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Megagiannis P, Mei Y, Yan RE, Yuan L, Wilde JJ, Eckersberg H, Suresh R, Tan X, Chen H, Farmer WT, Cha K, Le PU, Catoire H, Rochefort D, Kwan T, Yee BA, Dion P, Krishnaswamy A, Cloutier JF, Stifani S, Petrecca K, Yeo GW, Murai KK, Feng G, Rouleau GA, Ideker T, Sanjana NE, Zhou Y. Autism-associated CHD8 controls reactive gliosis and neuroinflammation via remodeling chromatin in astrocytes. Cell Rep 2024; 43:114637. [PMID: 39154337 DOI: 10.1016/j.celrep.2024.114637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Revised: 06/11/2024] [Accepted: 07/30/2024] [Indexed: 08/20/2024] Open
Abstract
Reactive changes of glial cells during neuroinflammation impact brain disorders and disease progression. Elucidating the mechanisms that control reactive gliosis may help us to understand brain pathophysiology and improve outcomes. Here, we report that adult ablation of autism spectrum disorder (ASD)-associated CHD8 in astrocytes attenuates reactive gliosis via remodeling chromatin accessibility, changing gene expression. Conditional Chd8 deletion in astrocytes, but not microglia, suppresses reactive gliosis by impeding astrocyte proliferation and morphological elaboration. Astrocyte Chd8 ablation alleviates lipopolysaccharide-induced neuroinflammation and septic-associated hypothermia in mice. Astrocytic CHD8 plays an important role in neuroinflammation by altering the chromatin landscape, regulating metabolic and lipid-associated pathways, and astrocyte-microglia crosstalk. Moreover, we show that reactive gliosis can be directly mitigated in vivo using an adeno-associated virus (AAV)-mediated Chd8 gene editing strategy. These findings uncover a role of ASD-associated CHD8 in the adult brain, which may warrant future exploration of targeting chromatin remodelers in reactive gliosis and neuroinflammation in injury and neurological diseases.
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Affiliation(s)
- Platon Megagiannis
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Yuan Mei
- Division of Genetics, Department of Medicine, University of California, San Diego, San Diego, CA, USA; Department of Cellular and Molecular Medicine, Stem Cell Program, Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Rachel E Yan
- New York Genome Center, New York, NY, USA; Department of Biology, New York University, New York, NY, USA
| | - Lin Yuan
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Jonathan J Wilde
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Hailey Eckersberg
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Rahul Suresh
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Xinzhu Tan
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Hong Chen
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - W Todd Farmer
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Center, Montreal General Hospital, Montreal, QC, Canada
| | - Kuwook Cha
- Department of Physiology, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Phuong Uyen Le
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Helene Catoire
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Daniel Rochefort
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Tony Kwan
- McGill Genome Center and Department of Human Genetics, McGill University, Montreal, QC, Canada
| | - Brian A Yee
- Department of Cellular and Molecular Medicine, Stem Cell Program, Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Patrick Dion
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Arjun Krishnaswamy
- Department of Physiology, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Jean-Francois Cloutier
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Stefano Stifani
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Kevin Petrecca
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Gene W Yeo
- Department of Cellular and Molecular Medicine, Stem Cell Program, Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA, USA
| | - Keith K Murai
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Center, Montreal General Hospital, Montreal, QC, Canada
| | - Guoping Feng
- Department of Brain and Cognitive Sciences, McGovern Institute for Brain Research, Massachusetts Institute of Technology (MIT), Cambridge, MA, USA; Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Guy A Rouleau
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada
| | - Trey Ideker
- Division of Genetics, Department of Medicine, University of California, San Diego, San Diego, CA, USA.
| | - Neville E Sanjana
- New York Genome Center, New York, NY, USA; Department of Biology, New York University, New York, NY, USA
| | - Yang Zhou
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital, Faculty of Medicine and Health Sciences, McGill University, Montreal, QC, Canada.
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Silva AI, Socodato R, Pinto C, Terceiro AF, Canedo T, Relvas JB, Saraiva M, Summavielle T. IL-10 and Cdc42 modulate astrocyte-mediated microglia activation in methamphetamine-induced neuroinflammation. Glia 2024; 72:1501-1517. [PMID: 38780232 DOI: 10.1002/glia.24542] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 05/03/2024] [Accepted: 05/05/2024] [Indexed: 05/25/2024]
Abstract
Methamphetamine (Meth) use is known to induce complex neuroinflammatory responses, particularly involving astrocytes and microglia. Building upon our previous research, which demonstrated that Meth stimulates astrocytes to release tumor necrosis factor (TNF) and glutamate, leading to microglial activation, this study investigates the role of the anti-inflammatory cytokine interleukin-10 (IL-10) in this process. Our findings reveal that the presence of recombinant IL-10 (rIL-10) counteracts Meth-induced excessive glutamate release in astrocyte cultures, which significantly reduces microglial activation. This reduction is associated with the modulation of astrocytic intracellular calcium (Ca2+) dynamics, particularly by restricting the release of Ca2+ from the endoplasmic reticulum to the cytoplasm. Furthermore, we identify the small Rho GTPase Cdc42 as a crucial intermediary in the astrocyte-to-microglia communication pathway under Meth exposure. By employing a transgenic mouse model that overexpresses IL-10 (pMT-10), we also demonstrate in vivo that IL-10 prevents Meth-induced neuroinflammation. These findings not only enhance our understanding of Meth-related neuroinflammatory mechanisms, but also suggest IL-10 and Cdc42 as putative therapeutic targets for treating Meth-induced neuroinflammation.
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Affiliation(s)
- Ana Isabel Silva
- Addiction Biology Group, i3S-Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Renato Socodato
- Glia Cell Biology Group, i3S-Instituto de Investigação e Inovação em Saúde, Porto, Portugal
| | - Carolina Pinto
- Addiction Biology Group, i3S-Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - Ana Filipa Terceiro
- Addiction Biology Group, i3S-Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - Teresa Canedo
- Addiction Biology Group, i3S-Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
| | - João Bettencourt Relvas
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Glia Cell Biology Group, i3S-Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- Faculty of Medicine of the University of Porto (FMUP), Porto, Portugal
| | - Margarida Saraiva
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- Immune Regulation Group, i3S-Instituto de Investigação e Inovação em Saúde, Porto, Portugal
| | - Teresa Summavielle
- Addiction Biology Group, i3S-Instituto de Investigação e Inovação em Saúde, Porto, Portugal
- IBMC-Instituto de Biologia Molecular e Celular, Universidade do Porto, Porto, Portugal
- ESS.PP, Escola Superior de Saúde do Politécnico do Porto, Porto, Portugal
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3
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Qian Y, Li X, Li G, Liu H, Li Q, Liu X, Zhang Y, He Z, Zhao Y, Fan H. Astrocyte-Derived Exosomal miR-148a-3p Suppresses Neuroinflammation and Restores Neurological Function in Traumatic Brain Injury by Regulating the Microglial Phenotype. eNeuro 2024; 11:ENEURO.0336-23.2024. [PMID: 38272675 PMCID: PMC10860656 DOI: 10.1523/eneuro.0336-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 12/29/2023] [Accepted: 01/01/2024] [Indexed: 01/27/2024] Open
Abstract
Interactions between astrocytes and microglia play an important role in the regeneration and repair of traumatic brain injury (TBI), and exosomes are involved in cell-cell interactions. A TBI model was constructed in rats. Brain extract (Ext) was isolated 1 d after TBI. Astrocyte-derived exosomes were obtained by coculturing Ext with primary astrocytes, and the morphology of exosomes was observed by electron microscopy. The isolated exosomes were cocultured with microglia to observe phenotypic changes in M1 and M2 markers. Aberrant RNA expression was detected in necrotic brain tissue and edematous brain tissue. The role of miR-148a-3p in regulating microglial phenotype was explored by knocking down or overexpressing miR-148a-3p. Finally, the effect of miR-148a-3p on TBI was studied in a rat TBI model. Astrocyte-derived exosomes stimulated by Ext promoted the transition of microglia from the M1 phenotype to the M2 phenotype. MiR-148a-3p was highly expressed in TBI. Transfecting miR-148a-3p promoted the transition of microglia from the M1 phenotype to the M2 phenotype and inhibited the lipopolysaccharide-induced inflammatory response in pre-microglia. In a rat TBI model, miR-148a-3p significantly improved the modified neurological severity score and attenuated brain injury, which promoted the transition of microglia from the M1 phenotype to the M2 phenotype. MiR-148a-3p alleviated TBI by inhibiting the nuclear factor κB pathway. Astrocyte-derived exosomal miR-148a-3p regulates the microglial phenotype, inhibits neuroinflammation, and restores neurological function in TBI. These results provide new potential targets for the treatment of TBI.
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Affiliation(s)
- Yan Qian
- Rehabilitation Medicine, Qujing No.1 Hospital, Qujing, Yunnan 655000, China
| | - Xin Li
- Rehabilitation Medicine, Qujing No.1 Hospital, Qujing, Yunnan 655000, China
| | - Guiliang Li
- Rehabilitation Medicine, Qujing No.1 Hospital, Qujing, Yunnan 655000, China
| | - Huali Liu
- Rehabilitation Medicine, Qujing No.1 Hospital, Qujing, Yunnan 655000, China
| | - Qiaofen Li
- Rehabilitation Medicine, Qujing No.1 Hospital, Qujing, Yunnan 655000, China
| | - Xia Liu
- Rehabilitation Medicine, Qujing No.1 Hospital, Qujing, Yunnan 655000, China
| | - Yang Zhang
- Rehabilitation Medicine, Qujing No.1 Hospital, Qujing, Yunnan 655000, China
| | - Zongying He
- Rehabilitation Medicine, Qujing No.1 Hospital, Qujing, Yunnan 655000, China
| | - Ying Zhao
- Rehabilitation Medicine, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650000, China
| | - Hong Fan
- Rehabilitation Medicine, The Second Affiliated Hospital of Kunming Medical University, Kunming, Yunnan 650000, China
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4
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Cieri MB, Villarreal A, Gomez-Cuautle DD, Mailing I, Ramos AJ. Progression of reactive gliosis and astroglial phenotypic changes following stab wound-induced traumatic brain injury in mice. J Neurochem 2023; 167:183-203. [PMID: 37592830 DOI: 10.1111/jnc.15941] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 06/29/2023] [Accepted: 08/03/2023] [Indexed: 08/19/2023]
Abstract
Astrocytes are the main homeostatic cells in the central nervous system (CNS) and they have an essential role in preserving neuronal physiology. After brain injury, astrocytes become reactive, and that involves a profound change in the astroglial gene expression program as well as intense cytoskeleton remodeling that has been classically shown by the up-regulation of glial fibrillary acidic protein (GFAP), a pan-reactive gene over-expressed in reactive astrocytes, independently of the type of injury. Using the stab wound rodent model of penetrating traumatic injury in the cortex, we here studied the reactive astroglial morphology and reactive microgliosis in detail at 1, 3, 7, 14, and 28 days post-injury (dpi). By combining immunohistochemistry, morphometrical parameters, and Sholl analysis, we segmented the astroglial cell population into clusters of reactive astrocytes that were localized in the core, penumbra, and distal regions of the stab wound. Specifically, highly reactive clusters with more complex morphology, increased C3, decreased aquaporin-4 (AQP4), and glutamine synthetase (GS) expression, were enriched at 7 dpi when behavioral alterations, microgliosis, and neuronal alterations in injured mice were most significant. While pro-inflammatory gain of function with peripheral lipopolysaccharide (LPS) administration immediately after a stab wound expanded these highly reactive astroglial clusters, the treatment with the NF-κB inhibitor sulfasalazine reduced the abundance of this highly reactive cluster. Increased neuronal loss and exacerbated reactive microgliosis at 7 dpi were associated with the expansion of the highly reactive astroglial cluster. We conclude that highly reactive astrocytes found in stab wound injury, but expanded in pro-inflammatory conditions, are a population of astrocytes that become engaged in pathological remodeling with a pro-inflammatory gain of function and loss of homeostatic capacity. Controlling this astroglial population may be a tempting strategy to reduce neuronal loss and neuroinflammation in the injured brain.
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Affiliation(s)
- Maria Belen Cieri
- Laboratorio de Neuropatología Molecular, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis", UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alejandro Villarreal
- Laboratorio de Neuropatología Molecular, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis", UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Dante Daniel Gomez-Cuautle
- Laboratorio de Neuropatología Molecular, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis", UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Ingrid Mailing
- Laboratorio de Neuropatología Molecular, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis", UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Alberto Javier Ramos
- Laboratorio de Neuropatología Molecular, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis", UBA-CONICET, Facultad de Medicina, Universidad de Buenos Aires, Buenos Aires, Argentina
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5
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Muñoz-Ballester C, Robel S. Astrocyte-mediated mechanisms contribute to traumatic brain injury pathology. WIREs Mech Dis 2023; 15:e1622. [PMID: 37332001 PMCID: PMC10526985 DOI: 10.1002/wsbm.1622] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2023] [Revised: 05/25/2023] [Accepted: 05/29/2023] [Indexed: 06/20/2023]
Abstract
Astrocytes respond to traumatic brain injury (TBI) with changes to their molecular make-up and cell biology, which results in changes in astrocyte function. These changes can be adaptive, initiating repair processes in the brain, or detrimental, causing secondary damage including neuronal death or abnormal neuronal activity. The response of astrocytes to TBI is often-but not always-accompanied by the upregulation of intermediate filaments, including glial fibrillary acidic protein (GFAP) and vimentin. Because GFAP is often upregulated in the context of nervous system disturbance, reactive astrogliosis is sometimes treated as an "all-or-none" process. However, the extent of astrocytes' cellular, molecular, and physiological adjustments is not equal for each TBI type or even for each astrocyte within the same injured brain. Additionally, new research highlights that different neurological injuries and diseases result in entirely distinctive and sometimes divergent astrocyte changes. Thus, extrapolating findings on astrocyte biology from one pathological context to another is problematic. We summarize the current knowledge about astrocyte responses specific to TBI and point out open questions that the field should tackle to better understand how astrocytes shape TBI outcomes. We address the astrocyte response to focal versus diffuse TBI and heterogeneity of reactive astrocytes within the same brain, the role of intermediate filament upregulation, functional changes to astrocyte function including potassium and glutamate homeostasis, blood-brain barrier maintenance and repair, metabolism, and reactive oxygen species detoxification, sex differences, and factors influencing astrocyte proliferation after TBI. This article is categorized under: Neurological Diseases > Molecular and Cellular Physiology.
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Affiliation(s)
- Carmen Muñoz-Ballester
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Stefanie Robel
- Department of Cell, Developmental, and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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6
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Liu A, Yu L, Li X, Zhang K, Zhang W, So KF, Tissir F, Qu Y, Zhou L. Celsr2-mediated morphological polarization and functional phenotype of reactive astrocytes in neural repair. Glia 2023. [PMID: 37186402 DOI: 10.1002/glia.24378] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Revised: 04/09/2023] [Accepted: 04/13/2023] [Indexed: 05/17/2023]
Abstract
Neural repair is highly influenced by reactive astrocytes. Atypical cadherin Celsr2 regulates neuron development and axon regeneration, while its role in glial cells remains unexplored. In this study, we show that Celsr2 is highly expressed in spinal astrocytes of adult mice, and knockout of Celsr2 results in reactive astrocytes with longer protrusions preferentially orientated towards lesion borders in culture scratch assay and injured spinal cord, and elevation of total and active Cdc42 and Rac1 protein in western blots. Inactivation of Celsr2 enhances calcium influx in reactive astrocytes in time-lapse imaging. Morphological phenotypes of cultured Celsr2-/- astrocytes are rescued by Cdc42 or Rac1 inhibitors. Following spinal cord injury (SCI), Celsr2-/- mice exhibit smaller lesion cavity and glial scar, enhanced fiber regeneration, weaker microglial response, and improved functional recovery than control animals. Similar phenotypes are found in mice with conditional knockout of Celsr2 in astrocytes. In Celsr2-/- mice, astrocyte phenotype is changed and neuroinflammation is alleviated after injury. Inhibiting Cdc42/Rac1 activities compromises astrocyte polarization and the improvement of neural repair and functional recovery in Celsr2-/- mice with SCI. In conclusion, Celsr2 regulates morphological polarization and functional phenotype of reactive astrocytes and inactivating Celsr2 is a potential therapeutic strategy for neural repair.
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Affiliation(s)
- Aimei Liu
- Guangdong-Hongkong-Macau CNS Regeneration Institute of Jinan University, Key Laboratory of CNS Regeneration (Jinan University)-Ministry of Education, Guangzhou, People's Republic of China
- Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, Shandong, People's Republic of China
| | - Lingtai Yu
- Guangdong-Hongkong-Macau CNS Regeneration Institute of Jinan University, Key Laboratory of CNS Regeneration (Jinan University)-Ministry of Education, Guangzhou, People's Republic of China
| | - Xuejun Li
- Guangdong-Hongkong-Macau CNS Regeneration Institute of Jinan University, Key Laboratory of CNS Regeneration (Jinan University)-Ministry of Education, Guangzhou, People's Republic of China
| | - Kejiao Zhang
- Guangdong-Hongkong-Macau CNS Regeneration Institute of Jinan University, Key Laboratory of CNS Regeneration (Jinan University)-Ministry of Education, Guangzhou, People's Republic of China
| | - Wei Zhang
- Guangdong-Hongkong-Macau CNS Regeneration Institute of Jinan University, Key Laboratory of CNS Regeneration (Jinan University)-Ministry of Education, Guangzhou, People's Republic of China
| | - Kwok-Fai So
- Guangdong-Hongkong-Macau CNS Regeneration Institute of Jinan University, Key Laboratory of CNS Regeneration (Jinan University)-Ministry of Education, Guangzhou, People's Republic of China
- Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, Shandong, People's Republic of China
- Department of Neurology and Stroke Center, The First Affiliated Hospital & Clinical Neuroscience Institute of Jinan University, Guangzhou, People's Republic of China
- Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu, People's Republic of China
- Center for Exercise and Brain Science, School of Psychology, Shanghai University of Sport, Shanghai, People's Republic of China
| | - Fadel Tissir
- Institute of Neuroscience, Developmental Neurobiology, Université catholique de Louvain, Brussels, Belgium
- College of Health and Life Sciences, Hamad Bin Khalifa University (HBKU), Doha, Qatar
| | - Yibo Qu
- Guangdong-Hongkong-Macau CNS Regeneration Institute of Jinan University, Key Laboratory of CNS Regeneration (Jinan University)-Ministry of Education, Guangzhou, People's Republic of China
- Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu, People's Republic of China
- Center for Exercise and Brain Science, School of Psychology, Shanghai University of Sport, Shanghai, People's Republic of China
| | - Libing Zhou
- Guangdong-Hongkong-Macau CNS Regeneration Institute of Jinan University, Key Laboratory of CNS Regeneration (Jinan University)-Ministry of Education, Guangzhou, People's Republic of China
- Neuroscience and Neurorehabilitation Institute, University of Health and Rehabilitation Sciences, Qingdao, Shandong, People's Republic of China
- Department of Neurology and Stroke Center, The First Affiliated Hospital & Clinical Neuroscience Institute of Jinan University, Guangzhou, People's Republic of China
- Co-innovation Center of Neuroregeneration, Nantong University, Jiangsu, People's Republic of China
- Center for Exercise and Brain Science, School of Psychology, Shanghai University of Sport, Shanghai, People's Republic of China
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7
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Zhang Q, Shi R, Hao M, Feng D, Wu R, Shi M. NDRG2 regulates the formation of reactive astrocyte-derived progenitor cells via Notch signaling pathway after brain traumatic injury in rats. Front Mol Neurosci 2023; 16:1149683. [PMID: 37082656 PMCID: PMC10112515 DOI: 10.3389/fnmol.2023.1149683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2023] [Accepted: 03/21/2023] [Indexed: 04/07/2023] Open
Abstract
In response to traumatic brain injury, a subpopulation of cortical astrocytes is activated, resulting in acquisition of stem cell properties, known as reactive astrocytes-derived progenitor cells (Rad-PCs). However, the underlying mechanisms remain largely unknown during this process. In this study, we examined the role of N-myc downstream-regulated gene 2 (NDRG2), a differentiation- and stress-associated molecule, in Rad-PCs after cortical stab injury in adult rats. Immunohistochemical analysis showed that in the cerebral cortex of normal adult rats, NDRG2 was exclusively expressed in astrocytes. After liu cortical injury, the expression of NDRG2 was significantly elevated around the wound and most cells expressing NDRG2 also expressed GFAP, a reactive astrocyte marker. Importantly, NDRG2-expressing cells were co-labeled with Nestin, a marker for neural stem cells, some of which also expressed cell proliferation marker Ki67. Overexpression of NDRG2 further increased the number of NDRG2/Nestin double-labeling cells around the lesion. In contrast, shRNA knockdown of NDRG2 decreased the number of NDRG2+/Nestin+ cells. Intracerebroventricular administration of stab-injured rats with a Notch antagonist, DAPT, led to a significant decrease in Nestin+/NDRG2+ cells around the injured boundary, but did not affect NDRG2+ cells. Moreover, overexpression or knockdown of NDRG2 led to up- and down-regulation of the expression of Notch intracellular domain NICD and Notch target gene Hes1, respectively. Taken together, these results suggest that NDRG2 may play a role in controlling the formation of Rad-PCs in the cerebral cortex of adult rats following traumatic injury, and that Notch signaling pathway plays a key role in this process.
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Affiliation(s)
- Qinjun Zhang
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, China
- Department of Neurology, Meishan Cardio-Cerebrovascular Disease Hospital, Meishan, Sichuan, China
| | - Rui Shi
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, China
| | - Minghua Hao
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, China
- Department of Neurology, Shandong Armed Police General Hospital, Jinan, Shandong, China
| | - Dongyun Feng
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, China
| | - Rui Wu
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, China
| | - Ming Shi
- Department of Neurology, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi, China
- *Correspondence: Ming Shi,
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8
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Luo J. Dysregulation of polarity proteins in astrocyte reactivity. Ageing Res Rev 2023; 86:101869. [PMID: 36736704 PMCID: PMC10026364 DOI: 10.1016/j.arr.2023.101869] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 01/13/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023]
Abstract
Astrocytes are highly polarized neuroglial cells. Polarity is the basis for many of the diverse roles that astrocytes play in the normal and injured brain. Astrocytes are generally dormant and non-migratory under normal physiological conditions, where they perform a wide variety of intricate and essential tasks in preserving CNS homeostasis. In response to pathological insults, astrocytes shift from the normal dormant and homeostatic state to a reactive and migratory state through a process referred to as "reactive astrogliosis". Cell polarity proteins play a key role in the initiation and regulation of migration. Recent evidence suggests that cell polarity proteins are dysregulated during astrogliosis and may modulate astrocyte reactivity and alter the course of disease. Therefore, cell polarity proteins may provide novel therapeutic targets for modulating astrocyte reactivity in brain disorders.
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Affiliation(s)
- Jian Luo
- Palo Alto Veterans Institute for Research, VAPAHCS, Palo Alto, CA 94304, USA.
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9
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Hu X, Li S, Shi Z, Lin WJ, Yang Y, Li Y, Li H, Xu Y, Zhou M, Tang Y. Partial Ablation of Astrocytes Exacerbates Cerebral Infiltration of Monocytes and Neuronal Loss After Brain Stab Injury in Mice. Cell Mol Neurobiol 2023; 43:893-905. [PMID: 35437650 DOI: 10.1007/s10571-022-01224-5] [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: 12/15/2021] [Accepted: 03/31/2022] [Indexed: 11/03/2022]
Abstract
In traumatic brain injury (TBI), mechanical injury results in instantaneous tissue damages accompanied by subsequent pro-inflammatory cascades composed of microgliosis and astrogliosis. However, the interactive roles between microglia and astrocytes during the pathogenesis of TBI remain unclear and sometimes debatable. In this study, we used a forebrain stab injury mouse model to investigate the pathological role of reactive astrocytes in cellular and molecular changes of inflammatory response following TBI. In the ipsilateral hemisphere of stab-injured brain, monocyte infiltration and neuronal loss, as well as increased elevated astrogliosis, microglia activation and inflammatory cytokines were observed. To verify the role of reactive astrocytes in TBI, local and partial ablation of astrocytes was achieved by stereotactic injection of diphtheria toxin in the forebrain of Aldh1l1-CreERT2::Ai9::iDTR transgenic mice which expressed diphtheria toxin receptor (DTR) in astrocytes after tamoxifen induction. This strategy achieved about 20% of astrocytes reduction at the stab site as validated by immunofluorescence co-staining of GFAP with tdTomato-positive astrocytes. Interestingly, reduction of astrocytes showed increased microglia activation and monocyte infiltration, accompanied with increased severity in stab injury-induced neuronal loss when compared with DTR-/- mice, together with elevation of inflammatory chemokines such as CCL2, CCL5 and CXCL10 in astrogliosis-reduced mice. Collectively, our data verified the interactive role of astrocytes as an immune modulator in suppressing inflammatory responses in the injured brain. Schematic diagram shows monocyte infiltration and neuronal loss, as well as increased elevated astrogliosis, microglia activation and chemokines were observed in the injured site after stab injury. Local and partial ablation of astrocytes led to increased microglia activation and monocyte infiltration, accompanied with increased severity in neuronal loss together with elevation of inflammatory chemokines as compared with control mice subjected stab injury.
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Affiliation(s)
- Xia Hu
- Department of Radiation Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, China
| | - Shaojian Li
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat‑Sen University, Guangzhou, 510120, China
| | - Zhongshan Shi
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat‑Sen University, Guangzhou, 510120, China
| | - Wei-Jye Lin
- Brain Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China.,Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China.,Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, 510275, China
| | - Yuhua Yang
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat‑Sen University, Guangzhou, 510120, China
| | - Yi Li
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat‑Sen University, Guangzhou, 510120, China
| | - Honghong Li
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat‑Sen University, Guangzhou, 510120, China
| | - Yongteng Xu
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat‑Sen University, Guangzhou, 510120, China
| | - Meijuan Zhou
- Department of Radiation Medicine, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, 510515, China.
| | - Yamei Tang
- Department of Neurology, Sun Yat-Sen Memorial Hospital, Sun Yat‑Sen University, Guangzhou, 510120, China. .,Brain Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China. .,Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China. .,Key Laboratory of Malignant Tumor Gene Regulation and Target Therapy of Guangdong Higher Education Institutes, Sun Yat-Sen University, Guangzhou, 510275, China.
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10
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Domingos C, Müller FE, Passlick S, Wachten D, Ponimaskin E, Schwarz MK, Schoch S, Zeug A, Henneberger C. Induced Remodelling of Astrocytes In Vitro and In Vivo by Manipulation of Astrocytic RhoA Activity. Cells 2023; 12:331. [PMID: 36672265 PMCID: PMC9856770 DOI: 10.3390/cells12020331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/05/2023] [Accepted: 01/11/2023] [Indexed: 01/17/2023] Open
Abstract
Structural changes of astrocytes and their perisynaptic processes occur in response to various physiological and pathophysiological stimuli. They are thought to profoundly affect synaptic signalling and neuron-astrocyte communication. Understanding the causal relationship between astrocyte morphology changes and their functional consequences requires experimental tools to selectively manipulate astrocyte morphology. Previous studies indicate that RhoA-related signalling can play a major role in controlling astrocyte morphology, but the direct effect of increased RhoA activity has not been documented in vitro and in vivo. Therefore, we established a viral approach to manipulate astrocytic RhoA activity. We tested if and how overexpression of wild-type RhoA, of a constitutively active RhoA mutant (RhoA-CA), and of a dominant-negative RhoA variant changes the morphology of cultured astrocytes. We found that astrocytic expression of RhoA-CA induced robust cytoskeletal changes and a withdrawal of processes in cultured astrocytes. In contrast, overexpression of other RhoA variants led to more variable changes of astrocyte morphology. These induced morphology changes were reproduced in astrocytes of the hippocampus in vivo. Importantly, astrocytic overexpression of RhoA-CA did not alter the branching pattern of larger GFAP-positive processes of astrocytes. This indicates that a prolonged increase of astrocytic RhoA activity leads to a distinct morphological phenotype in vitro and in vivo, which is characterized by an isolated reduction of fine peripheral astrocyte processes in vivo. At the same time, we identified a promising experimental approach for investigating the functional consequences of astrocyte morphology changes.
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Affiliation(s)
- Cátia Domingos
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | | | - Stefan Passlick
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - Dagmar Wachten
- Institute of Innate Immunity, Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - Evgeni Ponimaskin
- Cellular Neurophysiology, Hannover Medical School, 30625 Hannover, Germany
| | - Martin K. Schwarz
- Institute of Experimental Epileptology and Cognition Research (EECR), Medical Faculty, University of Bonn, 53127 Bonn, Germany
| | - Susanne Schoch
- Institute of Neuropathology, University of Bonn Medical School, 53127 Bonn, Germany
| | - André Zeug
- Cellular Neurophysiology, Hannover Medical School, 30625 Hannover, Germany
| | - Christian Henneberger
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, 53127 Bonn, Germany
- German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany
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11
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Munoz-Ballester C, Mahmutovic D, Rafiqzad Y, Korot A, Robel S. Mild Traumatic Brain Injury-Induced Disruption of the Blood-Brain Barrier Triggers an Atypical Neuronal Response. Front Cell Neurosci 2022; 16:821885. [PMID: 35250487 PMCID: PMC8894613 DOI: 10.3389/fncel.2022.821885] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/17/2022] [Indexed: 12/03/2022] Open
Abstract
Mild TBI (mTBI), which affects 75% of TBI survivors or more than 50 million people worldwide each year, can lead to consequences including sleep disturbances, cognitive impairment, mood swings, and post-traumatic epilepsy in a subset of patients. To interrupt the progression of these comorbidities, identifying early pathological events is key. Recent studies have shown that microbleeds, caused by mechanical impact, persist for months after mTBI and are correlated to worse mTBI outcomes. However, the impact of mTBI-induced blood-brain barrier damage on neurons is yet to be revealed. We used a well-characterized mouse model of mTBI that presents with frequent and widespread but size-restricted damage to the blood-brain barrier to assess how neurons respond to exposure of blood-borne factors in this pathological context. We used immunohistochemistry and histology to assess the expression of neuronal proteins in excitatory and inhibitory neurons after mTBI. We observed that the expression of NeuN, Parvalbumin, and CamKII was lost within minutes in areas with blood-brain barrier disruption. Yet, the neurons remained alive and could be detected using a fluorescent Nissl staining even 6 months later. A similar phenotype was observed after exposure of neurons to blood-borne factors due to endothelial cell ablation in the absence of a mechanical impact, suggesting that entrance of blood-borne factors into the brain is sufficient to induce the neuronal atypical response. Changes in postsynaptic spines were observed indicative of functional changes. Thus, this study demonstrates That exposure of neurons to blood-borne factors causes a rapid and sustained loss of neuronal proteins and changes in spine morphology in the absence of neurodegeneration, a finding that is likely relevant to many neuropathologies.
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Affiliation(s)
- Carmen Munoz-Ballester
- Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, VA, United States
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Dzenis Mahmutovic
- Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, VA, United States
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Yusuf Rafiqzad
- Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, VA, United States
- School of Neuroscience, Virginia Tech Carilion, Blacksburg, VA, United States
| | - Alia Korot
- Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, VA, United States
- Kenyon College, Gambier, OH, United States
| | - Stefanie Robel
- Fralin Biomedical Research Institute, Virginia Tech Carilion, Roanoke, VA, United States
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL, United States
- School of Neuroscience, Virginia Tech Carilion, Blacksburg, VA, United States
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12
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Wegrzyn D, Zokol J, Faissner A. Vav3-Deficient Astrocytes Enhance the Dendritic Development of Hippocampal Neurons in an Indirect Co-culture System. Front Cell Neurosci 2022; 15:817277. [PMID: 35237130 PMCID: PMC8882586 DOI: 10.3389/fncel.2021.817277] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Accepted: 12/29/2021] [Indexed: 12/19/2022] Open
Abstract
Vav proteins belong to the class of guanine nucleotide exchange factors (GEFs) that catalyze the exchange of guanosine diphosphate (GDP) by guanosine triphosphate (GTP) on their target proteins. Here, especially the members of the small GTPase family, Ras homolog family member A (RhoA), Ras-related C3 botulinum toxin substrate 1 (Rac1) and cell division control protein 42 homolog (Cdc42) can be brought into an activated state by the catalytic activity of Vav-GEFs. In the central nervous system (CNS) of rodents Vav3 shows the strongest expression pattern in comparison to Vav2 and Vav1, which is restricted to the hematopoietic system. Several studies revealed an important role of Vav3 for the elongation and branching of neurites. However, little is known about the function of Vav3 for other cell types of the CNS, like astrocytes. Therefore, the following study analyzed the effects of a Vav3 knockout on several astrocytic parameters as well as the influence of Vav3-deficient astrocytes on the dendritic development of cultured neurons. For this purpose, an indirect co-culture system of native hippocampal neurons and Vav3-deficient cortical astrocytes was used. Interestingly, neurons cultured in an indirect contact with Vav3-deficient astrocytes showed a significant increase in the dendritic complexity and length after 12 and 17 days in vitro (DIV). Furthermore, Vav3-deficient astrocytes showed an enhanced regeneration in the scratch wound heal assay as well as an altered profile of released cytokines with a complete lack of CXCL11, reduced levels of IL-6 and an increased release of CCL5. Based on these observations, we suppose that Vav3 plays an important role for the development of dendrites by regulating the expression and the release of neurotrophic factors and cytokines in astrocytes.
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13
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Vitorino LC, Oliveira KF, da Silva WAB, de Andrade Gomes CAB, Romão LF, Allodi S, Correa CL. Physical exercise influences astrocytes in the striatum of a Parkinson's disease male mouse model. Neurosci Lett 2022; 771:136466. [PMID: 35051434 DOI: 10.1016/j.neulet.2022.136466] [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: 09/21/2021] [Revised: 01/12/2022] [Accepted: 01/14/2022] [Indexed: 11/24/2022]
Abstract
Physical exercise is considered an adjuvant treatment to Parkinson's disease (PD) patients, possibly reducing inflammatory responses in the brain. Studies have stated that physical exercise protects dopaminergic neurons in PD models produced by neurotoxins. However, few studies focused on immunohistochemically reacted astrocytes and morphometric analyses of these cells in a PD mouse model submitted to physical exercise. We investigated the effects of treadmill training on striatal astrocytes of a PD mouse model combining immunohistochemistry and western-blotting for glial fibrillary acidic protein (GFAP) with morphometric analyses. Male Swiss mice were divided into 4 groups: sedentary control (SEDCONT), exercise control (EXERCONT), sedentary Parkinson (SEDPD), and exercise Parkinson (EXERPD). Stereotaxic bilateral injections of 6-hydroxydopamine into the striatum were adopted for PD groups. Striatal astrocytes showed increased GFAP in EXERPD, and we observed a higher level of GFAP in EXERPD than SEDPD. The number of primary and secondary processes was similar in striatal astrocytes of control groups and EXERPD. The astrocyte primary processes of SEDPD were larger than those of EXERPD, EXERCONT and SEDCONT. Cell body diameters and areas showed no difference between groups. We concluded that physical exercise influences striatal astrocytes in exercised parkinsonian mice.
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Affiliation(s)
- Louise Caroline Vitorino
- Programa de Pós-Graduação em Ciências Morfológicas, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Laboratório de Neurobiologia Comparativa e do Desenvolvimento, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro. Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil.
| | - Karla Ferreira Oliveira
- Programa de Pós-Graduação em Ciências Biológicas - Fisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Laboratório de Neurobiologia Comparativa e do Desenvolvimento, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro. Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil.
| | - Wagner Antonio Barbosa da Silva
- Programa de Pós-Graduação em Ciências Biológicas - Fisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Laboratório de Neurobiologia Comparativa e do Desenvolvimento, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro. Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil.
| | - Carlos Augusto Borges de Andrade Gomes
- Laboratório de Neurobiologia Comparativa e do Desenvolvimento, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro. Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Programa de Pós-Graduação em Ciências Biológicas - Biofísica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil.
| | - Luciana Ferreira Romão
- Programa de Pós-Graduação em Ciências Morfológicas, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil.
| | - Silvana Allodi
- Programa de Pós-Graduação em Ciências Morfológicas, Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Programa de Pós-Graduação em Ciências Biológicas - Fisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Laboratório de Neurobiologia Comparativa e do Desenvolvimento, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro. Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Programa de Pós-Graduação em Ciências Biológicas - Biofísica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil.
| | - Clynton Lourenço Correa
- Programa de Pós-Graduação em Ciências Biológicas - Fisiologia, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Laboratório de Neurobiologia Comparativa e do Desenvolvimento, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro. Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Programa de Pós-Graduação em Ciências Biológicas - Biofísica, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373, Ilha do Fundão, 21941-902 Rio de Janeiro, RJ, Brazil; Faculdade de Fisioterapia, Universidade Federal do Rio de Janeiro. R. Rodolpho Paulo Rocco 255 - HUCFF, Ilha do Fundão 21941-590 Rio de Janeiro, RJ, Brazil.
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In vitro model of traumatic brain injury to screen neuro-regenerative biomaterials. MATERIALS SCIENCE & ENGINEERING. C, MATERIALS FOR BIOLOGICAL APPLICATIONS 2021; 128:112253. [PMID: 34474815 DOI: 10.1016/j.msec.2021.112253] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Revised: 05/21/2021] [Accepted: 06/11/2021] [Indexed: 11/24/2022]
Abstract
Penetrating traumatic brain injury (pTBI) causes serious neurological deficits with no clinical regenerative therapies currently available. Tissue engineering strategies using biomaterial-based 'structural bridges' offer high potential to promote neural regeneration post-injury. This includes surgical grade materials which can be repurposed as biological scaffolds to overcome challenges associated with long approval processes and scaleup for human application. However, high throughput, pathomimetic models of pTBI are lacking for the developmental testing of such neuro-materials, representing a bottleneck in this rapidly emergent field. We have established a high throughput and facile culture model containing the major neural cell types which govern biomaterial handling in the central nervous system. We show that induction of traumatic injuries was feasible in the model, with post-injury implantation of a surgical grade biomaterial. Cellular imaging in lesions was achievable using standard epifluorescence microscopy methods. Key pathological features of pTBI were evident in vitro namely immune cell infiltration of lesions/biomaterial, with responses characteristic of cell scarring, namely hypertrophic astrocytes with GFAP upregulation. Based on our observations, we consider the high-throughput, inexpensive and facile pTBI model can be used to study biomaterial 'implantation' and evaluate neural cell-biomaterial responses. The model is highly versatile to test a range of laboratory and clinical grade materials for neural regeneration.
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15
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Neuron and astrocyte aggregation and sorting in three-dimensional neuronal constructs. Commun Biol 2021; 4:587. [PMID: 34002005 PMCID: PMC8129100 DOI: 10.1038/s42003-021-02104-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 04/09/2021] [Indexed: 02/03/2023] Open
Abstract
Aggregation and self-sorting of cells in three dimensional cultures have been described for non-neuronal cells. Despite increased interest in engineered neural tissues for treating brain injury or for modeling neurological disorders in vitro, little data is available on collective cell movements in neuronal aggregates. Migration and sorting of cells may alter these constructs' morphology and, therefore, the function of their neural circuitry. In this work, linear, adhered rat and human 3D neuronal-astrocyte cultures were developed to enable the study of aggregation and sorting of these cells. An in silico model of the contraction, clustering, and cell sorting in the 3D cultures was also developed. Experiments and computational modeling showed that aggregation was mainly a neuron mediated process, and formation of astrocyte-rich sheaths in 3D cultures depended on differential attraction between neurons and astrocytes. In silico model predicted formation of self-assembled neuronal layers in disk-shaped 3D cultures. Neuronal activity patterns were found to correlate with local morphological differences. This model of neuronal and astrocyte aggregation and sorting may benefit future design of neuronal constructs.
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16
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Schiweck J, Murk K, Ledderose J, Münster-Wandowski A, Ornaghi M, Vida I, Eickholt BJ. Drebrin controls scar formation and astrocyte reactivity upon traumatic brain injury by regulating membrane trafficking. Nat Commun 2021; 12:1490. [PMID: 33674568 PMCID: PMC7935889 DOI: 10.1038/s41467-021-21662-x] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Accepted: 01/27/2021] [Indexed: 01/31/2023] Open
Abstract
The brain of mammals lacks a significant ability to regenerate neurons and is thus particularly vulnerable. To protect the brain from injury and disease, damage control by astrocytes through astrogliosis and scar formation is vital. Here, we show that brain injury in mice triggers an immediate upregulation of the actin-binding protein Drebrin (DBN) in astrocytes, which is essential for scar formation and maintenance of astrocyte reactivity. In turn, DBN loss leads to defective astrocyte scar formation and excessive neurodegeneration following brain injuries. At the cellular level, we show that DBN switches actin homeostasis from ARP2/3-dependent arrays to microtubule-compatible scaffolds, facilitating the formation of RAB8-positive membrane tubules. This injury-specific RAB8 membrane compartment serves as hub for the trafficking of surface proteins involved in astrogliosis and adhesion mediators, such as β1-integrin. Our work shows that DBN-mediated membrane trafficking in astrocytes is an important neuroprotective mechanism following traumatic brain injury in mice.
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Affiliation(s)
- Juliane Schiweck
- grid.6363.00000 0001 2218 4662Institute of Biochemistry, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Kai Murk
- grid.6363.00000 0001 2218 4662Institute of Biochemistry, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Julia Ledderose
- grid.6363.00000 0001 2218 4662Institute of Biochemistry, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | | | - Marta Ornaghi
- grid.6363.00000 0001 2218 4662Institute of Biochemistry, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Imre Vida
- grid.6363.00000 0001 2218 4662Institute of Anatomy, Charité - Universitätsmedizin Berlin, Berlin, Germany
| | - Britta J. Eickholt
- grid.6363.00000 0001 2218 4662Institute of Biochemistry, Charité - Universitätsmedizin Berlin, Berlin, Germany ,grid.6363.00000 0001 2218 4662NeuroCure - Cluster of Excellence, Charité - Universitätsmedizin Berlin, Berlin, Germany
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17
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Chen M, Guo L, Hao J, Ni J, Lv Q, Xin X, Liao H. p75NTR Promotes Astrocyte Proliferation in Response to Cortical Stab Wound. Cell Mol Neurobiol 2020; 42:1153-1166. [DOI: 10.1007/s10571-020-01006-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Accepted: 11/11/2020] [Indexed: 01/15/2023]
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18
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Ariyani W, Miyazaki W, Amano I, Hanamura K, Shirao T, Koibuchi N. Soy Isoflavones Accelerate Glial Cell Migration via GPER-Mediated Signal Transduction Pathway. Front Endocrinol (Lausanne) 2020; 11:554941. [PMID: 33250856 PMCID: PMC7672195 DOI: 10.3389/fendo.2020.554941] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Accepted: 10/12/2020] [Indexed: 01/04/2023] Open
Abstract
Soybean isoflavones, such as genistein, daidzein, and its metabolite, S-equol, are widely known as phytoestrogens. Their biological actions are thought to be exerted via the estrogen signal transduction pathway. Estrogens, such as 17β-estradiol (E2), play a crucial role in the development and functional maintenance of the central nervous system. E2 bind to the nuclear estrogen receptor (ER) and regulates morphogenesis, migration, functional maturation, and intracellular metabolism of neurons and glial cells. In addition to binding to nuclear ER, E2 also binds to the G-protein-coupled estrogen receptor (GPER) and activates the nongenomic estrogen signaling pathway. Soybean isoflavones also bind to the ER and GPER. However, the effect of soybean isoflavone on brain development, particularly glial cell function, remains unclear. We examined the effects of soybean isoflavones using an astrocyte-enriched culture and astrocyte-derived C6 clonal cells. Isoflavones increased glial cell migration. This augmentation was suppressed by co-exposure with G15, a selective GPER antagonist, or knockdown of GPER expression using RNA interference. Isoflavones also activated actin cytoskeleton arrangement via increased actin polymerization and cortical actin, resulting in an increased number and length of filopodia. Isoflavones exposure increased the phosphorylation levels of FAK (Tyr397 and Tyr576/577), ERK1/2 (Thr202/Tyr204), Akt (Ser473), and Rac1/cdc42 (Ser71), and the expression levels of cortactin, paxillin and ERα. These effects were suppressed by knockdown of the GPER. Co-exposure of isoflavones to the selective RhoA inhibitor, rhosin, selective Cdc42 inhibitor, casin, or Rac1/Cdc42 inhibitor, ML-141, decreased the effects of isoflavones on cell migration. These findings indicate that soybean isoflavones exert their action via the GPER to activate the PI3K/FAK/Akt/RhoA/Rac1/Cdc42 signaling pathway, resulting in increased glial cell migration. Furthermore, in silico molecular docking studies to examine the binding mode of isoflavones to the GPER revealed the possibility that isoflavones bind directly to the GPER at the same position as E2, further confirming that the effects of the isoflavones are at least in part exerted via the GPER signal transduction pathway. The findings of the present study indicate that isoflavones may be an effective supplement to promote astrocyte migration in developing and/or injured adult brains.
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Affiliation(s)
- Winda Ariyani
- Research Fellow of Japan Society for the Promotion of Science, Tokyo, Japan
- Department of Integrative Physiology, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Wataru Miyazaki
- Department of Integrative Physiology, Graduate School of Medicine, Gunma University, Maebashi, Japan
- Department of Bioscience and Laboratory Medicine, Graduate School of Health Science, Hirosaki University, Hirosaki, Japan
| | - Izuki Amano
- Department of Integrative Physiology, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Kenji Hanamura
- Department of Neurobiology and Behavior, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Tomoaki Shirao
- Department of Neurobiology and Behavior, Graduate School of Medicine, Gunma University, Maebashi, Japan
| | - Noriyuki Koibuchi
- Department of Integrative Physiology, Graduate School of Medicine, Gunma University, Maebashi, Japan
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19
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Heithoff BP, George KK, Phares AN, Zuidhoek IA, Munoz-Ballester C, Robel S. Astrocytes are necessary for blood-brain barrier maintenance in the adult mouse brain. Glia 2020; 69:436-472. [PMID: 32955153 DOI: 10.1002/glia.23908] [Citation(s) in RCA: 130] [Impact Index Per Article: 32.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2020] [Revised: 07/22/2020] [Accepted: 08/26/2020] [Indexed: 12/19/2022]
Abstract
In the adult brain, multiple cell types are known to produce factors that regulate blood-brain barrier (BBB) properties, including astrocytes. Yet several recent studies disputed a role for mature astrocytes at the BBB. To determine if astrocytes contribute a nonredundant and necessary function in maintaining the adult BBB, we used a mouse model of tamoxifen-inducible astrocyte ablation. In adult mice, tamoxifen induction caused sparse apoptotic astrocyte cell death within 2 hr. Indicative of BBB damage, leakage of the small molecule Cadaverine, and the large plasma protein fibrinogen into the brain parenchyma indicative of BBB damage was detected as early as astrocyte ablation was present. Vessels within and close to regions of astrocyte loss had lower expression of the tight junction protein zonula occludens-1 while endothelial glucose transporter 1 expression was undisturbed. Cadaverine leakage persisted for several weeks suggesting a lack of barrier repair. This is consistent with the finding that ablated astrocytes were not replaced. Adjacent astrocytes responded with partial nonproliferative astrogliosis, characterized by morphological changes and delayed phosphorylation of STAT3, which restricted dye leakage to the brain and vessel surface areas lacking coverage by astrocytes 1 month after ablation. In conclusion, astrocytes are necessary to maintain BBB integrity in the adult brain. BBB-regulating factors secreted by other cell types, such as pericytes, are not sufficient to compensate for astrocyte loss.
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Affiliation(s)
- Benjamin P Heithoff
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, USA.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA
| | - Kijana K George
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, USA.,Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Roanoke, Virginia, USA
| | - Aubrey N Phares
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, USA.,School of Neuroscience, Virginia Tech, Blacksburg, Virginia, USA
| | - Ivan A Zuidhoek
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, USA.,Graduate Program in Translational Biology, Medicine, and Health, Virginia Tech, Roanoke, Virginia, USA
| | | | - Stefanie Robel
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, Virginia, USA.,Department of Biological Sciences, Virginia Tech, Blacksburg, Virginia, USA.,School of Neuroscience, Virginia Tech, Blacksburg, Virginia, USA
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20
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Damisah EC, Hill RA, Rai A, Chen F, Rothlin CV, Ghosh S, Grutzendler J. Astrocytes and microglia play orchestrated roles and respect phagocytic territories during neuronal corpse removal in vivo. SCIENCE ADVANCES 2020; 6:eaba3239. [PMID: 32637606 PMCID: PMC7319765 DOI: 10.1126/sciadv.aba3239] [Citation(s) in RCA: 157] [Impact Index Per Article: 39.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2019] [Accepted: 05/12/2020] [Indexed: 05/09/2023]
Abstract
Cell death is prevalent throughout life; however, the coordinated interactions and roles of phagocytes during corpse removal in the live brain are poorly understood. We developed photochemical and viral methodologies to induce death in single cells and combined this with intravital optical imaging. This approach allowed us to track multicellular phagocytic interactions with precise spatiotemporal resolution. Astrocytes and microglia engaged with dying neurons in an orchestrated and synchronized fashion. Each glial cell played specialized roles: Astrocyte processes rapidly polarized and engulfed numerous small dendritic apoptotic bodies, while microglia migrated and engulfed the soma and apical dendrites. The relative involvement and phagocytic specialization of each glial cell was plastic and controlled by the receptor tyrosine kinase Mertk. In aging, there was a marked delay in apoptotic cell removal. Thus, a precisely orchestrated response and cross-talk between glial cells during corpse removal may be critical for maintaining brain homeostasis.
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Affiliation(s)
- Eyiyemisi C. Damisah
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Department of Neurosurgery, Yale School of Medicine, New Haven, CT, USA
| | - Robert A. Hill
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Department of Biological Sciences, Dartmouth College, Hanover, NH, USA
| | - Anupama Rai
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | - Fuyi Chen
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | - Carla V. Rothlin
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, USA
- Department of Pharmacology, Yale School of Medicine, New Haven, CT, USA
| | - Sourav Ghosh
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Department of Pharmacology, Yale School of Medicine, New Haven, CT, USA
| | - Jaime Grutzendler
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
- Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
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21
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Jossin Y. Molecular mechanisms of cell polarity in a range of model systems and in migrating neurons. Mol Cell Neurosci 2020; 106:103503. [PMID: 32485296 DOI: 10.1016/j.mcn.2020.103503] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 04/20/2020] [Accepted: 05/23/2020] [Indexed: 01/09/2023] Open
Abstract
Cell polarity is defined as the asymmetric distribution of cellular components along an axis. Most cells, from the simplest single-cell organisms to highly specialized mammalian cells, are polarized and use similar mechanisms to generate and maintain polarity. Cell polarity is important for cells to migrate, form tissues, and coordinate activities. During development of the mammalian cerebral cortex, cell polarity is essential for neurogenesis and for the migration of newborn but as-yet undifferentiated neurons. These oriented migrations include both the radial migration of excitatory projection neurons and the tangential migration of inhibitory interneurons. In this review, I will first describe the development of the cerebral cortex, as revealed at the cellular level. I will then define the core molecular mechanisms - the Par/Crb/Scrib polarity complexes, small GTPases, the actin and microtubule cytoskeletons, and phosphoinositides/PI3K signaling - that are required for asymmetric cell division, apico-basal and front-rear polarity in model systems, including C elegans zygote, Drosophila embryos and cultured mammalian cells. As I go through each core mechanism I will explain what is known about its importance in radial and tangential migration in the developing mammalian cerebral cortex.
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Affiliation(s)
- Yves Jossin
- Laboratory of Mammalian Development & Cell Biology, Institute of Neuroscience, Université Catholique de Louvain, Brussels, Belgium.
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22
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Namekata K, Guo X, Kimura A, Azuchi Y, Kitamura Y, Harada C, Harada T. Roles of the DOCK-D family proteins in a mouse model of neuroinflammation. J Biol Chem 2020; 295:6710-6720. [PMID: 32241915 DOI: 10.1074/jbc.ra119.010438] [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: 08/01/2019] [Revised: 03/16/2020] [Indexed: 02/01/2023] Open
Abstract
The DOCK-D (dedicator of cytokinesis D) family proteins are atypical guanine nucleotide exchange factors that regulate Rho GTPase activity. The family consists of Zizimin1 (DOCK9), Zizimin2 (DOCK11), and Zizimin3 (DOCK10). Functions of the DOCK-D family proteins are presently not well-explored, and the role of the DOCK-D family in neuroinflammation is unknown. In this study, we generated three mouse lines in which DOCK9 (DOCK9 -/-), DOCK10 (DOCK10 -/-), or DOCK11 (DOCK11 -/-) had been deleted and examined the phenotypic effects of these gene deletions in MOG35-55 peptide-induced experimental autoimmune encephalomyelitis, an animal model of the neuroinflammatory disorder multiple sclerosis. We found that all the gene knockout lines were healthy and viable. The only phenotype observed under normal conditions was a slightly smaller proportion of B cells in splenocytes in DOCK10 -/- mice than in the other mouse lines. We also found that the migration ability of macrophages is impaired in DOCK10 -/- and DOCK11 -/- mice and that the severity of experimental autoimmune encephalomyelitis was ameliorated only in DOCK10 -/- mice. No apparent phenotype was observed for DOCK9 -/- mice. Further investigations indicated that lipopolysaccharide stimulation up-regulates DOCK10 expression in microglia and that microglial migration is decreased in DOCK10 -/- mice. Up-regulation of C-C motif chemokine ligand 2 (CCL2) expression induced by activation of Toll-like receptor 4 or 9 signaling was reduced in DOCK10 -/- astrocytes compared with WT astrocytes. Taken together, our findings suggest that DOCK10 plays a role in innate immunity and neuroinflammation and might represent a potential therapeutic target for managing multiple sclerosis.
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Affiliation(s)
- Kazuhiko Namekata
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Xiaoli Guo
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Atsuko Kimura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Yuriko Azuchi
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Yuta Kitamura
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Chikako Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
| | - Takayuki Harada
- Visual Research Project, Tokyo Metropolitan Institute of Medical Science, Tokyo 156-8506, Japan
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23
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Lee EJ, Han JC, Park DY, Kee C. A neuroglia-based interpretation of glaucomatous neuroretinal rim thinning in the optic nerve head. Prog Retin Eye Res 2020; 77:100840. [PMID: 31982595 DOI: 10.1016/j.preteyeres.2020.100840] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 01/02/2020] [Accepted: 01/13/2020] [Indexed: 12/14/2022]
Abstract
Neuroretinal rim thinning (NRR) is a characteristic glaucomatous optic disc change. However, the precise mechanism of the rim thinning has not been completely elucidated. This review focuses on the structural role of the glioarchitecture in the formation of the glaucomatous NRR thinning. The NRR is a glia-framed structure, with honeycomb geometry and mechanically reinforced astrocyte processes along the transverse plane. When neural damage selectively involves the neuron and spares the glia, the gross structure of the tissue is preserved. The disorganization and loss of the glioarchitecture are the two hallmarks of optic nerve head (ONH) remodeling in glaucoma that leads to the thinning of NRR tissue upon axonal loss. This is in contrast to most non-glaucomatous optic neuropathies with optic disc pallor where hypertrophy of the glioarchitecture is associated with the seemingly absent optic disc cupping. Arteritic anterior ischemic optic neuropathy is an exception where pan-necrosis of ONH tissue leads to NRR thinning. Milder ischemia indicates selective neuronal loss that spares glia in non-arteritic anterior ischemic optic neuropathy. The biological reason is the heterogeneous glial response determined by the site, type, and severity of the injury. The neuroglial interpretation explains how the cellular changes underlie the clinical findings. Updated understandings on glial responses illustrate the mechanical, microenvironmental, and microglial modulation of activated astrocytes in glaucoma. Findings relevant to the possible mechanism of the astrocyte death in advanced glaucoma are also emerging. Ultimately, a better understanding of glaucomatous glial response may lead to glia-targeting neuroprotection in the future.
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Affiliation(s)
- Eun Jung Lee
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul, 06351, South Korea
| | - Jong Chul Han
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul, 06351, South Korea
| | - Do Young Park
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul, 06351, South Korea
| | - Changwon Kee
- Department of Ophthalmology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-Ro, Gangnam-gu, Seoul, 06351, South Korea.
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24
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Potassium and glutamate transport is impaired in scar-forming tumor-associated astrocytes. Neurochem Int 2019; 133:104628. [PMID: 31825815 PMCID: PMC6957761 DOI: 10.1016/j.neuint.2019.104628] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 12/04/2019] [Accepted: 12/05/2019] [Indexed: 01/09/2023]
Abstract
Unprovoked recurrent seizures are a serious comorbidity affecting most patients who suffer from glioma, a primary brain tumor composed of malignant glial cells. Cellular mechanisms contributing to the development of recurrent spontaneous seizures include the release of the excitatory neurotransmitter glutamate from glioma into extracellular space. Under physiological conditions, astrocytes express two high affinity glutamate transporters, Glt-1 and Glast, which are responsible for the removal of excess extracellular glutamate. In the context of neurological disease or brain injury, astrocytes become reactive which can negatively affect neuronal function, causing hyperexcitability and/or death. Using electrophysiology, immunohistochemistry, fluorescent in situ hybridization, and Western blot analysis in different orthotopic xenograft and allograft models of human and mouse gliomas, we find that peritumoral astrocytes exhibit astrocyte scar formation characterized by proliferation, cellular hypertrophy, process elongation, and increased GFAP and pSTAT3. Overall, peritumoral reactive astrocytes show a significant reduction in glutamate and potassium uptake, as well as decreased glutamine synthetase activity. A subset of peritumoral astrocytes displayed a depolarized resting membrane potential, further contributing to reduced potassium and glutamate homeostasis. These changes may contribute to the propagation of peritumoral neuronal hyperexcitability and excitotoxic death.
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25
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Mattugini N, Bocchi R, Scheuss V, Russo GL, Torper O, Lao CL, Götz M. Inducing Different Neuronal Subtypes from Astrocytes in the Injured Mouse Cerebral Cortex. Neuron 2019; 103:1086-1095.e5. [PMID: 31488328 PMCID: PMC6859713 DOI: 10.1016/j.neuron.2019.08.009] [Citation(s) in RCA: 93] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 05/24/2019] [Accepted: 08/03/2019] [Indexed: 01/14/2023]
Abstract
Astrocytes are particularly promising candidates for reprogramming into neurons, as they maintain some of the original patterning information from their radial glial ancestors. However, to which extent the position of astrocytes influences the fate of reprogrammed neurons remains unknown. To elucidate this, we performed stab wound injury covering an entire neocortical column, including the gray matter (GM) and white matter (WM), and targeted local reactive astrocytes via injecting FLEx switch (Cre-On) adeno-associated viral (AAV) vectors into mGFAP-Cre mice. Single proneural factors were not sufficient for adequate reprogramming, although their combination with the nuclear receptor-related 1 protein (Nurr1) improved reprogramming efficiency. Nurr1 and Neurogenin 2 (Ngn2) resulted in high-efficiency reprogramming of targeted astrocytes into neurons that develop lamina-specific hallmarks, including the appropriate long-distance axonal projections. Surprisingly, in the WM, we did not observe any reprogrammed neurons, thereby unveiling a crucial role of region- and layer-specific differences in astrocyte reprogramming.
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Affiliation(s)
- Nicola Mattugini
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians-Universitaet (LMU), Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany; Helmholtz Center Munich, Biomedical Center (BMC), Institute of Stem Cell Research, Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany; Graduate School of Systemic Neuroscience, Ludwig-Maximilians-Universitaet (LMU), Großhaderner Str. 2, 82152 Planegg/Martinsried, Germany
| | - Riccardo Bocchi
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians-Universitaet (LMU), Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany; Helmholtz Center Munich, Biomedical Center (BMC), Institute of Stem Cell Research, Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany
| | - Volker Scheuss
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians-Universitaet (LMU), Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany; Helmholtz Center Munich, Biomedical Center (BMC), Institute of Stem Cell Research, Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany
| | - Gianluca Luigi Russo
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians-Universitaet (LMU), Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany; Helmholtz Center Munich, Biomedical Center (BMC), Institute of Stem Cell Research, Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany; Graduate School of Systemic Neuroscience, Ludwig-Maximilians-Universitaet (LMU), Großhaderner Str. 2, 82152 Planegg/Martinsried, Germany
| | - Olof Torper
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians-Universitaet (LMU), Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany; Helmholtz Center Munich, Biomedical Center (BMC), Institute of Stem Cell Research, Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany
| | - Chu Lan Lao
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians-Universitaet (LMU), Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany; Helmholtz Center Munich, Biomedical Center (BMC), Institute of Stem Cell Research, Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany
| | - Magdalena Götz
- Physiological Genomics, Biomedical Center (BMC), Ludwig-Maximilians-Universitaet (LMU), Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany; Helmholtz Center Munich, Biomedical Center (BMC), Institute of Stem Cell Research, Großhaderner Str. 9, 82152 Planegg/Martinsried, Germany; SyNergy Excellence Cluster, Munich, Germany.
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26
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Escartin C, Guillemaud O, Carrillo-de Sauvage MA. Questions and (some) answers on reactive astrocytes. Glia 2019; 67:2221-2247. [PMID: 31429127 DOI: 10.1002/glia.23687] [Citation(s) in RCA: 173] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Revised: 06/12/2019] [Accepted: 06/28/2019] [Indexed: 02/06/2023]
Abstract
Astrocytes are key cellular partners for neurons in the central nervous system. Astrocytes react to virtually all types of pathological alterations in brain homeostasis by significant morphological and molecular changes. This response was classically viewed as stereotypical and is called astrogliosis or astrocyte reactivity. It was long considered as a nonspecific, secondary reaction to pathological conditions, offering no clues on disease-causing mechanisms and with little therapeutic value. However, many studies over the last 30 years have underlined the crucial and active roles played by astrocytes in physiology, ranging from metabolic support, synapse maturation, and pruning to fine regulation of synaptic transmission. This prompted researchers to explore how these new astrocyte functions were changed in disease, and they reported alterations in many of them (sometimes beneficial, mostly deleterious). More recently, cell-specific transcriptomics revealed that astrocytes undergo massive changes in gene expression when they become reactive. This observation further stressed that reactive astrocytes may be very different from normal, nonreactive astrocytes and could influence disease outcomes. To make the picture even more complex, both normal and reactive astrocytes were shown to be molecularly and functionally heterogeneous. Very little is known about the specific roles that each subtype of reactive astrocytes may play in different disease contexts. In this review, we have interrogated researchers in the field to identify and discuss points of consensus and controversies about reactive astrocytes, starting with their very name. We then present the emerging knowledge on these cells and future challenges in this field.
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Affiliation(s)
- Carole Escartin
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département de la Recherche Fondamentale, Institut de Biologie François Jacob, MIRCen, Fontenay-aux-Roses, France.,Centre National de la Recherche Scientifique, Univ. Paris Sud, Univ. Paris-Saclay, UMR 9199, Neurodegenerative Disease Laboratory, Fontenay-aux-Roses, France
| | - Océane Guillemaud
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département de la Recherche Fondamentale, Institut de Biologie François Jacob, MIRCen, Fontenay-aux-Roses, France.,Centre National de la Recherche Scientifique, Univ. Paris Sud, Univ. Paris-Saclay, UMR 9199, Neurodegenerative Disease Laboratory, Fontenay-aux-Roses, France
| | - Maria-Angeles Carrillo-de Sauvage
- Commissariat à l'Energie Atomique et aux Energies Alternatives, Département de la Recherche Fondamentale, Institut de Biologie François Jacob, MIRCen, Fontenay-aux-Roses, France.,Centre National de la Recherche Scientifique, Univ. Paris Sud, Univ. Paris-Saclay, UMR 9199, Neurodegenerative Disease Laboratory, Fontenay-aux-Roses, France
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27
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Chen Y, Sha R, Xu L, Xia Y, Liu Y, Li X, Xie HQ, Tang N, Zhao B. 2,3,7,8-Tetrachlorodibenzo-p-dioxin promotes migration ability of primary cultured rat astrocytes via aryl hydrocarbon receptor. J Environ Sci (China) 2019; 76:368-376. [PMID: 30528028 DOI: 10.1016/j.jes.2018.05.030] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/25/2018] [Accepted: 05/28/2018] [Indexed: 06/09/2023]
Abstract
Emerging evidence showed that 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) could induce expression of certain reactivation-associated genes in astrocytes, however, the consequent cellular effects and molecular mechanisms are still unclear. During the process of astrocyte reactivation, migration is a critical cellular event. In the present study, we employed wound-healing assay and Transwell® motility assay to explore the effects of TCDD on cell migration in primary cultured rat cortical astrocytes. We found that upon TCDD treatments at relative low concentrations (10-10 and/or 10-9 mol/L), the ability of primary astrocytes to migrate horizontally and vertically was promoted. In line with this cellular effect, the mRNA expression of two pro-migratory genes, including cell division cycle 42 (CDC42) and matrix metalloproteinase 2 (MMP2) was induced by TCDD treatment. Dioxin exerts its toxic effects mainly through aryl hydrocarbon receptor (AhR) pathway. So the role of AhR pathway in the pro-migratory effects of TCDD was examined using an AhR antagonist, CH223191. We found that application of CH223191 significantly reversed the pro-migratory effects of TCDD. Interestingly, the basal ability of horizontal migration as well as basal levels of CDC42 and MMP2 expression were dramatically reduced suggesting a possible physiological role of AhR in maintaining the endogenous migration ability of the primary astrocytes. These findings support the notion that dioxin promotes astrocyte reactivation at molecular and cellular levels.
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Affiliation(s)
- Yangsheng Chen
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100085, China.
| | - Rui Sha
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100085, China
| | - Li Xu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100085, China
| | - Yingjie Xia
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100085, China
| | - Yiyun Liu
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100085, China
| | - Xuejun Li
- Department of Occupational and Environmental Health, s, Tianjin Medical University, Tianjin 300070, China
| | - Heidi Qunhui Xie
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100085, China.
| | - Naijun Tang
- Department of Occupational and Environmental Health, s, Tianjin Medical University, Tianjin 300070, China
| | - Bin Zhao
- State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100085, China.
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28
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Repetitive Diffuse Mild Traumatic Brain Injury Causes an Atypical Astrocyte Response and Spontaneous Recurrent Seizures. J Neurosci 2019; 39:1944-1963. [PMID: 30665946 DOI: 10.1523/jneurosci.1067-18.2018] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Revised: 12/18/2018] [Accepted: 12/20/2018] [Indexed: 11/21/2022] Open
Abstract
Focal traumatic brain injury (TBI) induces astrogliosis, a process essential to protecting uninjured brain areas from secondary damage. However, astrogliosis can cause loss of astrocyte homeostatic functions and possibly contributes to comorbidities such as posttraumatic epilepsy (PTE). Scar-forming astrocytes seal focal injuries off from healthy brain tissue. It is these glial scars that are associated with epilepsy originating in the cerebral cortex and hippocampus. However, the vast majority of human TBIs also present with diffuse brain injury caused by acceleration-deceleration forces leading to tissue shearing. The resulting diffuse tissue damage may be intrinsically different from focal lesions that would trigger glial scar formation. Here, we used mice of both sexes in a model of repetitive mild/concussive closed-head TBI, which only induced diffuse injury, to test the hypothesis that astrocytes respond uniquely to diffuse TBI and that diffuse TBI is sufficient to cause PTE. Astrocytes did not form scars and classic astrogliosis characterized by upregulation of glial fibrillary acidic protein was limited. Surprisingly, an unrelated population of atypical reactive astrocytes was characterized by the lack of glial fibrillary acidic protein expression, rapid and sustained downregulation of homeostatic proteins and impaired astrocyte coupling. After a latency period, a subset of mice developed spontaneous recurrent seizures reminiscent of PTE in human TBI patients. Seizing mice had larger areas of atypical astrocytes compared with nonseizing mice, suggesting that these atypical astrocytes might contribute to epileptogenesis after diffuse TBI.SIGNIFICANCE STATEMENT Traumatic brain injury (TBI) is a leading cause of acquired epilepsies. Reactive astrocytes have long been associated with seizures and epilepsy in patients, particularly after focal/lesional brain injury. However, most TBIs also include nonfocal, diffuse injuries. Here, we showed that repetitive diffuse TBI is sufficient for the development of spontaneous recurrent seizures in a subset of mice. We identified an atypical response of astrocytes induced by diffuse TBI characterized by the rapid loss of homeostatic proteins and lack of astrocyte coupling while reactive astrocyte markers or glial scar formation was absent. Areas with atypical astrocytes were larger in animals that later developed seizures suggesting that this response may be one root cause of epileptogenesis after diffuse TBI.
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29
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Park H, You N, Lee J, Suh M. Longitudinal study of hemodynamics and dendritic membrane potential changes in the mouse cortex following a soft cranial window installation. NEUROPHOTONICS 2019; 6:015006. [PMID: 30820438 PMCID: PMC6387987 DOI: 10.1117/1.nph.6.1.015006] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 01/25/2019] [Indexed: 05/21/2023]
Abstract
The soft cranial window using polydimethylsiloxane allows direct multiple access to neural tissue during long-term monitoring. However, the chronic effects of soft window installation on the brain have not been fully studied. Here, we investigate the long-term effects of soft window installation on sensory-evoked cerebral hemodynamics and neuronal activity. We monitored the brain tissue immunocytohistology for 6 weeks postinstallation. Heightened reactive astrocytic and microglia levels were found at 2 weeks postinstallation. By 6 weeks postinstallation, mice had expression levels similar to those of normal animals. We recorded sensory-evoked hemodynamics of the barrel cortex and LFP during whisker stimulation at these time points. Animals at 6 weeks postinstallation showed stronger hemodynamic responses and focalized barrel mapping than 2-week postoperative mice. LFP recordings of 6-week postoperative mice also showed higher neural activity at the barrel column corresponding to the stimulated whisker. Furthermore, the expression level of interleukin- 1 β was highly upregulated at 2 weeks postinstallation. When we treated animals postoperatively with minocycline plus N-acetylcystein, a drug-suppressing inflammatory cytokine, these animals did not show declined hemodynamic responses and neuronal activities. This result suggests that neuroinflammation following soft window installation may alter hemodynamic and neuronal responses upon sensory stimulation.
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Affiliation(s)
- Hyejin Park
- Institute for Basic Science, Center for Neuroscience Imaging Research, Suwon, Republic of Korea
- Sungkyunkwan University, Department of Biological Sciences, Suwon, Republic of Korea
- Sungkyunkwan University, Biomedical Institute for Convergence, Suwon, Republic of Korea
| | - Nayeon You
- Institute for Basic Science, Center for Neuroscience Imaging Research, Suwon, Republic of Korea
- Sungkyunkwan University, Department of Biomedical Engineering, Suwon, Republic of Korea
| | - Juheon Lee
- Institute for Basic Science, Center for Neuroscience Imaging Research, Suwon, Republic of Korea
- Sungkyunkwan University, Department of Biomedical Engineering, Suwon, Republic of Korea
| | - Minah Suh
- Institute for Basic Science, Center for Neuroscience Imaging Research, Suwon, Republic of Korea
- Sungkyunkwan University, Biomedical Institute for Convergence, Suwon, Republic of Korea
- Sungkyunkwan University, Department of Biomedical Engineering, Suwon, Republic of Korea
- Sungkyunkwan University, SAHIST, Suwon, Republic of Korea
- Address all correspondence to Minah Suh, E-mail:
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30
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Schiweck J, Eickholt BJ, Murk K. Important Shapeshifter: Mechanisms Allowing Astrocytes to Respond to the Changing Nervous System During Development, Injury and Disease. Front Cell Neurosci 2018; 12:261. [PMID: 30186118 PMCID: PMC6111612 DOI: 10.3389/fncel.2018.00261] [Citation(s) in RCA: 136] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2018] [Accepted: 07/31/2018] [Indexed: 12/30/2022] Open
Abstract
Astrocytes are the most prevalent glial cells in the brain. Historically considered as “merely supporting” neurons, recent research has shown that astrocytes actively participate in a large variety of central nervous system (CNS) functions including synaptogenesis, neuronal transmission and synaptic plasticity. During disease and injury, astrocytes efficiently protect neurons by various means, notably by sealing them off from neurotoxic factors and repairing the blood-brain barrier. Their ramified morphology allows them to perform diverse tasks by interacting with synapses, blood vessels and other glial cells. In this review article, we provide an overview of how astrocytes acquire their complex morphology during development. We then move from the developing to the mature brain, and review current research on perisynaptic astrocytic processes, with a particular focus on how astrocytes engage synapses and modulate their formation and activity. Comprehensive changes have been reported in astrocyte cell shape in many CNS pathologies. Factors influencing these morphological changes are summarized in the context of brain pathologies, such as traumatic injury and degenerative conditions. We provide insight into the molecular, cellular and cytoskeletal machinery behind these shape changes which drive the dynamic remodeling in astrocyte morphology during injury and the development of pathologies.
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Affiliation(s)
- Juliane Schiweck
- Institute for Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Britta J Eickholt
- Institute for Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Kai Murk
- Institute for Biochemistry, Charité Universitätsmedizin Berlin, Berlin, Germany
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31
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Frik J, Merl-Pham J, Plesnila N, Mattugini N, Kjell J, Kraska J, Gómez RM, Hauck SM, Sirko S, Götz M. Cross-talk between monocyte invasion and astrocyte proliferation regulates scarring in brain injury. EMBO Rep 2018; 19:embr.201745294. [PMID: 29632244 PMCID: PMC5934774 DOI: 10.15252/embr.201745294] [Citation(s) in RCA: 79] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Revised: 03/02/2018] [Accepted: 03/09/2018] [Indexed: 01/02/2023] Open
Abstract
Scar formation after brain injury is still poorly understood. To further elucidate such processes, here, we examine the interplay between astrocyte proliferation taking place predominantly at the vascular interface and monocyte invasion. Using genetic mouse models that decrease or increase reactive astrocyte proliferation, we demonstrate inverse effects on monocyte numbers in the injury site. Conversely, reducing monocyte invasion using CCR2-/- mice causes a strong increase in astrocyte proliferation, demonstrating an intriguing negative cross-regulation between these cell types at the vascular interface. CCR2-/- mice show reduced scar formation with less extracellular matrix deposition, smaller lesion site and increased neuronal coverage. Surprisingly, the GFAP+ scar area in these mice is also significantly decreased despite increased astrocyte proliferation. Proteomic analysis at the peak of increased astrocyte proliferation reveals a decrease in extracellular matrix synthesizing enzymes in the injury sites of CCR2-/- mice, highlighting how early key aspects of scar formation are initiated. Taken together, we provide novel insights into the cross-regulation of juxtavascular proliferating astrocytes and invading monocytes as a crucial mechanism of scar formation upon brain injury.
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Affiliation(s)
- Jesica Frik
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany.,Institute for Stem Cell Research, Helmholtz Center Munich, Munich, Germany.,Instituto de Biotecnología y Biología Molecular, UNLP-CONICET, La Plata, Argentina
| | - Juliane Merl-Pham
- Research Unit for Protein Science, Helmholtz Center Munich, Munich, Germany
| | - Nikolaus Plesnila
- Institute for Stroke and Dementia Research, Experimental Stroke Research, University of Munich Medical School, Munich, Germany.,SYNERGY, Excellence Cluster Systems Neurology, University of Munich, Munich, Germany
| | - Nicola Mattugini
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany.,Institute for Stem Cell Research, Helmholtz Center Munich, Munich, Germany.,Graduate School of Systemic Neurosciences, Biocenter, Ludwig-Maximilians-University of Munich, Munich, Germany
| | - Jacob Kjell
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany.,Institute for Stem Cell Research, Helmholtz Center Munich, Munich, Germany
| | - Jonas Kraska
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Ricardo M Gómez
- Instituto de Biotecnología y Biología Molecular, UNLP-CONICET, La Plata, Argentina
| | - Stefanie M Hauck
- Research Unit for Protein Science, Helmholtz Center Munich, Munich, Germany
| | - Swetlana Sirko
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany .,Institute for Stem Cell Research, Helmholtz Center Munich, Munich, Germany
| | - Magdalena Götz
- Physiological Genomics, Biomedical Center, Ludwig-Maximilians-University Munich, Munich, Germany .,Institute for Stem Cell Research, Helmholtz Center Munich, Munich, Germany.,SYNERGY, Excellence Cluster Systems Neurology, University of Munich, Munich, Germany
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32
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Radial Glial Fibers Promote Neuronal Migration and Functional Recovery after Neonatal Brain Injury. Cell Stem Cell 2018; 22:128-137.e9. [DOI: 10.1016/j.stem.2017.11.005] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Revised: 09/14/2017] [Accepted: 11/06/2017] [Indexed: 11/20/2022]
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33
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Mann ZF, Gálvez H, Pedreno D, Chen Z, Chrysostomou E, Żak M, Kang M, Canden E, Daudet N. Shaping of inner ear sensory organs through antagonistic interactions between Notch signalling and Lmx1a. eLife 2017; 6:e33323. [PMID: 29199954 PMCID: PMC5724992 DOI: 10.7554/elife.33323] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Accepted: 12/02/2017] [Indexed: 12/19/2022] Open
Abstract
The mechanisms of formation of the distinct sensory organs of the inner ear and the non-sensory domains that separate them are still unclear. Here, we show that several sensory patches arise by progressive segregation from a common prosensory domain in the embryonic chicken and mouse otocyst. This process is regulated by mutually antagonistic signals: Notch signalling and Lmx1a. Notch-mediated lateral induction promotes prosensory fate. Some of the early Notch-active cells, however, are normally diverted from this fate and increasing lateral induction produces misshapen or fused sensory organs in the chick. Conversely Lmx1a (or cLmx1b in the chick) allows sensory organ segregation by antagonizing lateral induction and promoting commitment to the non-sensory fate. Our findings highlight the dynamic nature of sensory patch formation and the labile character of the sensory-competent progenitors, which could have facilitated the emergence of new inner ear organs and their functional diversification in the course of evolution.
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Affiliation(s)
- Zoe F Mann
- The Ear InstituteUniversity College LondonLondonUnited Kingdom
| | - Héctor Gálvez
- The Ear InstituteUniversity College LondonLondonUnited Kingdom
| | - David Pedreno
- The Ear InstituteUniversity College LondonLondonUnited Kingdom
| | - Ziqi Chen
- The Ear InstituteUniversity College LondonLondonUnited Kingdom
| | | | - Magdalena Żak
- The Ear InstituteUniversity College LondonLondonUnited Kingdom
| | - Miso Kang
- The Ear InstituteUniversity College LondonLondonUnited Kingdom
| | | | - Nicolas Daudet
- The Ear InstituteUniversity College LondonLondonUnited Kingdom
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34
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Grandvuillemin I, Garrigue P, Ramdani A, Boubred F, Simeoni U, Dignat-George F, Sabatier F, Guillet B. Long-Term Recovery After Endothelial Colony-Forming Cells or Human Umbilical Cord Blood Cells Administration in a Rat Model of Neonatal Hypoxic-Ischemic Encephalopathy. Stem Cells Transl Med 2017; 6:1987-1996. [PMID: 28980775 PMCID: PMC6430056 DOI: 10.1002/sctm.17-0074] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Accepted: 07/26/2017] [Indexed: 02/06/2023] Open
Abstract
Neonatal hypoxic‐ischemic encephalopathy (NHIE) is a dramatic perinatal complication, associated with poor neurological prognosis despite neuroprotection by therapeutic hypothermia, in the absence of an available curative therapy. We evaluated and compared ready‐to‐use human umbilical cord blood cells (HUCBC) and bankable but allogeneic endothelial progenitors (ECFC) as cell therapy candidate for NHIE. We compared benefits of HUCBC and ECFC transplantation 48 hours after injury in male rat NHIE model, based on the Rice‐Vannucci approach. Based on behavioral tests, immune‐histological assessment and metabolic imaging of brain perfusion using single photon emission computed tomography (SPECT), HUCBC, or ECFC administration provided equally early and sustained functional benefits, up to 8 weeks after injury. These results were associated with total normalization of injured hemisphere cerebral blood flow assessed by SPECT/CT imaging. In conclusion, even if ECFC represent an efficient candidate, HUCBC autologous criteria and easier availability make them the ideal candidate for hypoxic‐ischemic cell therapy. Stem Cells Translational Medicine2017;6:1987–1996
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Affiliation(s)
- Isabelle Grandvuillemin
- Aix Marseille Univ, INSERM, VRCM, UMR_1076, UFR de Pharmacie, Marseille, France.,APHM, CHU La Conception, Department of Neonatology, Marseille, France
| | - Philippe Garrigue
- Aix Marseille Univ, INSERM, VRCM, UMR_1076, UFR de Pharmacie, Marseille, France.,APHM, Radiopharmacy, Marseille, France.,CERIMED, Aix Marseille Univ, Marseille, France
| | - Alaa Ramdani
- Aix Marseille Univ, INSERM, VRCM, UMR_1076, UFR de Pharmacie, Marseille, France
| | - Farid Boubred
- Aix Marseille Univ, INSERM, VRCM, UMR_1076, UFR de Pharmacie, Marseille, France.,APHM, CHU La Conception, Department of Neonatology, Marseille, France
| | - Umberto Simeoni
- Division of Pediatrics, CHUV & University of Lausanne, Switzerland
| | | | - Florence Sabatier
- Aix Marseille Univ, INSERM, VRCM, UMR_1076, UFR de Pharmacie, Marseille, France.,APHM, CHU La Conception, Cell Culture and Therapy Laboratory, INSERM CBT-1409, Marseille, France
| | - Benjamin Guillet
- Aix Marseille Univ, INSERM, VRCM, UMR_1076, UFR de Pharmacie, Marseille, France.,APHM, Radiopharmacy, Marseille, France.,CERIMED, Aix Marseille Univ, Marseille, France
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35
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Baez-Jurado E, Hidalgo-Lanussa O, Guio-Vega G, Ashraf GM, Echeverria V, Aliev G, Barreto GE. Conditioned Medium of Human Adipose Mesenchymal Stem Cells Increases Wound Closure and Protects Human Astrocytes Following Scratch Assay In Vitro. Mol Neurobiol 2017; 55:5377-5392. [PMID: 28936798 DOI: 10.1007/s12035-017-0771-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2017] [Accepted: 09/11/2017] [Indexed: 12/16/2022]
Abstract
Astrocytes perform essential functions in the preservation of neural tissue. For this reason, these cells can respond with changes in gene expression, hypertrophy, and proliferation upon a traumatic brain injury event (TBI). Different therapeutic strategies may be focused on preserving astrocyte functions and favor a non-generalized and non-sustained protective response over time post-injury. A recent strategy has been the use of the conditioned medium of human adipose mesenchymal stem cells (CM-hMSCA) as a therapeutic strategy for the treatment of various neuropathologies. However, although there is a lot of information about its effect on neuronal protection, studies on astrocytes are scarce and its specific action in glial cells is not well explored. In the present study, the effects of CM-hMSCA on human astrocytes subjected to scratch assay were assessed. Our findings indicated that CM-hMSCA improved cell viability, reduced nuclear fragmentation, and preserved mitochondrial membrane potential. These effects were accompanied by morphological changes and an increased polarity index thus reflecting the ability of astrocytes to migrate to the wound stimulated by CM-hMSCA. In conclusion, CM-hMSCA may be considered as a promising therapeutic strategy for the protection of astrocyte function in brain pathologies.
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Affiliation(s)
- Eliana Baez-Jurado
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, D.C., Colombia
| | - Oscar Hidalgo-Lanussa
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, D.C., Colombia
| | - Gina Guio-Vega
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, D.C., Colombia
| | - Ghulam Md Ashraf
- King Fahd Medical Research Center, King Abdulaziz University, Jeddah, Saudi Arabia
| | - Valentina Echeverria
- Research & Development Service, Bay Pines VA Healthcare System, Bay Pines, FL, 33744, USA.,Fac. Cs de la Salud, Universidad San Sebastián, Lientur 1457, 4080871, Concepción, Chile
| | - Gjumrakch Aliev
- Institute of Physiologically Active Compounds, Russian Academy of Sciences, Chernogolovka, Moscow Region, 142432, Russia.,GALLY International Biomedical Research Consulting LLC, San Antonio, TX, 78229, USA.,School of Health Science and Healthcare Administration, University of Atlanta, Johns Creek, GA, 30097, USA
| | - George E Barreto
- Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá, D.C., Colombia. .,Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile.
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36
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Teo JD, Morris MJ, Jones NM. Maternal obesity increases inflammation and exacerbates damage following neonatal hypoxic-ischaemic brain injury in rats. Brain Behav Immun 2017; 63:186-196. [PMID: 27746186 DOI: 10.1016/j.bbi.2016.10.010] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 10/11/2016] [Accepted: 10/12/2016] [Indexed: 11/18/2022] Open
Abstract
OBJECTIVE In humans, maternal obesity is associated with an increase in the incidence of birth related difficulties. However, the impact of maternal obesity on the severity of brain injury in offspring is not known. Recent studies have found evidence of increased glial response and inflammatory mediators in the brains as a result of obesity in humans and rodents. We hypothesised that hypoxic-ischaemic (HI) brain injury is greater in neonatal offspring from obese rat mothers compared to lean controls. METHODS Female Sprague Dawley rats were randomly allocated to high fat (HFD, n=8) or chow (n=4) diet and mated with lean male rats. On postnatal day 7 (P7), male and female pups were randomly assigned to HI injury or control (C) groups. HI injury was induced by occlusion of the right carotid artery followed by 3h exposure to 8% oxygen, at 37°C. Control pups were removed from the mother for the same duration under ambient conditions. Righting behaviour was measured on day 1 and 7 following HI. The extent of brain injury was quantified in brain sections from P14 pups using cresyl violet staining and the difference in volume between brain hemispheres was measured. RESULTS Before mating, HFD mothers were 11% heavier than Chow mothers (p<0.05, t-test). Righting reflex was delayed in offspring from HFD-fed mothers compared to the Chow mothers. The Chow-HI pups showed a loss in ipsilateral brain tissue, while the HFD-HI group had significantly greater loss. No significant difference was detected in brain volume between the HFD-C and Chow-C pups. When analysed on a per litter basis, the size of the injury was significantly correlated with maternal weight. Similar observations were made with neuronal staining showing a greater loss of neurons in the brain of offspring from HFD-mothers following HI compared to Chow. Astrocytes appeared to more hypertrophic and a greater number of microglia were present in the injured hemisphere in offspring from mothers on HFD. HI caused an increase in the proportion of amoeboid microglia and exposure to maternal HFD exacerbated this response. In the contralateral hemisphere, offspring exposed to maternal HFD displayed a reduced proportion of ramified microglia. CONCLUSIONS Our data clearly demonstrate that maternal obesity can exacerbate the severity of brain damage caused by HI in neonatal offspring. Given that previous studies have shown enhanced inflammatory responses in offspring of obese mothers, these factors including gliosis and microglial infiltration are likely to contribute to enhanced brain injury.
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Affiliation(s)
- Jonathan D Teo
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, New South Wales, Australia
| | - Margaret J Morris
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, New South Wales, Australia
| | - Nicole M Jones
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, New South Wales, Australia.
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37
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Control of astrocyte morphology by Rho GTPases. Brain Res Bull 2017; 136:44-53. [PMID: 28502648 DOI: 10.1016/j.brainresbull.2017.05.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Revised: 05/05/2017] [Accepted: 05/10/2017] [Indexed: 12/15/2022]
Abstract
Astrocytes modulate and support neuronal and synapse function via numerous mechanisms that often rely on diffusion of signalling molecules, ions or metabolites through extracellular space. As a consequence, the spatial arrangement and the distance between astrocyte processes and neuronal structures are of functional importance. Likewise, changes of astrocyte structure will affect the ability of astrocytes to interact with neurons. In contrast to neurons, where rapid morphology changes are critically involved in many aspects of physiological brain function, a role of astrocyte restructuring in brain physiology is only beginning to emerge. In neurons, small GTPases of the Rho family are powerful initiators and modulators of structural changes. Less is known about the functional significance of these signalling molecules in astrocytes. Here, we review recent experimental evidence for the role of RhoA, Cdc42 and Rac1 in controlling dynamic astrocyte morphology as well as experimental tools and analytical approaches for studying astrocyte morphology changes.
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38
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Abstract
Epilepsy is among the most prevalent chronic neurological diseases and affects an estimated 2.2 million people in the United States alone. About one third of patients are resistant to currently available antiepileptic drugs, which are exclusively targeting neuronal function. Yet, reactive astrocytes have emerged as potential contributors to neuronal hyperexcitability and seizures. Astrocytes react to any kind of CNS insult with a range of cellular adjustments to form a scar and protect uninjured brain regions. This process changes astrocyte physiology and can affect neuronal network function in various ways. Traumatic brain injury and stroke, both conditions that trigger astroglial scar formation, are leading causes of acquired epilepsies and surgical removal of this glial scar in patients with drug-resistant epilepsy can alleviate the seizures. This review will summarize the currently available evidence suggesting that epilepsy is not a disease of neurons alone, but that astrocytes, glial cells in the brain, can be major contributors to the disease, especially when they adopt a reactive state in response to central nervous system insult.
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Affiliation(s)
- Stefanie Robel
- Virginia Tech Carilion Research Institute, Roanoke, VA, USA
- Virginia Tech School of Neuroscience, Blacksburg, VA, USA
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39
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Schießl IM, Castrop H. Deep insights: intravital imaging with two-photon microscopy. Pflugers Arch 2016; 468:1505-16. [PMID: 27352273 DOI: 10.1007/s00424-016-1832-7] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 04/26/2016] [Indexed: 01/03/2023]
Abstract
Intravital multiphoton microscopy is widely used to assess the structure and function of organs in live animals. Although different tissues vary in their accessibility for intravital multiphoton imaging, considerable progress has been made in the imaging quality of all tissues due to substantial technical improvements in the relevant imaging components, such as optics, excitation laser, detectors, and signal analysis software. In this review, we provide an overview of the technical background of intravital multiphoton microscopy. Then, we note a few seminal findings that were made through the use of multiphoton microscopy. Finally, we address the technical limitations of the method and provide an outlook for how these limitations may be overcome through future technical developments.
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Affiliation(s)
- Ina Maria Schießl
- Institute of Physiology, University of Regensburg, Universitätsstr. 31, 93040, Regensburg, Germany.
| | - Hayo Castrop
- Institute of Physiology, University of Regensburg, Universitätsstr. 31, 93040, Regensburg, Germany
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40
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Reactive gliosis in the pathogenesis of CNS diseases. Biochim Biophys Acta Mol Basis Dis 2016; 1862:483-91. [DOI: 10.1016/j.bbadis.2015.11.014] [Citation(s) in RCA: 157] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Revised: 11/19/2015] [Accepted: 11/30/2015] [Indexed: 01/11/2023]
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41
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Al-Ali H, Beckerman SR, Bixby JL, Lemmon VP. In vitro models of axon regeneration. Exp Neurol 2016; 287:423-434. [PMID: 26826447 DOI: 10.1016/j.expneurol.2016.01.020] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2015] [Revised: 01/20/2016] [Accepted: 01/25/2016] [Indexed: 12/31/2022]
Abstract
A variety of in vitro models have been developed to understand the mechanisms underlying the regenerative failure of central nervous system (CNS) axons, and to guide pre-clinical development of regeneration-promoting therapeutics. These range from single-cell based assays that typically focus on molecular mechanisms to organotypic assays that aim to recapitulate in vivo behavior. By utilizing a combination of models, researchers can balance the speed, convenience, and mechanistic resolution of simpler models with the biological relevance of more complex models. This review will discuss a number of models that have been used to build our understanding of the molecular mechanisms of CNS axon regeneration.
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Affiliation(s)
- Hassan Al-Ali
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Samuel R Beckerman
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - John L Bixby
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Center for Computational Sciences, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Molecular & Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
| | - Vance P Lemmon
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Center for Computational Sciences, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
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42
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Johnson KM, Crocker SJ. TIMP-1 couples RhoK activation to IL-1β-induced astrocyte responses. Neurosci Lett 2015; 609:165-70. [PMID: 26484505 DOI: 10.1016/j.neulet.2015.10.038] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/21/2015] [Accepted: 10/13/2015] [Indexed: 12/27/2022]
Abstract
Interleukin-1β (IL-1β) is a pleotropic cytokine known to influence the central nervous system (CNS) responses to injury or infection. IL-1β also directly induces astrocytic expression of tissue inhibitor of metalloproteinases (TIMP)-1, a potent trophic factor and regulator of matrix metalloproteinase activity. In this study, we examined the functional relationship between IL-1β and TIMP-1 and determined that the behavior of astrocytes in response to IL-1β is determined by TIMP-1 expression. Using primary astrocytes from C57Bl/6 mice, we found astrocytes from wildtype (Wt) mice exhibited a robust wound healing response to a scratch wound that was arrested in response to IL-1β. In contrast, TIMP-1 knockout (TIMP-1KO) astrocytes, exhibited minimal response to the scratch wound but an accelerated response following IL-1β-treatment. We also determined that the scratch wound effect in Wt cultures was attenuated by inhibition of Rho kinase but amplified in the TIMP-1KO cultures. We propose that the specific induction of TIMP-1 from astrocytes in response to IL-1β reflects a previously unrecognized physiological relationship where the directionality of astrocytic behavior is determined by the actions of TIMP‑1. These findings may provide additional insight into glial responses in the context of neuropathology where expression of TIMP-1 may vary and astrocytic responses may be impacted by the inflammatory milieu of the CNS.
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Affiliation(s)
- Kasey M Johnson
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, United States
| | - Stephen J Crocker
- Department of Neuroscience, University of Connecticut School of Medicine, Farmington, CT, United States.
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43
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Correale J, Farez MF. The Role of Astrocytes in Multiple Sclerosis Progression. Front Neurol 2015; 6:180. [PMID: 26347709 PMCID: PMC4539519 DOI: 10.3389/fneur.2015.00180] [Citation(s) in RCA: 175] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2015] [Accepted: 08/03/2015] [Indexed: 01/03/2023] Open
Abstract
Multiple sclerosis (MS) is an inflammatory disorder causing central nervous system (CNS) demyelination and axonal injury. Although its etiology remains elusive, several lines of evidence support the concept that autoimmunity plays a major role in disease pathogenesis. The course of MS is highly variable; nevertheless, the majority of patients initially present a relapsing–remitting clinical course. After 10–15 years of disease, this pattern becomes progressive in up to 50% of untreated patients, during which time clinical symptoms slowly cause constant deterioration over a period of many years. In about 15% of MS patients, however, disease progression is relentless from disease onset. Published evidence supports the concept that progressive MS reflects a poorly understood mechanism of insidious axonal degeneration and neuronal loss. Recently, the type of microglial cell and of astrocyte activation and proliferation observed has suggested contribution of resident CNS cells may play a critical role in disease progression. Astrocytes could contribute to this process through several mechanisms: (a) as part of the innate immune system, (b) as a source of cytotoxic factors, (c) inhibiting remyelination and axonal regeneration by forming a glial scar, and (d) contributing to axonal mitochondrial dysfunction. Furthermore, regulatory mechanisms mediated by astrocytes can be affected by aging. Notably, astrocytes might also limit the detrimental effects of pro-inflammatory factors, while providing support and protection for oligodendrocytes and neurons. Because of the dichotomy observed in astrocytic effects, the design of therapeutic strategies targeting astrocytes becomes a challenging endeavor. Better knowledge of molecular and functional properties of astrocytes, therefore, should promote understanding of their specific role in MS pathophysiology, and consequently lead to development of novel and more successful therapeutic approaches.
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Affiliation(s)
- Jorge Correale
- Department of Neurology, Institute for Neurological Research Dr. Raúl Carrea, FLENI , Buenos Aires , Argentina
| | - Mauricio F Farez
- Department of Neurology, Institute for Neurological Research Dr. Raúl Carrea, FLENI , Buenos Aires , Argentina
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44
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Jahn HM, Scheller A, Kirchhoff F. Genetic control of astrocyte function in neural circuits. Front Cell Neurosci 2015; 9:310. [PMID: 26347607 PMCID: PMC4538289 DOI: 10.3389/fncel.2015.00310] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 07/27/2015] [Indexed: 11/21/2022] Open
Abstract
During the last two decades numerous genetic approaches affecting cell function in vivo have been developed. Current state-of-the-art technology permits the selective switching of gene function in distinct cell populations within the complex organization of a given tissue parenchyma. The tamoxifen-inducible Cre/loxP gene recombination and the doxycycline-dependent modulation of gene expression are probably the most popular genetic paradigms. Here, we will review applications of these two strategies while focusing on the interactions of astrocytes and neurons in the central nervous system (CNS) and their impact for the whole organism. Abolishing glial sensing of neuronal activity by selective deletion of glial transmitter receptors demonstrated the impact of astrocytes for higher cognitive functions such as learning and memory, or the more basic body control of muscle coordination. Interestingly, also interfering with glial output, i.e., the release of gliotransmitters can drastically change animal’s physiology like sleeping behavior. Furthermore, such genetic approaches have also been used to restore astrocyte function. In these studies two alternatives were employed to achieve proper genetic targeting of astrocytes: transgenes using the promoter of the human glial fibrillary acidic protein (GFAP) or homologous recombination into the glutamate-aspartate transporter (GLAST) locus. We will highlight their specific properties that could be relevant for their use.
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Affiliation(s)
- Hannah M Jahn
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland Homburg, Germany
| | - Anja Scheller
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland Homburg, Germany
| | - Frank Kirchhoff
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland Homburg, Germany
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45
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Beckerman SR, Jimenez JE, Shi Y, Al-Ali H, Bixby JL, Lemmon VP. Phenotypic assays to identify agents that induce reactive gliosis: a counter-screen to prioritize compounds for preclinical animal studies. Assay Drug Dev Technol 2015; 13:377-88. [PMID: 26230074 DOI: 10.1089/adt.2015.654] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Astrocyte phenotypes change in a process called reactive gliosis after traumatic central nervous system (CNS) injury. Astrogliosis is characterized by expansion of the glial fibrillary acidic protein (GFAP) cytoskeleton, adoption of stellate morphologies, and differential expression of some extracellular matrix molecules. The astrocytic response immediately after injury is beneficial, but in the chronic injury phase, reactive astrocytes produce inhibitory factors (i.e., chondroitin sulfate proteoglycans [CSPGs]) that limit the regrowth of injured axons. There are no drugs that promote axon regeneration or functional recovery after CNS trauma in humans. To develop novel therapeutics for the injured CNS, we screened various libraries in a phenotypic assay to identify compounds that promote neurite outgrowth. However, the effects these compounds have on astrocytes are unknown. Specifically, we were interested in whether compounds could alter astrocytes in a manner that mimics the glial reaction to injury. To test this hypothesis, we developed cell-based phenotypic bioassays to measure changes in (1) GFAP morphology/localization and (2) CSPG expression/immunoreactivity from primary astrocyte cultures. These assays were optimized for six-point dose-response experiments in 96-well plates. The GFAP morphology assay is suitable for counter-screening with a Z-factor of 0.44±0.03 (mean±standard error of the mean; N=3 biological replicates). The CSPG assay is reproducible and informative, but does not satisfy common metrics for a "screenable" assay. As proof of principle, we tested a small set of hit compounds from our neurite outgrowth bioassay and identified one that can enhance axon growth without exacerbating the deleterious characteristics of reactive gliosis.
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Affiliation(s)
- Samuel R Beckerman
- 1 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| | - Joaquin E Jimenez
- 1 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| | - Yan Shi
- 1 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| | - Hassan Al-Ali
- 1 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida
| | - John L Bixby
- 1 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida.,2 Center for Computational Science, University of Miami, Coral Gables, Florida.,3 Department of Neurological Surgery, University of Miami Miller School of Medicine , Miami, Florida.,4 Department of Molecular & Cellular Pharmacology, University of Miami Miller School of Medicine , Miami, Florida
| | - Vance P Lemmon
- 1 The Miami Project to Cure Paralysis, University of Miami Miller School of Medicine , Miami, Florida.,2 Center for Computational Science, University of Miami, Coral Gables, Florida.,3 Department of Neurological Surgery, University of Miami Miller School of Medicine , Miami, Florida
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Johnson KM, Milner R, Crocker SJ. Extracellular matrix composition determines astrocyte responses to mechanical and inflammatory stimuli. Neurosci Lett 2015; 600:104-9. [PMID: 26067407 DOI: 10.1016/j.neulet.2015.06.013] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Revised: 06/03/2015] [Accepted: 06/05/2015] [Indexed: 01/19/2023]
Abstract
Astrocytes perform critical homeostatic physiological functions in the central nervous system (CNS) and are robustly responsive to injury, inflammation, or infection. We hypothesized that the components of the extracellular matrix (ECM), which are known to vary during development and in response to disease, determine astrocytic responses to injury and inflammation. We examined the response of primary astrocyte cultures grown on different ECM proteins to a mechanical wound (i.e., scratch). ECM substrates selected were laminin (Ln), vitronectin (Vn), fibronectin (Fn) or Tenascin C (TnC). We found that regrowth of the scratch wound was ECM dependent: recovery was arrested on fibronectin (Fn), almost complete on either Vn, Ln, or TnC. To determine whether ECM responses were also influenced by inflammation, we treated ECM plated cultures with interleukin-1β (IL-1β). We found that IL-1β arrested astrocyte growth on Ln, accelerated astrocyte growth on Fn and had no significant effect on astrocyte growth on TnC or Vn. We also determined that blocking β1integrins, the major class of receptors for all ECM proteins tested, prevented the robust response of astrocytes exposed to TnC, Ln and Vn, and also inhibited the robust effect of IL-1β to stimulate astrocyte growth on Fn. In addition, we evaluated downstream targets of integrin signaling, specifically the mammalian target of rapamycin (mTOR), and determined that activation of this pathway contributed to the response of astrocytes grown on TnC, but not on Ln, Vn or Fn. These findings provide new insights into the role of ECM as a source of heterogeneity of glial responses that may have important implications for neuropathological sequelae.
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Affiliation(s)
- Kasey M Johnson
- Department of Neuroscience,University of Connecticut School of Medicine, Farmington, CT, USA
| | - Richard Milner
- Department of Experimental Medicine, The Scripps Research Institute, La Jolla, CA, USA
| | - Stephen J Crocker
- Department of Neuroscience,University of Connecticut School of Medicine, Farmington, CT, USA.
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Karve IP, Taylor JM, Crack PJ. The contribution of astrocytes and microglia to traumatic brain injury. Br J Pharmacol 2015; 173:692-702. [PMID: 25752446 DOI: 10.1111/bph.13125] [Citation(s) in RCA: 414] [Impact Index Per Article: 46.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2014] [Revised: 02/09/2015] [Accepted: 02/18/2015] [Indexed: 12/13/2022] Open
Abstract
Traumatic brain injury (TBI) represents a major cause of death and disability in developed countries. Brain injuries are highly heterogeneous and can also trigger other neurological complications, including epilepsy, depression and dementia. The initial injury often leads to the development of secondary sequelae; cellular hyperexcitability, vasogenic and cytotoxic oedema, hypoxia-ischaemia, oxidative stress and inflammation, all of which influence expansion of the primary lesion. It is widely known that inflammatory events in the brain following TBI contribute to the widespread cell death and chronic tissue degeneration. Neuroinflammation is a multifaceted response involving a number of cell types, both within the CNS and in the peripheral circulation. Astrocytes and microglia, cells of the CNS, are considered key players in initiating an inflammatory response after injury. These cells are capable of secreting various cytokines, chemokines and growth factors, and following injury to the CNS, undergo changes in morphology. Ultimately, these changes can influence the local microenvironment and thus determine the extent of damage and subsequent repair. This review will focus on the roles of microglia and astrocytes following TBI, highlighting some of the key processes, pathways and mediators involved in this response. Additionally, both the beneficial and the detrimental aspects of these cellular responses will be examined using evidence from animal models and human post-mortem TBI studies.
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Affiliation(s)
- Ila P Karve
- Neuropharmacology Laboratory, Department of Pharmacology, University of Melbourne, Melbourne, Vic., Australia
| | - Juliet M Taylor
- Neuropharmacology Laboratory, Department of Pharmacology, University of Melbourne, Melbourne, Vic., Australia
| | - Peter J Crack
- Neuropharmacology Laboratory, Department of Pharmacology, University of Melbourne, Melbourne, Vic., Australia
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Robel S, Buckingham SC, Boni JL, Campbell SL, Danbolt NC, Riedemann T, Sutor B, Sontheimer H. Reactive astrogliosis causes the development of spontaneous seizures. J Neurosci 2015; 35:3330-45. [PMID: 25716834 PMCID: PMC4339349 DOI: 10.1523/jneurosci.1574-14.2015] [Citation(s) in RCA: 189] [Impact Index Per Article: 21.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2014] [Revised: 12/16/2014] [Accepted: 01/12/2015] [Indexed: 11/21/2022] Open
Abstract
Epilepsy is one of the most common chronic neurologic diseases, yet approximately one-third of affected patients do not respond to anticonvulsive drugs that target neurons or neuronal circuits. Reactive astrocytes are commonly found in putative epileptic foci and have been hypothesized to be disease contributors because they lose essential homeostatic capabilities. However, since brain pathology induces astrocytes to become reactive, it is difficult to distinguish whether astrogliosis is a cause or a consequence of epileptogenesis. We now present a mouse model of genetically induced, widespread chronic astrogliosis after conditional deletion of β1-integrin (Itgβ1). In these mice, astrogliosis occurs in the absence of other pathologies and without BBB breach or significant inflammation. Electroencephalography with simultaneous video recording revealed that these mice develop spontaneous seizures during the first six postnatal weeks of life and brain slices show neuronal hyperexcitability. This was not observed in mice with neuronal-targeted β1-integrin deletion, supporting the hypothesis that astrogliosis is sufficient to induce epileptic seizures. Whole-cell patch-clamp recordings from astrocytes further suggest that the heightened excitability was associated with impaired astrocytic glutamate uptake. Moreover, the relative expression of the cation-chloride cotransporters (CCC) NKCC1 (Slc12a2) and KCC2 (Slc12a5), which are responsible for establishing the neuronal Cl(-) gradient that governs GABAergic inhibition were altered and the NKCC1 inhibitor bumetanide eliminated seizures in a subgroup of mice. These data suggest that a shift in the relative expression of neuronal NKCC1 and KCC2, similar to that observed in immature neurons during development, may contribute to astrogliosis-associated seizures.
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Affiliation(s)
- Stefanie Robel
- Department of Neurobiology, Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35209,
| | - Susan C Buckingham
- Department of Neurobiology, Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35209
| | - Jessica L Boni
- Department of Neurobiology, Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35209
| | - Susan L Campbell
- Department of Neurobiology, Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35209
| | - Niels C Danbolt
- Department of Anatomy, Institute of Basic Medical Sciences, University of Oslo, 0317 Oslo, Norway, and
| | - Therese Riedemann
- Institute of Physiology, Department of Physiological Genomics, Ludwig-Maximilians-University of Munich, 80336 Munich, Germany
| | - Bernd Sutor
- Institute of Physiology, Department of Physiological Genomics, Ludwig-Maximilians-University of Munich, 80336 Munich, Germany
| | - Harald Sontheimer
- Department of Neurobiology, Center for Glial Biology in Medicine, University of Alabama at Birmingham, Birmingham, Alabama 35209
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49
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Schweinhuber SK, Meßerschmidt T, Hänsch R, Korte M, Rothkegel M. Profilin isoforms modulate astrocytic morphology and the motility of astrocytic processes. PLoS One 2015; 10:e0117244. [PMID: 25629407 PMCID: PMC4309604 DOI: 10.1371/journal.pone.0117244] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2014] [Accepted: 12/22/2014] [Indexed: 01/17/2023] Open
Abstract
The morphology of astrocytic processes determines their close structural association with synapses referred to as the ‘tripartite synapse’. Concerted morphological plasticity processes at tripartite synapses are supposed to shape neuronal communication. Morphological changes in astrocytes as well as the motility of astrocytic processes require remodeling of the actin cytoskeleton. Among the regulators of fast timescale actin-based motility, the actin binding protein profilin 1 has recently been shown to control the activity-dependent outgrowth of astrocytic processes. Here, we demonstrate that cultured murine astrocytes in addition to the ubiquitous profilin 1 also express the neuronal isoform profilin 2a. To analyze the cellular function of both profilins in astrocytes, we took advantage of a shRNA mediated isoform-specific downregulation. Interestingly, consistent with earlier results in neurons, we found redundant as well as isoform-specific functions of both profilins in modulating cellular physiology. The knockdown of either profilin 1 or profilin 2a led to a significant decrease in cell spreading of astrocytes. In contrast, solely the knockdown of profilin 2a resulted in a significantly reduced morphological complexity of astrocytes in both dissociated and slice culture astrocytes. Moreover, both isoforms proved to be crucial for forskolin-induced astrocytic stellation. Furthermore, forskolin treatment resulted in isoform-specific changes in the phosphorylation level of profilin 1 and profilin 2a, leading to a PKA-dependent phosphorylation of profilin 2a. In addition, transwell assays revealed an involvement of both isoforms in the motility of astrocytic processes, while FRAP analysis displayed an isoform-specific role of profilin 1 in the regulation of actin dynamics in peripheral astrocytic processes. Taken together, we suggest profilin isoforms to be important modulators of astrocytic morphology and motility with overlapping as well as isoform-specific functions.
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Affiliation(s)
| | - Tania Meßerschmidt
- Cellular Neurobiology, Zoological Institute, TU Braunschweig, Braunschweig, Germany
| | - Robert Hänsch
- Molecular and Cell Biology of Plants, Institute of Plant Biology, TU Braunschweig, Braunschweig, Germany
| | - Martin Korte
- Cellular Neurobiology, Zoological Institute, TU Braunschweig, Braunschweig, Germany
| | - Martin Rothkegel
- Cellular Neurobiology, Zoological Institute, TU Braunschweig, Braunschweig, Germany
- * E-mail:
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50
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Pekny M, Pekna M. Astrocyte reactivity and reactive astrogliosis: costs and benefits. Physiol Rev 2014; 94:1077-98. [PMID: 25287860 DOI: 10.1152/physrev.00041.2013] [Citation(s) in RCA: 606] [Impact Index Per Article: 60.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Astrocytes are the most abundant cells in the central nervous system (CNS) that provide nutrients, recycle neurotransmitters, as well as fulfill a wide range of other homeostasis maintaining functions. During the past two decades, astrocytes emerged also as increasingly important regulators of neuronal functions including the generation of new nerve cells and structural as well as functional synapse remodeling. Reactive gliosis or reactive astrogliosis is a term coined for the morphological and functional changes seen in astroglial cells/astrocytes responding to CNS injury and other neurological diseases. Whereas this defensive reaction of astrocytes is conceivably aimed at handling the acute stress, limiting tissue damage, and restoring homeostasis, it may also inhibit adaptive neural plasticity mechanisms underlying recovery of function. Understanding the multifaceted roles of astrocytes in the healthy and diseased CNS will undoubtedly contribute to the development of treatment strategies that will, in a context-dependent manner and at appropriate time points, modulate reactive astrogliosis to promote brain repair and reduce the neurological impairment.
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Affiliation(s)
- Milos Pekny
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; and Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
| | - Marcela Pekna
- Center for Brain Repair and Rehabilitation, Department of Clinical Neuroscience and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy at the University of Gothenburg, Gothenburg, Sweden; and Florey Institute of Neuroscience and Mental Health, Parkville, Victoria, Australia
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