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Yule DI, Takano T. Pacing intracellular Ca 2+ signals in exocrine acinar cells. J Physiol 2024:10.1113/JP284755. [PMID: 38197224 PMCID: PMC11233423 DOI: 10.1113/jp284755] [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: 12/01/2023] [Accepted: 12/20/2023] [Indexed: 01/11/2024] Open
Abstract
An increase in intracellular [Ca2+ ] in exocrine acinar cells resident in the salivary glands or pancreas is a fundamental event that drives fluid secretion and exocytosis of proteins. Stimulation with secretagogues initiates Ca2+ signals with precise spatiotemporal properties thought to be important for driving physiological output. Both in vitro, in acutely isolated acini, and in vivo, in animals expressing genetically encoded indicators, individual cells appear specialized to initiate Ca2+ signals upon stimulation. Furthermore, these signals appear to spread to neighbouring cells. These properties are present in the absence of a conventional pacemaker mechanism dependent on the cyclical activation of Ca2+ -dependent or Ca2+ -conducting plasma membrane ion channels. In this article, we propose a model for 'pacing' intracellular Ca2+ signals in acinar cells based on the enhanced sensitivity of a subpopulation of individual cells and the intercellular diffusion through gap junctions of inositol 1,4,5-trisphosphate and Ca2+ to neighbouring cells.
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Affiliation(s)
- David I. Yule
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14526. USA
| | - Takahiro Takano
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY 14526. USA
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2
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Abstract
Astrocyte endfeet enwrap the entire vascular tree within the central nervous system, where they perform important functions in regulating the blood-brain barrier (BBB), cerebral blood flow, nutrient uptake, and waste clearance. Accordingly, astrocyte endfeet contain specialized organelles and proteins, including local protein translation machinery and highly organized scaffold proteins, which anchor channels, transporters, receptors, and enzymes critical for astrocyte-vascular interactions. Many neurological diseases are characterized by the loss of polarization of specific endfoot proteins, vascular dysregulation, BBB disruption, altered waste clearance, or, in extreme cases, loss of endfoot coverage. A role for astrocyte endfeet has been demonstrated or postulated in many of these conditions. This review provides an overview of the development, composition, function, and pathological changes of astrocyte endfeet and highlights the gaps in our knowledge that future research should address.
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Affiliation(s)
- Blanca Díaz-Castro
- UK Dementia Research Institute and Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, Scotland, UK;
| | - Stefanie Robel
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA;
| | - Anusha Mishra
- Department of Neurology Jungers Center for Neurosciences Research and Knight Cardiovascular Institute, Oregon Health & Science University, Portland, Oregon, USA;
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Lawrence JM, Schardien K, Wigdahl B, Nonnemacher MR. Roles of neuropathology-associated reactive astrocytes: a systematic review. Acta Neuropathol Commun 2023; 11:42. [PMID: 36915214 PMCID: PMC10009953 DOI: 10.1186/s40478-023-01526-9] [Citation(s) in RCA: 60] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Accepted: 02/08/2023] [Indexed: 03/16/2023] Open
Abstract
In the contexts of aging, injury, or neuroinflammation, activated microglia signaling with TNF-α, IL-1α, and C1q induces a neurotoxic astrocytic phenotype, classified as A1, A1-like, or neuroinflammatory reactive astrocytes. In contrast to typical astrocytes, which promote neuronal survival, support synapses, and maintain blood-brain barrier integrity, these reactive astrocytes downregulate supportive functions and begin to secrete neurotoxic factors, complement components like C3, and chemokines like CXCL10, which may facilitate recruitment of immune cells across the BBB into the CNS. The proportion of pro-inflammatory reactive astrocytes increases with age through associated microglia activation, and these pro-inflammatory reactive astrocytes are particularly abundant in neurodegenerative disorders. As the identification of astrocyte phenotypes progress, their molecular and cellular effects are characterized in a growing array of neuropathologies.
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Affiliation(s)
- Jill M Lawrence
- Molecular and Cell Biology and Genetics Graduate Program, Drexel University College of Medicine, Philadelphia, PA, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Kayla Schardien
- Molecular and Cell Biology and Genetics Graduate Program, Drexel University College of Medicine, Philadelphia, PA, USA
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Brian Wigdahl
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Michael R Nonnemacher
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA.
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA.
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA.
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4
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Sompol P, Gollihue JL, Weiss BE, Lin RL, Case SL, Kraner SD, Weekman EM, Gant JC, Rogers CB, Niedowicz DM, Sudduth TL, Powell DK, Lin AL, Nelson PT, Thibault O, Wilcock DM, Norris CM. Targeting Astrocyte Signaling Alleviates Cerebrovascular and Synaptic Function Deficits in a Diet-Based Mouse Model of Small Cerebral Vessel Disease. J Neurosci 2023; 43:1797-1813. [PMID: 36746627 PMCID: PMC10010459 DOI: 10.1523/jneurosci.1333-22.2023] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 01/25/2023] [Accepted: 01/31/2023] [Indexed: 02/08/2023] Open
Abstract
Despite the indispensable role that astrocytes play in the neurovascular unit, few studies have investigated the functional impact of astrocyte signaling in cognitive decline and dementia related to vascular pathology. Diet-mediated induction of hyperhomocysteinemia (HHcy) recapitulates numerous features of vascular contributions to cognitive impairment and dementia (VCID). Here, we used astrocyte targeting approaches to evaluate astrocyte Ca2+ dysregulation and the impact of aberrant astrocyte signaling on cerebrovascular dysfunction and synapse impairment in male and female HHcy diet mice. Two-photon imaging conducted in fully awake mice revealed activity-dependent Ca2+ dysregulation in barrel cortex astrocytes under HHcy. Stimulation of contralateral whiskers elicited larger Ca2+ transients in individual astrocytes of HHcy diet mice compared with control diet mice. However, evoked Ca2+ signaling across astrocyte networks was impaired in HHcy mice. HHcy also was associated with increased activation of the Ca2+/calcineurin-dependent transcription factor NFAT4, which has been linked previously to the reactive astrocyte phenotype and synapse dysfunction in amyloid and brain injury models. Targeting the NFAT inhibitor VIVIT to astrocytes, using adeno-associated virus vectors, led to reduced GFAP promoter activity in HHcy diet mice and improved functional hyperemia in arterioles and capillaries. VIVIT expression in astrocytes also preserved CA1 synaptic function and improved spontaneous alternation performance on the Y maze. Together, the results demonstrate that aberrant astrocyte signaling can impair the major functional properties of the neurovascular unit (i.e., cerebral vessel regulation and synaptic regulation) and may therefore represent a promising drug target for treating VCID and possibly Alzheimer's disease and other related dementias.SIGNIFICANCE STATEMENT The impact of reactive astrocytes in Alzheimer's disease and related dementias is poorly understood. Here, we evaluated Ca2+ responses and signaling in barrel cortex astrocytes of mice fed with a B-vitamin deficient diet that induces hyperhomocysteinemia (HHcy), cerebral vessel disease, and cognitive decline. Multiphoton imaging in awake mice with HHcy revealed augmented Ca2+ responses in individual astrocytes, but impaired signaling across astrocyte networks. Stimulation-evoked arteriole dilation and elevated red blood cell velocity in capillaries were also impaired in cortex of awake HHcy mice. Astrocyte-specific inhibition of the Ca2+-dependent transcription factor, NFAT, normalized cerebrovascular function in HHcy mice, improved synaptic properties in brain slices, and stabilized cognition. Results suggest that astrocytes are a mechanism and possible therapeutic target for vascular-related dementia.
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Affiliation(s)
- Pradoldej Sompol
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | | | - Blaine E Weiss
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | - Ruei-Lung Lin
- Departments of Pharmacology and Nutritional Sciences
| | - Sami L Case
- Departments of Pharmacology and Nutritional Sciences
| | | | | | - John C Gant
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | | | | | | | | | - Ai-Ling Lin
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | - Peter T Nelson
- Sanders-Brown Center on Aging
- Pathology, University of Kentucky College of Medicine, Lexington, Kentucky 40536
| | - Olivier Thibault
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
| | | | - Christopher M Norris
- Sanders-Brown Center on Aging
- Departments of Pharmacology and Nutritional Sciences
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Zhu L, Liu S, Liao F, Yang J, Liang T, Yang Y, Huang X, Gu L, Su L. Comprehensive Analysis of Blood-Based m6A Methylation in Human Ischemic Stroke. Mol Neurobiol 2023; 60:431-446. [PMID: 36279101 DOI: 10.1007/s12035-022-03064-2] [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: 04/28/2022] [Accepted: 10/03/2022] [Indexed: 01/21/2023]
Abstract
Alterations of N6-methyladenosine (m6A) methylation have been reported in the cerebral cortices of mouse and rat models of ischemic stroke (IS). However, the role of m6A methylation in human IS is still unknown. We assessed m6A levels in peripheral blood from patients with IS and healthy controls. A transient middle cerebral artery occlusion and reperfusion (tMCAO/R) mouse model, and an oxygen-glucose deprivation/reperfusion (OGD/R) model in A172 cells were established to further assess m6A levels. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) and RNA sequencing were performed in the peripheral blood of patients with IS and healthy controls. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes analyses were used to identify underlying biological processes. In this study, we found that global m6A levels were elevated in the peripheral blood of patients with IS, in the cerebral cortex of mice after tMCAO/R treatment and in A172 cells after OGD/R treatment. MeRIP-seq analysis identified 2115 altered m6A peaks in patients with IS, 1052 upregulated and 1063 downregulated. Downregulated methylated mRNAs were enriched in Hippo signaling pathway, cytokine-cytokine receptor interaction, NF-kappa B signaling pathway, etc. Upregulated methylated mRNAs were enriched in calcium signaling pathways, Hedgehog signaling pathway, MAPK signaling pathway, etc. Moreover, a total of 84 differentially expressed mRNAs with altered m6A peaks were identified and enriched in EGFR tyrosine kinase inhibitor, Hematopoietic cell lineage, and cytokine-cytokine receptor interactions. This study is the first to profile the transcriptome-wide m6A methylome of peripheral blood in human IS and uncover increased global m6A levels in the peripheral blood of patients with IS.
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Affiliation(s)
- Lulu Zhu
- School of Public Health, Guangxi Medical University, 22 Shuangyong Road, Nanning, Guangxi, China
| | - Shengying Liu
- School of Public Health, Guangxi Medical University, 22 Shuangyong Road, Nanning, Guangxi, China
| | - Fangping Liao
- School of Public Health, Guangxi Medical University, 22 Shuangyong Road, Nanning, Guangxi, China
| | - Jialei Yang
- School of Public Health, Guangxi Medical University, 22 Shuangyong Road, Nanning, Guangxi, China
| | - Tian Liang
- School of Public Health, Guangxi Medical University, 22 Shuangyong Road, Nanning, Guangxi, China
| | - Yibing Yang
- Department of Internal Neurology, First Affiliated Hospital, Guangxi University of Chinese Medicine, 89-9 Dongge Road, Nanning, Guangxi, China
| | - Xianli Huang
- Department of Internal Neurology, First Affiliated Hospital, Guangxi University of Chinese Medicine, 89-9 Dongge Road, Nanning, Guangxi, China
| | - Lian Gu
- Department of Internal Neurology, First Affiliated Hospital, Guangxi University of Chinese Medicine, 89-9 Dongge Road, Nanning, Guangxi, China.
| | - Li Su
- School of Public Health, Guangxi Medical University, 22 Shuangyong Road, Nanning, Guangxi, China.
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Liang Z, Lou Y, Hao Y, Li H, Feng J, Liu S. The Relationship of Astrocytes and Microglia with Different Stages of Ischemic Stroke. Curr Neuropharmacol 2023; 21:2465-2480. [PMID: 37464832 PMCID: PMC10616922 DOI: 10.2174/1570159x21666230718104634] [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: 11/13/2022] [Revised: 01/31/2023] [Accepted: 02/04/2023] [Indexed: 07/20/2023] Open
Abstract
Ischemic stroke is the predominant cause of severe morbidity and mortality worldwide. Post-stroke neuroinflammation has recently received increasing attention with the aim of providing a new effective treatment strategy for ischemic stroke. Microglia and astrocytes are major components of the innate immune system of the central nervous system. They can be involved in all phases of ischemic stroke, from the early stage, contributing to the first wave of neuronal cell death, to the late stage involving phagocytosis and repair. In the early stage of ischemic stroke, a vicious cycle exists between the activation of microglia and astrocytes (through astrocytic connexin 43 hemichannels), aggravating neuroinflammatory injury post-stroke. However, in the late stage of ischemic stroke, repeatedly activated microglia can induce the formation of glial scars by triggering reactive astrogliosis in the peri-infarct regions, which may limit the movement of activated microglia in reverse and restrict the diffusion of inflammation to healthy brain tissues, alleviating the neuroinflammatory injury poststroke. In this review, we elucidated the various roles of astrocytes and microglia and summarized their relationship with neuroinflammation. We also examined how astrocytes and microglia influence each other at different stages of ischemic stroke. Several potential therapeutic approaches targeting astrocytes and microglia in ischemic stroke have been reviewed. Understanding the details of astrocytemicroglia interaction processes will contribute to a better understanding of the mechanisms underlying ischemic stroke, contributing to the identification of new therapeutic interventions.
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Affiliation(s)
- Zhen Liang
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun, China
| | - Yingyue Lou
- Department of Rehabilitation, The Second Hospital of Jilin University, Changchun, China
| | - Yulei Hao
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Hui Li
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Jiachun Feng
- Department of Neurology and Neuroscience Center, The First Hospital of Jilin University, Changchun, China
| | - Songyan Liu
- Department of Neurology, China-Japan Union Hospital, Jilin University, Changchun, China
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Grienberger C, Giovannucci A, Zeiger W, Portera-Cailliau C. Two-photon calcium imaging of neuronal activity. NATURE REVIEWS. METHODS PRIMERS 2022; 2:67. [PMID: 38124998 PMCID: PMC10732251 DOI: 10.1038/s43586-022-00147-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/07/2022] [Indexed: 12/23/2023]
Abstract
In vivo two-photon calcium imaging (2PCI) is a technique used for recording neuronal activity in the intact brain. It is based on the principle that, when neurons fire action potentials, intracellular calcium levels rise, which can be detected using fluorescent molecules that bind to calcium. This Primer is designed for scientists who are considering embarking on experiments with 2PCI. We provide the reader with a background on the basic concepts behind calcium imaging and on the reasons why 2PCI is an increasingly powerful and versatile technique in neuroscience. The Primer explains the different steps involved in experiments with 2PCI, provides examples of what ideal preparations should look like and explains how data are analysed. We also discuss some of the current limitations of the technique, and the types of solutions to circumvent them. Finally, we conclude by anticipating what the future of 2PCI might look like, emphasizing some of the analysis pipelines that are being developed and international efforts for data sharing.
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Affiliation(s)
- Christine Grienberger
- Department of Biology and Volen National Center for Complex Systems, Brandeis University, Waltham, MA, USA
| | - Andrea Giovannucci
- Joint Department of Biomedical Engineering University of North Carolina at Chapel Hill and North Carolina State University, Chapel Hill, NC, USA
- UNC Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - William Zeiger
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Carlos Portera-Cailliau
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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Sobolczyk M, Boczek T. Astrocytic Calcium and cAMP in Neurodegenerative Diseases. Front Cell Neurosci 2022; 16:889939. [PMID: 35663426 PMCID: PMC9161693 DOI: 10.3389/fncel.2022.889939] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Accepted: 05/05/2022] [Indexed: 12/18/2022] Open
Abstract
It is commonly accepted that the role of astrocytes exceeds far beyond neuronal scaffold and energy supply. Their unique morphological and functional features have recently brough much attention as it became evident that they play a fundamental role in neurotransmission and interact with synapses. Synaptic transmission is a highly orchestrated process, which triggers local and transient elevations in intracellular Ca2+, a phenomenon with specific temporal and spatial properties. Presynaptic activation of Ca2+-dependent adenylyl cyclases represents an important mechanism of synaptic transmission modulation. This involves activation of the cAMP-PKA pathway to regulate neurotransmitter synthesis, release and storage, and to increase neuroprotection. This aspect is of paramount importance for the preservation of neuronal survival and functionality in several pathological states occurring with progressive neuronal loss. Hence, the aim of this review is to discuss mutual relationships between cAMP and Ca2+ signaling and emphasize those alterations at the Ca2+/cAMP crosstalk that have been identified in neurodegenerative disorders, such as Alzheimer's and Parkinson's disease.
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He Y, Hewett SJ. The Cystine/Glutamate Antiporter, System xc– Contributes to Cortical Infarction After Moderate but Not Severe Focal Cerebral Ischemia in Mice. Front Cell Neurosci 2022; 16:821036. [PMID: 35669109 PMCID: PMC9165760 DOI: 10.3389/fncel.2022.821036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Accepted: 04/04/2022] [Indexed: 12/14/2022] Open
Abstract
Understanding the mechanisms underlying ischemic brain injury is of importance to the goal of devising novel therapeutics for protection and/or recovery. Previous work in our laboratory and in others has shown that activation of cystine/glutamate antiporter, system xc– (Sxc–), facilitates neuronal injury in several in vitro models of energy deprivation. However, studies on the contribution of this antiporter to ischemic brain damage in vivo are more limited. Since embolic or thrombotic transient or permanent occlusion of a cerebral blood vessel eventually leads to brain infarction in most stroke cases, we evaluated the contribution of Sxc– to cerebral ischemic damage by comparing brain infarction between mice naturally null for SLC7a11 (SLC7a11sut/sut mice). The gene the encodes for the substrate specific light chain for system xcc– — with their wild type (SLC7a11 + / +)littermates following photothrombotic ischemic stroke of the middle cerebral artery (PTI) and permanent middle cerebral artery occlusion (pMCAo) rendered by cauterization. In the PTI model, we found a time-dependent reduction in cerebral blood flow that reached 50% from baseline in both genotypes 47–48 h post-illumination. Despite this, a remarkable reduction in incidence and total infarct volume of SLC7a11sut/sut mice was revealed 48 h following PTI as compared to SLC7a11+/+ mice. No difference in injury markers and/or infarct volume was measured between genotypes when occlusion of the MCA was permanent, however. Present data demonstrate a model-dependent differential role for Sxc– in focal cerebral ischemic damage, further highlighting that ischemic severity activates heterogeneous biochemical events that lead to damage engendered by stroke.
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Fukuda M, Matsumura T, Suda T, Hirase H. Depth-targeted intracortical microstroke by two-photon photothrombosis in rodent brain. NEUROPHOTONICS 2022; 9:021910. [PMID: 35311215 PMCID: PMC8929553 DOI: 10.1117/1.nph.9.2.021910] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Accepted: 02/24/2022] [Indexed: 05/21/2023]
Abstract
Significance: Photothrombosis is a widely used model of ischemic stroke in rodent experiments. In the photothrombosis model, the photosensitizer rose bengal (RB) is systemically introduced into the blood stream and activated by green light to induce aggregation of platelets that eventually cause vessel occlusion. Since the activation of RB is a one-photon phenomenon and the molecules in the illuminated area (light path) are subject to excitation, targeting of thrombosis is unspecific, especially in the depth dimension. We developed a photothrombosis protocol that can target a single vessel in the cortical parenchyma by two-photon excitation. Aim: We aim to induce a thrombotic stroke in the cortical parenchyma by two-photon activation of RB to confine photothrombosis within a vessel of a target depth. Approach: FITC-dextran is injected into the blood stream to visualize the cerebral blood flow in anesthetized adult mice with a cranial window. After a target vessel is chosen by two-photon imaging (950 nm), RB is injected into the blood stream. The scanning wavelength is changed to 720 nm, and photothrombosis is induced by scanning the target vessel. Results: Two-photon depth-targeted single-vessel photothrombosis was achieved with a success rate of 84.9 % ± 1.7 % and an irradiation duration of < 80 s . Attempts without RB (i.e., only with FITC) did not result in photothrombosis at the excitation wavelength of 720 nm. Conclusions: We described a protocol that achieves depth-targeted single-vessel photothrombosis by two-photon excitation. Simultaneous imaging of blood flow in the targeted vessel using FITC dextran enabled the confirmation of vessel occlusion and prevention of excess irradiation that possibly induces unintended photodamage.
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Affiliation(s)
- Masahiro Fukuda
- Kumamoto University, International Research Center for Medical Sciences, Kumamoto, Japan
- Duke-NUS Medical School, Signature Program in Neuroscience and Behavioral Disorders, Singapore
- Address all correspondence to Masahiro Fukuda, ; Hajime Hirase,
| | - Takayoshi Matsumura
- Jichi Medical University, Division of Inflammation Research, Center for Molecular Medicine, Tochigi, Japan
- National University of Singapore, Cancer Science Institute of Singapore, Singapore
| | - Toshio Suda
- Kumamoto University, International Research Center for Medical Sciences, Kumamoto, Japan
- National University of Singapore, Cancer Science Institute of Singapore, Singapore
| | - Hajime Hirase
- University of Copenhagen, Center for Translational Neuromedicine, Faculty of Health and Life Sciences, Copenhagen, Denmark
- Address all correspondence to Masahiro Fukuda, ; Hajime Hirase,
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Ali M, Tabassum H, Alam MM, Parvez S. N-acetyl-L-cysteine ameliorates mitochondrial dysfunction in ischemia/reperfusion injury via attenuating Drp-1 mediated mitochondrial autophagy. Life Sci 2022; 293:120338. [PMID: 35065167 DOI: 10.1016/j.lfs.2022.120338] [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: 08/29/2021] [Revised: 01/15/2022] [Accepted: 01/16/2022] [Indexed: 10/19/2022]
Abstract
BACKGROUND AND PURPOSE Ischemic reperfusion (I/R) injury causes a wide array of functional and structure alternations of mitochondria, associated with oxidative stress and increased the severity of injury. Despite the previous evidence for N-acetyl-L-cysteine (NAC) provide neuroprotection after I/R injury, it is unknown to evaluate the effect of NAC on altered mitochondrial autophagy forms an essential axis to impaired mitochondrial quality control in cerebral I/R injury. METHODS Male wistar rats subjected to I/R injury were used as transient Middle Cerebral Artery Occlusion (tMCAO) model. After I/R injury, the degree of cerebral tissue injury was detected by infarct volume, H&E staining and behavioral assessment. We also performed mitochondrial reactive oxygen species and mitochondrial membrane potential by flow cytometry and mitochondrial respiratory complexes to evaluate the mitochondrial dysfunction. Finally, we performed the western blotting analysis to measure the apoptotic and autophagic marker. RESULTS We found that NAC administration significantly ameliorates brain injury, improves neurobehavioral outcome, decreases neuroinflammation and mitochondrial mediated oxidative stress. We evaluated the neuroprotective effect of NAC against neuronal apoptosis by assessing its ability to sustained mitochondrial integrity and function. Further studies revealed that beneficial effects of NAC is through targeting the mitochondrial autophagy via regulating the GSK-3β/Drp1mediated mitochondrial fission and inhibiting the expression of beclin-1 and conversion of LC3, as well as activating the p-Akt pro-survival pathway. CONCLUSION Our results suggest that NAC exerts neuroprotective effects to inhibit the altered mitochondrial changes and cell death in I/R injury via regulation of p-GSK-3β mediated Drp-1 translocation to the mitochondria.
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Affiliation(s)
- Mubashshir Ali
- Department of Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India
| | - Heena Tabassum
- Division of Basic Medical Sciences, Indian Council of Medical Research, Government of India, V. Ramalingaswamy Bhawan, New Delhi 110029, India
| | - M Mumtaz Alam
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Jamia Hamdard, New Delhi 110062, India
| | - Suhel Parvez
- Department of Toxicology, School of Chemical and Life Sciences, Jamia Hamdard, New Delhi 110062, India.
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Singer T, Ding S, Ding S. Astroglia Abnormalities in Post-stroke Mood Disorders. ADVANCES IN NEUROBIOLOGY 2021; 26:115-138. [PMID: 34888833 DOI: 10.1007/978-3-030-77375-5_6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Stroke is the leading cause of human death and disability. After a stroke, many patients may have some physical disability, including difficulties in moving, speaking, and seeing, but patients may also exhibit changes in mood manifested by depression, anxiety, and cognitive changes which we call post-stroke mood disorders (PSMDs). Astrocytes are the most diverse and numerous glial cell type in the central nervous system (CNS). They provide structural, nutritional, and metabolic support to neurons and regulate synaptic activity under normal conditions. Astrocytes are also critically involved in focal ischemic stroke (FIS). They undergo many changes after FIS. These changes may affect acute neuronal death and brain damage as well as brain recovery and PSMD in the chronic phase after FIS. Studies using postmortem brain specimens and animal models of FIS suggest that astrocytes/reactive astrocytes are involved in PSMD. This chapter provides an overview of recent advances in the molecular base of astrocyte in PSMD. As astrocytes exhibit high plasticity after FIS, we suggest that targeting local astrocytes may be a promising strategy for PSMD therapy.
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Affiliation(s)
- Tracey Singer
- Dalton Cardiovascular Research Center, Columbia, MO, USA
| | - Sarah Ding
- Dalton Cardiovascular Research Center, Columbia, MO, USA
| | - Shinghua Ding
- Dalton Cardiovascular Research Center, Columbia, MO, USA.
- Department of Biomedical, Biological and Chemical Engineering, University of Missouri, Columbia, MO, USA.
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13
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Alia C, Cangi D, Massa V, Salluzzo M, Vignozzi L, Caleo M, Spalletti C. Cell-to-Cell Interactions Mediating Functional Recovery after Stroke. Cells 2021; 10:3050. [PMID: 34831273 PMCID: PMC8623942 DOI: 10.3390/cells10113050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 10/27/2021] [Accepted: 11/02/2021] [Indexed: 12/22/2022] Open
Abstract
Ischemic damage in brain tissue triggers a cascade of molecular and structural plastic changes, thus influencing a wide range of cell-to-cell interactions. Understanding and manipulating this scenario of intercellular connections is the Holy Grail for post-stroke neurorehabilitation. Here, we discuss the main findings in the literature related to post-stroke alterations in cell-to-cell interactions, which may be either detrimental or supportive for functional recovery. We consider both neural and non-neural cells, starting from astrocytes and reactive astrogliosis and moving to the roles of the oligodendrocytes in the support of vulnerable neurons and sprouting inhibition. We discuss the controversial role of microglia in neural inflammation after injury and we conclude with the description of post-stroke alterations in pyramidal and GABAergic cells interactions. For all of these sections, we review not only the spontaneous evolution in cellular interactions after ischemic injury, but also the experimental strategies which have targeted these interactions and that are inspiring novel therapeutic strategies for clinical application.
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Affiliation(s)
- Claudia Alia
- Neuroscience Institute, National Research Council (CNR), Via G. Moruzzi 1, 56124 Pisa, Italy; (V.M.); (M.S.); (M.C.); (C.S.)
| | - Daniele Cangi
- Department of Neurosciences, Psychology, Drugs and Child Health Area, School of Psychology, University of Florence, 50121 Florence, Italy;
| | - Verediana Massa
- Neuroscience Institute, National Research Council (CNR), Via G. Moruzzi 1, 56124 Pisa, Italy; (V.M.); (M.S.); (M.C.); (C.S.)
| | - Marco Salluzzo
- Neuroscience Institute, National Research Council (CNR), Via G. Moruzzi 1, 56124 Pisa, Italy; (V.M.); (M.S.); (M.C.); (C.S.)
- Department of Neurosciences, Psychology, Drugs and Child Health Area, School of Psychology, University of Florence, 50121 Florence, Italy;
| | - Livia Vignozzi
- Department of Biomedical Sciences, University of Padua, Viale G. Colombo 3, 35121 Padua, Italy;
| | - Matteo Caleo
- Neuroscience Institute, National Research Council (CNR), Via G. Moruzzi 1, 56124 Pisa, Italy; (V.M.); (M.S.); (M.C.); (C.S.)
- Department of Biomedical Sciences, University of Padua, Viale G. Colombo 3, 35121 Padua, Italy;
| | - Cristina Spalletti
- Neuroscience Institute, National Research Council (CNR), Via G. Moruzzi 1, 56124 Pisa, Italy; (V.M.); (M.S.); (M.C.); (C.S.)
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14
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Moulson AJ, Squair JW, Franklin RJM, Tetzlaff W, Assinck P. Diversity of Reactive Astrogliosis in CNS Pathology: Heterogeneity or Plasticity? Front Cell Neurosci 2021; 15:703810. [PMID: 34381334 PMCID: PMC8349991 DOI: 10.3389/fncel.2021.703810] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Accepted: 07/02/2021] [Indexed: 01/02/2023] Open
Abstract
Astrocytes are essential for the development and homeostatic maintenance of the central nervous system (CNS). They are also critical players in the CNS injury response during which they undergo a process referred to as "reactive astrogliosis." Diversity in astrocyte morphology and gene expression, as revealed by transcriptional analysis, is well-recognized and has been reported in several CNS pathologies, including ischemic stroke, CNS demyelination, and traumatic injury. This diversity appears unique to the specific pathology, with significant variance across temporal, topographical, age, and sex-specific variables. Despite this, there is limited functional data corroborating this diversity. Furthermore, as reactive astrocytes display significant environmental-dependent plasticity and fate-mapping data on astrocyte subsets in the adult CNS is limited, it remains unclear whether this diversity represents heterogeneity or plasticity. As astrocytes are important for neuronal survival and CNS function post-injury, establishing to what extent this diversity reflects distinct established heterogeneous astrocyte subpopulations vs. environmentally dependent plasticity within established astrocyte subsets will be critical for guiding therapeutic development. To that end, we review the current state of knowledge on astrocyte diversity in the context of three representative CNS pathologies: ischemic stroke, demyelination, and traumatic injury, with the goal of identifying key limitations in our current knowledge and suggesting future areas of research needed to address them. We suggest that the majority of identified astrocyte diversity in CNS pathologies to date represents plasticity in response to dynamically changing post-injury environments as opposed to heterogeneity, an important consideration for the understanding of disease pathogenesis and the development of therapeutic interventions.
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Affiliation(s)
- Aaron J. Moulson
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
- International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada
| | - Jordan W. Squair
- Department of Clinical Neuroscience, Faculty of Life Sciences, Center for Neuroprosthetics and Brain Mind Institute, École Polytechnique Fédérale de Lausanne (EPFL), NeuroRestore, Lausanne University Hospital (CHUV), University of Lausanne (UNIL), Lausanne, Switzerland
| | - Robin J. M. Franklin
- Wellcome Trust - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
| | - Wolfram Tetzlaff
- International Collaboration on Repair Discoveries (ICORD), Vancouver, BC, Canada
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada
- Department of Surgery, University of British Columbia, Vancouver, BC, Canada
| | - Peggy Assinck
- Wellcome Trust - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, United Kingdom
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, University of Edinburgh, Edinburgh, United Kingdom
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15
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Saito K, Shigetomi E, Koizumi S. [Alexander disease: diversity of cell population and interactions between neuron and glia]. Nihon Yakurigaku Zasshi 2021; 156:239-243. [PMID: 34193704 DOI: 10.1254/fpj.21028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Alexander disease (AxD) is a rare neurodegenerative disorder caused by the mutations in glial fibrillary acidic protein (GFAP) gene. Rosenthal fiber formations in astrocytes are the pathological hallmarks of AxD. Astrocyte dysfunction in the AxD brain is considered to be involved in its pathogenesis. We have previously reported that in AxD model mice aberrant Ca2+ signals in astrocytes were associated with the upregulation of reactive phenotype. Reactive astrocytes are conditions that lead to morphological, functional, and molecular changes by responding to various pathological insults (trauma, inflammation, ischemia), and environmental stimuli. Recent technological advances in single-cell gene expression analysis have revealed that astrocytes have heterogeneity by indicating that they form sub population with different characteristics depending on the brain region, the growth development, aging stage, and the pathological condition. AxD astrocytes are also thought to constitute a heterogeneous population with diverse properties and functions. Moreover, it is presumed that AxD pathogenesis occur due to interactions with neurons and other glial cells, as well as the microenvironment in tissues. Research strategies based on these perspectives will help us understand AxD pathology better and may lead to the elucidation of disease modifiers and clinical diversity.
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Affiliation(s)
- Kozo Saito
- Department of Neuropharmcology, Interdisciplinary Graduate School of Medicine
| | - Eiji Shigetomi
- Department of Neuropharmcology, Interdisciplinary Graduate School of Medicine
| | - Schuichi Koizumi
- Department of Neuropharmcology, Interdisciplinary Graduate School of Medicine
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16
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Honoré E, Khlaifia A, Bosson A, Lacaille JC. Hippocampal Somatostatin Interneurons, Long-Term Synaptic Plasticity and Memory. Front Neural Circuits 2021; 15:687558. [PMID: 34149368 PMCID: PMC8206813 DOI: 10.3389/fncir.2021.687558] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2021] [Accepted: 04/30/2021] [Indexed: 12/13/2022] Open
Abstract
A distinctive feature of the hippocampal structure is the diversity of inhibitory interneurons. These complex inhibitory interconnections largely contribute to the tight modulation of hippocampal circuitry, as well as to the formation and coordination of neuronal assemblies underlying learning and memory. Inhibitory interneurons provide more than a simple transitory inhibition of hippocampal principal cells (PCs). The synaptic plasticity of inhibitory neurons provides long-lasting changes in the hippocampal network and is a key component of memory formation. The dendrite targeting interneurons expressing the peptide somatostatin (SOM) are particularly interesting in this regard because they display unique long-lasting synaptic changes leading to metaplastic regulation of hippocampal networks. In this article, we examine the actions of the neuropeptide SOM on hippocampal cells, synaptic plasticity, learning, and memory. We address the different subtypes of hippocampal SOM interneurons. We describe the long-term synaptic plasticity that takes place at the excitatory synapses of SOM interneurons, its singular induction and expression mechanisms, as well as the consequences of these changes on the hippocampal network, learning, and memory. We also review evidence that astrocytes provide cell-specific dynamic regulation of inhibition of PC dendrites by SOM interneurons. Finally, we cover how, in mouse models of Alzheimer’s disease (AD), dysfunction of plasticity of SOM interneuron excitatory synapses may also contribute to cognitive impairments in brain disorders.
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Affiliation(s)
- Eve Honoré
- Department of Neurosciences, Centre for Interdisciplinary Research on Brain and Learning, Research Group on the Central Nervous System, Université de Montréal, Montreal, QC, Canada
| | - Abdessattar Khlaifia
- Department of Neurosciences, Centre for Interdisciplinary Research on Brain and Learning, Research Group on the Central Nervous System, Université de Montréal, Montreal, QC, Canada
| | - Anthony Bosson
- Department of Neurosciences, Centre for Interdisciplinary Research on Brain and Learning, Research Group on the Central Nervous System, Université de Montréal, Montreal, QC, Canada
| | - Jean-Claude Lacaille
- Department of Neurosciences, Centre for Interdisciplinary Research on Brain and Learning, Research Group on the Central Nervous System, Université de Montréal, Montreal, QC, Canada
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17
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Adrenergic inhibition facilitates normalization of extracellular potassium after cortical spreading depolarization. Sci Rep 2021; 11:8150. [PMID: 33854148 PMCID: PMC8047013 DOI: 10.1038/s41598-021-87609-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Accepted: 03/31/2021] [Indexed: 01/31/2023] Open
Abstract
Cortical spreading depolarization (CSD) is a propagating wave of tissue depolarization characterized by a large increase of extracellular potassium concentration and prolonged subsequent electrical silencing of neurons. Waves of CSD arise spontaneously in various acute neurological settings, including migraine aura and ischemic stroke. Recently, we have reported that pan-inhibition of adrenergic receptors (AdRs) facilitates the normalization of extracellular potassium after acute photothrombotic stroke in mice. Here, we have extended that mechanistic study to ask whether AdR antagonists also modify the dynamics of KCl-induced CSD and post-CSD recovery in vivo. Spontaneous neural activity and KCl-induced CSD were visualized by cortex-wide transcranial Ca2+ imaging in G-CaMP7 transgenic mice. AdR antagonism decreased the recurrence of CSD waves and accelerated the post-CSD recovery of neural activity. Two-photon imaging revealed that astrocytes exhibited aberrant Ca2+ signaling after passage of the CSD wave. This astrocytic Ca2+ activity was diminished by the AdR antagonists. Furthermore, AdR pan-antagonism facilitated the normalization of the extracellular potassium level after CSD, which paralleled the recovery of neural activity. These observations add support to the proposal that neuroprotective effects of AdR pan-antagonism arise from accelerated normalization of extracellular K+ levels in the setting of acute brain injury.
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18
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Ca 2+ homeostasis in brain microvascular endothelial cells. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 362:55-110. [PMID: 34253298 DOI: 10.1016/bs.ircmb.2021.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Blood brain barrier (BBB) is formed by the brain microvascular endothelial cells (BMVECs) lining the wall of brain capillaries. Its integrity is regulated by multiple mechanisms, including up/downregulation of tight junction proteins or adhesion molecules, altered Ca2+ homeostasis, remodeling of cytoskeleton, that are confined at the level of BMVECs. Beside the contribution of BMVECs to BBB permeability changes, other cells, such as pericytes, astrocytes, microglia, leukocytes or neurons, etc. are also exerting direct or indirect modulatory effects on BBB. Alterations in BBB integrity play a key role in multiple brain pathologies, including neurological (e.g. epilepsy) and neurodegenerative disorders (e.g. Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis etc.). In this review, the principal Ca2+ signaling pathways in brain microvascular endothelial cells are discussed and their contribution to BBB integrity is emphasized. Improving the knowledge of Ca2+ homeostasis alterations in BMVECa is fundamental to identify new possible drug targets that diminish/prevent BBB permeabilization in neurological and neurodegenerative disorders.
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19
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Ma Q, Feng L, Wang T, Li Y, Li Z, Zhao B, Qin X, Li Q, Wu S, Sun H, Yuan J, Chu L, Wu J, Gu Y, Pang P, Chen Z, Fan D. 2020 expert consensus statement on neuro-protection after cardiac arrest in China. ANNALS OF TRANSLATIONAL MEDICINE 2021; 9:175. [PMID: 33569477 PMCID: PMC7867902 DOI: 10.21037/atm-20-7853] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Affiliation(s)
- Qingbian Ma
- Emergency Department, Peking University Third Hospital, Beijing, China
| | - Liqun Feng
- Neurology Department, Anzhen Hospital, Capital Medical University, Beijing, China
| | - Tao Wang
- Neurosurgery Department, Peking University Third Hospital, Beijing, China
| | - Yongqiu Li
- Neurology Department, Tangshan Gongren Hospital, Tangshan, China
| | - Zhenzhong Li
- Neurology Department, The Second Hospital of Hebei Medical University, Shijiazhuang, China
| | - Bin Zhao
- Emergency Department, Beijing Jishuitan Hospital, Beijing, China
| | - Xiuchuan Qin
- Emergency Department, Anzhen Hospital, Capital Medical University, Beijing, China
| | - Qingxi Li
- Neurosurgery Department, Dandong Central Hospital, Dandong, China
| | - Shizheng Wu
- Neurology Department, Qinghai Provincial People's Hospital, Xining, China
| | - Hongbin Sun
- Neurology Department, Sichuan Provincial People's Hospital, Chengdu, China
| | - Jun Yuan
- Neurology Department, Inner Mongolia People's Hospital, Hohhot, China
| | - Lan Chu
- Neurology Department, The Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Jian Wu
- Neurology Department, Beijing Tsinghua Changgung Hospital, Beijing, China
| | - Yuxiang Gu
- Neurosurgery Department, Fudan University Huashan Hospital, Shanghai, China
| | - Peter Pang
- Accident and Emergency Department, Yan Chai Hospital, Hong Kong, China
| | - Zhi Chen
- Beijing Emergency Medical Center, Beijing, China
| | - Dongsheng Fan
- Neurology Department, Peking University Third Hospital, Beijing, China
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20
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Presa JL, Saravia F, Bagi Z, Filosa JA. Vasculo-Neuronal Coupling and Neurovascular Coupling at the Neurovascular Unit: Impact of Hypertension. Front Physiol 2020; 11:584135. [PMID: 33101063 PMCID: PMC7546852 DOI: 10.3389/fphys.2020.584135] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/04/2020] [Indexed: 12/18/2022] Open
Abstract
Components of the neurovascular unit (NVU) establish dynamic crosstalk that regulates cerebral blood flow and maintain brain homeostasis. Here, we describe accumulating evidence for cellular elements of the NVU contributing to critical physiological processes such as cerebral autoregulation, neurovascular coupling, and vasculo-neuronal coupling. We discuss how alterations in the cellular mechanisms governing NVU homeostasis can lead to pathological changes in which vascular endothelial and smooth muscle cell, pericyte and astrocyte function may play a key role. Because hypertension is a modifiable risk factor for stroke and accelerated cognitive decline in aging, we focus on hypertension-associated changes on cerebral arteriole function and structure, and the molecular mechanisms through which these may contribute to cognitive decline. We gather recent emerging evidence concerning cognitive loss in hypertension and the link with vascular dementia and Alzheimer’s disease. Collectively, we summarize how vascular dysfunction, chronic hypoperfusion, oxidative stress, and inflammatory processes can uncouple communication at the NVU impairing cerebral perfusion and contributing to neurodegeneration.
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Affiliation(s)
- Jessica L Presa
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States.,Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - Flavia Saravia
- Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and Instituto de Biología y Medicina Experimental, CONICET, Buenos Aires, Argentina
| | - Zsolt Bagi
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States
| | - Jessica A Filosa
- Department of Physiology, Medical College of Georgia, Augusta University, Augusta, GA, United States
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21
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Li X, Li M, Tian L, Chen J, Liu R, Ning B. Reactive Astrogliosis: Implications in Spinal Cord Injury Progression and Therapy. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:9494352. [PMID: 32884625 PMCID: PMC7455824 DOI: 10.1155/2020/9494352] [Citation(s) in RCA: 69] [Impact Index Per Article: 17.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/06/2020] [Accepted: 07/31/2020] [Indexed: 12/11/2022]
Abstract
Astrocytes are the most populous glial cells in the central nervous system (CNS). They are essential to CNS physiology and play important roles in the maintenance of homeostasis, development of synaptic plasticity, and neuroprotection. Nevertheless, under the influence of certain factors, astrocytes may also exert detrimental effects through a process of reactive astrogliosis. Previous studies have shown that astrocytes have more than one type of polarization. Two types have been extensively researched. One is a damaging change that occurs under inflammation and has been termed A1 astrocyte, while the other is a restorative change that occurs under ischemic induction and was termed A2 astrocyte. Researchers are now increasingly paying attention to the role of astrocytes in spinal cord injury (SCI), degenerative diseases, chronic pain, neurological tumors, and other CNS disorders. In this review, we discuss (a) the characteristics of polarized astrocytes, (b) the relationship between astrocyte polarization and SCI, and (c) new implications of reactive astrogliosis for future SCI therapies.
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Affiliation(s)
- Xinyu Li
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No. 105, Jiefang Road, Jinan, Shandong 250013, China
| | - Meng Li
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No. 105, Jiefang Road, Jinan, Shandong 250013, China
| | - Lige Tian
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No. 105, Jiefang Road, Jinan, Shandong 250013, China
| | - Jianan Chen
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No. 105, Jiefang Road, Jinan, Shandong 250013, China
| | - Ronghan Liu
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No. 105, Jiefang Road, Jinan, Shandong 250013, China
| | - Bin Ning
- Jinan Central Hospital, Cheeloo College of Medicine, Shandong University, No. 105, Jiefang Road, Jinan, Shandong 250013, China
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22
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Zhang N, Zhang Z, He R, Li H, Ding S. GLAST-CreER T2 mediated deletion of GDNF increases brain damage and exacerbates long-term stroke outcomes after focal ischemic stroke in mouse model. Glia 2020; 68:2395-2414. [PMID: 32497340 DOI: 10.1002/glia.23848] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Revised: 05/07/2020] [Accepted: 05/07/2020] [Indexed: 01/01/2023]
Abstract
Focal ischemic stroke (FIS) is a leading cause of human death. Glial scar formation largely caused by reactive astrogliosis in peri-infarct region (PIR) is the hallmark of FIS. Glial cell-derived neurotrophic factor (GDNF) was originally isolated from a rat glioma cell-line supernatant and is a potent survival neurotrophic factor. Here, using CreERT2 -LoxP recombination technology, we generated inducible and astrocyte-specific GDNF conditional knockout (cKO), that is, GLAST-GDNF-/- cKO mice to investigate the effect of reactive astrocytes (RAs)-derived GDNF on neuronal death, brain damage, oxidative stress and motor function recovery after photothrombosis (PT)-induced FIS. Under non-ischemic conditions, we found that adult GLAST-GDNF-/- cKO mice exhibited significant lower numbers of Brdu+, Ki67+ cells, and DCX+ cells in the dentate gyrus (DG) in hippocampus than GDNF floxed (GDNFf/f ) control (Ctrl) mice, indicating endogenous astrocytic GDNF can promote adult neurogenesis. Under ischemic conditions, GLAST-GDNF-/- cKO mice had a significant increase in infarct volume, hippocampal damage and FJB+ degenerating neurons after PT as compared with the Ctrl mice. GLAST-GDNF-/- cKO mice also had lower densities of Brdu+ and Ki67+ cells in the PIR and exhibited larger behavioral deficits than the Ctrl mice. Mechanistically, GDNF deficiency in astrocytes increased oxidative stress through the downregulation of glucose-6-phosphate dehydrogenase (G6PD) in RAs. In summary, our study indicates that RAs-derived endogenous GDNF plays important roles in reducing brain damage and promoting brain recovery after FIS through neural regeneration and suggests that promoting anti-oxidant mechanism in RAs is a potential strategy in stroke therapy.
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Affiliation(s)
- Nannan Zhang
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
| | - Zhe Zhang
- Department of Biomedical, Biological and Chemical Engineering, University of Missouri, Columbia, Missouri, USA
| | - Rui He
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA
| | - Hailong Li
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA.,Department of Biomedical, Biological and Chemical Engineering, University of Missouri, Columbia, Missouri, USA
| | - Shinghua Ding
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri, USA.,Department of Biomedical, Biological and Chemical Engineering, University of Missouri, Columbia, Missouri, USA
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23
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Siracusa R, Fusco R, Cuzzocrea S. Astrocytes: Role and Functions in Brain Pathologies. Front Pharmacol 2019; 10:1114. [PMID: 31611796 PMCID: PMC6777416 DOI: 10.3389/fphar.2019.01114] [Citation(s) in RCA: 179] [Impact Index Per Article: 35.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2019] [Accepted: 08/30/2019] [Indexed: 12/16/2022] Open
Abstract
Astrocytes are a population of cells with distinctive morphological and functional characteristics that differ within specific areas of the brain. Postnatally, astrocyte progenitors migrate to reach their brain area and related properties. They have a regulatory role of brain functions that are implicated in neurogenesis and synaptogenesis, controlling blood-brain barrier permeability and maintaining extracellular homeostasis. Mature astrocytes also express some genes enriched in cell progenitors, suggesting they can retain proliferative potential. Considering heterogeneity of cell population, it is not surprising that their disorders are related to a wide range of different neuro-pathologies. Brain diseases are characterized by the active inflammatory state of the astrocytes, which is usually described as up-regulation of glial fibrillary acidic protein (GFAP). In particular, the loss of astrocytes function as a result of cellular senescence could have implications for the neurodegenerative disorders, such as Alzheimer disease and Huntington disease, and for the aging brain. Astrocytes can also drive the induction and the progression of the inflammatory state due to their Ca2+ signals and that it is strongly related to the disease severity/state. Moreover, they contribute to the altered neuronal activity in several frontal cortex pathologies such as ischemic stroke and epilepsy. There, we describe the current knowledge pertaining to astrocytes' role in brain pathologies and discuss the possibilities to target them as approach toward pharmacological therapies for neuro-pathologies.
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Affiliation(s)
- Rosalba Siracusa
- Department of Chemical, Biological, Pharmaceutical and Environmental Science, University of Messina, Messina, Italy
| | - Roberta Fusco
- Department of Chemical, Biological, Pharmaceutical and Environmental Science, University of Messina, Messina, Italy
| | - Salvatore Cuzzocrea
- Department of Chemical, Biological, Pharmaceutical and Environmental Science, University of Messina, Messina, Italy.,Department of Pharmacological and Physiological Science, Saint Louis University School of Medicine, Saint Louis, MO, United States
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24
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Murmu RP, Fordsmann JC, Cai C, Brazhe A, Thomsen KJ, Lauritzen M. Sensory Stimulation-Induced Astrocytic Calcium Signaling in Electrically Silent Ischemic Penumbra. Front Aging Neurosci 2019; 11:223. [PMID: 31496947 PMCID: PMC6712371 DOI: 10.3389/fnagi.2019.00223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Accepted: 08/07/2019] [Indexed: 11/14/2022] Open
Abstract
Middle cerebral artery occlusion (MCAO) induces ischemia characterized by a densely ischemic focus, and a less densely ischemic penumbral zone in which neurons and astrocytes display age-dependent dynamic variations in spontaneous Ca2+ activities. However, it is unknown whether penumbral nerve cells respond to sensory stimulation early after stroke onset, which is critical for understanding stimulation-induced stroke therapy. In this study, we investigated the ischemic penumbra’s capacity to respond to somatosensory input. We examined adult (3- to 4-month-old) and old (18- to 24-month-old) male mice at 2–4 h after MCAO, using two-photon microscopy to record somatosensory stimulation-induced neuronal and astrocytic Ca2+ signals in the ischemic penumbra. In both adult and old mice, MCAO abolished spontaneous and stimulation-induced electrical activity in the penumbra, and strongly reduced stimulation-induced Ca2+ responses in neuronal somas (35–82%) and neuropil (92–100%) in the penumbra. In comparison, after stroke, stimulation-induced astrocytic Ca2+ responses in the penumbra were only moderately reduced (by 54–62%) in adult mice, and were even better preserved (reduced by 31–38%) in old mice. Our results suggest that somatosensory stimulation evokes astrocytic Ca2+ activity in the ischemic penumbra. We hypothesize that the relatively preserved excitability of astrocytes, most prominent in aged mice, may modulate protection from ischemic infarcts during early somatosensory activation of an ischemic cortical area. Future neuroprotective efforts in stroke may target spontaneous or stimulation-induced activity of astrocytes in the ischemic penumbra.
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Affiliation(s)
- Reena P Murmu
- Translational Neurobiology Group, Department of Neuroscience, Panum Institute, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Jonas C Fordsmann
- Translational Neurobiology Group, Department of Neuroscience, Panum Institute, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Changsi Cai
- Translational Neurobiology Group, Department of Neuroscience, Panum Institute, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark
| | - Alexey Brazhe
- Faculty of Biology, Moscow State University, Moscow, Russia
| | - Kirsten J Thomsen
- Translational Neurobiology Group, Department of Neuroscience, Panum Institute, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark
| | - Martin Lauritzen
- Translational Neurobiology Group, Department of Neuroscience, Panum Institute, Center for Healthy Aging, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Neurophysiology, Rigshospitalet, Glostrup, Denmark
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25
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Adrenergic receptor antagonism induces neuroprotection and facilitates recovery from acute ischemic stroke. Proc Natl Acad Sci U S A 2019; 116:11010-11019. [PMID: 31097598 DOI: 10.1073/pnas.1817347116] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Spontaneous waves of cortical spreading depolarization (CSD) are induced in the setting of acute focal ischemia. CSD is linked to a sharp increase of extracellular K+ that induces a long-lasting suppression of neural activity. Furthermore, CSD induces secondary irreversible damage in the ischemic brain, suggesting that K+ homeostasis might constitute a therapeutic strategy in ischemic stroke. Here we report that adrenergic receptor (AdR) antagonism accelerates normalization of extracellular K+, resulting in faster recovery of neural activity after photothrombotic stroke. Remarkably, systemic adrenergic blockade before or after stroke facilitated functional motor recovery and reduced infarct volume, paralleling the preservation of the water channel aquaporin-4 in astrocytes. Our observations suggest that AdR blockers promote cerebrospinal fluid exchange and rapid extracellular K+ clearance, representing a potent potential intervention for acute stroke.
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26
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McConnell HL, Li Z, Woltjer RL, Mishra A. Astrocyte dysfunction and neurovascular impairment in neurological disorders: Correlation or causation? Neurochem Int 2019; 128:70-84. [PMID: 30986503 DOI: 10.1016/j.neuint.2019.04.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2019] [Revised: 04/08/2019] [Accepted: 04/09/2019] [Indexed: 12/14/2022]
Abstract
The neurovascular unit, consisting of neurons, astrocytes, and vascular cells, has become the focus of much discussion in the last two decades and emerging literature now suggests an association between neurovascular dysfunction and neurological disorders. In this review, we synthesize the known and suspected contributions of astrocytes to neurovascular dysfunction in disease. Throughout the brain, astrocytes are centrally positioned to dynamically mediate interactions between neurons and the cerebral vasculature, and play key roles in blood-brain barrier maintenance and neurovascular coupling. It is increasingly apparent that the changes in astrocytes in response to a variety of insults to brain tissue -collectively referred to as "reactive astrogliosis" - are not just an epiphenomenon restricted to morphological alterations, but comprise functional changes in astrocytes that contribute to the phenotype of neurological diseases with both beneficial and detrimental effects. In the context of the neurovascular unit, astrocyte dysfunction accompanies, and may contribute to, blood-brain barrier impairment and neurovascular dysregulation, highlighting the need to determine the exact nature of the relationship between astrocyte dysfunction and neurovascular impairments. Targeting astrocytes may represent a new strategy in combinatorial therapeutics for preventing the mismatch of energy supply and demand that often accompanies neurological disorders.
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Affiliation(s)
- Heather L McConnell
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States
| | - Zhenzhou Li
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States; Department of Anesthesiology, General Hospital of Ningxia Medical University, Yinchuan City, China
| | - Randall L Woltjer
- Department of Neuropathology, Oregon Health & Science University, Portland, OR, United States
| | - Anusha Mishra
- Knight Cardiovascular Institute, Oregon Health & Science University, Portland, OR, United States.
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Aberrant Calcium Signals in Reactive Astrocytes: A Key Process in Neurological Disorders. Int J Mol Sci 2019; 20:ijms20040996. [PMID: 30823575 PMCID: PMC6413203 DOI: 10.3390/ijms20040996] [Citation(s) in RCA: 85] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 02/20/2019] [Accepted: 02/21/2019] [Indexed: 02/06/2023] Open
Abstract
Astrocytes are abundant cells in the brain that regulate multiple aspects of neural tissue homeostasis by providing structural and metabolic support to neurons, maintaining synaptic environments and regulating blood flow. Recent evidence indicates that astrocytes also actively participate in brain functions and play a key role in brain disease by responding to neuronal activities and brain insults. Astrocytes become reactive in response to injury and inflammation, which is typically described as hypertrophy with increased expression of glial fibrillary acidic protein (GFAP). Reactive astrocytes are frequently found in many neurological disorders and are a hallmark of brain disease. Furthermore, reactive astrocytes may drive the initiation and progression of disease processes. Recent improvements in the methods to visualize the activity of reactive astrocytes in situ and in vivo have helped elucidate their functions. Ca2+ signals in reactive astrocytes are closely related to multiple aspects of disease and can be a good indicator of disease severity/state. In this review, we summarize recent findings concerning reactive astrocyte Ca2+ signals. We discuss the molecular mechanisms underlying aberrant Ca2+ signals in reactive astrocytes and the functional significance of aberrant Ca2+ signals in neurological disorders.
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28
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Abstract
Peripheral nerve injury causes maladaptive plasticity in the central nervous system and induces chronic pain. In addition to the injured limb, abnormal pain sensation can appear in the limb contralateral to the injury, called mirror image pain. Because synaptic remodeling in the primary somatosensory cortex (S1) has critical roles in the induction of chronic pain, cortical reorganization in the S1 ipsilateral to the injured limb may also accompany mirror image pain. To elucidate this, we conducted in vivo 2-photon calcium imaging of neuron and astrocyte activity in the ipsilateral S1 after a peripheral nerve injury. We found that cross-callosal inputs enhanced the activity of both S1 astrocytes and inhibitory neurons, whereas activity of excitatory neurons decreased. When local inhibitory circuits were blocked, astrocyte-dependent spine plasticity and allodynia were revealed. Thus, we propose that cortical astrocytes prime the induction of spine plasticity and mirror image pain after peripheral nerve injury. Moreover, this result suggests that cortical synaptic rewiring could be sufficient to cause allodynia on the uninjured periphery.
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29
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Tauchi M, Tejada de Rink MM, Fujioka H, Okayama S, Nakamura KI, Dietel B, Achenbach S, Kollmar R, Schwab S, Ushijima K, Harada H. Targeted Temperature Management: Peltier's Element-Based Focal Brain Cooling Protects Penumbra Neurons from Progressive Damage in Experimental Cerebral Ischemia. Ther Hypothermia Temp Manag 2018; 8:225-233. [DOI: 10.1089/ther.2017.0055] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Affiliation(s)
- Miyuki Tauchi
- Department of Neurology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
- Department of Molecular Neurology, and Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
- Department of Medicine 2–Cardiology and Angiology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Maria Mercedes Tejada de Rink
- Department of Anesthesiology, Kurume University School of Medicine, Kurume, Japan
- Neuroanesthesia Research Laboratory, Cognitive and Molecular Institute of Brain Diseases, Kurume University School of Medicine, Kurume, Japan
| | - Hiroshi Fujioka
- Department of Neurosurgery, Kanmon Medical Center, National Hospital Organization (NHO), Yamaguchi, Japan
| | - Satoko Okayama
- Division of Microscopic and Developmental Anatomy, Department of Anatomy, Kurume University School of Medicine, Kurume, Japan
| | - Kei-ichiro Nakamura
- Division of Microscopic and Developmental Anatomy, Department of Anatomy, Kurume University School of Medicine, Kurume, Japan
| | - Barbara Dietel
- Department of Medicine 2–Cardiology and Angiology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Stephan Achenbach
- Department of Medicine 2–Cardiology and Angiology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Rainer Kollmar
- Department of Neurology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Stefan Schwab
- Department of Neurology, Universitätsklinikum Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Kazuo Ushijima
- Department of Anesthesiology, Kurume University School of Medicine, Kurume, Japan
| | - Hideki Harada
- Department of Anesthesiology, Kurume University School of Medicine, Kurume, Japan
- Neuroanesthesia Research Laboratory, Cognitive and Molecular Institute of Brain Diseases, Kurume University School of Medicine, Kurume, Japan
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30
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Fordsmann JC, Murmu RP, Cai C, Brazhe A, Thomsen KJ, Zambach SA, Lønstrup M, Lind BL, Lauritzen M. Spontaneous astrocytic Ca 2+ activity abounds in electrically suppressed ischemic penumbra of aged mice. Glia 2018; 67:37-52. [PMID: 30427548 DOI: 10.1002/glia.23506] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Revised: 06/12/2018] [Accepted: 07/03/2018] [Indexed: 12/11/2022]
Abstract
Experimental focal cortical ischemic lesions consist of an ischemic core and a potentially salvageable peri-ischemic region, the ischemic penumbra. The activity of neurons and astrocytes is assumed to be suppressed in the penumbra because the electrical function is interrupted, but this is incompletely elucidated. Most experimental stroke studies used young adult animals, whereas stroke is prevalent in the elderly population. Using two-photon imaging in vivo, we here demonstrate extensive but electrically silent, spontaneous Ca2+ activity in neurons and astrocytes in the ischemic penumbra of 18- to 24-month-old mice 2-4 hr after middle cerebral artery occlusion. In comparison, stroke reduced spontaneous Ca2+ activity in neurons and astrocytes in adult mice (3-4 months of age). In aged mice, stroke increased astrocytic spontaneous Ca2+ activity considerably while neuronal spontaneous Ca2+ activity was unchanged. Blockade of action potentials and of purinergic receptors strongly reduced spontaneous Ca2+ activity in both neurons and astrocytes in the penumbra of old stroke mice. This indicates that stroke had a direct influence on mechanisms in presynaptic terminals and on purinergic signaling. Thus, highly dynamic variations in spontaneous Ca2+ activity characterize the electrically compromised penumbra, with remarkable differences between adult and old mice. The data are consistent with the notion that aged neurons and astrocytes take on a different phenotype than young mice. The increased activity of the aged astrocyte phenotype may be harmful to neurons. We suggest that the abundant spontaneous Ca2+ activity in astrocytes in the ischemic penumbra of old mice may be a novel target for neuroprotection strategies. A video abstract of this article can be found at https://youtu.be/AKlwKFsz1qE.
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Affiliation(s)
- Jonas Christoffer Fordsmann
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Reena Prity Murmu
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Changsi Cai
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Alexey Brazhe
- Faculty of Biology, Moscow State University, Moscow, Russia
| | - Kirsten Joan Thomsen
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup, Denmark
| | - Stefan Andreas Zambach
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Micael Lønstrup
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Barbara Lykke Lind
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark
| | - Martin Lauritzen
- Department of Neuroscience and Center for Healthy Aging, Panum Institute, University of Copenhagen, Copenhagen, Denmark.,Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup, Denmark
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31
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Matos M, Bosson A, Riebe I, Reynell C, Vallée J, Laplante I, Panatier A, Robitaille R, Lacaille JC. Astrocytes detect and upregulate transmission at inhibitory synapses of somatostatin interneurons onto pyramidal cells. Nat Commun 2018; 9:4254. [PMID: 30315174 PMCID: PMC6185912 DOI: 10.1038/s41467-018-06731-y] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Accepted: 09/12/2018] [Indexed: 01/14/2023] Open
Abstract
Astrocytes are important regulators of excitatory synaptic networks. However, astrocytes regulation of inhibitory synaptic systems remains ill defined. This is particularly relevant since GABAergic interneurons regulate the activity of excitatory cells and shape network function. To address this issue, we combined optogenetics and pharmacological approaches, two-photon confocal imaging and whole-cell recordings to specifically activate hippocampal somatostatin or paravalbumin-expressing interneurons (SOM-INs or PV-INs), while monitoring inhibitory synaptic currents in pyramidal cells and Ca2+ responses in astrocytes. We found that astrocytes detect SOM-IN synaptic activity via GABABR and GAT-3-dependent Ca2+ signaling mechanisms, the latter triggering the release of ATP. In turn, ATP is converted into adenosine, activating A1Rs and upregulating SOM-IN synaptic inhibition of pyramidal cells, but not PV-IN inhibition. Our findings uncover functional interactions between a specific subpopulation of interneurons, astrocytes and pyramidal cells, involved in positive feedback autoregulation of dendritic inhibition of pyramidal cells.
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Affiliation(s)
- Marco Matos
- Département de Neurosciences, Faculté de Médecine, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
| | - Anthony Bosson
- Département de Neurosciences, Faculté de Médecine, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
| | - Ilse Riebe
- Département de Neurosciences, Faculté de Médecine, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
| | - Clare Reynell
- Département de Neurosciences, Faculté de Médecine, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
| | - Joanne Vallée
- Département de Neurosciences, Faculté de Médecine, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
| | - Isabel Laplante
- Département de Neurosciences, Faculté de Médecine, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada
| | - Aude Panatier
- Neurocentre Magendie, Inserm U1215, 33077, Bordeaux, France
- Université de Bordeaux, 33077, Bordeaux, France
| | - Richard Robitaille
- Département de Neurosciences, Faculté de Médecine, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada.
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada.
| | - Jean-Claude Lacaille
- Département de Neurosciences, Faculté de Médecine, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada.
- Groupe de Recherche sur le Système Nerveux Central, Université de Montréal, PO Box 6128, Station Centre-Ville, Montreal, QC, H3C 3J7, Canada.
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32
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Sompol P, Norris CM. Ca 2+, Astrocyte Activation and Calcineurin/NFAT Signaling in Age-Related Neurodegenerative Diseases. Front Aging Neurosci 2018; 10:199. [PMID: 30038565 PMCID: PMC6046440 DOI: 10.3389/fnagi.2018.00199] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/12/2018] [Indexed: 12/12/2022] Open
Abstract
Mounting evidence supports a fundamental role for Ca2+ dysregulation in astrocyte activation. Though the activated astrocyte phenotype is complex, cell-type targeting approaches have revealed a number of detrimental roles of activated astrocytes involving neuroinflammation, release of synaptotoxic factors and loss of glutamate regulation. Work from our lab and others has suggested that the Ca2+/calmodulin dependent protein phosphatase, calcineurin (CN), provides a critical link between Ca2+ dysregulation and the activated astrocyte phenotype. A proteolyzed, hyperactivated form of CN appears at high levels in activated astrocytes in both human tissue and rodent tissue around regions of amyloid and vascular pathology. Similar upregulation of the CN-dependent transcription factor nuclear factor of activated T cells (NFAT4) also appears in activated astrocytes in mouse models of Alzheimer's disease (ADs) and traumatic brain injury (TBI). Major consequences of hyperactivated CN/NFAT4 signaling in astrocytes are neuroinflammation, synapse dysfunction and glutamate dysregulation/excitotoxicity, which will be covered in this review article.
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Affiliation(s)
- Pradoldej Sompol
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Christopher M Norris
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, United States.,Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, United States
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33
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Zhao X, Zhou K, Li Z, Nan W, Wang J, Xia Y, Zhang H. Knockdown of Ski decreased the reactive astrocytes proliferation in vitro induced by oxygen‐glucose deprivation/reoxygenation. J Cell Biochem 2018; 119:4548-4558. [DOI: 10.1002/jcb.26597] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/07/2017] [Indexed: 12/17/2022]
Affiliation(s)
- Xin Zhao
- The Second Clinical Medical College of Lanzhou UniversityLanzhouPR China
- Orthopaedics Key laboratory of Gansu ProvinceLanzhouPR China
| | - Kai‐Sheng Zhou
- The Second Clinical Medical College of Lanzhou UniversityLanzhouPR China
- Orthopaedics Key laboratory of Gansu ProvinceLanzhouPR China
| | - Zhong‐Hao Li
- The Second Clinical Medical College of Lanzhou UniversityLanzhouPR China
- Orthopaedics Key laboratory of Gansu ProvinceLanzhouPR China
| | - Wei Nan
- The Second Clinical Medical College of Lanzhou UniversityLanzhouPR China
- Orthopaedics Key laboratory of Gansu ProvinceLanzhouPR China
| | - Jing Wang
- Orthopaedics Key laboratory of Gansu ProvinceLanzhouPR China
| | - Ya‐Yi Xia
- The Second Clinical Medical College of Lanzhou UniversityLanzhouPR China
| | - Hai‐Hong Zhang
- The Second Clinical Medical College of Lanzhou UniversityLanzhouPR China
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34
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Saito K, Shigetomi E, Yasuda R, Sato R, Nakano M, Tashiro K, Tanaka KF, Ikenaka K, Mikoshiba K, Mizuta I, Yoshida T, Nakagawa M, Mizuno T, Koizumi S. Aberrant astrocyte Ca 2+ signals "AxCa signals" exacerbate pathological alterations in an Alexander disease model. Glia 2018; 66:1053-1067. [PMID: 29383757 DOI: 10.1002/glia.23300] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2017] [Revised: 12/12/2017] [Accepted: 01/10/2018] [Indexed: 12/21/2022]
Abstract
Alexander disease (AxD) is a rare neurodegenerative disorder caused by gain of function mutations in the glial fibrillary acidic protein (GFAP) gene. Accumulation of GFAP proteins and formation of Rosenthal fibers (RFs) in astrocytes are hallmarks of AxD. However, malfunction of astrocytes in the AxD brain is poorly understood. Here, we show aberrant Ca2+ responses in astrocytes as playing a causative role in AxD. Transcriptome analysis of astrocytes from a model of AxD showed age-dependent upregulation of GFAP, several markers for neurotoxic reactive astrocytes, and downregulation of Ca2+ homeostasis molecules. In situ AxD model astrocytes produced aberrant extra-large Ca2+ signals "AxCa signals", which increased with age, correlated with GFAP upregulation, and were dependent on stored Ca2+ . Inhibition of AxCa signals by deletion of inositol 1,4,5-trisphosphate type 2 receptors (IP3R2) ameliorated AxD pathogenesis. Taken together, AxCa signals in the model astrocytes would contribute to AxD pathogenesis.
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Affiliation(s)
- Kozo Saito
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Kofu, Yamanashi Prefecture, 400-8510, Japan.,Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Eiji Shigetomi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Kofu, Yamanashi Prefecture, 400-8510, Japan
| | - Rei Yasuda
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Ryuichi Sato
- Department of Genomic Medical Sciences, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Masakazu Nakano
- Department of Genomic Medical Sciences, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Kei Tashiro
- Department of Genomic Medical Sciences, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Kenji F Tanaka
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan.,Department of Neuropsychiatry, Keio University School of Medicine, Tokyo, Japan
| | - Kazuhiro Ikenaka
- Division of Neurobiology and Bioinformatics, National Institute for Physiological Sciences, Okazaki, Japan
| | - Katsuhiko Mikoshiba
- Laboratory for Developmental Neurobiology, RIKEN Brain Science Institute, Wako, Japan
| | - Ikuko Mizuta
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Tomokatsu Yoshida
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Masanori Nakagawa
- Department of Neurology, North Medical Center, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Toshiki Mizuno
- Department of Neurology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Kofu, Yamanashi Prefecture, 400-8510, Japan
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35
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Stokum JA, Kwon MS, Woo SK, Tsymbalyuk O, Vennekens R, Gerzanich V, Simard JM. SUR1-TRPM4 and AQP4 form a heteromultimeric complex that amplifies ion/water osmotic coupling and drives astrocyte swelling. Glia 2017; 66:108-125. [PMID: 28906027 DOI: 10.1002/glia.23231] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 07/23/2017] [Accepted: 08/23/2017] [Indexed: 12/17/2022]
Abstract
Astrocyte swelling occurs after central nervous system injury and contributes to brain swelling, which can increase mortality. Mechanisms proffered to explain astrocyte swelling emphasize the importance of either aquaporin-4 (AQP4), an astrocyte water channel, or of Na+ -permeable channels, which mediate cellular osmolyte influx. However, the spatio-temporal functional interactions between AQP4 and Na+ -permeable channels that drive swelling are poorly understood. We hypothesized that astrocyte swelling after injury is linked to an interaction between AQP4 and Na+ -permeable channels that are newly upregulated. Here, using co-immunoprecipitation and Förster resonance energy transfer, we report that AQP4 physically co-assembles with the sulfonylurea receptor 1-transient receptor potential melastatin 4 (SUR1-TRPM4) monovalent cation channel to form a novel heteromultimeric water/ion channel complex. In vitro cell-swelling studies using calcein fluorescence imaging of COS-7 cells expressing various combinations of AQP4, SUR1, and TRPM4 showed that the full tripartite complex, comprised of SUR1-TRPM4-AQP4, was required for fast, high-capacity transmembrane water transport that drives cell swelling, with these findings corroborated in cultured primary astrocytes. In a murine model of brain edema involving cold-injury to the cerebellum, we found that astrocytes newly upregulate SUR1-TRPM4, that AQP4 co-associates with SUR1-TRPM4, and that genetic inactivation of the solute pore of the SUR1-TRPM4-AQP4 complex blocked in vivo astrocyte swelling measured by diolistic labeling, thereby corroborating our in vitro functional studies. Together, these findings demonstrate a novel molecular mechanism involving the SUR1-TRPM4-AQP4 complex to account for bulk water influx during astrocyte swelling. These findings have broad implications for the understanding and treatment of AQP4-mediated pathological conditions.
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Affiliation(s)
- Jesse A Stokum
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland, 21201-1595
| | - Min S Kwon
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland, 21201-1595
| | - Seung K Woo
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland, 21201-1595
| | - Orest Tsymbalyuk
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland, 21201-1595
| | - Rudi Vennekens
- Department of Cellular and Molecular Medicine, Laboratory of Ion Channel Research, Katholieke Universiteit Leuven, Leuven, 3000, Belgium
| | - Volodymyr Gerzanich
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland, 21201-1595
| | - J Marc Simard
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland, 21201-1595.,Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland, 21201-1595.,Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, 21201-1595
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36
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Eto K, Kim SK, Takeda I, Nabekura J. The roles of cortical astrocytes in chronic pain and other brain pathologies. Neurosci Res 2017; 126:3-8. [PMID: 28870605 DOI: 10.1016/j.neures.2017.08.009] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 08/01/2017] [Accepted: 08/18/2017] [Indexed: 01/21/2023]
Abstract
Astrocytes are the most abundant cell type in the brain. Several decades ago, they were considered to be only support cells in the central nervous system. Recent studies using advanced technologies have clarified that astrocytes play more active roles in regulating neuronal function and remodeling synaptic structures by releasing molecules called gliotransmitters. In addition to various physiological functions, astrocytes are activated under disease conditions, such as chronic pain, releasing molecules that in turn cause reorganization of the central nervous system microstructure and disrupt behavior in pathological conditions. In the present review, we summarize cortical astrocyte function in chronic pain and other neurological disorders and discuss the role of astrocytes in brain pathologies.
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Affiliation(s)
- Kei Eto
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences, The Graduate School for Advanced Studies, Hayama, Kanagawa 240-0193, Japan
| | - Sun Kwang Kim
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Ikuko Takeda
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi 444-8585, Japan; Department of Physiological Sciences, The Graduate School for Advanced Studies, Hayama, Kanagawa 240-0193, Japan; Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo 102-0076, Japan.
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37
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Kim SK, Nabekura J, Koizumi S. Astrocyte-mediated synapse remodeling in the pathological brain. Glia 2017; 65:1719-1727. [PMID: 28569048 DOI: 10.1002/glia.23169] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 05/03/2017] [Accepted: 05/05/2017] [Indexed: 01/02/2023]
Abstract
Astrocytes, a major type of glia, reciprocally influence synaptic transmission and connectivity, forming the "tripartite synapses". Astrocytic metabotropic glutamate receptor (mGluR)-mediated Ca2+ waves and release of gliotransmitters or synaptogenic molecules mediate this neuron-glia interaction in the developing brain, but this signaling has been challenged for adult brain. However, cumulative evidence has suggested that mature astrocytes exhibit re-awakening of such immature phenotype in the pathological adult brain. This phenotypic change in astrocytes in response to injury may induce neural circuit and synapse plasticity. In this review article, we summarize astrocyte-mediated synapse remodeling during physiological development, discuss re-emergence of immature astrocytic signaling in adult pathological brain, and finally highlight its contribution to significant modification of synaptic connections correlating with functional progress of brain pathology.
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Affiliation(s)
- Sun Kwang Kim
- Department of Physiology, College of Korean Medicine, Kyung Hee University, Seoul, 02447, Korea
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, Okazaki, Aichi, 444-8585, Japan.,Department of Physiological Sciences, The Graduate School for Advanced Study, Hayama, Kanagawa, 240-0193, Japan.,Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo, 102-0076, Japan
| | - Schuichi Koizumi
- Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Tokyo, 102-0076, Japan.,Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi, 409-3898, Japan
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Petrovic-Djergovic D, Goonewardena SN, Pinsky DJ. Inflammatory Disequilibrium in Stroke. Circ Res 2017; 119:142-58. [PMID: 27340273 DOI: 10.1161/circresaha.116.308022] [Citation(s) in RCA: 183] [Impact Index Per Article: 26.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2016] [Accepted: 05/25/2016] [Indexed: 01/01/2023]
Abstract
Over the past several decades, there have been substantial advances in our knowledge of the pathophysiology of stroke. Understanding the benefits of timely reperfusion has led to the development of thrombolytic therapy as the cornerstone of current management of ischemic stroke, but there remains much to be learned about mechanisms of neuronal ischemic and reperfusion injury and associated inflammation. For ischemic stroke, novel therapeutic targets have continued to remain elusive. When considering modern molecular biological techniques, advanced translational stroke models, and clinical studies, a consistent pattern emerges, implicating perturbation of the immune equilibrium by stroke in both central nervous system injury and repair responses. Stroke triggers activation of the neuroimmune axis, comprised of multiple cellular constituents of the immune system resident within the parenchyma of the brain, leptomeninges, and vascular beds, as well as through secretion of biological response modifiers and recruitment of immune effector cells. This neuroimmune activation can directly impact the initiation, propagation, and resolution phases of ischemic brain injury. To leverage a potential opportunity to modulate local and systemic immune responses to favorably affect the stroke disease curve, it is necessary to expand our mechanistic understanding of the neuroimmune axis in ischemic stroke. This review explores the frontiers of current knowledge of innate and adaptive immune responses in the brain and how these responses together shape the course of ischemic stroke.
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Affiliation(s)
- Danica Petrovic-Djergovic
- From the Departments of Internal Medicine (D.P.-D., S.N.G., D.J.P.) and Molecular and Integrative Physiology (D.J.P.), University of Michigan, Ann Arbor
| | - Sascha N Goonewardena
- From the Departments of Internal Medicine (D.P.-D., S.N.G., D.J.P.) and Molecular and Integrative Physiology (D.J.P.), University of Michigan, Ann Arbor
| | - David J Pinsky
- From the Departments of Internal Medicine (D.P.-D., S.N.G., D.J.P.) and Molecular and Integrative Physiology (D.J.P.), University of Michigan, Ann Arbor.
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Lee IJ, Yang YC, Hsu JW, Chang WT, Chuang YJ, Liau I. Zebrafish model of photochemical thrombosis for translational research and thrombolytic screening in vivo. JOURNAL OF BIOPHOTONICS 2017; 10:494-502. [PMID: 27174426 DOI: 10.1002/jbio.201500287] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2015] [Revised: 04/22/2016] [Accepted: 04/22/2016] [Indexed: 06/05/2023]
Abstract
Acute thromboembolic diseases remain the major global cause of death or disability. Although an array of thrombolytic and antithrombotic drugs has been approved to treat or prevent thromboembolic diseases, many more drugs that target specific clotting mechanisms are under development. Here a novel zebrafish model of photochemical thrombosis is reported and its prospective application for the screening and preclinical testing of thrombolytic agents in vivo is demonstrated. Through photochemical excitation, a thrombus was induced to form at a selected section of the dorsal aorta of larval zebrafish, which had been injected with photosensitizers. Such photochemical thrombosis can be consistently controlled to occlude partially or completely the targeted blood vessel. Detailed mechanistic tests indicate that the zebrafish model of photochemical thrombosis exhibits essential features of classical coagulation and a thrombolytic pathway. For demonstration, tissue plasminogen activator (tPA), a clinically feasible thrombolytic agent, was shown to effectively dissolve photochemically induced blood clots. In light of the numerous unique advantages of zebrafish as a model organism, our approach is expected to benefit not only the development of novel thrombolytic and antithrombotic strategies but also the fundamental or translational research targeting hereditary thrombotic or coagulation disorders.
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Affiliation(s)
- I-Ju Lee
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Yi-Cyun Yang
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Jia-Wen Hsu
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu, 300, Taiwan
| | - Wei-Tien Chang
- Department of Emergency Medicine and Cardiovascular Center, National Taiwan University Hospital and College of Medicine, Taipei, 100, Taiwan
| | - Yung-Jen Chuang
- Department of Medical Science and Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsinchu, 300, Taiwan
| | - Ian Liau
- Department of Applied Chemistry and Institute of Molecular Science, National Chiao Tung University, Hsinchu, 300, Taiwan
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Morrison HW, Filosa JA. Sex differences in astrocyte and microglia responses immediately following middle cerebral artery occlusion in adult mice. Neuroscience 2016; 339:85-99. [PMID: 27717807 PMCID: PMC5118180 DOI: 10.1016/j.neuroscience.2016.09.047] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Revised: 09/19/2016] [Accepted: 09/27/2016] [Indexed: 12/31/2022]
Abstract
Epidemiological studies report that infarct size is decreased and stroke outcomes are improved in young females when compared to males. However, mechanistic insight is lacking. We posit that sex-specific differences in glial cell functions occurring immediately after ischemic stroke are a source of dichotomous outcomes. In this study we assessed astrocyte Ca2+ dynamics, aquaporin 4 (AQP4) polarity, S100β expression pattern, as well as, microglia morphology and phagocytic marker CD11b in male and female mice following 60min of middle cerebral artery (MCA) occlusion. We reveal sex differences in the frequency of intracellular astrocyte Ca2+ elevations (F(1,86)=8.19, P=0.005) and microglia volume (F(1,40)=12.47, P=0.009) immediately following MCA occlusion in acute brain slices. Measured in fixed tissue, AQP4 polarity was disrupted (F(5,86)=3.30, P=0.009) and the area of non-S100β immunoreactivity increased in ipsilateral brain regions after 60min of MCA occlusion (F(5,86)=4.72, P=0.007). However, astrocyte changes were robust in male mice when compared to females. Additional sex differences were discovered regarding microglia phagocytic receptor CD11b. In sham mice, constitutively high CD11b immunofluorescence was observed in females when compared to males (P=0.03). When compared to sham, only male mice exhibited an increase in CD11b immunoreactivity after MCA occlusion (P=0.006). We posit that a sex difference in the presence of constitutive CD11b has a role in determining male and female microglia phagocytic responses to ischemia. Taken together, these findings are critical to understanding potential sex differences in glial physiology as well as stroke pathobiology which are foundational for the development of future sex-specific stroke therapies.
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Affiliation(s)
- Helena W Morrison
- Augusta University, 1120 15th Street, Augusta, GA 30912, United States.
| | - Jessica A Filosa
- Augusta University, 1120 15th Street, Augusta, GA 30912, United States.
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Zhang H, Xiao J, Hu Z, Xie M, Wang W, He D. Blocking transient receptor potential vanilloid 2 channel in astrocytes enhances astrocyte-mediated neuroprotection after oxygen-glucose deprivation and reoxygenation. Eur J Neurosci 2016; 44:2493-2503. [PMID: 27468746 DOI: 10.1111/ejn.13352] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2016] [Revised: 07/13/2016] [Accepted: 07/23/2016] [Indexed: 01/14/2023]
Abstract
Astrocytes play important roles in homeostatic regulation in the central nervous system and are reported to influence the outcome of ischemic injury. Regulating Ca2+ signaling of astrocytes is a promising strategy for stroke therapy. Herein, we report for the first time that transient receptor potential vanilloid 2 (TRPV2), a Ca2+ -permeable channel that is important in osmotic balance regulation, expresses in rat cortical astrocytes by immunofluorescence. Moreover, oxygen-glucose deprivation and reoxygenation (OGD/R) treatment enhanced the expression. The TRPV2 is functional because Ca2+ imaging showed that activating the TRPV2 channel in cultured astrocytes increased intracellular Ca2+ level and the increment of intracellular Ca2+ level expanded when astrocytes were treated with OGD/R. Staining with 5-ethynyl-2'-deoxyuridine (EdU) revealed that while blocking the TRPV2, it promoted the proliferation of astrocytes. Additionally, blocking the TRPV2 in astrocytes increased the synthesis of nerve growth factor (NGF) mRNA and the secretion of NGF by real-time PCR and enzyme-linked immunosorbent assay respectively. We further found that the increased secretion of NGF could be reversed by c-JunN-terminalkinase (JNK) inhibitor and blocking the TRPV2 caused the phosphorylation of JNK. These indicated that blocking the TRPV2 induced NGF secretion via the mitogen-activated protein kinase (MAPK)-JNK signaling pathway. As the promoted proliferation of astrocytes and secretion of NGF were reported to have neuroprotective effects in the early stage of stroke, we concluded that targeting the TRPV2 channel in astrocytes might be a potential new therapeutic strategy in ischemic stroke.
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Affiliation(s)
- Han Zhang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, Hubei, 430030, China
| | - Jun Xiao
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, Hubei, 430030, China
| | - Zheng Hu
- Department of Obstetrics and Gynecology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Minjie Xie
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, Hubei, 430030, China
| | - Wei Wang
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, Hubei, 430030, China
| | - Dan He
- Department of Neurology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, 1095 Jiefang Avenue, Wuhan, Hubei, 430030, China. .,Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
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Dysfunctional Calcium and Glutamate Signaling in Striatal Astrocytes from Huntington's Disease Model Mice. J Neurosci 2016; 36:3453-70. [PMID: 27013675 DOI: 10.1523/jneurosci.3693-15.2016] [Citation(s) in RCA: 152] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Accepted: 01/07/2016] [Indexed: 01/14/2023] Open
Abstract
UNLABELLED Astrocytes tile the entire CNS, but their functions within neural circuits in health and disease remain incompletely understood. We used genetically encoded Ca(2+)and glutamate indicators to explore the rules for astrocyte engagement in the corticostriatal circuit of adult wild-type (WT) and Huntington's disease (HD) model mice at ages not accompanied by overt astrogliosis (at approximately postnatal days 70-80). WT striatal astrocytes displayed extensive spontaneous Ca(2+)signals, but did not respond to cortical stimulation, implying that astrocytes were largely disengaged from cortical input in healthy tissue. In contrast, in HD model mice, spontaneous Ca(2+)signals were significantly reduced in frequency, duration, and amplitude, but astrocytes responded robustly to cortical stimulation with evoked Ca(2+)signals. These action-potential-dependent astrocyte Ca(2+)signals were mediated by neuronal glutamate release during cortical stimulation, accompanied by prolonged extracellular glutamate levels near astrocytes and tightly gated by Glt1 glutamate transporters. Moreover, dysfunctional Ca(2+)and glutamate signaling that was observed in HD model mice was largely, but not completely, rescued by astrocyte specific restoration of Kir4.1, emphasizing the important contributions of K(+)homeostatic mechanisms that are known to be reduced in HD model mice. Overall, our data show that astrocyte engagement in the corticostriatal circuit is markedly altered in HD. Such prodromal astrocyte dysfunctions may represent novel therapeutic targets in HD and other brain disorders. SIGNIFICANCE STATEMENT We report how early-onset astrocyte dysfunction without detectable astrogliosis drives disease-related processes in a mouse model of Huntington's disease (HD). The cellular mechanisms involve astrocyte homeostasis and signaling mediated by Kir4.1, Glt1, and Ca(2+) The data show that the rules for astrocyte engagement in a neuronal circuit are fundamentally altered in a brain disease caused by a known molecular defect and that fixing early homeostasis dysfunction remedies additional cellular deficits. Overall, our data suggest that key aspects of altered striatal function associated with HD may be triggered, at least in part, by dysfunctional astrocytes, thereby providing details of an emerging striatal microcircuit mechanism in HD. Such prodromal changes in astrocytes may represent novel therapeutic targets.
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Zheng M, Lei H, Cui Y, Yang D, Wang L, Wang Z. Clinical efficacy and safety of hypernormal shortened door to needle time (DNT) plus individualized low-dose alteplase therapy in treating acute ischemic stroke. Pak J Med Sci 2016; 32:811-6. [PMID: 27648019 PMCID: PMC5017082 DOI: 10.12669/pjms.324.9518] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2015] [Revised: 04/18/2016] [Accepted: 06/30/2016] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVE This study aims to observe the clinical efficacies of hyper-early low-dose alteplase thrombolysis in treating acute ischemic stroke (AIS). METHODS Two hundred twenty AIS patients were randomly divided into group A (90 cases), group B (90 cases), and group C (40 cases). The National Institutes of Health Stroke Scale (NIHSS) scores, mRS score-evaluated prognosis, intracranial hemorrhage, and mortality of the three groups were observed before and after the treatment. RESULTS The NIHSS scores of the three groups were significantly reduced after the treatment (P<0.05), among which the NIHSS score of group A was the lowest (P<0.05); and the difference between group B and C was not significant (P>0.05). The incidence of such complications as cerebral hemorrhage in the three groups was low, and there was no significant difference among the groups (P>0.05). The modified Rankin Scale (mRS)scores of the three groups showed that group A had much better prognosis than group B and C, while the difference between group B and group C was not significant. CONCLUSIONS The hyper-early low-dose alteplase thrombolysis was safe and effective in Acute ischemic stroke (AIS).
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Affiliation(s)
- Mei Zheng
- Yansen Cui, Department of Emergency, Linyi People’s Hospital, Linyi 276000, China
| | - Hongyan Lei
- Hongyan Lei, Department of Emergency, Linyi People’s Hospital, Linyi 276000, China
| | - Yansen Cui
- Yansen Cui, Department of Emergency, Linyi People’s Hospital, Linyi 276000, China
| | - Daiqun Yang
- Daiqun Yang, Department of Emergency, Linyi People’s Hospital, Linyi 276000, China
| | - Liquang Wang
- Liquang Wang, Department of Emergency, Linyi People’s Hospital, Linyi 276000, China
| | - Ziran Wang
- Ziran Wang, Department of Emergency, Linyi People’s Hospital, Linyi 276000, China
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Xie Z, Shi M, Zhang C, Zhao H, Hui H, Zhao G. Ginsenoside Rd Protects Against Cerebral Ischemia-Reperfusion Injury Via Decreasing the Expression of the NMDA Receptor 2B Subunit and its Phosphorylated Product. Neurochem Res 2016; 41:2149-59. [PMID: 27165636 DOI: 10.1007/s11064-016-1930-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Revised: 04/09/2016] [Accepted: 04/18/2016] [Indexed: 12/13/2022]
Abstract
Ginsenoside Rd (GSRd) is one of the active ingredients in ginseng. Recent studies have shown that GSRd can protect against cerebral ischemia through several pathways, one of which is mediated by the N-methyl-D-aspartate receptor (NMDAR). In this study, we aimed to investigate the effects of GSRd on the phosphorylation of the NMDAR 2B subunit (NR2B subunit) in cerebral ischemia. Ischemia-reperfusion injury (IRI) models induced by transient middle cerebral artery occlusion (MCAO) and oxygen glucose deprivation (OGD) were used to mimic in vivo or in vitro injury during cerebral ischemia. The models were pretreated or post-treated with GSRd after MCAO or OGD. As a vehicle control, 1,3-propanediol was used. The expression levels of the NR2B subunit and the phosphorylated NR2B subunit were determined using western blotting. GSRd significantly improved the behavior score, infarct volume, and viability of the cultured neurons after ischemia. GSRd inhibited the hyperphosphorylation of NR2B subunit and decreased the expression levels of NR2B subunit in cell membrane but did not change their levels in the total proteins after IRI. GSRd protected Sprague-Dawley rats and cultured neurons from IRI via inhibiting the hyperphosphorylation of NR2B subunit and decreasing its expression levels in cell membrane.
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Affiliation(s)
- Zhen Xie
- Department of Neurology, Xijing Hospital, The Fourth Military Medical University, Xi'an, China.,Department 2 of Neurology, Shaanxi Provincial People's Hospital, Xi'an, China
| | - Ming Shi
- Department of Neurology, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Chen Zhang
- Department of Neurology, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Haibo Zhao
- Department of Neurology, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Hao Hui
- Department of Neurology, Xijing Hospital, The Fourth Military Medical University, Xi'an, China
| | - Gang Zhao
- Department of Neurology, Xijing Hospital, The Fourth Military Medical University, Xi'an, China.
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Lee W, Parpura V. Spatio-temporal characteristics of metabotropic glutamate receptor 5 traffic at or near the plasma membrane in astrocytes. Glia 2016; 64:1050-65. [PMID: 27014856 DOI: 10.1002/glia.22982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Revised: 02/07/2016] [Accepted: 02/10/2016] [Indexed: 12/22/2022]
Abstract
Astrocytes can sense extracellular glutamate and respond to it by elevating their intracellular Ca(2+) levels via the activation of G-protein coupled receptors, such as metabotropic glutamate receptor 5 (mGluR5), which, during early postnatal development, is the primary receptor responsible for glutamatergic signaling in astrocytes. However, the detailed spatio-temporal characteristics of mGluR5 traffic at or near the plasma membrane of astrocytes are not well understood. To address this issue, we expressed recombinant fluorescent protein chimera of mGluR5 and used total internal reflection fluorescence microscopy on rat visual cortical astrocytes in culture. We used astrocytes lacking major processes, otherwise posing as a diffusion barrier, to infer into the general dynamics of this receptor. We found that plasmalemmal mGluR5 clusters in distinct areas, the size, and initial spatio-temporal level of occupancy of which dictated mGluR5 trafficking characteristics upon glutamate stimulation. These findings will be valuable in the interpretation of point-to-point information transfer and volume transmission between astrocytes and neurons, as well as that of paracrine signaling within astrocytic networks.
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Affiliation(s)
- William Lee
- Department of Neurobiology, Center for Glial Biology in Medicine, Atomic Force Microscopy and Nanotechnology Laboratories, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Alabama
| | - Vladimir Parpura
- Department of Neurobiology, Center for Glial Biology in Medicine, Atomic Force Microscopy and Nanotechnology Laboratories, Civitan International Research Center, Evelyn F. McKnight Brain Institute, University of Alabama at Birmingham, Alabama
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Hosseini SM, Farahmandnia M, Kazemi S, Shakibajahromi B, Sarvestani FS, Khodabande Z. A Novel Cell Therapy Method for Recovering after Brain Stroke in Rats. Int J Stem Cells 2015; 8:191-9. [PMID: 26634067 PMCID: PMC4651283 DOI: 10.15283/ijsc.2015.8.2.191] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
BACKGROUND Nowadays, stroke leads to a significant part of the adult mortality and morbidity and also it could result in some neurological deficits in the patients' lives. Cell therapy has opened a new approach to treat the brain ischemia and reduce its terrible effects on the patients' lives. There are several articles which show that the cell therapy could be beneficial for treating brain stroke. In this study, we have planned to present a new cell therapy method for stroke by administration of Mesenchymal stem cells and differentiated neural stem cells without astrocytes. METHOD AND MATERIALS The Mesenchymal stem cells were isolated from tibia and femur of a 250~300 g rat and they were cultured in DMEM/F12, 10% fetal bovine serum, 1% Pen/Strep. Neural stem cells were isolated from 14 days rat embryo ganglion eminence and were cultured in NSA media containing Neurobasal, 2% B27, bFGF 10 ng/ml and EGF 20 ng/ml after 5 days they formed some neurospheres. The isolated neural stem cells were differentiated to neural lineages by adding 5% fetal bovine serum to their culture media. After 48 hours the astrocytes were depleted by using MACS kit. RESULTS The group that received Mesenchymal stem cells systemically and differentiated neural stem cells without astrocytes had the best neurological outcomes and the least infarct volume and apoptosis. It could be understood that this cell therapy method might cause almost full recovery after brain stoke. CONCLUSION Using combination cell therapy with Mesenchymal stem cells and differentiated neural stem cells with removed astrocyte could provide a novel method for curing brain stroke.
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Affiliation(s)
- Seyed Mojtaba Hosseini
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran ; Cell & Molecular Medicine Student Research Group, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran ; Stem Cell Laboratory, Department of Anatomy, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Farahmandnia
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran ; Cell & Molecular Medicine Student Research Group, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Sepehr Kazemi
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran ; Cell & Molecular Medicine Student Research Group, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Benafshe Shakibajahromi
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran ; Cell & Molecular Medicine Student Research Group, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Fatemeh Sabet Sarvestani
- Student Research Committee, Shiraz University of Medical Sciences, Shiraz, Iran ; Cell & Molecular Medicine Student Research Group, Medical School, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Zahra Khodabande
- Trangenic Technology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
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Li H, Xie Y, Zhang N, Yu Y, Zhang Q, Ding S. Disruption of IP₃R2-mediated Ca²⁺ signaling pathway in astrocytes ameliorates neuronal death and brain damage while reducing behavioral deficits after focal ischemic stroke. Cell Calcium 2015; 58:565-76. [PMID: 26433454 DOI: 10.1016/j.ceca.2015.09.004] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2015] [Revised: 09/19/2015] [Accepted: 09/21/2015] [Indexed: 12/12/2022]
Abstract
Inositol trisphosphate receptor (IP3R)-mediated intracellular Ca(2+) increase is the major Ca(2+) signaling pathway in astrocytes in the central nervous system (CNS). Ca(2+) increases in astrocytes have been found to modulate neuronal function through gliotransmitter release. We previously demonstrated that astrocytes exhibit enhanced Ca(2+) signaling in vivo after photothrombosis (PT)-induced ischemia, which is largely due to the activation of G-protein coupled receptors (GPCRs). The aim of this study is to investigate the role of astrocytic IP3R-mediated Ca(2+) signaling in neuronal death, brain damage and behavior outcomes after PT. For this purpose, we conducted experiments using homozygous type 2 IP3R (IP3R2) knockout (KO) mice. Histological and immunostaining studies showed that IP3R2 KO mice were indeed deficient in IP3R2 in astrocytes and exhibited normal brain cytoarchitecture. IP3R2 KO mice also had the same densities of S100β+ astrocytes and NeuN+ neurons in the cortices, and exhibited the same glial fibrillary acidic protein (GFAP) and glial glutamate transporter (GLT-1) levels in the cortices and hippocampi as compared with wild type (WT) mice. Two-photon (2-P) imaging showed that IP3R2 KO mice did not exhibit ATP-induced Ca(2+) waves in vivo in the astrocytic network, which verified the disruption of IP3R-mediated Ca(2+) signaling in astrocytes of these mice. When subject to PT, IP3R2 KO mice had smaller infarction than WT mice in acute and chronic phases of ischemia. IP3R2 KO mice also exhibited less neuronal apoptosis, reactive astrogliosis, and tissue loss than WT mice. Behavioral tests, including cylinder, hanging wire, pole and adhesive tests, showed that IP3R2 KO mice exhibited reduced functional deficits after PT. Collectively, our study demonstrates that disruption of astrocytic Ca(2+) signaling by deleting IP3R2s has beneficial effects on neuronal and brain protection and functional deficits after stroke. These findings reveal a novel non-cell-autonomous neuronal and brain protective function of astrocytes in ischemic stroke, whereby suggest that the astrocytic IP3R2-mediated Ca(2+) signaling pathway might be a promising target for stroke therapy.
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Affiliation(s)
- Hailong Li
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, MO 65211, United States; Department of Bioengineering, University of Missouri-Columbia, MO 65211, United States
| | - Yicheng Xie
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, MO 65211, United States; Department of Bioengineering, University of Missouri-Columbia, MO 65211, United States
| | - Nannan Zhang
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, MO 65211, United States
| | - Yang Yu
- Department of Bioengineering, University of Missouri-Columbia, MO 65211, United States
| | - Qiao Zhang
- Department of Bioengineering, University of Missouri-Columbia, MO 65211, United States
| | - Shinghua Ding
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, MO 65211, United States; Department of Bioengineering, University of Missouri-Columbia, MO 65211, United States.
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Eusemann TN, Willmroth F, Fiebich B, Biber K, van Calker D. Adenosine Receptors Differentially Regulate the Expression of Regulators of G-Protein Signalling (RGS) 2, 3 and 4 in Astrocyte-Like Cells. PLoS One 2015; 10:e0134934. [PMID: 26263491 PMCID: PMC4532427 DOI: 10.1371/journal.pone.0134934] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Accepted: 07/15/2015] [Indexed: 11/30/2022] Open
Abstract
The “regulators of g-protein signalling” (RGS) comprise a large family of proteins that limit by virtue of their GTPase accelerating protein domain the signal transduction of G-protein coupled receptors. RGS proteins have been implicated in various neuropsychiatric diseases such as schizophrenia, drug abuse, depression and anxiety and aggressive behaviour. Since conditions associated with a large increase of adenosine in the brain such as seizures or ischemia were reported to modify the expression of some RGS proteins we hypothesized that adenosine might regulate RGS expression in neural cells. We measured the expression of RGS-2,-3, and -4 in both transformed glia cells (human U373 MG astrocytoma cells) and in primary rat astrocyte cultures stimulated with adenosine agonists. Expression of RGS-2 mRNA as well as RGS2 protein was increased up to 30-fold by adenosine agonists in astrocytes. The order of potency of agonists and the blockade by the adenosine A2B-antagonist MRS1706 indicated that this effect was largely mediated by adenosine A2B receptors. However, a smaller effect was observed due to activation of adenosine A2A receptors. In astrocytoma cells adenosine agonists elicited an increase in RGS-2 expression solely mediated by A2B receptors. Expression of RGS-3 was inhibited by adenosine agonists in both astrocytoma cells and astrocytes. However while this effect was mediated by A2B receptors in astrocytoma cells it was mediated by A2A receptors in astrocytes as assessed by the order of potency of agonists and selective blockade by the specific antagonists MRS1706 and ZM241385 respectively. RGS-4 expression was inhibited in astrocytoma cells but enhanced in astrocytes by adenosine agonists.
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Affiliation(s)
- Till Nicolas Eusemann
- Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Freiburg, Germany
| | - Frank Willmroth
- Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Freiburg, Germany
| | - Bernd Fiebich
- Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Freiburg, Germany
| | - Knut Biber
- Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Freiburg, Germany
| | - Dietrich van Calker
- Department of Psychiatry and Psychotherapy, University of Freiburg Medical Center, Freiburg, Germany
- * E-mail:
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Decrock E, De Bock M, Wang N, Bultynck G, Giaume C, Naus CC, Green CR, Leybaert L. Connexin and pannexin signaling pathways, an architectural blueprint for CNS physiology and pathology? Cell Mol Life Sci 2015; 72:2823-51. [PMID: 26118660 PMCID: PMC11113968 DOI: 10.1007/s00018-015-1962-7] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 06/11/2015] [Indexed: 02/06/2023]
Abstract
The central nervous system (CNS) is composed of a highly heterogeneous population of cells. Dynamic interactions between different compartments (neuronal, glial, and vascular systems) drive CNS function and allow to integrate and process information as well as to respond accordingly. Communication within this functional unit, coined the neuro-glio-vascular unit (NGVU), typically relies on two main mechanisms: direct cell-cell coupling via gap junction channels (GJCs) and paracrine communication via the extracellular compartment, two routes to which channels composed of transmembrane connexin (Cx) or pannexin (Panx) proteins can contribute. Multiple isoforms of both protein families are present in the CNS and each CNS cell type is characterized by a unique Cx/Panx portfolio. Over the last two decades, research has uncovered a multilevel platform via which Cxs and Panxs can influence different cellular functions within a tissue: (1) Cx GJCs enable a direct cell-cell communication of small molecules, (2) Cx hemichannels and Panx channels can contribute to autocrine/paracrine signaling pathways, and (3) different structural domains of these proteins allow for channel-independent functions, such as cell-cell adhesion, interactions with the cytoskeleton, and the activation of intracellular signaling pathways. In this paper, we discuss current knowledge on their multifaceted contribution to brain development and to specific processes in the NGVU, including synaptic transmission and plasticity, glial signaling, vasomotor control, and blood-brain barrier integrity in the mature CNS. By highlighting both physiological and pathological conditions, it becomes evident that Cxs and Panxs can play a dual role in the CNS and that an accurate fine-tuning of each signaling mechanism is crucial for normal CNS physiology.
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Affiliation(s)
- Elke Decrock
- Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B, 3rd floor), 9000 Ghent, Belgium
| | - Marijke De Bock
- Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B, 3rd floor), 9000 Ghent, Belgium
| | - Nan Wang
- Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B, 3rd floor), 9000 Ghent, Belgium
| | - Geert Bultynck
- Laboratory of Molecular and Cellular Signalling, Department of Cellular and Molecular Medicine, KU Leuven, Louvain, Belgium
| | - Christian Giaume
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, 75231 Paris Cedex 05, France
- University Pierre et Marie
Curie, ED, N°158, 75005 Paris, France
- MEMOLIFE Laboratory of Excellence and Paris Science Lettre Research University, 75005 Paris, France
| | - Christian C. Naus
- Department of Cellular and Physiological Sciences, Faculty of Medicine, University of British Columbia, Vancouver, BC V6T 1Z3 Canada
| | - Colin R. Green
- Department of Ophthalmology, The University of Auckland, Auckland, New Zealand
| | - Luc Leybaert
- Physiology Group, Department of Basic Medical Sciences, Ghent University, De Pintelaan 185 (Block B, 3rd floor), 9000 Ghent, Belgium
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Murphy TH. Two-Photon Imaging of Neuronal Structural Plasticity in Mice during and after Ischemia. Cold Spring Harb Protoc 2015; 2015:548-57. [PMID: 26034310 DOI: 10.1101/pdb.prot087486] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
To gain insight into the dendritic structural changes that occur within minutes of ischemia, as well as circuit-level plasticity that occurs over days to weeks, it is necessary to devise stroke models for anesthetized transgenic mice that are compatible with in vivo imaging methods. In particular, we are interested in examining events during the first few minutes of ischemia that are associated with a wave of ischemic depolarization. Given the short latency to ischemic depolarization (∼2 min), we have found it necessary to develop ischemia models that can be initiated while the animal is within the two-photon microscope for in vivo imaging. We describe both a global ischemia model and a targeted photothrombotic ischemia model in green fluorescent protein- and yellow fluorescent protein-expressing transgenic mice in which in vivo imaging of dendritic structure can be performed. The advantage of the global model is the speed with which ischemia can be induced and reversed, whereas the focal model lacks precise temporal control but can be targeted to a select region.
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