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Ma L, Wu Q, You Y, Zhang P, Tan D, Liang M, Huang Y, Gao Y, Ban Y, Chen Y, Yuan J. Neuronal small extracellular vesicles carrying miR-181c-5p contribute to the pathogenesis of epilepsy by regulating the protein kinase C-δ/glutamate transporter-1 axis in astrocytes. Glia 2024; 72:1082-1095. [PMID: 38385571 DOI: 10.1002/glia.24517] [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: 09/25/2023] [Revised: 01/17/2024] [Accepted: 02/05/2024] [Indexed: 02/23/2024]
Abstract
Information exchange between neurons and astrocytes mediated by extracellular vesicles (EVs) is known to play a key role in the pathogenesis of central nervous system diseases. A key driver of epilepsy is the dysregulation of intersynaptic excitatory neurotransmitters mediated by astrocytes. Thus, we investigated the potential association between neuronal EV microRNAs (miRNAs) and astrocyte glutamate uptake ability in epilepsy. Here, we showed that astrocytes were able to engulf epileptogenic neuronal EVs, inducing a significant increase in the glutamate concentration in the extracellular fluid of astrocytes, which was linked to a decrease in glutamate transporter-1 (GLT-1) protein expression. Using sequencing and gene ontology (GO) functional analysis, miR-181c-5p was found to be the most significantly upregulated miRNA in epileptogenic neuronal EVs and was linked to glutamate metabolism. Moreover, we found that neuronal EV-derived miR-181c-5p interacted with protein kinase C-delta (PKCδ), downregulated PKCδ and GLT-1 protein expression and increased glutamate concentrations in astrocytes both in vitro and in vivo. Our findings demonstrated that epileptogenic neuronal EVs carrying miR-181c-5p decrease the glutamate uptake ability of astrocytes, thus promoting susceptibility to epilepsy.
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Affiliation(s)
- Limin Ma
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
- Department of Neurology, Chongqing University Three Gorges Hospital, Chongqing, China
| | - Qingyuan Wu
- Department of Neurology, Chongqing University Three Gorges Hospital, Chongqing, China
| | - Yu You
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Peng Zhang
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Dandan Tan
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Minxue Liang
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yunyi Huang
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yuan Gao
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yuenan Ban
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Yangmei Chen
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
| | - Jinxian Yuan
- Department of Neurology, The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China
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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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Prasanth MI, Tencomnao T, Brimson JM. The role of the sigma-1 receptor in neuroprotection: Comment on Nrf-2 as a therapeutic target in ischemic stroke. Expert Opin Ther Targets 2021; 25:613-614. [PMID: 34180350 DOI: 10.1080/14728222.2021.1948016] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Accepted: 06/22/2021] [Indexed: 12/18/2022]
Affiliation(s)
- Mani Iyer Prasanth
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - Tewin Tencomnao
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
| | - James Michael Brimson
- Natural Products for Neuroprotection and Anti-ageing Research Unit, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
- Department of Clinical Chemistry, Faculty of Allied Health Sciences, Chulalongkorn University, Bangkok, Thailand
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Ryan RM, Ingram SL, Scimemi A. Regulation of Glutamate, GABA and Dopamine Transporter Uptake, Surface Mobility and Expression. Front Cell Neurosci 2021; 15:670346. [PMID: 33927596 PMCID: PMC8076567 DOI: 10.3389/fncel.2021.670346] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2021] [Accepted: 03/15/2021] [Indexed: 01/31/2023] Open
Abstract
Neurotransmitter transporters limit spillover between synapses and maintain the extracellular neurotransmitter concentration at low yet physiologically meaningful levels. They also exert a key role in providing precursors for neurotransmitter biosynthesis. In many cases, neurons and astrocytes contain a large intracellular pool of transporters that can be redistributed and stabilized in the plasma membrane following activation of different signaling pathways. This means that the uptake capacity of the brain neuropil for different neurotransmitters can be dynamically regulated over the course of minutes, as an indirect consequence of changes in neuronal activity, blood flow, cell-to-cell interactions, etc. Here we discuss recent advances in the mechanisms that control the cell membrane trafficking and biophysical properties of transporters for the excitatory, inhibitory and modulatory neurotransmitters glutamate, GABA, and dopamine.
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Affiliation(s)
- Renae M. Ryan
- School of Medical Sciences, Faculty of Medicine and Health, University of Sydney, Sydney, NSW, Australia
| | - Susan L. Ingram
- Department of Neurological Surgery, Oregon Health & Science University, Portland, OR, United States
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Tao K, Cai Q, Zhang X, Zhu L, Liu Z, Li F, Wang Q, Liu L, Feng D. Astrocytic histone deacetylase 2 facilitates delayed depression and memory impairment after subarachnoid hemorrhage by negatively regulating glutamate transporter-1. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:691. [PMID: 32617311 PMCID: PMC7327310 DOI: 10.21037/atm-20-4330] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Background Delayed cognitive impairment (DCI) after subarachnoid hemorrhage (SAH) is one of the most common sequelae in patients. This study aimed to investigate the characteristics of the course and glutamatergic pathogenesis of DCI after SAH in mice. Methods A SAH mouse model of internal carotid puncture was used. Depressive and cognitive behaviors were detected by forced swimming and sucrose preference tests and Morris water maze test, respectively. Microdialysis and high-performance liquid chromatography (HPLC) were used to detect the interstitial glutamate. The expressions of histone deacetylases (HDACs), glutamate transporters, and glutamate receptors were examined. Primary astrocytes magnetically sorted from adult mice were cultured for glutamate uptake assay and protein and mRNA detection. Selective HDAC2 inhibitor and glutamate transporter-1 (GLT-1) inhibitor administered via were intraperitoneal injection to evaluate their effects on DCI in SAH mice. Results Depression and memory impairment lasted for more than 12 weeks and peaked at 8 weeks after SAH. Interstitial glutamate accumulation in the hippocampus and impaired glutamate uptake in astrocytes of the SAH mice were found during DCI, which could be explained by there being a significant decrease in GLT-1 expression but not in glutamate and aspartate transporter (GLAST) in hippocampal astrocytes. Meanwhile, the phosphorylation level of excitatory glutamate receptors (GluN2B and GluA1) in the hippocampus was significantly reduced, although there was no significant change in the expression of the receptors. Importantly, the expression of HDAC2 increased most significantly in astrocytes after SAH compared with that of other subtypes of HDACs. Inhibition of HDAC2 markedly rescued the decrease in GLT-1 expression after SAH through transcriptional regulation. Behavioral results showed that a selective HDAC2 inhibitor effectively improved DCI in SAH mice, but this effect could be weakened by GLT-1 inhibition. Conclusions In summary, our study suggests that the dysfunction of GLT-1-mediated glutamate uptake in astrocytes may be a key pathological mechanism of DCI after SAH, and that a specific inhibitor of HDAC2 may exert a potential therapy.
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Affiliation(s)
- Kai Tao
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Qing Cai
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Xudong Zhang
- China-Nepal Friendship Medical Research Center of Rajiv Kumar Jha, School of Clinical Medicine, Xi'an Medical University, Xi'an, China
| | - Lin Zhu
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Zhenru Liu
- School of Basic Medicine, Fourth Military Medical University, Xi'an, China
| | - Fei Li
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Qiang Wang
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Lei Liu
- Department of Gastroenterology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
| | - Dayun Feng
- Department of Neurosurgery and Institute for Functional Brain Disorders, Tangdu Hospital, Fourth Military Medical University, Xi'an, China.,School of Basic Medicine, Fourth Military Medical University, Xi'an, China
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Olivares-Bañuelos TN, Chí-Castañeda D, Ortega A. Glutamate transporters: Gene expression regulation and signaling properties. Neuropharmacology 2019; 161:107550. [PMID: 30822498 DOI: 10.1016/j.neuropharm.2019.02.032] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 02/22/2019] [Accepted: 02/24/2019] [Indexed: 12/24/2022]
Abstract
Glutamate is the major excitatory neurotransmitter in the vertebrate central nervous system. During synaptic activity, glutamate is released and binds to specific membrane receptors and transporters activating, in the one hand, a wide variety of signal transduction cascades, while in the other hand, its removal from the synaptic cleft. Extracellular glutamate concentrations are maintained within physiological levels mainly by glia glutamate transporters. Inefficient clearance of this amino acid is neurotoxic due to a prolonged hyperactivation of its postsynaptic receptors, exacerbating a wide array of intracellular events linked to an ionic imbalance, that results in neuronal cell death. This process is known as excitotoxicity and is the underlying mechanisms of an important number of neurodegenerative diseases. Therefore, it is important to understand the regulation of glutamate transporters function. The transporter activity can be regulated at different levels: gene expression, transporter protein targeting and trafficking, and post-translational modifications of the transporter protein. The identification of these mechanisms has paved the way to our current understanding the role of glutamate transporters in brain physiology and will certainly provide the needed biochemical information for the development of therapeutic strategies towards the establishment of novel therapeutic approaches for the treatment and/or prevention of pathologies associated with excitotoxicity insults. This article is part of the issue entitled 'Special Issue on Neurotransmitter Transporters'.
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Affiliation(s)
- Tatiana N Olivares-Bañuelos
- Instituto de Investigaciones Oceanológicas, Universidad Autónoma de Baja California, Carretera Tijuana-Ensenada No. 3917, Fraccionamiento Playitas, 22860, Ensenada, Baja California, Mexico
| | - Donají Chí-Castañeda
- 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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Söderlund J, Lindskog M. Relevance of Rodent Models of Depression in Clinical Practice: Can We Overcome the Obstacles in Translational Neuropsychiatry? Int J Neuropsychopharmacol 2018; 21:668-676. [PMID: 29688411 PMCID: PMC6030948 DOI: 10.1093/ijnp/pyy037] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2017] [Revised: 02/22/2018] [Accepted: 04/13/2018] [Indexed: 12/26/2022] Open
Abstract
The diagnosis of a mental disorder generally depends on clinical observations and phenomenological symptoms reported by the patient. The definition of a given diagnosis is criteria based and relies on the ability to accurately interpret subjective symptoms and complex behavior. This type of diagnosis comprises a challenge to translate to reliable animal models, and these translational uncertainties hamper the development of new treatments. In this review, we will discuss how depressive-like behavior can be induced in rodents, and the relationship between these models and depression in humans. Specifically, we suggest similarities between triggers of depressive-like behavior in animal models and human conditions known to increase the risk of depression, for example exhaustion and bullying. Although we acknowledge the potential problems in comparing animal findings to human conditions, such comparisons are useful for understanding the complexity of depression, and we highlight the need to develop clinical diagnoses and animal models in parallel to overcome translational uncertainties.
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Affiliation(s)
- Johan Söderlund
- Department of Clinical Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Maria Lindskog
- Department of Neurobiology, Care Sciences and Society, Karolinska Institutet, Stockholm, Sweden
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Tolahunase MR, Sagar R, Faiq M, Dada R. Yoga- and meditation-based lifestyle intervention increases neuroplasticity and reduces severity of major depressive disorder: A randomized controlled trial. Restor Neurol Neurosci 2018; 36:423-442. [DOI: 10.3233/rnn-170810] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Madhuri R. Tolahunase
- Department of Anatomy, Lab for Molecular Reproduction and Genetics, All India Institute of Medical Sciences (AIIMS), New Delhi, India
| | - Rajesh Sagar
- Department of Psychiatry, All India Institute of Medical Sciences (AIIMS), New Delhi, India
| | - Muneeb Faiq
- Department of Anatomy, Lab for Molecular Reproduction and Genetics, All India Institute of Medical Sciences (AIIMS), New Delhi, India
| | - Rima Dada
- Department of Anatomy, Lab for Molecular Reproduction and Genetics, All India Institute of Medical Sciences (AIIMS), New Delhi, India
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Dong W, Todd AC, Bröer A, Hulme SR, Bröer S, Billups B. PKC-Mediated Modulation of Astrocyte SNAT3 Glutamine Transporter Function at Synapses in Situ. Int J Mol Sci 2018; 19:ijms19040924. [PMID: 29561757 PMCID: PMC5979592 DOI: 10.3390/ijms19040924] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 03/07/2018] [Accepted: 03/15/2018] [Indexed: 01/13/2023] Open
Abstract
Astrocytes are glial cells that have an intimate physical and functional association with synapses in the brain. One of their main roles is to recycle the neurotransmitters glutamate and gamma-aminobutyric acid (GABA), as a component of the glutamate/GABA-glutamine cycle. They perform this function by sequestering neurotransmitters and releasing glutamine via the neutral amino acid transporter SNAT3. In this way, astrocytes regulate the availability of neurotransmitters and subsequently influence synaptic function. Since many plasma membrane transporters are regulated by protein kinase C (PKC), the aim of this study was to understand how PKC influences SNAT3 glutamine transport in astrocytes located immediately adjacent to synapses. We studied SNAT3 transport by whole-cell patch-clamping and fluorescence pH imaging of single astrocytes in acutely isolated brainstem slices, adjacent to the calyx of the Held synapse. Activation of SNAT3-mediated glutamine transport in these astrocytes was reduced to 77 ± 6% when PKC was activated with phorbol 12-myristate 13-acetate (PMA). This effect was very rapid (within ~20 min) and eliminated by application of bisindolylmaleimide I (Bis I) or 7-hydroxystaurosporine (UCN-01), suggesting that activation of conventional isoforms of PKC reduces SNAT3 function. In addition, cell surface biotinylation experiments in these brain slices show that the amount of SNAT3 in the plasma membrane is reduced by a comparable amount (to 68 ± 5%) upon activation of PKC. This indicates a role for PKC in dynamically controlling the trafficking of SNAT3 transporters in astrocytes in situ. These data demonstrate that PKC rapidly regulates the astrocytic glutamine release mechanism, which would influence the glutamine availability for adjacent synapses and control levels of neurotransmission.
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Affiliation(s)
- Wuxing Dong
- Eccles Institute of Neuroscience, The John Curtin School of Medical Research, The Australian National University, 131 Garran Road, Canberra ACT 2601, Australia.
| | - Alison C Todd
- Eccles Institute of Neuroscience, The John Curtin School of Medical Research, The Australian National University, 131 Garran Road, Canberra ACT 2601, Australia.
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK.
| | - Angelika Bröer
- Research School of Biology, The Australian National University, Linnaeus Way 134, Canberra ACT 2601, Australia.
| | - Sarah R Hulme
- Eccles Institute of Neuroscience, The John Curtin School of Medical Research, The Australian National University, 131 Garran Road, Canberra ACT 2601, Australia.
| | - Stefan Bröer
- Research School of Biology, The Australian National University, Linnaeus Way 134, Canberra ACT 2601, Australia.
| | - Brian Billups
- Eccles Institute of Neuroscience, The John Curtin School of Medical Research, The Australian National University, 131 Garran Road, Canberra ACT 2601, Australia.
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