201
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How is flexible electronics advancing neuroscience research? Biomaterials 2020; 268:120559. [PMID: 33310538 DOI: 10.1016/j.biomaterials.2020.120559] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2020] [Revised: 11/16/2020] [Accepted: 11/18/2020] [Indexed: 02/07/2023]
Abstract
Innovative neurotechnology must be leveraged to experimentally answer the multitude of pressing questions in modern neuroscience. Driven by the desire to address the existing neuroscience problems with newly engineered tools, we discuss in this review the benefits of flexible electronics for neuroscience studies. We first introduce the concept and define the properties of flexible and stretchable electronics. We then categorize the four dimensions where flexible electronics meets the demands of modern neuroscience: chronic stability, interfacing multiple structures, multi-modal compatibility, and neuron-type-specific recording. Specifically, with the bending stiffness now approaching that of neural tissue, implanted flexible electronic devices produce little shear motion, minimizing chronic immune responses and enabling recording and stimulation for months, and even years. The unique mechanical properties of flexible electronics also allow for intimate conformation to the brain, the spinal cord, peripheral nerves, and the retina. Moreover, flexible electronics enables optogenetic stimulation, microfluidic drug delivery, and neural activity imaging during electrical stimulation and recording. Finally, flexible electronics can enable neuron-type identification through analysis of high-fidelity recorded action potentials facilitated by its seamless integration with the neural circuitry. We argue that flexible electronics will play an increasingly important role in neuroscience studies and neurological therapies via the fabrication of neuromorphic devices on flexible substrates and the development of enhanced methods of neuronal interpenetration.
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202
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Kwon HS, Koh SH. Neuroinflammation in neurodegenerative disorders: the roles of microglia and astrocytes. Transl Neurodegener 2020; 9:42. [PMID: 33239064 PMCID: PMC7689983 DOI: 10.1186/s40035-020-00221-2] [Citation(s) in RCA: 898] [Impact Index Per Article: 224.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 11/03/2020] [Indexed: 12/14/2022] Open
Abstract
Neuroinflammation is associated with neurodegenerative diseases, such as Alzheimer’s disease, Parkinson’s disease, and amyotrophic lateral sclerosis. Microglia and astrocytes are key regulators of inflammatory responses in the central nervous system. The activation of microglia and astrocytes is heterogeneous and traditionally categorized as neurotoxic (M1-phenotype microglia and A1-phenotype astrocytes) or neuroprotective (M2-phenotype microglia and A2-phenotype astrocytes). However, this dichotomized classification may not reflect the various phenotypes of microglia and astrocytes. The relationship between these activated glial cells is also very complicated, and the phenotypic distribution can change, based on the progression of neurodegenerative diseases. A better understanding of the roles of microglia and astrocytes in neurodegenerative diseases is essential for developing effective therapies. In this review, we discuss the roles of inflammatory response in neurodegenerative diseases, focusing on the contributions of microglia and astrocytes and their relationship. In addition, we discuss biomarkers to measure neuroinflammation and studies on therapeutic drugs that can modulate neuroinflammation.
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Affiliation(s)
- Hyuk Sung Kwon
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea
| | - Seong-Ho Koh
- Department of Neurology, Hanyang University College of Medicine, Seoul, Republic of Korea. .,Department of Translational Medicine, Hanyang University Graduate School of Biomedical Science & Engineering, Seoul, Republic of Korea.
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203
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Kadry H, Noorani B, Cucullo L. A blood-brain barrier overview on structure, function, impairment, and biomarkers of integrity. Fluids Barriers CNS 2020; 17:69. [PMID: 33208141 PMCID: PMC7672931 DOI: 10.1186/s12987-020-00230-3] [Citation(s) in RCA: 561] [Impact Index Per Article: 140.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Accepted: 11/07/2020] [Indexed: 02/07/2023] Open
Abstract
The blood–brain barrier is playing a critical role in controlling the influx and efflux of biological substances essential for the brain’s metabolic activity as well as neuronal function. Thus, the functional and structural integrity of the BBB is pivotal to maintain the homeostasis of the brain microenvironment. The different cells and structures contributing to developing this barrier are summarized along with the different functions that BBB plays at the brain–blood interface. We also explained the role of shear stress in maintaining BBB integrity. Furthermore, we elaborated on the clinical aspects that correlate between BBB disruption and different neurological and pathological conditions. Finally, we discussed several biomarkers that can help to assess the BBB permeability and integrity in-vitro or in-vivo and briefly explain their advantages and disadvantages.
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Affiliation(s)
- Hossam Kadry
- Department of Pharmaceutical Sciences, Jerry H. Hodge School of Pharmacy, Texas Tech University Health Sciences Center, 1300 S. Coulter Street, Amarillo, TX, 79106, USA
| | - Behnam Noorani
- Department of Pharmaceutical Sciences, Jerry H. Hodge School of Pharmacy, Texas Tech University Health Sciences Center, 1300 S. Coulter Street, Amarillo, TX, 79106, USA
| | - Luca Cucullo
- Dept. of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Office 415, Rochester, MI, 48309, USA.
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204
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Alteration in the expression of inflammatory cytokines in primary hippocampal astrocytes in response to MK-801 through ERK1/2 and PI3K signals. Cytokine 2020; 138:155366. [PMID: 33187817 DOI: 10.1016/j.cyto.2020.155366] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 10/19/2020] [Accepted: 11/05/2020] [Indexed: 11/21/2022]
Abstract
Our previous study showed that dizocilpine (MK-801) induced schizophrenia-like behavior in rats, enhanced GFAP expression, and activated primary cultured hippocampal astrocytes. Astrocytes play an essential role in neuroinflammation and contribute to the crosstalk that generates chronic neuro-inflammation in neurological diseases. However, the effects of MK-801 treatment on astrocytic neuroinflammatory responses and its mechanism of action have not been studied in detail. To address this issue, IL1β, IL6, TNFα and IL10 expression and secretion levels were evaluated in hippocampal astrocytes in response to MK-801 for 24 h by ELISA and real-time PCR, with and without pretreatment of either the ERK1/2 inhibitor, PD98059 or the PI3K inhibitor, LY294002. Cell apoptosis, viability, and proliferation were also examined. MK-801 treatment did not induce hippocampal astrocytes apoptosis or proliferation, however, MK-801 enhanced astrocytes viability. Additionally, the expression and secretion levels of IL1β, IL6 and TNFα were elevated, but that of IL10 was decreased, in which ERK1/2 and PI3K signals were involved. These findings suggest that hippocampal astrocytes may regulate the expressions of inflammatory cytokines through ERK1/2 and PI3K signaling pathway to participate in the pathogenesis of schizophrenia.
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205
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Sterling JK, Adetunji MO, Guttha S, Bargoud AR, Uyhazi KE, Ross AG, Dunaief JL, Cui QN. GLP-1 Receptor Agonist NLY01 Reduces Retinal Inflammation and Neuron Death Secondary to Ocular Hypertension. Cell Rep 2020; 33:108271. [PMID: 33147455 PMCID: PMC7660987 DOI: 10.1016/j.celrep.2020.108271] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2020] [Revised: 08/03/2020] [Accepted: 09/23/2020] [Indexed: 12/16/2022] Open
Abstract
Glaucoma is the leading cause of irreversible blindness and is characterized by the death of retinal ganglion cells (RGCs). Recent studies have implicated pro-inflammatory microglia, macrophages, and A1 astrocytes in the pathogenesis of neurodegenerative diseases. The role of pro-inflammatory, neurotoxic A1 astrocytes in glaucoma is just beginning to be explored. Using a mouse model of glaucoma, we demonstrate that ocular hypertension is sufficient to trigger production of C1q, interleukin-1α (IL-1α), and tumor necrosis factor α (TNF-α), three cytokines necessary and sufficient to drive the formation of A1 astrocytes. Upregulation of these cytokines occurs first in CD11b+ CD11c+ cells followed by CD11b+ CD11c- cells. Ablation of this pathway, by either genetic deletions of C1qa, IL-1α, and TNF-α, or treatment with glucagon-like peptide-1 receptor agonist NLY01, reduces A1 astrocyte transformation and RGC death. Together, these results highlight a neuroinflammatory mechanism of glaucomatous neurodegeneration that can be therapeutically targeted by NLY01 administration.
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Affiliation(s)
- Jacob K Sterling
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Medical Scientist Training Program, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Modupe O Adetunji
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Samyuktha Guttha
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Albert R Bargoud
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Katherine E Uyhazi
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Ahmara G Ross
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Joshua L Dunaief
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Qi N Cui
- FM Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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206
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Kim YM, Kim HJ. Proteasome Inhibitor MG132 is Toxic and Inhibits the Proliferation of Rat Neural Stem Cells but Increases BDNF Expression to Protect Neurons. Biomolecules 2020; 10:biom10111507. [PMID: 33147870 PMCID: PMC7692322 DOI: 10.3390/biom10111507] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Revised: 10/21/2020] [Accepted: 10/27/2020] [Indexed: 12/31/2022] Open
Abstract
Regulation of protein expression is essential for maintaining normal cell function. Proteasomes play important roles in protein degradation and dysregulation of proteasomes is implicated in neurodegenerative disorders. In this study, using a proteasome inhibitor MG132, we showed that proteasome inhibition reduces neural stem cell (NSC) proliferation and is toxic to NSCs. Interestingly, MG132 treatment increased the percentage of neurons in both proliferation and differentiation culture conditions of NSCs. Proteasome inhibition reduced B-cell lymphoma 2 (Bcl-2)/Bcl-2 associated X protein ratio. In addition, MG132 treatment induced cAMP response element-binding protein phosphorylation and increased the expression of brain-derived neurotrophic factor transcripts and proteins. These data suggest that proteasome function is important for NSC survival and differentiation. Moreover, although MG132 is toxic to NSCs, it may increase neurogenesis. Therefore, by modifying MG132 chemical structure and developing none toxic proteasome inhibitors, neurogenic chemicals can be developed to control NSC cell fate.
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Affiliation(s)
| | - Hyun-Jung Kim
- Correspondence: ; Tel.: +82-2-820-5619; Fax: +82-2-816-7338
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207
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Augusto-Oliveira M, Arrifano GP, Takeda PY, Lopes-Araújo A, Santos-Sacramento L, Anthony DC, Verkhratsky A, Crespo-Lopez ME. Astroglia-specific contributions to the regulation of synapses, cognition and behaviour. Neurosci Biobehav Rev 2020; 118:331-357. [DOI: 10.1016/j.neubiorev.2020.07.039] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/29/2020] [Accepted: 07/29/2020] [Indexed: 12/11/2022]
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208
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Zhang H, Wang Y, Lian L, Zhang C, He Z. Glycine-Histidine-Lysine (GHK) Alleviates Astrocytes Injury of Intracerebral Hemorrhage via the Akt/miR-146a-3p/AQP4 Pathway. Front Neurosci 2020; 14:576389. [PMID: 33192260 PMCID: PMC7658812 DOI: 10.3389/fnins.2020.576389] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Accepted: 09/03/2020] [Indexed: 12/22/2022] Open
Abstract
Intracerebral hemorrhage (ICH) is a major type of cerebrovascular disease with poor prognosis. Recent studies have shown that Glycyl-l-histidyl-l-lysine (GHK) is a kind of natural human tripeptide which could inhibit inflammation and against neurodegenerative diseases, but neither its role nor the mechanisms in ICH have yet been explicit. Currently, we investigated the possible strategies of GHK on ICH injury. Neurological deficit scores, brain water content, Nissl staining, and aquaporin 4 (AQP4) immunohistochemistry were detected in different groups of rats. The expression of microRNAs (miRNAs) was examined by real-time PCR. Inflammatory factors were detected using enzyme-linked immunosorbent assay (ELISA). Cell viability and cell proliferation were detected by Cell Counting Kit-8 (CCK-8). Matrix metalloproteinase 2 (MMP2), MMP9, tissue inhibitors of metalloproteinase-1 (TIMP1), AQP4 expression were detected/assessed using western blot. We observed that 5 and 10 μg/g of GHK improved neurological recovery by significantly reducing brain water content, improving neurological deficits, and promoting neuron survival. Besides, GHK alleviated inflammatory reaction and downregulated AQP4 expression. Furthermore, the effects of GHK on astrocyte were associated with the upregulation of miRNA-146a-3p, which partially regulated the expression of AQP4. Our results demonstrated that the phosphatidylinositol 3-kinase (PI3K)/AKT pathway participated in the GHK-induced upregulation of miR-146a-3p and miR-146a-3p/AQP4 interaction plays a role in the injury following ICH. These findings suggested that GHK could provide a novel therapeutic strategy for ICH.
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Affiliation(s)
- Heyu Zhang
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China.,Department of Neurology, First Hospital of China Medical University, Shenyang, China
| | - Yanzhe Wang
- Department of Neurology, First Hospital of China Medical University, Shenyang, China
| | - Ling Lian
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Cheng Zhang
- Department of Neurology, The First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China.,Guangdong Provincial Key Laboratory of Diagnosis and Treatment of Major Neurological Diseases, National Key Clinical Department and Key Discipline of Neurology, Guangzhou, China
| | - Zhiyi He
- Department of Neurology, First Hospital of China Medical University, Shenyang, China
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209
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Soria FN, Miguelez C, Peñagarikano O, Tønnesen J. Current Techniques for Investigating the Brain Extracellular Space. Front Neurosci 2020; 14:570750. [PMID: 33177979 PMCID: PMC7591815 DOI: 10.3389/fnins.2020.570750] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 09/17/2020] [Indexed: 12/11/2022] Open
Abstract
The brain extracellular space (ECS) is a continuous reticular compartment that lies between the cells of the brain. It is vast in extent relative to its resident cells, yet, at the same time the nano- to micrometer dimensions of its channels and reservoirs are commonly finer than the smallest cellular structures. Our conventional view of this compartment as largely static and of secondary importance for brain function is rapidly changing, and its active dynamic roles in signaling and metabolite clearance have come to the fore. It is further emerging that ECS microarchitecture is highly heterogeneous and dynamic and that ECS geometry and diffusional properties directly modulate local diffusional transport, down to the nanoscale around individual synapses. The ECS can therefore be considered an extremely complex and diverse compartment, where numerous physiological events are unfolding in parallel on spatial and temporal scales that span orders of magnitude, from milliseconds to hours, and from nanometers to centimeters. To further understand the physiological roles of the ECS and identify new ones, researchers can choose from a wide array of experimental techniques, which differ greatly in their applicability to a given sample and the type of data they produce. Here, we aim to provide a basic introduction to the available experimental techniques that have been applied to address the brain ECS, highlighting their main characteristics. We include current gold-standard techniques, as well as emerging cutting-edge modalities based on recent super-resolution microscopy. It is clear that each technique comes with unique strengths and limitations and that no single experimental method can unravel the unknown physiological roles of the brain ECS on its own.
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Affiliation(s)
- Federico N. Soria
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Department of Neuroscience, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Cristina Miguelez
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
- Autonomic and Movement Disorders Unit, Neurodegenerative Diseases, Biocruces Health Research Institute, Barakaldo, Spain
| | - Olga Peñagarikano
- Department of Pharmacology, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
| | - Jan Tønnesen
- Achucarro Basque Center for Neuroscience, Leioa, Spain
- Department of Neuroscience, Faculty of Medicine and Nursing, University of the Basque Country (UPV/EHU), Leioa, Spain
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210
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Sinha S, Patro N, Tiwari PK, Patro IK. Maternal Spirulina supplementation during pregnancy and lactation partially prevents oxidative stress, glial activation and neuronal damage in protein malnourished F1 progeny. Neurochem Int 2020; 141:104877. [PMID: 33049335 DOI: 10.1016/j.neuint.2020.104877] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 09/17/2020] [Accepted: 10/06/2020] [Indexed: 02/06/2023]
Abstract
Protein malnutrition (PMN) is a global health issue but most prevalent in Africa and Asia. It exerts detrimental effect on structural and physiological aspects of hippocampal circuitry. Despite accumulating evidence for PMN induced changes in nervous system, relatively very little is known about how maternal nutritional supplementation during malnutrition affects glial cells and neurons. Herein, we aimed to investigate the effects of maternal Spirulina supplementation against PMN induced oxidative stress, reactive gliosis and neuronal damage in hippocampus of F1 progeny. Three months old healthy Sprague Dawley females (n = 24) were shifted to normoprotein (NC; 20% protein) and low protein (LP; 8% protein) diets 15 days before conception. The NC and LP group females were subdivided into two groups according to Spirulina supplementation (400 mg/kg/b.wt. orally throughout gestation and lactation period): normal control with Spirulina (NC SPI) and low protein with Spirulina supplemented group (LP SPI). F1 progeny born were used in present study. Thus, building on earlier results of ameliorated neurobehavioral and cognitive abilities in Spirulina supplemented protein deprived rats, the present study incorporates neurochemical and morphometric analysis of glial cells and neurons and revealed that maternal Spirulina consumption partially prevented the PMN associated neuropathological alterations in terms of attenuated oxidative brain damage, reduced reactive gliosis and apoptotic cell population, improved dendritic branch complexity with few damaged neurons and enhanced mushroom shaped spine density. The results suggest that cellular changes in hippocampus after PMN are partially restored after maternal Spirulina supplementation and one could envision intervention approaches using Spirulina against malnutrition.
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Affiliation(s)
- Shrstha Sinha
- School of Studies in Neuroscience, Jiwaji University, Gwalior, India; School of Studies in Zoology, Jiwaji University, Gwalior, India
| | - Nisha Patro
- School of Studies in Neuroscience, Jiwaji University, Gwalior, India
| | - P K Tiwari
- School of Studies in Zoology, Jiwaji University, Gwalior, India
| | - Ishan K Patro
- School of Studies in Neuroscience, Jiwaji University, Gwalior, India; School of Studies in Zoology, Jiwaji University, Gwalior, India.
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211
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Woods GA, Rommelfanger NJ, Hong G. Bioinspired Materials for In Vivo Bioelectronic Neural Interfaces. MATTER 2020; 3:1087-1113. [PMID: 33103115 PMCID: PMC7583599 DOI: 10.1016/j.matt.2020.08.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
The success of in vivo neural interfaces relies on their long-term stability and large scale in interrogating and manipulating neural activity after implantation. Conventional neural probes, owing to their limited spatiotemporal resolution and scale, face challenges for studying the massive, interconnected neural network in its native state. In this review, we argue that taking inspiration from biology will unlock the next generation of in vivo bioelectronic neural interfaces. Reducing the feature sizes of bioelectronic neural interfaces to mimic those of neurons enables high spatial resolution and multiplexity. Additionally, chronic stability at the device-tissue interface is realized by matching the mechanical properties of bioelectronic neural interfaces to those of the endogenous tissue. Further, modeling the design of neural interfaces after the endogenous topology of the neural circuitry enables new insights into the connectivity and dynamics of the brain. Lastly, functionalization of neural probe surfaces with coatings inspired by biology leads to enhanced tissue acceptance over extended timescales. Bioinspired neural interfaces will facilitate future developments in neuroscience studies and neurological treatments by leveraging bidirectional information transfer and integrating neuromorphic computing elements.
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Affiliation(s)
- Grace A. Woods
- Department of Applied Physics, Stanford University, Stanford, California, 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, California, 94305, USA
| | - Nicholas J. Rommelfanger
- Department of Applied Physics, Stanford University, Stanford, California, 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, California, 94305, USA
| | - Guosong Hong
- Department of Materials Science and Engineering, Stanford University, Stanford, California, 94305, USA
- Wu Tsai Neurosciences Institute, Stanford University, Stanford, California, 94305, USA
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212
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Ma X, Chen K, Cui Y, Huang G, Nehme A, Zhang L, Li H, Wei J, Liong K, Liu Q, Shi L, Wu J, Qiu S. Depletion of microglia in developing cortical circuits reveals its critical role in glutamatergic synapse development, functional connectivity, and critical period plasticity. J Neurosci Res 2020; 98:1968-1986. [PMID: 32594561 DOI: 10.1002/jnr.24641] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 04/23/2020] [Accepted: 04/25/2020] [Indexed: 02/05/2023]
Abstract
Microglia populate the early developing brain and mediate pruning of the central synapses. Yet, little is known on their functional significance in shaping the developing cortical circuits. We hypothesize that the developing cortical circuits require microglia for proper circuit maturation and connectivity, and as such, ablation of microglia during the cortical critical period may result in a long-lasting circuit abnormality. We administered PLX3397, a colony-stimulating factor 1 receptor inhibitor, to mice starting at postnatal day 14 and through P28, which depletes >75% of microglia in the visual cortex (VC). This treatment largely covers the critical period (P19-32) of VC maturation and plasticity. Patch clamp recording in VC layer 2/3 (L2/3) and L5 neurons revealed increased mEPSC frequency and reduced amplitude, and decreased AMPA/NMDA current ratio, indicative of altered synapse maturation. Increased spine density was observed in these neurons, potentially reflecting impaired synapse pruning. In addition, VC intracortical circuit functional connectivity, assessed by laser scanning photostimulation combined with glutamate uncaging, was dramatically altered. Using two photon longitudinal dendritic spine imaging, we confirmed that spine elimination/pruning was diminished during VC critical period when microglia were depleted. Reduced spine pruning thus may account for increased spine density and disrupted connectivity of VC circuits. Lastly, using single-unit recording combined with monocular deprivation, we found that ocular dominance plasticity in the VC was obliterated during the critical period as a result of microglia depletion. These data establish a critical role of microglia in developmental cortical synapse pruning, maturation, functional connectivity, and critical period plasticity.
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Affiliation(s)
- Xiaokuang Ma
- Department of Pharmacology, Shantou University Medical College, Shantou, China
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Ke Chen
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Yuehua Cui
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Guanqun Huang
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Antoine Nehme
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Le Zhang
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Handong Li
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Jing Wei
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Katerina Liong
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
| | - Qiang Liu
- Barrow Neurological Institute, St. Joseph's Hospital Medical Center, Phoenix, AZ, USA
| | - Lingling Shi
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, China
| | - Jie Wu
- Department of Pharmacology, Shantou University Medical College, Shantou, China
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
- Barrow Neurological Institute, St. Joseph's Hospital Medical Center, Phoenix, AZ, USA
| | - Shenfeng Qiu
- Basic Medical Sciences, University of Arizona College of Medicine-Phoenix, Phoenix, AZ, USA
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213
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Yang K, Zhou Y, Zhou L, Yan F, Guan L, Liu H, Liu W. Synaptic Plasticity After Focal Cerebral Ischemia Was Attenuated by Gap26 but Enhanced by GAP-134. Front Neurol 2020; 11:888. [PMID: 32982919 PMCID: PMC7479336 DOI: 10.3389/fneur.2020.00888] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 07/13/2020] [Indexed: 12/15/2022] Open
Abstract
Objective: Synaptic plasticity is critical for neurorehabilitation after focal cerebral ischemia. Connexin 43 (Cx43), the main component of the gap junction, has been shown to be pivotal for synaptic plasticity. The objective of this study was to investigate the role of the Cx43 inhibitor (Gap26) and gap junction modifier (GAP-134) in neurorehabilitation and to study their contribution to synaptic plasticity after focal ischemia. Methods: Time course expression of both total and phosphorylated Cx43 (p-Cx43) were detected by western blotting at 3, 7, and 14 d after focal ischemia. Gap26 and GAP-134 were administered starting from 3 d post focal ischemia. Neurological performances were evaluated by balance beam walking test and Y-maze test at 1, 3, and 7 d. Golgi staining and transmission electron microscope (TEM) detection were conducted at 7 d for observing dendritic spine numbers and synaptic ultrastructure, respectively. Immunofluorescent staining was used at 7 d for detection of synaptic plasticity markers, including synaptophysin (SYN) and growth-associated protein-43 (GAP-43). Results: Expression levels of both total Cx43 and p-Cx43 were increased after focal cerebral ischemia, peaking at 7 d. Compared with the MCAO group, Gap26 worsened the neurological behavior and decreased the dendritic spine number while GAP-134 improved the neurobehavior and increased the number of dendritic spines. Moreover, Gap26 further destroyed the synaptic structure, concomitant with downregulated SYN and GAP-43, whereas GAP-134 alleviated synaptic destruction and upregulated SYN and GAP-43. Conclusion: These findings suggested that Cx43 or the gap junction was involved in synaptic plasticity, thereby promoting neural recovery after ischemic stroke. Treatments enhancing gap junctions may be potential promising therapeutic measures for neurorehabilitation after ischemic stroke.
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Affiliation(s)
- Kailing Yang
- Department of Physiology, School of Basic Medical Science, Guangzhou University of Chinese Medicine, Guangzhou, China.,The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Ying Zhou
- Department of Physiology, School of Basic Medical Science, Guangzhou University of Chinese Medicine, Guangzhou, China.,The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Lequan Zhou
- Department of Physiology, School of Basic Medical Science, Guangzhou University of Chinese Medicine, Guangzhou, China.,The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Fuman Yan
- Department of Physiology, School of Basic Medical Science, Guangzhou University of Chinese Medicine, Guangzhou, China.,The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Li Guan
- Department of Physiology, School of Basic Medical Science, Guangzhou University of Chinese Medicine, Guangzhou, China.,The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Haimei Liu
- Department of Physiology, School of Basic Medical Science, Guangzhou University of Chinese Medicine, Guangzhou, China.,The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Wei Liu
- Department of Physiology, School of Basic Medical Science, Guangzhou University of Chinese Medicine, Guangzhou, China.,The Research Center of Basic Integrative Medicine, Guangzhou University of Chinese Medicine, Guangzhou, China
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214
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Fossati G, Matteoli M, Menna E. Astrocytic Factors Controlling Synaptogenesis: A Team Play. Cells 2020; 9:E2173. [PMID: 32993090 PMCID: PMC7600026 DOI: 10.3390/cells9102173] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 09/22/2020] [Accepted: 09/23/2020] [Indexed: 12/14/2022] Open
Abstract
Astrocytes are essential players in brain circuit development and homeostasis, controlling many aspects of synapse formation, function, plasticity and elimination both during development and adulthood. Accordingly, alterations in astrocyte morphogenesis and physiology may severely affect proper brain development, causing neurological or neuropsychiatric conditions. Recent findings revealed a huge astrocyte heterogeneity among different brain areas, which is likely at the foundation of the different synaptogenic potential of these cells in selected brain regions. This review highlights recent findings on novel mechanisms that regulate astrocyte-mediated synaptogenesis during development, and the control of synapse number in the critical period or upon synaptic plasticity.
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Affiliation(s)
- Giuliana Fossati
- Humanitas Clinical and Research Center—IRCCS—NeuroCenter, via Manzoni 56, 20089 Rozzano, Milan, Italy; (G.F.); (M.M.)
| | - Michela Matteoli
- Humanitas Clinical and Research Center—IRCCS—NeuroCenter, via Manzoni 56, 20089 Rozzano, Milan, Italy; (G.F.); (M.M.)
- CNR, Department of Biomedical Sciences, Institute of Neuroscience—URT Humanitas, via Manzoni 56, 20089 Rozzano, Italy
| | - Elisabetta Menna
- Humanitas Clinical and Research Center—IRCCS—NeuroCenter, via Manzoni 56, 20089 Rozzano, Milan, Italy; (G.F.); (M.M.)
- CNR, Department of Biomedical Sciences, Institute of Neuroscience—URT Humanitas, via Manzoni 56, 20089 Rozzano, Italy
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215
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Jin SX, Higashimori H, Schin C, Tamashiro A, Men Y, Chiang MSR, Jarvis R, Cox D, Feig L, Yang Y. Astroglial FMRP modulates synaptic signaling and behavior phenotypes in FXS mouse model. Glia 2020; 69:594-608. [PMID: 32970902 DOI: 10.1002/glia.23915] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 09/09/2020] [Accepted: 09/11/2020] [Indexed: 12/16/2022]
Abstract
Fragile X syndrome (FXS) is one of the most common inherited intellectual disability (ID) disorders, in which the loss of FMRP protein induces a range of cellular signaling changes primarily through excess protein synthesis. Although neuron-centered molecular and cellular events underlying FXS have been characterized, how different CNS cell types are involved in typical FXS synaptic signaling changes and behavioral phenotypes is largely unknown. Recent evidence suggests that selective loss of astroglial FMRP is able to dysregulate glutamate uptake, increase spine density, and impair motor-skill learning. Here we investigated the effect of astroglial FMRP on synaptic signaling and FXS-related behavioral and learning phenotypes in astroglial Fmr1 cKO and cON mice in which FMRP expression is selectively diminished or restored in astroglia. We found that selective loss of astroglial FMRP contributes to cortical hyperexcitability by enhancing NMDAR-mediated evoked but not spontaneous miniEPSCs and elongating cortical UP state duration. Selective loss of astroglial FMRP is also sufficient to increase locomotor hyperactivity, significantly diminish social novelty preference, and induce memory acquisition and extinction deficits in astroglial Fmr1 cKO mice. Importantly, re-expression of astroglial FMRP is able to significantly rescue the hyperactivity (evoked NMDAR response, UP state duration, and open field test) and social novelty preference in astroglial Fmr1 cON mice. These results demonstrate a profound role of astroglial FMRP in the evoked synaptic signaling, spontaneously occurring cortical UP states, and FXS-related behavioral and learning phenotypes and provide important new insights in the cell type consideration for the FMRP reactivation strategy.
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Affiliation(s)
- Shan-Xue Jin
- Department of Developmental, Molecular, and Cellular Biology, Tufts University, Boston, Massachusetts, USA
| | - Haruki Higashimori
- Department of Neuroscience, School of Medicine, Tufts University, Boston, Massachusetts, USA
| | - Christina Schin
- Department of Neuroscience, School of Medicine, Tufts University, Boston, Massachusetts, USA
| | - Alessandra Tamashiro
- Department of Neuroscience, School of Medicine, Tufts University, Boston, Massachusetts, USA
| | - Yuqin Men
- Department of Neuroscience, School of Medicine, Tufts University, Boston, Massachusetts, USA
| | - Ming Sum R Chiang
- Department of Neuroscience, School of Medicine, Tufts University, Boston, Massachusetts, USA
| | - Rachel Jarvis
- Department of Neuroscience, School of Medicine, Tufts University, Boston, Massachusetts, USA
| | - Dan Cox
- Department of Neuroscience, School of Medicine, Tufts University, Boston, Massachusetts, USA
| | - Larry Feig
- Department of Developmental, Molecular, and Cellular Biology, Tufts University, Boston, Massachusetts, USA.,Graduate School of Biomedical Sciences, Tufts University, Boston, Massachusetts, USA
| | - Yongjie Yang
- Department of Neuroscience, School of Medicine, Tufts University, Boston, Massachusetts, USA.,Graduate School of Biomedical Sciences, Tufts University, Boston, Massachusetts, USA
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216
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Dozio V, Daali Y, Desmeules J, Sanchez JC. Deep proteomics and phosphoproteomics reveal novel biological pathways perturbed by morphine, morphine-3-glucuronide and morphine-6-glucuronide in human astrocytes. J Neurosci Res 2020; 100:220-236. [PMID: 32954564 DOI: 10.1002/jnr.24731] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/06/2020] [Accepted: 08/31/2020] [Indexed: 01/08/2023]
Abstract
Tolerance and hyperalgesia associated with chronic exposure to morphine are major limitations in the clinical management of chronic pain. At a cellular level, neuronal signaling can in part account for these undesired side effects, but unknown mechanisms mediated by central nervous system glial cells are likely also involved. Here we applied data-independent acquisition mass spectrometry to perform a deep proteome and phosphoproteome analysis of how human astrocytes responds to opioid stimulation. We unveil time- and dose-dependent effects induced by morphine and its major active metabolites morphine-3-glucuronide (M3G) and morphine-6-glucuronide that converging on activation of mitogen-activated protein kinase and mammalian target of rapamycin signaling pathways. We also find that especially longer exposure to M3G leads to significant dysregulation of biological pathways linked to extracellular matrix organization, antigen presentation, cell adhesion, and glutamate homeostasis, which are crucial for neuron- and leukocyte-astrocyte interactions.
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Affiliation(s)
- Vito Dozio
- Department of Medicine, University of Geneva, Geneva, Switzerland.,Swiss Centre for Applied Human Toxicology, Basel, Switzerland
| | - Youssef Daali
- Swiss Centre for Applied Human Toxicology, Basel, Switzerland.,Division of Clinical Pharmacology and Toxicology, Department of Anesthesiology, Pharmacology, Emergency Medicine and Intensive Cares, Geneva University Hospitals, Geneva, Switzerland
| | - Jules Desmeules
- Swiss Centre for Applied Human Toxicology, Basel, Switzerland.,Division of Clinical Pharmacology and Toxicology, Department of Anesthesiology, Pharmacology, Emergency Medicine and Intensive Cares, Geneva University Hospitals, Geneva, Switzerland
| | - Jean-Charles Sanchez
- Department of Medicine, University of Geneva, Geneva, Switzerland.,Swiss Centre for Applied Human Toxicology, Basel, Switzerland
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217
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Murta V, Villarreal A, Ramos AJ. Severe Acute Respiratory Syndrome Coronavirus 2 Impact on the Central Nervous System: Are Astrocytes and Microglia Main Players or Merely Bystanders? ASN Neuro 2020; 12:1759091420954960. [PMID: 32878468 PMCID: PMC7476346 DOI: 10.1177/1759091420954960] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
With confirmed coronavirus disease 2019 (COVID-19) cases surpassing the 18 million mark around the globe, there is an imperative need to gain comprehensive understanding of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although the main clinical manifestations of COVID-19 are associated with respiratory or intestinal symptoms, reports of neurological signs and symptoms are increasing. The etiology of these neurological manifestations remains obscure, and probably involves several direct pathways, not excluding the direct entry of the virus to the central nervous system (CNS) through the olfactory epithelium, circumventricular organs, or disrupted blood–brain barrier. Furthermore, neuroinflammation might occur in response to the strong systemic cytokine storm described for COVID-19, or due to dysregulation of the CNS rennin-angiotensin system. Descriptions of neurological manifestations in patients in the previous coronavirus (CoV) outbreaks have been numerous for the SARS-CoV and lesser for Middle East respiratory syndrome coronavirus (MERS-CoV). Strong evidence from patients and experimental models suggests that some human variants of CoV have the ability to reach the CNS and that neurons, astrocytes, and/or microglia can be target cells for CoV. A growing body of evidence shows that astrocytes and microglia have a major role in neuroinflammation, responding to local CNS inflammation and/or to disbalanced peripheral inflammation. This is another potential mechanism for SARS-CoV-2 damage to the CNS. In this comprehensive review, we will summarize the known neurological manifestations of SARS-CoV-2, SARS-CoV and MERS-CoV; explore the potential role for astrocytes and microglia in the infection and neuroinflammation; and compare them with the previously described human and animal CoV that showed neurotropism to propose possible underlying mechanisms.
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Affiliation(s)
- Veronica Murta
- Laboratorio de Neuropatología Molecular, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis," Facultad de Medicina, UBA-CONICET, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
| | - Alejandro Villarreal
- Laboratorio de Neuropatología Molecular, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis," Facultad de Medicina, UBA-CONICET, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
| | - Alberto J Ramos
- Laboratorio de Neuropatología Molecular, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis," Facultad de Medicina, UBA-CONICET, Universidad de Buenos Aires, Ciudad de Buenos Aires, Argentina
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218
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An efficient neuron-astrocyte differentiation protocol from human embryonic stem cell-derived neural progenitors to assess chemical-induced developmental neurotoxicity. Reprod Toxicol 2020; 98:107-116. [PMID: 32931842 DOI: 10.1016/j.reprotox.2020.09.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Revised: 08/13/2020] [Accepted: 09/07/2020] [Indexed: 01/10/2023]
Abstract
Human embryonic stem cell neuronal differentiation models provide promising in vitro tools for the prediction of developmental neurotoxicity of chemicals. Such models mimic essential elements of human relevant neuronal development, including the differentiation of a variety of brain cell types and their neuronal network formation as evidenced by specific gene and protein biomarkers. However, the reproducibility and lengthy culture duration of cell models present drawbacks and delay regulatory implementation. Here we present a relatively short and robust protocol to differentiate H9-derived neural progenitor cells (NPCs) into a neuron-astrocyte co-culture. When frozen-stored NPCs were re-cultured and induced into neuron-astrocyte differentiation, they showed gene- and protein expression typical for these cells, and most notably they exhibited spontaneous electrical activity within three days of culture as measured by a multi-well micro-electrode array. Modulating the ratio of astrocytes and neurons through different growth factors including glial cell line-derived neurotrophic factor (GDNF), brain-derived neurotrophic factor (BDNF), and ciliary neurotrophic factor (CNTF) did not compromise the ability to develop spontaneous electrical activity. This robust neuronal differentiation model may serve as a functional component of a testing strategy for unravelling mechanisms of developmental neurotoxicity.
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219
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Matsui T, Miyamoto N, Saito F, Shinozawa T. Molecular Profiling of Human Induced Pluripotent Stem Cell-Derived Cells and their Application for Drug Safety Study. Curr Pharm Biotechnol 2020; 21:807-828. [PMID: 32321398 DOI: 10.2174/1389201021666200422090952] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Revised: 12/10/2019] [Accepted: 03/02/2020] [Indexed: 12/13/2022]
Abstract
Drug-induced toxicity remains one of the leading causes of discontinuation of the drug candidate and post-marketing withdrawal. Thus, early identification of the drug candidates with the potential for toxicity is crucial in the drug development process. With the recent discovery of human- Induced Pluripotent Stem Cells (iPSC) and the establishment of the differentiation protocol of human iPSC into the cell types of interest, the differentiated cells from human iPSC have garnered much attention because of their potential applicability in toxicity evaluation as well as drug screening, disease modeling and cell therapy. In this review, we expanded on current information regarding the feasibility of human iPSC-derived cells for the evaluation of drug-induced toxicity with a focus on human iPSCderived hepatocyte (iPSC-Hep), cardiomyocyte (iPSC-CMs) and neurons (iPSC-Neurons). Further, we CSAHi, Consortium for Safety Assessment using Human iPS Cells, reported our gene expression profiling data with DNA microarray using commercially available human iPSC-derived cells (iPSC-Hep, iPSC-CMs, iPSC-Neurons), their relevant human tissues and primary cultured human cells to discuss the future direction of the three types of human iPSC-derived cells.
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Affiliation(s)
- Toshikatsu Matsui
- Consortium for Safety Assessment using Human iPS Cells (CSAHi), Japan
| | - Norimasa Miyamoto
- Consortium for Safety Assessment using Human iPS Cells (CSAHi), Japan
| | - Fumiyo Saito
- Consortium for Safety Assessment using Human iPS Cells (CSAHi), Japan
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220
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Live-imaging of astrocyte morphogenesis and function in zebrafish neural circuits. Nat Neurosci 2020; 23:1297-1306. [PMID: 32895565 PMCID: PMC7530038 DOI: 10.1038/s41593-020-0703-x] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Accepted: 07/24/2020] [Indexed: 01/10/2023]
Abstract
How astrocytes grow and integrate into neural circuits remains poorly defined. Zebrafish are well-suited for such investigations, but bona fide astrocytes have not been described in this system. Here, we characterize a zebrafish cell type that is remarkably similar to mammalian astrocytes that derive from radial glial cells and elaborate processes to establish their territories at early larval stages. Zebrafish astrocytes associate closely with synapses, tile with one another, and express markers including Glast and glutamine synthetase. Once integrated into circuits, they exhibit whole-cell and microdomain Ca2+ transients, which are sensitive to norepinephrine. Finally, using a cell-specific CRISPR/Cas9 approach we demonstrate that fgfr3/4 are required for vertebrate astrocyte morphogenesis. This work provides the first visualization of astrocyte morphogenesis from stem cell to post-mitotic astrocyte in vivo, identifies a role for Fgf receptors in vertebrate astrocytes, and establishes zebrafish as a valuable new model system to study astrocyte biology in vivo.
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221
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Astrocytic Ephrin-B1 Controls Excitatory-Inhibitory Balance in Developing Hippocampus. J Neurosci 2020; 40:6854-6871. [PMID: 32801156 DOI: 10.1523/jneurosci.0413-20.2020] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 06/08/2020] [Accepted: 07/20/2020] [Indexed: 12/12/2022] Open
Abstract
Astrocytes are implicated in synapse formation and elimination, which are associated with developmental refinements of neuronal circuits. Astrocyte dysfunctions are also linked to synapse pathologies associated with neurodevelopmental disorders and neurodegenerative diseases. Although several astrocyte-derived secreted factors are implicated in synaptogenesis, the role of contact-mediated glial-neuronal interactions in synapse formation and elimination during development is still unknown. In this study, we examined whether the loss or overexpression of the membrane-bound ephrin-B1 in astrocytes during postnatal day (P) 14-28 period would affect synapse formation and maturation in the developing hippocampus. We found enhanced excitation of CA1 pyramidal neurons in astrocyte-specific ephrin-B1 KO male mice, which coincided with a greater vGlut1/PSD95 colocalization, higher dendritic spine density, and enhanced evoked AMPAR and NMDAR EPSCs. In contrast, EPSCs were reduced in CA1 neurons neighboring ephrin-B1-overexpressing astrocytes. Overexpression of ephrin-B1 in astrocytes during P14-28 developmental period also facilitated evoked IPSCs in CA1 neurons, while evoked IPSCs and miniature IPSC amplitude were reduced following astrocytic ephrin-B1 loss. Lower numbers of parvalbumin-expressing cells and a reduction in the inhibitory VGAT/gephyrin-positive synaptic sites on CA1 neurons in the stratum pyramidale and stratum oriens layers of KO hippocampus may contribute to reduced inhibition and higher excitation. Finally, dysregulation of excitatory/inhibitory balance in KO male mice is most likely responsible for impaired sociability observed in these mice. The ability of astrocytic ephrin-B1 to influence both excitatory and inhibitory synapses during development can potentially contribute to developmental refinement of neuronal circuits.SIGNIFICANCE STATEMENT This report establishes a link between astrocytes and the development of excitatory and inhibitory balance in the mouse hippocampus during early postnatal development. We provide new evidence that astrocytic ephrin-B1 differentially regulates development of excitatory and inhibitory circuits in the hippocampus during early postnatal development using a multidisciplinary approach. The ability of astrocytic ephrin-B1 to influence both excitatory and inhibitory synapses during development can potentially contribute to developmental refinement of neuronal circuits and associated behaviors. Given widespread and growing interest in the astrocyte-mediated mechanisms that regulate synapse development, and the role of EphB receptors in neurodevelopmental disorders, these findings establish a foundation for future studies of astrocytes in clinically relevant conditions.
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222
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Antineuroinflammatory therapy: potential treatment for autism spectrum disorder by inhibiting glial activation and restoring synaptic function. CNS Spectr 2020; 25:493-501. [PMID: 31659946 DOI: 10.1017/s1092852919001603] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder that is characterized by deficits in social interactions and perseverative and stereotypical behavior. Growing evidence points toward a critical role for synaptic dysfunction in the onset of ASD, and synaptic function is influenced by glial cells. Considering the evidence that neuroinflammation in ASD is mediated by glial cells, one hypothesis is that reactive glial cells, under inflammatory conditions, contribute to the loss of synaptic functions and trigger ASD. Ongoing pharmacological treatments for ASD, including oxytocin, vitamin D, sulforaphane, and resveratrol, are promising and are shown to lead to improvements in behavioral performance in ASD. More importantly, their pharmacological mechanisms are closely related to anti-inflammation and synaptic protection. We focus this review on the hypothesis that synaptic dysfunction caused by reactive glial cells would lead to ASD, and discuss the potentials of antineuroinflammatory therapy for ASD.
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223
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Dysregulated Glial Differentiation in Schizophrenia May Be Relieved by Suppression of SMAD4- and REST-Dependent Signaling. Cell Rep 2020; 27:3832-3843.e6. [PMID: 31242417 DOI: 10.1016/j.celrep.2019.05.088] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2018] [Revised: 04/04/2019] [Accepted: 05/22/2019] [Indexed: 12/22/2022] Open
Abstract
Astrocytic differentiation is developmentally impaired in patients with childhood-onset schizophrenia (SCZ). To determine why, we used genetic gain- and loss-of-function studies to establish the contributions of differentially expressed transcriptional regulators to the defective differentiation of glial progenitor cells (GPCs) produced from SCZ patient-derived induced pluripotent cells (iPSCs). Negative regulators of the bone morphogenetic protein (BMP) pathway were upregulated in SCZ GPCs, including BAMBI, FST, and GREM1, whose overexpression retained SCZ GPCs at the progenitor stage. SMAD4 knockdown (KD) suppressed the production of these BMP inhibitors by SCZ GPCs and rescued normal astrocytic differentiation. In addition, the BMP-regulated transcriptional repressor REST was upregulated in SCZ GPCs, and its KD similarly restored normal glial differentiation. REST KD also rescued potassium-transport-associated gene expression and K+ uptake, which were otherwise deficient in SCZ glia. These data suggest that the glial differentiation defect in childhood-onset SCZ, and its attendant disruption in K+ homeostasis, may be rescued by targeting BMP/SMAD4- and REST-dependent transcription.
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224
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Roman C, Egert L, Di Benedetto B. Astrocytic-neuronal crosstalk gets jammed: Alternative perspectives on the onset of neuropsychiatric disorders. Eur J Neurosci 2020; 54:5717-5729. [PMID: 32644273 DOI: 10.1111/ejn.14900] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 06/09/2020] [Accepted: 07/03/2020] [Indexed: 12/12/2022]
Abstract
Investigating interactions of glia cells and synapses during development and in adulthood is the focus of several research programmes which aim at understanding the neurobiology of brain physiological and pathological processes. Both glia-specific released and membrane-bound proteins play essential roles in the development, maintenance and functionality of synaptic connections. Alterations in synaptic contacts in specific brain areas are hallmarks of several brain diseases, such as major depressive disorder, autism spectrum disorder and schizophrenia. Thus, a deeper knowledge about putative astrocyte dysfunctions which might affect the synaptic compartment is warranted to improve treatment options. Here, we present the latest advances about the role of glia cells in orchestrating the arrangement of synapses and neuronal networks in physiological and pathological states. We specifically focus on the role of astrocytes in the phagocytosis of neuronal synapses as a novel mechanism which drives the refinement of neuronal circuits and might be affected in pathological conditions. Finally, we propose this astrocyte-dependent mechanism as a putative alternative target of pharmacological interventions for the treatment of brain disorders.
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Affiliation(s)
- Celia Roman
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Luisa Egert
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany
| | - Barbara Di Benedetto
- Department of Psychiatry and Psychotherapy, University of Regensburg, Regensburg, Germany.,Regensburg Center of Neuroscience, University of Regensburg, Regensburg, Germany
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225
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Taylor X, Cisternas P, You Y, You Y, Xiang S, Marambio Y, Zhang J, Vidal R, Lasagna-Reeves CA. A1 reactive astrocytes and a loss of TREM2 are associated with an early stage of pathology in a mouse model of cerebral amyloid angiopathy. J Neuroinflammation 2020; 17:223. [PMID: 32711525 PMCID: PMC7382050 DOI: 10.1186/s12974-020-01900-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 07/15/2020] [Indexed: 02/07/2023] Open
Abstract
Background Cerebral amyloid angiopathy (CAA) is typified by the cerebrovascular deposition of amyloid. The mechanisms underlying the contribution of CAA to neurodegeneration are not currently understood. Although CAA is highly associated with the accumulation of amyloid beta (Aβ), other amyloids are known to associate with the vasculature. Alzheimer’s disease (AD) is characterized by parenchymal Aβ deposition, intracellular accumulation of tau, and significant neuroinflammation. CAA increases with age and is present in 85–95% of individuals with AD. A substantial amount of research has focused on understanding the connection between parenchymal amyloid and glial activation and neuroinflammation, while associations between vascular amyloid pathology and glial reactivity remain understudied. Methods Here, we dissect the glial and immune responses associated with early-stage CAA with histological, biochemical, and gene expression analyses in a mouse model of familial Danish dementia (FDD), a neurodegenerative disease characterized by the vascular accumulation of Danish amyloid (ADan). Findings observed in this CAA mouse model were complemented with primary culture assays. Results We demonstrate that early-stage CAA is associated with dysregulation in immune response networks and lipid processing, severe astrogliosis with an A1 astrocytic phenotype, and decreased levels of TREM2 with no reactive microgliosis. Our results also indicate how cholesterol accumulation and ApoE are associated with vascular amyloid deposits at the early stages of pathology. We also demonstrate A1 astrocytic mediation of TREM2 and microglia homeostasis. Conclusion The initial glial response associated with early-stage CAA is characterized by the upregulation of A1 astrocytes without significant microglial reactivity. Gene expression analysis revealed that several AD risk factors involved in immune response and lipid processing may also play a preponderant role in CAA. This study contributes to the increasing evidence that brain cholesterol metabolism, ApoE, and TREM2 signaling are major players in the pathogenesis of AD-related dementias, including CAA. Understanding the basis for possible differential effects of glial response, ApoE, and TREM2 signaling on parenchymal plaques versus vascular amyloid deposits provides important insight for developing future therapeutic interventions.
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Affiliation(s)
- Xavier Taylor
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Neurosciences Research Building 214G, 320 West 15th Street, Indianapolis, IN, 46202, USA.,Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Pablo Cisternas
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Neurosciences Research Building 214G, 320 West 15th Street, Indianapolis, IN, 46202, USA.,Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Yanwen You
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Neurosciences Research Building 214G, 320 West 15th Street, Indianapolis, IN, 46202, USA.,Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Yingjian You
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Neurosciences Research Building 214G, 320 West 15th Street, Indianapolis, IN, 46202, USA.,Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Shunian Xiang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Yamil Marambio
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Neurosciences Research Building 214G, 320 West 15th Street, Indianapolis, IN, 46202, USA.,Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Jie Zhang
- Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Ruben Vidal
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Neurosciences Research Building 214G, 320 West 15th Street, Indianapolis, IN, 46202, USA.,Department of Pathology and Laboratory Medicine, Indiana University School of Medicine, Indianapolis, IN, 46202, USA
| | - Cristian A Lasagna-Reeves
- Stark Neurosciences Research Institute, Indiana University School of Medicine, Neurosciences Research Building 214G, 320 West 15th Street, Indianapolis, IN, 46202, USA. .,Department of Anatomy, Cell Biology, & Physiology, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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226
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Jiang D, Gong F, Ge X, Lv C, Huang C, Feng S, Zhou Z, Rong Y, Wang J, Ji C, Chen J, Zhao W, Fan J, Liu W, Cai W. Neuron-derived exosomes-transmitted miR-124-3p protect traumatically injured spinal cord by suppressing the activation of neurotoxic microglia and astrocytes. J Nanobiotechnology 2020; 18:105. [PMID: 32711535 PMCID: PMC7382861 DOI: 10.1186/s12951-020-00665-8] [Citation(s) in RCA: 131] [Impact Index Per Article: 32.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 07/20/2020] [Indexed: 12/22/2022] Open
Abstract
Background Spinal cord injury (SCI) is a catastrophic injury that can cause irreversible motor dysfunction with high disability. Exosomes participate in the transport of miRNAs and play an essential role in intercellular communication via transfer of genetic material. However, the miRNAs in exosomes which derived from neurons, and the underlying mechanisms by which they contribute to SCI remain unknown. Methods A contusive in vivo SCI model and a series of in vitro experiments were carried out to explore the therapeutic effects of exosomes. Then, a miRNA microarray analysis and rescue experiments were performed to confirm the role of neuron-derived exosomal miRNA in SCI. Western blot, luciferase activity assay, and RNA-ChIP were used to investigate the underlying mechanisms. Results The results indicated that neuron-derived exosomes promoted functional behavioral recovery by suppressing the activation of M1 microglia and A1 astrocytes in vivo and in vitro. A miRNA array showed miR-124-3p to be the most enriched in neuron-derived exosomes. MYH9 was identified as the target downstream gene of miR-124-3p. A series of experiments were used to confirm the miR-124-3p/MYH9 axis. Finally, it was found that PI3K/AKT/NF-κB signaling cascades may be involved in the modulation of microglia by exosomal miR-124-3p. Conclusion A combination of miRNAs and neuron-derived exosomes may be a promising, minimally invasive approach for the treatment of SCI.
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Affiliation(s)
- Dongdong Jiang
- Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Fangyi Gong
- Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Xuhui Ge
- Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Chengtang Lv
- Department of Orthopaedics, Yancheng Third People's Hospital, Yancheng, 224000, Jiangsu, China
| | - Chenyu Huang
- Department of Orthopaedics, Nanjing First Hospital, Nanjing Medical University, Nanjing, 210006, Jiangsu, China
| | - Shuang Feng
- Department of Encephalopathy, The Third Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, 210001, Jiangsu, China
| | - Zheng Zhou
- Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Yuluo Rong
- Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Jiaxing Wang
- Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Chengyue Ji
- Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Jian Chen
- Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China
| | - Wene Zhao
- Department of Analytical & Testing Center, Nanjing Medical University, Nanjing, 211666, Jiangsu, China
| | - Jin Fan
- Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China.
| | - Wei Liu
- Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China.
| | - Weihua Cai
- Department of Orthopaedics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, Jiangsu, China.
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227
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Xu W, Löwel S, Schlüter OM. Silent Synapse-Based Mechanisms of Critical Period Plasticity. Front Cell Neurosci 2020; 14:213. [PMID: 32765222 PMCID: PMC7380267 DOI: 10.3389/fncel.2020.00213] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 06/17/2020] [Indexed: 01/08/2023] Open
Abstract
Critical periods are postnatal, restricted time windows of heightened plasticity in cortical neural networks, during which experience refines principal neuron wiring configurations. Here, we propose a model with two distinct types of synapses, innate synapses that establish rudimentary networks with innate function, and gestalt synapses that govern the experience-dependent refinement process. Nascent gestalt synapses are constantly formed as AMPA receptor-silent synapses which are the substrates for critical period plasticity. Experience drives the unsilencing and stabilization of gestalt synapses, as well as synapse pruning. This maturation process changes synapse patterning and consequently the functional architecture of cortical excitatory networks. Ocular dominance plasticity (ODP) in the primary visual cortex (V1) is an established experimental model for cortical plasticity. While converging evidence indicates that the start of the critical period for ODP is marked by the maturation of local inhibitory circuits, recent results support our model that critical periods end through the progressive maturation of gestalt synapses. The cooperative yet opposing function of two postsynaptic signaling scaffolds of excitatory synapses, PSD-93 and PSD-95, governs the maturation of gestalt synapses. Without those proteins, networks do not progress far beyond their innate functionality, resulting in rather impaired perception. While cortical networks remain malleable throughout life, the cellular mechanisms and the scope of critical period and adult plasticity differ. Critical period ODP is initiated with the depression of deprived eye responses in V1, whereas adult ODP is characterized by an initial increase in non-deprived eye responses. Our model proposes the gestalt synapse-based mechanism for critical period ODP, and also predicts a different mechanism for adult ODP based on the sparsity of nascent gestalt synapses at that age. Under our model, early life experience shapes the boundaries (the gestalt) for network function, both for its optimal performance as well as for its pathological state. Thus, reintroducing nascent gestalt synapses as plasticity substrates into adults may improve the network gestalt to facilitate functional recovery.
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Affiliation(s)
- Weifeng Xu
- Department of Neuroscience, Brown University, Providence, RI, United States
- Carney Institute for Brain Science, Brown University, Providence, RI, United States
| | - Siegrid Löwel
- Department of Systems Neuroscience, Johann-Friedrich-Blumenbach Institute for Zoology & Anthropology, University of Göttingen, Göttingen, Germany
- Campus Institute for Dynamics of Biological Networks, University of Göttingen, Göttingen, Germany
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
| | - Oliver M. Schlüter
- Collaborative Research Center 889, University of Göttingen, Göttingen, Germany
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, PA, United States
- Department of Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
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228
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Matejuk A, Ransohoff RM. Crosstalk Between Astrocytes and Microglia: An Overview. Front Immunol 2020; 11:1416. [PMID: 32765501 PMCID: PMC7378357 DOI: 10.3389/fimmu.2020.01416] [Citation(s) in RCA: 202] [Impact Index Per Article: 50.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Accepted: 06/02/2020] [Indexed: 12/19/2022] Open
Abstract
Based on discoveries enabled by new technologies and analysis using novel computational tools, neuroscience can be re-conceived in terms of information exchange in dense networks of intercellular connections rather than in the context of individual populations, such as glia or neurons. Cross-talk between neurons and microglia or astrocytes has been addressed, however, the manner in which non-neuronal cells communicate and interact remains less well-understood. We review this intriguing crosstalk among CNS cells, focusing on astrocytes and microglia and how it contributes to brain development and neurodegenerative diseases. The goal of studying these intercellular communications is to promote our ability to combat incurable neurological disorders.
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Affiliation(s)
- Agata Matejuk
- Department of Immunology, Collegium Medicum, University of Zielona Góra, Zielona Góra, Poland
| | - Richard M Ransohoff
- Third Rock Ventures, Boston, MA, United States.,Department of Cell Biology, Harvard Medical School, Boston, MA, United States
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229
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Martinez-Lozada Z, Robinson MB. Reciprocal communication between astrocytes and endothelial cells is required for astrocytic glutamate transporter 1 (GLT-1) expression. Neurochem Int 2020; 139:104787. [PMID: 32650029 DOI: 10.1016/j.neuint.2020.104787] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 05/15/2020] [Accepted: 06/14/2020] [Indexed: 12/12/2022]
Abstract
Astrocytes have diverse functions that are supported by their anatomic localization between neurons and blood vessels. One of these functions is the clearance of extracellular glutamate. Astrocytes clear glutamate using two Na+-dependent glutamate transporters, GLT-1 (also called EAAT2) and GLAST (also called EAAT1). GLT-1 expression increases during synaptogenesis and is a marker of astrocyte maturation. Over 20 years ago, several groups demonstrated that astrocytes in culture express little or no GLT-1 and that neurons induce expression. We recently demonstrated that co-culturing endothelia with mouse astrocytes also induced expression of GLT-1 and GLAST. These increases were blocked by an inhibitor of γ-secretase. This and other observations are consistent with the hypothesis that Notch signaling is required, but the ligands involved were not identified. In the present study, we used rat astrocyte cultures to further define the mechanisms by which endothelia induce expression of GLT-1 and GLAST. We found that co-cultures of astrocytes and endothelia express higher levels of GLT-1 and GLAST protein and mRNA. That endothelia activate Hes5, a transcription factor target of Notch, in astrocytes. Using recombinant Notch ligands, anti-Notch ligand neutralizing antibodies, and shRNAs, we provide evidence that both Dll1 and Dll4 contribute to endothelia-dependent regulation of GLT-1. We also provide evidence that astrocytes secrete a factor(s) that induces expression of Dll4 in endothelia and that this effect is required for Notch-dependent induction of GLT-1. Together these studies indicate that reciprocal communication between astrocytes and endothelia is required for appropriate astrocyte maturation and that endothelia likely deploy additional non-Notch signals to induce GLT-1.
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Affiliation(s)
- Zila Martinez-Lozada
- Departments of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA, USA, 19104-4318
| | - Michael B Robinson
- Departments of Pediatrics, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA, USA, 19104-4318; Systems Pharmacology and Translational Therapeutics, Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA, 19104-4318, USA.
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230
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Enright HA, Lam D, Sebastian A, Sales AP, Cadena J, Hum NR, Osburn JJ, Peters SKG, Petkus B, Soscia DA, Kulp KS, Loots GG, Wheeler EK, Fischer NO. Functional and transcriptional characterization of complex neuronal co-cultures. Sci Rep 2020; 10:11007. [PMID: 32620908 PMCID: PMC7335084 DOI: 10.1038/s41598-020-67691-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 06/08/2020] [Indexed: 12/03/2022] Open
Abstract
Brain-on-a-chip systems are designed to simulate brain activity using traditional in vitro cell culture on an engineered platform. It is a noninvasive tool to screen new drugs, evaluate toxicants, and elucidate disease mechanisms. However, successful recapitulation of brain function on these systems is dependent on the complexity of the cell culture. In this study, we increased cellular complexity of traditional (simple) neuronal cultures by co-culturing with astrocytes and oligodendrocyte precursor cells (complex culture). We evaluated and compared neuronal activity (e.g., network formation and maturation), cellular composition in long-term culture, and the transcriptome of the two cultures. Compared to simple cultures, neurons from complex co-cultures exhibited earlier synapse and network development and maturation, which was supported by localized synaptophysin expression, up-regulation of genes involved in mature neuronal processes, and synchronized neural network activity. Also, mature oligodendrocytes and reactive astrocytes were only detected in complex cultures upon transcriptomic analysis of age-matched cultures. Functionally, the GABA antagonist bicuculline had a greater influence on bursting activity in complex versus simple cultures. Collectively, the cellular complexity of brain-on-a-chip systems intrinsically develops cell type-specific phenotypes relevant to the brain while accelerating the maturation of neuronal networks, important features underdeveloped in traditional cultures.
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Affiliation(s)
- Heather A Enright
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.
| | - Doris Lam
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Aimy Sebastian
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Ana Paula Sales
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Jose Cadena
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Nicholas R Hum
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.,University of California, Merced, School of Natural Sciences, Merced, CA, USA
| | - Joanne J Osburn
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Sandra K G Peters
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Bryan Petkus
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - David A Soscia
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Kristen S Kulp
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Gabriela G Loots
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.,University of California, Merced, School of Natural Sciences, Merced, CA, USA
| | - Elizabeth K Wheeler
- Engineering Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA
| | - Nicholas O Fischer
- Physical and Life Sciences Directorate, Lawrence Livermore National Laboratory, Livermore, CA, USA.
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231
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Potokar M, Morita M, Wiche G, Jorgačevski J. The Diversity of Intermediate Filaments in Astrocytes. Cells 2020; 9:E1604. [PMID: 32630739 PMCID: PMC7408014 DOI: 10.3390/cells9071604] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Revised: 06/26/2020] [Accepted: 07/01/2020] [Indexed: 01/02/2023] Open
Abstract
Despite the remarkable complexity of the individual neuron and of neuronal circuits, it has been clear for quite a while that, in order to understand the functioning of the brain, the contribution of other cell types in the brain have to be accounted for. Among glial cells, astrocytes have multiple roles in orchestrating neuronal functions. Their communication with neurons by exchanging signaling molecules and removing molecules from extracellular space takes place at several levels and is governed by different cellular processes, supported by multiple cellular structures, including the cytoskeleton. Intermediate filaments in astrocytes are emerging as important integrators of cellular processes. Astrocytes express five types of intermediate filaments: glial fibrillary acidic protein (GFAP); vimentin; nestin; synemin; lamins. Variability, interactions with different cellular structures and the particular roles of individual intermediate filaments in astrocytes have been studied extensively in the case of GFAP and vimentin, but far less attention has been given to nestin, synemin and lamins. Similarly, the interplay between different types of cytoskeleton and the interaction between the cytoskeleton and membranous structures, which is mediated by cytolinker proteins, are understudied in astrocytes. The present review summarizes the basic properties of astrocytic intermediate filaments and of other cytoskeletal macromolecules, such as cytolinker proteins, and describes the current knowledge of their roles in normal physiological and pathological conditions.
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Affiliation(s)
- Maja Potokar
- Laboratory of Neuroendocrinology – Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
- Celica BIOMEDICAL, 1000 Ljubljana, Slovenia;
| | - Mitsuhiro Morita
- Department of Biology, Kobe University Graduate School of Science, Kobe 657-8501, Japan;
| | - Gerhard Wiche
- Celica BIOMEDICAL, 1000 Ljubljana, Slovenia;
- Department of Biochemistry and Cell Biology, Max F. Perutz Laboratories, University of Vienna, 1030 Vienna, Austria
| | - Jernej Jorgačevski
- Laboratory of Neuroendocrinology – Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, 1000 Ljubljana, Slovenia;
- Celica BIOMEDICAL, 1000 Ljubljana, Slovenia;
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232
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Kiyoshi C, Tedeschi A. Axon growth and synaptic function: A balancing act for axonal regeneration and neuronal circuit formation in CNS trauma and disease. Dev Neurobiol 2020; 80:277-301. [PMID: 32902152 PMCID: PMC7754183 DOI: 10.1002/dneu.22780] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 08/29/2020] [Accepted: 08/31/2020] [Indexed: 12/13/2022]
Abstract
Axons in the adult mammalian central nervous system (CNS) fail to regenerate inside out due to intrinsic and extrinsic neuronal determinants. During CNS development, axon growth, synapse formation, and function are tightly regulated processes allowing immature neurons to effectively grow an axon, navigate toward target areas, form synaptic contacts and become part of information processing networks that control behavior in adulthood. Not only immature neurons are able to precisely control the expression of a plethora of genes necessary for axon extension and pathfinding, synapse formation and function, but also non-neuronal cells such as astrocytes and microglia actively participate in sculpting the nervous system through refinement, consolidation, and elimination of synaptic contacts. Recent evidence indicates that a balancing act between axon regeneration and synaptic function may be crucial for rebuilding functional neuronal circuits after CNS trauma and disease in adulthood. Here, we review the role of classical and new intrinsic and extrinsic neuronal determinants in the context of CNS development, injury, and disease. Moreover, we discuss strategies targeting neuronal and non-neuronal cell behaviors, either alone or in combination, to promote axon regeneration and neuronal circuit formation in adulthood.
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Affiliation(s)
- Conrad Kiyoshi
- Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, OH 43210, USA
| | - Andrea Tedeschi
- Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, OH 43210, USA
- Discovery Theme on Chronic Brain Injury, The Ohio State University, Columbus, OH 43210, USA
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233
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Wrede AH, McNamara MC, Baldwin R, Luo J, Montazami R, Kanthasamy A, Hashemi NN. Characterization of Astrocytic Response after Experiencing Cavitation In Vitro. GLOBAL CHALLENGES (HOBOKEN, NJ) 2020; 4:1900014. [PMID: 32642072 PMCID: PMC7330500 DOI: 10.1002/gch2.201900014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 05/06/2020] [Indexed: 06/11/2023]
Abstract
When a traumatic brain injury (TBI) occurs, low-pressure regions inside the skull can cause vapor contents in the cerebral spinal fluid (CSF) to expand and collapse, a phenomenon known as cavitation. When these microbubbles (MBs) collapse, shock waves are radiated outward and are known to damage surrounding materials in other applications, like the steel foundation of boat propellers, so it is alarming to realize the damage that cavitation inflicts on vulnerable brain tissue. Using cell-laden microfibers, the longitudinal morphological response that mouse astrocytes have to surrounding cavitation in vitro is visually analyzed. Astrocytic damage is evident immediately after cavitation when compared to a control sample, as their processes retract. Forty-eight hours later, the astrocytes appeared to spread across the fibers, as normal. This study also analyzes the gene expression changes that occur post-cavitation via quantitative polymerase chain reaction (qPCR) methods. After cavitation a number of pro-inflammatory genes are upregulated, including TNFα, IL-1β, C1q, Serping1, NOS1, IL-6, and JMJD3. Taken together, these results confirm that surrounding cavitation is detrimental to astrocytic function, and yield opportunities to further the understanding of how protective headgear can minimize or eliminate the occurrence of cavitation.
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Affiliation(s)
- Alex H. Wrede
- Department of Mechanical EngineeringIowa State UniversityAmesIA50011USA
| | | | - Rodger Baldwin
- Department of Mechanical EngineeringIowa State UniversityAmesIA50011USA
| | - Jie Luo
- Department of Biomedical SciencesIowa State UniversityAmesIA50011USA
| | - Reza Montazami
- Department of Mechanical EngineeringIowa State UniversityAmesIA50011USA
| | | | - Nicole N. Hashemi
- Department of Mechanical EngineeringIowa State UniversityAmesIA50011USA
- Department of Biomedical SciencesIowa State UniversityAmesIA50011USA
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234
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Lee YF, Gerashchenko D, Timofeev I, Bacskai BJ, Kastanenka KV. Slow Wave Sleep Is a Promising Intervention Target for Alzheimer's Disease. Front Neurosci 2020; 14:705. [PMID: 32714142 PMCID: PMC7340158 DOI: 10.3389/fnins.2020.00705] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 06/11/2020] [Indexed: 12/22/2022] Open
Abstract
Alzheimer's disease (AD) is the major cause of dementia, characterized by the presence of amyloid-beta plaques and neurofibrillary tau tangles. Plaques and tangles are associated with sleep-wake cycle disruptions, including the disruptions in non-rapid eye movement (NREM) slow wave sleep (SWS). Alzheimer's patients spend less time in NREM sleep and exhibit decreased slow wave activity (SWA). Consistent with the critical role of SWS in memory consolidation, reduced SWA is associated with impaired memory consolidation in AD patients. The aberrant SWA can be modeled in transgenic mouse models of amyloidosis and tauopathy. Animal models exhibited slow wave impairments early in the disease progression, prior to the deposition of amyloid-beta plaques, however, in the presence of abundant oligomeric amyloid-beta. Optogenetic rescue of SWA successfully halted the amyloid accumulation and restored intraneuronal calcium levels in mice. On the other hand, optogenetic acceleration of slow wave frequency exacerbated amyloid deposition and disrupted neuronal calcium homeostasis. In this review, we summarize the evidence and the mechanisms underlying the existence of a positive feedback loop between amyloid/tau pathology and SWA disruptions that lead to further accumulations of amyloid and tau in AD. Moreover, since SWA disruptions occur prior to the plaque deposition, SWA disruptions may provide an early biomarker for AD. Finally, we propose that therapeutic targeting of SWA in AD might lead to an effective treatment for Alzheimer's patients.
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Affiliation(s)
- Yee Fun Lee
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States
- Department of Anatomy and Neurobiology, Boston University School of Medicine, Boston, MA, United States
| | - Dmitry Gerashchenko
- Harvard Medical School/VA Boston Healthcare System, West Roxbury, MA, United States
| | - Igor Timofeev
- Department of Psychiatry and Neuroscience, School of Medicine, Université Laval, Québec, QC, Canada
- CERVO Brain Research Center, Québec, QC, Canada
| | - Brian J. Bacskai
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States
| | - Ksenia V. Kastanenka
- Department of Neurology, MassGeneral Institute of Neurodegenerative Diseases, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, United States
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235
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Ibrahim AM, Pottoo FH, Dahiya ES, Khan FA, Kumar JBS. Neuron‐glia interactions: Molecular basis of alzheimer’s disease and applications of neuroproteomics. Eur J Neurosci 2020; 52:2931-2943. [DOI: 10.1111/ejn.14838] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2020] [Revised: 04/30/2020] [Accepted: 05/18/2020] [Indexed: 12/30/2022]
Affiliation(s)
- Abdallah Mohammad Ibrahim
- Fundamentals of Nursing Department College of Nursing Imam Abdulrahman Bin Faisal University Dammam Saudi Arabia
| | - Faheem Hyder Pottoo
- Department of Pharmacology College of Clinical Pharmacy Imam Abdulrahman Bin Faisal University Dammam Saudi Arabia
| | - Ekta Singh Dahiya
- National Institute of Stroke and Applied Neurosciences (NISAN) Auckland University of Technology Auckland New‐Zealand
| | - Firdos Alam Khan
- Department of Stem Cell Research Institute for Research and Medical Consultations Imam Abdulrahman Bin Faisal University Dammam Saudi Arabia
| | - J. B. Senthil Kumar
- Special centre for Molecular Medicine Jawaharlal Nehru University New‐Delhi India
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236
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Bres EE, Safina D, Müller J, Bedner P, Yang H, Helluy X, Shchyglo O, Jansen S, Mark MD, Esser A, Steinhäuser C, Herlitze S, Pietrzik CU, Sirko S, Manahan-Vaughan D, Faissner A. Lipoprotein receptor loss in forebrain radial glia results in neurological deficits and severe seizures. Glia 2020; 68:2517-2549. [PMID: 32579270 DOI: 10.1002/glia.23869] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2019] [Revised: 05/19/2020] [Accepted: 05/22/2020] [Indexed: 02/06/2023]
Abstract
The Alzheimer disease-associated multifunctional low-density lipoprotein receptor-related protein-1 is expressed in the brain. Recent studies uncovered a role of this receptor for the appropriate functioning of neural stem cells, oligodendrocytes, and neurons. The constitutive knock-out (KO) of the receptor is embryonically lethal. To unravel the receptors' role in the developing brain we generated a mouse mutant by specifically targeting radial glia stem cells of the dorsal telencephalon. The low-density lipoprotein receptor-related protein-1 lineage-restricted KO female and male mice, in contrast to available models, developed a severe neurological phenotype with generalized seizures during early postnatal development. The mechanism leading to a buildup of hyperexcitability and emergence of seizures was traced to a failure in adequate astrocyte development and deteriorated postsynaptic density integrity. The detected impairments in the astrocytic lineage: precocious maturation, reactive gliosis, abolished tissue plasminogen activator uptake, and loss of functionality emphasize the importance of this glial cell type for synaptic signaling in the developing brain. Together, the obtained results highlight the relevance of astrocytic low-density lipoprotein receptor-related protein-1 for glutamatergic signaling in the context of neuron-glia interactions and stage this receptor as a contributing factor for epilepsy.
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Affiliation(s)
- Ewa E Bres
- Department of Cell Morphology and Molecular Neurobiology, Ruhr University Bochum, Bochum, Germany.,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Dina Safina
- Department of Cell Morphology and Molecular Neurobiology, Ruhr University Bochum, Bochum, Germany.,International Graduate School of Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Julia Müller
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Honghong Yang
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
| | - Xavier Helluy
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany.,Department of Psychology, Institute of Cognitive Neuroscience, Biopsychology, Ruhr University Bochum, Bochum, Germany
| | - Olena Shchyglo
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
| | - Stephan Jansen
- Department of Neurophysiology, Medical Faculty, Ruhr University Bochum, Bochum, Germany
| | - Melanie D Mark
- Behavioral Neuroscience, Ruhr University Bochum, Bochum, Germany
| | | | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Stefan Herlitze
- Department of General Zoology and Neurobiology, Ruhr University Bochum, Bochum, Germany
| | - Claus U Pietrzik
- Institute of Pathobiochemistry, University Medical Center of the Johannes Gutenberg University Mainz, Mainz, Germany
| | - Swetlana Sirko
- Department of Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians University, Planegg-Martinsried, Germany.,Institute for Stem Cell Research, Helmholtz Zentrum Munich, Neuherberg, Germany
| | | | - Andreas Faissner
- Department of Cell Morphology and Molecular Neurobiology, Ruhr University Bochum, Bochum, Germany
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237
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Meloni M, Morgado J, Garcia M, Stipursky J, Gomes FCA. Cryopreserved astrocytes maintain biological properties: Support of neuronal survival and differentiation. J Neurosci Methods 2020; 343:108806. [PMID: 32574642 DOI: 10.1016/j.jneumeth.2020.108806] [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: 05/07/2020] [Revised: 06/09/2020] [Accepted: 06/10/2020] [Indexed: 10/24/2022]
Abstract
BACKGROUND Astrocytes, one of the main glial cell types, play critical roles in the central nervous system (CNS) development and function, including support of neuronal survival and differentiation, blood brain barrier formation, synapse homeostasis and injury response. Cell isolation and culture techniques have been proved to be a powerful tool to study astrocyte physiology and function. Due to financial constraints and rigid biosafety and ethics rules to use animal models, freezing techniques and the creation of cell banks emerged as alternatives to optimize the use of experimental animals. One of the main challenges, however, of these techniques is to guarantee that conserved cells keep their biological properties. NEW METHOD In this work, we characterized morphologically and functionally murine secondary astrocyte cultures that have been submitted to freezing/thawing procedures. RESULTS Morphological characterization of SAC (secondary astrocyte culture) and SFAC (secondary frozen-astrocyte culture) did not reveal significant differences on astrocyte morphology, confluence time and cell number along culture period. Functionally, SAC and SFAC did not reveal differences in their potential to support neuronal survival, maturation, neuritogenesis and synapse formation. CONCLUSIONS Our results suggest that murine astrocytes that are submitted to freezing/thawing procedure maintain morphological and functional characteristics when compared with non-frozen astrocytes. Thus, this methodological approach is a valuable tool for in vitro research and might allow experimental optimization and reduction of animal use.
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Affiliation(s)
- Marcelo Meloni
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil; Programa de Pós-Graduação Formação de Pesquisadores, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Juliana Morgado
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Matheus Garcia
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Joice Stipursky
- Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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238
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Jin S, Kim KK, Park BS, Kim DH, Jeong B, Kang D, Lee TH, Park JW, Kim JG, Lee BJ. Function of astrocyte MyD88 in high-fat-diet-induced hypothalamic inflammation. J Neuroinflammation 2020; 17:195. [PMID: 32560726 PMCID: PMC7304177 DOI: 10.1186/s12974-020-01846-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/19/2020] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND A growing body of evidence shows that hypothalamic inflammation is an important factor in the initiation of obesity. In particular, reactive gliosis accompanied by inflammatory responses in the hypothalamus are pivotal cellular events that elicit metabolic abnormalities. In this study, we examined whether MyD88 signaling in hypothalamic astrocytes controls reactive gliosis and inflammatory responses, thereby contributing to the pathogenesis of obesity. METHODS To analyze the role of astrocyte MyD88 in obesity pathogenesis, we used astrocyte-specific Myd88 knockout (KO) mice fed a high-fat diet (HFD) for 16 weeks or injected with saturated free fatty acids. Astrocyte-specific gene expression in the hypothalamus was determined using real-time PCR with mRNA purified by the Ribo-Tag system. Immunohistochemistry was used to detect the expression of glial fibrillary acidic protein, ionized calcium-binding adaptor molecule 1, phosphorylated signal transducer and activator of transcription 3, and α-melanocyte-stimulating hormone in the hypothalamus. Animals' energy expenditure was measured using an indirect calorimetry system. RESULTS The astrocyte-specific Myd88 KO mice displayed ameliorated hypothalamic reactive gliosis and inflammation induced by injections of saturated free fatty acids and a long-term HFD. Accordingly, the KO mice were resistant to long-term HFD-induced obesity and showed an improvement in HFD-induced leptin resistance. CONCLUSIONS These results suggest that MyD88 in hypothalamic astrocytes is a critical molecular unit for obesity pathogenesis that acts by mediating HFD signals for reactive gliosis and inflammation.
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Affiliation(s)
- Sungho Jin
- Department of Biological Sciences, University of Ulsan, Ulsan, 44610, Republic of Korea
- Present address: Department of Cellular and Molecular Physiology, Yale University School of Medicine, New Haven, CT, 06520, USA
| | - Kwang Kon Kim
- Department of Biological Sciences, University of Ulsan, Ulsan, 44610, Republic of Korea
| | - Byong Seo Park
- Department of Biological Sciences, University of Ulsan, Ulsan, 44610, Republic of Korea
- Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon, 22012, Republic of Korea
| | - Dong Hee Kim
- Department of Biological Sciences, University of Ulsan, Ulsan, 44610, Republic of Korea
| | - Bora Jeong
- Department of Biological Sciences, University of Ulsan, Ulsan, 44610, Republic of Korea
| | - Dasol Kang
- Department of Biological Sciences, University of Ulsan, Ulsan, 44610, Republic of Korea
| | - Tae Hwan Lee
- Department of Biological Sciences, University of Ulsan, Ulsan, 44610, Republic of Korea
| | - Jeong Woo Park
- Department of Biological Sciences, University of Ulsan, Ulsan, 44610, Republic of Korea
| | - Jae Geun Kim
- Division of Life Sciences, College of Life Sciences and Bioengineering, Incheon National University, Incheon, 22012, Republic of Korea.
| | - Byung Ju Lee
- Department of Biological Sciences, University of Ulsan, Ulsan, 44610, Republic of Korea.
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239
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Zhang Y, Luan D, Liu Y, Li H, Dong J, Zhang X, Yuan L, Zhong Z, Jiang L, Li X, Ye M, Tong J. Helicid Reverses Lipopolysaccharide-Induced Inflammation and Promotes GDNF Levels in C6 Glioma Cells through Modulation of Prepronociceptin. Chem Biodivers 2020; 17:e2000063. [PMID: 32329965 DOI: 10.1002/cbdv.202000063] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 04/24/2020] [Indexed: 12/18/2022]
Abstract
Helicid suppresses inflammatory factors and protects nerve cells in the hippocampus of rats with depression, but the mechanisms underlying its protective effects are unclear at present. In this investigation, we conducted gene silencing, Helicid intervention and rescue experiments to explore the protective actions of PNOC, the prepronociceptin gene known to regulate inflammatory processes, and Helicid on a C6 cell model of inflammation induced by LPS. Collective data from Western blots, ELISA, immunofluorescence and flow cytometry experiments showed that PNOC silencing or administration of Helicid led to reduced inflammatory factor levels, oxidative stress and expression of glial fibrillary acidic protein (GFAP), along with increased glial cell lines-derived neurotrophic factor (GDNF) expression. Furthermore, expression of p-Akt in the Akt signaling pathway was increased. Interestingly, overexpression of PNOC in the Helicid treatment group partially reversed the Helicid-induced changes in the above biochemical indexes. Our collective results provide strong evidence of Helicid-mediated regulation of the Akt signaling pathway through PNOC to improve cell inflammation and oxidative stress.
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Affiliation(s)
| | - Di Luan
- Department of Neurology, The First Affiliated Hospital of Wannan Medical College, Wuhu, 241001, P. R. China
| | - Yanhao Liu
- Wannan Medical College, Wuhu, 241000, P. R. China
| | - Hongjin Li
- Wannan Medical College, Wuhu, 241000, P. R. China
| | - Jian Dong
- Wannan Medical College, Wuhu, 241000, P. R. China
| | | | - Lili Yuan
- Department of Neurology, The First Affiliated Hospital of Wannan Medical College, Wuhu, 241001, P. R. China
| | - Zhengling Zhong
- Department of Clinical Pharmacy, The First Affiliated Hospital of Wannan Medical College, Wuhu, 241001, P. R. China
| | - Lan Jiang
- Central Laboratory, The First Affiliated Hospital of Wannan Medical College, Wuhu, 241001, P. R. China
| | - Xuyi Li
- China Pharmaceutical University, Nanjing, 210009, P. R. China
| | - Mingquan Ye
- Wannan Medical College, Wuhu, 241000, P. R. China
| | - Jiucui Tong
- Wannan Medical College, Wuhu, 241000, P. R. China.,Department of Clinical Pharmacy, The First Affiliated Hospital of Wannan Medical College, Wuhu, 241001, P. R. China
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240
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Postmortem Studies of Neuroinflammation in Autism Spectrum Disorder: a Systematic Review. Mol Neurobiol 2020; 57:3424-3438. [DOI: 10.1007/s12035-020-01976-5] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Accepted: 06/02/2020] [Indexed: 02/06/2023]
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241
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Metformin regulates astrocyte reactivity in Parkinson's disease and normal aging. Neuropharmacology 2020; 175:108173. [PMID: 32497590 DOI: 10.1016/j.neuropharm.2020.108173] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 05/25/2020] [Accepted: 05/26/2020] [Indexed: 12/22/2022]
Abstract
Parkinson's disease (PD) is a neurodegenerative disease characterized by the progressive loss of dopaminergic neurons in the substantia nigra, leading to motor symptoms. Despite the remarkable improvements in the management of PD in recent decades, many patients remain significantly disabled. Metformin is a primary medication for the management of type 2 diabetes. We previously showed that co-treatment with metformin and 3,4-dihydroxyphenyl-l-alanine (l-DOPA) prevented the development of l-DOPA-induced dyskinesia in a 6-hydroxydopamine (6-OHDA)-lesioned animal model of PD. However, effects of metformin on PD- and aging-induced genes in reactive astrocytes remain unknown. In this study, we assessed the effect of metformin on motor function, neuroprotection, and reactive astrocytes in the 6-OHDA-induced PD animal model. In addition, the effects of metformin on the genes expressed by specific types of astrocytes were analyzed in PD model and aged mice. Here, we showed that metformin treatment effectively improves the motor symptoms in the 6-OHDA-induced PD mouse model, whereas metformin had no effect on tyrosine hydroxylase-positive neurons. The activation of AMPK and BDNF signaling pathways was induced by metformin treatment on the 6-OHDA-lesioned side of the striatum. Metformin treatment caused astrocytes to alter reactive genes in a PD animal model. Moreover, aging-induced genes in reactive astrocytes were effectively regulated or suppressed by metformin treatment. Taken together, these results suggest that metformin should be evaluated for the treatment of Parkinson's disease and related neurologic disorders characterized by astrocyte activation.
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242
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Felix L, Stephan J, Rose CR. Astrocytes of the early postnatal brain. Eur J Neurosci 2020; 54:5649-5672. [PMID: 32406559 DOI: 10.1111/ejn.14780] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 04/30/2020] [Accepted: 05/06/2020] [Indexed: 12/21/2022]
Abstract
In the rodent forebrain, the majority of astrocytes are generated during the early postnatal phase. Following differentiation, astrocytes undergo maturation which accompanies the development of the neuronal network. Neonate astrocytes exhibit a distinct morphology and domain size which differs to their mature counterparts. Moreover, many of the plasma membrane proteins prototypical for fully developed astrocytes are only expressed at low levels at neonatal stages. These include connexins and Kir4.1, which define the low membrane resistance and highly negative membrane potential of mature astrocytes. Newborn astrocytes moreover express only low amounts of GLT-1, a glutamate transporter critical later in development. Furthermore, they show specific differences in the properties and spatio-temporal pattern of intracellular calcium signals, resulting from differences in their repertoire of receptors and signalling pathways. Therefore, roles fulfilled by mature astrocytes, including ion and transmitter homeostasis, are underdeveloped in the young brain. Similarly, astrocytic ion signalling in response to neuronal activity, a process central to neuron-glia interaction, differs between the neonate and mature brain. This review describes the unique functional properties of astrocytes in the first weeks after birth and compares them to later stages of development. We conclude that with an immature neuronal network and wider extracellular space, astrocytic support might not be as demanding and critical compared to the mature brain. The delayed differentiation and maturation of astrocytes in the first postnatal weeks might thus reflect a reduced need for active, energy-consuming regulation of the extracellular space and a less tight control of glial feedback onto synaptic transmission.
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Affiliation(s)
- Lisa Felix
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Duesseldorf, Duesseldorf, Germany
| | - Jonathan Stephan
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Duesseldorf, Duesseldorf, Germany
| | - Christine R Rose
- Institute of Neurobiology, Faculty of Mathematics and Natural Sciences, Heinrich Heine University Duesseldorf, Duesseldorf, Germany
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243
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Stenovec M, Li B, Verkhratsky A, Zorec R. Astrocytes in rapid ketamine antidepressant action. Neuropharmacology 2020; 173:108158. [PMID: 32464133 DOI: 10.1016/j.neuropharm.2020.108158] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 04/27/2020] [Accepted: 05/20/2020] [Indexed: 12/14/2022]
Abstract
Ketamine, a general anaesthetic and psychotomimetic drug, exerts rapid, potent and long-lasting antidepressant effect, albeit the cellular and molecular mechanisms of this action are yet to be discovered. Besides targeting neuronal NMDARs fundamental for synaptic transmission, ketamine affects the function of astroglia the key homeostatic cells of the central nervous system that contribute to pathophysiology of psychiatric diseases including depression. Here we review studies revealing that (sub)anaesthetic doses of ketamine elevate intracellular cAMP concentration ([cAMP]i) in astrocytes, attenuate stimulus-evoked astrocyte calcium signalling, which regulates exocytotic secretion of gliosignalling molecules, and stabilize the vesicle fusion pore in a narrow configuration possibly hindering cargo discharge or vesicle recycling. Next we discuss how ketamine affects astroglial capacity to control extracellular K+ by reducing cytoplasmic mobility of vesicles delivering the inward rectifying potassium channel (Kir4.1) to the plasmalemma. Modified astroglial K+ buffering impacts upon neuronal excitability as demonstrated in the lateral habenula rat model of depression. Finally, we highlight the recent discovery that ketamine rapidly redistributes cholesterol in the plasmalemma of astrocytes, but not in fibroblasts nor in neuronal cells. This alteration of membrane structure may modulate a host of processes that synergistically contribute to ketamine's rapid and prominent antidepressant action.
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Affiliation(s)
- Matjaž Stenovec
- Celica BIOMEDICAL, Tehnološki Park 24, 1000, Ljubljana, Slovenia; Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia.
| | - Baoman Li
- Practical Teaching Centre, School of Forensic Medicine, China Medical University, Shenyang, People's Republic of China; Department of Poison Analysis, School of Forensic Medicine, China Medical University, Shenyang, China.
| | - Alexei Verkhratsky
- Celica BIOMEDICAL, Tehnološki Park 24, 1000, Ljubljana, Slovenia; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK; Achucarro Center for Neuroscience, IKERBASQUE, 48011, Bilbao, Spain.
| | - Robert Zorec
- Celica BIOMEDICAL, Tehnološki Park 24, 1000, Ljubljana, Slovenia; Laboratory of Neuroendocrinology-Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Zaloška 4, 1000, Ljubljana, Slovenia.
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244
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Nanostructural Diversity of Synapses in the Mammalian Spinal Cord. Sci Rep 2020; 10:8189. [PMID: 32424125 PMCID: PMC7235094 DOI: 10.1038/s41598-020-64874-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 04/21/2020] [Indexed: 11/25/2022] Open
Abstract
Functionally distinct synapses exhibit diverse and complex organisation at molecular and nanoscale levels. Synaptic diversity may be dependent on developmental stage, anatomical locus and the neural circuit within which synapses reside. Furthermore, astrocytes, which align with pre and post-synaptic structures to form ‘tripartite synapses’, can modulate neural circuits and impact on synaptic organisation. In this study, we aimed to determine which factors impact the diversity of excitatory synapses throughout the lumbar spinal cord. We used PSD95-eGFP mice, to visualise excitatory postsynaptic densities (PSDs) using high-resolution and super-resolution microscopy. We reveal a detailed and quantitative map of the features of excitatory synapses in the lumbar spinal cord, detailing synaptic diversity that is dependent on developmental stage, anatomical region and whether associated with VGLUT1 or VGLUT2 terminals. We report that PSDs are nanostructurally distinct between spinal laminae and across age groups. PSDs receiving VGLUT1 inputs also show enhanced nanostructural complexity compared with those receiving VGLUT2 inputs, suggesting pathway-specific diversity. Finally, we show that PSDs exhibit greater nanostructural complexity when part of tripartite synapses, and we provide evidence that astrocytic activation enhances PSD95 expression. Taken together, these results provide novel insights into the regulation and diversification of synapses across functionally distinct spinal regions and advance our general understanding of the ‘rules’ governing synaptic nanostructural organisation.
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245
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Gangopadhyay A, Mehta D, Chakrabartty S. A Spiking Neuron and Population Model Based on the Growth Transform Dynamical System. Front Neurosci 2020; 14:425. [PMID: 32477051 PMCID: PMC7235464 DOI: 10.3389/fnins.2020.00425] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 04/07/2020] [Indexed: 11/13/2022] Open
Abstract
In neuromorphic engineering, neural populations are generally modeled in a bottom-up manner, where individual neuron models are connected through synapses to form large-scale spiking networks. Alternatively, a top-down approach treats the process of spike generation and neural representation of excitation in the context of minimizing some measure of network energy. However, these approaches usually define the energy functional in terms of some statistical measure of spiking activity (ex. firing rates), which does not allow independent control and optimization of neurodynamical parameters. In this paper, we introduce a new spiking neuron and population model where the dynamical and spiking responses of neurons can be derived directly from a network objective or energy functional of continuous-valued neural variables like the membrane potential. The key advantage of the model is that it allows for independent control over three neuro-dynamical properties: (a) control over the steady-state population dynamics that encodes the minimum of an exact network energy functional; (b) control over the shape of the action potentials generated by individual neurons in the network without affecting the network minimum; and (c) control over spiking statistics and transient population dynamics without affecting the network minimum or the shape of action potentials. At the core of the proposed model are different variants of Growth Transform dynamical systems that produce stable and interpretable population dynamics, irrespective of the network size and the type of neuronal connectivity (inhibitory or excitatory). In this paper, we present several examples where the proposed model has been configured to produce different types of single-neuron dynamics as well as population dynamics. In one such example, the network is shown to adapt such that it encodes the steady-state solution using a reduced number of spikes upon convergence to the optimal solution. In this paper, we use this network to construct a spiking associative memory that uses fewer spikes compared to conventional architectures, while maintaining high recall accuracy at high memory loads.
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Affiliation(s)
- Ahana Gangopadhyay
- Department of Electrical and Systems Engineering, Washington University in St. Louis, St. Louis, MO, United States
| | - Darshit Mehta
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO, United States
| | - Shantanu Chakrabartty
- Department of Electrical and Systems Engineering, Washington University in St. Louis, St. Louis, MO, United States
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246
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Abstract
Astrocytes are morphologically complex, ubiquitous cells that are viewed as a homogeneous population tiling the entire central nervous system (CNS). However, this view has been challenged in the last few years with the availability of RNA sequencing, immunohistochemistry, electron microscopy, morphological reconstruction, and imaging data. These studies suggest that astrocytes represent a diverse population of cells and that they display brain area- and disease-specific properties and functions. In this review, we summarize these observations, emphasize areas where clear conclusions can be made, and discuss potential unifying themes. We also identify knowledge gaps that need to be addressed in order to exploit astrocyte diversity as a biological phenomenon of physiological relevance in the CNS. We thus provide a summary and a perspective on astrocyte diversity in the vertebrate CNS.
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Affiliation(s)
- Baljit S Khakh
- Departments of Physiology and Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, California 90095, USA;
| | - Benjamin Deneen
- Department of Neuroscience and Center for Cell and Gene Therapy, Baylor College of Medicine, Houston, Texas 77030, USA;
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247
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Shoneye T, Orrego AT, Jarvis R, Men Y, Chiang MSR, Yang Y. Differential Proliferation and Maturation of Subcortical Astrocytes During Postnatal Development. Front Neurosci 2020; 14:435. [PMID: 32457572 PMCID: PMC7225521 DOI: 10.3389/fnins.2020.00435] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Accepted: 04/09/2020] [Indexed: 01/24/2023] Open
Abstract
Astrocytes exhibit a region-dependent molecular and functional heterogeneity in the CNS. Although cortical astrocytes proliferate robustly during the first postnatal week and become proliferation quiescent, the temporal proliferation dynamics of astrocytes in subcortical regions during postnatal development remain essentially unknown. Whether subcortical astrocytes mature similarly to cortical astrocytes is also unexplored. In this current study, we examined proliferation of subcortical, especially hypothalamic, astrocytes during postnatal development using genetic labeling of astrocytes and pulse-chase EdU labeling of proliferating cells. While a lower number of proliferating astrocytes was found in the hypothalamus compared to cortex during the first postnatal week, astrocyte proliferation is much more active in hypothalamus than in cortex from P15 to P30 in both proliferating astrocyte density and percentage, indicating a persistent and distinct proliferation pattern of astrocytes in hypothalamus. This observation is further confirmed by Ki67 immunostaining with genetically or immunolabeled astrocytes in hypothalamus and cortex during P15-30. In addition, astrocytes in representative subcortical regions have a modest growth of their domain size and exhibit a significantly smaller domain size compared to cortical astrocytes at P30 when astrocytes have generally completed postnatal maturation. However, the expression of astrocyte-derived Sparc, an important synaptogenic inhibitor, is consistently higher in hypothalamic astrocytes than in cortical astrocytes throughout postnatal development. In summary, our study unveiled a distinct proliferation and maturation pattern of subcortical, especially hypothalamic, astrocytes during postnatal development.
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Affiliation(s)
- Temitope Shoneye
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | | | - Rachel Jarvis
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Yuqin Men
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Ming Sum R. Chiang
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
| | - Yongjie Yang
- Department of Neuroscience, Tufts University School of Medicine, Boston, MA, United States
- Graduate School of Biomedical Sciences, Tufts University, Boston, MA, United States
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248
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Isolation, culture, and downstream characterization of primary microglia and astrocytes from adult rodent brain and spinal cord. J Neurosci Methods 2020; 340:108742. [PMID: 32315669 DOI: 10.1016/j.jneumeth.2020.108742] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2020] [Revised: 04/10/2020] [Accepted: 04/14/2020] [Indexed: 01/01/2023]
Abstract
BACKGROUND Neuroimmunologists aspire to understand the interactions between neurons, microglia, and astrocytes in the CNS. To study these cells, researchers work with either immortalized cell lines or primary cells acquired from animal tissue. Primary cells reflect in vivo characteristics and functionality compared to immortalized cells; however, they are challenging to acquire and maintain. NEW METHOD Established protocols to harvest primary glia use neonatal rodents, here we provide a method for simultaneously isolating microglia and astrocytes from brain and/or spinal cord from adult rodents. We utilized a discontinuous percoll density gradient enabling easy discrimination of these cell populations without enzymatic digestion or complex sorting techniques. RESULTS We found cells isolated from the percoll interface between 70 %-50 % were microglia, as they express ionizing calcium-binding adaptor molecule 1 (Iba1) in immunocytochemistry and CD11bhi and CD45lo using flow cytometry. Isolated cells from the 50 %-30 % interface were astrocytes as they express glial fibrillary acidic protein (GFAP) in immunocytochemistry and Glutamate aspartate transporter (GLAST)-1 using flow cytometry. Cultured microglia and astrocytes showed a functional increase in IL-6 production after treatment of lipopolysaccharide (LPS). COMPARISON WITH EXISTING METHODS Our method allows for rapid isolation of both microglia and astrocytes in one protocol with relatively few resources, preserves cellular phenotype, and yields high cell numbers without magnetic or antibody sorting. CONCLUSION Here we show a novel, single protocol to isolate microglia and astrocytes from brain and spinal cord tissue, allowing for culturing and other downstream applications from the cells of animals of various ages, which will be useful for researchers investigating these two major glial cell types from the brain or spinal cord of the same rodent.
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249
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Zhou Y, Shao A, Yao Y, Tu S, Deng Y, Zhang J. Dual roles of astrocytes in plasticity and reconstruction after traumatic brain injury. Cell Commun Signal 2020; 18:62. [PMID: 32293472 PMCID: PMC7158016 DOI: 10.1186/s12964-020-00549-2] [Citation(s) in RCA: 100] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 03/06/2020] [Indexed: 12/14/2022] Open
Abstract
Traumatic brain injury (TBI) is one of the leading causes of fatality and disability worldwide. Despite its high prevalence, effective treatment strategies for TBI are limited. Traumatic brain injury induces structural and functional alterations of astrocytes, the most abundant cell type in the brain. As a way of coping with the trauma, astrocytes respond in diverse mechanisms that result in reactive astrogliosis. Astrocytes are involved in the physiopathologic mechanisms of TBI in an extensive and sophisticated manner. Notably, astrocytes have dual roles in TBI, and some astrocyte-derived factors have double and opposite properties. Thus, the suppression or promotion of reactive astrogliosis does not have a substantial curative effect. In contrast, selective stimulation of the beneficial astrocyte-derived molecules and simultaneous attenuation of the deleterious factors based on the spatiotemporal-environment can provide a promising astrocyte-targeting therapeutic strategy. In the current review, we describe for the first time the specific dual roles of astrocytes in neuronal plasticity and reconstruction, including neurogenesis, synaptogenesis, angiogenesis, repair of the blood-brain barrier, and glial scar formation after TBI. We have also classified astrocyte-derived factors depending on their neuroprotective and neurotoxic roles to design more appropriate targeted therapies. Video Abstract
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Affiliation(s)
- Yunxiang Zhou
- Department of Surgical Oncology, The Second Affiliated Hospital, Zhejiang University School of Medicine, No. 88, Jiefang Road, Zhejiang, 310009, Hangzhou, China
| | - Anwen Shao
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Province, Zhejiang, 310009, Hangzhou, China.
| | - Yihan Yao
- Department of Surgical Oncology, The Second Affiliated Hospital, Zhejiang University School of Medicine, No. 88, Jiefang Road, Zhejiang, 310009, Hangzhou, China
| | - Sheng Tu
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, Zhejiang, Hangzhou, China
| | - Yongchuan Deng
- Department of Surgical Oncology, The Second Affiliated Hospital, Zhejiang University School of Medicine, No. 88, Jiefang Road, Zhejiang, 310009, Hangzhou, China
| | - Jianmin Zhang
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Province, Zhejiang, 310009, Hangzhou, China
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250
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Early AN, Gorman AA, Van Eldik LJ, Bachstetter AD, Morganti JM. Effects of advanced age upon astrocyte-specific responses to acute traumatic brain injury in mice. J Neuroinflammation 2020; 17:115. [PMID: 32290848 PMCID: PMC7158022 DOI: 10.1186/s12974-020-01800-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2019] [Accepted: 04/01/2020] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Older-age individuals are at the highest risk for disability from a traumatic brain injury (TBI). Astrocytes are the most numerous glia in the brain, necessary for brain function, yet there is little known about unique responses of astrocytes in the aged-brain following TBI. METHODS Our approach examined astrocytes in young adult, 4-month-old, versus aged, 18-month-old mice, at 1, 3, and 7 days post-TBI. We selected these time points to span the critical period in the transition from acute injury to presumably irreversible tissue damage and disability. Two approaches were used to define the astrocyte contribution to TBI by age interaction: (1) tissue histology and morphological phenotyping, and (2) transcriptomics on enriched astrocytes from the injured brain. RESULTS Aging was found to have a profound effect on the TBI-induced loss of astrocyte function needed for maintaining water transport and edema-namely, aquaporin-4. The aged brain also demonstrated a progressive exacerbation of astrogliosis as a function of time after injury. Moreover, clasmatodendrosis, an underrecognized astrogliopathy, was found to be significantly increased in the aged brain, but not in the young brain. As a function of TBI, we observed a transitory refraction in the number of these astrocytes, which rebounded by 7 days post-injury in the aged brain. Transcriptomic data demonstrated disproportionate changes in genes attributed to reactive astrocytes, inflammatory response, complement pathway, and synaptic support in aged mice following TBI compared to young mice. Additionally, our data highlight that TBI did not evoke a clear alignment with the previously defined "A1/A2" dichotomy of reactive astrogliosis. CONCLUSIONS Overall, our findings point toward a progressive phenotype of aged astrocytes following TBI that we hypothesize to be maladaptive, shedding new insights into potentially modifiable astrocyte-specific mechanisms that may underlie increased fragility of the aged brain to trauma.
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Affiliation(s)
- Alexandria N Early
- Sanders-Brown Center on Aging, University of Kentucky, Room 433, Sanders-Brown Bldg., 800 S. Limestone Street, Lexington, KY, 40536, USA.,Department of Neuroscience, University of Kentucky, Lexington, KY, 40536, USA
| | - Amy A Gorman
- Sanders-Brown Center on Aging, University of Kentucky, Room 433, Sanders-Brown Bldg., 800 S. Limestone Street, Lexington, KY, 40536, USA
| | - Linda J Van Eldik
- Sanders-Brown Center on Aging, University of Kentucky, Room 433, Sanders-Brown Bldg., 800 S. Limestone Street, Lexington, KY, 40536, USA.,Department of Neuroscience, University of Kentucky, Lexington, KY, 40536, USA.,Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, 40536, USA
| | - Adam D Bachstetter
- Sanders-Brown Center on Aging, University of Kentucky, Room 433, Sanders-Brown Bldg., 800 S. Limestone Street, Lexington, KY, 40536, USA.,Department of Neuroscience, University of Kentucky, Lexington, KY, 40536, USA.,Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, 40536, USA
| | - Josh M Morganti
- Sanders-Brown Center on Aging, University of Kentucky, Room 433, Sanders-Brown Bldg., 800 S. Limestone Street, Lexington, KY, 40536, USA. .,Department of Neuroscience, University of Kentucky, Lexington, KY, 40536, USA. .,Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, KY, 40536, USA.
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