level of Glu is one of the main causes of mental and cognitive abnormalities. Given the above mechanisms involved in the functioning of the Glu synapse, we hypothesized modification of Glu uptake, involving EAATs as the cause of the observed changes. This study investigated the level of selected EAATs in the HC after chronic treatment with mGluR5 antagonist MTEP, NS398, and their combination using Western blot. Concomitant MTEP treatment with NS398 or a single administration of the above causes changes in LTP and modulation of EAAT levels in mouse HC. As EAATs are cellular markers of oxidative stress mechanisms, the E. coli lipopolysaccharide (LPS) challenge was performed. The modified Barnes maze test (MBM) revealed alterations in the mouse spatial learning abilities. This study reports an interaction between the mGluR5 and COX-2 in the HC, with EAAT1 and EAAT3 involvement.
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Affiliation(s)
- Katarzyna Stachowicz
- Department of Neurobiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland.
| | - Bartosz Bobula
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Magdalena Kusek
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Tomasz Lenda
- Department of Neuro- and Psychopharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
| | - Krzysztof Tokarski
- Department of Physiology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smętna 12, 31-343 Kraków, Poland
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23
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Lalo U, Koh W, Lee CJ, Pankratov Y. The tripartite glutamatergic synapse. Neuropharmacology 2021; 199:108758. [PMID: 34433089 DOI: 10.1016/j.neuropharm.2021.108758] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2021] [Revised: 07/25/2021] [Accepted: 08/20/2021] [Indexed: 12/31/2022]
Abstract
Astroglial cells were long considered as structural and metabolic supporting cells are which do not directly participate in information processing in the brain. Discoveries of responsiveness of astrocytes to synaptically-released glutamate and their capability to release agonists of glutamate receptors awakened extensive studies of glia-neuron communications and led to the revolutionary changes in our understanding of brain cellular networks. Nowadays, astrocytes are widely acknowledged as inseparable element of glutamatergic synapses and role for glutamatergic astrocyte-neuron interactions in the brain computation is emerging. Astroglial glutamate receptors, in particular of NMDA, mGluR3 and mGluR5 types, can activate a variety of molecular cascades leading astroglial-driven modulation of extracellular levels of glutamate and activity of neuronal glutamate receptors. Their preferential location to the astroglial perisynaptic processes facilitates interaction of astrocytes with individual excitatory synapses. Bi-directional glutamatergic communication between astrocytes and neurons underpins a complex, spatially-distributed modulation of synaptic signalling thus contributing to the enrichment of information processing by the neuronal networks. Still, further research is needed to bridge the substantial gaps in our understanding of mechanisms and physiological relevance of astrocyte-neuron glutamatergic interactions, in particular ability of astrocytes directly activate neuronal glutamate receptors by releasing glutamate and, arguably, d-Serine. An emerging roles for aberrant changes in glutamatergic astroglial signalling, both neuroprotective and pathogenic, in neurological and neurodegenerative diseases also require further investigation. This article is part of the special Issue on 'Glutamate Receptors - The Glutamatergic Synapse'.
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Affiliation(s)
- Ulyana Lalo
- School of Life Sciences, Immanuel Kant Baltic Federal University, Kaliningrad, Russia
| | - Wuhyun Koh
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, 34126, South Korea
| | - C Justin Lee
- Center for Cognition and Sociality, Institute for Basic Science, Daejeon, 34126, South Korea
| | - Yuriy Pankratov
- School of Life Sciences, University of Warwick, Coventry, CV4 7AL, United Kingdom.
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24
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Selivanov VA, Zagubnaya OA, Nartsissov YR, Cascante M. Unveiling a key role of oxaloacetate-glutamate interaction in regulation of respiration and ROS generation in nonsynaptic brain mitochondria using a kinetic model. PLoS One 2021; 16:e0255164. [PMID: 34343196 PMCID: PMC8330910 DOI: 10.1371/journal.pone.0255164] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2021] [Accepted: 07/11/2021] [Indexed: 12/21/2022] Open
Abstract
Glutamate plays diverse roles in neuronal cells, affecting cell energetics and reactive oxygen species (ROS) generation. These roles are especially vital for neuronal cells, which deal with high amounts of glutamate as a neurotransmitter. Our analysis explored neuronal glutamate implication in cellular energy metabolism and ROS generation, using a kinetic model that simulates electron transport details in respiratory complexes, linked ROS generation and metabolic reactions. The analysis focused on the fact that glutamate attenuates complex II inhibition by oxaloacetate, stimulating the latter's transformation into aspartate. Such a mechanism of complex II activation by glutamate could cause almost complete reduction of ubiquinone and deficiency of oxidized form (Q), which closes the main stream of electron transport and opens a way to massive ROS generating transfer in complex III from semiquinone radicals to molecular oxygen. In this way, under low workload, glutamate triggers the respiratory chain (RC) into a different steady state characterized by high ROS generation rate. The observed stepwise dependence of ROS generation on glutamate concentration experimentally validated this prediction. However, glutamate's attenuation of oxaloacetate's inhibition accelerates electron transport under high workload. Glutamate-oxaloacetate interaction in complex II regulation underlies the observed effects of uncouplers and inhibitors and acceleration of Ca2+ uptake. Thus, this theoretical analysis uncovered the previously unknown roles of oxaloacetate as a regulator of ROS generation and glutamate as a modifier of this regulation. The model predicted that this mechanism of complex II activation by glutamate might be operative in situ and responsible for excitotoxicity. Spatial-time gradients of synthesized hydrogen peroxide concentration, calculated in the reaction-diffusion model with convection under a non-uniform local approximation of nervous tissue, have shown that overproduction of H2O2 in a cell causes excess of its level in neighbor cells.
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Affiliation(s)
- Vitaly A. Selivanov
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
- CIBER of Hepatic and Digestive Diseases (CIBEREHD) and Metabolomics Node at Spanish National Bioinformatics Institute (INB-ISCIII-ES- ELIXIR), Institute of Health Carlos III (ISCIII), Madrid, Spain
| | - Olga A. Zagubnaya
- Department of Mathematical Modeling and Statistical Analysis, Institute of Cytochemistry and Molecular Pharmacology, Moscow, Russia
| | - Yaroslav R. Nartsissov
- Department of Mathematical Modeling and Statistical Analysis, Institute of Cytochemistry and Molecular Pharmacology, Moscow, Russia
| | - Marta Cascante
- Department of Biochemistry and Molecular Biomedicine, Faculty of Biology, Universitat de Barcelona, Barcelona, Spain
- CIBER of Hepatic and Digestive Diseases (CIBEREHD) and Metabolomics Node at Spanish National Bioinformatics Institute (INB-ISCIII-ES- ELIXIR), Institute of Health Carlos III (ISCIII), Madrid, Spain
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25
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Protective Effect of Memantine on Bergmann Glia and Purkinje Cells Morphology in Optogenetic Model of Neurodegeneration in Mice. Int J Mol Sci 2021; 22:ijms22157822. [PMID: 34360588 PMCID: PMC8346112 DOI: 10.3390/ijms22157822] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 07/15/2021] [Accepted: 07/19/2021] [Indexed: 11/16/2022] Open
Abstract
Spinocerebellar ataxias are a family of fatal inherited diseases affecting the brain. Although specific mutated proteins are different, they may have a common pathogenetic mechanism, such as insufficient glutamate clearance. This function fails in reactive glia, leading to excitotoxicity and overactivation of NMDA receptors. Therefore, NMDA receptor blockers could be considered for the management of excitotoxicity. One such drug, memantine, currently used for the treatment of Alzheimer's disease, could potentially be used for the treatment of other forms of neurodegeneration, for example, spinocerebellar ataxias (SCA). We previously demonstrated close parallels between optogenetically induced cerebellar degeneration and SCA1. Here we induced reactive transformation of cerebellar Bergmann glia (BG) using this novel optogenetic approach and tested whether memantine could counteract changes in BG and Purkinje cell (PC) morphology and expression of the main glial glutamate transporter-excitatory amino acid transporter 1 (EAAT1). Reactive BG induced by chronic optogenetic stimulation presented increased GFAP immunoreactivity, increased thickness and decreased length of its processes. Oral memantine (~90 mg/kg/day for 4 days) prevented thickening of the processes (1.57 to 1.81 vs. 1.62 μm) and strongly antagonized light-induced reduction in their average length (186.0 to 150.8 vs. 171.9 μm). Memantine also prevented the loss of the key glial glutamate transporter EAAT1 on BG. Finally, memantine reduced the loss of PC (4.2 ± 0.2 to 3.2 ± 0.2 vs. 4.1 ± 0.3 cells per 100 μm of the PC layer). These results identify memantine as potential neuroprotective therapeutics for cerebellar ataxias.
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26
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Boender AJ, Bontempi L, Nava L, Pelloux Y, Tonini R. Striatal Astrocytes Shape Behavioral Flexibility via Regulation of the Glutamate Transporter EAAT2. Biol Psychiatry 2021; 89:1045-1057. [PMID: 33516457 DOI: 10.1016/j.biopsych.2020.11.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 10/21/2020] [Accepted: 11/13/2020] [Indexed: 12/31/2022]
Abstract
BACKGROUND Striatal circuits must be modulated for behavioral flexibility, the ability to adapt to environmental changes. Striatal astrocytes contribute to circuit neuromodulation by controlling the activity of ambient neurotransmitters. In particular, extracellular glutamate levels are tightly controlled by the astrocytic glutamate transporter EAAT2, influencing synaptic functioning and neural network activity. However, it remains unclear if EAAT2 responds to environmental cues to specifically shape action control. METHODS To investigate the relationship between behavioral flexibility and experience-dependent regulation of EAAT2 expression in the dorsal striatum, mice were trained on an instrumental task. We manipulated EAAT2 expression using chemogenetic activation of astrocytic Gq signaling or in vivo morpholinos and determined the ability to adapt to novel environmental contingencies. RESULTS The loss of behavioral flexibility with task overtraining is associated with the upregulation of EAAT2, which results in enhanced glutamate clearance and altered modulation of glutamatergic neurotransmission in the lateral part of the dorsal striatum. Interfering with EAAT2 upregulation in this striatal area preserves behavioral flexibility. CONCLUSIONS Astrocytes are emerging as critical regulators of striatal functions. This work demonstrates that plasticity of EAAT2 expression in the lateral part of the dorsal striatum shapes behavior, thus providing novel mechanistic insights into how flexibility in action control is regulated.
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Affiliation(s)
- Arjen J Boender
- Neuromodulation of Cortical and Subcortical Circuits Laboratory, Fondazione Istituto Italiano di Tecnologia, Genova, Italy
| | - Leonardo Bontempi
- Neuromodulation of Cortical and Subcortical Circuits Laboratory, Fondazione Istituto Italiano di Tecnologia, Genova, Italy
| | - Luca Nava
- Neuromodulation of Cortical and Subcortical Circuits Laboratory, Fondazione Istituto Italiano di Tecnologia, Genova, Italy
| | - Yann Pelloux
- Neuromodulation of Cortical and Subcortical Circuits Laboratory, Fondazione Istituto Italiano di Tecnologia, Genova, Italy
| | - Raffaella Tonini
- Neuromodulation of Cortical and Subcortical Circuits Laboratory, Fondazione Istituto Italiano di Tecnologia, Genova, Italy.
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27
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Sancho L, Contreras M, Allen NJ. Glia as sculptors of synaptic plasticity. Neurosci Res 2021; 167:17-29. [PMID: 33316304 PMCID: PMC8513541 DOI: 10.1016/j.neures.2020.11.005] [Citation(s) in RCA: 75] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Revised: 11/05/2020] [Accepted: 11/09/2020] [Indexed: 12/16/2022]
Abstract
Glial cells are non-neuronal cells in the nervous system that are crucial for proper brain development and function. Three major classes of glia in the central nervous system (CNS) include astrocytes, microglia and oligodendrocytes. These cells have dynamic morphological and functional properties and constantly surveil neural activity throughout life, sculpting synaptic plasticity. Astrocytes form part of the tripartite synapse with neurons and perform many homeostatic functions essential to proper synaptic function including clearing neurotransmitter and regulating ion balance; they can modify these properties, in addition to additional mechanisms such as gliotransmitter release, to influence short- and long-term plasticity. Microglia, the resident macrophage of the CNS, monitor synaptic activity and can eliminate synapses by phagocytosis or modify synapses by release of cytokines or neurotrophic factors. Oligodendrocytes regulate speed of action potential conduction and efficiency of information exchange through the formation of myelin, having important consequences for the plasticity of neural circuits. A deeper understanding of how glia modulate synaptic and circuit plasticity will further our understanding of the ongoing changes that take place throughout life in the dynamic environment of the CNS.
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Affiliation(s)
- Laura Sancho
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Minerva Contreras
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA, 92037, USA
| | - Nicola J Allen
- Molecular Neurobiology Laboratory, Salk Institute for Biological Studies, 10010 North Torrey Pines Rd, La Jolla, CA, 92037, USA.
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28
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Rodríguez-Campuzano AG, Ortega A. Glutamate transporters: Critical components of glutamatergic transmission. Neuropharmacology 2021; 192:108602. [PMID: 33991564 DOI: 10.1016/j.neuropharm.2021.108602] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 04/09/2021] [Accepted: 04/27/2021] [Indexed: 02/06/2023]
Abstract
Glutamate is the major excitatory neurotransmitter in the vertebrate central nervous system. Once released, it binds to specific membrane receptors and transporters activating a wide variety of signal transduction cascades, as well as its removal from the synaptic cleft in order to avoid its extracellular accumulation and the overstimulation of extra-synaptic receptors that might result in neuronal death through a process known as excitotoxicity. Although neurodegenerative diseases are heterogenous in clinical phenotypes and genetic etiologies, a fundamental mechanism involved in neuronal degeneration is excitotoxicity. Glutamate homeostasis is critical for brain physiology and Glutamate transporters are key players in maintaining low extracellular Glutamate levels. Therefore, the characterization of Glutamate transporters has been an active area of glutamatergic research for the last 40 years. Transporter activity its regulated at different levels: transcriptional and translational control, transporter protein trafficking and membrane mobility, and through extensive post-translational modifications. The elucidation of these mechanisms has emerged as an important piece to shape our current understanding of glutamate actions in the nervous system.
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Affiliation(s)
- Ada G Rodríguez-Campuzano
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México, 07000, Mexico
| | - Arturo Ortega
- Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado Postal 14-740, Ciudad de México, 07000, Mexico.
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29
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Lockhofen DEL, Mulert C. Neurochemistry of Visual Attention. Front Neurosci 2021; 15:643597. [PMID: 34025339 PMCID: PMC8133366 DOI: 10.3389/fnins.2021.643597] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 04/12/2021] [Indexed: 11/25/2022] Open
Abstract
Visual attention is the cognitive process that mediates the selection of important information from the environment. This selection is usually controlled by bottom-up and top-down attentional biasing. Since for most humans vision is the dominant sense, visual attention is critically important for higher-order cognitive functions and related deficits are a core symptom of many neuropsychiatric and neurological disorders. Here, we summarize the importance and relative contributions of different neuromodulators and neurotransmitters to the neural mechanisms of top-down and bottom-up attentional control. We will not only review the roles of widely accepted neuromodulators, such as acetylcholine, dopamine and noradrenaline, but also the contributions of other modulatory substances. In doing so, we hope to shed some light on the current understanding of the role of neurochemistry in shaping neuron properties contributing to the allocation of attention in the visual field.
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Affiliation(s)
| | - Christoph Mulert
- Center for Psychiatry and Psychotherapy, Justus-Liebig University, Hessen, Germany
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30
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Choi JIV, Tchernookova BK, Kumar W, Kiedrowski L, Goeke C, Guizzetti M, Larson J, Kreitzer MA, Malchow RP. Extracellular ATP-Induced Alterations in Extracellular H + Fluxes From Cultured Cortical and Hippocampal Astrocytes. Front Cell Neurosci 2021; 15:640217. [PMID: 33994945 PMCID: PMC8120152 DOI: 10.3389/fncel.2021.640217] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2020] [Accepted: 03/19/2021] [Indexed: 12/18/2022] Open
Abstract
Small alterations in the level of extracellular H+ can profoundly alter neuronal activity throughout the nervous system. In this study, self-referencing H+-selective microelectrodes were used to examine extracellular H+ fluxes from individual astrocytes. Activation of astrocytes cultured from mouse hippocampus and rat cortex with extracellular ATP produced a pronounced increase in extracellular H+ flux. The ATP-elicited increase in H+ flux appeared to be independent of bicarbonate transport, as ATP increased H+ flux regardless of whether the primary extracellular pH buffer was 26 mM bicarbonate or 1 mM HEPES, and persisted when atmospheric levels of CO2 were replaced by oxygen. Adenosine failed to elicit any change in extracellular H+ fluxes, and ATP-mediated increases in H+ flux were inhibited by the P2 inhibitors suramin and PPADS suggesting direct activation of ATP receptors. Extracellular ATP also induced an intracellular rise in calcium in cultured astrocytes, and ATP-induced rises in both calcium and H+ efflux were significantly attenuated when calcium re-loading into the endoplasmic reticulum was inhibited by thapsigargin. Replacement of extracellular sodium with choline did not significantly reduce the size of the ATP-induced increases in H+ flux, and the increases in H+ flux were not significantly affected by addition of EIPA, suggesting little involvement of Na+/H+ exchangers in ATP-elicited increases in H+ flux. Given the high sensitivity of voltage-sensitive calcium channels on neurons to small changes in levels of free H+, we hypothesize that the ATP-mediated extrusion of H+ from astrocytes may play a key role in regulating signaling at synapses within the nervous system.
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Affiliation(s)
- Ji-In Vivien Choi
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States.,Stritch School of Medicine, Loyola University, Maywood, IL, United States
| | - Boriana K Tchernookova
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States
| | - Wasan Kumar
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States
| | - Lech Kiedrowski
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States.,Spot Cells LLC, Chicago, IL, United States
| | - Calla Goeke
- VA Portland Health Care System, Portland, OR, United States.,Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, United States
| | - Marina Guizzetti
- VA Portland Health Care System, Portland, OR, United States.,Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR, United States
| | - John Larson
- Department of Psychiatry, University of Illinois at Chicago, Chicago, IL, United States
| | - Matthew A Kreitzer
- Department of Biology, Indiana Wesleyan University, Marion, IN, United States
| | - Robert Paul Malchow
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, IL, United States.,Department Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, IL, United States
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31
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Popov A, Brazhe A, Denisov P, Sutyagina O, Li L, Lazareva N, Verkhratsky A, Semyanov A. Astrocyte dystrophy in ageing brain parallels impaired synaptic plasticity. Aging Cell 2021; 20:e13334. [PMID: 33675569 PMCID: PMC7963330 DOI: 10.1111/acel.13334] [Citation(s) in RCA: 67] [Impact Index Per Article: 22.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 12/30/2020] [Accepted: 02/08/2021] [Indexed: 01/02/2023] Open
Abstract
Little is known about age-dependent changes in structure and function of astrocytes and of the impact of these on the cognitive decline in the senescent brain. The prevalent view on the age-dependent increase in reactive astrogliosis and astrocytic hypertrophy requires scrutiny and detailed analysis. Using two-photon microscopy in conjunction with 3D reconstruction, Sholl and volume fraction analysis, we demonstrate a significant reduction in the number and the length of astrocytic processes, in astrocytic territorial domains and in astrocyte-to-astrocyte coupling in the aged brain. Probing physiology of astrocytes with patch clamp, and Ca2+ imaging revealed deficits in K+ and glutamate clearance and spatiotemporal reorganisation of Ca2+ events in old astrocytes. These changes paralleled impaired synaptic long-term potentiation (LTP) in hippocampal CA1 in old mice. Our findings may explain the astroglial mechanisms of age-dependent decline in learning and memory.
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Affiliation(s)
- Alexander Popov
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Institute of NeuroscienceNizhny Novgorod UniversityNizhny NovgorodRussia
| | - Alexey Brazhe
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Faculty of BiologyMoscow State UniversityMoscowRussia
| | - Pavel Denisov
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Institute of NeuroscienceNizhny Novgorod UniversityNizhny NovgorodRussia
| | - Oksana Sutyagina
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Institute of NeuroscienceNizhny Novgorod UniversityNizhny NovgorodRussia
| | - Li Li
- Department of PhysiologyJiaxing University College of MedicineZhejiang ProChina
| | | | - Alexei Verkhratsky
- Sechenov First Moscow State Medical UniversityMoscowRussia
- Faculty of Biology, Medicine and HealthThe University of ManchesterManchesterUK
- Achucarro Center for NeuroscienceIKERBASQUEBasque Foundation for ScienceBilbaoSpain
- Department of NeurosciencesUniversity of the Basque Country UPV/EHU and CIBERNEDLeioaSpain
| | - Alexey Semyanov
- Shemyakin‐Ovchinnikov Institute of Bioorganic ChemistryRussian Academy of SciencesMoscowRussia
- Faculty of BiologyMoscow State UniversityMoscowRussia
- Sechenov First Moscow State Medical UniversityMoscowRussia
- Department of PhysiologyJiaxing University College of MedicineZhejiang ProChina
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Passlick S, Rose CR, Petzold GC, Henneberger C. Disruption of Glutamate Transport and Homeostasis by Acute Metabolic Stress. Front Cell Neurosci 2021; 15:637784. [PMID: 33603647 PMCID: PMC7884476 DOI: 10.3389/fncel.2021.637784] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2020] [Accepted: 01/11/2021] [Indexed: 01/02/2023] Open
Abstract
High-affinity, Na+-dependent glutamate transporters are the primary means by which synaptically released glutamate is removed from the extracellular space. They restrict the spread of glutamate from the synaptic cleft into the perisynaptic space and reduce its spillover to neighboring synapses. Thereby, glutamate uptake increases the spatial precision of synaptic communication. Its dysfunction and the entailing rise of the extracellular glutamate concentration accompanied by an increased spread of glutamate result in a loss of precision and in enhanced excitation, which can eventually lead to neuronal death via excitotoxicity. Efficient glutamate uptake depends on a negative resting membrane potential as well as on the transmembrane gradients of the co-transported ions (Na+, K+, and H+) and thus on the proper functioning of the Na+/K+-ATPase. Consequently, numerous studies have documented the impact of an energy shortage, as occurring for instance during an ischemic stroke, on glutamate clearance and homeostasis. The observations range from rapid changes in the transport activity to altered expression of glutamate transporters. Notably, while astrocytes account for the majority of glutamate uptake under physiological conditions, they may also become a source of extracellular glutamate elevation during metabolic stress. However, the mechanisms of the latter phenomenon are still under debate. Here, we review the recent literature addressing changes of glutamate uptake and homeostasis triggered by acute metabolic stress, i.e., on a timescale of seconds to minutes.
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Affiliation(s)
- Stefan Passlick
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christine R Rose
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Duesseldorf, Duesseldorf, Germany
| | - Gabor C Petzold
- German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Division of Vascular Neurology, University Hospital Bonn, Bonn, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany.,German Center for Neurodegenerative Diseases (DZNE), Bonn, Germany.,Institute of Neurology, University College London, London, United Kingdom
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Li C, Huang L, Jia X, Zhao B, Chen L, Liu Y. Functional glutamate transporters are expressed in the carotid chemoreceptor. Respir Res 2020; 21:208. [PMID: 32771007 PMCID: PMC7414757 DOI: 10.1186/s12931-020-01468-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 07/23/2020] [Indexed: 12/17/2022] Open
Abstract
BACKGROUND The carotid body (CB) plays a critical role in cyclic intermittent hypoxia (CIH)-induced chemosensitivity; however, the underlying mechanism remains uncertain. We have demonstrated the presence of multiple inotropic glutamate receptors (iGluRs) in CB, and that CIH exposure alters the level of some iGluRs in CB. This result implicates glutamatergic signaling in the CB response to hypoxia. The glutamatergic neurotransmission is not only dependent on glutamate and glutamate receptors, but is also dependent on glutamate transporters, including vesicular glutamate transporters (VGluTs) and excitatory amino acid transporters (EAATs). Here, we have further assessed the expression and distribution of VGluTs and EAATs in human and rat CB and the effect of CIH exposure on glutamate transporters expression. METHODS The mRNA of VGluTs and EAATs in the human CB were detected by RT-PCR. The protein expression of VGluTs and EAATs in the human and rat CB were detected by Western blot. The distribution of VGluT3, EAAT2 and EAAT3 were observed by immunohistochemistry staining and immunofluorescence staining. Male Sprague-Dawley (SD) rats were exposed to CIH (FIO2 10-21%, 3 min/3 min for 8 h per day) for 2 weeks. The unpaired Student's t-test was performed. RESULTS Here, we report on the presence of mRNAs for VGluT1-3 and EAAT1-3 in human CB, which is consistent with our previous results in rat CB. The proteins of VGluT1 and 3, EAAT2 and 3, but not VGluT2 and EAAT1, were detected with diverse levels in human and rat CB. Immunostaining showed that VGluT3, the major type of VGluTs in CB, was co-localized with tyrosine hydroxylase (TH) in type I cells. EAAT2 and EAAT3 were distributed not only in type I cells, but also in glial fibrillary acidic protein (GFAP) positive type II cells. Moreover, we found that exposure of SD rats to CIH enhanced the protein level of EAAT3 as well as TH, but attenuated the levels of VGluT3 and EAAT2 in CB. CONCLUSIONS Our study suggests that glutamate transporters are expressed in the CB, and that glutamate transporters may contribute to glutamatergic signaling-dependent carotid chemoreflex to CIH.
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Affiliation(s)
- Chaohong Li
- The First Affiliated Hospital of Xinxiang Medical University, Henan Key Laboratory of Neural Regeneration and Repairment, Henan Neurology Institute, 88 Jiankang Road, Weihui, 453100, Henan, China
| | - Lu Huang
- The First Affiliated Hospital of Xinxiang Medical University, Henan Key Laboratory of Neural Regeneration and Repairment, Henan Neurology Institute, 88 Jiankang Road, Weihui, 453100, Henan, China
| | - Xianglei Jia
- The First Affiliated Hospital of Xinxiang Medical University, Henan Key Laboratory of Neural Regeneration and Repairment, Henan Neurology Institute, 88 Jiankang Road, Weihui, 453100, Henan, China
| | - Baosheng Zhao
- Department of Thoracic Surgery, The First Affiliated Hospital of Xinxiang Medical University, Weihui, Henan, China
| | - Lingyun Chen
- Operating Room, The First Affiliated Hospital of Xinxiang Medical University, Weihui, Henan, China
| | - Yuzhen Liu
- The First Affiliated Hospital of Xinxiang Medical University, Henan Key Laboratory of Neural Regeneration and Repairment, Henan Neurology Institute, 88 Jiankang Road, Weihui, 453100, Henan, China.
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Ponzi A, Barton SJ, Bunner KD, Rangel-Barajas C, Zhang ES, Miller BR, Rebec GV, Kozloski J. Striatal network modeling in Huntington's Disease. PLoS Comput Biol 2020; 16:e1007648. [PMID: 32302302 PMCID: PMC7197869 DOI: 10.1371/journal.pcbi.1007648] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 05/04/2020] [Accepted: 01/09/2020] [Indexed: 12/26/2022] Open
Abstract
Medium spiny neurons (MSNs) comprise over 90% of cells in the striatum. In vivo MSNs display coherent burst firing cell assembly activity patterns, even though isolated MSNs do not burst fire intrinsically. This activity is important for the learning and execution of action sequences and is characteristically dysregulated in Huntington's Disease (HD). However, how dysregulation is caused by the various neural pathologies affecting MSNs in HD is unknown. Previous modeling work using simple cell models has shown that cell assembly activity patterns can emerge as a result of MSN inhibitory network interactions. Here, by directly estimating MSN network model parameters from single unit spiking data, we show that a network composed of much more physiologically detailed MSNs provides an excellent quantitative fit to wild type (WT) mouse spiking data, but only when network parameters are appropriate for the striatum. We find the WT MSN network is situated in a regime close to a transition from stable to strongly fluctuating network dynamics. This regime facilitates the generation of low-dimensional slowly varying coherent activity patterns and confers high sensitivity to variations in cortical driving. By re-estimating the model on HD spiking data we discover network parameter modifications are consistent across three very different types of HD mutant mouse models (YAC128, Q175, R6/2). In striking agreement with the known pathophysiology we find feedforward excitatory drive is reduced in HD compared to WT mice, while recurrent inhibition also shows phenotype dependency. We show that these modifications shift the HD MSN network to a sub-optimal regime where higher dimensional incoherent rapidly fluctuating activity predominates. Our results provide insight into a diverse range of experimental findings in HD, including cognitive and motor symptoms, and may suggest new avenues for treatment.
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Affiliation(s)
- Adam Ponzi
- IBM Research, Computational Biology Center, Thomas J. Watson Research Laboratories, Yorktown Heights, New York, United States of America
- * E-mail:
| | - Scott J. Barton
- Program in Neuroscience, Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - Kendra D. Bunner
- Program in Neuroscience, Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - Claudia Rangel-Barajas
- Program in Neuroscience, Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - Emily S. Zhang
- Program in Neuroscience, Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - Benjamin R. Miller
- Program in Neuroscience, Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - George V. Rebec
- Program in Neuroscience, Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, United States of America
| | - James Kozloski
- IBM Research, Computational Biology Center, Thomas J. Watson Research Laboratories, Yorktown Heights, New York, United States of America
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Popov A, Denisov P, Bychkov M, Brazhe A, Lyukmanova E, Shenkarev Z, Lazareva N, Verkhratsky A, Semyanov A. Caloric restriction triggers morphofunctional remodeling of astrocytes and enhances synaptic plasticity in the mouse hippocampus. Cell Death Dis 2020; 11:208. [PMID: 32231202 PMCID: PMC7105492 DOI: 10.1038/s41419-020-2406-3] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2020] [Revised: 02/15/2020] [Accepted: 02/18/2020] [Indexed: 11/22/2022]
Abstract
Calorie-restricted (CR) diet has multiple beneficial effects on brain function. Here we report morphological and functional changes in hippocampal astrocytes in 3-months-old mice subjected to 1 month of the diet. Whole-cell patch-clamp recordings were performed in the CA1 stratum (str.) radiatum astrocytes of hippocampal slices. The cells were also loaded with fluorescent dye through the patch pipette. CR did not affect the number of astrocytic branches but increased the volume fraction (VF) of distal perisynaptic astrocytic leaflets. The astrocyte growth did not lead to a decrease in the cell input resistance, which may be attributed to a decrease in astrocyte coupling through the gap junctions. Western blotting revealed a decrease in the expression of Cx43 but not Cx30. Immunocytochemical analysis demonstrated a decrease in the density and size of Cx43 clusters. Cx30 cluster density did not change, while their size increased in the vicinity of astrocytic soma. CR shortened K+ and glutamate transporter currents in astrocytes in response to 5 × 50 Hz Schaffer collateral stimulation. However, no change in the expression of astrocytic glutamate transporter 1 (GLT-1) was observed, while the level of glutamine synthetase (GS) decreased. These findings suggest that enhanced enwrapping of synapses by the astrocytic leaflets reduces glutamate and K+ spillover. Reduced spillover led to a decreased contribution of extrasynaptic N2B containing N-methyl-D-aspartate receptors (NMDARs) to the tail of burst-induced EPSCs. The magnitude of long-term potentiation (LTP) in the glutamatergic CA3–CA1 synapses was significantly enhanced after CR. This enhancement was abolished by N2B-NMDARs antagonist. Our findings suggest that astrocytic morphofunctional remodeling is responsible for enhanced synaptic plasticity, which provides a basis for improved learning and memory reported after CR.
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Affiliation(s)
- Alexander Popov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Pavel Denisov
- University of Nizhny Novgorod, Gagarin Ave. 23, Nizhny Novgorod, 603950, Russia
| | - Maxim Bychkov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Alexey Brazhe
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia.,Faculty of Biology, Moscow State University, Leninskie Gory 1/12, Moscow, 119234, Russia
| | - Ekaterina Lyukmanova
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Zakhar Shenkarev
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia
| | - Natalia Lazareva
- Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya, 19с1, Moscow, 119146, Russia
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK. .,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, 48011, Bilbao, Spain.
| | - Alexey Semyanov
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya street 16/10, Moscow, 117997, Russia. .,Faculty of Biology, Moscow State University, Leninskie Gory 1/12, Moscow, 119234, Russia. .,Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya, 19с1, Moscow, 119146, Russia.
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Cell-to-Cell Communication in Learning and Memory: From Neuro- and Glio-Transmission to Information Exchange Mediated by Extracellular Vesicles. Int J Mol Sci 2019; 21:ijms21010266. [PMID: 31906013 PMCID: PMC6982255 DOI: 10.3390/ijms21010266] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 12/14/2019] [Accepted: 12/28/2019] [Indexed: 02/06/2023] Open
Abstract
Most aspects of nervous system development and function rely on the continuous crosstalk between neurons and the variegated universe of non-neuronal cells surrounding them. The most extraordinary property of this cellular community is its ability to undergo adaptive modifications in response to environmental cues originating from inside or outside the body. Such ability, known as neuronal plasticity, allows long-lasting modifications of the strength, composition and efficacy of the connections between neurons, which constitutes the biochemical base for learning and memory. Nerve cells communicate with each other through both wiring (synaptic) and volume transmission of signals. It is by now clear that glial cells, and in particular astrocytes, also play critical roles in both modes by releasing different kinds of molecules (e.g., D-serine secreted by astrocytes). On the other hand, neurons produce factors that can regulate the activity of glial cells, including their ability to release regulatory molecules. In the last fifteen years it has been demonstrated that both neurons and glial cells release extracellular vesicles (EVs) of different kinds, both in physiologic and pathological conditions. Here we discuss the possible involvement of EVs in the events underlying learning and memory, in both physiologic and pathological conditions.
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Verkhratsky A, Rodrigues JJ, Pivoriunas A, Zorec R, Semyanov A. Astroglial atrophy in Alzheimer’s disease. Pflugers Arch 2019; 471:1247-1261. [DOI: 10.1007/s00424-019-02310-2] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 08/23/2019] [Accepted: 09/03/2019] [Indexed: 12/11/2022]
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Stefaniak E, Bal W. Cu II Binding Properties of N-Truncated Aβ Peptides: In Search of Biological Function. Inorg Chem 2019; 58:13561-13577. [PMID: 31304745 DOI: 10.1021/acs.inorgchem.9b01399] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
As life expectancy increases, the number of people affected by progressive and irreversible dementia, Alzheimer's Disease (AD), is predicted to grow. No drug designs seem to be working in humans, apparently because the origins of AD have not been identified. Invoking amyloid cascade, metal ions, and ROS production hypothesis of AD, herein we share our point of view on Cu(II) binding properties of Aβ4-x, the most prevalent N-truncated Aβ peptide, currently known as the main constituent of amyloid plaques. The capability of Aβ4-x to rapidly take over copper from previously tested Aβ1-x peptides and form highly stable complexes, redox unreactive and resistant to copper exchange reactions, prompted us to propose physiological roles for these peptides. We discuss the new findings on the reactivity of Cu(II)Aβ4-x with coexisting biomolecules in the context of synaptic cleft; we suggest that the role of Aβ4-x peptides is to quench Cu(II) toxicity in the brain and maintain neurotransmission.
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Affiliation(s)
- Ewelina Stefaniak
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences , Pawińskiego 5a , 02-106 Warsaw , Poland
| | - Wojciech Bal
- Institute of Biochemistry and Biophysics, Polish Academy of Sciences , Pawińskiego 5a , 02-106 Warsaw , Poland
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