51
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Jiang S, Wang H, Zhou Q, Li Q, Liu N, Li Z, Chen C, Deng Y. Melatonin Ameliorates Axonal Hypomyelination of Periventricular White Matter by Transforming A1 to A2 Astrocyte via JAK2/STAT3 Pathway in Septic Neonatal Rats. J Inflamm Res 2021; 14:5919-5937. [PMID: 34803390 PMCID: PMC8595063 DOI: 10.2147/jir.s337499] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Accepted: 10/29/2021] [Indexed: 12/12/2022] Open
Abstract
Background Astrocyte A1/A2 phenotypes may play differential role in the pathogenesis of periventricular white matter (PWM) damage in septic postnatal rats. This study aimed to determine whether melatonin (MEL) would improve the axonal hypomyelination through shifting A1 astrocytes towards A2. Methods One-day-old Sprague-Dawley rats were divided into control, LPS, and LPS+MEL groups. Immunofluorescence was performed to detect C1q, IL-1α, TNF-α, IBA1, GFAP, MAG, C3 and S100A10 immunoreactivity in the PWM of neonatal rats. Electron microscopy was conducted to observe alterations of axonal myelin sheath in the PWM; moreover, myelin protein expression was assessed using in situ hybridization. The effects of MEL on neurological function were evaluated by behavioral tests. In vitro, A1 astrocytes were induced by IL-1α, C1q and TNF-α, and following which the effect of MEL on C3 and S100A10 expression was determined by Western blot and immunofluorescence. Results At 1 and 3 days after LPS injection, IBA1+ microglia in the PWM were significantly increased in cell numbers which generated excess amounts of IL-1α, TNF-α, and C1q. The number of A1 astrocytes was significantly increased at 7-28d after LPS injection. In rats given MEL treatment, the number of A1 astrocytes was significantly decreased, but that of A2 astrocytes, PLP+, MBP+ and MAG+ cells was increased. By electron microscopy, ultrastructural features of axonal hypomyelination were attenuated by MEL. Furthermore, MEL improved neurological dysfunction as evaluated by different neurological tests. In vitro, MEL decreased the C3 significantly, and upregulated expression of S100A10 in primary astrocytes subjected to IL-1α, TNF-α and C1q treatment. Importantly, JAK2/STAT3 signaling pathway was found to be involved in modulation of A1/A2 phenotype transformation. Conclusion MEL effectively alleviates PWMD of septic neonatal rats, which is most likely through modulating astrocyte phenotypic transformation from A1 to A2 via the MT1/JAK2/STAT3 pathway.
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Affiliation(s)
- Shuqi Jiang
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China
| | - Huifang Wang
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510515, People's Republic of China
| | - Qiuping Zhou
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China.,Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, 510641, People's Republic of China
| | - Qian Li
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510515, People's Republic of China
| | - Nan Liu
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China.,Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, School of Medicine, South China University of Technology, Guangzhou, 510641, People's Republic of China
| | - Zhenggong Li
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China
| | - Chunbo Chen
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China
| | - Yiyu Deng
- Department of Critical Care Medicine, Guangdong Provincial People's Hospital, Guangdong Academy of Medical Sciences, Guangzhou, 510080, People's Republic of China.,The Second School of Clinical Medicine, Southern Medical University, Guangzhou, 510515, People's Republic of China
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Hülskötter K, Jin W, Allnoch L, Hansmann F, Schmidtke D, Rohn K, Flügel A, Lühder F, Baumgärtner W, Herder V. Double-edged effects of tamoxifen-in-oil-gavage on an infectious murine model for multiple sclerosis. Brain Pathol 2021; 31:e12994. [PMID: 34137105 PMCID: PMC8549030 DOI: 10.1111/bpa.12994] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 05/05/2021] [Accepted: 05/06/2021] [Indexed: 12/13/2022] Open
Abstract
Tamoxifen gavage is a commonly used method to induce genetic modifications in cre-loxP systems. As a selective estrogen receptor modulator (SERM), the compound is known to have immunomodulatory and neuroprotective properties in non-infectious central nervous system (CNS) disorders. It can even cause complete prevention of lesion development as seen in experimental autoimmune encephalitis (EAE). The effect on infectious brain disorders is scarcely investigated. In this study, susceptible SJL mice were infected intracerebrally with Theiler's murine encephalomyelitis virus (TMEV) and treated three times with a tamoxifen-in-oil-gavage (TOG), resembling an application scheme for genetically modified mice, starting at 0, 18, or 38 days post infection (dpi). All mice developed 'TMEV-induced demyelinating disease' (TMEV-IDD) resulting in inflammation, axonal loss, and demyelination of the spinal cord. TOG had a positive effect on the numbers of oligodendrocytes and oligodendrocyte progenitor cells, irrespective of the time point of application, whereas late application (starting 38 dpi) was associated with increased demyelination of the spinal cord white matter 85 dpi. Furthermore, TOG had differential effects on the CD4+ and CD8+ T cell infiltration into the CNS, especially a long lasting increase of CD8+ cells was detected in the inflamed spinal cord, depending of the time point of TOG application. Number of TMEV-positive cells, astrogliosis, astrocyte phenotype, apoptosis, clinical score, and motor function were not measurably affected. These data indicate that tamoxifen gavage has a double-edged effect on TMEV-IDD with the promotion of oligodendrocyte differentiation and proliferation, but also increased demyelination, depending on the time point of application. The data of this study suggest that tamoxifen has also partially protective functions in infectious CNS disease. These effects should be considered in experimental studies using the cre-loxP system, especially in models investigating neuropathologies.
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Affiliation(s)
- Kirsten Hülskötter
- Department of PathologyUniversity of Veterinary Medicine HannoverHannoverGermany
- Center for Systems NeuroscienceHannoverGermany
| | - Wen Jin
- Department of PathologyUniversity of Veterinary Medicine HannoverHannoverGermany
- Center for Systems NeuroscienceHannoverGermany
| | - Lisa Allnoch
- Department of PathologyUniversity of Veterinary Medicine HannoverHannoverGermany
- Center for Systems NeuroscienceHannoverGermany
| | - Florian Hansmann
- Department of PathologyUniversity of Veterinary Medicine HannoverHannoverGermany
- Center for Systems NeuroscienceHannoverGermany
- Institute of Veterinary PathologyLeipzig UniversityLeipzigGermany
| | - Daniel Schmidtke
- Center for Systems NeuroscienceHannoverGermany
- Institute of ZoologyUniversity of Veterinary Medicine HannoverHannoverGermany
| | - Karl Rohn
- Institute of Biometry, Epidemiology, and Information ProcessingUniversity of Veterinary Medicine HannoverHannoverGermany
| | - Alexander Flügel
- Center for Systems NeuroscienceHannoverGermany
- Institute for Neuroimmunology and Multiple Sclerosis ResearchUniversity Medical Center GöttingenGöttingenGermany
| | - Fred Lühder
- Institute for Neuroimmunology and Multiple Sclerosis ResearchUniversity Medical Center GöttingenGöttingenGermany
| | - Wolfgang Baumgärtner
- Department of PathologyUniversity of Veterinary Medicine HannoverHannoverGermany
- Center for Systems NeuroscienceHannoverGermany
| | - Vanessa Herder
- Department of PathologyUniversity of Veterinary Medicine HannoverHannoverGermany
- Center for Systems NeuroscienceHannoverGermany
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Guo H, Fan Z, Wang S, Ma L, Wang J, Yu D, Zhang Z, Wu L, Peng Z, Liu W, Hou W, Cai Y. Astrocytic A1/A2 paradigm participates in glycogen mobilization mediated neuroprotection on reperfusion injury after ischemic stroke. J Neuroinflammation 2021; 18:230. [PMID: 34645472 PMCID: PMC8513339 DOI: 10.1186/s12974-021-02284-y] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Accepted: 09/27/2021] [Indexed: 12/25/2022] Open
Abstract
Background Astrocytic glycogen works as an essential energy reserve for surrounding neurons and is reported to accumulate excessively during cerebral ischemia/reperfusion (I/R) injury. Our previous study found that accumulated glycogen mobilization exhibits a neuroprotective effect against I/R damage. In addition, ischemia could transform astrocytes into A1-like (toxic) and A2-like (protective) subtypes. However, the underlying mechanism behind accumulated glycogen mobilization-mediated neuroprotection in cerebral reperfusion injury and its relationship with the astrocytic A1/A2 paradigm is unknown. Methods Astrocytic glycogen phosphorylase, the rate-limiting enzyme in glycogen mobilization, was specifically overexpressed and knocked down in mice and in cultured astrocytes. The I/R injury was imitated using a middle cerebral artery occlusion/reperfusion model in mice and an oxygen–glucose deprivation/reoxygenation model in cultured cells. Alterations in A1-like and A2-like astrocytes and the expression of phosphorylated nuclear transcription factor-κB (NF-κB) and phosphorylated signal transducer and activator of transcription 3 (STAT3) were determined by RNA sequencing, immunofluorescence and immunoblotting. Metabolites, including glycogen, NADPH, glutathione and reactive oxygen species (ROS), were analyzed by biochemical analysis. Results Here, we observed that astrocytic glycogen mobilization inhibited A1-like astrocytes and enhanced A2-like astrocytes after reperfusion in an experimental ischemic stroke model in vivo and in vitro. In addition, glycogen mobilization could enhance the production of NADPH and glutathione by the pentose phosphate pathway (PPP) and reduce ROS levels during reperfusion. NF-κB inhibition and STAT3 activation caused by a decrease in ROS levels were responsible for glycogen mobilization-induced A1-like and A2-like astrocyte transformation after I/R. The astrocytic A1/A2 paradigm is closely correlated with glycogen mobilization-mediated neuroprotection in cerebral reperfusion injury. Conclusions Our data suggest that ROS-mediated NF-κB inhibition and STAT3 activation are the key pathways for glycogen mobilization-induced neuroprotection and provide a promising metabolic target for brain reperfusion injury in ischemic stroke. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02284-y.
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Affiliation(s)
- Haiyun Guo
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Ze Fan
- Department of Anesthesiology, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Shiquan Wang
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Lina Ma
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Jin Wang
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Doutong Yu
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Zhen Zhang
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Lin Wu
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Zhengwu Peng
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Wenming Liu
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China
| | - Wugang Hou
- Department of Anesthesiology and Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.
| | - Yanhui Cai
- Department of Psychiatry, Xijing Hospital, Fourth Military Medical University, Xi'an, Shaanxi, China.
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Penning DH, Cazacu S, Brodie A, Jevtovic-Todorovic V, Kalkanis SN, Lewis M, Brodie C. Neuron-Glia Crosstalk Plays a Major Role in the Neurotoxic Effects of Ketamine via Extracellular Vesicles. Front Cell Dev Biol 2021; 9:691648. [PMID: 34604212 PMCID: PMC8481868 DOI: 10.3389/fcell.2021.691648] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2021] [Accepted: 08/06/2021] [Indexed: 02/02/2023] Open
Abstract
Background: There is a compelling evidence from animal models that early exposure to clinically relevant general anesthetics (GAs) interferes with brain development, resulting in long-lasting cognitive impairments. Human studies have been inconclusive and are challenging due to numerous confounding factors. Here, we employed primary human neural cells to analyze ketamine neurotoxic effects focusing on the role of glial cells and their activation state. We also explored the roles of astrocyte-derived extracellular vesicles (EVs) and different components of the brain-derived neurotrophic factor (BDNF) pathway. Methods: Ketamine effects on cell death were analyzed using live/dead assay, caspase 3 activity and PARP-1 cleavage. Astrocytic and microglial cell differentiation was determined using RT-PCR, ELISA and phagocytosis assay. The impact of the neuron-glial cell interactions in the neurotoxic effects of ketamine was analyzed using transwell cultures. In addition, the role of isolated and secreted EVs in this cross-talk were studied. The expression and function of different components of the BDNF pathway were analyzed using ELISA, RT-PCR and gene silencing. Results: Ketamine induced neuronal and oligodendrocytic cell apoptosis and promoted pro-inflammatory astrocyte (A1) and microglia (M1) phenotypes. Astrocytes and microglia enhanced the neurotoxic effects of ketamine on neuronal cells, whereas neurons increased oligodendrocyte cell death. Ketamine modulated different components in the BDNF pathway: decreasing BDNF secretion in neurons and astrocytes while increasing the expression of p75 in neurons and that of BDNF-AS and pro-BDNF secretion in both neurons and astrocytes. We demonstrated an important role of EVs secreted by ketamine-treated astrocytes in neuronal cell death and a role for EV-associated BDNF-AS in this effect. Conclusions: Ketamine exerted a neurotoxic effect on neural cells by impacting both neuronal and non-neuronal cells. The BDNF pathway and astrocyte-derived EVs represent important mediators of ketamine effects. These results contribute to a better understanding of ketamine neurotoxic effects in humans and to the development of potential approaches to decrease its neurodevelopmental impact.
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Affiliation(s)
- Donald H Penning
- Department of Anesthesiology, Pain Management and Perioperative Medicine, Henry Ford Hospital, Detroit, MI, United States.,Department of Neurosurgery, Henry Ford Health System, Detroit, MI, United States
| | - Simona Cazacu
- Department of Anesthesiology, Pain Management and Perioperative Medicine, Henry Ford Hospital, Detroit, MI, United States.,Department of Neurosurgery, Henry Ford Health System, Detroit, MI, United States
| | | | - Vesna Jevtovic-Todorovic
- Department of Anesthesiology, University of Colorado School of Medicine, Aurora, CO, United States
| | - Steve N Kalkanis
- Department of Neurosurgery, Henry Ford Health System, Detroit, MI, United States
| | - Michael Lewis
- Department of Anesthesiology, Pain Management and Perioperative Medicine, Henry Ford Hospital, Detroit, MI, United States
| | - Chaya Brodie
- Department of Neurosurgery, Henry Ford Health System, Detroit, MI, United States.,Faculty of Life Sciences, Bar-Ilan University, Ramat Gan, Israel
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55
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Davidson JO, Gonzalez F, Gressens P, Gunn AJ. Update on mechanisms of the pathophysiology of neonatal encephalopathy. Semin Fetal Neonatal Med 2021; 26:101267. [PMID: 34274259 DOI: 10.1016/j.siny.2021.101267] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Therapeutic hypothermia is now well established to significantly improve survival without disability after neonatal encephalopathy (NE). To further improve outcomes, we need to better understand the mechanisms of brain injury. The central finding, which offers the potential for neuroprotective and neurorestorative interventions, is that brain damage after perinatal hypoxia-ischemia evolves slowly over time. Although brain cells may die during profound hypoxia-ischemia, even after surprisingly severe insults many cells show transient recovery of oxidative metabolism during a "latent" phase characterized by actively suppressed neural metabolism and activity. Critically, after moderate to severe hypoxia-ischemia, this transient recovery is followed after ~6 h by a phase of secondary deterioration, with delayed seizures, failure of mitochondrial function, cytotoxic edema, and cell death over ~72 h. This is followed by a tertiary phase of remodeling and recovery. This review discusses the mechanisms of injury that occur during the primary, latent, secondary and tertiary phases of injury and potential treatments that target one or more of these phases. By analogy with therapeutic hypothermia, treatment as early as possible in the latent phase is likely to have the greatest potential to prevent injury ("neuroprotection"). In the secondary phase of injury, anticonvulsants can attenuate seizures, but show limited neuroprotection. Encouragingly, there is now increasing preclinical evidence that late, neurorestorative interventions have potential to improve long-term outcomes.
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Affiliation(s)
- Joanne O Davidson
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.
| | - Fernando Gonzalez
- Department of Pediatrics, University of California, San Francisco, CA, USA.
| | | | - Alistair J Gunn
- Fetal Physiology and Neuroscience Group, Department of Physiology, The University of Auckland, Auckland, New Zealand.
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Wang T, Sun Q, Yang J, Wang G, Zhao F, Chen Y, Jin Y. Reactive astrocytes induced by 2-chloroethanol modulate microglia polarization through IL-1β, TNF-α, and iNOS upregulation. Food Chem Toxicol 2021; 157:112550. [PMID: 34517076 DOI: 10.1016/j.fct.2021.112550] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2021] [Revised: 09/02/2021] [Accepted: 09/08/2021] [Indexed: 01/06/2023]
Abstract
The synthetic organic chemical, 1,2-dichloroethane (1,2-DCE), can cause brain edemas under subacute poisoning. Our previous studies indicated that neuroinflammation could be induced due to astrocytes and microglia activation during brain edemas in 1,2-DCE-intoxicated mice. However, the crosstalk between these two glial cells in 1,2-DCE-induced neuroinflammation remained unclear. In this study, primary cultured rat astrocytes and microglia, as well as an immortalized microglia cell line were employed to study the effects of 2-chloroethanol (2-CE, a 1,2-DCE intermediate metabolite in vivo) treated astrocytes on microglia polarization. Our current results revealed that 2-CE treated rat astrocytes were activated through p38 mitogen-activated protein kinase (p38 MAPK)/nuclear factor-κB (NF-κB), and activator protein-1 (AP-1) signaling pathways. Theses pathways were triggered by reactive oxygen species (ROS) produced during 2-CE metabolism. Also, astrocytes were more sensitive to 2-CE effects than microglia. Interleukin-1β (IL-1β), tumor necrosis factor-α (TNF-α), and inducible nitric oxide synthase (iNOS) expressions were upregulated in 2-CE-induced reactive astrocytes, enhancing IL-1β, TNF-α, and nitric oxide (NO) excretions, which stimulated microglia polarization. Therefore, the neuroinflammation induced by 1,2-DCE in mice's brains is probably triggered by reactive astrocytes.
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Affiliation(s)
- Tong Wang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, China
| | - Qi Sun
- Department of Child and Adolescent Health, China Medical University, Shenyang, China
| | - Jinhan Yang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, China
| | - Gaoyang Wang
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, China
| | - Fenghong Zhao
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, China
| | - Yuhua Chen
- Department of Developmental Biology, Key Laboratory of Cell Biology, Ministry of Public Health and Key Laboratory of Medical Cell Biology, Ministry of Education, China Medical University, Shenyang, China
| | - Yaping Jin
- Department of Occupational and Environmental Health, School of Public Health, China Medical University, Shenyang, China.
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Liu Q, Bhuiyan MIH, Liu R, Song S, Begum G, Young CB, Foley LM, Chen F, Hitchens TK, Cao G, Chattopadhyay A, He L, Sun D. Attenuating vascular stenosis-induced astrogliosis preserves white matter integrity and cognitive function. J Neuroinflammation 2021; 18:187. [PMID: 34454529 PMCID: PMC8403348 DOI: 10.1186/s12974-021-02234-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/04/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Chronic cerebral hypoperfusion (CCH) causes white matter damage and cognitive impairment, in which astrogliosis is the major pathology. However, underlying cellular mechanisms are not well defined. Activation of Na+/H+ exchanger-1 (NHE1) in reactive astrocytes causes astrocytic hypertrophy and swelling. In this study, we examined the role of NHE1 protein in astrogliosis, white matter demyelination, and cognitive function in a murine CCH model with bilateral carotid artery stenosis (BCAS). METHODS Sham, BCAS, or BCAS mice receiving vehicle or a selective NHE1 inhibitor HOE642 were monitored for changes of the regional cerebral blood flow and behavioral performance for 28 days. Ex vivo MRI-DTI was subsequently conducted to detect brain injury and demyelination. Astrogliosis and demyelination were further examined by immunofluorescence staining. Astrocytic transcriptional profiles were analyzed with bulk RNA-sequencing and RT-qPCR. RESULTS Chronic cerebral blood flow reduction and spatial working memory deficits were detected in the BCAS mice, along with significantly reduced mean fractional anisotropy (FA) values in the corpus callosum, external capsule, and hippocampus in MRI DTI analysis. Compared with the sham control mice, the BCAS mice displayed demyelination and axonal damage and increased GFAP+ astrocytes and Iba1+ microglia. Pharmacological inhibition of NHE1 protein with its inhibitor HOE642 prevented the BCAS-induced gliosis, damage of white matter tracts and hippocampus, and significantly improved cognitive performance. Transcriptome and immunostaining analysis further revealed that NHE1 inhibition specifically attenuated pro-inflammatory pathways and NADPH oxidase activation. CONCLUSION Our study demonstrates that NHE1 protein is involved in astrogliosis with pro-inflammatory transformation induced by CCH, and its blockade has potentials for reducing astrogliosis, demyelination, and cognitive impairment.
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Affiliation(s)
- Qian Liu
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
- Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
| | - Mohammad Iqbal H Bhuiyan
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
- Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
| | - Ruijia Liu
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
- Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
| | - Shanshan Song
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
- Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
| | - Gulnaz Begum
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
- Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
| | - Cullen B Young
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
- Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
| | - Lesley M Foley
- Animal Imaging Center, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
| | - Fenghua Chen
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
| | - T Kevin Hitchens
- Animal Imaging Center, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
- Department of Neurobiology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
| | - Guodong Cao
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA
- VA Pittsburgh Healthcare System, Geriatric Research Education and Clinical Center, Pittsburgh, Pennsylvania, 15240, USA
| | - Ansuman Chattopadhyay
- Molecular Biology-Information Service, Health Sciences Library System, University of Pittsburgh, Pittsburgh, Pennsylvania, 15261, USA
| | - Li He
- Department of Neurology, West China Hospital, Sichuan University, Chengdu, 610041, Sichuan, China.
| | - Dandan Sun
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA.
- Pittsburgh Institute for Neurodegenerative Disorders, University of Pittsburgh, Pittsburgh, Pennsylvania, 15213, USA.
- VA Pittsburgh Healthcare System, Geriatric Research Education and Clinical Center, Pittsburgh, Pennsylvania, 15240, USA.
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Chen MM, Hu ZL, Ding JH, Du RH, Hu G. Astrocytic Kir6.1 deletion aggravates neurodegeneration in the lipopolysaccharide-induced mouse model of Parkinson's disease via astrocyte-neuron cross talk through complement C3-C3R signaling. Brain Behav Immun 2021; 95:310-320. [PMID: 33838249 DOI: 10.1016/j.bbi.2021.04.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/19/2021] [Accepted: 04/03/2021] [Indexed: 12/17/2022] Open
Abstract
Complement pathway over-activation has been implicated in a variety of neurological diseases. However, the signaling pathways governing astrocytic complement activation in Parkinson's disease (PD) are poorly understood. Kir6.1, a pore-forming subunit of ATP-sensitive potassium (K-ATP) channel, is prominently expressed in astrocytes and exhibits anti-inflammatory effects. Therefore, we hypothesize that Kir6.1/K-ATP channel may regulate astrocytic complement activation in the pathogenesis of PD. In this study, astrocytic Kir6.1 knockout (KO) mice were used to examine the effect of astrocytic Kir6.1/K-ATP channel on astrocytic complement activation triggered by the lipopolysaccharide (LPS). Here, we found that astrocytic Kir6.1 KO mice showed more dopaminergic neuron loss and more astrocyte reactivity in substantia nigra compacta than controls. We also found that astrocytic Kir6.1 KO increased the expression of complement C3 in astrocytes in LPS-induced mouse model of PD. Mechanistically, astrocytic Kir6.1 KO promoted astroglial NF-κB activation to elicit extracellular release of C3, which in turn interacted with neuronal C3aR to induce neuron death. Blocking complement function by NF-κB inhibitor or C3aR antagonist rescued the aggravated neuron death induced by Kir6.1 KO. Collectively, our findings reveal that astrocytic Kir6.1/K-ATP channel prevents neurodegeneration in PD via astrocyte-neuron cross talk through NF-κB/C3/C3aR signaling and suggest that targeting astroglial Kir6.1/K-ATP channel-NF-κB-C3-neuronal C3aR signaling represents a novel therapeutic strategy for PD.
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Affiliation(s)
- Miao-Miao Chen
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu 211166, PR China
| | - Zhao-Li Hu
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu 211166, PR China
| | - Jian-Hua Ding
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu 211166, PR China
| | - Ren-Hong Du
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu 211166, PR China.
| | - Gang Hu
- Jiangsu Key Laboratory of Neurodegeneration, Department of Pharmacology, Nanjing Medical University, 101 Longmian Avenue, Nanjing, Jiangsu 211166, PR China; Department of Pharmacology, Nanjing University of Chinese Medicine, 138 Xianlin Avenue, Nanjing, Jiangsu 210023, PR China.
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59
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Yu B, Yao Y, Zhang X, Ruan M, Zhang Z, Xu L, Liang T, Lu J. Synergic Neuroprotection Between Ligusticum Chuanxiong Hort and Borneol Against Ischemic Stroke by Neurogenesis via Modulating Reactive Astrogliosis and Maintaining the Blood-Brain Barrier. Front Pharmacol 2021; 12:666790. [PMID: 34220506 PMCID: PMC8242197 DOI: 10.3389/fphar.2021.666790] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Accepted: 05/21/2021] [Indexed: 01/26/2023] Open
Abstract
Background:Ligusticum chuanxiong Hort (LCH) is a famous ethnomedicine in Asia known for its excellent output on stroke treatment, and borneol usually acts as an assistant for its reducing permeability of the blood–brain barrier (BBB) after stroke. Although their synergy against brain ischemia was verified in previous studies, the potential mechanism is still unknown. Methods: The research aimed to explore the exact synergic mechanisms between LCH and borneol on neurogenesis within the areas of the dentate gyrus and subventricular zone. After treating middle cerebral artery occlusion rats with LCH (0.1 g/kg) and/or borneol (0.08 g/kg), the neurological severity score, brain infarct ratio, Nissl staining, Evans blue permeability, BBB ultrastructure, and expressions of von Willebrand factor and tight junction–associated proteins were measured. Co-localizations of Nestin+/BrdU+ and doublecortin+/BrdU+, and expressions of neuronal nuclei (NeuN) and glial fibrillary acidic protein (GFAP) were observed under a fluorescence microscope. Moreover, astrocyte polarization markers of complement component 3 and pentraxin 3, and relevant neurotrophins were also detected by immunoblotting. Results: Basically, LCH and borneol had different focuses, although both of them decreased infarct areas, and increased quantity of Nissl bodies and expression of brain-derived neurotrophic factor. LCH increased the neurological severity score, NeuN+ cells, and the ratios of Nestin+/BrdU+ and doublecortin+/BrdU+, and decreased GFAP+ cells and ciliary neurotrophic factor expression. Additionally, it regulated the expressions of complement component 3 and pentraxin 3 to transform astrocyte phenotypes. Borneol improved BBB ultrastructure and increased the expressions of von Willebrand factor, tight junction–associated proteins, vascular endothelial growth factor, and vascular endothelial growth factor receptor 2. Unexpectedly, their combined therapy showed more obvious regulations on the Nissl score, Evans blue permeability, doublecortin+/BrdU+, NeuN+ cells, brain-derived neurotrophic factor, and vascular endothelial growth factor than both of their monotherapies. Conclusions: The results indicated that LCH and borneol were complementary to each other in attenuating brain ischemia by and large. LCH mainly promoted neural stem cell proliferation, neurogenesis, and mature neuron preservation, which was probably related to the transformation of reactive astrocytes from A1 subtype to A2, while borneol preferred to maintain the integrity of the BBB, which provided neurogenesis with a homeostatic environment.
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Affiliation(s)
- Bin Yu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yao Yao
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Xiaofeng Zhang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Ming Ruan
- School of Food Science, Nanjing Xiaozhuang University, Nanjing, China
| | - Zhennian Zhang
- Department of Encephalopathy, Nanjing Hospital of Traditional Chinese Medicine, Nanjing, China
| | - Li Xu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Tao Liang
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
| | - Jinfu Lu
- Jiangsu Key Laboratory for Pharmacology and Safety Evaluation of Chinese Materia Medica, Nanjing University of Chinese Medicine, Nanjing, China
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Fan YY, Huo J. A1/A2 astrocytes in central nervous system injuries and diseases: Angels or devils? Neurochem Int 2021; 148:105080. [PMID: 34048845 DOI: 10.1016/j.neuint.2021.105080] [Citation(s) in RCA: 89] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2021] [Revised: 05/07/2021] [Accepted: 05/22/2021] [Indexed: 02/07/2023]
Abstract
Astrocytes play a pivotal role in maintaining the central nervous system (CNS) homeostasis and function. In response to CNS injuries and diseases, reactive astrocytes are triggered. By purifying and genetically profiling reactive astrocytes, it has been now found that astrocytes can be activated into two polarization states: the neurotoxic or pro-inflammatory phenotype (A1) and the neuroprotective or anti-inflammatory phenotype (A2). Although the simple dichotomy of the A1/A2 phenotypes does not reflect the wide range of astrocytic phenotypes, it facilitates our understanding of the reactive state of astrocytes in various CNS disorders. This article reviews the recent evidences regarding A1/A2 astrocytes, including (a) the specific markers and morphological characteristics, (b) the effects of A1/A2 astrocytes on the neurovascular unit, and (c) the molecular mechanisms involved in the phenotypic switch of astrocytes. Although many questions remain, a deeper understanding of different phenotypic astrocytes will eventually help us to explore effective strategies for neurological disorders by targeting astrocytes.
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Affiliation(s)
- Yan-Ying Fan
- Department of Pharmacology, Basic Medical Sciences Center, Shanxi Medical University, Taiyuan, 030001, China; Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, 030001, China.
| | - Jing Huo
- Department of Pharmacology, Basic Medical Sciences Center, Shanxi Medical University, Taiyuan, 030001, China; Shanxi Provincial People's Hospital, Shanxi Medical University, Taiyuan, 030001, China
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Jiang T, Luo J, Pan X, Zheng H, Yang H, Zhang L, Hu X. Physical exercise modulates the astrocytes polarization, promotes myelin debris clearance and remyelination in chronic cerebral hypoperfusion rats. Life Sci 2021; 278:119526. [PMID: 33894268 DOI: 10.1016/j.lfs.2021.119526] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Revised: 04/01/2021] [Accepted: 04/13/2021] [Indexed: 10/21/2022]
Abstract
AIMS White matter damage is the main pathological feature of chronic cerebral hypoperfusion (CCH) and glial activation is crucial in this process. Physical exercise has protective effects on CCH, but the mechanism is unclear. Therefore, this study focuses on investigating the influence of physical exercise on activated astrocytes polarization and its role in CCH. MAIN METHODS Rats were given wheel running 48 h after 2VO (2 vessel occlusion) surgery. The cognitive function was evaluated by Morris water maze and novel object recognition test. Inflammatory cytokines expressions were detected by ELISA. Astrocytes polarization was analyzed by immunofluorescence. Myelin debris clearance and remyelination were detected by immunofluorescence and transmission electron microscopy. KEY FINDINGS Astrocytes were activated and mainly switched to A1 phenotype in rats 2 and 3 months after 2VO. Myelin debris deposition and limited remyelination can be observed at the corresponding time. Whereas physical exercise can improve the cognitive function of 2VO rats, downregulate the expression of inflammatory factors IL-1α, C1q and TNF, upregulate the release of TGFβ, and promote activated astrocytes transformation from A1 to A2 phenotype. In addition, it can also enhance myelin debris removal and remyelination. SIGNIFICANCE These findings suggest that the benefits of physical exercise on white matter repair and cognition improvement may be related to its regulation of astrocytes polarization, which contributes to myelin debris clearance and effective remyelination in CCH.
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Affiliation(s)
- Ting Jiang
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China; Department of Neurorehabilitation, Zhongnan Hospital of Wuhan University, Wuhan 430071, China
| | - Jing Luo
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China
| | - Xiaona Pan
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China
| | - Haiqing Zheng
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China
| | - Huaichun Yang
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China
| | - Liying Zhang
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China.
| | - Xiquan Hu
- Department of Rehabilitation Medicine, The Third Affiliated Hospital, Sun Yat-Sen University, Guangzhou 510630, China.
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Takai Y, Misu T, Suzuki H, Takahashi T, Okada H, Tanaka S, Okita K, Sasou S, Watanabe M, Namatame C, Matsumoto Y, Ono H, Kaneko K, Nishiyama S, Kuroda H, Nakashima I, Lassmann H, Fujihara K, Itoyama Y, Aoki M. Staging of astrocytopathy and complement activation in neuromyelitis optica spectrum disorders. Brain 2021; 144:2401-2415. [PMID: 33711152 DOI: 10.1093/brain/awab102] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Revised: 02/15/2021] [Accepted: 02/24/2021] [Indexed: 01/25/2023] Open
Abstract
Aquaporin 4 (AQP4)-IgG-positive neuromyelitis optica spectrum disorder (AQP4-IgG+NMOSD) is an autoimmune astrocytopathic disease pathologically characterized by the massive destruction and regeneration of astrocytes with diverse types of tissue injury with or without complement deposition. However, it is unknown whether this diversity is derived from differences in pathological processes or temporal changes. Furthermore, unlike for the demyelinating lesions in multiple sclerosis, there has been no staging of astrocytopathy in AQP4-IgG+NMOSD based on astrocyte morphology. Therefore, we classified astrocytopathy of the disease by comparing the characteristic features, such as AQP4 loss, inflammatory cell infiltration, complement deposition and demyelination activity, with the clinical phase. We performed histopathological analyses in eight autopsied cases of AQP4-IgG+NMOSD. There were six women and two men, with a median age of 56.5 years (range, 46-71 years) and a median disease duration of 62.5 months (range, 0.6-252 months). Astrocytopathy in AQP4-IgG+NMOSD was classified into the following four stages defined by the astrocyte morphology and immunoreactivity for glial fibrillary acidic protein (GFAP): (a) astrocyte lysis: Extensive loss of astrocytes with fragmented and/or dust-like particles; (b) progenitor recruitment: Loss of astrocytes except small nucleated cells with GFAP-positive fibre-forming foot processes; (c) protoplasmic gliosis: Presence of star-shaped astrocytes with abundant GFAP-reactive cytoplasm; and (d) fibrous gliosis: Lesions composed of densely packed mature astrocytes. The astrocyte lysis and progenitor recruitment stages dominated in clinically acute cases (within 2 months after the last recurrence). Findings common to both stages were the loss of AQP4, a decreased number of oligodendrocytes, the selective loss of myelin-associated glycoprotein and active demyelination with phagocytic macrophages. The infiltration of polymorphonuclear cells and T cells (CD4-dominant) and the deposition of activated complement (C9neo), which reflects the membrane attack complex, a hallmark of acute NMOSD lesions, were selectively observed in the astrocyte lysis stage (98.4% in astrocyte lysis, 1.6% in progenitor recruitment, and 0% in protoplasmic gliosis and fibrous gliosis). Although most of the protoplasmic gliosis and fibrous gliosis lesions were accompanied by inactive demyelinated lesions with a low amount of inflammatory cell infiltration, the deposition of complement degradation product (C3d) was observed in all four stages, even in fibrous gliosis lesions, suggesting the past or chronic occurrence of complement activation, which is a useful finding to distinguish chronic lesions in NMOSD from those in multiple sclerosis. Our staging of astrocytopathy is expected to be useful for understanding the unique temporal pathology of AQP4-IgG+NMOSD.
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Affiliation(s)
- Yoshiki Takai
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Tatsuro Misu
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Hiroyoshi Suzuki
- Department of Pathology, National Hospital Organization Sendai Medical Center, Sendai, 983-8520, Japan
| | - Toshiyuki Takahashi
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan.,Department of Neurology, National Hospital Organization Yonezawa National Hospital, Yonezawa, 992-1202, Japan
| | - Hiromi Okada
- Department of Surgical Pathology, Hokkaido University Hospital, Sapporo, 060-8648, Japan
| | - Shinya Tanaka
- Department of Cancer Pathology, Faculty of Medicine, Hokkaido University, Sapporo, 060-0808, Japan
| | - Kenji Okita
- Department of neurology, Nagoya City University Graduate School of Medical Sciences, Nagoya, 467-8601, Japan
| | - Shunichi Sasou
- Department of Pathology, Japanese Red Cross Society Hachinohe Hospital, Hachinohe, 039-1104, Japan
| | - Mika Watanabe
- Department of Pathology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Chihiro Namatame
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Yuki Matsumoto
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Hirohiko Ono
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Kimihiko Kaneko
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan.,Department of Neurology, Japanese Red Cross Ishinomaki Hospital, Ishinomaki, 986-8522, Japan
| | - Shuhei Nishiyama
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
| | - Hiroshi Kuroda
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan.,Department of Neurology, South Miyagi Medical Center, Shibata, 989-1253, Japan
| | - Ichiro Nakashima
- Department of Neurology, Tohoku Medical and Pharmaceutical University, Sendai, 983-8536, Japan
| | - Hans Lassmann
- Department of Neuroimmunology, Center for Brain Research, Medical University of Vienna, A-1090, Austria
| | - Kazuo Fujihara
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan.,Department of Multiple Sclerosis Therapeutics, Fukushima Medical University, Fukushima, 960-1295, Japan
| | - Yasuto Itoyama
- International University of Health and Welfare, Fukuoka, 814-0001, Japan
| | - Masashi Aoki
- Department of Neurology, Tohoku University Graduate School of Medicine, Sendai, 980-8574, Japan
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Quick S, Moss J, Rajani RM, Williams A. A Vessel for Change: Endothelial Dysfunction in Cerebral Small Vessel Disease. Trends Neurosci 2020; 44:289-305. [PMID: 33308877 DOI: 10.1016/j.tins.2020.11.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Revised: 09/24/2020] [Accepted: 11/11/2020] [Indexed: 01/08/2023]
Abstract
The blood vessels of the brain are lined with endothelial cells and it has been long known that these help to regulate blood flow to the brain. However, there is increasing evidence that these cells also interact with the surrounding brain tissue. These interactions change when the endothelial cells become dysfunctional and have an impact in diseases such as cerebral small vessel disease, the leading cause of vascular dementia. In this review, we focus on what endothelial dysfunction is, what causes it, how it leads to surrounding brain pathology, how researchers can investigate it with current models, and where this might lead in the future for dementia therapies.
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Affiliation(s)
- Sophie Quick
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, The University of Edinburgh, Edinburgh EH16 4UU, UK
| | - Jonathan Moss
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, The University of Edinburgh, Edinburgh EH16 4UU, UK
| | - Rikesh M Rajani
- UK Dementia Research Institute at UCL, University College London, London, UK
| | - Anna Williams
- Centre for Regenerative Medicine, Institute for Regeneration and Repair, The University of Edinburgh, Edinburgh EH16 4UU, UK.
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Abstract
Traumatic brain injury leads to cellular damage which in turn results in the rapid release of damage-associated molecular patterns (DAMPs) that prompt resident cells to release cytokines and chemokines. These in turn rapidly recruit neutrophils, which assist in limiting the spread of injury and removing cellular debris. Microglia continuously survey the CNS (central nervous system) compartment and identify structural abnormalities in neurons contributing to the response. After some days, when neutrophil numbers start to decline, activated microglia and astrocytes assemble at the injury site—segregating injured tissue from healthy tissue and facilitating restorative processes. Monocytes infiltrate the injury site to produce chemokines that recruit astrocytes which successively extend their processes towards monocytes during the recovery phase. In this fashion, monocytes infiltration serves to help repair the injured brain. Neurons and astrocytes also moderate brain inflammation via downregulation of cytotoxic inflammation. Depending on the severity of the brain injury, T and B cells can also be recruited to the brain pathology sites at later time points.
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65
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Zhan Z, Wu Y, Liu Z, Quan Y, Li D, Huang Y, Yang S, Wu K, Huang L, Yu M. Reduced Dendritic Spines in the Visual Cortex Contralateral to the Optic Nerve Crush Eye in Adult Mice. Invest Ophthalmol Vis Sci 2020; 61:55. [PMID: 32866269 PMCID: PMC7463183 DOI: 10.1167/iovs.61.10.55] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 07/31/2020] [Indexed: 01/19/2023] Open
Abstract
Purpose To determine alteration of dendritic spines and associated changes in the primary visual cortex (V1 region) related to unilateral optic nerve crush (ONC) in adult mice. Methods Adult unilateral ONC mice were established. Retinal nerve fiber layer (RNFL) thickness was measured by spectral-domain optical coherence tomography. Visual function was estimated by flash visual evoked potentials (FVEPs). Dendritic spines were observed in the V1 region contralateral to the ONC eye by two-photon imaging in vivo. The neurons, reactive astrocytes, oligodendrocytes, and activated microglia were assessed by NeuN, glial fibrillary acidic protein, CNPase, and CD68 in immunohistochemistry, respectively. Tropomyosin receptor kinase B (TrkB) and the markers in TrkB trafficking were estimated using western blotting and co-immunoprecipitation. Transmission electron microscopy and western blotting were used to evaluate autophagy. Results The amplitude and latency of FVEPs were decreased and delayed at 3 days, 1 week, 2 weeks, and 4 weeks after ONC, and RNFL thickness was decreased at 2 and 4 weeks after ONC. Dendritic spines were reduced in the V1 region contralateral to the ONC eye at 2, 3, and 4 weeks after ONC, with an unchanged number of neurons. Reactive astrocyte staining was increased at 2 and 4 weeks after ONC, but oligodendrocyte and activated microglia staining remained unchanged. TrkB was reduced with changes in the major trafficking proteins, and enhanced autophagy was observed in the V1 region contralateral to the ONC eye. Conclusions Dendritic spines were reduced in the V1 region contralateral to the ONC eye in adult mice. Reactive astrocytes and decreased TrkB may be associated with the reduced dendritic spines.
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Affiliation(s)
- Zongyi Zhan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yali Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Zitian Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yadan Quan
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Deling Li
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yiru Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Shana Yang
- Department of Physiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Kaili Wu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Lianyan Huang
- Department of Pathophysiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Minbin Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China
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