101
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The Role of SVZ Stem Cells in Glioblastoma. Cancers (Basel) 2019; 11:cancers11040448. [PMID: 30934929 PMCID: PMC6521108 DOI: 10.3390/cancers11040448] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2019] [Revised: 03/22/2019] [Accepted: 03/26/2019] [Indexed: 12/27/2022] Open
Abstract
As most common primary brain cancer, glioblastoma is also the most aggressive and malignant form of cancer in the adult central nervous system. Glioblastomas are genetic and transcriptional heterogeneous tumors, which in spite of intensive research are poorly understood. Over the years conventional therapies failed to affect a cure, resulting in low survival rates of affected patients. To improve the clinical outcome, an important approach is to identify the cells of origin. One potential source for these are neural stem cells (NSCs) located in the subventricular zone, which is one of two niches in the adult nervous system where NSCs with the capacity of self-renewal and proliferation reside. These cells normally give rise to neuronal as well as glial progenitor cells. This review summarizes current findings about links between NSCs and cancer stem cells in glioblastoma and discusses current therapeutic approaches, which arise as a result of identifying the cell of origin in glioblastoma.
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102
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Park S, Loke G, Fink Y, Anikeeva P. Flexible fiber-based optoelectronics for neural interfaces. Chem Soc Rev 2019; 48:1826-1852. [PMID: 30815657 DOI: 10.1039/c8cs00710a] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Neurological and psychiatric conditions pose an increasing socioeconomic burden on our aging society. Our ability to understand and treat these conditions relies on the development of reliable tools to study the dynamics of the underlying neural circuits. Despite significant progress in approaches and devices to sense and modulate neural activity, further refinement is required on the spatiotemporal resolution, cell-type selectivity, and long-term stability of neural interfaces. Guided by the principles of neural transduction and by the materials properties of the neural tissue, recent advances in neural interrogation approaches rely on flexible and multifunctional devices. Among these approaches, multimaterial fibers have emerged as integrated tools for sensing and delivering of multiple signals to and from the neural tissue. Fiber-based neural probes are produced by thermal drawing process, which is the manufacturing approach used in optical fiber fabrication. This technology allows straightforward incorporation of multiple functional components into microstructured fibers at the level of their macroscale models, preforms, with a wide range of geometries. Here we will introduce the multimaterial fiber technology, its applications in engineering fields, and its adoption for the design of multifunctional and flexible neural interfaces. We will discuss examples of fiber-based neural probes tailored to the electrophysiological recording, optical neuromodulation, and delivery of drugs and genes into the rodent brain and spinal cord, as well as their emerging use for studies of nerve growth and repair.
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Affiliation(s)
- Seongjun Park
- School of Engineering, Department of Electrical Engineering and Computer Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
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103
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Beiersdorfer A, Scheller A, Kirchhoff F, Lohr C. Panglial gap junctions between astrocytes and olfactory ensheathing cells mediate transmission of Ca 2+ transients and neurovascular coupling. Glia 2019; 67:1385-1400. [PMID: 30883940 DOI: 10.1002/glia.23613] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2017] [Revised: 02/22/2019] [Accepted: 02/25/2019] [Indexed: 12/13/2022]
Abstract
Astrocytes are arranged in highly organized gap junction-coupled networks, communicating via the propagation of Ca2+ waves. Astrocytes are gap junction-coupled not only to neighboring astrocytes, but also to oligodendrocytes, forming so-called panglial syncytia. It is not known, however, whether glial cells in panglial syncytia transmit information using Ca2+ signaling. We used confocal Ca2+ imaging to study intercellular communication between astrocytes and olfactory ensheathing glial cells (OECs) in in-toto preparations of the mouse olfactory bulb. Our results demonstrate that Ca2+ transients in juxtaglomerular astrocytes, evoked by local photolysis of "caged" ATP and "caged" tACPD, led to subsequent Ca2+ responses in OECs. This transmission of Ca2+ responses from astrocytes to OECs persisted in the presence of neuronal inhibition, but was absent when gap junctional coupling was suppressed with carbenoxolone. When Ca2+ transients were directly evoked in OECs by puff application of DHPG, they resulted in delayed Ca2+ responses in juxtaglomerular astrocytes, indicating that panglial transmission of Ca2+ signals occurred in a bidirectional manner. In addition, panglial transmission of Ca2+ signals from astrocytes to OECs resulted in vasoconstriction of OEC-associated blood vessels in the olfactory nerve layer. Our results demonstrate functional transmission of Ca2+ signals between different classes of glial cells within gap junction-coupled panglial networks and the resulting regulation of blood vessel diameter in the olfactory bulb.
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Affiliation(s)
| | - Anja Scheller
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Frank Kirchhoff
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, Homburg, Germany
| | - Christian Lohr
- Division of Neurophysiology, University of Hamburg, Hamburg, Germany
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104
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Lu X, Zhang D, Shoji H, Duan C, Zhang G, Isaji T, Wang Y, Fukuda T, Gu J. Deficiency of α1,6-fucosyltransferase promotes neuroinflammation by increasing the sensitivity of glial cells to inflammatory mediators. Biochim Biophys Acta Gen Subj 2019; 1863:598-608. [DOI: 10.1016/j.bbagen.2018.12.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 12/05/2018] [Accepted: 12/13/2018] [Indexed: 10/27/2022]
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105
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Ashhad S, Narayanan R. Stores, Channels, Glue, and Trees: Active Glial and Active Dendritic Physiology. Mol Neurobiol 2019; 56:2278-2299. [PMID: 30014322 PMCID: PMC6394607 DOI: 10.1007/s12035-018-1223-5] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2017] [Accepted: 07/03/2018] [Indexed: 02/07/2023]
Abstract
Glial cells and neuronal dendrites were historically assumed to be passive structures that play only supportive physiological roles, with no active contribution to information processing in the central nervous system. Research spanning the past few decades has clearly established this assumption to be far from physiological realities. Whereas the discovery of active channel conductances and their localized plasticity was the turning point for dendritic structures, the demonstration that glial cells release transmitter molecules and communicate across the neuroglia syncytium through calcium wave propagation constituted path-breaking discoveries for glial cell physiology. An additional commonality between these two structures is the ability of calcium stores within their endoplasmic reticulum (ER) to support active propagation of calcium waves, which play crucial roles in the spatiotemporal integration of information within and across cells. Although there have been several demonstrations of regulatory roles of glial cells and dendritic structures in achieving common physiological goals such as information propagation and adaptability through plasticity, studies assessing physiological interactions between these two active structures have been few and far. This lacuna is especially striking given the strong connectivity that is known to exist between these two structures through several complex and tightly intercoupled mechanisms that also recruit their respective ER structures. In this review, we present brief overviews of the parallel literatures on active dendrites and active glial physiology and make a strong case for future studies to directly assess the strong interactions between these two structures in regulating physiology and pathophysiology of the brain.
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Affiliation(s)
- Sufyan Ashhad
- Department of Neurobiology, University of California at Los Angeles, Los Angeles, CA, 90095, USA
| | - Rishikesh Narayanan
- Cellular Neurophysiology Laboratory, Molecular Biophysics Unit, Indian Institute of Science, Bangalore, 560012, India.
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106
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You Y, Perkins A, Cisternas P, Muñoz B, Taylor X, You Y, Garringer HJ, Oblak AL, Atwood BK, Vidal R, Lasagna-Reeves CA. Tau as a mediator of neurotoxicity associated to cerebral amyloid angiopathy. Acta Neuropathol Commun 2019; 7:26. [PMID: 30808415 PMCID: PMC6390363 DOI: 10.1186/s40478-019-0680-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2018] [Accepted: 02/17/2019] [Indexed: 12/20/2022] Open
Abstract
Cerebral amyloid angiopathy (CAA) is typified by the cerebrovascular deposition of amyloid. Currently, there is no clear understanding of the mechanisms underlying the contribution of CAA to neurodegeneration. Despite the fact that CAA is highly associated with accumulation of Aβ, other types of amyloids have been shown to associate with the vasculature. Interestingly, in many cases, vascular amyloidosis is accompanied by significant tau pathology. However, the contribution of tau to neurodegeneration associated to CAA remains to be determined. We used a mouse model of Familial Danish Dementia (FDD), a neurodegenerative disease characterized by the accumulation of Danish amyloid (ADan) in the vasculature, to characterize the contribution of tau to neurodegeneration associated to CAA. We performed histological and biochemical assays to establish tau modifications associated with CAA in conjunction with cell-based and electrophysiological assays to determine the role of tau in the synaptic dysfunction associated with ADan. We demonstrated that ADan aggregates induced hyperphosphorylation and misfolding of tau. Moreover, in a mouse model for CAA, we observed tau oligomers closely associated to astrocytes in the vicinity of vascular amyloid deposits. We finally determined that the absence of tau prevents synaptic dysfunction induced by ADan oligomers. In addition to demonstrating the effect of ADan amyloid on tau misfolding, our results provide compelling evidence of the role of tau in neurodegeneration associated with ADan-CAA and suggest that decreasing tau levels could be a feasible approach for the treatment of CAA.
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107
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Gou XJ, Gao S, Chen L, Feng Q, Hu YY. A Metabolomic Study on the Intervention of Traditional Chinese Medicine Qushi Huayu Decoction on Rat Model of Fatty Liver Induced by High-Fat Diet. BIOMED RESEARCH INTERNATIONAL 2019; 2019:5920485. [PMID: 30881991 PMCID: PMC6383432 DOI: 10.1155/2019/5920485] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 01/10/2019] [Indexed: 12/23/2022]
Abstract
Qushi Huayu Decoction (QHD), an important clinically proved herbal formula, has been reported to be effective in treating fatty liver induced by high-fat diet in rats. However, the mechanism of action has not been clarified at the metabolic level. In this study, a urinary metabolomic method based on gas chromatography-mass spectrometry (GC-MS) coupled with pattern recognition analysis was performed in three groups (control, model, and QHD group), to explore the effect of QHD on fatty liver and its mechanism of action. There was obvious separation between the model group and control group, and the QHD group showed a tendency of recovering to the control group in metabolic profiles. Twelve candidate biomarkers were identified and used to explore the possible mechanism. Then, a pathway analysis was performed using MetaboAnalyst 3.0 to illustrate the pathways of therapeutic action of QHD. QHD reversed the urinary metabolite abnormalities (tryptophan, uridine, and phenylalanine, etc.). Fatty liver might be prevented by QHD through regulating the dysfunctions of phenylalanine, tyrosine, and tryptophan biosynthesis, phenylalanine metabolism, and tryptophan metabolism. This work demonstrated that metabolomics might be helpful for understanding the mechanism of action of traditional Chinese medicine for future clinical evaluation.
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Affiliation(s)
- Xiao-jun Gou
- Central Laboratory, Baoshan District Hospital of Integrated Traditional Chinese and Western Medicine of Shanghai, Shanghai University of Traditional Chinese Medicine, Shanghai 201999, China
| | - Shanshan Gao
- School of Pharmacy, Shaanxi University of Traditional Chinese Medicine, Yangxian, Shaanxi 712046, China
| | - Liang Chen
- Nantong Hospital Affiliated to Nanjing University of Chinese Medicine, Nantong, Jiangsu 226001, China
| | - Qin Feng
- Institute of Liver Disease, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
| | - Yi-yang Hu
- Institute of Liver Disease, Shuguang Hospital, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China
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108
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Potokar M, Jorgačevski J, Zorec R. Astrocytes in Flavivirus Infections. Int J Mol Sci 2019; 20:ijms20030691. [PMID: 30736273 PMCID: PMC6386967 DOI: 10.3390/ijms20030691] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2019] [Revised: 01/27/2019] [Accepted: 01/29/2019] [Indexed: 12/14/2022] Open
Abstract
Virus infections of the central nervous system (CNS) can manifest in various forms of inflammation, including that of the brain (encephalitis) and spinal cord (myelitis), all of which may have long-lasting deleterious consequences. Although the knowledge of how different viruses affect neural cells is increasing, understanding of the mechanisms by which cells respond to neurotropic viruses remains fragmented. Several virus types have the ability to infect neural tissue, and astrocytes, an abundant and heterogeneous neuroglial cell type and a key element providing CNS homeostasis, are one of the first CNS cell types to get infected. Astrocytes are morphologically closely aligned with neuronal synapses, blood vessels, and ventricle cavities, and thereby have the capacity to functionally interact with neurons and endothelial cells. In this review, we focus on the responses of astrocytes to infection by neurotropic flaviviruses, including tick-borne encephalitis virus (TBEV), Zika virus (ZIKV), West Nile virus (WNV), and Japanese encephalitis virus (JEV), which have all been confirmed to infect astrocytes and cause multiple CNS defects. Understanding these mechanisms may help design new strategies to better contain and mitigate virus- and astrocyte-dependent neuroinflammation.
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Affiliation(s)
- Maja Potokar
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
- Celica BIOMEDICAL, Tehnološki park 24, 1000 Ljubljana, Slovenia.
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
- Celica BIOMEDICAL, Tehnološki park 24, 1000 Ljubljana, Slovenia.
| | - Robert Zorec
- Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000 Ljubljana, Slovenia.
- Celica BIOMEDICAL, Tehnološki park 24, 1000 Ljubljana, Slovenia.
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109
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Preston AN, Farr JD, Tan KC, Cervasio DA, Butkus LR, Laughlin ST. Design Principles for Cationic, Astrocyte-Targeted Probes. Chembiochem 2019; 20:366-370. [PMID: 30419144 DOI: 10.1002/cbic.201800692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Indexed: 11/08/2022]
Abstract
The brain's astrocytes play key roles in normal and pathological brain processes. Targeting small molecules to astrocytes in the presence of the many other cell types in the brain will provide useful tools for their visualization and manipulation. Herein, we explore the functional consequences of synthetic modifications to a recently described astrocyte marker composed of a bright rhodamine-based fluorophore and an astrocyte-targeting moiety. We altered the nature of the targeting moiety to probe the dependence of astrocyte targeting on hydrophobicity, charge, and pKa when exposed to astrocytes and neurons isolated from the mouse cortex. We found that an overall molecular charge of +2 and a targeting moiety with a heterocyclic aromatic amine are important requirements for specific and robust astrocyte labeling. These results provide a basis for engineering astrocyte-targeted molecular tools with unique properties, including metabolite sensing or optogenetic control.
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Affiliation(s)
- Alyssa N Preston
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, 11794, USA
| | - Joshua D Farr
- Department of Chemistry, Stanford University, 450 Serra Mall, Stanford, CA, 94305, USA
| | - Kevin C Tan
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, 11794, USA
| | - Danielle A Cervasio
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, 11794, USA
| | - Lauren R Butkus
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, 11794, USA
| | - Scott T Laughlin
- Department of Chemistry, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, 11794, USA
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110
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Huang H, Wang M, Hong Y. Intrathecal administration of adrenomedullin induces mechanical allodynia and neurochemical changes in spinal cord and DRG. Neurosci Lett 2019; 690:196-201. [DOI: 10.1016/j.neulet.2018.10.037] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2018] [Revised: 10/14/2018] [Accepted: 10/16/2018] [Indexed: 12/30/2022]
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111
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The Astrocyte-Neuron Interface: An Overview on Molecular and Cellular Dynamics Controlling Formation and Maintenance of the Tripartite Synapse. Methods Mol Biol 2019; 1938:3-18. [PMID: 30617969 DOI: 10.1007/978-1-4939-9068-9_1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Astrocytes are known to provide trophic support to neurons and were originally thought to be passive space-filling cells in the brain. However, recent advances in astrocyte development and functions have highlighted their active roles in controlling brain functions by modulating synaptic transmission. A bidirectional cross talk between astrocytic processes and neuronal synapses define the concept of tripartite synapse. Any change in astrocytic structure/function influences neuronal activity which could lead to neurodevelopmental and neurodegenerative disorders. In this chapter, we briefly overview the methodologies used in deciphering the mechanisms of dynamic interplay between astrocytes and neurons.
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112
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Tsai SYA, Bendriem RM, Lee CTD. The cellular basis of fetal endoplasmic reticulum stress and oxidative stress in drug-induced neurodevelopmental deficits. Neurobiol Stress 2018; 10:100145. [PMID: 30937351 PMCID: PMC6430408 DOI: 10.1016/j.ynstr.2018.100145] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Revised: 12/02/2018] [Accepted: 12/26/2018] [Indexed: 11/30/2022] Open
Abstract
Prenatal substance exposure is a growing public health concern worldwide. Although the opioid crisis remains one of the most prevalent addiction problems in our society, abuse of cocaine, methamphetamines, and other illicit drugs, particularly amongst pregnant women, are nonetheless significant and widespread. Evidence demonstrates prenatal drug exposure can affect fetal brain development and thus can have long-lasting impact on neurobehavioral and cognitive performance later in life. In this review, we highlight research examining the most prevalent drugs of abuse and their effects on brain development with a focus on endoplasmic reticulum stress and oxidative stress signaling pathways. A thorough exploration of drug-induced cellular stress mechanisms during prenatal brain development may provide insight into therapeutic interventions to combat effects of prenatal drug exposure.
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Affiliation(s)
- S-Y A Tsai
- Integrative Neuroscience Branch, Division of Neuroscience and Behavior, National Institute on Drug Abuse, The National Institute of Health, Department of Health and Human Services, Bethesda, MD, 20892, USA
| | - Raphael M Bendriem
- Center for Neurogenetics, Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, 10021, USA
| | - Chun-Ting D Lee
- Department of Neurology, Miller School of Medicine, University of Miami, Miami, USA
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113
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Zhang Y, Wang M, Lu Q, Li Q, Lin M, Huang J, Hong Y. Inhibitory Effects of Mas-Related Gene C Receptor on Chronic Morphine-Induced Spinal Glial Activation in Rats. J Pharmacol Exp Ther 2018; 368:237-245. [DOI: 10.1124/jpet.118.252494] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2018] [Accepted: 11/20/2018] [Indexed: 12/20/2022] Open
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114
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Panossian A, Seo EJ, Efferth T. Novel molecular mechanisms for the adaptogenic effects of herbal extracts on isolated brain cells using systems biology. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2018; 50:257-284. [PMID: 30466987 DOI: 10.1016/j.phymed.2018.09.204] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Revised: 08/29/2018] [Accepted: 09/17/2018] [Indexed: 05/23/2023]
Abstract
INTRODUCTION Adaptogens are natural compounds or plant extracts that increase adaptability and survival of organisms under stress. Adaptogens stimulate cellular and organismal defense systems by activating intracellular and extracellular signaling pathways and expression of stress-activated proteins and neuropeptides. The effects adaptogens on mediators of adaptive stress response and longevity signaling pathways have been reported, but their stress-protective mechanisms are still not fully understood. AIM OF THE STUDY The aim of this study was to identify key molecular mechanisms of adaptogenic plants traditionally used to treat stress and aging-related disorders, i.e., Rhodiola rosea, Eleutherococcus senticosus, Withania somnifera, Rhaponticum carthamoides, and Bryonia alba. MATERIALS AND METHODS To investigate the underlying molecular mechanisms of adaptogens, we conducted RNA sequencing to profile gene expression alterations in T98G neuroglia cells upon treatment of adaptogens and analyzed the relevance of deregulated genes to adaptive stress-response signaling pathways using in silico pathway analysis software. RESULTS AND DISCUSSION At least 88 of the 3516 genes regulated by adaptogens were closely associated with adaptive stress response and adaptive stress-response signaling pathways (ASRSPs), including neuronal signaling related to corticotropin-releasing hormone, cAMP-mediated, protein kinase A, and CREB; pathways related to signaling involving CXCR4, melatonin, nitric oxide synthase, GP6, Gαs, MAPK, neuroinflammation, neuropathic pain, opioids, renin-angiotensin, AMPK, calcium, and synapses; and pathways associated with dendritic cell maturation and G-coupled protein receptor-mediated nutrient sensing in enteroendocrine cells. All samples tested showed significant effects on the expression of genes encoding neurohormones CRH, GNRH, UCN, G-protein-coupled and other transmembrane receptors TLR9, PRLR, CHRNE, GP1BA, PLXNA4, a ligand-dependent nuclear receptor RORA, transmembrane channels, transcription regulators FOS, FOXO6, SCX, STAT5A, ZFPM2, ZNF396, ZNF467, protein kinases MAPK10, MAPK13, MERTK, FLT1, PRKCH, ROS1, TTN), phosphatases PTPRD, PTPRR, peptidases, metabolic enzymes, a chaperone (HSPA6), and other proteins, all of which modulate numerous life processes, playing key roles in several canonical pathways involved in defense response and regulation of homeostasis in organisms. It is for the first time we report that the molecular mechanism of actions of melatonin and plant adaptogens are alike, all adaptogens tested activated the melatonin signaling pathway by acting through two G-protein-coupled membrane receptors MT1 and MT2 and upregulation of the ligand-specific nuclear receptor RORA, which plays a role in intellectual disability, neurological disorders, retinopathy, hypertension, dyslipidemia, and cancer, which are common in aging. Furthermore, melatonin activated adaptive signaling pathways and upregulated expression of UCN, GNRH1, TLR9, GP1BA, PLXNA4, CHRM4, GPR19, VIPR2, RORA, STAT5A, ZFPM2, ZNF396, FLT1, MAPK10, MERTK, PRKCH, and TTN, which were commonly regulated by all adaptogens tested. We conclude that melatonin is an adaptation hormone playing an important role in regulation of homeostasis. Adaptogens presumably worked as eustressors ("stress-vaccines") to activate the cellular adaptive system by inducing the expression of ASRSPs, which then reciprocally protected cells from damage caused by distress. Functional investigation by interactive pathways analysis demonstrated that adaptogens activated ASRSPs associated with stress-induced and aging-related disorders such as chronic inflammation, cardiovascular health, neurodegenerative cognitive impairment, metabolic disorders, and cancer. CONCLUSION This study has elucidated the genome-wide effects of several adaptogenic herbal extracts in brain cells culture. These data highlight the consistent activation of ASRSPs by adaptogens in T98G neuroglia cells. The extracts affected many genes playing key roles in modulation of adaptive homeostasis, indicating their ability to modify gene expression to prevent stress-induced and aging-related disorders. Overall, this study provides a comprehensive look at the molecular mechanisms by which adaptogens exerts stress-protective effects.
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Affiliation(s)
| | - Ean-Jeong Seo
- Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Staudinger Weg 5, Mainz 55128, Germany
| | - Thomas Efferth
- Department of Pharmaceutical Biology, Institute of Pharmacy and Biochemistry, Johannes Gutenberg University, Staudinger Weg 5, Mainz 55128, Germany.
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115
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Nikolic L, Shen W, Nobili P, Virenque A, Ulmann L, Audinat E. Blocking TNFα-driven astrocyte purinergic signaling restores normal synaptic activity during epileptogenesis. Glia 2018; 66:2673-2683. [DOI: 10.1002/glia.23519] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2018] [Revised: 07/19/2018] [Accepted: 07/20/2018] [Indexed: 12/14/2022]
Affiliation(s)
- Ljiljana Nikolic
- Neuron-glia interactions group, INSERM U1128; Paris Descartes University; Paris France
| | - Weida Shen
- Neuron-glia interactions group, INSERM U1128; Paris Descartes University; Paris France
- Department of Pharmacology; Zhejiang University City College; Hangzhou, Zhejiang China
| | - Paola Nobili
- Neuron-glia interactions group, INSERM U1128; Paris Descartes University; Paris France
| | - Anaïs Virenque
- Institute of Functional Genomics, University of Montpellier; CNRS, INSERM; Montpellier France
| | - Lauriane Ulmann
- Institute of Functional Genomics, University of Montpellier; CNRS, INSERM; Montpellier France
- LabEx Ion Channel Science and Therapeutics; Montpellier France
| | - Etienne Audinat
- Neuron-glia interactions group, INSERM U1128; Paris Descartes University; Paris France
- Institute of Functional Genomics, University of Montpellier; CNRS, INSERM; Montpellier France
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116
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New Roles for Old Glue: Astrocyte Function in Synaptic Plasticity and Neurological Disorders. Int Neurourol J 2018; 22:S106-114. [PMID: 30396259 PMCID: PMC6234728 DOI: 10.5213/inj.1836214.107] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 10/10/2018] [Indexed: 01/02/2023] Open
Abstract
Previously believed to solely play a supportive role in the central nervous system, astrocytes are now considered active players in normal brain function. Evidence in recent decades extends their contributions beyond the classically held brain glue role; it's now known that astrocytes act as a unique excitable component with functions extending into local network modulation, synaptic plasticity, and memory formation, and postinjury repair. In this review article, we highlight our growing understanding of astrocyte function and physiology, the increasing role of gliotransmitters in neuron-glia communication, and the role of astrocytes in modulating synaptic plasticity and cognitive function. Owing to the duality of both beneficial and deleterious roles attributed to astrocytes, we also discuss the implications of this new knowledge as it applies to neurological disorders including Alzheimer disease, epilepsy, and schizophrenia.
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117
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Wang X, Xuan W, Zhu ZY, Li Y, Zhu H, Zhu L, Fu DY, Yang LQ, Li PY, Yu WF. The evolving role of neuro-immune interaction in brain repair after cerebral ischemic stroke. CNS Neurosci Ther 2018; 24:1100-1114. [PMID: 30350341 DOI: 10.1111/cns.13077] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2018] [Revised: 09/23/2018] [Accepted: 09/25/2018] [Indexed: 12/13/2022] Open
Abstract
Stroke is the world's leading cause of disability with limited brain repair treatments which effectively improve long-term neurological deficits. The neuroinflammatory responses persist into the late repair phase of stroke and participate in all brain repair elements, including neurogenesis, angiogenesis, synaptogenesis, remyelination and axonal sprouting, shedding new light on post-stroke brain recovery. Resident brain glial cells, such as astrocytes not only contribute to neuroinflammation after stroke, but also secrete a wide range of trophic factors that can promote post-stroke brain repair. Alternatively, activated microglia, monocytes, and neutrophils in the innate immune system, traditionally considered as major damaging factors after stroke, have been suggested to be extensively involved in brain repair after stroke. The adaptive immune system may also have its bright side during the late regenerative phase, affecting the immune suppressive regulatory T cells and B cells. This review summarizes the recent findings in the evolving role of neuroinflammation in multiple post-stroke brain repair mechanisms and poses unanswered questions that may generate new directions for future research and give rise to novel therapeutic targets to improve stroke recovery.
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Affiliation(s)
- Xin Wang
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Wei Xuan
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Zi-Yu Zhu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Yan Li
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Hao Zhu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Ling Zhu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Dan-Yun Fu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Li-Qun Yang
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Pei-Ying Li
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Wei-Feng Yu
- Department of Anesthesiology, Renji Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
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118
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Mustaly-Kalimi S, Littlefield AM, Stutzmann GE. Calcium Signaling Deficits in Glia and Autophagic Pathways Contributing to Neurodegenerative Disease. Antioxid Redox Signal 2018; 29:1158-1175. [PMID: 29634342 DOI: 10.1089/ars.2017.7266] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
SIGNIFICANCE Numerous cellular processes and signaling mechanisms have been identified that contribute to Alzheimer's disease (AD) pathology; however, a comprehensive or unifying pathway that binds together the major disease features remains elusive. As an upstream mechanism, altered calcium (Ca2+) signaling is a common driving force for many pathophysiological events that emerge during normal aging and development of neurodegenerative disease. Recent Advances: Over the previous three decades, accumulated evidence has validated the concept that intracellular Ca2+ dysregulation is centrally involved in AD pathogenesis, including the aggregation of pathogenic β-amyloid (Aβ) and phospho-τ species, synapse loss and dysfunction, cognitive impairment, and neurotoxicity. CRITICAL ISSUES Although neuronal Ca2+ signaling within the cytosol and endoplasmic reticulum (ER) has been well studied, other critical central nervous system-resident cell types affected by aberrant Ca2+ signaling, such as astrocytes and microglia, have not been considered as thoroughly. In addition, certain intracellular Ca2+-harboring organelles have been well studied, such as the ER and mitochondria; however other critical Ca2+-regulated organelles, such as lysosomes and autophagosomes, have only more recently been investigated. In this review, we examine Ca2+ dysregulation in microglia and astrocytes, as well as key intracellular organelles important for cellular maintenance and protein handling. Ca2+ dysregulation within these non-neuronal cells and organelles is hypothesized to disrupt the effective clearance of misaggregated proteins and cellular signaling pathways needed for memory networks. FUTURE DIRECTIONS Overall, we aim to explore how these disrupted mechanisms could be involved in AD pathology and consider their role as potential therapeutic targets. Antioxid. Redox Signal. 29, 1158-1175.
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Affiliation(s)
- Sarah Mustaly-Kalimi
- 1 Department of Neuroscience, School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science , North Chicago, Illinois
| | - Alyssa M Littlefield
- 1 Department of Neuroscience, School of Graduate and Postdoctoral Studies, Rosalind Franklin University of Medicine and Science , North Chicago, Illinois
| | - Grace E Stutzmann
- 2 Department of Neuroscience, The Chicago Medical School, Rosalind Franklin University of Medicine and Science , North Chicago, Illinois
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119
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Deemyad T, Lüthi J, Spruston N. Astrocytes integrate and drive action potential firing in inhibitory subnetworks. Nat Commun 2018; 9:4336. [PMID: 30337521 PMCID: PMC6194108 DOI: 10.1038/s41467-018-06338-3] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 08/27/2018] [Indexed: 12/29/2022] Open
Abstract
Many brain functions depend on the ability of neural networks to temporally integrate transient inputs to produce sustained discharges. This can occur through cell-autonomous mechanisms in individual neurons and through reverberating activity in recurrently connected neural networks. We report a third mechanism involving temporal integration of neural activity by a network of astrocytes. Previously, we showed that some types of interneurons can generate long-lasting trains of action potentials (barrage firing) following repeated depolarizing stimuli. Here we show that calcium signaling in an astrocytic network correlates with barrage firing; that active depolarization of astrocyte networks by chemical or optogenetic stimulation enhances; and that chelating internal calcium, inhibiting release from internal stores, or inhibiting GABA transporters or metabotropic glutamate receptors inhibits barrage firing. Thus, networks of astrocytes influence the spatiotemporal dynamics of neural networks by directly integrating neural activity and driving barrages of action potentials in some populations of inhibitory interneurons. Specific types of inhibitory neurons exhibit prolonged, high-frequency barrages of action potentials. Here, the authors show that astrocytes might mediate such barrage firing.
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Affiliation(s)
- Tara Deemyad
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20147, USA.,Department of Neurobiology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, 15213, USA
| | - Joel Lüthi
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20147, USA.,Institute of Molecular Life Sciences, University of Zürich, Zürich, 8057, Switzerland
| | - Nelson Spruston
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA, 20147, USA.
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120
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Sun L, Zhang Y, Liu E, Ma Q, Anatol M, Han H, Yan J. The roles of astrocyte in the brain pathologies following ischemic stroke. Brain Inj 2018; 33:712-716. [PMID: 30335519 DOI: 10.1080/02699052.2018.1531311] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Aim: In this work, we systematically explored the physiological functions of astrocytes and their roles following ischemic stroke, additionally, the potential therapy strategy targeting the astrocytes was also discussed. Methods: This work searched the PubMed database (including MEDLINE) until 14 Feb 2018, and furthermore, the studies were identified through cross-referencing and by consulting the experts in this field. Results: This study indicated that the astrocytes can not only play harmful roles following ischemic stroke through release of inflammatory factors and formation of glial scar but also have protective effects through quenching glutamate excitotoxicity and maintaining the clearance function of glymphatic system in brain. Conclusion: Owing to their important roles in physiological functions of brain and in the pathological conditions following ischemic stroke, the astrocytes might be a potential but promising therapeutic target for treating the ischemic stroke in the future.
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Affiliation(s)
- Linlin Sun
- a Department of Anatomy and Histology, School of Basic Medical Sciences , Peking University , Beijing , China
| | - Yixuan Zhang
- a Department of Anatomy and Histology, School of Basic Medical Sciences , Peking University , Beijing , China
| | - E Liu
- a Department of Anatomy and Histology, School of Basic Medical Sciences , Peking University , Beijing , China
| | - Qingyi Ma
- b Center for Perinatal Biology, School of Medicine , Loma Linda University , Loma Linda , USA
| | - Manaenko Anatol
- c Departments of Neurology , University of Erlangen-Nuremberg , Erlangen , Germany
| | - Hongbin Han
- d Beijing Key Lab of Magnetic Resonance Imaging Technology , Beijing , China
| | - Junhao Yan
- a Department of Anatomy and Histology, School of Basic Medical Sciences , Peking University , Beijing , China.,d Beijing Key Lab of Magnetic Resonance Imaging Technology , Beijing , China
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122
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SheikhBahaei S, Morris B, Collina J, Anjum S, Znati S, Gamarra J, Zhang R, Gourine AV, Smith JC. Morphometric analysis of astrocytes in brainstem respiratory regions. J Comp Neurol 2018; 526:2032-2047. [PMID: 29888789 PMCID: PMC6158060 DOI: 10.1002/cne.24472] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 05/07/2018] [Accepted: 05/13/2018] [Indexed: 12/30/2022]
Abstract
Astrocytes, the most abundant and structurally complex glial cells of the central nervous system, are proposed to play an important role in modulating the activities of neuronal networks, including respiratory rhythm‐generating circuits of the preBötzinger complex (preBötC) located in the ventrolateral medulla of the brainstem. However, structural properties of astrocytes residing within different brainstem regions are unknown. In this study astrocytes in the preBötC, an intermediate reticular formation (IRF) region with respiratory‐related function, and a region of the nucleus tractus solitarius (NTS) in adult rats were reconstructed and their morphological features were compared. Detailed morphological analysis revealed that preBötC astrocytes are structurally more complex than those residing within the functionally distinct neighboring IRF region, or the NTS, located at the dorsal aspect of the medulla oblongata. Structural analyses of the brainstem microvasculature indicated no significant regional differences in vascular properties. We hypothesize that high morphological complexity of preBötC astrocytes reflects their functional role in providing structural/metabolic support and modulation of the key neuronal circuits essential for breathing, as well as constraints imposed by arrangements of associated neurons and/or other local structural features of the brainstem parenchyma.
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Affiliation(s)
- Shahriar SheikhBahaei
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland.,Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London, UK
| | - Brian Morris
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
| | - Jared Collina
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
| | - Sommer Anjum
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
| | - Sami Znati
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
| | - Julio Gamarra
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
| | - Ruli Zhang
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
| | - Alexander V Gourine
- Centre for Cardiovascular and Metabolic Neuroscience, Department of Neuroscience, Physiology, and Pharmacology, University College London, London, UK
| | - Jeffrey C Smith
- Cellular and Systems Neurobiology Section, National Institute of Neurological Disorders and Stroke (NINDS) National Institutes of Health (NIH), Bethesda, Maryland
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123
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Song SY, Chae M, Yu JH, Lee MY, Pyo S, Shin YK, Baek A, Park JW, Park ES, Choi JY, Cho SR. Environmental Enrichment Upregulates Striatal Synaptic Vesicle-Associated Proteins and Improves Motor Function. Front Neurol 2018; 9:465. [PMID: 30061854 PMCID: PMC6054977 DOI: 10.3389/fneur.2018.00465] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Accepted: 05/31/2018] [Indexed: 11/13/2022] Open
Abstract
Environmental enrichment (EE) is a therapeutic paradigm that consists of complex combinations of physical, cognitive, and social stimuli. The mechanisms underlying EE-mediated synaptic plasticity have yet to be fully elucidated. In this study, we investigated the effects of EE on synaptic vesicle-associated proteins and whether the expression of these proteins is related to behavioral outcomes. A total of 44 CD-1® (ICR) mice aged 6 weeks were randomly assigned to either standard cages or EE (N = 22 each). Rotarod and ladder walking tests were then performed to evaluate motor function. To identify the molecular mechanisms underlying the effects of EE, we assessed differentially expressed proteins (DEPs) in the striatum by proteomic analysis. Quantitative real-time polymerase chain reaction (qRT-PCR), western blot, and immunohistochemistry were conducted to validate the expressions of these proteins. In the behavioral assessment, EE significantly enhanced performance on the rotarod and ladder walking tests. A total of 116 DEPs (54 upregulated and 62 downregulated proteins) were identified in mice exposed to EE. Gene ontology (GO) analysis demonstrated that the upregulated proteins in EE mice were primarily related to biological processes of synaptic vesicle transport and exocytosis. The GO terms for these biological processes commonly included Synaptic vesicle glycoprotein 2B (SV2B), Rabphilin-3A, and Piccolo. The qRT-PCR and western blot analyses revealed that EE increased the expression of SV2B, Rabphilin-3A and Piccolo in the striatum compared to the control group. Immunohistochemistry showed that the density of Piccolo in the vicinity of the subventricular zone was significantly increased in the EE mice compared with control mice. In conclusion, EE upregulates proteins associated with synaptic vesicle transport and exocytosis such as SV2B, Rabphilin-3A and Piccolo in the striatum. These upregulated proteins may be responsible for locomotor performance improvement, as shown in rotarod and ladder walking tests. Elucidation of these changes in synaptic protein expression provides new insights into the mechanism and potential role of EE.
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Affiliation(s)
- Suk-Young Song
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Graduate Program of NanoScience and Technology, Yonsei University, Seoul, South Korea
| | - Minji Chae
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Rehabilitation Institute of Neuromuscular Disease, Yonsei University College of Medicine, Seoul, South Korea
| | - Ji Hea Yu
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Min Young Lee
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Soonil Pyo
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, South Korea
| | - Yoon-Kyum Shin
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, South Korea
| | - Ahreum Baek
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Department of Rehabilitation Medicine, Yonsei University Wonju College of Medicine, Wonju, South Korea
| | - Jung-Won Park
- Department of Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Eun Sook Park
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea
| | - Ja Young Choi
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Department of Rehabilitation Medicine, Eulji University School of Medicine, Daejeon, South Korea
| | - Sung-Rae Cho
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, Seoul, South Korea.,Graduate Program of NanoScience and Technology, Yonsei University, Seoul, South Korea.,Rehabilitation Institute of Neuromuscular Disease, Yonsei University College of Medicine, Seoul, South Korea.,Brain Korea 21 PLUS Project for Medical Science, Yonsei University, Seoul, South Korea
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124
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A New Computational Model for Astrocytes and Their Role in Biologically Realistic Neural Networks. COMPUTATIONAL INTELLIGENCE AND NEUROSCIENCE 2018; 2018:3689487. [PMID: 30073021 PMCID: PMC6057343 DOI: 10.1155/2018/3689487] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 06/14/2018] [Indexed: 12/03/2022]
Abstract
Recent studies in neuroscience show that astrocytes alongside neurons participate in modulating synapses. It led to the new concept of “tripartite synapse”, which means that a synapse consists of three parts: presynaptic neuron, postsynaptic neuron, and neighboring astrocytes. However, it is still unclear what role is played by the astrocytes in the tripartite synapse. Detailed biocomputational modeling may help generate testable hypotheses. In this article, we aim to study the role of astrocytes in synaptic plasticity by exploring whether tripartite synapses are capable of improving the performance of a neural network. To achieve this goal, we developed a computational model of astrocytes based on the Izhikevich simple model of neurons. Next, two neural networks were implemented. The first network was only composed of neurons and had standard bipartite synapses. The second network included both neurons and astrocytes and had tripartite synapses. We used reinforcement learning and tested the networks on categorizing random stimuli. The results show that tripartite synapses are able to improve the performance of a neural network and lead to higher accuracy in a classification task. However, the bipartite network was more robust to noise. This research provides computational evidence to begin elucidating the possible beneficial role of astrocytes in synaptic plasticity and performance of a neural network.
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125
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Pamphlett R, Kum Jew S. Inorganic mercury in human astrocytes, oligodendrocytes, corticomotoneurons and the locus ceruleus: implications for multiple sclerosis, neurodegenerative disorders and gliomas. Biometals 2018; 31:807-819. [PMID: 29959651 PMCID: PMC6133182 DOI: 10.1007/s10534-018-0124-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2018] [Accepted: 06/21/2018] [Indexed: 12/11/2022]
Abstract
Neurotoxic metals have been implicated in the pathogenesis of multiple sclerosis, neurodegenerative disorders and brain tumours but studies of the location of heavy metals in human brains are rare. In a man who injected himself with metallic mercury the cellular location of mercury in his brain was studied after 5 months of continuous exposure to inorganic mercury arising from metallic mercury deposits in his organs. Paraffin sections from the primary motor and sensory cortices and the locus ceruleus in the pons were stained with autometallography to detect inorganic mercury and combined with glial fibrillary acidic protein immunohistochemistry to identify astrocytes. Inorganic mercury was found in grey matter subpial, interlaminar, protoplasmic and varicose astrocytes, white matter fibrous astrocytes, grey but not white matter oligodendrocytes, corticomotoneurons and some locus ceruleus neurons. In summary, inorganic mercury is taken up by five types of human brain astrocytes, as well as by cortical oligodendrocytes, corticomotoneurons and locus ceruleus neurons. Mercury can induce oxidative stress, stimulate autoimmunity and damage DNA, mitochondria and lipid membranes, so its location in these CNS cells suggests it could play a role in the pathogenesis of multiple sclerosis, neurodegenerative conditions such as Alzheimer's disease and amyotrophic lateral sclerosis, and glial tumours.
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Affiliation(s)
- Roger Pamphlett
- Discipline of Pathology, The University of Sydney, Camperdown, Australia. .,Discipline of Pathology, Brain and Mind Centre, The University of Sydney and Department of Neuropathology, Royal Prince Alfred Hospital, 94 Mallett St, Camperdown, NSW, 2050, Australia.
| | - Stephen Kum Jew
- Discipline of Pathology, The University of Sydney, Camperdown, Australia
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126
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Astrocytic Activation Generates De Novo Neuronal Potentiation and Memory Enhancement. Cell 2018; 174:59-71.e14. [PMID: 29804835 DOI: 10.1016/j.cell.2018.05.002] [Citation(s) in RCA: 336] [Impact Index Per Article: 56.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2017] [Revised: 01/31/2018] [Accepted: 04/27/2018] [Indexed: 12/20/2022]
Abstract
Astrocytes respond to neuronal activity and were shown to be necessary for plasticity and memory. To test whether astrocytic activity is also sufficient to generate synaptic potentiation and enhance memory, we expressed the Gq-coupled receptor hM3Dq in CA1 astrocytes, allowing their activation by a designer drug. We discovered that astrocytic activation is not only necessary for synaptic plasticity, but also sufficient to induce NMDA-dependent de novo long-term potentiation in the hippocampus that persisted after astrocytic activation ceased. In vivo, astrocytic activation enhanced memory allocation; i.e., it increased neuronal activity in a task-specific way only when coupled with learning, but not in home-caged mice. Furthermore, astrocytic activation using either a chemogenetic or an optogenetic tool during acquisition resulted in memory recall enhancement on the following day. Conversely, directly increasing neuronal activity resulted in dramatic memory impairment. Our findings that astrocytes induce plasticity and enhance memory may have important clinical implications for cognitive augmentation treatments.
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127
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Gaburro J, Bhatti A, Sundaramoorthy V, Dearnley M, Green D, Nahavandi S, Paradkar PN, Duchemin JB. Zika virus-induced hyper excitation precedes death of mouse primary neuron. Virol J 2018; 15:79. [PMID: 29703263 PMCID: PMC5922018 DOI: 10.1186/s12985-018-0989-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Accepted: 04/19/2018] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND Zika virus infection in new born is linked to congenital syndromes, especially microcephaly. Studies have shown that these neuropathies are the result of significant death of neuronal progenitor cells in the central nervous system of the embryo, targeted by the virus. Although cell death via apoptosis is well acknowledged, little is known about possible pathogenic cellular mechanisms triggering cell death in neurons. METHODS We used in vitro embryonic mouse primary neuron cultures to study possible upstream cellular mechanisms of cell death. Neuronal networks were grown on microelectrode array and electrical activity was recorded at different times post Zika virus infection. In addition to this method, we used confocal microscopy and Q-PCR techniques to observe morphological and molecular changes after infection. RESULTS Zika virus infection of mouse primary neurons triggers an early spiking excitation of neuron cultures, followed by dramatic loss of this activity. Using NMDA receptor antagonist, we show that this excitotoxicity mechanism, likely via glutamate, could also contribute to the observed nervous system defects in human embryos and could open new perspective regarding the causes of adult neuropathies. CONCLUSIONS This model of excitotoxicity, in the context of neurotropic virus infection, highlights the significance of neuronal activity recording with microelectrode array and possibility of more than one lethal mechanism after Zika virus infection in the nervous system.
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Affiliation(s)
- Julie Gaburro
- CSIRO Health and Biosecurity, Australian Animal Health Laboratory, Geelong, Australia
- Institute for Intelligent Systems Research and Innovation (IISRI), Deakin University, Geelong, Australia
| | - Asim Bhatti
- Institute for Intelligent Systems Research and Innovation (IISRI), Deakin University, Geelong, Australia
| | - Vinod Sundaramoorthy
- CSIRO Health and Biosecurity, Australian Animal Health Laboratory, Geelong, Australia
| | - Megan Dearnley
- CSIRO Health and Biosecurity, Australian Animal Health Laboratory, Geelong, Australia
| | - Diane Green
- CSIRO Health and Biosecurity, Australian Animal Health Laboratory, Geelong, Australia
| | - Saeid Nahavandi
- Institute for Intelligent Systems Research and Innovation (IISRI), Deakin University, Geelong, Australia
| | - Prasad N Paradkar
- CSIRO Health and Biosecurity, Australian Animal Health Laboratory, Geelong, Australia
| | - Jean-Bernard Duchemin
- CSIRO Health and Biosecurity, Australian Animal Health Laboratory, Geelong, Australia.
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Abstract
The schwann cells of the peripheral nervous system are indispensable for the formation, maintenance, and modulation of synapses over the life cycle. They not only recognize neuron-glia signaling molecules, but also secrete gliotransmitters. Through these processes, they regulate neuronal excitability and thus the release of neurotransmitters from the nerve terminal at the neuromuscular junction. Gliotransmitters strongly affect nerve communication, and their secretion is mainly triggered by synchronized Ca2+ signaling, implicating Ca2+ waves in synapse function. Reciprocally, neurotransmitters released during synaptic activity can evoke increases in intracellular Ca2+ levels. A reconsideration of the interplay between the two main types of cells in the nervous system is due, as the concept of nervous system activity comprising only neuron-neuron and neuron-muscle action has become untenable. A more precise understanding of the roles of schwann cells in nerve-muscle signaling is required.
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Affiliation(s)
- Sujin Hyung
- Department of Mechanical and Aerospace Engineering, Seoul National University, San 56-1, Shilim-dong, Gwanak-gu, Seoul, 08826, Korea
- BK21 Plus Transformative Training Program for Creative Mechanical and Aerospace Engineers, Seoul National University, San 56-1, Shilim-dong, Gwanak-gu, Seoul, 08826, Korea
| | - Kyuhwan Jung
- Graduate Program of Nano Science and Technology, Graduate School of Yonsei University, 50-1 Yonsei Ro, Seodaemun-gu, Seoul, 03722, Korea
| | - Sung-Rae Cho
- Graduate Program of Nano Science and Technology, Graduate School of Yonsei University, 50-1 Yonsei Ro, Seodaemun-gu, Seoul, 03722, Korea
- Department and Research Institute of Rehabilitation Medicine, Yonsei University College of Medicine, 50-1 Yonsei Ro, Seodaemun-gu, Seoul, 03722, Korea
| | - Noo Li Jeon
- Department of Mechanical and Aerospace Engineering, Seoul National University, San 56-1, Shilim-dong, Gwanak-gu, Seoul, 08826, Korea
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129
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Zorec R, Parpura V, Verkhratsky A. Preventing neurodegeneration by adrenergic astroglial excitation. FEBS J 2018; 285:3645-3656. [PMID: 29630772 DOI: 10.1111/febs.14456] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2018] [Revised: 03/17/2018] [Accepted: 03/28/2018] [Indexed: 01/22/2023]
Abstract
Impairment of the main noradrenergic nucleus of the human brain, the locus coeruleus (LC), which has been discovered in 1784, represents one of defining factors of neurodegenerative diseases progression. Projections of LC neurons release noradrenaline/norepinephrine (NA), which stimulates astrocytes, homeostatic neuroglial cells enriched with adrenergic receptors. There is a direct correlation between the reduction in noradrenergic innervations and cognitive decline associated with ageing and neurodegenerative diseases. It is, therefore, hypothesized that the resilience of LC neurons to degeneration influences the neural reserve that in turn determines cognitive decline. Deficits in the noradrenergic innervation of the brain might be reversed or restrained by increasing the activity of existing LC neurons, transplanting noradrenergic neurons, and/or using drugs that mimic the activity of NA on astroglia. Here, these strategies are discussed with the aim to understand how astrocytes integrate neuronal network activity in the brain information processing in health and disease.
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Affiliation(s)
- Robert Zorec
- Laboratory of Neuroendocrinology and Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Slovenia.,Celica, BIOMEDICAL, Ljubljana, Slovenia
| | - Vladimir Parpura
- Department of Neurobiology, Civitan International Research Center and Center for Glial Biology in Medicine, Evelyn F. McKnight Brain Institute, Atomic Force Microscopy & Nanotechnology Laboratories, University of Alabama, Birmingham, AL, USA
| | - Alexei Verkhratsky
- Laboratory of Neuroendocrinology and Molecular Cell Physiology, Institute of Pathophysiology, University of Ljubljana, Slovenia.,Celica, BIOMEDICAL, Ljubljana, Slovenia.,Faculty of Biology, Medicine and Health, The University of Manchester, UK.,Achucarro Center for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain.,Department of Neurosciences, University of the Basque Country UPV/EHU and CIBERNED, Leioa, Spain
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Ma J, Qi X, Yang C, Pan R, Wang S, Wu J, Huang L, Chen H, Cheng J, Wu R, Liao Y, Mao L, Wang FC, Wu Z, An JX, Wang Y, Zhang X, Zhang C, Yuan Z. Calhm2 governs astrocytic ATP releasing in the development of depression-like behaviors. Mol Psychiatry 2018; 23:883-891. [PMID: 29180673 DOI: 10.1038/mp.2017.229] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2016] [Revised: 07/14/2017] [Accepted: 07/17/2017] [Indexed: 12/13/2022]
Abstract
Extracellular ATP is a widespread cell-to-cell signaling molecule in the brain, where it functions as a neuromodulator by activating glia and neurons. Although ATP exerts multiple effects on synaptic plasticity and neuro-glia interactions, as well as in mood disorders, the source and regulation of ATP release remain to be elaborated. Here, we define Calhm2 as an ATP-releasing channel protein based on in vitro and in vivo models. Conventional knockout and conditional astrocyte knockout of Calhm2 both lead to significantly reduced ATP concentrations, loss of hippocampal spine number, neural dysfunction and depression-like behaviors in mice, which can be significantly rescued by ATP replenishment. Our findings identify Calhm2 as a critical ATP-releasing channel that modulates neural activity and as a potential risk factor of depression.
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Affiliation(s)
- J Ma
- The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing, China.,State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China.,Department of Anesthesiology, Pain Medicine & Critical Care Medicine, Aviation General Hospital of China Medical University, Beijing, China
| | - X Qi
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - C Yang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing, China
| | - R Pan
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - S Wang
- The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - J Wu
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - L Huang
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - H Chen
- State Key Laboratory of Brain and Cognitive Sciences, Institute of Biophysics, Chinese Academy of Sciences, Beijing, China
| | - J Cheng
- The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - R Wu
- The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Y Liao
- The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - L Mao
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, the Chinese Academy of Sciences, Beijing, China
| | - F C Wang
- National Institute of Biological Sciences, Beijing, China
| | - Z Wu
- Department of Neurology and Research Center of Neurology in Second Affiliated Hosipital, and the Collaborative Innovation Center for Brain Science, Zhejiang University School of Medicine, Hanzhou, Zhejiang, China
| | - J X An
- Department of Anesthesiology, Pain Medicine & Critical Care Medicine, Aviation General Hospital of China Medical University, Beijing, China
| | - Y Wang
- Neuroscience Research Institute and Department of Neurobiology, School of Basic Medical Sciences, Key Laboratory for Neuroscience, Ministry of Education/National Health and Family Planning Commission, Peking University, Beijing, China
| | - X Zhang
- University of Ottawa Institute of Mental Health Research, Departments of Psychiatry and Cellular & Molecular Medicine, University of Ottawa, Ottawa, ON, Canada
| | - C Zhang
- State Key Laboratory of Membrane Biology, School of Life Sciences, Peking University, Beijing, China
| | - Z Yuan
- The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing, China.,Center of Alzheimer's Disease, Beijing Institute for Brain Disorders, Beijing, China
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131
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Tian B, Xu S, Rogers JA, Cestellos-Blanco S, Yang P, Carvalho-de-Souza JL, Bezanilla F, Liu J, Bao Z, Hjort M, Cao Y, Melosh N, Lanzani G, Benfenati F, Galli G, Gygi F, Kautz R, Gorodetsky AA, Kim SS, Lu TK, Anikeeva P, Cifra M, Krivosudský O, Havelka D, Jiang Y. Roadmap on semiconductor-cell biointerfaces. Phys Biol 2018; 15:031002. [PMID: 29205173 PMCID: PMC6599646 DOI: 10.1088/1478-3975/aa9f34] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
This roadmap outlines the role semiconductor-based materials play in understanding the complex biophysical dynamics at multiple length scales, as well as the design and implementation of next-generation electronic, optoelectronic, and mechanical devices for biointerfaces. The roadmap emphasizes the advantages of semiconductor building blocks in interfacing, monitoring, and manipulating the activity of biological components, and discusses the possibility of using active semiconductor-cell interfaces for discovering new signaling processes in the biological world.
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Affiliation(s)
- Bozhi Tian
- Department of Chemistry, University of Chicago, Chicago, IL 60637, United States of America
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132
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Svobodova I, Bhattaracharya A, Ivetic M, Bendova Z, Zemkova H. Circadian ATP Release in Organotypic Cultures of the Rat Suprachiasmatic Nucleus Is Dependent on P2X7 and P2Y Receptors. Front Pharmacol 2018; 9:192. [PMID: 29559915 PMCID: PMC5845546 DOI: 10.3389/fphar.2018.00192] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 02/20/2018] [Indexed: 01/22/2023] Open
Abstract
The circadian rhythms in physiological and behavioral functions are driven by a pacemaker located in the suprachiasmatic nucleus (SCN). The rhythms continue in constant darkness and depend on cell-cell communication between neurons and glia. The SCN astrocytes generate also a circadian rhythm in extracellular adenosine 5′-triphosphate (ATP) accumulation, but molecular mechanisms that regulate ATP release are poorly understood. Here, we tested the hypothesis that ATP is released via the plasma membrane purinergic P2X7 receptors (P2X7Rs) and P2Y receptors (P2YRs) which have been previously shown to be expressed in the SCN tissue at transcriptional level. We have investigated this hypothesis using SCN organotypic cultures, primary cultures of SCN astrocytes, ATP bioluminescent assays, immunohistochemistry, patch-clamping, and calcium imaging. We found that extracellular ATP accumulation in organotypic cultures followed a circadian rhythm, with a peak between 24:00 and 04:00 h, and the trough at ~12:00 h. ATP rhythm was inhibited by application of AZ10606120, A438079, and BBG, specific blockers of P2X7R, and potentiated by GW791343, a positive allosteric modulator of this receptor. Double-immunohistochemical staining revealed high expression of the P2X7R protein in astrocytes of SCN slices. PPADS, a non-specific P2 antagonist, and MRS2179, specific P2Y1R antagonist, also abolished ATP rhythm, whereas the specific P2X4R blocker 5-BDBD was not effective. The pannexin-1 hemichannel blocker carbenoxolone displayed a partial inhibitory effect. The P2Y1R agonist MRS2365, and the P2Y2R agonist MRS2768 potentiated ATP release in organotypic cultures and increase intracellular Ca2+ level in cultured astrocytes. Thus, SCN utilizes multiple purinergic receptor systems and pannexin-1 hemichannels to release ATP.
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Affiliation(s)
- Irena Svobodova
- Department of Cellular and Molecular Neuroendocrinology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Anirban Bhattaracharya
- Department of Cellular and Molecular Neuroendocrinology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Milorad Ivetic
- Department of Cellular and Molecular Neuroendocrinology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
| | - Zdenka Bendova
- Department of Physiology, Faculty of Science, Charles University, Prague, Czechia
| | - Hana Zemkova
- Department of Cellular and Molecular Neuroendocrinology, Institute of Physiology of the Czech Academy of Sciences, Prague, Czechia
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133
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Das V, Kc R, Li X, Varma D, Qiu S, Kroin JS, Forsyth CB, Keshavarzian A, van Wijnen AJ, Park TJ, Stein GS, O-Sullivan I, Burris TP, Im HJ. Pharmacological targeting of the mammalian clock reveals a novel analgesic for osteoarthritis-induced pain. Gene 2018; 655:1-12. [PMID: 29474860 DOI: 10.1016/j.gene.2018.02.048] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Accepted: 02/19/2018] [Indexed: 01/02/2023]
Abstract
Environmental disruption of the circadian rhythm is linked with increased pain due to osteoarthritis (OA). We aimed to characterize the role of the clock gene in OA-induced pain more systemically using both genetic and pharmacological approaches. Genetically modified mice, (bmal1f/fNav1.8CreERT mice), generated by deleting the critical clock gene, bmal1, from Nav1.8 sensory neurons, were resistant to the development of mechanical hyperalgesia associated with OA induced by partial medial meniscectomy (PMM) of the knee. In wild-type mice, induction of OA by PMM surgery led to a substantial increase in BMAL1 expression in DRG neurons. Interestingly, pharmacological activation of the REV-ERB (a negative regulator of bmal1 transcription) with SR9009 resulted in reduction of BMAL1 expression, and a significant decrease in mechanical hyperalgesia associated with OA. Cartilage degeneration was also significantly reduced in mice treated with the REV-ERB agonist SR9009. Based on these data, we also assessed the effect of pharmacological activation of REV-ERB using a model of environmental circadian disruption with its associated mechanical hyperalgesia, and noted that SR9009 was an effective analgesic in this model as well. Our data clearly demonstrate that genetic disruption of the molecular clock, via deletion of bmal1 in the sensory neurons of the DRG, decreases pain in a model of OA. Furthermore, pharmacological activation of REV-ERB leading to suppression of BMAL1 expression may be an effective method for treating OA-related pain, as well as to reduce joint damage associated with this disease.
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Affiliation(s)
- Vaskar Das
- Department of Anesthesiology, Rush University Medical Center, Chicago, IL, USA; Department of Biochemistry, Rush University Medical Center, Chicago, IL, USA
| | - Ranjan Kc
- Department of Biochemistry, Rush University Medical Center, Chicago, IL, USA
| | - Xin Li
- Department of Biochemistry, Rush University Medical Center, Chicago, IL, USA
| | - Disha Varma
- Department of Biochemistry, Rush University Medical Center, Chicago, IL, USA
| | - Sujun Qiu
- Department of Biochemistry, Rush University Medical Center, Chicago, IL, USA; Department of Orthopedics, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Jeffrey S Kroin
- Department of Anesthesiology, Rush University Medical Center, Chicago, IL, USA
| | - Christopher B Forsyth
- Department of Internal Medicine Division of Digestive Diseases and Nutrition, Rush University Medical Center, Chicago, IL, USA
| | - Ali Keshavarzian
- Department of Internal Medicine Division of Digestive Diseases and Nutrition, Rush University Medical Center, Chicago, IL, USA
| | | | - Thomas J Park
- Department of Biological Science, University of Illinois at Chicago, IL, USA
| | - Gary S Stein
- Department of Biochemistry, University of Vermont College of Medicine, Burlington, VT, USA
| | - Insug O-Sullivan
- Department of Medicine, University of Illinois at Chicago, IL, USA
| | - Thomas P Burris
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, St Louis, MO, USA.
| | - Hee-Jeong Im
- Department of Bioengineering, University of Illinois at Chicago, IL, USA; Jesse Brown Veterans Affairs Medical Center (JBVAMC), Chicago, IL, USA.
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134
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Tatsumi K, Isonishi A, Yamasaki M, Kawabe Y, Morita-Takemura S, Nakahara K, Terada Y, Shinjo T, Okuda H, Tanaka T, Wanaka A. Olig2-Lineage Astrocytes: A Distinct Subtype of Astrocytes That Differs from GFAP Astrocytes. Front Neuroanat 2018; 12:8. [PMID: 29497365 PMCID: PMC5819569 DOI: 10.3389/fnana.2018.00008] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/19/2018] [Indexed: 12/22/2022] Open
Abstract
Astrocytes are the most abundant glia cell type in the central nervous system (CNS), and are known to constitute heterogeneous populations that differ in their morphology, gene expression and function. Although glial fibrillary acidic protein (GFAP) is the cardinal cytological marker of CNS astrocytes, GFAP-negative astrocytes can easily be found in the adult CNS. Astrocytes are also allocated to spatially distinct regional domains during development. This regional heterogeneity suggests that they help to coordinate post-natal neural circuit formation and thereby to regulate eventual neuronal activity. Here, during lineage-tracing studies of cells expressing Olig2 using Olig2CreER; Rosa-CAG-LSL-eNpHR3.0-EYFP transgenic mice, we found Olig2-lineage mature astrocytes in the adult forebrain. Long-term administration of tamoxifen resulted in sufficient recombinant induction, and Olig2-lineage cells were found to be preferentially clustered in some adult brain nuclei. We then made distribution map of Olig2-lineage astrocytes in the adult mouse brain, and further compared the map with the distribution of GFAP-positive astrocytes visualized in GFAPCre; Rosa-CAG-LSL-eNpHR3.0-EYFP mice. Brain regions rich in Olig2-lineage astrocytes (e.g., basal forebrain, thalamic nuclei, and deep cerebellar nuclei) tended to lack GFAP-positive astrocytes, and vice versa. Even within a single brain nucleus, Olig2-lineage astrocytes and GFAP astrocytes frequently occupied mutually exclusive territories. These findings strongly suggest that there is a subpopulation of astrocytes (Olig2-lineage astrocytes) in the adult brain, and that it differs from GFAP-positive astrocytes in its distribution pattern and perhaps also in its function. Interestingly, the brain nuclei rich in Olig2-lineage astrocytes strongly expressed GABA-transporter 3 in astrocytes and vesicular GABA transporter in neurons, suggesting that Olig2-lineage astrocytes are involved in inhibitory neuronal transmission.
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Affiliation(s)
- Kouko Tatsumi
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Ayami Isonishi
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Miwako Yamasaki
- Department of Anatomy, Hokkaido University Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Yoshie Kawabe
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Shoko Morita-Takemura
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Kazuki Nakahara
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Yuki Terada
- Department of Anesthesiology, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Takeaki Shinjo
- Department of Anesthesiology, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Hiroaki Okuda
- Department of Functional Anatomy, Graduate School of Medical Science, Kanazawa University, Kanazawa, Japan
| | - Tatsuhide Tanaka
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
| | - Akio Wanaka
- Department of Anatomy and Neuroscience, Faculty of Medicine, Nara Medical University, Kashihara, Japan
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135
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Chi-Castañeda D, Ortega A. Glial Cells in the Genesis and Regulation of Circadian Rhythms. Front Physiol 2018; 9:88. [PMID: 29483880 PMCID: PMC5816069 DOI: 10.3389/fphys.2018.00088] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/26/2018] [Indexed: 12/26/2022] Open
Abstract
Circadian rhythms are biological oscillations with a period of ~24 h. These rhythms are orchestrated by a circadian timekeeper in the suprachiasmatic nucleus of the hypothalamus, the circadian "master clock," which exactly adjusts clock outputs to solar time via photic synchronization. At the molecular level, circadian rhythms are generated by the interaction of positive and negative feedback loops of transcriptional and translational processes of the so-called "clock genes." A large number of clock genes encode numerous proteins that regulate their own transcription and that of other genes, collectively known as "clock-controlled genes." In addition to the sleep/wake cycle, many cellular processes are regulated by circadian rhythms, including synaptic plasticity in which an exquisite interplay between neurons and glial cells takes place. In particular, there is compelling evidence suggesting that glial cells participate in and regulate synaptic plasticity in a circadian fashion, possibly representing the missing cellular and physiological link between circadian rhythms with learning and cognition processes. Here we review recent studies in support of this hypothesis, focusing on the interplay between glial cells, synaptic plasticity, and circadian rhythmogenesis.
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Affiliation(s)
- Donají Chi-Castañeda
- Laboratorio de Neurotoxicología, Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de Mexico, Mexico.,Soluciones para un México Verde S.A. de C.V., Ciudad de Mexico, Mexico
| | - Arturo Ortega
- Laboratorio de Neurotoxicología, Departamento de Toxicología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Ciudad de Mexico, Mexico
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136
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Koizumi S, Hirayama Y, Morizawa YM. New roles of reactive astrocytes in the brain; an organizer of cerebral ischemia. Neurochem Int 2018; 119:107-114. [PMID: 29360494 DOI: 10.1016/j.neuint.2018.01.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2017] [Revised: 12/18/2017] [Accepted: 01/16/2018] [Indexed: 01/16/2023]
Abstract
The brain consists of neurons and much higher number of glial cells. They communicate each other, by which they control brain functions. The brain is highly vulnerable to several insults such as ischemia, but has a self-protective and self-repairing mechanisms against these. Ischemic tolerance or preconditioning is an endogenous neuroprotective phenomenon, where a mild non-lethal ischemic episode can induce resistance to a subsequent severe ischemic injury in the brain. Because of its neuroprotective effects against cerebral ischemia or stroke, ischemic tolerance has been widely studied. However, almost all studies have been performed from the viewpoint of neurons. Glial cells are structurally in close association with synapses. Recent studies have uncovered the active roles of astrocytes in modulating synaptic connectivity, such as synapse formation, elimination and maturation, during development or pathology. However, glia-mediated ischemic tolerance and/or neuronal repairing have received only limited attention. We and others have demonstrated that glial cells, especially astrocytes, play a pivotal role in regulation of induction of ischemic tolerance as well as repairing/remodeling of neuronal networks by phagocytosis. Here, we review our current understanding of (1) glial-mediated ischemic tolerance and (2) glia-mediated repairing/remodeling of the penumbra neuronal networks, and highlight their mechanisms as well as their potential benefits, problems, and therapeutic application.
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Affiliation(s)
- Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan.
| | - Yuri Hirayama
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
| | - Yosuke M Morizawa
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi 409-3898, Japan
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137
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Zorec R, Parpura V, Verkhratsky A. Astroglial vesicular network: evolutionary trends, physiology and pathophysiology. Acta Physiol (Oxf) 2018; 222. [PMID: 28665546 DOI: 10.1111/apha.12915] [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: 04/30/2017] [Revised: 05/17/2017] [Accepted: 06/24/2017] [Indexed: 12/13/2022]
Abstract
Intracellular organelles, including secretory vesicles, emerged when eukaryotic cells evolved some 3 billion years ago. The primordial organelles that evolved in Archaea were similar to endolysosomes, which developed, arguably, for specific metabolic tasks, including uptake, metabolic processing, storage and disposal of molecules. In comparison with prokaryotes, cell volume of eukaryotes increased by several orders of magnitude and vesicle traffic emerged to allow for communication between distant intracellular locations. Lysosomes, first described in 1955, a prominent intermediate of endo- and exocytotic pathways, operate virtually in all eukaryotic cells including astroglia, the most heterogeneous type of homeostatic glia in the central nervous system. Astrocytes support neuronal network activity in particular through elaborated secretion, based on a complex intracellular vesicle network dynamics. Deranged homeostasis underlies disease and astroglial vesicle traffic contributes to the pathophysiology of neurodegenerative (Alzheimer's disease, Huntington's disease), neurodevelopmental diseases (intellectual deficiency, Rett's disease) and neuroinfectious (Zika virus) disorders. This review addresses astroglial cell-autonomous vesicular traffic network, as well as its into primary and secondary vesicular network defects in diseases, and considers this network as a target for developing new therapies for neurological conditions.
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Affiliation(s)
- R. Zorec
- Laboratory of Neuroendocrinology and Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
- Celica; BIOMEDICAL; Ljubljana Slovenia
| | - V. Parpura
- Department of Neurobiology; Civitan International Research Center and Center for Glial Biology in Medicine; Evelyn F. McKnight Brain Institute; Atomic Force Microscopy and Nanotechnology Laboratories; University of Alabama; Birmingham AL USA
| | - A. Verkhratsky
- Laboratory of Neuroendocrinology and Molecular Cell Physiology; Institute of Pathophysiology; University of Ljubljana; Ljubljana Slovenia
- Celica; BIOMEDICAL; Ljubljana Slovenia
- Faculty of Biology; Medicine and Health; The University of Manchester; Manchester UK
- Achucarro Center for Neuroscience; IKERBASQUE; Basque Foundation for Science; Bilbao Spain
- Department of Neurosciences; University of the Basque Country UPV/EHU and CIBERNED; Leioa Spain
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138
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Sampedro-Piquero P, Begega A. Environmental Enrichment as a Positive Behavioral Intervention Across the Lifespan. Curr Neuropharmacol 2018; 15:459-470. [PMID: 27012955 PMCID: PMC5543669 DOI: 10.2174/1570159x14666160325115909] [Citation(s) in RCA: 80] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 06/30/2015] [Accepted: 03/16/2016] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND In recent decades, the interest in behavioral interventions has been growing due to the higher prevalence of age-related cognitive impairments. Hence, behavioral interventions, such as cognitive stimulation and physical activity, and along with these, our lifestyle (education level, work position, frequency of cognitive and social activities) have shown important benefits during the cognitive impairment, dementia and even recovery after brain injury. This is due to the fact that this type of intervention and activities promote the formation of a cognitive and brain reserve that allows tolerating brain damage during a long period of time without the appearance of cognitive symptoms. With regard to this, animal models have proved very useful in providing information about the brain mechanisms involved in the development of these cognitive and brain reserves and how they interact with each other. METHODS We summarize several studies showing the positive effects of Environmental Enrichment (EE), understood as a housing condition in which animals benefit from the sensory, physical, cognitive and social stimulation provided, on brain and cognitive functions usually impaired during aging. RESULTS Most of studies have shown that EE is a successful protocol to improve cognitive functions and reduce anxiety-related behaviors across the lifespan, as well as in animal models of neurodegenerative diseases. CONCLUSION Therefore, EE is a laboratory condition in which some aspects of an active lifestyle are reproduced.
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Affiliation(s)
- P Sampedro-Piquero
- Department of Biological and Health Psychology, Autonomous University of Madrid, Cantoblanco 28049, Madrid, Spain
| | - A Begega
- Neuroscience Laboratory, Psychology Department, University of Oviedo, Plaza Feijoo s/n 33003 Oviedo, INEUROPA, Spain
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139
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The Role of Mammalian Glial Cells in Circadian Rhythm Regulation. Neural Plast 2017; 2017:8140737. [PMID: 29435373 PMCID: PMC5757113 DOI: 10.1155/2017/8140737] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2017] [Accepted: 11/19/2017] [Indexed: 11/23/2022] Open
Abstract
Circadian rhythms are biological oscillations with a period of about 24 hours. These rhythms are maintained by an innate genetically determined time-keeping system called the circadian clock. A large number of the proteins involved in the regulation of this clock are transcription factors controlling rhythmic transcription of so-called clock-controlled genes, which participate in a plethora of physiological functions in the organism. In the brain, several areas, besides the suprachiasmatic nucleus, harbor functional clocks characterized by a well-defined time pattern of clock gene expression. This expression rhythm is not restricted to neurons but is also present in glia, suggesting that these cells are involved in circadian rhythmicity. However, only certain glial cells fulfill the criteria to be called glial clocks, namely, to display molecular oscillators based on the canonical clock protein PERIOD, which depends on the suprachiasmatic nucleus for their synchronization. In this contribution, we summarize the current information about activity of the clock genes in glial cells, their potential role as oscillators as well as clinical implications.
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140
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Evidence for astrocyte purinergic signaling in cortical sensory adaptation and serotonin-mediated neuromodulation. Mol Cell Neurosci 2017; 88:53-61. [PMID: 29277734 DOI: 10.1016/j.mcn.2017.12.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 12/16/2017] [Accepted: 12/19/2017] [Indexed: 11/22/2022] Open
Abstract
In the somatosensory cortex, inhibitory networks are involved in low frequency sensory input adaptation/habituation that can be observed as a paired-pulse depression when using a dual stimulus electrophysiological paradigm. Given that astrocytes have been shown to regulate inhibitory interneuron activity, we hypothesized that astrocytes are involved in cortical sensory adaptation/habituation and constitute effectors of the 5HT-mediated increase in frequency transmission. Using extracellular recordings of evoked excitatory postsynaptic potentials (eEPSPs) in layer II/III of somatosensory cortex, we used various pharmacological approaches to assess the recruitment of astrocyte signaling in paired-pulse depression and serotonin-mediated increase in the paired-pulse ratio (pulse 2/pulse 1). In the absence of neuromodulators or pharmacological agents, the first eEPSP is much larger in amplitude than the second due to the recruitment of long-lasting evoked GABAA-dependent inhibitory activity from the first stimulus. Disruption of glycolysis or mGluR5 signaling resulted in a very similar loss of paired-pulse depression in field recordings. Interestingly, paired-pulse depression was similarly sensitive to disruption by ATP P2Y and adenosine A2A receptor antagonists. In addition, we show that pharmacological disruption of paired-pulse depression by mGluR5, P2Y, and glycolysis inhibition precluded serotonin effects on frequency transmission (typically increased the paired-pulse ratio). These data highlight the possibility for astrocyte involvement in cortical inhibitory activity seen in this simple cortical network and that serotonin may act on astrocytes to exert some aspects of its modulatory influence.
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141
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Astrocytes and ischemic tolerance. Neurosci Res 2017; 126:53-59. [PMID: 29225139 DOI: 10.1016/j.neures.2017.11.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 11/20/2017] [Accepted: 11/20/2017] [Indexed: 11/22/2022]
Abstract
A mild non-lethal ischemic episode can induce resistance to a subsequent severe ischemic injury in the brain. This phenomenon is termed ischemic tolerance or ischemic preconditioning, and is an endogenous mechanism that can provide robust neuroprotection. Because of its neuroprotective effects against cerebral ischemia or stroke, ischemic tolerance has been widely studied. However, almost all studies have been performed from the viewpoint of neurons. Accumulating evidence suggests that glial cells have various roles in regulation of brain function, including modulation of synaptic transmission, neuronal excitation, and neuronal structure. In addition, astrocytes are closely related to homeostasis, stability of brain function, and protection of neurons. However, glial cells have received only limited attention with regard to ischemic tolerance. Cross-ischemic preconditioning is a phenomenon whereby non-ischemic preconditioning such as mechanical, thermal, and chemical treatment can induce ischemic tolerance. Of these, chemical treatments that affect the immune system can strongly induce ischemic tolerance, suggesting that glial cells may have important roles in this process. Indeed, we and others have demonstrated that glial cells, especially astrocytes, play a pivotal role in the induction of ischemic tolerance. This glial-mediated ischemic tolerance provides a robust and long-lasting neuroprotection against ischemic injury. In this review, we discuss the mechanisms underlying glial-mediated ischemic tolerance, as well as its potential benefits, problems, and therapeutic application.
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142
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Conte C, Lee R, Sarkar M, Terman D. A mathematical model of recurrent spreading depolarizations. J Comput Neurosci 2017; 44:203-217. [PMID: 29210004 DOI: 10.1007/s10827-017-0675-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Revised: 11/17/2017] [Accepted: 11/20/2017] [Indexed: 12/24/2022]
Abstract
A detailed biophysical model for a neuron/astrocyte network is developed in order to explore mechanisms responsible for the initiation and propagation of recurrent cortical spreading depolarizations. The model incorporates biophysical processes not considered in the earlier models. This includes a model for the Na+-glutamate transporter, which allows for a detailed description of reverse glutamate uptake. In particular, we consider the specific roles of elevated extracellular glutamate and K+ in the initiation, propagation and recurrence of spreading depolarizations.
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Affiliation(s)
- Cameron Conte
- Department of Mathematics, Ohio State University, Columbus, OH, USA
| | - Ray Lee
- Department of Mathematics, Ohio State University, Columbus, OH, USA
| | - Monica Sarkar
- Department of Mathematics, Ohio State University, Columbus, OH, USA
| | - David Terman
- Department of Mathematics, Ohio State University, Columbus, OH, USA.
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143
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Abstract
Fluorescent protein-based biosensors are indispensable molecular tools for life science research. The invention and development of high-fidelity biosensors for a particular molecule or molecular event often catalyze important scientific breakthroughs. Understanding the structural and functional organization of brain activities remain a subject for which optical sensors are in desperate need and of growing interest. Here, we review genetically encoded fluorescent sensors for imaging neuronal activities with a focus on the design principles and optimizations of various sensors. New bioluminescent sensors useful for deep-tissue imaging are also discussed. By highlighting the protein engineering efforts and experimental applications of these sensors, we can consequently analyze factors influencing their performance. Finally, we remark on how future developments can fill technological gaps and lead to new discoveries.
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Affiliation(s)
- Zhijie Chen
- California Institute for Quantitative Biosciences, QB3, University of California, Berkeley, CA 94720, USA
| | - Tan M. Truong
- Center for Membrane and Cell Physiology, and Biomedical Sciences (BIMS) Graduate Program, University of Virginia, Charlottesville, VA 22908, USA
| | - Hui-wang Ai
- Center for Membrane and Cell Physiology, and Biomedical Sciences (BIMS) Graduate Program, University of Virginia, Charlottesville, VA 22908, USA
- Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, VA 22908, USA
- Correspondence:
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144
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Heller JP, Rusakov DA. The Nanoworld of the Tripartite Synapse: Insights from Super-Resolution Microscopy. Front Cell Neurosci 2017; 11:374. [PMID: 29225567 PMCID: PMC5705901 DOI: 10.3389/fncel.2017.00374] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2017] [Accepted: 11/10/2017] [Indexed: 12/17/2022] Open
Abstract
Synaptic connections between individual nerve cells are fundamental to the process of information transfer and storage in the brain. Over the past decades a third key partner of the synaptic machinery has been unveiled: ultrathin processes of electrically passive astroglia which often surround pre- and postsynaptic structures. The recent advent of super-resolution (SR) microscopy has begun to uncover the dynamic nanoworld of synapses and their astroglial environment. Here we overview and discuss the current progress in our understanding of the synaptic nanoenvironment, as gleaned from the imaging methods that go beyond the diffraction limit of conventional light microscopy. We argue that such methods are essential to achieve a new level of comprehension pertinent to the principles of signal integration in the brain.
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Affiliation(s)
- Janosch P Heller
- UCL Institute of Neurology, University College London, London, United Kingdom
| | - Dmitri A Rusakov
- UCL Institute of Neurology, University College London, London, United Kingdom.,Institute of Neuroscience, University of Nizhny Novgorod, Nizhny Novgorod, Russia
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145
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Blunted mGluR Activation Disinhibits Striatopallidal Transmission in Parkinsonian Mice. Cell Rep 2017; 17:2431-2444. [PMID: 27880915 PMCID: PMC5489133 DOI: 10.1016/j.celrep.2016.10.087] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 09/07/2016] [Accepted: 10/27/2016] [Indexed: 01/10/2023] Open
Abstract
The prevailing circuit model predicts that hyperactivity of the striatopallidal pathway and subsequently increased inhibition of external globus pallidus (GPe) neurons lead to the hypokinetic symptoms of Parkinson's disease (PD). It is believed that hyperactivity of the striatopallidal pathway is due to inactivity of dopamine receptors on the somatodendritic membrane of striatopallidal neurons, but the exact cellular underpinnings remain unclear. In this study, we show that mouse GPe astrocytes critically control ambient glutamate level, which in turn gates striatopallidal transmission via the activation of presynaptic metabotropic glutamate receptors. This presynaptic inhibition of striatopallidal transmission is diminished after the chronic loss of dopamine. Elevation of intracellular glutamate content in astrocytes restores the proper regulation of the striatopallidal input in PD models. These findings argue that astrocytes are key regulators of the striatopallidal synapse. Targeting this cell class may serve as an alternative therapeutic strategy for PD.
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146
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Meneses CS, Müller HY, Herzberg DE, Uberti B, Bustamante HA, Werner MP. Immunofluorescence characterization of spinal cord dorsal horn microglia and astrocytes in horses. PeerJ 2017; 5:e3965. [PMID: 29085760 PMCID: PMC5661433 DOI: 10.7717/peerj.3965] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/06/2017] [Indexed: 12/12/2022] Open
Abstract
The role of glial cells in pain modulation has recently gathered attention. The objective of this study was to determine healthy spinal microglia and astrocyte morphology and disposition in equine spinal cord dorsal horns using Iba-1 and GFAP/Cx-43 immunofluorescence labeling, respectively. Five adult horses without visible wounds or gait alterations were selected. Spinal cord segments were obtained post-mortem for immunohistochemical and immunocolocalization assays. Immunodetection of spinal cord dorsal horn astrocytes was done using a polyclonal goat antibody raised against Glial Fibrillary Acidic Protein (GFAP) and a polyclonal rabbit antibody against Connexin 43 (Cx-43). For immunodetection of spinal cord dorsal horn microglia, a polyclonal rabbit antibody against a synthetic peptide corresponding to the C-terminus of ionized calcium-binding adaptor molecule 1 (Iba-1) was used. Epifluorescence and confocal images were obtained for the morphological and organizational analysis. Evaluation of shape, area, cell diameter, cell process length and thickness was performed on dorsal horn microglia and astrocyte. Morphologically, an amoeboid spherical shape with a mean cell area of 92.4 + 34 µm2 (in lamina I, II and III) was found in horse microglial cells, located primarily in laminae I, II and III. Astrocyte primary stem branches (and cellular bodies to a much lesser extent) are mainly detected using GFAP. Thus, double GFAP/Cx-43 immunolabeling was needed in order to accurately characterize the morphology, dimension and cell density of astrocytes in horses. Horse and rodent astrocytes seem to have similar dimensions and localization. Horse astrocyte cells have an average diameter of 56 + 14 µm, with a main process length of 28 + 8 µm, and thickness of 1.4 + 0.3 µm, mainly situated in laminae I, II and III. Additionally, a close association between end-point astrocyte processes and microglial cell bodies was found. These results are the first characterization of cell morphology and organizational aspects of horse spinal glia. Iba-1 and GFAP/Cx-43 can successfully immune-label microglia and astrocytes respectively in horse spinal cords, and thus reveal cell morphology and corresponding distribution within the dorsal horn laminae of healthy horses. The conventional hyper-ramified shape that is normally visible in resting microglial cells was not found in horses. Instead, horse microglial cells had an amoeboid spherical shape. Horse protoplasmic astroglia is significantly smaller and structurally less complex than human astrocytes, with fewer main GFAP processes. Instead, horse astrocytes tend to be similar to those found in rodent’s model, with small somas and large cell processes. Microglia and astrocytes were found in the more superficial regions of the dorsal horn, similarly to that previously observed in humans and rodents. Further studies are needed to demonstrate the molecular mechanisms involved in the neuron-glia interaction in horses.
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Affiliation(s)
| | - Heine Yacob Müller
- Veterinary Sciences Graduate School, Universidad Austral de Chile, Valdivia, Chile
| | | | - Benjamín Uberti
- Veterinary Clinical Sciences Department, Universidad Austral de Chile, Valdivia, Chile
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147
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Taheri M, Handy G, Borisyuk A, White JA. Diversity of Evoked Astrocyte Ca 2+ Dynamics Quantified through Experimental Measurements and Mathematical Modeling. Front Syst Neurosci 2017; 11:79. [PMID: 29109680 PMCID: PMC5660282 DOI: 10.3389/fnsys.2017.00079] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Accepted: 10/04/2017] [Indexed: 01/06/2023] Open
Abstract
Astrocytes are a major cell type in the mammalian brain. They are not electrically excitable, but generate prominent Ca2+ signals related to a wide variety of critical functions. The mechanisms driving these Ca2+ events remain incompletely understood. In this study, we integrate Ca2+ imaging, quantitative data analysis, and mechanistic computational modeling to study the spatial and temporal heterogeneity of cortical astrocyte Ca2+ transients evoked by focal application of ATP in mouse brain slices. Based on experimental results, we tune a single-compartment mathematical model of IP3-dependent Ca2+ responses in astrocytes and use that model to study response heterogeneity. Using information from the experimental data and the underlying bifurcation structure of our mathematical model, we categorize all astrocyte Ca2+ responses into four general types based on their temporal characteristics: Single-Peak, Multi-Peak, Plateau, and Long-Lasting responses. We find that the distribution of experimentally-recorded response types depends on the location within an astrocyte, with somatic responses dominated by Single-Peak (SP) responses and large and small processes generating more Multi-Peak responses. On the other hand, response kinetics differ more between cells and trials than with location within a given astrocyte. We use the computational model to elucidate possible sources of Ca2+ response variability: (1) temporal dynamics of IP3, and (2) relative flux rates through Ca2+ channels and pumps. Our model also predicts the effects of blocking Ca2+ channels/pumps; for example, blocking store-operated Ca2+ (SOC) channels in the model eliminates Plateau and Long-Lasting responses (consistent with previous experimental observations). Finally, we propose that observed differences in response type distributions between astrocyte somas and processes can be attributed to systematic differences in IP3 rise durations and Ca2+ flux rates.
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Affiliation(s)
- Marsa Taheri
- Department of Bioengineering, University of Utah, Salt Lake City, UT, United States
| | - Gregory Handy
- Department of Mathematics, University of Utah, Salt Lake City, UT, United States
| | - Alla Borisyuk
- Department of Mathematics, University of Utah, Salt Lake City, UT, United States
| | - John A White
- Department of Biomedical Engineering, Boston University, Boston, MA, United States
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148
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Ephaptic Coupling of Cortical Neurons: Possible Contribution of Astroglial Magnetic Fields? Neuroscience 2017; 370:37-45. [PMID: 28793233 DOI: 10.1016/j.neuroscience.2017.07.072] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2017] [Revised: 06/17/2017] [Accepted: 07/31/2017] [Indexed: 02/08/2023]
Abstract
The close anatomical and functional relationship between neuronal circuits and the astroglial network in the neocortex has been demonstrated at several organization levels supporting the idea that neuron-astroglial crosstalk can play a key role in information processing. In addition to chemical and electrical neurotransmission, other non-synaptic mechanisms called ephaptic interactions seem to be important to understand neuronal coupling and cognitive functions. Recent interest in this issue comes from the fact that extra-cranial electric and magnetic field stimulations have shown therapeutic actions in the clinical practice. The present paper reviews the current knowledge regarding the ephaptic effects in mammalian neocortex and proposes that astroglial bio-magnetic fields associated with Ca2+ transients could be implicated in the ephaptic coupling of neurons by a direct magnetic modulation of the intercellular local field potentials.
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149
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Muller MS, Taylor CW. ATP evokes Ca 2+ signals in cultured foetal human cortical astrocytes entirely through G protein-coupled P2Y receptors. J Neurochem 2017; 142:876-885. [PMID: 28677119 PMCID: PMC5601250 DOI: 10.1111/jnc.14119] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 05/15/2017] [Accepted: 06/29/2017] [Indexed: 01/07/2023]
Abstract
Extracellular ATP plays important roles in coordinating the activities of astrocytes and neurons, and aberrant signalling is associated with neurodegenerative diseases. In rodents, ATP stimulates opening of Ca2+‐permeable channels formed by P2X receptor subunits in the plasma membrane. It is widely assumed, but not verified, that P2X receptors also evoke Ca2+ signals in human astrocytes. Here, we directly assess this hypothesis. We showed that cultured foetal cortical human astrocytes express mRNA for several P2X receptor subunits (P2X4, P2X5, P2X6) and G protein‐coupled P2Y receptors (P2Y1, P2Y2, P2Y6, P2Y11). In these astrocytes, ATP stimulated Ca2+ release from intracellular stores through IP3 receptors and store‐operated Ca2+ entry. These responses were entirely mediated by P2Y1 and P2Y2 receptors. Agonists of P2X receptors did not evoke Ca2+ signals, and nor did ATP when Ca2+ release from intracellular stores and store‐operated Ca2+ entry were inhibited. We conclude that ATP‐evoked Ca2+ signals in cultured human foetal astrocytes are entirely mediated by P2Y1 and P2Y2 receptors, with no contribution from P2X receptors. ![]()
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Affiliation(s)
- Margit S Muller
- Department of Pharmacology, University of Cambridge, Cambridge, UK
| | - Colin W Taylor
- Department of Pharmacology, University of Cambridge, Cambridge, UK
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150
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Wang Y, Shi G, Miller DJ, Wang Y, Wang C, Broussard G, Wang Y, Tian L, Yu G. Automated Functional Analysis of Astrocytes from Chronic Time-Lapse Calcium Imaging Data. Front Neuroinform 2017; 11:48. [PMID: 28769780 PMCID: PMC5509822 DOI: 10.3389/fninf.2017.00048] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Accepted: 06/30/2017] [Indexed: 01/12/2023] Open
Abstract
Recent discoveries that astrocytes exert proactive regulatory effects on neural information processing and that they are deeply involved in normal brain development and disease pathology have stimulated broad interest in understanding astrocyte functional roles in brain circuit. Measuring astrocyte functional status is now technically feasible, due to recent advances in modern microscopy and ultrasensitive cell-type specific genetically encoded Ca2+ indicators for chronic imaging. However, there is a big gap between the capability of generating large dataset via calcium imaging and the availability of sophisticated analytical tools for decoding the astrocyte function. Current practice is essentially manual, which not only limits analysis throughput but also risks introducing bias and missing important information latent in complex, dynamic big data. Here, we report a suite of computational tools, called Functional AStrocyte Phenotyping (FASP), for automatically quantifying the functional status of astrocytes. Considering the complex nature of Ca2+ signaling in astrocytes and low signal to noise ratio, FASP is designed with data-driven and probabilistic principles, to flexibly account for various patterns and to perform robustly with noisy data. In particular, FASP explicitly models signal propagation, which rules out the applicability of tools designed for other types of data. We demonstrate the effectiveness of FASP using extensive synthetic and real data sets. The findings by FASP were verified by manual inspection. FASP also detected signals that were missed by purely manual analysis but could be confirmed by more careful manual examination under the guidance of automatic analysis. All algorithms and the analysis pipeline are packaged into a plugin for Fiji (ImageJ), with the source code freely available online at https://github.com/VTcbil/FASP.
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Affiliation(s)
- Yinxue Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State UniversityArlington, VA, United States
| | - Guilai Shi
- Department of Biochemistry and Molecular Medicine, University of California Davis School of MedicineDavis, CA, United States
| | - David J Miller
- Department of Electrical Engineering, School of Electrical Engineering and Computer Science, Pennsylvania State UniversityUniversity Park, PA, United States
| | - Yizhi Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State UniversityArlington, VA, United States
| | - Congchao Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State UniversityArlington, VA, United States
| | - Gerard Broussard
- Department of Biochemistry and Molecular Medicine, University of California Davis School of MedicineDavis, CA, United States
| | - Yue Wang
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State UniversityArlington, VA, United States
| | - Lin Tian
- Department of Biochemistry and Molecular Medicine, University of California Davis School of MedicineDavis, CA, United States
| | - Guoqiang Yu
- Bradley Department of Electrical and Computer Engineering, Virginia Polytechnic Institute and State UniversityArlington, VA, United States
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