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Piccioni G, Maisto N, d'Ettorre A, Strimpakos G, Nisticò R, Triaca V, Mango D. Switch to phagocytic microglia by CSFR1 inhibition drives amyloid-beta clearance from glutamatergic terminals rescuing LTP in acute hippocampal slices. Transl Psychiatry 2024; 14:338. [PMID: 39179543 PMCID: PMC11344079 DOI: 10.1038/s41398-024-03019-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Revised: 06/21/2024] [Accepted: 07/08/2024] [Indexed: 08/26/2024] Open
Abstract
Microglia, traditionally regarded as innate immune cells in the brain, drive neuroinflammation and synaptic dysfunctions in the early phases of Alzheimer disease (AD), acting upstream to Aβ accumulation. Colony stimulating factor 1-receptor (CSF-1R) is predominantly expressed on microglia and its levels are significantly increased in neurodegenerative diseases, possibly contributing to the chronic inflammatory microglial response. On the other hand, CSF-1R inhibitors confer neuroprotection in preclinical models of neurodegenerative diseases. Here, we determined the effects of the CSF-1R inhibitor PLX3397 on the Aβ-mediated synaptic alterations in ex vivo hippocampal slices. Electrophysiological findings show that PLX3397 rescues LTP impairment and neurotransmission changes induced by Aβ. In addition, using confocal imaging experiments, we demonstrate that PLX3397 stimulates a microglial transition toward a phagocytic phenotype, which in turn promotes the clearance of Aβ from glutamatergic terminals. We believe that the selective pruning of Aβ-loaded synaptic terminals might contribute to the restoration of LTP and excitatory transmission alterations observed upon acute PLX3397 treatment. This result is in accordance with the mechanism proposed for CSF1R inhibitors, that is to eliminate responsive microglia and replace it with newly generated, homeostatic microglia, capable of promoting brain repair. Overall, our findings identify a connection between the rapid microglia adjustments and the early synaptic alterations observed in AD, possibly highlighting a novel disease-modifying target.
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Affiliation(s)
- Gaia Piccioni
- Laboratory Pharmacology of Synaptic Plasticity, European Brain Research Institute, Rome, Italy
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, Rome, Italy
| | - Nunzia Maisto
- Laboratory Pharmacology of Synaptic Plasticity, European Brain Research Institute, Rome, Italy
- Department of Physiology and Pharmacology "V. Erspamer", Sapienza University of Rome, Rome, Italy
| | - Asia d'Ettorre
- Institute of Biochemistry and Cell Biology, National Research Council (CNR), International Campus A. Buzzati-Traverso, Rome, Italy
- School of Pharmacy, University of Rome "Tor Vergata", Rome, Italy
| | - Georgios Strimpakos
- Institute of Biochemistry and Cell Biology, National Research Council (CNR), International Campus A. Buzzati-Traverso, Rome, Italy
| | - Robert Nisticò
- Laboratory Pharmacology of Synaptic Plasticity, European Brain Research Institute, Rome, Italy.
- School of Pharmacy, University of Rome "Tor Vergata", Rome, Italy.
| | - Viviana Triaca
- Institute of Biochemistry and Cell Biology, National Research Council (CNR), International Campus A. Buzzati-Traverso, Rome, Italy.
| | - Dalila Mango
- Laboratory Pharmacology of Synaptic Plasticity, European Brain Research Institute, Rome, Italy.
- School of Pharmacy, University of Rome "Tor Vergata", Rome, Italy.
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2
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Islam R, Choudhary H, Rajan R, Vrionis F, Hanafy KA. An overview on microglial origin, distribution, and phenotype in Alzheimer's disease. J Cell Physiol 2024; 239:e30829. [PMID: 35822939 PMCID: PMC9837313 DOI: 10.1002/jcp.30829] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 06/12/2022] [Accepted: 07/04/2022] [Indexed: 01/17/2023]
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disease that is responsible for about one-third of dementia cases worldwide. It is believed that AD is initiated with the deposition of Ab plaques in the brain. Genetic studies have shown that a high number of AD risk genes are expressed by microglia, the resident macrophages of brain. Common mode of action by microglia cells is neuroinflammation and phagocytosis. Moreover, it has been discovered that inflammatory marker levels are increased in AD patients. Recent studies advocate that neuroinflammation plays a major role in AD progression. Microglia have different activation profiles depending on the region of brain and stimuli. In different activation, profile microglia can generate either pro-inflammatory or anti-inflammatory responses. Microglia defend brain cells from pathogens and respond to injuries; also, microglia can lead to neuronal death along the way. In this review, we will bring the different roles played by microglia and microglia-related genes in the progression of AD.
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Affiliation(s)
- Rezwanul Islam
- Department of Biomedical Sciences, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL
| | - Hadi Choudhary
- Department of Biomedical Sciences, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL
| | - Robin Rajan
- Marcus Neuroscience Institute, Boca Raton Medical Center, Boca Raton, FL
| | - Frank Vrionis
- Department of Biomedical Sciences, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL
- Marcus Neuroscience Institute, Boca Raton Medical Center, Boca Raton, FL
| | - Khalid A. Hanafy
- Department of Biomedical Sciences, Charles E. Schmidt College of Medicine, Florida Atlantic University, Boca Raton, FL
- Marcus Neuroscience Institute, Boca Raton Medical Center, Boca Raton, FL
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3
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Katchur NJ, Notterman DA. Recent insights from non-mammalian models of brain injuries: an emerging literature. Front Neurol 2024; 15:1378620. [PMID: 38566857 PMCID: PMC10985199 DOI: 10.3389/fneur.2024.1378620] [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: 01/29/2024] [Accepted: 02/26/2024] [Indexed: 04/04/2024] Open
Abstract
Traumatic brain injury (TBI) is a major global health concern and is increasingly recognized as a risk factor for neurodegenerative diseases including Alzheimer's disease (AD) and chronic traumatic encephalopathy (CTE). Repetitive TBIs (rTBIs), commonly observed in contact sports, military service, and intimate partner violence (IPV), pose a significant risk for long-term sequelae. To study the long-term consequences of TBI and rTBI, researchers have typically used mammalian models to recapitulate brain injury and neurodegenerative phenotypes. However, there are several limitations to these models, including: (1) lengthy observation periods, (2) high cost, (3) difficult genetic manipulations, and (4) ethical concerns regarding prolonged and repeated injury of a large number of mammals. Aquatic vertebrate model organisms, including Petromyzon marinus (sea lampreys), zebrafish (Danio rerio), and invertebrates, Caenorhabditis elegans (C. elegans), and Drosophila melanogaster (Drosophila), are emerging as valuable tools for investigating the mechanisms of rTBI and tauopathy. These non-mammalian models offer unique advantages, including genetic tractability, simpler nervous systems, cost-effectiveness, and quick discovery-based approaches and high-throughput screens for therapeutics, which facilitate the study of rTBI-induced neurodegeneration and tau-related pathology. Here, we explore the use of non-vertebrate and aquatic vertebrate models to study TBI and neurodegeneration. Drosophila, in particular, provides an opportunity to explore the longitudinal effects of mild rTBI and its impact on endogenous tau, thereby offering valuable insights into the complex interplay between rTBI, tauopathy, and neurodegeneration. These models provide a platform for mechanistic studies and therapeutic interventions, ultimately advancing our understanding of the long-term consequences associated with rTBI and potential avenues for intervention.
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Affiliation(s)
- Nicole J. Katchur
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States
- Rutgers-Robert Wood Johnson Medical School, Piscataway, NJ, United States
| | - Daniel A. Notterman
- Department of Molecular Biology, Princeton University, Princeton, NJ, United States
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4
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Weyer MP, Strehle J, Schäfer MKE, Tegeder I. Repurposing of pexidartinib for microglia depletion and renewal. Pharmacol Ther 2024; 253:108565. [PMID: 38052308 DOI: 10.1016/j.pharmthera.2023.108565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Revised: 11/20/2023] [Accepted: 11/22/2023] [Indexed: 12/07/2023]
Abstract
Pexidartinib (PLX3397) is a small molecule receptor tyrosine kinase inhibitor of colony stimulating factor 1 receptor (CSF1R) with moderate selectivity over other members of the platelet derived growth factor receptor family. It is approved for treatment of tenosynovial giant cell tumors (TGCT). CSF1R is highly expressed by microglia, which are macrophages of the central nervous system (CNS) that defend the CNS against injury and pathogens and contribute to synapse development and plasticity. Challenged by pathogens, apoptotic cells, debris, or inflammatory molecules they adopt a responsive state to propagate the inflammation and eventually return to a homeostatic state. The phenotypic switch may fail, and disease-associated microglia contribute to the pathophysiology in neurodegenerative or neuropsychiatric diseases or long-lasting detrimental brain inflammation after brain, spinal cord or nerve injury or ischemia/hemorrhage. Microglia also contribute to the growth permissive tumor microenvironment of glioblastoma (GBM). In rodents, continuous treatment for 1-2 weeks via pexidartinib food pellets leads to a depletion of microglia and subsequent repopulation from the remaining fraction, which is aided by peripheral monocytes that search empty niches for engraftment. The putative therapeutic benefit of such microglia depletion or forced renewal has been assessed in almost any rodent model of CNS disease or injury or GBM with heterogeneous outcomes, but a tendency of partial beneficial effects. So far, microglia monitoring e.g. via positron emission imaging is not standard of care for patients receiving Pexidartinib (e.g. for TGCT), so that the depletion and repopulation efficiency in humans is still largely unknown. Considering the virtuous functions of microglia, continuous depletion is likely no therapeutic option but short-lasting transient partial depletion to stimulate microglia renewal or replace microglia in genetic disease in combination with e.g. stem cell transplantation or as part of a multimodal concept in treatment of glioblastoma appears feasible. The present review provides an overview of the preclinical evidence pro and contra microglia depletion as a therapeutic approach.
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Affiliation(s)
- Marc-Philipp Weyer
- Institute of Clinical Pharmacology, Goethe-University Frankfurt, Faculty of Medicine, Frankfurt, Germany
| | - Jenny Strehle
- Department of Anesthesiology, University Medical Center Johannes Gutenberg-University Mainz, Germany
| | - Michael K E Schäfer
- Department of Anesthesiology, University Medical Center Johannes Gutenberg-University Mainz, Germany
| | - Irmgard Tegeder
- Institute of Clinical Pharmacology, Goethe-University Frankfurt, Faculty of Medicine, Frankfurt, Germany.
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Kim JD, Copperi F, Diano S. Microglia in Central Control of Metabolism. Physiology (Bethesda) 2024; 39:0. [PMID: 37962895 PMCID: PMC11283896 DOI: 10.1152/physiol.00021.2023] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2023] [Revised: 11/12/2023] [Accepted: 11/12/2023] [Indexed: 11/15/2023] Open
Abstract
Beyond their role as brain immune cells, microglia act as metabolic sensors in response to changes in nutrient availability, thus playing a role in energy homeostasis. This review highlights the evidence and challenges of studying the role of microglia in metabolism regulation.
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Affiliation(s)
- Jung Dae Kim
- Institute of Human Nutrition, Columbia University Irving Medical Center, New York, New York, United States
| | - Francesca Copperi
- Institute of Human Nutrition, Columbia University Irving Medical Center, New York, New York, United States
| | - Sabrina Diano
- Institute of Human Nutrition, Columbia University Irving Medical Center, New York, New York, United States
- Department of Molecular Pharmacology and Therapeutics, Columbia University Irving Medical Center, New York, New York, United States
- Department of Physiology and Cellular Biophysics, Columbia University Irving Medical Center, New York, New York, United States
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Asveda T, Priti T, Ravanan P. Exploring microglia and their phenomenal concatenation of stress responses in neurodegenerative disorders. Life Sci 2023:121920. [PMID: 37429415 DOI: 10.1016/j.lfs.2023.121920] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 07/05/2023] [Accepted: 07/06/2023] [Indexed: 07/12/2023]
Abstract
Neuronal cells are highly functioning but also extremely stress-sensitive cells. By defending the neuronal cells against pathogenic insults, microglial cells, a unique cell type, act as the frontline cavalry in the central nervous system (CNS). Their remarkable and unique ability to self-renew independently after their creation is crucial for maintaining normal brain function and neuroprotection. They have a wide range of molecular sensors that help maintain CNS homeostasis during development and adulthood. Despite being the protector of the CNS, studies have revealed that persistent microglial activation may be the root cause of innumerable neurodegenerative illnesses, including Alzheimer's disease (AD), Parkinson's disease (PD), and Amyloid Lateral Sclerosis (ALS). From our vigorous review, we state that there is a possible interlinking between pathways of Endoplasmic reticulum (ER) stress response, inflammation, and oxidative stress resulting in dysregulation of the microglial population, directly influencing the accumulation of pro-inflammatory cytokines, complement factors, free radicals, and nitric oxides leading to cell death via apoptosis. Recent research uses the suppression of these three pathways as a therapeutic approach to prevent neuronal death. Hence, in this review, we have spotlighted the advancement in microglial studies, which focus on their molecular defenses against multiple stresses, and current therapeutic strategies indirectly targeting glial cells for neurodevelopmental diseases.
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Affiliation(s)
- Thankavelu Asveda
- Functional Genomics Laboratory, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur 610005, Tamil Nadu, India
| | - Talwar Priti
- Apoptosis and Cell Survival Research Laboratory, 412G Pearl Research Park, School of Biosciences and Technology, Vellore Institute of Technology, Vellore 632014, Tamil Nadu, India.
| | - Palaniyandi Ravanan
- Functional Genomics Laboratory, Department of Microbiology, School of Life Sciences, Central University of Tamil Nadu, Thiruvarur 610005, Tamil Nadu, India.
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Wang M, Zhang J, Yin Z, Ding W, Zhao M, Liu J, Xu Y, Xu S, Pan W, Wei C, Jiang H, Wan J. Microglia-Mediated Neuroimmune Response Regulates Cardiac Remodeling After Myocardial Infarction. J Am Heart Assoc 2023; 12:e029053. [PMID: 37318008 PMCID: PMC10356026 DOI: 10.1161/jaha.122.029053] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2022] [Accepted: 05/01/2023] [Indexed: 06/16/2023]
Abstract
Background Sympathetic hyperactivity contributes to pathological remodeling after myocardial infarction (MI). However, the mechanisms underlying the increase in sympathetic activity remain unknown. Microglia are the predominant immune cells in the central nervous system and can regulate sympathetic neuron activity through neuroimmune response in the hypothalamic paraventricular nucleus. The present study aimed to investigate whether microglia-mediated neuroimmune response can regulate sympathetic activity and cardiac remodeling after MI. Methods and Results PLX3397 (pexidartinib) was used to deplete central microglia via intragastric injection or intracerebroventricular injection. After that, MI was induced by ligation of the left anterior descending coronary artery. Our study showed that MI resulted in the activation of microglia in the paraventricular nucleus. Microglia depletion, which was induced by PLX3397 treatment via intragastric injection or intracerebroventricular injection, improved cardiac function, reduced infarction size, and attenuated cardiomyocyte apoptosis, fibrosis, pathological electrical remodeling, and myocardial inflammation after MI. Mechanistically, these protective effects were associated with an attenuated neuroimmune response in the paraventricular nucleus, which contributed to the decrease of sympathetic activity and attenuation of sympathetic remodeling in the heart. However, intragastric injection with PLX3397 obviously depleted macrophages and induced neutrophil and T-lymphocyte disorders in the heart, blood, and spleen. Conclusions Microglia depletion in the central nervous system attenuates pathological cardiac remodeling after MI by inhibiting neuroimmune response and sympathetic activity. Intragastric administration of PLX3397 leads to serious deleterious effects in peripheral immune cells, especially macrophages, which should be a cause for concern in animal experiments and clinical practice.
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Affiliation(s)
- Menglong Wang
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
- Cardiovascular Research InstituteWuhan UniversityWuhanChina
- Hubei Key Laboratory of CardiologyWuhanChina
| | - Jishou Zhang
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
- Cardiovascular Research InstituteWuhan UniversityWuhanChina
- Hubei Key Laboratory of CardiologyWuhanChina
| | - Zheng Yin
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
- Cardiovascular Research InstituteWuhan UniversityWuhanChina
- Hubei Key Laboratory of CardiologyWuhanChina
| | - Wen Ding
- Department of RadiologyThe First Affiliated Hospital, Zhejiang University School of MedicineHangzhouChina
| | - Mengmeng Zhao
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
- Cardiovascular Research InstituteWuhan UniversityWuhanChina
- Hubei Key Laboratory of CardiologyWuhanChina
| | - Jianfang Liu
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
- Cardiovascular Research InstituteWuhan UniversityWuhanChina
- Hubei Key Laboratory of CardiologyWuhanChina
| | - Yao Xu
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
- Cardiovascular Research InstituteWuhan UniversityWuhanChina
- Hubei Key Laboratory of CardiologyWuhanChina
| | - Shuwan Xu
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
- Cardiovascular Research InstituteWuhan UniversityWuhanChina
- Hubei Key Laboratory of CardiologyWuhanChina
| | - Wei Pan
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
- Cardiovascular Research InstituteWuhan UniversityWuhanChina
- Hubei Key Laboratory of CardiologyWuhanChina
| | - Cheng Wei
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
- Cardiovascular Research InstituteWuhan UniversityWuhanChina
- Hubei Key Laboratory of CardiologyWuhanChina
| | - Hong Jiang
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
- Cardiovascular Research InstituteWuhan UniversityWuhanChina
- Hubei Key Laboratory of CardiologyWuhanChina
| | - Jun Wan
- Department of CardiologyRenmin Hospital of Wuhan UniversityWuhanChina
- Cardiovascular Research InstituteWuhan UniversityWuhanChina
- Hubei Key Laboratory of CardiologyWuhanChina
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Wang C, Ji Y, Zhang H, Ye Y, Zhang G, Zhang S, Zhao C, Wang Y. Increased level of exosomal miR-20b-5p derived from hypothermia-treated microglia promotes neurite outgrowth and synapse recovery after traumatic brain injury. Neurobiol Dis 2023; 179:106042. [PMID: 36804284 DOI: 10.1016/j.nbd.2023.106042] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Revised: 02/01/2023] [Accepted: 02/12/2023] [Indexed: 02/18/2023] Open
Abstract
Mild hypothermia has been proven to inhibit microglia activation after TBI. Exosomal microRNA derived from microglia played a critical role in promoting neurite outgrowth and synapse recovery. Here, we aimed to investigate the role of microRNAs in microglial exosomes after hypothermia treatment on neuronal regeneration after TBI. For in vitro study, stretch-injured neurons were co-cultured with microglial exosomes. For in vivo study, C57BL/6 mice were under controlled cortical impact and injected with microglial exosomes. The results showed that MG-LPS-EXOHT increased the number of dendrite branches and total length of dendrites both in vitro and in vivo, elevated the expression levels of PSD-95 and GluR1 in stretch-injured neurons, and increased spine density in the pericontusion region. Moreover, MG-LPS-EXOHT improved motor function and motor coordination. A high-throughput sequencing showed that miR-20b-5p was upregulated in MG-LPS-EXOHT. Elevating miR-20b-5p promoted neurite outgrowth and synapse recovery of injured neurons both in vitro and in vivo. Following mechanistic study demonstrated that miR-20b-5p might promote neurite outgrowth and synapse recovery by directly targeting PTEN and activating PI3K-AKT pathway. In conclusion, mild hypothermia could modify the microRNA prolife of exosomes derived from LPS activated BV2 cells. Furthermore, high level of microglial exosomal miR-20b-5p induced by mild hypothermia could transfer into injured neurons and promote neurite outgrowth and synapse recovery after TBI via activating the PI3K-AKT pathway by suppressing PTEN expression.
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Affiliation(s)
- Chuanfang Wang
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China; Department of Neurosurgery, the First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen, Guangdong, China
| | - Yunxiang Ji
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Huabin Zhang
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Yongyi Ye
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Guilong Zhang
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Shizhen Zhang
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Chengcheng Zhao
- Department of Neurosurgery, Affiliated Cancer Hospital and Institute of Guangzhou Medical University, Guangzhou, Guangdong, China; Department of Neurosurgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China.
| | - Yezhong Wang
- Department of Neurosurgery and Neurosurgical Disease Research Centre, the Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China.
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Varghese N, Morrison B. Partial Depletion of Microglia Attenuates Long-Term Potentiation Deficits following Repeated Blast Traumatic Brain Injury in Organotypic Hippocampal Slice Cultures. J Neurotrauma 2023; 40:547-560. [PMID: 36508265 PMCID: PMC10081725 DOI: 10.1089/neu.2022.0284] [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] [Indexed: 12/14/2022] Open
Abstract
Blast-induced traumatic brain injury (bTBI) has been a health concern in both military and civilian populations due to recent military and geopolitical conflicts. Military service members are frequently exposed to repeated bTBI throughout their training and deployment. Our group has previously reported compounding functional deficits as a result of increased number of blast exposures. In this study, we further characterized the decrease in long-term potentiation (LTP) by varying the blast injury severity and the inter-blast interval between two blast exposures. LTP deficits were attenuated with increasing inter-blast intervals. We also investigated changes in microglial activation; expression of CD68 was increased and expression of CD206 was decreased after multiple blast exposures. Expression of macrophage inflammatory protein (MIP)-1α, interleukin (IL)-1β, monocyte chemoattractant protein (MCP)-1, interferon gamma-inducible protein (IP)-10, and regulated on activation, normal T cell expressed and secreted (RANTES) increased, while expression of IL-10 decreased in the acute period after both single and repeated bTBI. By partially depleting microglia prior to injury, LTP deficits after injury were significantly reduced. Treatment with the novel drug, MW-189, prevented LTP deficits when administered immediately following a repeated bTBI and even when administered only for an acute period (24 h) between two blast injuries. These findings could inform the development of therapeutic strategies to treat the neurological deficits of repeated bTBI suggesting that microglia play a major role in functional neuronal deficits and may be a viable therapeutic target to lessen the neurophysiological deficits after bTBI.
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Affiliation(s)
- Nevin Varghese
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
| | - Barclay Morrison
- Department of Biomedical Engineering, Columbia University, New York, New York, USA
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10
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Met/HGFR triggers detrimental reactive microglia in TBI. Cell Rep 2022; 41:111867. [PMID: 36577378 DOI: 10.1016/j.celrep.2022.111867] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Revised: 10/17/2022] [Accepted: 11/30/2022] [Indexed: 12/29/2022] Open
Abstract
The complexity of signaling events and cellular responses unfolding in neuronal, glial, and immune cells upon traumatic brain injury (TBI) constitutes an obstacle in elucidating pathophysiological links and targets for intervention. We use array phosphoproteomics in a murine mild blunt TBI to reconstruct the temporal dynamics of tyrosine-kinase signaling in TBI and then scrutinize the large-scale effects of perturbation of Met/HGFR, VEGFR1, and Btk signaling by small molecules. We show Met/HGFR as a selective modifier of early microglial response and that Met/HGFR blockade prevents the induction of microglial inflammatory mediators, of reactive microglia morphology, and TBI-associated responses in neurons and vasculature. Both acute and prolonged Met/HGFR inhibition ameliorate neuronal survival and motor recovery. Early elevation of HGF itself in the cerebrospinal fluid of TBI patients suggests that this mechanism has translational value in human subjects. Our findings identify Met/HGFR as a modulator of early neuroinflammation in TBI with promising translational potential.
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11
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Wang Y, Wernersbach I, Strehle J, Li S, Appel D, Klein M, Ritter K, Hummel R, Tegeder I, Schäfer MKE. Early posttraumatic CSF1R inhibition via PLX3397 leads to time- and sex-dependent effects on inflammation and neuronal maintenance after traumatic brain injury in mice. Brain Behav Immun 2022; 106:49-66. [PMID: 35933030 DOI: 10.1016/j.bbi.2022.07.164] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 07/08/2022] [Accepted: 07/30/2022] [Indexed: 10/31/2022] Open
Abstract
BACKGROUND There is a need for early therapeutic interventions after traumatic brain injury (TBI) to prevent neurodegeneration. Microglia/macrophage (M/M) depletion and repopulation after treatment with colony stimulating factor 1 receptor (CSF1R) inhibitors reduces neurodegeneration. The present study investigates short- and long-term consequences after CSF1R inhibition during the early phase after TBI. METHODS Sex-matched mice were subjected to TBI and CSF1R inhibition by PLX3397 for 5 days and sacrificed at 5 or 30 days post injury (dpi). Neurological deficits were monitored and brain tissues were examined for histo- and molecular pathological markers. RNAseq was performed with 30 dpi TBI samples. RESULTS At 5 dpi, CSF1R inhibition attenuated the TBI-induced perilesional M/M increase and associated gene expressions by up to 50%. M/M attenuation did not affect structural brain damage at this time-point, impaired hematoma clearance, and had no effect on IL-1β expression. At 30 dpi, following drug discontinuation at 5 dpi and M/M repopulation, CSF1R inhibition attenuated brain tissue loss regardless of sex, as well as hippocampal atrophy and thalamic neuronal loss in male mice. Selected gene markers of brain inflammation and apoptosis were reduced in males but increased in females after early CSF1R inhibition as compared to corresponding TBI vehicle groups. Neurological outcome in behaving mice was almost not affected. RNAseq and gene set enrichment analysis (GSEA) of injured brains at 30 dpi revealed more genes associated with dendritic spines and synapse function after early CSF1R inhibition as compared to vehicle, suggesting improved neuronal maintenance and recovery. In TBI vehicle mice, GSEA showed high oxidative phosphorylation, oxidoreductase activity and ribosomal biogenesis suggesting oxidative stress and increased abundance of metabolically highly active cells. More genes associated with immune processes and phagocytosis in PLX3397 treated females vs males, suggesting sex-specific differences in response to early CSF1R inhibition after TBI. CONCLUSIONS M/M attenuation after CSF1R inhibition via PLX3397 during the early phase of TBI reduces long-term brain tissue loss, improves neuronal maintenance and fosters synapse recovery. Overall effects were not sex-specific but there is evidence that male mice benefit more than female mice.
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Affiliation(s)
- Yong Wang
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Isa Wernersbach
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Jenny Strehle
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Shuailong Li
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Dominik Appel
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Matthias Klein
- Institute for Immunology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Katharina Ritter
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Regina Hummel
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany
| | - Irmgard Tegeder
- Institute of Clinical Pharmacology, Goethe-University Frankfurt, Medical Faculty, Theodor Stern Kai 7, 60590 Frankfurt, Germany
| | - Michael K E Schäfer
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany; Focus Program Translational Neurosciences (FTN) of the Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany; Research Center for Immunotherapy (FZI), Johannes Gutenberg-University Mainz, Langenbeckstr. 1, 55131 Mainz, Germany.
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12
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Ball JB, Green-Fulgham SM, Watkins LR. Mechanisms of Microglia-Mediated Synapse Turnover and Synaptogenesis. Prog Neurobiol 2022; 218:102336. [DOI: 10.1016/j.pneurobio.2022.102336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/30/2022] [Accepted: 08/02/2022] [Indexed: 10/31/2022]
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13
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Gao X, Cao Z, Tan H, Li P, Su W, Wan T, Guo W. LncRNA, an Emerging Approach for Neurological Diseases Treatment by Regulating Microglia Polarization. Front Neurosci 2022; 16:903472. [PMID: 35860297 PMCID: PMC9289270 DOI: 10.3389/fnins.2022.903472] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 06/06/2022] [Indexed: 12/12/2022] Open
Abstract
Neurological disorders cause untold human disability and death each year. For most neurological disorders, the efficacy of their primary treatment strategies remains suboptimal. Microglia are associated with the development and progression of multiple neurological disorders. Targeting the regulation of microglia polarization has emerged as an important therapeutic strategy for neurological disorders. Their pro-inflammatory (M1)/anti-inflammatory (M2) phenotype microglia are closely associated with neuronal apoptosis, synaptic plasticity, blood-brain barrier integrity, resistance to iron death, and astrocyte regulation. LncRNA, a recently extensively studied non-coding transcript of over 200 nucleotides, has shown great value to intervene in microglia polarization. It can often participate in gene regulation of microglia by directly regulating transcription or sponging downstream miRNAs, for example. Through proper regulation, microglia can exert neuroprotective effects, reduce neurological damage and improve the prognosis of many neurological diseases. This paper reviews the progress of research linking lncRNAs to microglia polarization and neurological diseases.
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Affiliation(s)
- Xiaoyu Gao
- Hengyang Medical College, University of South China, Hengyang, Hunan, China
| | - Zilong Cao
- Hengyang Medical College, University of South China, Hengyang, Hunan, China
| | - Haifeng Tan
- Hengyang Medical College, University of South China, Hengyang, Hunan, China
| | - Peiling Li
- Hengyang Medical College, University of South China, Hengyang, Hunan, China
| | - Wenen Su
- Hengyang Medical College, University of South China, Hengyang, Hunan, China
| | - Teng Wan
- Sports Medicine Department, Huazhong University of Science and Technology Union Shenzhen Hospital, The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
- Hengyang Medical College, University of South China, Hengyang, Hunan, China
- Teng Wan,
| | - Weiming Guo
- Sports Medicine Department, Huazhong University of Science and Technology Union Shenzhen Hospital, The 6th Affiliated Hospital of Shenzhen University Health Science Center, Shenzhen, China
- *Correspondence: Weiming Guo,
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14
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Shi M, Mi L, Li F, Li Y, Zhou Y, Chen F, Liu L, Chai Y, Yang W, Zhang JN, Chen X. Fluvoxamine confers neuroprotection via inhibiting infiltration of peripheral leukocytes and M1 polarization of microglia/macrophages in a mouse model of traumatic brain injury. J Neurotrauma 2022; 39:1240-1261. [PMID: 35502478 DOI: 10.1089/neu.2021.0355] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Neuroinflammation is an important mediator of secondary injury pathogenesis which exerts dual beneficial and detrimental effects on pathophysiology of central nervous system (CNS) after traumatic brain injury (TBI). Fluvoxamine as a group of the Serotonin selective reuptake inhibitors (SSRIs) has been reported to have the anti-inflammatory properties. However, the mechanisms and therapeutic effects of Fluvoxamine in neuroinflammation after TBI have not be defined. In this study, we showed that Fluvoxamine inhibited peripheral immune cells infiltration and glia activation at 3 days in mice subjected to TBI. Fluvoxamine treatment promoted microglial/macrophages phenotypic transformation from pro-inflammatory M1-phenotype to anti-inflammatory M2-phenotype in vivo and vitro experiments. In addition, Fluvoxamine treatment attenuated neuronal apoptosis, blood-brain barrier disruption, cerebrovascular damage and posttraumatic edema formation, thereby improving neurological function of mice subjected to TBI. These findings support the clinical evaluation of Fluvoxamine as a neuroprotective therapy for TBI.
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Affiliation(s)
- Mingming Shi
- Tianjin Medical University General Hospital, 117865, No. 154, Anshan Road, Heping District, Tianjin, Tianjin, China, 300052;
| | - Liang Mi
- Tianjin Medical University General Hospital, 117865, Neurosurgery, Tianjin, Tianjin, China;
| | - Fanjian Li
- Tianjin Medical University General Hospital 154 Anshan Road, 300052, Department of Neurosurgery, Tianjin, China;
| | - Ying Li
- Tianjin Neurological Institute, 230967, Tianjin, Tianjin, China;
| | | | - Fanglian Chen
- Tianjin Neurological Institute, Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China;
| | | | - Yan Chai
- Tianjin Neurological Institute, 230967, Tianjin, China;
| | - Weidong Yang
- Tianjin Medical University General Hospital, 117865, Neurosurgery, Tianjin, Tianjin, China;
| | - Jian-Ning Zhang
- Tianjin Neurological Institute, General Hospital, Tianjin Medical University, Department of Neurosurgery, #154, Anshan Rd., Heping Dist. Tianjin, China P.R., Tianjin, China, 300052;
| | - Xin Chen
- Tianjin Medical University General Hospital, 117865, Neurosurgery, 154 Anshan Road, Heping District, Tianjin, Tianjin, China, 300052.,Tianjin Neurological Institute, 230967, 154 Anshan Road, Heping District, Tianjin, China, 300052;
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15
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Paasila PJ, Aramideh JA, Sutherland GT, Graeber MB. Synapses, Microglia, and Lipids in Alzheimer's Disease. Front Neurosci 2022; 15:778822. [PMID: 35095394 PMCID: PMC8789683 DOI: 10.3389/fnins.2021.778822] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 12/06/2021] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's disease (AD) is characterised by synaptic dysfunction accompanied by the microscopically visible accumulation of pathological protein deposits and cellular dystrophy involving both neurons and glia. Late-stage AD shows pronounced loss of synapses and neurons across several differentially affected brain regions. Recent studies of advanced AD using post-mortem brain samples have demonstrated the direct involvement of microglia in synaptic changes. Variants of the Apolipoprotein E and Triggering Receptors Expressed on Myeloid Cells gene represent important determinants of microglial activity but also of lipid metabolism in cells of the central nervous system. Here we review evidence that may help to explain how abnormal lipid metabolism, microglial activation, and synaptic pathophysiology are inter-related in AD.
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Affiliation(s)
- Patrick J. Paasila
- Charles Perkins Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Jason A. Aramideh
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
| | - Greg T. Sutherland
- Charles Perkins Centre, School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
| | - Manuel B. Graeber
- Brain and Mind Centre, Faculty of Medicine and Health, The University of Sydney, Camperdown, NSW, Australia
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16
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Krukowski K. Short review: The impact of sex on neuroimmune and cognitive outcomes after traumatic brain injury. Brain Behav Immun Health 2021; 16:100327. [PMID: 34589813 PMCID: PMC8474220 DOI: 10.1016/j.bbih.2021.100327] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 08/06/2021] [Accepted: 08/09/2021] [Indexed: 11/22/2022] Open
Abstract
Traumatic brain injury (TBI) is an ever growing health concern, with cases increasing in both the US and the world at large. With the improvement of emergency medicine in recent decades, survival from TBI has become more common place, and thus individuals are coping with long-term deleterious outcomes from trauma as a result. Such outcomes include altered cognitive (memory loss/executive function), social (isolation tendencies), and behavioral (risk-taking behavior/anxiety) function. Researchers use preclinical rodent models to investigate cellular and molecular underpinnings of adverse TBI outcomes. One leading mechanism of long-term cognitive changes include alterations of immune function in the brain (termed 'neuroimmune'). Studies have found that TBI can induce chronic maladaptive neuroimmune responses, which can in turn propagate long-term neurological deficits. Unfortunately, most of the molecular understanding of TBI-induced neuroimmune outcomes is derived from studies performed solely in males. This is especially problematic as sex-dimorphic neuroimmune changes have been identified in healthy individuals. If and how these basal neuroimmune differences influence TBI related outcomes is the focus of this short review. Importantly, understanding these differences could allow for improved therapeutic development for treating the long-term effects of TBI.
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Affiliation(s)
- Karen Krukowski
- Department of Biological Sciences, Division of Natural Sciences and Mathematics, University of Denver, Denver, CO, USA
- Knoebel Institute for Healthy Aging, University of Denver, Denver, CO, USA
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17
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Ettcheto M, Cano A, Sanchez-López E, Verdaguer E, Folch J, Auladell C, Camins A. Masitinib for the treatment of Alzheimer's disease. Neurodegener Dis Manag 2021; 11:263-276. [PMID: 34412534 DOI: 10.2217/nmt-2021-0019] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
The actual standard treatment for mild-to-moderately severe Alzheimer's disease only attacks its symptoms. Masitinib is a potent and selective phenylaminothiazole-type tyrosine kinase inhibitor which is currently in Phase III studies for the treatment of Alzheimer's disease (AD) with the aim of modifying its evolution and with multiple pharmacological targets such as inhibition of mast cells activity, inhibition of microglia activation, modulation of Aβ and Tau protein signaling pathway and prevention of synaptic damage. Here, we review the preclinical and clinical studies that investigated the administration of masitinib treatment in monotherapy in AD. All research studies revealed positive effects concerning the cognitive functions in AD and generally with good safety and tolerability.
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Affiliation(s)
- Miren Ettcheto
- Department of Pharmacology, Toxicology & Therapeutic Chemistry, Faculty of Pharmacy & Food Sciences, University of Barcelona, Spain.,Institut de Neurociències (UBNeuro), University of Barcelona, Spain.,Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
| | - Amanda Cano
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain.,Department of Pharmacy, Pharmaceutical Technology & Physical Chemistry, Faculty of Pharmacy & Food Sciences, University of Barcelona, Spain.,Research Center & Memory Clinic, Fundació ACE. Institut Català de Neurociències Aplicades - International University of Catalunya (UIC), Barcelona, Spain
| | - Elena Sanchez-López
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain.,Department of Pharmacy, Pharmaceutical Technology & Physical Chemistry, Faculty of Pharmacy & Food Sciences, University of Barcelona, Spain
| | - Ester Verdaguer
- Department of Cellular Biology, Physiology & Immunology, Faculty of Biology, University of Barcelona, Spain
| | - Jaume Folch
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain.,Unit of Biochemistry & Pharmacology, Faculty of Medicine & Health Sciences, University of Rovira i Virgili, Reus (Tarragona), Spain
| | - Carme Auladell
- Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain.,Department of Cellular Biology, Physiology & Immunology, Faculty of Biology, University of Barcelona, Spain
| | - Antoni Camins
- Department of Pharmacology, Toxicology & Therapeutic Chemistry, Faculty of Pharmacy & Food Sciences, University of Barcelona, Spain.,Institut de Neurociències (UBNeuro), University of Barcelona, Spain.,Biomedical Research Networking Centre in Neurodegenerative Diseases (CIBERNED), Madrid, Spain
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18
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Buchmann Godinho D, da Silva Fiorin F, Schneider Oliveira M, Furian AF, Rechia Fighera M, Freire Royes LF. The immunological influence of physical exercise on TBI-induced pathophysiology: Crosstalk between the spleen, gut, and brain. Neurosci Biobehav Rev 2021; 130:15-30. [PMID: 34400178 DOI: 10.1016/j.neubiorev.2021.08.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 08/04/2021] [Accepted: 08/08/2021] [Indexed: 12/16/2022]
Abstract
Traumatic brain injury (TBI) is a non-degenerative and non-congenital insult to the brain and is recognized as a global public health problem, with a high incidence of neurological disorders. Despite the causal relationship not being entirely known, it has been suggested that multiorgan inflammatory response involving the autonomic nervous system and the spleen-gut brain axis dysfunction exacerbate the TBI pathogenesis in the brain. Thus, applying new therapeutic tools, such as physical exercise, have been described in the literature to act on the immune modulation induced by brain injuries. However, there are caveats to consider when interpreting the effects of physical exercise on this neurological injury. Given the above, this review will highlight the main findings of the literature involving peripheral immune responses in TBI-induced neurological damage and how changes in the cellular metabolism of the spleen-gut brain axis elicited by different protocols of physical exercise alter the pathophysiology induced by this neurological injury.
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Affiliation(s)
- Douglas Buchmann Godinho
- Laboratório de Bioquímica do Exercício, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil; Programa de Pós-Graduação em Bioquímica Toxicológica, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Fernando da Silva Fiorin
- Programa de Pós-Graduação em Neuroengenharia, Instituto Internacional de Neurociências Edmond e Lily Safra, Instituto Santos Dumont, Macaíba, RN, Brazil
| | - Mauro Schneider Oliveira
- Centro de Ciências da Saúde, Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Ana Flavia Furian
- Centro de Ciências da Saúde, Programa de Pós-Graduação em Farmacologia, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
| | - Michele Rechia Fighera
- Laboratório de Bioquímica do Exercício, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil; Centro de Ciências da Saúde, Departamento de Clínica Médica e Pediatria, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil
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19
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Zhao C, Deng Y, He Y, Huang X, Wang C, Li W. Decreased Level of Exosomal miR-5121 Released from Microglia Suppresses Neurite Outgrowth and Synapse Recovery of Neurons Following Traumatic Brain Injury. Neurotherapeutics 2021; 18:1273-1294. [PMID: 33475953 PMCID: PMC8423926 DOI: 10.1007/s13311-020-00999-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/20/2020] [Indexed: 10/22/2022] Open
Abstract
Activated microglia can suppress neurite outgrowth and synapse recovery in the acute stage following traumatic brain injury (TBI). However, the underlying mechanism has not been clearly elucidated. Exosomes derived from microglia have been reported to play a critical role in microglia-neuron interaction in healthy and pathological brains. Here, we aimed to investigate the role of microglia-derived exosomes in regulating neurite outgrowth and synapse recovery following TBI. In our study, exosomes derived from microglia were co-cultured with stretch-injured neurons in vitro and intravenously injected into mice that underwent fluid percussion injury (FPI) by tail vein injection in vivo. The results showed that microglia-derived exosomes could be absorbed by neurons in vitro and in vivo. Moreover, exosomes derived from stretch-injured microglia decreased the protein levels of GAP43, PSD-95, GluR1, and Synaptophysin and dendritic complexity in stretch-injured neurons in vitro, and reduced GAP43+ NEUN cell percentage and apical dendritic spine density in the pericontusion region in vivo. Motor coordination was also impaired in mice treated with stretch-injured microglia-derived exosomes after FPI. A microRNA microarray showed that the level of miR-5121 was decreased most greatly in exosomes derived from stretch-injured microglia. Overexpression of miR-5121 in stretch-injured microglia-derived exosomes partly reversed the suppression of neurite outgrowth and synapse recovery of neurons both in vitro and in vivo. Moreover, motor coordination in miR-5121 overexpressed exosomes treated mice was significantly improved after FPI. Following mechanistic study demonstrated that miR-5121 might promote neurite outgrowth and synapse recovery by directly targeting RGMa. In conclusion, our finding revealed a novel exosome-mediated mechanism of microglia-neuron interaction that suppressed neurite outgrowth and synapse recovery of neurons following TBI.
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Affiliation(s)
- Chengcheng Zhao
- Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, 3002 Sungang Road, Shenzhen, Guangdong, China
- Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, School of Biomedical Engineering, Shenzhen University Health Science Center, Shenzhen, Guangdong, China
| | - Yuefei Deng
- Department of Neurosurgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Yi He
- Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, 3002 Sungang Road, Shenzhen, Guangdong, China
| | - Xianjian Huang
- Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, 3002 Sungang Road, Shenzhen, Guangdong, China
| | - Chuanfang Wang
- Department of Neurosurgery and Neurosurgical Disease Research Centre, The Second Affiliated Hospital of Guangzhou Medical University, 250 Changgang East Road, Guangzhou, Guangdong, China.
| | - Weiping Li
- Department of Neurosurgery, The First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, 3002 Sungang Road, Shenzhen, Guangdong, China.
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20
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Yegla B, Boles J, Kumar A, Foster TC. Partial microglial depletion is associated with impaired hippocampal synaptic and cognitive function in young and aged rats. Glia 2021; 69:1494-1514. [PMID: 33586813 DOI: 10.1002/glia.23975] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 01/25/2021] [Accepted: 01/26/2021] [Indexed: 12/11/2022]
Abstract
The role of microglia in mediating age-related changes in cognition and hippocampal synaptic function was examined by microglial depletion and replenishment using PLX3397. We observed age-related differences in microglial number and morphology, as well as increased Iba-1 expression, indicating microglial activation. PLX3397 treatment decreased microglial number, with aged rats exhibiting the lowest density. Young rats exhibited increased expression of pro-inflammatory cytokines during depletion and repopulation and maintenance of Iba-1 levels despite reduced microglial number. For aged rats, several cytokines increased with depletion and recovered during repopulation; however, aged rats did not fully recover microglial cell number or Iba-1 expression during repopulation, with a recovery comparable to young control levels rather than aged controls. Hippocampal CA3-CA1 synaptic transmission was impaired with age, and microglial depletion was associated with decreased total synaptic transmission in young and aged rats. A robust decline in N-methyl-d-aspartate-receptor-mediated synaptic transmission arose in young depleted rats specifically. Microglial replenishment normalized depletion-induced synaptic function to control levels; however, recovery of aged animals did not mirror young. Microglial depletion was associated with decreased context-object discrimination memory in both age groups, which recovered with microglial repopulation. Aged rats displayed impaired contextual and cued fear memory, and microglial replenishment did not recover their memory to the level of young. The current study indicates that cognitive function and synaptic transmission benefit from the support of aged microglia and are hindered by removal of these cells. Replenishment of microglia in aging did not ameliorate age-related cognitive impairments or senescent synaptic function.
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Affiliation(s)
- Brittney Yegla
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
| | - Jake Boles
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
| | - Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA
| | - Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, Florida, USA.,Genetics and Genomics Program, University of Florida, Gainesville, Florida, USA
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21
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Clark LR, Yun S, Acquah NK, Kumar PL, Metheny HE, Paixao RCC, Cohen AS, Eisch AJ. Mild Traumatic Brain Injury Induces Transient, Sequential Increases in Proliferation, Neuroblasts/Immature Neurons, and Cell Survival: A Time Course Study in the Male Mouse Dentate Gyrus. Front Neurosci 2021; 14:612749. [PMID: 33488351 PMCID: PMC7817782 DOI: 10.3389/fnins.2020.612749] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 12/02/2020] [Indexed: 12/17/2022] Open
Abstract
Mild traumatic brain injuries (mTBIs) are prevalent worldwide. mTBIs can impair hippocampal-based functions such as memory and cause network hyperexcitability of the dentate gyrus (DG), a key entry point to hippocampal circuitry. One candidate for mediating mTBI-induced hippocampal cognitive and physiological dysfunction is injury-induced changes in the process of DG neurogenesis. There are conflicting results on how TBI impacts the process of DG neurogenesis; this is not surprising given that both the neurogenesis process and the post-injury period are dynamic, and that the quantification of neurogenesis varies widely in the literature. Even within the minority of TBI studies focusing specifically on mild injuries, there is disagreement about if and how mTBI changes the process of DG neurogenesis. Here we utilized a clinically relevant rodent model of mTBI (lateral fluid percussion injury, LFPI), gold-standard markers and quantification of the neurogenesis process, and three time points post-injury to generate a comprehensive picture of how mTBI affects adult hippocampal DG neurogenesis. Male C57BL/6J mice (6-8 weeks old) received either sham surgery or mTBI via LFPI. Proliferating cells, neuroblasts/immature neurons, and surviving cells were quantified via stereology in DG subregions (subgranular zone [SGZ], outer granule cell layer [oGCL], molecular layer, and hilus) at short-term (3 days post-injury, dpi), intermediate (7 dpi), and long-term (31 dpi) time points. The data show this model of mTBI induces transient, sequential increases in ipsilateral SGZ/GCL proliferating cells, neuroblasts/immature neurons, and surviving cells which is suggestive of mTBI-induced neurogenesis. In contrast to these ipsilateral hemisphere findings, measures in the contralateral hemisphere were not increased in key neurogenic DG subregions after LFPI. Our work in this mTBI model is in line with most literature on other and more severe models of TBI in showing TBI stimulates the process of DG neurogenesis. However, as our DG data in mTBI provide temporal, subregional, and neurogenesis-stage resolution, these data are important to consider in regard to the functional importance of TBI-induction of the neurogenesis process and future work assessing the potential of replacing and/or repairing DG neurons in the brain after TBI.
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Affiliation(s)
- Lyles R. Clark
- Department of Anesthesiology and Critical Care Medicine, The Children’s Hospital of Philadelphia (CHOP) Research Institute, Philadelphia, PA, United States
- Mahoney Institute for Neurosciences, Perelman School of Medicine, Philadelphia, PA, United States
| | - Sanghee Yun
- Department of Anesthesiology and Critical Care Medicine, The Children’s Hospital of Philadelphia (CHOP) Research Institute, Philadelphia, PA, United States
- Mahoney Institute for Neurosciences, Perelman School of Medicine, Philadelphia, PA, United States
| | - Nana K. Acquah
- Department of Anesthesiology and Critical Care Medicine, The Children’s Hospital of Philadelphia (CHOP) Research Institute, Philadelphia, PA, United States
- Biological Basis of Behavior Program, University of Pennsylvania, Philadelphia, PA, United States
| | - Priya L. Kumar
- Department of Anesthesiology and Critical Care Medicine, The Children’s Hospital of Philadelphia (CHOP) Research Institute, Philadelphia, PA, United States
- Biomechanical Engineering, University of Pennsylvania, Philadelphia, PA, United States
| | - Hannah E. Metheny
- Department of Anesthesiology and Critical Care Medicine, The Children’s Hospital of Philadelphia (CHOP) Research Institute, Philadelphia, PA, United States
| | - Rikley C. C. Paixao
- Department of Anesthesiology and Critical Care Medicine, The Children’s Hospital of Philadelphia (CHOP) Research Institute, Philadelphia, PA, United States
| | - Akivas S. Cohen
- Department of Anesthesiology and Critical Care Medicine, The Children’s Hospital of Philadelphia (CHOP) Research Institute, Philadelphia, PA, United States
- Mahoney Institute for Neurosciences, Perelman School of Medicine, Philadelphia, PA, United States
| | - Amelia J. Eisch
- Department of Anesthesiology and Critical Care Medicine, The Children’s Hospital of Philadelphia (CHOP) Research Institute, Philadelphia, PA, United States
- Mahoney Institute for Neurosciences, Perelman School of Medicine, Philadelphia, PA, United States
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22
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Henry RJ, Loane DJ. Targeting chronic and evolving neuroinflammation following traumatic brain injury to improve long-term outcomes: insights from microglial-depletion models. Neural Regen Res 2021; 16:976-977. [PMID: 33229740 PMCID: PMC8178770 DOI: 10.4103/1673-5374.297068] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Affiliation(s)
- Rebecca J Henry
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, USA
| | - David J Loane
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD, USA; School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
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23
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Paladini MS, Feng X, Krukowski K, Rosi S. Microglia depletion and cognitive functions after brain injury: From trauma to galactic cosmic ray. Neurosci Lett 2021; 741:135462. [DOI: 10.1016/j.neulet.2020.135462] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/21/2020] [Accepted: 10/22/2020] [Indexed: 12/20/2022]
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24
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Abstract
Traumatic brain injury is among the leading causes of death in individuals under 45 years of age. However, since trauma mechanisms and survival times differ enormously, the exact mechanisms leading to the primary and secondary injury and eventually to death after traumatic brain injury (TBI) remain unclear. Several studies showed the versatile functions of microglia, the innate macrophages of the brain, following a TBI. Earlier being characterized as rather neurotoxic, neuroprotective capacities were recently demonstrated, therefore, making microglia one of the key players following TBI. Especially in cases with only short survival times, immediate microglial reactions are of great forensic interest in questions of wound age estimation. Using standardized immunohistochemical methods, we examined 8 cases which died causatively of TBI with survival times between minutes and 7 days and 5 control cases with cardiovascular failure as the cause of death to determine acute changes in microglial morphology and antigen expression after TBI. In this pilot study, we detected highly localized changes in microglial morphology already early after traumatic damage, e.g., activated microglia and phagocyted erythrocytes in the contusion areas in cases with minute survival. Furthermore, an altered antigen expression was observed with increasing trauma wound age, showing similar effects like earlier transcriptomic studies. There is minute data on the direct impact of shear forces on microglial morphology. We were able to show localization-depending effects on microglial morphology causing localized dystrophy and adjacent activation. While rodent studies are widespread, they fail to mimic the exact mechanisms in human TBI response. Therefore, more studies focusing on cadaveric samples need to follow to thoroughly define the mechanisms leading to cell destruction and eventually evaluate their forensic value.
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25
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Xie D, He M, Hu X. Microglia/macrophage diversities in central nervous system physiology and pathology. CNS Neurosci Ther 2020; 25:1287-1289. [PMID: 31793210 PMCID: PMC7154592 DOI: 10.1111/cns.13257] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 10/21/2019] [Accepted: 10/21/2019] [Indexed: 12/30/2022] Open
Affiliation(s)
- Di Xie
- Pittsburgh Institute of Brain Disorders and Recovery, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Maxine He
- Neuroscience Program, University of Illinois at Urbana-Champaign, Champaign, IL, USA
| | - Xiaoming Hu
- Pittsburgh Institute of Brain Disorders and Recovery, Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
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26
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Ritzel RM, He J, Li Y, Cao T, Khan N, Shim B, Sabirzhanov B, Aubrecht T, Stoica BA, Faden AI, Wu LJ, Wu J. Proton extrusion during oxidative burst in microglia exacerbates pathological acidosis following traumatic brain injury. Glia 2020; 69:746-764. [PMID: 33090575 PMCID: PMC7819364 DOI: 10.1002/glia.23926] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2020] [Revised: 10/01/2020] [Accepted: 10/07/2020] [Indexed: 01/02/2023]
Abstract
Acidosis is among the least studied secondary injury mechanisms associated with neurotrauma. Acute decreases in brain pH correlate with poor long‐term outcome in patients with traumatic brain injury (TBI), however, the temporal dynamics and underlying mechanisms are unclear. As key drivers of neuroinflammation, we hypothesized that microglia directly regulate acidosis after TBI, and thereby, worsen neurological outcomes. Using a controlled cortical impact model in adult male mice we demonstrate that intracellular pH in microglia and extracellular pH surrounding the lesion site are significantly reduced for weeks after injury. Microglia proliferation and production of reactive oxygen species (ROS) were also increased during the first week, mirroring the increase in extracellular ROS levels seen around the lesion site. Microglia depletion by a colony stimulating factor 1 receptor (CSF1R) inhibitor, PLX5622, markedly decreased extracellular acidosis, ROS production, and inflammation in the brain after injury. Mechanistically, we identified that the voltage‐gated proton channel Hv1 promotes oxidative burst activity and acid extrusion in microglia. Compared to wildtype controls, microglia lacking Hv1 showed reduced ability to generate ROS and extrude protons. Importantly, Hv1‐deficient mice exhibited reduced pathological acidosis and inflammation after TBI, leading to long‐term neuroprotection and functional recovery. Our data therefore establish the microglial Hv1 proton channel as an important link that integrates inflammation and acidosis within the injury microenvironment during head injury.
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Affiliation(s)
- Rodney M Ritzel
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Junyun He
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Yun Li
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Tuoxin Cao
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Niaz Khan
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Bosung Shim
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Boris Sabirzhanov
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Taryn Aubrecht
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Bogdan A Stoica
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Alan I Faden
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, USA.,University of Maryland Center to Advance Chronic Pain Research, University of Maryland, Baltimore, Maryland, USA
| | - Long-Jun Wu
- Department of Neurology, Mayo Clinic, Rochester, Minnesota, USA
| | - Junfang Wu
- Department of Anesthesiology and Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland School of Medicine, Baltimore, Maryland, USA.,University of Maryland Center to Advance Chronic Pain Research, University of Maryland, Baltimore, Maryland, USA
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27
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Green KN, Crapser JD, Hohsfield LA. To Kill a Microglia: A Case for CSF1R Inhibitors. Trends Immunol 2020; 41:771-784. [PMID: 32792173 PMCID: PMC7484341 DOI: 10.1016/j.it.2020.07.001] [Citation(s) in RCA: 122] [Impact Index Per Article: 30.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2019] [Revised: 07/02/2020] [Accepted: 07/07/2020] [Indexed: 12/12/2022]
Abstract
Microglia, the brain's immune sentinels, have garnered much attention in recent years. Researchers have begun to identify the manifold roles that these cells play in the central nervous system (CNS), and this work has been greatly facilitated by microglial depletion paradigms. The varying degrees of spatiotemporal manipulation afforded by such techniques allow microglial ablation before, during, and/or following insult, injury, or disease. We review the major methods of microglial depletion, including toxin-based, genetic, and pharmacological approaches, which differ in key factors including depletion onset, duration, and off-target effects. We conclude that pharmacological CSF1R inhibitors afford the most extensive versatility in manipulating microglia, making them ideal candidates for future studies investigating microglial function in health and disease.
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Affiliation(s)
- Kim N Green
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697, USA.
| | - Joshua D Crapser
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697, USA
| | - Lindsay A Hohsfield
- Department of Neurobiology and Behavior, University of California, Irvine, CA 92697, USA
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28
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O'Reilly ML, Tom VJ. Neuroimmune System as a Driving Force for Plasticity Following CNS Injury. Front Cell Neurosci 2020; 14:187. [PMID: 32792908 PMCID: PMC7390932 DOI: 10.3389/fncel.2020.00187] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 05/29/2020] [Indexed: 12/15/2022] Open
Abstract
Following an injury to the central nervous system (CNS), spontaneous plasticity is observed throughout the neuraxis and affects multiple key circuits. Much of this spontaneous plasticity can elicit beneficial and deleterious functional outcomes, depending on the context of plasticity and circuit affected. Injury-induced activation of the neuroimmune system has been proposed to be a major factor in driving this plasticity, as neuroimmune and inflammatory factors have been shown to influence cellular, synaptic, structural, and anatomical plasticity. Here, we will review the mechanisms through which the neuroimmune system mediates plasticity after CNS injury. Understanding the role of specific neuroimmune factors in driving adaptive and maladaptive plasticity may offer valuable therapeutic insight into how to promote adaptive plasticity and/or diminish maladaptive plasticity, respectively.
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Affiliation(s)
- Micaela L O'Reilly
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Veronica J Tom
- Department of Neurobiology and Anatomy, Marion Murray Spinal Cord Research Center, Drexel University College of Medicine, Philadelphia, PA, United States
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29
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Lier J, Ondruschka B, Bechmann I, Dreßler J. Fast microglial activation after severe traumatic brain injuries. Int J Legal Med 2020; 134:2187-2193. [PMID: 32372233 PMCID: PMC7578125 DOI: 10.1007/s00414-020-02308-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2020] [Accepted: 04/22/2020] [Indexed: 12/17/2022]
Abstract
Traumatic brain injury is among the leading causes of death in individuals under 45 years of age. However, since trauma mechanisms and survival times differ enormously, the exact mechanisms leading to the primary and secondary injury and eventually to death after traumatic brain injury (TBI) remain unclear. Several studies showed the versatile functions of microglia, the innate macrophages of the brain, following a TBI. Earlier being characterized as rather neurotoxic, neuroprotective capacities were recently demonstrated, therefore, making microglia one of the key players following TBI. Especially in cases with only short survival times, immediate microglial reactions are of great forensic interest in questions of wound age estimation. Using standardized immunohistochemical methods, we examined 8 cases which died causatively of TBI with survival times between minutes and 7 days and 5 control cases with cardiovascular failure as the cause of death to determine acute changes in microglial morphology and antigen expression after TBI. In this pilot study, we detected highly localized changes in microglial morphology already early after traumatic damage, e.g., activated microglia and phagocyted erythrocytes in the contusion areas in cases with minute survival. Furthermore, an altered antigen expression was observed with increasing trauma wound age, showing similar effects like earlier transcriptomic studies. There is minute data on the direct impact of shear forces on microglial morphology. We were able to show localization-depending effects on microglial morphology causing localized dystrophy and adjacent activation. While rodent studies are widespread, they fail to mimic the exact mechanisms in human TBI response. Therefore, more studies focusing on cadaveric samples need to follow to thoroughly define the mechanisms leading to cell destruction and eventually evaluate their forensic value.
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Affiliation(s)
- Julia Lier
- Institute of Anatomy, University of Leipzig, Liebigstraße 13, D-04103, Leipzig, Germany
| | - Benjamin Ondruschka
- Institute of Legal Medicine, University of Leipzig, Johannisallee 28, D-04103, Leipzig, Germany.
| | - Ingo Bechmann
- Institute of Anatomy, University of Leipzig, Liebigstraße 13, D-04103, Leipzig, Germany
| | - Jan Dreßler
- Institute of Legal Medicine, University of Leipzig, Johannisallee 28, D-04103, Leipzig, Germany
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30
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Abstract
Traumatic brain injury (TBI) is the leading cause of morbidity and mortality worldwide. Although TBI leads to mechanical damage during initial impact, secondary damage also occurs as results from delayed neurochemical process and intracellular signaling pathways. Accumulated animal and human studies demonstrated that apoptotic mechanism contributes to overall pathology of TBI. Apoptotic cell death has been identified within contusional brain lesion at acute phase of TBI and in region remote from the site directly injured in days to weeks after trauma. TBI is also dynamic conditions that cause neuronal decline overtime and is likely due to neurodegenerative mechanisms years after trauma. Current studies have even suggested association of neuronal damage through apoptotic pathway with mild TBI, which contributes chronic persistent neurological symptoms and cognitive deficits. Thus, a better understanding of the acute and chronic consequences of apoptosis following TBI is required. The purpose of this review is to describe (1) neuronal apoptotic pathway following TBI, (2) contribution of apoptosis to acute and chronic phase of TBI, and (3) current treatment targeting on apoptotic pathway.
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Affiliation(s)
- Yosuke Akamatsu
- Division of Neurosurgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
- Department of Neurosurgery, Iwate Medical University, Morioka, Japan
| | - Khalid A Hanafy
- Department of Neurology, Harvard Medical School, Boston, MA, USA.
- Division of Neurointensive Care, Beth Israel Deaconess Medical Center, Harvard Medical School, 3 Blackfan Circle Rm 639, Boston, MA, 02115, USA.
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31
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Wen RX, Shen H, Huang SX, Wang LP, Li ZW, Peng P, Mamtilahun M, Tang YH, Shen FX, Tian HL, Yang GY, Zhang ZJ. P2Y6 receptor inhibition aggravates ischemic brain injury by reducing microglial phagocytosis. CNS Neurosci Ther 2020; 26:416-429. [PMID: 32154670 PMCID: PMC7080436 DOI: 10.1111/cns.13296] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Revised: 02/01/2020] [Accepted: 02/01/2020] [Indexed: 02/06/2023] Open
Abstract
Introduction Clearance of damaged cells and debris is beneficial for the functional recovery after ischemic brain injury. However, the specific phagocytic receptor that mediates microglial phagocytosis after ischemic stroke is unknown. Aim To investigate whether P2Y6 receptor‐mediated microglial phagocytosis is beneficial for the debris clearance and functional recovery after ischemic stroke. Results The expression of the P2Y6 receptor in microglia increased within 3 days after transient middle cerebral artery occlusion. Inhibition of microglial phagocytosis by the selective inhibitor MRS2578 enlarged the brain atrophy and edema volume after ischemic stroke, subsequently aggravated neurological function as measured by modified neurological severity scores and Grid walking test. MRS2578 treatment had no effect on the expression of IL‐1α, IL‐1β, IL‐6, IL‐10, TNF‐α, TGF‐β, and MPO after ischemic stroke. Finally, we found that the expression of myosin light chain kinase decreased after microglial phagocytosis inhibition in the ischemic mouse brain, which suggested that myosin light chain kinase was involved in P2Y6 receptor‐mediated phagocytosis. Conclusion Our results indicate that P2Y6 receptor‐mediated microglial phagocytosis plays a beneficial role during the acute stage of ischemic stroke, which can be a therapeutic target for ischemic stroke.
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Affiliation(s)
- Ruo-Xue Wen
- Shanghai JiaoTong Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Hui Shen
- Shanghai JiaoTong Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Shu-Xian Huang
- Shanghai JiaoTong Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Li-Ping Wang
- Department of Neurology, School of Medicine, Ruijin Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Zong-Wei Li
- Shanghai JiaoTong Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Peng Peng
- Shanghai JiaoTong Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Muyassar Mamtilahun
- Shanghai JiaoTong Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Yao-Hui Tang
- Shanghai JiaoTong Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
| | - Fan-Xia Shen
- Department of Neurology, School of Medicine, Ruijin Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Heng-Li Tian
- Department of Neurosurgery, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Guo-Yuan Yang
- Shanghai JiaoTong Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China.,Department of Neurology, School of Medicine, Ruijin Hospital, Shanghai Jiao Tong University, Shanghai, China
| | - Zhi-Jun Zhang
- Shanghai JiaoTong Affiliated Sixth People's Hospital, School of Biomedical Engineering, Shanghai Jiao Tong University, Shanghai, China
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32
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Chd8 Rescued TBI-Induced Neurological Deficits by Suppressing Apoptosis and Autophagy Via Wnt Signaling Pathway. Cell Mol Neurobiol 2020; 40:1165-1184. [DOI: 10.1007/s10571-020-00806-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 01/30/2020] [Indexed: 12/30/2022]
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