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Planas AM. Role of microglia in stroke. Glia 2024; 72:1016-1053. [PMID: 38173414 DOI: 10.1002/glia.24501] [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: 08/29/2023] [Revised: 12/07/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024]
Abstract
Microglia play key roles in the post-ischemic inflammatory response and damaged tissue removal reacting rapidly to the disturbances caused by ischemia and working to restore the lost homeostasis. However, the modified environment, encompassing ionic imbalances, disruption of crucial neuron-microglia interactions, spreading depolarization, and generation of danger signals from necrotic neurons, induce morphological and phenotypic shifts in microglia. This leads them to adopt a proinflammatory profile and heighten their phagocytic activity. From day three post-ischemia, macrophages infiltrate the necrotic core while microglia amass at the periphery. Further, inflammation prompts a metabolic shift favoring glycolysis, the pentose-phosphate shunt, and lipid synthesis. These shifts, combined with phagocytic lipid intake, drive lipid droplet biogenesis, fuel anabolism, and enable microglia proliferation. Proliferating microglia release trophic factors contributing to protection and repair. However, some microglia accumulate lipids persistently and transform into dysfunctional and potentially harmful foam cells. Studies also showed microglia that either display impaired apoptotic cell clearance, or eliminate synapses, viable neurons, or endothelial cells. Yet, it will be essential to elucidate the viability of engulfed cells, the features of the local environment, the extent of tissue damage, and the temporal sequence. Ischemia provides a rich variety of region- and injury-dependent stimuli for microglia, evolving with time and generating distinct microglia phenotypes including those exhibiting proinflammatory or dysfunctional traits and others showing pro-repair features. Accurate profiling of microglia phenotypes, alongside with a more precise understanding of the associated post-ischemic tissue conditions, is a necessary step to serve as the potential foundation for focused interventions in human stroke.
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Affiliation(s)
- Anna M Planas
- Cerebrovascular Research Laboratory, Department of Neuroscience and Experimental Therapeutics, Instituto de Investigaciones Biomédicas de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
- Cerebrovascular Diseases, Area of Clinical and Experimental Neuroscience, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS)-Hospital Clínic, Barcelona, Spain
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2
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Di Martino E, Rayasam A, Vexler ZS. Brain Maturation as a Fundamental Factor in Immune-Neurovascular Interactions in Stroke. Transl Stroke Res 2024; 15:69-86. [PMID: 36705821 PMCID: PMC10796425 DOI: 10.1007/s12975-022-01111-7] [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: 07/13/2022] [Revised: 11/24/2022] [Accepted: 11/25/2022] [Indexed: 01/28/2023]
Abstract
Injuries in the developing brain cause significant long-term neurological deficits. Emerging clinical and preclinical data have demonstrated that the pathophysiology of neonatal and childhood stroke share similar mechanisms that regulate brain damage, but also have distinct molecular signatures and cellular pathways. The focus of this review is on two different diseases-neonatal and childhood stroke-with emphasis on similarities and distinctions identified thus far in rodent models of these diseases. This includes the susceptibility of distinct cell types to brain injury with particular emphasis on the role of resident and peripheral immune populations in modulating stroke outcome. Furthermore, we discuss some of the most recent and relevant findings in relation to the immune-neurovascular crosstalk and how the influence of inflammatory mediators is dependent on specific brain maturation stages. Finally, we comment on the current state of treatments geared toward inducing neuroprotection and promoting brain repair after injury and highlight that future prophylactic and therapeutic strategies for stroke should be age-specific and consider gender differences in order to achieve optimal translational success.
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Affiliation(s)
- Elena Di Martino
- Department of Neurology, University California San Francisco, 675 Nelson Rising Lane, San Francisco, CA, 94158-0663, USA
| | - Aditya Rayasam
- Department of Neurology, University California San Francisco, 675 Nelson Rising Lane, San Francisco, CA, 94158-0663, USA
| | - Zinaida S Vexler
- Department of Neurology, University California San Francisco, 675 Nelson Rising Lane, San Francisco, CA, 94158-0663, USA.
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Dell’Orco M, Weisend JE, Perrone-Bizzozero NI, Carlson AP, Morton RA, Linsenbardt DN, Shuttleworth CW. Repetitive spreading depolarization induces gene expression changes related to synaptic plasticity and neuroprotective pathways. Front Cell Neurosci 2023; 17:1292661. [PMID: 38162001 PMCID: PMC10757627 DOI: 10.3389/fncel.2023.1292661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Accepted: 11/17/2023] [Indexed: 01/03/2024] Open
Abstract
Spreading depolarization (SD) is a slowly propagating wave of profound depolarization that sweeps through cortical tissue. While much emphasis has been placed on the damaging consequences of SD, there is uncertainty surrounding the potential activation of beneficial pathways such as cell survival and plasticity. The present study used unbiased assessments of gene expression to evaluate that compensatory and repair mechanisms could be recruited following SD, regardless of the induction method, which prior to this work had not been assessed. We also tested assumptions of appropriate controls and the spatial extent of expression changes that are important for in vivo SD models. SD clusters were induced with either KCl focal application or optogenetic stimulation in healthy mice. Cortical RNA was extracted and sequenced to identify differentially expressed genes (DEGs). SDs using both induction methods significantly upregulated 16 genes (vs. sham animals) that included the cell proliferation-related genes FOS, JUN, and DUSP6, the plasticity-related genes ARC and HOMER1, and the inflammation-related genes PTGS2, EGR2, and NR4A1. The contralateral hemisphere is commonly used as control tissue for DEG studies, but its activity could be modified by near-global disruption of activity in the adjacent brain. We found 21 upregulated genes when comparing SD-involved cortex vs. tissue from the contralateral hemisphere of the same animals. Interestingly, there was almost complete overlap (21/16) with the DEGs identified using sham controls. Neuronal activity also differs in SD initiation zones, where sustained global depolarization is required to initiate propagating events. We found that gene expression varied as a function of the distance from the SD initiation site, with greater expression differences observed in regions further away. Functional and pathway enrichment analyses identified axonogenesis, branching, neuritogenesis, and dendritic growth as significantly enriched in overlapping DEGs. Increased expression of SD-induced genes was also associated with predicted inhibition of pathways associated with cell death, and apoptosis. These results identify novel biological pathways that could be involved in plasticity and/or circuit modification in brain tissue impacted by SD. These results also identify novel functional targets that could be tested to determine potential roles in the recovery and survival of peri-infarct tissues.
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Affiliation(s)
- Michela Dell’Orco
- Department of Neurosciences, The University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Jordan E. Weisend
- Department of Neurosciences, The University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Nora I. Perrone-Bizzozero
- Department of Neurosciences, The University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Andrew P. Carlson
- Department of Neurosurgery, The University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - Russell A. Morton
- Department of Neurosciences, The University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - David N. Linsenbardt
- Department of Neurosciences, The University of New Mexico School of Medicine, Albuquerque, NM, United States
| | - C. William Shuttleworth
- Department of Neurosciences, The University of New Mexico School of Medicine, Albuquerque, NM, United States
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4
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Xie Z, Meng J, Wu Z, Nakanishi H, Hayashi Y, Kong W, Lan F, Narengaowa, Yang Q, Qing H, Ni J. The Dual Nature of Microglia in Alzheimer's Disease: A Microglia-Neuron Crosstalk Perspective. Neuroscientist 2023; 29:616-638. [PMID: 35348415 DOI: 10.1177/10738584211070273] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Microglia are critical players in the neuroimmune system, and their involvement in Alzheimer's disease (AD) pathogenesis is increasingly being recognized. However, whether microglia play a positive or negative role in AD remains largely controversial and the precise molecular targets for intervention are not well defined. This partly results from the opposing roles of microglia in AD pathology, and is mainly reflected in the microglia-neuron interaction. Microglia can prune synapses resulting in excessive synapse loss and neuronal dysfunction, but they can also promote synapse formation, enhancing neural network plasticity. Neuroimmune crosstalk accelerates microglial activation, which induces neuron death and enhances the microglial phagocytosis of β-amyloid to protect neurons. Moreover, microglia have dual opposing roles in developing the major pathological features in AD, such as amyloid deposition and blood-brain barrier permeability. This review summarizes the dual opposing role of microglia in AD from the perspective of the interaction between neurons and microglia. Additionally, current AD treatments targeting microglia and the advantages and disadvantages of developing microglia-targeted therapeutic strategies are discussed.
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Affiliation(s)
- Zhen Xie
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Department of Biology, Beijing Institute of Technology, Beijing, China
- Research Center for Resource Peptide Drugs, Shanxi Engineering & Technological Research Center for Conversation & Utilization of Regional Biological Resources, Yanan University, Yanan, China
| | - Jie Meng
- Department of Neurology and State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, and Collaborative Innovation Center for Biotherapy, Chengdu, China
| | - Zhou Wu
- Department of Aging Science and Pharmacology, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
- OBT Research Center, Faculty of Dental Science, Kyushu University, Fukuoka, Japan
| | - Hiroshi Nakanishi
- Department of Pharmacology, Faculty of Pharmacy, Yasuda Women's University, Hiroshima, Japan
| | - Yoshinori Hayashi
- Department of Physiology, Nihon University School of Dentistry, Tokyo, Japan
| | - Wei Kong
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Department of Biology, Beijing Institute of Technology, Beijing, China
| | - Fei Lan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Department of Biology, Beijing Institute of Technology, Beijing, China
| | - Narengaowa
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Department of Biology, Beijing Institute of Technology, Beijing, China
| | - Qinghu Yang
- Research Center for Resource Peptide Drugs, Shanxi Engineering & Technological Research Center for Conversation & Utilization of Regional Biological Resources, Yanan University, Yanan, China
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Department of Biology, Beijing Institute of Technology, Beijing, China
| | - Junjun Ni
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Department of Biology, Beijing Institute of Technology, Beijing, China
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Tang Y, Ji S, Li H, Dong B, Li Y, Zhu C, Chen L. Association of patent foramen ovale with epilepsy: A hospital-based case-control study. Epilepsia Open 2023; 8:1075-1083. [PMID: 37422851 PMCID: PMC10472407 DOI: 10.1002/epi4.12787] [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: 04/24/2023] [Accepted: 07/01/2023] [Indexed: 07/11/2023] Open
Abstract
OBJECTIVE This study aimed to investigate the proportion of patent foramen ovale (PFO) in people with epilepsy (PWE) compared to controls without epilepsy and to assess whether PWEs with and without PFO exhibit distinctive clinical features. METHODS This is a case-control study conducted in a hospital. Contrast transthoracic echocardiography with a venous microbubble bolus and provocative maneuvers (Valsalva and coughing) were used to identify PFO and its right-to-left shunt (RLS) among 741 PWEs and 800 controls without epilepsy. The risk of having PFO in PWEs was explored using multiple matching methods and logistic regression with adjusted congenital factors that may affect the occurrence of PFO. RESULTS The proportion of PFO in PWEs and controls was 39.00% and 24.25%, respectively. After 1:1 propensity score matching, the risk of suffering PFO in PWEs was 1.71 times (OR, 1.71; 95% CI, 1.24-2.36) higher than that in controls. PWEs also had a higher risk of having a high RLS grade (βepilepsy = 0.390, P < 0.001). Among clinical characteristics of PWEs, migraine, and drug-resistant epilepsy showed significantly different distributions between those without RLS and those with RLS grade I to III. PWEs with PFO had higher risk of suffering from migraine and drug-resistant epilepsy (OR in migraine, 2.54, 95% CI, 1.65-3.95; OR in drug-resistant epilepsy, 1.47, 95% CI, 1.06-2.03). SIGNIFICANCE The proportion of PFO was found to be higher in PWE than in controls without epilepsy, especially in patients with drug-resistant epilepsy, suggesting potential relationship between the two disorders. Large multicentric study will be needed to confirm this finding.
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Affiliation(s)
- Yusha Tang
- Department of NeurologySichuan University West China HospitalChengduChina
| | - Shuming Ji
- Department of Project Design and StatisticsSichuan University West China HospitalChengduChina
| | - Hua Li
- Department of NeurologySichuan University West China HospitalChengduChina
| | - Bosi Dong
- Department of NeurologySichuan University West China HospitalChengduChina
| | - Yajiao Li
- Department of Cardiology, West China HospitalSichuan UniversityChengduChina
| | - Chenxing Zhu
- Department of Clinical Research ManagementSichuan University West China HospitalChengduChina
| | - Lei Chen
- Department of NeurologySichuan University West China HospitalChengduChina
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6
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Nash C, Powell K, Lynch DG, Hartings JA, Li C. Nonpharmacological modulation of cortical spreading depolarization. Life Sci 2023:121833. [PMID: 37302793 DOI: 10.1016/j.lfs.2023.121833] [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: 04/21/2023] [Revised: 06/01/2023] [Accepted: 06/03/2023] [Indexed: 06/13/2023]
Abstract
AIMS Cortical spreading depolarization (CSD) is a wave of pathologic neuronal dysfunction that spreads through cerebral gray matter, causing neurologic disturbance in migraine and promoting lesion development in acute brain injury. Pharmacologic interventions have been found to be effective in migraine with aura, but their efficacy in acutely injured brains may be limited. This necessitates the assessment of possible adjunctive treatments, such as nonpharmacologic methods. This review aims to summarize currently available nonpharmacological techniques for modulating CSDs, present their mechanisms of action, and provide insight and future directions for CSD treatment. MAIN METHODS A systematic literature review was performed, generating 22 articles across 3 decades. Relevant data is broken down according to method of treatment. KEY FINDINGS Both pharmacologic and nonpharmacologic interventions can mitigate the pathological impact of CSDs via shared molecular mechanisms, including modulating K+/Ca2+/Na+/Cl- ion channels and NMDA, GABAA, serotonin, and CGRP ligand-based receptors and decreasing microglial activation. Preclinical evidence suggests that nonpharmacologic interventions, including neuromodulation, physical exercise, therapeutic hypothermia, and lifestyle changes can also target unique mechanisms, such as increasing adrenergic tone and myelination and modulating membrane fluidity, which may lend broader modulatory effects. Collectively, these mechanisms increase the electrical initiation threshold, increase CSD latency, slow CSD velocity, and decrease CSD amplitude and duration. SIGNIFICANCE Given the harmful consequences of CSDs, limitations of current pharmacological interventions to inhibit CSDs in acutely injured brains, and translational potentials of nonpharmacologic interventions to modulate CSDs, further assessment of nonpharmacologic modalities and their mechanisms to mitigate CSD-related neurologic dysfunction is warranted.
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Affiliation(s)
- Christine Nash
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA; Barnard College, New York, NY, USA
| | - Keren Powell
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Daniel G Lynch
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA; Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
| | - Jed A Hartings
- Department of Neurosurgery, University of Cincinnati, Cincinnati, OH, USA
| | - Chunyan Li
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA; Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA; Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA.
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7
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Sun Y, Che J, Zhang J. Emerging non-proinflammatory roles of microglia in healthy and diseased brains. Brain Res Bull 2023; 199:110664. [PMID: 37192719 DOI: 10.1016/j.brainresbull.2023.110664] [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: 07/14/2022] [Revised: 04/04/2023] [Accepted: 05/13/2023] [Indexed: 05/18/2023]
Abstract
Microglia, the resident myeloid cells of the central nervous system, are the first line of defense against foreign pathogens, thereby confining the extent of brain injury. However, the role of microglia is not limited to macrophage-like functions. In addition to proinflammatory response mediation, microglia are involved in neurodevelopmental remodeling and homeostatic maintenance in the absence of disease. An increasing number of studies have also elucidated microglia-mediated regulation of tumor growth and neural repair in diseased brains. Here, we review the non-proinflammatory roles of microglia, with the aim of promoting a deeper understanding of the functions of microglia in healthy and diseased brains and contributing to the development of novel therapeutics that target microglia in neurological disorders.
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Affiliation(s)
- Yinying Sun
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, 200032, Shanghai China.
| | - Ji Che
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, 200032, Shanghai China.
| | - Jun Zhang
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, 200032, Shanghai China; Department of Oncology, Shanghai Medical College, Fudan University, 200032, Shanghai China.
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8
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Ming LG, Hu DX, Zuo C, Zhang WJ. G protein-coupled P2Y12 receptor is involved in the progression of neuropathic pain. Biomed Pharmacother 2023; 162:114713. [PMID: 37084563 DOI: 10.1016/j.biopha.2023.114713] [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: 03/24/2023] [Revised: 04/13/2023] [Accepted: 04/14/2023] [Indexed: 04/23/2023] Open
Abstract
The pathological mechanism of neuropathic pain is complex, which seriously affects the physical and mental health of patients, and its treatment is also difficult. The role of G protein-coupled P2Y12 receptor in pain has been widely recognized and affirmed. After nerve injury, stimulated cells can release large amounts of nucleotides into the extracellular matrix, act on P2Y12 receptor. Activated P2Y12 receptor activates intracellular signal transduction and is involved in the development of pain. P2Y12 receptor activation can sensitize primary sensory neurons and receive sensory information. By transmitting the integrated information through the dorsal root of the spinal cord to the secondary neurons of the posterior horn of the spinal cord. The integrated information is then transmitted to the higher center through the ascending conduction tract to produce pain. Moreover, activation of P2Y12 receptor can mediate immune cells to release pro-inflammatory factors, increase damage to nerve cells, and aggravate pain. While inhibits the activation of P2Y12 receptor can effectively relieve pain. Therefore, in this article, we described P2Y12 receptor antagonists and their pharmacological properties. In addition, we explored the potential link between P2Y12 receptor and the nervous system, discussed the intrinsic link of P2Y12 receptor and neuropathic pain and as a potential pharmacological target for pain suppression.
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Affiliation(s)
- Li-Guo Ming
- Department of Gastrointestinal surgery, the Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi Province 343000, China
| | - Dong-Xia Hu
- Department of Rehabilitation Medicine, the Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi Province 343000, China
| | - Cheng Zuo
- Department of Gastrointestinal surgery, the Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi Province 343000, China
| | - Wen-Jun Zhang
- Department of Rehabilitation Medicine, the Second Affiliated Hospital, Nanchang University, Nanchang City, Jiangxi Province 343000, China.
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9
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Wiese BM, Alvarez Reyes A, Vanderah TW, Largent-Milnes TM. The endocannabinoid system and breathing. Front Neurosci 2023; 17:1126004. [PMID: 37144090 PMCID: PMC10153446 DOI: 10.3389/fnins.2023.1126004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Accepted: 03/16/2023] [Indexed: 05/06/2023] Open
Abstract
Recent changes in cannabis accessibility have provided adjunct therapies for patients across numerous disease states and highlights the urgency in understanding how cannabinoids and the endocannabinoid (EC) system interact with other physiological structures. The EC system plays a critical and modulatory role in respiratory homeostasis and pulmonary functionality. Respiratory control begins in the brainstem without peripheral input, and coordinates the preBötzinger complex, a component of the ventral respiratory group that interacts with the dorsal respiratory group to synchronize burstlet activity and drive inspiration. An additional rhythm generator: the retrotrapezoid nucleus/parafacial respiratory group drives active expiration during conditions of exercise or high CO2. Combined with the feedback information from the periphery: through chemo- and baroreceptors including the carotid bodies, the cranial nerves, stretch of the diaphragm and intercostal muscles, lung tissue, and immune cells, and the cranial nerves, our respiratory system can fine tune motor outputs that ensure we have the oxygen necessary to survive and can expel the CO2 waste we produce, and every aspect of this process can be influenced by the EC system. The expansion in cannabis access and potential therapeutic benefits, it is essential that investigations continue to uncover the underpinnings and mechanistic workings of the EC system. It is imperative to understand the impact cannabis, and exogenous cannabinoids have on these physiological systems, and how some of these compounds can mitigate respiratory depression when combined with opioids or other medicinal therapies. This review highlights the respiratory system from the perspective of central versus peripheral respiratory functionality and how these behaviors can be influenced by the EC system. This review will summarize the literature available on organic and synthetic cannabinoids in breathing and how that has shaped our understanding of the role of the EC system in respiratory homeostasis. Finally, we look at some potential future therapeutic applications the EC system has to offer for the treatment of respiratory diseases and a possible role in expanding the safety profile of opioid therapies while preventing future opioid overdose fatalities that result from respiratory arrest or persistent apnea.
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Affiliation(s)
- Beth M. Wiese
- Department of Pharmacology, University of Arizona, Tucson, AZ, United States
| | - Angelica Alvarez Reyes
- Department of Pharmacology, University of Arizona, Tucson, AZ, United States
- College of Medicine, University of Arizona, Tucson, AZ, United States
| | - Todd W. Vanderah
- Department of Pharmacology, University of Arizona, Tucson, AZ, United States
| | - Tally M. Largent-Milnes
- Department of Pharmacology, University of Arizona, Tucson, AZ, United States
- *Correspondence: Tally M. Largent-Milnes,
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10
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Xu Y, Fan Q. Relationship between chronic hypoxia and seizure susceptibility. CNS Neurosci Ther 2022; 28:1689-1705. [PMID: 35983626 PMCID: PMC9532927 DOI: 10.1111/cns.13942] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2021] [Revised: 07/26/2022] [Accepted: 07/27/2022] [Indexed: 01/16/2023] Open
Abstract
Chronic hypobaric hypoxia in high‐altitude areas is closely related to the occurrence of many neurological diseases. Among these diseases, epilepsy is a common disease of the nervous system that is difficult to diagnose and treat, with a long treatment cycle. As of 2019, there were more than 70 million epilepsy patients worldwide, including 10 million in China. Studies have shown that chronic hypoxia promotes the occurrence and development of epilepsy, and elucidation of the relationship between chronic hypoxia and epilepsy is important for studying the pathogenesis of epilepsy and exploring the potential characteristics of epilepsy and new drug targets for epilepsy. In this article, we review the factors that may cause increased seizure susceptibility in chronic hypoxia and consider the potential relationship between chronic hypobaric hypoxia and seizure susceptibility in high‐altitude areas and prospects surrounding related research in the future.
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Affiliation(s)
- YuanHang Xu
- Qinghai University Graduate School, Xining, China.,Department of Neurology, Qinghai Provincial People's Hospital Xining, Xining, China
| | - QingLi Fan
- Department of Neurology, Qinghai Provincial People's Hospital Xining, Xining, China
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11
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Kiss T, Nyúl-Tóth Á, DelFavero J, Balasubramanian P, Tarantini S, Faakye J, Gulej R, Ahire C, Ungvari A, Yabluchanskiy A, Wiley G, Garman L, Ungvari Z, Csiszar A. Spatial transcriptomic analysis reveals inflammatory foci defined by senescent cells in the white matter, hippocampi and cortical grey matter in the aged mouse brain. GeroScience 2022; 44:661-681. [PMID: 35098444 PMCID: PMC9135953 DOI: 10.1007/s11357-022-00521-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 01/19/2022] [Indexed: 12/11/2022] Open
Abstract
There is strong evidence that aging is associated with an increased presence of senescent cells in the brain. The finding that treatment with senolytic drugs improves cognitive performance of aged laboratory mice suggests that increased cellular senescence is causally linked to age-related cognitive decline. The relationship between senescent cells and their relative locations within the brain is critical to understanding the pathology of age-related cognitive decline and dementia. To assess spatial distribution of cellular senescence in the aged mouse brain, spatially resolved whole transcriptome mRNA expression was analyzed in sections of brains derived from young (3 months old) and aged (28 months old) C57BL/6 mice while capturing histological information in the same tissue section. Using this spatial transcriptomics (ST)-based method, microdomains containing senescent cells were identified on the basis of their senescence-related gene expression profiles (i.e., expression of the senescence marker cyclin-dependent kinase inhibitor p16INK4A encoded by the Cdkn2a gene) and were mapped to different anatomical brain regions. We confirmed that brain aging is associated with increased cellular senescence in the white matter, the hippocampi and the cortical grey matter. Transcriptional analysis of the senescent cell-containing ST spots shows that presence of senescent cells is associated with a gene expression signature suggestive of neuroinflammation. GO enrichment analysis of differentially expressed genes in the outer region of senescent cell-containing ST spots ("neighboring ST spots") also identified functions related to microglia activation and neuroinflammation. In conclusion, senescent cells accumulate with age in the white matter, the hippocampi and cortical grey matter and likely contribute to the genesis of inflammatory foci in a paracrine manner.
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Affiliation(s)
- Tamas Kiss
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA.
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary.
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Translational Medicine, Semmelweis University, Budapest, Hungary.
- First Department of Pediatrics, Semmelweis University, HU, 1083, Budapest, Hungary.
| | - Ádám Nyúl-Tóth
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Eötvös Loránd Research Network (ELKH), Szeged, Hungary
| | - Jordan DelFavero
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA
| | - Priya Balasubramanian
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA
| | - Stefano Tarantini
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Janet Faakye
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA
| | - Rafal Gulej
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA
| | - Chetan Ahire
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA
| | - Anna Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA
| | - Andriy Yabluchanskiy
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
| | - Graham Wiley
- Oklahoma Medical Research Foundation, Genes & Human Disease Research Program, Oklahoma City, OK, USA
| | - Lori Garman
- Oklahoma Medical Research Foundation, Genes & Human Disease Research Program, Oklahoma City, OK, USA
| | - Zoltan Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA.
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary.
- Department of Health Promotion Sciences, College of Public Health, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA.
| | - Anna Csiszar
- Vascular Cognitive Impairment and Neurodegeneration Program, Oklahoma Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 975 NE 10th Street, Oklahoma City, OK, 73104, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Translational Medicine, Semmelweis University, Budapest, Hungary
- The Peggy and Charles Stephenson Cancer Center, University of Oklahoma Health Sciences Center, Oklahoma City, OK, 73104, USA
- Theoretical Medicine Doctoral School, International Training Program in Geroscience, University of Szeged, Szeged, Hungary
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12
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Microglia Modulate Cortical Spreading Depolarizations After Ischemic Stroke: A Narrative Review. Neurocrit Care 2022; 37:133-138. [PMID: 35288861 PMCID: PMC9259539 DOI: 10.1007/s12028-022-01469-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 02/08/2022] [Indexed: 01/06/2023]
Abstract
Cortical spreading depolarizations (CSDs) are characterized by waves of diminished electroencephalography activity that propagate across the cortex with subsequent loss of ionic homeostasis. CSDs have been found in many pathological conditions, including migraine, traumatic brain injury, and ischemic stroke. Because of CSD-associated ionic and metabolic disturbances at the peri-infarct area after ischemic stroke, it is thought that CSDs exacerbate tissue infarction and worsen clinical outcomes. Microglia, the main innate immune cells in the brain, are among the first responders to brain tissue damage. Recent studies demonstrated that microglia play a critical role in CSD initiation and propagation. In this article, we discuss the significance of CSD in the setting of ischemic stroke and how microglia may modulate peri-infarct CSDs, also known as iso-electric depolarizations. Finally, we discuss the significance of microglial Ca2+ and how it might be used as a potential therapeutic target for patients with ischemic stroke.
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13
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Lu YL, Scharfman HE. New Insights and Methods for Recording and Imaging Spontaneous Spreading Depolarizations and Seizure-Like Events in Mouse Hippocampal Slices. Front Cell Neurosci 2021; 15:761423. [PMID: 34899190 PMCID: PMC8663723 DOI: 10.3389/fncel.2021.761423] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2021] [Accepted: 10/04/2021] [Indexed: 11/30/2022] Open
Abstract
Spreading depolarization (SD) is a sudden, large, and synchronous depolarization of principal cells which also involves interneurons and astrocytes. It is followed by depression of neuronal activity, and it slowly propagates across brain regions like cortex or hippocampus. SD is considered to be mechanistically relevant to migraine, epilepsy, and traumatic brain injury (TBI), but there are many questions about its basic neurophysiology and spread. Research into SD in hippocampus using slices is often used to gain insight and SD is usually triggered by a focal stimulus with or without an altered extracellular buffer. Here, we optimize an in vitro experimental model allowing us to record SD without focal stimulation, which we call spontaneous. This method uses only an altered extracellular buffer containing 0 mM Mg2+ and 5 mM K+ and makes it possible for simultaneous patch and extracellular recording in a submerged chamber plus intrinsic optical imaging in slices of either sex. We also add methods for quantification and show the quantified optical signal is much more complex than imaging alone would suggest. In brief, acute hippocampal slices were prepared with a chamber holding a submerged slice but with flow of artificial cerebrospinal fluid (aCSF) above and below, which we call interface-like. As soon as slices were placed in the chamber, aCSF with 0 Mg2+/5 K+ was used. Most mouse slices developed SD and did so in the first hour of 0 Mg2+/5 K+ aCSF exposure. In addition, prolonged bursts we call seizure-like events (SLEs) occurred, and the interactions between SD and SLEs suggest potentially important relationships. Differences between rats and mice in different chambers are described. Regarding optical imaging, SD originated in CA3 and the pattern of spread to CA1 and the dentate gyrus was similar in some ways to prior studies but also showed interesting differences. In summary, the methods are easy to use, provide new opportunities to study SD, new insights, and are inexpensive. They support previous suggestions that SD is diverse, and also suggest that participation by the dentate gyrus merits greater attention.
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Affiliation(s)
- Yi-Ling Lu
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States
| | - Helen E. Scharfman
- Center for Dementia Research, The Nathan Kline Institute for Psychiatric Research, Orangeburg, NY, United States
- Department of Child and Adolescent Psychiatry, New York University Langone Health, New York, NY, United States
- Department of Neuroscience and Physiology, New York University Langone Health, New York, NY, United States
- Department of Psychiatry, New York University Langone Health, New York, NY, United States
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14
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Rayasam A, Fukuzaki Y, Vexler ZS. Microglia-leucocyte axis in cerebral ischaemia and inflammation in the developing brain. Acta Physiol (Oxf) 2021; 233:e13674. [PMID: 33991400 DOI: 10.1111/apha.13674] [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] [Received: 09/30/2020] [Revised: 05/06/2021] [Accepted: 05/08/2021] [Indexed: 12/13/2022]
Abstract
Development of the Central Nervous System (CNS) is reliant on the proper function of numerous intricately orchestrated mechanisms that mature independently, including constant communication between the CNS and the peripheral immune system. This review summarizes experimental knowledge of how cerebral ischaemia in infants and children alters physiological communication between leucocytes, brain immune cells, microglia and the neurovascular unit (NVU)-the "microglia-leucocyte axis"-and contributes to acute and long-term brain injury. We outline physiological development of CNS barriers in relation to microglial and leucocyte maturation and the plethora of mechanisms by which microglia and peripheral leucocytes communicate during postnatal period, including receptor-mediated and intracellular inflammatory signalling, lipids, soluble factors and extracellular vesicles. We focus on the "microglia-leucocyte axis" in rodent models of most common ischaemic brain diseases in the at-term infants, hypoxic-ischaemic encephalopathy (HIE) and focal arterial stroke and discuss commonalities and distinctions of immune-neurovascular mechanisms in neonatal and childhood stroke compared to stroke in adults. Given that hypoxic and ischaemic brain damage involve Toll-like receptor (TLR) activation, we discuss the modulatory role of viral and bacterial TLR2/3/4-mediated infection in HIE, perinatal and childhood stroke. Furthermore, we provide perspective of the dynamics and contribution of the axis in cerebral ischaemia depending on the CNS maturational stage at the time of insult, and modulation independently and in consort by individual axis components and in a sex dependent ways. Improved understanding on how to modify crosstalk between microglia and leucocytes will aid in developing age-appropriate therapies for infants and children who suffered cerebral ischaemia.
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Affiliation(s)
- Aditya Rayasam
- Department of Neurology University of California San Francisco San Francisco CA USA
| | - Yumi Fukuzaki
- Department of Neurology University of California San Francisco San Francisco CA USA
| | - Zinaida S. Vexler
- Department of Neurology University of California San Francisco San Francisco CA USA
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15
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Epigenetics and Communication Mechanisms in Microglia Activation with a View on Technological Approaches. Biomolecules 2021; 11:biom11020306. [PMID: 33670563 PMCID: PMC7923060 DOI: 10.3390/biom11020306] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 02/12/2021] [Accepted: 02/14/2021] [Indexed: 12/13/2022] Open
Abstract
Microglial cells, the immune cells of the central nervous system (CNS), play a crucial role for the proper brain development and function and in CNS homeostasis. While in physiological conditions, microglia continuously check the state of brain parenchyma, in pathological conditions, microglia can show different activated phenotypes: In the early phases, microglia acquire the M2 phenotype, increasing phagocytosis and releasing neurotrophic and neuroprotective factors. In advanced phases, they acquire the M1 phenotype, becoming neurotoxic and contributing to neurodegeneration. Underlying this phenotypic change, there is a switch in the expression of specific microglial genes, in turn modulated by epigenetic changes, such as DNA methylation, histones post-translational modifications and activity of miRNAs. New roles are attributed to microglial cells, including specific communication with neurons, both through direct cell–cell contact and by release of many different molecules, either directly or indirectly, through extracellular vesicles. In this review, recent findings on the bidirectional interaction between neurons and microglia, in both physiological and pathological conditions, are highlighted, with a focus on the complex field of microglia immunomodulation through epigenetic mechanisms and/or released factors. In addition, advanced technologies used to study these mechanisms, such as microfluidic, 3D culture and in vivo imaging, are presented.
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16
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Lin SS, Tang Y, Illes P, Verkhratsky A. The Safeguarding Microglia: Central Role for P2Y 12 Receptors. Front Pharmacol 2021; 11:627760. [PMID: 33519493 PMCID: PMC7840491 DOI: 10.3389/fphar.2020.627760] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2020] [Accepted: 11/30/2020] [Indexed: 12/14/2022] Open
Affiliation(s)
- Si-Si Lin
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- International Collaborative Center on Big Science Plan for Purine Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Yong Tang
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- International Collaborative Center on Big Science Plan for Purine Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
| | - Peter Illes
- Acupuncture and Tuina School, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- International Collaborative Center on Big Science Plan for Purine Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Rudolf Boehm Institute for Pharmacology and Toxicology, University of Leipzig, Leipzig, Germany
| | - Alexei Verkhratsky
- International Collaborative Center on Big Science Plan for Purine Signalling, Chengdu University of Traditional Chinese Medicine, Chengdu, China
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, United Kingdom
- Achucarro Centre for Neuroscience, IKERBASQUE, Basque Foundation for Science, Bilbao, Spain
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17
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Cserép C, Pósfai B, Dénes Á. Shaping Neuronal Fate: Functional Heterogeneity of Direct Microglia-Neuron Interactions. Neuron 2020; 109:222-240. [PMID: 33271068 DOI: 10.1016/j.neuron.2020.11.007] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/13/2020] [Accepted: 11/06/2020] [Indexed: 12/11/2022]
Abstract
The functional contribution of microglia to normal brain development, healthy brain function, and neurological disorders is increasingly recognized. However, until recently, the nature of intercellular interactions mediating these effects remained largely unclear. Recent findings show microglia establishing direct contact with different compartments of neurons. Although communication between microglia and neurons involves intermediate cells and soluble factors, direct membrane contacts enable a more precisely regulated, dynamic, and highly effective form of interaction for fine-tuning neuronal responses and fate. Here, we summarize the known ultrastructural, molecular, and functional features of direct microglia-neuron interactions and their roles in brain disease.
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Affiliation(s)
- Csaba Cserép
- "Momentum" Laboratory of Neuroimmunology, Institute of Experimental Medicine, Szigony u. 43, 1083 Budapest, Hungary
| | - Balázs Pósfai
- "Momentum" Laboratory of Neuroimmunology, Institute of Experimental Medicine, Szigony u. 43, 1083 Budapest, Hungary; Szentágothai János Doctoral School of Neurosciences, Semmelweis University, Üllői út 26, 1085 Budapest, Hungary
| | - Ádám Dénes
- "Momentum" Laboratory of Neuroimmunology, Institute of Experimental Medicine, Szigony u. 43, 1083 Budapest, Hungary.
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18
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Affiliation(s)
- Midori A Yenari
- Department of Neurology, University of California, San Francisco, CA, USA.,Neurology Service, San Francisco Veterans Affairs Medical Center, San Francisco, CA, USA
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19
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Liu L, Kearns KN, Eli I, Sharifi KA, Soldozy S, Carlson EW, Scott KW, Sluzewski MF, Acton ST, Stauderman KA, Kalani MYS, Park M, Tvrdik P. Microglial Calcium Waves During the Hyperacute Phase of Ischemic Stroke. Stroke 2020; 52:274-283. [PMID: 33161850 DOI: 10.1161/strokeaha.120.032766] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
BACKGROUND AND PURPOSE Ischemic injury triggers multiple pathological responses in the brain tissue, including spreading depolarizations across the cerebral cortex (cortical spreading depolarizations [CSD]). Microglia have been recently shown to play a significant role in the propagation of CSD. However, the intracellular responses of myeloid cells during ischemic stroke have not been investigated. METHODS We have studied intracellular calcium activity in cortical microglia in the stroke model of the middle cerebral artery occlusion, using the murine Polr2a-based and Cre-dependent GCaMP5 and tdTomato reporter (PC::G5-tdT). High-speed 2-photon microscopy through cranial windows was employed to record signals from genetically encoded indicators of calcium. Inflammatory stimuli and pharmacological inhibition were used to modulate microglial calcium responses in the somatosensory cortex. RESULTS In vivo imaging revealed periodical calcium activity in microglia during the hyperacute phase of ischemic stroke. This activity was more frequent during the first 6 hours after occlusion, but the amplitudes of calcium transients became larger at later time points. Consistent with CSD nature of these events, we reproducibly triggered comparable calcium transients with microinjections of potassium chloride (KCl) into adjacent cortical areas. Furthermore, lipopolysaccharide-induced peripheral inflammation, mimicking sterile inflammation during ischemic stroke, produced significantly greater microglial calcium transients during CSD. Finally, in vivo pharmacological analysis with CRAC (calcium release-activated channel) inhibitor CM-EX-137 demonstrated that CSD-associated microglial calcium transients after KCl microinjections are mediated at least in part by the CRAC mechanism. CONCLUSIONS Our findings demonstrate that microglia participate in ischemic brain injury via previously undetected mechanisms, which may provide new avenues for therapeutic interventions.
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Affiliation(s)
- Lei Liu
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
| | - Kathryn N Kearns
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
| | - Ilyas Eli
- Department of Neurosurgery (I.E., E.W.C.), University of Utah School of Medicine, Salt Lake City
| | - Khadijeh A Sharifi
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
- Department of Neuroscience (K.A. Sharifi, M.Y.S.K., P.T.), University of Virginia Health System, Charlottesville
| | - Sauson Soldozy
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
| | - Elizabeth W Carlson
- Department of Neurosurgery (I.E., E.W.C.), University of Utah School of Medicine, Salt Lake City
| | - Kyle W Scott
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
| | - M Filip Sluzewski
- Department of Electrical and Computer Engineering (M.F.S., S.T.A.), University of Virginia Health System, Charlottesville
| | - Scott T Acton
- Department of Electrical and Computer Engineering (M.F.S., S.T.A.), University of Virginia Health System, Charlottesville
| | | | - M Yashar S Kalani
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
- Department of Neuroscience (K.A. Sharifi, M.Y.S.K., P.T.), University of Virginia Health System, Charlottesville
| | - Min Park
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
| | - Petr Tvrdik
- Department of Neurological Surgery (L.L., K.N.K., K.A. Sharifi, S.S., K.W.S., M.Y.S.K., M.P., P.T.), University of Virginia Health System, Charlottesville
- Department of Neuroscience (K.A. Sharifi, M.Y.S.K., P.T.), University of Virginia Health System, Charlottesville
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20
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Zhang Y, Li H, Li X, Wu J, Xue T, Wu J, Shen H, Li X, Shen M, Chen G. TMEM16F Aggravates Neuronal Loss by Mediating Microglial Phagocytosis of Neurons in a Rat Experimental Cerebral Ischemia and Reperfusion Model. Front Immunol 2020; 11:1144. [PMID: 32733436 PMCID: PMC7359929 DOI: 10.3389/fimmu.2020.01144] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2020] [Accepted: 05/11/2020] [Indexed: 12/20/2022] Open
Abstract
Cerebral ischemia is a severe, acute condition, normally caused by cerebrovascular disease, and results in high rates of disability, and death. Phagoptosis is a newly recognized form of cell death caused by phagocytosis of viable cells, and has been reported to contribute to neuronal loss in brain tissue after ischemic stroke. Previous data indicated that exposure of phosphatidylserine to viable neurons could induce microglial phagocytosis of such neurons. Phosphatidylserine can be reversibly exposed to viable cells as a result of a calcium-activated phospholipid scramblase named TMEM16F. TMEM16F-mediated phospholipid scrambling on platelet membranes is critical for hemostasis and thrombosis, which plays an important role in Scott syndrome and has been confirmed by much research. However, few studies have investigated the association between TMEM16F and phagocytosis in ischemic stroke. In this study, a middle-cerebral-artery occlusion/reperfusion (MCAO/R) model was used in adult male Sprague-Dawley rats in vivo, and cultured neurons were exposed to oxygen-glucose deprivation/reoxygenation (OGD/R) to simulate cerebral ischemia-reperfusion (I/R) injury in vitro. We found that the protein level of TMEM16F was significantly increased at 12 h after I-R injury both in vivo and in vitro, and reversible phosphatidylserine exposure was confirmed in neurons undergoing I/R injury in vitro. Additionally, we constructed a LV-TMEM16F-RNAi transfection system to suppress the expression of TMEM16F during and after cerebral ischemia. As a result, TMEM16F knockdown alleviated motor function injury and decreased the microglial phagocytosis of viable neurons in the penumbra through inhibiting the “eat-me” signal phosphatidylserine. Our data indicate that reducing neuronal phosphatidylserine-exposure via deficiency of TMEM16F blocks phagocytosis of neurons and rescues stressed-but-still-viable neurons in the penumbra, which may contribute to reducing infarct volume and improving functional recovering.
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Affiliation(s)
- Yijie Zhang
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Haiying Li
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xiang Li
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jie Wu
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Tao Xue
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Jiang Wu
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Haitao Shen
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Xiang Li
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Meifen Shen
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Gang Chen
- Brain and Nerve Research Laboratory, Department of Neurosurgery, The First Affiliated Hospital of Soochow University, Suzhou, China
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21
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Lewen A, Ta TT, Cesetti T, Hollnagel JO, Papageorgiou IE, Chausse B, Kann O. Neuronal gamma oscillations and activity-dependent potassium transients remain regular after depletion of microglia in postnatal cortex tissue. J Neurosci Res 2020; 98:1953-1967. [PMID: 32638411 DOI: 10.1002/jnr.24689] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/09/2020] [Accepted: 06/12/2020] [Indexed: 12/28/2022]
Abstract
Microglial cells (resident macrophages) feature rapid activation in CNS disease and can acquire multiple phenotypes exerting neuroprotection or neurotoxicity. The functional impact of surveying ("resting") microglia on neural excitability and neurotransmission in physiology is widely unknown, however. We addressed this issue in male rat hippocampal slice cultures (in situ) by pharmacological microglial ablation within days and by characterizing neuronal gamma-band oscillations (30-70 Hz) that are highly sensitive to neuromodulators and disturbances in ion and energy regulation. Gamma oscillations support action potential timing and synaptic plasticity, associate with higher brain functions like perception and memory, and require precise communication between excitatory pyramidal cells and inhibitory (GABAergic) interneurons. The slice cultures featured well-preserved hippocampal cytoarchitecture and parvalbumin-positive interneuron networks, microglia with ramified morphology, and low basal levels of IL-6, TNF-α, and nitric oxide (NO). Stimulation of slice cultures with the pro-inflammatory cytokine IFN-γ or bacterial LPS serving as positive controls for microglial reactivity induced MHC-II expression and increased cytokine and NO release. Chronic exposure of slice cultures to liposome-encapsulated clodronate reduced the microglial cell population by about 96%, whereas neuronal structures, astrocyte GFAP expression, and basal levels of cytokines and NO were unchanged. Notably, the properties of gamma oscillations reflecting frequency, number and synchronization of synapse activity were regular after microglial depletion. Also, electrical stimulus-induced transients of the extracellular potassium concentration ([K+ ]o ) reflecting cellular K+ efflux, clearance and buffering were unchanged. This suggests that nonreactive microglia are dispensable for neuronal homeostasis and neuromodulation underlying network signaling and rhythm generation in cortical tissue.
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Affiliation(s)
- Andrea Lewen
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Thuy-Truc Ta
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Tiziana Cesetti
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Jan-Oliver Hollnagel
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Ismini E Papageorgiou
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Bruno Chausse
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, Germany.,Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
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