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Heuer SE, Bloss EB, Howell GR. Strategies to dissect microglia-synaptic interactions during aging and in Alzheimer's disease. Neuropharmacology 2024; 254:109987. [PMID: 38705570 DOI: 10.1016/j.neuropharm.2024.109987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2024] [Revised: 04/29/2024] [Accepted: 05/02/2024] [Indexed: 05/07/2024]
Abstract
Age is the largest risk factor for developing Alzheimer's disease (AD), a neurodegenerative disorder that causes a progressive and severe dementia. The underlying cause of cognitive deficits seen in AD is thought to be the disconnection of neural circuits that control memory and executive functions. Insight into the mechanisms by which AD diverges from normal aging will require identifying precisely which cellular events are driven by aging and which are impacted by AD-related pathologies. Since microglia, the brain-resident macrophages, are known to have critical roles in the formation and maintenance of neural circuits through synaptic pruning, they are well-positioned to modulate synaptic connectivity in circuits sensitive to aging or AD. In this review, we provide an overview of the current state of the field and on emerging technologies being employed to elucidate microglia-synaptic interactions in aging and AD. We also discuss the importance of leveraging genetic diversity to study how these interactions are shaped across more realistic contexts. We propose that these approaches will be essential to define specific aging- and disease-relevant trajectories for more personalized therapeutics aimed at reducing the effects of age or AD pathologies on the brain. This article is part of the Special Issue on "Microglia".
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Affiliation(s)
- Sarah E Heuer
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA; Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA
| | - Erik B Bloss
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA; Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA; Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, 04469, USA.
| | - Gareth R Howell
- The Jackson Laboratory, Bar Harbor, ME, 04609, USA; Graduate School of Biomedical Sciences, Tufts University School of Medicine, Boston, MA, 02111, USA; Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, ME, 04469, USA.
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2
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Verkhratsky A, Zorec R. Neuroglia in cognitive reserve. Mol Psychiatry 2024:10.1038/s41380-024-02644-z. [PMID: 38956370 DOI: 10.1038/s41380-024-02644-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/09/2024] [Revised: 06/18/2024] [Accepted: 06/21/2024] [Indexed: 07/04/2024]
Abstract
The concept of cognitive reserve was born to account for the disjunction between the objective extent of brain damage in pathology and its clinical and intellectual outcome. The cognitive reserve comprises structural (brain reserve) and functional (brain maintenance, resilience, compensation) aspects of the nervous tissue reflecting exposome-driven life-long plasticity, which defines the ability of the brain to withstand aging and pathology. The mechanistic background of this concept was primarily focused on adaptive changes in neurones and neuronal networks. We present arguments favoring the more inclusive view, positing that neuroglia are fundamental for defining the cognitive reserve through homeostatic, neuroprotective, and neurodegenerative mechanisms. Neuroglia are critical for the life-long shaping of synaptically connected neuronal circuits as well as the brain connectome thus defining cognitive reserve. Neuroglial homeostatic and protective physiological responses define brain maintenance and resilience, while neuroglia regenerative capabilities are critical for brain compensation in pathology. Targeting neuroglia may represent an untrodden path for prolonging cognitive longevity.
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Affiliation(s)
- Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PT, UK.
- Department of Neurosciences, University of the Basque Country, 48940, Leioa, Bizkaia, Spain.
- IKERBASQUE Basque Foundation for Science, Bilbao, Spain.
- University of Ljubljana, Institute of Pathophysiology, Laboratory of Neuroendocrinology and Molecular Cell Physiology, Zaloška cesta 4, SI-1000, Ljubljana, Slovenia.
- Celica, BIOMEDICAL, Technology Park 24, 1000, Ljubljana, Slovenia.
| | - Robert Zorec
- University of Ljubljana, Institute of Pathophysiology, Laboratory of Neuroendocrinology and Molecular Cell Physiology, Zaloška cesta 4, SI-1000, Ljubljana, Slovenia.
- Celica, BIOMEDICAL, Technology Park 24, 1000, Ljubljana, Slovenia.
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3
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Li X, Shan J, Liu X, Huang Z, Xu G, Ren L. Microglial repopulation induced by PLX3397 protects against ischemic brain injury by suppressing neuroinflammation in aged mice. Int Immunopharmacol 2024; 138:112473. [PMID: 38943977 DOI: 10.1016/j.intimp.2024.112473] [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: 03/27/2024] [Revised: 05/31/2024] [Accepted: 06/10/2024] [Indexed: 07/01/2024]
Abstract
As the resident immune cells in the central nervous system, microglia exhibit a 'sensitized' or 'primed' phenotype with dystrophic morphology and dysregulated functions in aged brains. Although studies have demonstrated the inflammatory profile of aged microglia in several neurological diseases, this issue is largely uncertain in stroke. Consequently, this study investigated the effects of primed and repopulated microglia on post-ischemic brain injury in aged mice. We replaced primed microglia with newly repopulated microglia through pharmacological administration and withdrawal of the colony-stimulating factor 1 receptor (CSF1R) inhibitor, PLX3397. Further, we performed a series of behavioral tests and flow cytometry in mouse models of middle cerebral artery occlusion (MCAO) to study the effects of microglial replacement on ischemic injury in the aged brain. With depletion and subsequent repopulation of microglia in MCAO mice, microglial replacement in aged mice improved neurological function and decreased brain infarction. This protective effect was accompanied by the reduction of peripheral immune cells infiltrating into brains. We showed that the repopulated microglia expressed elevated neuroprotective factors (including Cluster of Differentiation 206, transforming growth factor-β, and interleukin-10) and diminished expression of inflammatory markers (including Cluster of Differentiation 86, interleukin-6, and tumor necrosis factor α). Moreover, microglial replacement protected the blood-brain barrier and relieved neuronal death in aged mice subjected to 60 min of MCAO. These results imply that the replacement of microglia in the aged brain may alleviate brain damage and neuroinflammation, and therefore, ischemic brain damage. Thus, targeting microglia could be a promising therapeutic strategy for ischemic stroke.
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Affiliation(s)
- Xiuping Li
- Department of Neurology, Shenzhen Institute of Translational Medicine, First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen 518060, China; Department of Neurology, First Affiliated Hospital, Shanxi Medical University, Taiyuan 030000, China
| | - Jingyang Shan
- Department of Neurology, Shenzhen Institute of Translational Medicine, First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen 518060, China
| | - Xia Liu
- Department of Neurology, Shenzhen Institute of Translational Medicine, First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen 518060, China
| | - Zhengzheng Huang
- Department of Neurology, Shenzhen Institute of Translational Medicine, First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen 518060, China
| | - Gelin Xu
- Department of Neurology, Shenzhen Institute of Translational Medicine, First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen 518060, China.
| | - Lijie Ren
- Department of Neurology, Shenzhen Institute of Translational Medicine, First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Guangdong Key Laboratory for Biomedical Measurements and Ultrasound Imaging, National-Regional Key Technology Engineering Laboratory for Medical Ultrasound, School of Biomedical Engineering, Shenzhen University Medical School, Shenzhen 518060, China.
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4
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Di Pietro AA, Pasquini LA. A novel in vitro model for investigating oligodendroglial maturation and myelin deposition under demyelinating and remyelinating conditions: Impact of microglial depletion and repopulation. Mol Cell Neurosci 2024; 129:103937. [PMID: 38796120 DOI: 10.1016/j.mcn.2024.103937] [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: 02/26/2024] [Revised: 05/14/2024] [Accepted: 05/17/2024] [Indexed: 05/28/2024] Open
Abstract
Experimental models of multiple sclerosis (MS) have significantly contributed to our understanding of pathophysiology and the development of therapeutic interventions. Various in vivo animal models have successfully replicated key features of MS and associated pathophysiological processes, shedding light on the sequence of events leading to disease initiation, progression, and resolution. Nevertheless, these models often entail substantial costs and prolonged treatment periods. In contrast, in vitro models offer distinct advantages, including cost-effectiveness and precise control over experimental conditions, thereby facilitating more reproducible results. We have developed a novel in vitro model tailored to the study of oligodendroglial maturation and myelin deposition under demyelinating and remyelinating conditions, which encompasses all the cell types present in the central nervous system (CNS). Of note, our model enables the evaluation of microglial cell commitment through a protocol involving their depletion and subsequent repopulation. Given that the development and survival of microglia are critically reliant on colony-stimulating factor-1 receptor (CSF-1R) signaling, we have employed CSF-1R inhibition to effectively deplete microglia. This versatile model holds promise for the assessment of potential therapies aimed at promoting oligodendroglial differentiation to safeguard and repair myelin, hence mitigate neurodegenerative processes.
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Affiliation(s)
- Anabella Ayelen Di Pietro
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Cátedra de Química Biológica Patológica, Buenos Aires, Argentina; Universidad de Buenos Airess, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisicoquímica Biológicas Prof. Dr. Alejandro C. Paladini, Facultad de Farmacia y Bioquímica, Buenos Aire, Argentina.
| | - Laura Andrea Pasquini
- Universidad de Buenos Aires, Facultad de Farmacia y Bioquímica, Departamento de Química Biológica, Cátedra de Química Biológica Patológica, Buenos Aires, Argentina; Universidad de Buenos Airess, Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto de Química y Fisicoquímica Biológicas Prof. Dr. Alejandro C. Paladini, Facultad de Farmacia y Bioquímica, Buenos Aire, Argentina.
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Chen Q, Wu M, Tang Q, Yan P, Zhu L. Age-Related Alterations in Immune Function and Inflammation: Focus on Ischemic Stroke. Aging Dis 2024; 15:1046-1074. [PMID: 37728582 PMCID: PMC11081165 DOI: 10.14336/ad.2023.0721-1] [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: 05/03/2023] [Accepted: 07/21/2023] [Indexed: 09/21/2023] Open
Abstract
The aging of the global population poses significant scientific challenges. Moreover, the biological process of aging is the most significant risk factor for most chronic illnesses; therefore, understanding the molecular and cellular mechanisms underlying these aging-related challenges is crucial for extending the healthy lifespan of older individuals. Preventing brain aging remains a priority public health goal, and integrative and comprehensive aging analyses have revealed that immunosenescence is a potential cause of age-related brain damage and disease (e.g., stroke). Importantly, the neuroinflammatory and immune systems present two-way contact and thus can affect each other. Emerging evidence supports the numerous effects of immunosenescence- and inflammation-mediated immunity in neurologically injured brains. In this study, we briefly outline how aging alters the pathophysiology and transcriptional amplitude in patients who experienced stroke and then discuss how the immune system and its cellular components and molecular mechanisms are affected by age after stroke. Finally, we highlight emerging interventions with the potential to slow down or reduce aging and prevent stroke onset.
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Affiliation(s)
- Qiuxin Chen
- The First Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin 150000, China
| | - Minmin Wu
- Heilongjiang University of Chinese Medicine, Harbin 150000, China
| | - Qiang Tang
- The Second Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin 150000, China
| | - Peiyu Yan
- Faculty of Chinese Medicine, Macau University of Science and Technology, Macau 999078, China
- State Key Laboratory of Quality Research in Chinese Medicines, Macau University of Science and Technology, Macau 999078, China
| | - Luwen Zhu
- The Second Affiliated Hospital of Heilongjiang University of Chinese Medicine, Harbin 150000, China
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Kline-Schoder AR, Chintamen S, Willner MJ, DiBenedetto MR, Noel RL, Batts AJ, Kwon N, Zacharoulis S, Wu CC, Menon V, Kernie SG, Konofagou EE. Characterization of the responses of brain macrophages to focused ultrasound-mediated blood-brain barrier opening. Nat Biomed Eng 2024; 8:650-663. [PMID: 37857722 DOI: 10.1038/s41551-023-01107-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 09/16/2023] [Indexed: 10/21/2023]
Abstract
The opening of the blood-brain barrier (BBB) by focused ultrasound (FUS) coupled with intravenously injected microbubbles can be leveraged as a form of immunotherapy for the treatment of neurodegenerative disorders. However, how FUS BBB opening affects brain macrophages is not well understood. Here by using single-cell sequencing to characterize the distinct responses of microglia and central nervous system-associated macrophages (CAMs) to FUS-mediated BBB opening in mice, we show that the treatment remodels the immune landscape via the recruitment of CAMs and the proliferation of microglia and via population size increases in disease-associated microglia. Both microglia and CAMs showed early and late increases in population sizes, yet only the proliferation of microglia increased at both timepoints. The population of disease-associated microglia also increased, accompanied by the upregulation of genes associated with gliogenesis and phagocytosis, with the depletion of brain macrophages significantly decreasing the duration of BBB opening.
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Affiliation(s)
| | - Sana Chintamen
- Department of Neurobiology and Behaviour, Columbia University, New York, NY, USA
| | - Moshe J Willner
- Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | | | - Rebecca L Noel
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Alec J Batts
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | - Nancy Kwon
- Department of Biomedical Engineering, Columbia University, New York, NY, USA
| | | | - Cheng-Chia Wu
- Department of Pediatrics, Columbia University, New York, NY, USA
| | - Vilas Menon
- Department of Neurology, Columbia University, New York, NY, USA
| | - Steven G Kernie
- Department of Pediatrics, Columbia University, New York, NY, USA
| | - Elisa E Konofagou
- Department of Biomedical Engineering, Columbia University, New York, NY, USA.
- Department of Radiology, Columbia University, New York, NY, USA.
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Stoll AC, Kemp CJ, Patterson JR, Kubik M, Kuhn N, Benskey M, Duffy MF, Luk KC, Sortwell CE. Alpha-synuclein inclusion responsive microglia are resistant to CSF1R inhibition. J Neuroinflammation 2024; 21:108. [PMID: 38664840 PMCID: PMC11045433 DOI: 10.1186/s12974-024-03108-5] [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: 05/03/2023] [Accepted: 04/22/2024] [Indexed: 04/28/2024] Open
Abstract
BACKGROUND Parkinson's disease (PD) is a neurodegenerative disorder that is characterized by the presence of proteinaceous alpha-synuclein (α-syn) inclusions (Lewy bodies), markers of neuroinflammation and the progressive loss of nigrostriatal dopamine (DA) neurons. These pathological features can be recapitulated in vivo using the α-syn preformed fibril (PFF) model of synucleinopathy. We have previously determined that microglia proximal to PFF-induced nigral α-syn inclusions increase in soma size, upregulate major-histocompatibility complex-II (MHC-II) expression, and increase expression of a suite of inflammation-associated transcripts. This microglial response is observed months prior to degeneration, suggesting that microglia reacting to α-syn inclusion may contribute to neurodegeneration and could represent a potential target for novel therapeutics. The goal of this study was to determine whether colony stimulating factor-1 receptor (CSF1R)-mediated microglial depletion impacts the magnitude of α-syn aggregation, nigrostriatal degeneration, or the response of microglial in the context of the α-syn PFF model. METHODS Male Fischer 344 rats were injected intrastriatally with either α-syn PFFs or saline. Rats were continuously administered Pexidartinib (PLX3397B, 600 mg/kg), a CSF1R inhibitor, to deplete microglia for a period of either 2 or 6 months. RESULTS CSF1R inhibition resulted in significant depletion (~ 43%) of ionized calcium-binding adapter molecule 1 immunoreactive (Iba-1ir) microglia within the SNpc. However, CSF1R inhibition did not impact the increase in microglial number, soma size, number of MHC-II immunoreactive microglia or microglial expression of Cd74, Cxcl10, Rt-1a2, Grn, Csf1r, Tyrobp, and Fcer1g associated with phosphorylated α-syn (pSyn) nigral inclusions. Further, accumulation of pSyn and degeneration of nigral neurons was not impacted by CSF1R inhibition. Paradoxically, long term CSF1R inhibition resulted in increased soma size of remaining Iba-1ir microglia in both control and PFF rats, as well as expression of MHC-II in extranigral regions. CONCLUSIONS Collectively, our results suggest that CSF1R inhibition does not impact the microglial response to nigral pSyn inclusions and that CSF1R inhibition is not a viable disease-modifying strategy for PD.
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Affiliation(s)
- Anna C Stoll
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
- Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI, USA
| | - Christopher J Kemp
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
| | - Joseph R Patterson
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
| | - Michael Kubik
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
| | - Nathan Kuhn
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
| | - Matthew Benskey
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
| | - Megan F Duffy
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA
| | - Kelvin C Luk
- Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Caryl E Sortwell
- Department of Translational Neuroscience, Michigan State University, 400 Monroe Ave NW, Grand Rapids, MI, 49503, USA.
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Song Y, Liao Y, Liu T, Chen Y, Wang F, Zhou Z, Zhang W, Li J. Microglial repopulation restricts ocular inflammation and choroidal neovascularization in mice. Front Immunol 2024; 15:1366841. [PMID: 38711521 PMCID: PMC11070532 DOI: 10.3389/fimmu.2024.1366841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Accepted: 04/04/2024] [Indexed: 05/08/2024] Open
Abstract
Introduction Age-related macular degeneration (AMD) is a prevalent, chronic and progressive retinal degenerative disease characterized by an inflammatory response mediated by activated microglia accumulating in the retina. In this study, we demonstrate the therapeutically effects and the underlying mechanisms of microglial repopulation in the laser-induced choroidal neovascularization (CNV) model of exudative AMD. Methods The CSF1R inhibitor PLX3397 was used to establish a treatment paradigm for microglial repopulation in the retina. Neovascular leakage and neovascular area were examined by fundus fluorescein angiography (FFA) and immunostaining of whole-mount RPE-choroid-sclera complexes in CNV mice receiving PLX3397. Altered cellular senescence was measured by beta-galactosidase (SA-β-gal) activity and p16INK4a expression. The effect and mechanisms of repopulated microglia on leukocyte infiltration and the inflammatory response in CNV lesions were analyzed. Results We showed that ten days of the CSF1R inhibitor PLX3397 treatment followed by 11 days of drug withdrawal was sufficient to stimulate rapid repopulation of the retina with new microglia. Microglial repopulation attenuated pathological choroid neovascularization and dampened cellular senescence in CNV lesions. Repopulating microglia exhibited lower levels of activation markers, enhanced phagocytic function and produced fewer cytokines involved in the immune response, thereby ameliorating leukocyte infiltration and attenuating the inflammatory response in CNV lesions. Discussion The microglial repopulation described herein are therefore a promising strategy for restricting inflammation and choroidal neovascularization, which are important players in the pathophysiology of AMD.
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Affiliation(s)
- Yinting Song
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
| | - Yuefeng Liao
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
| | - Tong Liu
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
| | - Yanxian Chen
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
- Experimental Ophthalmology, School of Optometry, The Hong Kong Polytechnic University, HongKong, Hong Kong SAR, China
| | - Fei Wang
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
| | - Zixia Zhou
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
| | - Weili Zhang
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
| | - Jinying Li
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen Peking University-The Hong Kong University of Science and Technology Medical Center, Shenzhen, Guangdong, China
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Tang X, Walter E, Wohleb E, Fan Y, Wang C. ATG5 (autophagy related 5) in microglia controls hippocampal neurogenesis in Alzheimer disease. Autophagy 2024; 20:847-862. [PMID: 37915255 PMCID: PMC11062374 DOI: 10.1080/15548627.2023.2277634] [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: 08/28/2023] [Accepted: 10/26/2023] [Indexed: 11/03/2023] Open
Abstract
Macroautophagy/autophagy is the intracellular degradation process of cytoplasmic content and damaged organelles. Autophagy is strongly associated with the progression of Alzheimer disease (AD). Microglia are brain-resident macrophages, and recent studies indicate that autophagy in microglia protects neurons from neurodegeneration. Postnatal neurogenesis, the generation of new neurons from adult neural stem cells (NSCs), is impaired in AD patients as well as in AD animal models. However, the extent to which microglial autophagy influences adult NSCs and neurogenesis in AD animal models has not been studied. Here, we showed that conditional knock out (cKO) of Atg5 (autophagy related 5) in microglia inhibited postnatal neurogenesis in the dentate gyrus (DG) of the hippocampus, but not in the subventricular zone (SVZ) of a 5×FAD mouse model. Interestingly, the protection of neurogenesis by Atg5 in microglia was only observed in female AD mice. To confirm the roles of autophagy in microglia for postnatal hippocampal neurogenesis, we generated additional cKO mice to delete autophagy essential genes Rb1cc1 or Atg14 in microglia. However, these rb1cc1 cKO and atg14 cKO mice did not exhibit neurogenesis defects in the context of a female AD mouse model. Last, we used the CSF1R antagonist to deplete ATG5-deficient microglia and this intervention restored neurogenesis in the hippocampus of 5×FAD mice. These results indicate that microglial ATG5 is essential to maintain postnatal hippocampal neurogenesis in a mouse model of AD. Our findings further support the notion that ATG5 in microglia supports NSC health and may prevent neurodegeneration.Abbreviations: 5×FAD: familial Alzheimer disease; Aβ: β-amyloid; AD: Alzheimer disease; AIF1: allograft inflammatory factor 1; ATG: autophagy related; BrdU: 5-bromo-2'-deoxyuridine; CA: Cornu Ammonis; cKO: conditional knock out; CSF1R: colony stimulating factor 1 receptor; Ctrl: control; DCX: doublecortin; DG: dentate gyrus; GFAP: glial fibrillary acidic protein; GZ: granular zone; H&E: hematoxylin and eosin; IF: immunofluorescence; LD: lipid droplet; LDAM: lipid droplets accumulated microglia; LPS: lipopolysaccharides; MAP1LC3B/LC3: microtubule-associated protein 1 light chain 3 beta; NSCs: neural stem cells; RB1CC1: RB1-inducible coiled-coil 1; SOX2: SRY (sex determining region Y)-box 2; SGZ: subgranular zone; SVZ: subventricular zone; WT: wild type.
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Affiliation(s)
- Xin Tang
- Department of Cancer Biology, University of Cincinnati College Medicine, Cincinnati, OH, USA
| | - Ellen Walter
- Department of Cancer Biology, University of Cincinnati College Medicine, Cincinnati, OH, USA
| | - Eric Wohleb
- Department of Pharmacology & Systems Physiology, University of Cincinnati College Medicine, Cincinnati, OH, USA
| | - Yanbo Fan
- Department of Cancer Biology, University of Cincinnati College Medicine, Cincinnati, OH, USA
| | - Chenran Wang
- Department of Cancer Biology, University of Cincinnati College Medicine, Cincinnati, OH, USA
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10
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Park SY, Cha N, Kim S, Chae S, Lee WJ, Jung H, Bae H. Blocking Microglial Proliferation by CSF-1R Inhibitor Does Not Alter the Neuroprotective Effects of Adoptive Regulatory T Cells in 3xTg Alzheimer's Disease Mice. Curr Issues Mol Biol 2024; 46:2871-2883. [PMID: 38666910 PMCID: PMC11049167 DOI: 10.3390/cimb46040180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2024] [Revised: 03/19/2024] [Accepted: 03/21/2024] [Indexed: 04/28/2024] Open
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disease that causes cognitive impairment. Neuroinflammation induced by activated microglia exacerbates AD. Regulatory T cells (Tregs) play roles in limiting neuroinflammation by converting microglial polarization. Therefore, adoptive Treg therapy is considered an attractive option for neurodegenerative disorders. However, the mechanism underlying Treg therapy via microglial modulation is not fully understood. In this study, we sought to determine whether adoptively transferred Tregs were effective when microglia proliferation was inhibited by using GW2580, which is an inhibitor of CSF1R. We found that inhibition of microglial proliferation during Treg transfer did not alter the therapeutic effects of Tregs on cognitive deficits and the accumulation of Aβ and pTAU in 3xTg-AD mice. The expression of pro- and anti-inflammatory markers in the hippocampus of 3xTg mice showed that GW2580 did not affect the inhibition of neuroinflammation by Treg transfer. Additionally, adoptively transferred Tregs were commonly detected in the brain on day 7 after transfer and their levels decreased slowly over 100 days. Our findings suggest that adoptively transferred Tregs can survive longer than 100 days in the brain, suppressing microglial activation and thus alleviating AD pathology. The present study provides valuable evidence to support the prolonged efficacy of adoptive Treg therapy in AD.
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Affiliation(s)
- Seon-Young Park
- Department of Science in Korean Medicine, College of Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Nari Cha
- Department of Science in Korean Medicine, College of Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Soyoung Kim
- Department of Science in Korean Medicine, College of Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Songah Chae
- Department of Korean Medicine, College of Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Won-Jun Lee
- Department of Korean Medicine, College of Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Hyunjae Jung
- Department of Korean Medicine, College of Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
| | - Hyunsu Bae
- Department of Science in Korean Medicine, College of Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
- Department of Korean Medicine, College of Korean Medicine, Graduate School, Kyung Hee University, Seoul 02447, Republic of Korea
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11
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Peng S, Wang A, Ding J, Soreq L. Editorial: Bioinformatics analysis of single cell sequencing and multi-omics in the aging and age-associated diseases. Front Aging Neurosci 2024; 16:1384586. [PMID: 38515516 PMCID: PMC10956127 DOI: 10.3389/fnagi.2024.1384586] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Accepted: 02/12/2024] [Indexed: 03/23/2024] Open
Affiliation(s)
- Shouneng Peng
- Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY, United States
| | - Ailan Wang
- Beijing Hotgen Biotech Co., Ltd., Beijing, China
| | - Junjun Ding
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, China
| | - Lilach Soreq
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London, United Kingdom
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12
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Zhuge F, Zheng L, Pan Y, Ni L, Fu Z, Shi J, Ni Y. DPP-4 inhibition by linagliptin ameliorates age-related mild cognitive impairment by regulating microglia polarization in mice. Exp Neurol 2024; 373:114689. [PMID: 38199510 DOI: 10.1016/j.expneurol.2024.114689] [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: 10/23/2023] [Revised: 12/29/2023] [Accepted: 01/06/2024] [Indexed: 01/12/2024]
Abstract
Extensive preclinical evidence demonstrates a causative link between insulin signaling dysfunction and the pathogenesis of Alzheimer's disease (AD), and diabetic drugs may represent a promising approach to fighting AD. However, it remains to be determined which antidiabetic drugs are more effective in preventing cognitive impairment. Thus, the present study investigated the effect of dipeptidyl peptidase-4 (DPP-4) inhibitor linagliptin on cognitive impairment in middle-aged mice by comparing it with the effect of metformin. We found that DPP-4 activity increased in the hippocampus of middle-aged mice, and DPP-4 was mainly expressed by microglia rather than astrocytes and oligodendrocytes. DPP-4 directly regulated M1/M2 microglia polarization following LPS or IL-4 stimulation, while DPP-4 inhibitor, linagliptin, suppressed M1-polarized activation and induced M2-polarized activation. Both linagliptin and metformin enhanced cognitive ability, increased hippocampal synaptic plasticity and neurogenesis, and decreased age-related oxidative stress and inflammation by regulating microglia polarization in the hippocampus of middle-aged mice. The combination of linagliptin and metformin showed a maximum protective effect compared to the individual drugs alone. Loss of macrophage inflammatory protein-1α (MIP-1α), a DPP-4 substrate, abrogated the cognitive protection and anti-inflammation effects of linagliptin. Therefore, the current investigation exhibits a potential utility for DPP-4 inhibition in attenuating microglia-mediated inflammation and preventing mild cognitive impairment (MCI) in middle-aged mice, and the effect was partly mediated by MIP-1α.
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Affiliation(s)
- Fen Zhuge
- Institute of Translational Medicine, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Liujie Zheng
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Yuxiang Pan
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Liyang Ni
- Food Biochemistry Laboratory, Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo, Japan
| | - Zhengwei Fu
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Junping Shi
- Department of Infectious Disease, The Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Yinhua Ni
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China.
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13
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Fan H, Zhang M, Wen J, Wang S, Yuan M, Sun H, Shu L, Yang X, Pu Y, Cai Z. Microglia in brain aging: An overview of recent basic science and clinical research developments. J Biomed Res 2024; 38:122-136. [PMID: 38403286 PMCID: PMC11001587 DOI: 10.7555/jbr.37.20220220] [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: 10/05/2022] [Revised: 12/25/2022] [Accepted: 01/12/2023] [Indexed: 02/27/2024] Open
Abstract
Aging is characterized by progressive degeneration of tissues and organs, and it is positively associated with an increased mortality rate. The brain, as one of the most significantly affected organs, experiences age-related changes, including abnormal neuronal activity, dysfunctional calcium homeostasis, dysregulated mitochondrial function, and increased levels of reactive oxygen species. These changes collectively contribute to cognitive deterioration. Aging is also a key risk factor for neurodegenerative diseases, such as Alzheimer's disease and Parkinson's disease. For many years, neurodegenerative disease investigations have primarily focused on neurons, with less attention given to microglial cells. However, recently, microglial homeostasis has emerged as an important mediator in neurological disease pathogenesis. Here, we provide an overview of brain aging from the perspective of the microglia. In doing so, we present the current knowledge on the correlation between brain aging and the microglia, summarize recent progress of investigations about the microglia in normal aging, Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis, and then discuss the correlation between the senescent microglia and the brain, which will culminate with a presentation of the molecular complexity involved in the microglia in brain aging with suggestions for healthy aging.
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Affiliation(s)
- Haixia Fan
- Chongqing Medical University, Chongqing 400042, China
- Department of Neurology, Chongqing General Hospital, Chongqing 400013, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing 400013, China
- Department of Neurology, the First Hospital of Shanxi Medical University, Taiyuan, Shanxi 030001, China
| | - Minheng Zhang
- Department of Gerontology, the First People's Hospital of Jinzhong, Jinzhong, Shanxi 030009, China
| | - Jie Wen
- Chongqing Medical University, Chongqing 400042, China
- Department of Neurology, Chongqing General Hospital, Chongqing 400013, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing 400013, China
| | - Shengyuan Wang
- Chongqing Medical University, Chongqing 400042, China
- Department of Neurology, Chongqing General Hospital, Chongqing 400013, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing 400013, China
| | - Minghao Yuan
- Chongqing Medical University, Chongqing 400042, China
- Department of Neurology, Chongqing General Hospital, Chongqing 400013, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing 400013, China
| | - Houchao Sun
- Department of Neurology, Chongqing General Hospital, Chongqing 400013, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing 400013, China
| | - Liu Shu
- Chongqing Medical University, Chongqing 400042, China
- Department of Neurology, Chongqing General Hospital, Chongqing 400013, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing 400013, China
| | - Xu Yang
- Chongqing Medical University, Chongqing 400042, China
- Department of Neurology, Chongqing General Hospital, Chongqing 400013, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing 400013, China
| | - Yinshuang Pu
- Department of Neurology, Chongqing General Hospital, Chongqing 400013, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing 400013, China
| | - Zhiyou Cai
- Chongqing Medical University, Chongqing 400042, China
- Department of Neurology, Chongqing General Hospital, Chongqing 400013, China
- Chongqing Key Laboratory of Neurodegenerative Diseases, Chongqing 400013, China
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14
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Saito K, Shigetomi E, Shinozaki Y, Kobayashi K, Parajuli B, Kubota Y, Sakai K, Miyakawa M, Horiuchi H, Nabekura J, Koizumi S. Microglia sense astrocyte dysfunction and prevent disease progression in an Alexander disease model. Brain 2024; 147:698-716. [PMID: 37955589 PMCID: PMC10834242 DOI: 10.1093/brain/awad358] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 09/28/2023] [Accepted: 10/06/2023] [Indexed: 11/14/2023] Open
Abstract
Alexander disease (AxD) is an intractable neurodegenerative disorder caused by GFAP mutations. It is a primary astrocyte disease with a pathological hallmark of Rosenthal fibres within astrocytes. AxD astrocytes show several abnormal phenotypes. Our previous study showed that AxD astrocytes in model mice exhibit aberrant Ca2+ signals that induce AxD aetiology. Here, we show that microglia have unique phenotypes with morphological and functional alterations, which are related to the pathogenesis of AxD. Immunohistochemical studies of 60TM mice (AxD model) showed that AxD microglia exhibited highly ramified morphology. Functional changes in microglia were assessed by Ca2+ imaging using hippocampal brain slices from Iba1-GCaMP6-60TM mice and two-photon microscopy. We found that AxD microglia showed aberrant Ca2+ signals, with high frequency Ca2+ signals in both the processes and cell bodies. These microglial Ca2+ signals were inhibited by pharmacological blockade or genetic knockdown of P2Y12 receptors but not by tetrodotoxin, indicating that these signals are independent of neuronal activity but dependent on extracellular ATP from non-neuronal cells. Our single-cell RNA sequencing data showed that the expression level of Entpd2, an astrocyte-specific gene encoding the ATP-degrading enzyme NTPDase2, was lower in AxD astrocytes than in wild-type astrocytes. In situ ATP imaging using the adeno-associated virus vector GfaABC1D ATP1.0 showed that exogenously applied ATP was present longer in 60TM mice than in wild-type mice. Thus, the increased ATP level caused by the decrease in its metabolizing enzyme in astrocytes could be responsible for the enhancement of microglial Ca2+ signals. To determine whether these P2Y12 receptor-mediated Ca2+ signals in AxD microglia play a significant role in the pathological mechanism, a P2Y12 receptor antagonist, clopidogrel, was administered. Clopidogrel significantly exacerbated pathological markers in AxD model mice and attenuated the morphological features of microglia, suggesting that microglia play a protective role against AxD pathology via P2Y12 receptors. Taken together, we demonstrated that microglia sense AxD astrocyte dysfunction via P2Y12 receptors as an increase in extracellular ATP and alter their morphology and Ca2+ signalling, thereby protecting against AxD pathology. Although AxD is a primary astrocyte disease, our study may facilitate understanding of the role of microglia as a disease modifier, which may contribute to the clinical diversity of AxD.
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Affiliation(s)
- Kozo Saito
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan
- GLIA Center, University of Yamanashi, Yamanashi 409-3898, Japan
| | - Eiji Shigetomi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan
- GLIA Center, University of Yamanashi, Yamanashi 409-3898, Japan
| | - Youichi Shinozaki
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan
- GLIA Center, University of Yamanashi, Yamanashi 409-3898, Japan
| | - Kenji Kobayashi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan
| | - Bijay Parajuli
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan
- GLIA Center, University of Yamanashi, Yamanashi 409-3898, Japan
| | - Yuto Kubota
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan
| | - Kent Sakai
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan
- GLIA Center, University of Yamanashi, Yamanashi 409-3898, Japan
| | - Miho Miyakawa
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan
- GLIA Center, University of Yamanashi, Yamanashi 409-3898, Japan
| | - Hiroshi Horiuchi
- Division of Homeostatic Development, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Aichi 444-8585, Japan
| | - Junichi Nabekura
- Division of Homeostatic Development, National Institute for Physiological Sciences, National Institutes of Natural Sciences, Aichi 444-8585, Japan
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, Yamanashi 409-3898, Japan
- GLIA Center, University of Yamanashi, Yamanashi 409-3898, Japan
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15
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Chintamen S, Gaur P, Vo N, Bradshaw EM, Menon V, Kernie SG. Distinct microglial transcriptomic signatures within the hippocampus. PLoS One 2024; 19:e0296280. [PMID: 38180982 PMCID: PMC10775894 DOI: 10.1371/journal.pone.0296280] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2023] [Accepted: 12/08/2023] [Indexed: 01/07/2024] Open
Abstract
Microglia, the resident immune cells of the brain, are crucial in the development of the nervous system. Recent evidence demonstrates that microglia modulate adult hippocampal neurogenesis by inhibiting cell proliferation of neural precursors and survival both in vitro and in vivo, thus maintaining a balance between cell division and cell death in the neural stem cell pool. There are increasing reports suggesting these microglia found in neurogenic niches differ from their counterparts in non-neurogenic areas. Here, we present evidence that hippocampal microglia exhibit transcriptomic heterogeneity, with some cells expressing genes associated with neurogenesis. By comprehensively profiling myeloid lineage cells in the hippocampus using single cell RNA-sequencing, we have uncovered a small, yet distinct population of microglia which exhibit depletion in genes associated with homeostatic microglia and enrichment of genes associated with phagocytosis. Intriguingly, this population also expresses a gene signature with substantial overlap with previously characterized phenotypes, including disease associated microglia (DAM), a particularly unique and compelling microglial state.
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Affiliation(s)
- Sana Chintamen
- Department of Pediatrics, Columbia University College of Physicians and
Surgeons, New York, New York, United States of America
| | - Pallavi Gaur
- Department of Neurology, Columbia University College of Physicians and
Surgeons, New York, New York, United States of America
| | - Nicole Vo
- Department of Neurology, Columbia University College of Physicians and
Surgeons, New York, New York, United States of America
| | - Elizabeth M. Bradshaw
- Department of Neurology, Columbia University College of Physicians and
Surgeons, New York, New York, United States of America
| | - Vilas Menon
- Department of Neurology, Columbia University College of Physicians and
Surgeons, New York, New York, United States of America
| | - Steven G. Kernie
- Department of Pediatrics, Columbia University College of Physicians and
Surgeons, New York, New York, United States of America
- Department of Neurology, Columbia University College of Physicians and
Surgeons, New York, New York, United States of America
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16
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Kim JD, Copperi F, Diano S. Microglia in Central Control of Metabolism. Physiology (Bethesda) 2024; 39:0. [PMID: 37962895 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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17
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Heuer SE, Keezer KJ, Hewes AA, Onos KD, Graham KC, Howell GR, Bloss EB. Control of hippocampal synaptic plasticity by microglia-dendrite interactions depends on genetic context in mouse models of Alzheimer's disease. Alzheimers Dement 2024; 20:601-614. [PMID: 37753835 PMCID: PMC10840883 DOI: 10.1002/alz.13440] [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: 05/19/2023] [Revised: 07/28/2023] [Accepted: 08/01/2023] [Indexed: 09/28/2023]
Abstract
INTRODUCTION Human data suggest susceptibility and resilience to features of Alzheimer's disease (AD) such as microglia activation and synaptic dysfunction are under genetic control. However, causal relationships between these processes, and how genomic diversity modulates them remain systemically underexplored in mouse models. METHODS AD-vulnerable hippocampal neurons were virally labeled in inbred (C57BL/6J) and wild-derived (PWK/PhJ) APP/PS1 and wild-type mice, and brain microglia depleted from 4 to 8 months of age. Dendrites were assessed for synapse plasticity changes by evaluating spine densities and morphologies. RESULTS In C57BL/6J, microglia depletion blocked amyloid-induced synaptic density and morphology changes. At a finer scale, synaptic morphology on individual branches was dependent on microglia-dendrite physical interactions. Conversely, synapses from PWK/PhJ mice showed remarkable stability in response to amyloid, and no evidence of microglia contact-dependent changes on dendrites. DISCUSSION These results demonstrate that microglia-dependent synaptic alterations in specific AD-vulnerable projection pathways are differentially controlled by genetic context.
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Affiliation(s)
- Sarah E. Heuer
- The Jackson LaboratoryBar HarborMaineUSA
- Graduate School of Biomedical SciencesTufts UniversityBostonMassachusettsUSA
| | | | | | | | | | - Gareth R. Howell
- The Jackson LaboratoryBar HarborMaineUSA
- Graduate School of Biomedical SciencesTufts UniversityBostonMassachusettsUSA
- Graduate School of Biomedical Sciences and EngineeringUniversity of MaineOronoMaineUSA
| | - Erik B. Bloss
- The Jackson LaboratoryBar HarborMaineUSA
- Graduate School of Biomedical SciencesTufts UniversityBostonMassachusettsUSA
- Graduate School of Biomedical Sciences and EngineeringUniversity of MaineOronoMaineUSA
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18
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Castro R, Lopes M, De Biase L, Valdez G. Aging spinal cord microglia become phenotypically heterogeneous and preferentially target motor neurons and their synapses. Glia 2024; 72:206-221. [PMID: 37737058 PMCID: PMC10773989 DOI: 10.1002/glia.24470] [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: 06/01/2023] [Revised: 08/07/2023] [Accepted: 09/03/2023] [Indexed: 09/23/2023]
Abstract
Microglia have been found to acquire unique region-dependent deleterious features with age and diseases that contribute to neuronal dysfunction and degeneration in the brain. However, it remains unknown whether microglia exhibit similar phenotypic heterogeneity in the spinal cord. Here, we performed a regional analysis of spinal cord microglia in 3-, 16-, 23-, and 30-month-old mice. Using light and electron microscopy, we discovered that spinal cord microglia acquire an increasingly activated phenotype during the course of aging regardless of regional location. However, aging causes microglia in the ventral but not dorsal horn to lose their spatial organization. Aged ventral horn microglia also aggregate around the somata of motor neurons and increase their contacts with motor synapses, which have been shown to be lost with age. These findings suggest that microglia may affect the ability of motor neurons to receive and relay motor commands during aging. To generate additional insights about aging spinal cord microglia, we performed RNA-sequencing on FACS-isolated microglia from 3-, 18-, 22-, and 29-month-old mice. We found that spinal cord microglia acquire a similar transcriptional identity as those in the brain during aging that includes altered expression of genes with roles in microglia-neuron interactions and inflammation. By 29 months of age, spinal cord microglia exhibit additional and unique transcriptional changes known and predicted to cause senescence and to alter lysosomal and ribosomal regulation. Altogether, this work provides the foundation to target microglia to ameliorate aged-related changes in the spinal cord, and particularly on the motor circuit.
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Affiliation(s)
- Ryan Castro
- Neuroscience Graduate Program, Brown University, Providence, Rhode Island, USA
| | - Mikayla Lopes
- Molecular Biology, Cell Biology & Biochemistry Graduate Program, Brown University, Providence, Rhode Island, USA
| | - Lindsay De Biase
- Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, USA
| | - Gregorio Valdez
- Department of Molecular Biology, Cell Biology and Biochemistry, Brown University, Providence, Rhode Island, USA
- Center for Translational Neuroscience, Robert J. and Nancy D. Carney Institute for Brain Science and Brown Institute for Translational Science, Brown University, Providence, Rhode Island, USA
- Department of Neurology, Warren Alpert Medical School of Medicine, Brown University, Providence, USA
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19
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Liu J, van Beusekom H, Bu X, Chen G, Henrique Rosado de Castro P, Chen X, Chen X, Clarkson AN, Farr TD, Fu Y, Jia J, Jolkkonen J, Kim WS, Korhonen P, Li S, Liang Y, Liu G, Liu G, Liu Y, Malm T, Mao X, Oliveira JM, Modo MM, Ramos‐Cabrer P, Ruscher K, Song W, Wang J, Wang X, Wang Y, Wu H, Xiong L, Yang Y, Ye K, Yu J, Zhou X, Zille M, Masters CL, Walczak P, Boltze J, Ji X, Wang Y. Preserving cognitive function in patients with Alzheimer's disease: The Alzheimer's disease neuroprotection research initiative (ADNRI). NEUROPROTECTION 2023; 1:84-98. [PMID: 38223913 PMCID: PMC10783281 DOI: 10.1002/nep3.23] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 08/07/2023] [Accepted: 08/08/2023] [Indexed: 01/16/2024]
Abstract
The global trend toward aging populations has resulted in an increase in the occurrence of Alzheimer's disease (AD) and associated socioeconomic burdens. Abnormal metabolism of amyloid-β (Aβ) has been proposed as a significant pathomechanism in AD, supported by results of recent clinical trials using anti-Aβ antibodies. Nonetheless, the cognitive benefits of the current treatments are limited. The etiology of AD is multifactorial, encompassing Aβ and tau accumulation, neuroinflammation, demyelination, vascular dysfunction, and comorbidities, which collectively lead to widespread neurodegeneration in the brain and cognitive impairment. Hence, solely removing Aβ from the brain may be insufficient to combat neurodegeneration and preserve cognition. To attain effective treatment for AD, it is necessary to (1) conduct extensive research on various mechanisms that cause neurodegeneration, including advances in neuroimaging techniques for earlier detection and a more precise characterization of molecular events at scales ranging from cellular to the full system level; (2) identify neuroprotective intervention targets against different neurodegeneration mechanisms; and (3) discover novel and optimal combinations of neuroprotective intervention strategies to maintain cognitive function in AD patients. The Alzheimer's Disease Neuroprotection Research Initiative's objective is to facilitate coordinated, multidisciplinary efforts to develop systemic neuroprotective strategies to combat AD. The aim is to achieve mitigation of the full spectrum of pathological processes underlying AD, with the goal of halting or even reversing cognitive decline.
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Affiliation(s)
- Jie Liu
- Department of Neurology, Daping HospitalThird Military Medical UniversityChongqingChina
- Chongqing Key Laboratory of Ageing and Brain DiseasesChongqingChina
| | - Heleen van Beusekom
- Division of Experimental Cardiology, Department of Cardiology, Erasmus MCUniversity Medical CenterRotterdamThe Netherlands
| | - Xian‐Le Bu
- Department of Neurology, Daping HospitalThird Military Medical UniversityChongqingChina
- Chongqing Key Laboratory of Ageing and Brain DiseasesChongqingChina
- Institute of Brain and IntelligenceThird Military Medical UniversityChongqingChina
| | - Gong Chen
- Guangdong‐HongKong‐Macau Institute of CNS Regeneration (GHMICR)Jinan UniversityGuangzhouGuangdongChina
| | | | - Xiaochun Chen
- Fujian Key Laboratory of Molecular Neurology, Department of Neurology and Geriatrics, Fujian Institute of Geriatrics, Fujian Medical University Union Hospital, Institute of NeuroscienceFujian Medical UniversityFuzhouFujianChina
| | - Xiaowei Chen
- Institute of Brain and IntelligenceThird Military Medical UniversityChongqingChina
- Guangyang Bay LaboratoryChongqing Institute for Brain and IntelligenceChongqingChina
- Center for Excellence in Brain Science and Intelligence TechnologyChinese Academy of SciencesShanghaiChina
| | - Andrew N. Clarkson
- Department of Anatomy, Brain Health Research Centre and Brain Research New ZealandUniversity of OtagoDunedinNew Zealand
| | - Tracy D. Farr
- School of Life SciencesUniversity of NottinghamNottinghamUK
| | - Yuhong Fu
- Brain and Mind Centre & School of Medical SciencesThe University of SydneySydneyNew South WalesAustralia
| | - Jianping Jia
- Innovation Center for Neurological Disorders and Department of Neurology, Xuanwu Hospital, National Clinical Research Center for Geriatric DiseasesCapital Medical UniversityBeijingChina
| | - Jukka Jolkkonen
- A.I. Virtanen Institute for Molecular SciencesUniversity of Eastern FinlandKuopioFinland
| | - Woojin Scott Kim
- Brain and Mind Centre & School of Medical SciencesThe University of SydneySydneyNew South WalesAustralia
| | - Paula Korhonen
- A.I. Virtanen Institute for Molecular SciencesUniversity of Eastern FinlandKuopioFinland
| | - Shen Li
- Department of Neurology and Psychiatry, Beijing Shijitan HospitalCapital Medical UniversityBeijingChina
| | - Yajie Liang
- Department of Diagnostic Radiology and Nuclear MedicineUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | - Guang‐Hui Liu
- University of Chinese Academy of SciencesBeijingChina
- State Key Laboratory of Membrane Biology, Institute of ZoologyChinese Academy of SciencesBeijingChina
| | - Guiyou Liu
- Beijing Institute of Brain Disorders, Laboratory of Brain Disorders, Ministry of Science and Technology, Collaborative Innovation Center for Brain DisordersCapital Medical UniversityBeijingChina
| | - Yu‐Hui Liu
- Department of Neurology, Daping HospitalThird Military Medical UniversityChongqingChina
- Chongqing Key Laboratory of Ageing and Brain DiseasesChongqingChina
- Institute of Brain and IntelligenceThird Military Medical UniversityChongqingChina
| | - Tarja Malm
- A.I. Virtanen Institute for Molecular SciencesUniversity of Eastern FinlandKuopioFinland
| | - Xiaobo Mao
- Institute for Cell Engineering, Department of NeurologyThe Johns Hopkins University School of MedicineBaltimoreMarylandUSA
| | - Joaquim Miguel Oliveira
- 3B's Research Group, I3Bs—Research Institute on Biomaterials, Biodegradables and Biomimetics, Headquarters of the European Institute of Excellence on Tissue Engineering and Regenerative MedicineUniversity of MinhoGuimarãesPortugal
- ICVS/3B's—PT Government Associate LaboratoryBraga/GuimarãesPortugal
| | - Mike M. Modo
- Department of Bioengineering, McGowan Institute for Regenerative MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
- Department of Radiology, McGowan Institute for Regenerative MedicineUniversity of PittsburghPittsburghPennsylvaniaUSA
| | - Pedro Ramos‐Cabrer
- Magnetic Resonance Imaging LaboratoryCIC BiomaGUNE Research Center, Basque Research and Technology Alliance (BRTA)Donostia‐San SebastianSpain
| | - Karsten Ruscher
- Laboratory for Experimental Brain Research, Division of Neurosurgery, Department of Clinical SciencesLund UniversityLundSweden
| | - Weihong Song
- Institute of Aging, Key Laboratory of Alzheimer's Disease of Zhejiang Province. Zhejiang Clinical Research Center for Mental Disorders, School of Mental Health and The Affiliated Kangning Hospital, Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health)Wenzhou Medical UniversityZhejiangChina
| | - Jun Wang
- Department of Neurology, Daping HospitalThird Military Medical UniversityChongqingChina
- Chongqing Key Laboratory of Ageing and Brain DiseasesChongqingChina
| | - Xuanyue Wang
- School of Optometry and Vision ScienceUniversity of New South WalesSydneyNew South WalesAustralia
| | - Yun Wang
- Neuroscience Research Institute, Department of Neurobiology, School of Basic, Medical Sciences, Key Laboratory for Neuroscience, Ministry of Education/National, Health Commission and State Key Laboratory of Natural and Biomimetic DrugsPeking UniversityBeijingChina
- PKU‐IDG/McGovern Institute for Brain ResearchPeking UniversityBeijingChina
| | - Haitao Wu
- Department of NeurobiologyBeijing Institute of Basic Medical SciencesBeijingChina
| | - Lize Xiong
- Shanghai Key Laboratory of Anesthesiology and Brain Functional Modulation, Clinical Research Center for Anesthesiology and Perioperative Medicine, Translational Research Institute of Brain and Brain‐Like Intelligence, Shanghai Fourth People's Hospital, School of MedicineTongji UniversityShanghaiChina
| | - Yi Yang
- Department of NeurologyThe First Hospital of Jilin University, Chang ChunJilinChina
| | - Keqiang Ye
- Faculty of Life and Health SciencesBrain Cognition and Brain Disease Institute (BCBDI), Shenzhen Institute of Advanced TechnologyShenzhenChina
| | - Jin‐Tai Yu
- State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Department of Neurology and Institute of Neurology, Huashan Hospital, Shanghai Medical CollegeFudan UniversityShanghaiChina
| | - Xin‐Fu Zhou
- Division of Health Sciences, School of Pharmacy and Medical Sciences and Sansom InstituteUniversity of South AustraliaAdelaideSouth AustraliaAustralia
- Suzhou Auzone BiotechSuzhouJiangsuChina
| | - Marietta Zille
- Department of Pharmaceutical Sciences, Division of Pharmacology and ToxicologyUniversity of ViennaViennaAustria
| | - Colin L. Masters
- The Florey InstituteThe University of Melbourne, ParkvilleVictoriaAustralia
| | - Piotr Walczak
- Department of Diagnostic Radiology and Nuclear MedicineUniversity of Maryland School of MedicineBaltimoreMarylandUSA
| | | | - Xunming Ji
- Department of NeurosurgeryXuanwu Hospital, Capital Medical UniversityBeijingChina
| | - Yan‐Jiang Wang
- Department of Neurology, Daping HospitalThird Military Medical UniversityChongqingChina
- Chongqing Key Laboratory of Ageing and Brain DiseasesChongqingChina
- Institute of Brain and IntelligenceThird Military Medical UniversityChongqingChina
- Guangyang Bay LaboratoryChongqing Institute for Brain and IntelligenceChongqingChina
- Center for Excellence in Brain Science and Intelligence TechnologyChinese Academy of SciencesShanghaiChina
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20
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Kong W, Xie Z, Shang X, Hayashi Y, Lan F, Narengaowa, Zhao S, Li H, Quan Z, Wu Z, Nakanishi H, Qing H, Ni J. Zinc finger protein 335 mediates lipopolysaccharide-induced neurodegeneration and memory loss as a transcriptional factor in microglia. Glia 2023; 71:2720-2734. [PMID: 37522284 DOI: 10.1002/glia.24447] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 05/06/2023] [Accepted: 05/22/2023] [Indexed: 08/01/2023]
Abstract
Zinc finger protein 335 (Zfp335) is a transcription factor that regulates mammalian neurogenesis and neuronal differentiation. It is a causative factor for severe microcephaly, small somatic size, and neonatal death. Here, we evaluated the effects of Zfp335 in the adult mouse brain after lipopolysaccharide (LPS) challenge. We used wild-type (WT) and Zfp335 knock-down (Zfp335+/- ) mice with LPS administered in the intracerebral ventricle in vivo and cultured microglia treated with LPS in vitro. The impact of Zfp335 was evaluated by RT-PCR, RNA-sequencing, western blotting, immunocytochemistry, ELISA, and the memory behavior tests. Knockdown of Zfp335 expression ameliorated microglia activation significantly, including reduced mRNA and protein expression of Iba1, reduced numbers of microglia, reduced cell diameter, and increased branch length, in the brains of 2-month-old mice after LPS treatment. Zfp335 was expressed in microglia and neurons, but increased in microglia, not neurons, in the brain of mice after LPS administration. LPS-induced microglia-mediated neurodegeneration was dependent upon microglial Zfp335 controlled by nuclear factor-kappa B. Microglial Zfp335 affected neuronal activity through transcriptional regulation of lymphocyte antigen-6M (Ly6M). Our data suggest that Zfp335 is a key transcription factor that exacerbates microglia-mediated neurodegeneration through upregulation of Ly6M expression. Inhibition of microglial Zfp335 may be a new strategy for preventing brain disease induced by microglia activation.
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Affiliation(s)
- Wei Kong
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Zhen Xie
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Xiaokang Shang
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Yoshinori Hayashi
- Department of Physiology, Nihon University School of Dentistry, Chiyoda-ku, Tokyo, Japan
| | - Fei Lan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Narengaowa
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Shuxuan Zhao
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Hui Li
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Zhenzhen Quan
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Zhou Wu
- Department of Aging Science and Pharmacology, 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
| | - Hong Qing
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
| | - Junjun Ni
- Key Laboratory of Molecular Medicine and Biotherapy, School of Life Science, Beijing Institute of Technology, Beijing, China
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21
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Dong L, Jiang N, Bai J, Li Y, Song Z, Liu X, Zhang C. Neuroprotective Effects of Dammarane Sapogenins Against lipopolysaccharide-induced Cognitive Impairment, Neuroinflammation and Synaptic Dysfunction. Neurochem Res 2023; 48:3525-3537. [PMID: 37490197 DOI: 10.1007/s11064-023-03997-7] [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: 02/23/2023] [Revised: 04/11/2023] [Accepted: 07/15/2023] [Indexed: 07/26/2023]
Abstract
Neuroinflammation is a critical driver in the pathogenesis and progression of neurodegenerative disorders. Dammarane sapogenins (DS), a deglycosylated product of ginsenoside, possess a variety of potent biological activities. The present study aimed to explore the neuroprotective effects of DS in a rat model of neuroinflammation induced by intracerebroventricular injection of lipopolysaccharide (LPS). Our study revealed that DS pretreatment effectively improved LPS-induced associative learning and memory impairments in the active avoidance response test and spatial learning and memory in Morris water maze test. DS also remarkably inhibited LPS-induced neuroinflammation by suppressing microglia overactivation, pro-inflammatory cytok ine release (TNF-α and IL-1β) and reducing neuronal loss in the CA1 and DG regions of the hippocampus. Importantly, pretreatment with DS reversed LPS-induced upregulation of HMGB1 and TLR4 and inhibited their downstream NF-κB signaling activation, as evidenced by increased IκBα and decreased p-NF-κB p65 levels. Furthermore, DS ameliorated LPS-induced synaptic dysfunction by decreasing MMP-9 and increasing NMDAR1 expression in the hippocampus. Taken together, this study suggests that DS could be a promising treatment for preventing cognitive impairments caused by neuroinflammation.
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Affiliation(s)
- Liming Dong
- Department of Pharmacy, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
- Research Center for Pharmacology & Toxicology, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Ning Jiang
- Research Center for Pharmacology & Toxicology, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Jie Bai
- Department of Pharmacy, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Yiman Li
- Department of Pharmacy, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Zhihui Song
- Department of Pharmacy, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Xinmin Liu
- Research Center for Pharmacology & Toxicology, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| | - Chao Zhang
- Department of Pharmacy, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
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22
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Mein N, von Stackelberg N, Wickel J, Geis C, Chung HY. Low-dose PLX5622 treatment prevents neuroinflammatory and neurocognitive sequelae after sepsis. J Neuroinflammation 2023; 20:289. [PMID: 38041192 PMCID: PMC10691003 DOI: 10.1186/s12974-023-02975-8] [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: 07/09/2023] [Accepted: 11/28/2023] [Indexed: 12/03/2023] Open
Abstract
BACKGROUND Sepsis-associated encephalopathy (SAE) is characterized by symptoms of delirium including hallucinations, impaired concentration, agitation, or coma and is associated with poor outcome in the early phase of sepsis. In addition, sepsis survivors often suffer from persisting memory deficits and impaired executive functions. Recent studies provide evidence that microglia are involved in the pathophysiology of SAE. METHODS Here, we investigated whether pharmacological depletion of microglia using PLX5622 (1200 ppm or 300 ppm) in the acute phase of sepsis is able to prevent long-term neurocognitive decline in a male mouse model of polymicrobial sepsis or lipopolysaccharide-induced sterile neuroinflammation. Therefore, we performed the novel object recognition test at different time points after sepsis to address hippocampus-dependent learning. To further assess synapse engulfment in microglia, colocalization analysis was performed using high-resolution 3D Airyscan imaging of Iba1 and Homer1. We also investigated the effect of PLX5622 on acute astrocyte and chronic microglia proliferation in the hippocampus after sepsis induction using immunofluorescence staining. RESULTS High-dose application of the colony stimulating factor 1 receptor (CSF1R) inhibitor PLX5622 (1200 ppm) seven days prior to sepsis induction lead to 70-80% microglia reduction but resulted in fatal outcome of bacterial sepsis or LPS induced inflammation. This is likely caused by severely compromised host immune response upon PLX5622-induced depletion of peripheral monocytes and macrophages. We therefore tested partial microglia depletion using a low-dose of PLX5622 (300 ppm) for seven days prior to sepsis which resulted in an increased survival in comparison to littermates subjected to high-dose CSF1R inhibiton and to a stable microglia reduction of ~ 40%. This partial microglia depletion in the acute stage of sepsis largely prevented the engulfment and microglia-induced stripping of postsynaptic terminals. In addition, PLX5622 low-dose microglia depletion attenuated acute astrogliosis as well as long-term microgliosis and prevented long-term neurocognitive decline after experimental sepsis. CONCLUSIONS We conclude that partial microglia depletion before the induction of sepsis may be sufficient to attenuate long-term neurocognitive dysfunction. Application of PLX5622 (300 ppm) acts by reducing microglia-induced synaptic attachement/engulfment and preventing chronic microgliosis.
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Affiliation(s)
- Nils Mein
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
| | - Nikolai von Stackelberg
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
| | - Jonathan Wickel
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
- Center for Sepsis Control and Care, Jena University Hospital, 07747, Jena, Germany
| | - Christian Geis
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany
- Center for Sepsis Control and Care, Jena University Hospital, 07747, Jena, Germany
- German Center for Mental Health, Center for Intervention and Research on Adaptive and Maladaptive Brain Circuits Underlying Mental Health (C-I-R-C), Jena-Magdeburg-Halle, Germany
| | - Ha-Yeun Chung
- Section of Translational Neuroimmunology, Department of Neurology, Jena University Hospital, Am Klinikum 1, 07747, Jena, Germany.
- Center for Sepsis Control and Care, Jena University Hospital, 07747, Jena, Germany.
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23
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Shi Y, Stowe AM, Hu X. The role of immune cells in brain injuries and diseases. Neurobiol Dis 2023; 188:106340. [PMID: 37913833 DOI: 10.1016/j.nbd.2023.106340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2023] Open
Affiliation(s)
- Yejie Shi
- Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
| | - Ann M Stowe
- Department of Neurology, College of Medicine, University of Kentucky, Lexington, KY, USA.
| | - Xiaoming Hu
- Department of Neurology, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA.
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24
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Carver CM, Gomez PT, Rodriguez SL, Kachergus JM, Liu Y, Shi J, Tran T, Wang L, Melov S, Thompson EA, Schafer MJ. Senescent and disease-associated microglia are modifiable features of aged brain white matter. RESEARCH SQUARE 2023:rs.3.rs-3467812. [PMID: 37961365 PMCID: PMC10635389 DOI: 10.21203/rs.3.rs-3467812/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
Brain white matter tracts undergo structural and functional changes linked to late-life cognitive decline, but the cellular and molecular contributions to their selective vulnerability are not well defined. In naturally aged mice, we demonstrate that senescent and disease-associated microglia (DAM) phenotypes converge in hippocampus-adjacent white matter. Through gold-standard gene expression and immunolabeling combined with high-dimensional spatial mapping, we identified microglial cell fates in aged white matter characterized by aberrant morphology, microenvironment reorganization, and expression of senescence and DAM markers, including galectin 3 (GAL3/Lgals3), B-cell lymphoma 2 (Bcl2), and cyclin dependent kinase inhibitors, including Cdkn2a/p16ink4a. Pharmacogenetic or pharmacological targeting of p16ink4a or BCL2 reduced white matter GAL3+ DAM abundance and rejuvenated microglial fimbria organization. Our results demonstrate dynamic changes in microglial identity in aged white matter that can be reverted by senotherapeutic intervention to promote homeostatic maintenance in the aged brain.
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Affiliation(s)
- Chase M. Carver
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - Paul T. Gomez
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | - Sonia L. Rodriguez
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
| | | | - Yi Liu
- Department of Quantitative Health Sciences, Mayo Clinic, Jacksonville, FL, USA
| | - Ji Shi
- Department of Cancer Biology, Mayo Clinic, Jacksonville, FL, USA
| | - Tommy Tran
- Buck Institute for Research on Aging, Novato, CA, USA
| | - Liguo Wang
- Division of Computational Biology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Simon Melov
- Buck Institute for Research on Aging, Novato, CA, USA
| | | | - Marissa J. Schafer
- Department of Physiology and Biomedical Engineering, Mayo Clinic, Rochester, MN, USA
- Robert and Arlene Kogod Center on Aging, Mayo Clinic, Rochester, MN, USA
- Department of Neurology, Mayo Clinic, Rochester, MN, USA
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25
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Soreq L, Mohamed W. Single-cell RNA sequencing analysis and Alzheimer's disease: a bibliometric analysis. AMERICAN JOURNAL OF NEURODEGENERATIVE DISEASE 2023; 12:133-146. [PMID: 38024391 PMCID: PMC10658177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Accepted: 10/22/2023] [Indexed: 12/01/2023]
Abstract
Alzheimer's disease (AD) is a devastative disease, the 1st most frequent neurodegenerative disease worldwide. Its prevalence is increasing and early detection methods as well as potential genomic based therapeutics are urgently needed. OBJECTIVES To better characterize recent seq studies of AD and site recent relevant literature. Using single-cell RNA sequencing, the characteristics of neuronal cell populations in Alzheimer's disease (AD) have not been completely elucidated. METHODS We conducted a dynamic and longitudinal bibliometric analysis to investigate existing studies on Single-cell RNA sequencing analysis and Alzheimer's Disease and identify data gaps and possible new research avenues. RESULTS All AD papers concentrating on Single-cell RNA sequencing analysis were found using the search terms "Alzheimer's Disease", and "Single-cell RNA sequencing analysis" in the PubMed/MEDLINE database. Only English publications published between 2015 and 2023 were chosen using filters. CONCLUSIONS Original English-language research publications disclosing Single-cell RNA sequencing analysis and Alzheimer's Disease were examined for inclusion. Two sets of independent reviewers discovered and extracted pertinent data. The bibliometric study was carried out using the R software packages Bibliometrix and Biblioshiny. The narrowed search yielded 158 publications, all published between 2015 and 2023. Yet, after applying filters and considering the inclusion requirements, the search results comprise just 51 original articles out of 158 articles. There were 107 articles eliminated. The importance of the discovery of Single-cell RNA sequencing analysis and Alzheimer's Disease a decade ago only grows with time. Our results have important implications for future studies of AD and may help researchers across the world better understand the global context of the Single-cell RNA sequencing analysis and Alzheimer's Disease link. This study puts emphasis on the critical need for more diverse participant demographics in Alzheimer's disease investigations.
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Affiliation(s)
| | - Wael Mohamed
- Basic Medical Science Department, Kulliyyah of Medicine, International Islamic University MalaysiaKuantan, Pahang 25200, Malaysia
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26
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Okojie AK, Uweru JO, Coburn MA, Li S, Cao-Dao VD, Eyo UB. Distinguishing the effects of systemic CSF1R inhibition by PLX3397 on microglia and peripheral immune cells. J Neuroinflammation 2023; 20:242. [PMID: 37865779 PMCID: PMC10590528 DOI: 10.1186/s12974-023-02924-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 10/10/2023] [Indexed: 10/23/2023] Open
Abstract
Microglia, the primary immune cells of the central nervous system (CNS), are derived from the yolk sac and populate the brain during development. Once microglia migrate to the CNS, they are self-renewing and require CSF1R signaling for their maintenance. Pexidartinib (PLX3397, PLX), a small molecule inhibitor of the CSF1R, has been shown to effectively deplete microglia since microglial maintenance is CSF1R-dependent. There have, however, been several conflicting reports that have shown the potential off-target effects of PLX on peripheral immune cells particularly those of lymphoid origin. Given this controversy in the use of the PLX family of drugs, it has become important to ascertain to what extent PLX affects the peripheral immune profile in lymphoid (spleen, and bone marrow) and non-lymphoid (kidney, lungs, and heart) organs. PLX3397 chow treatment at 660 mg/kg for 7 days significantly reduced CD45+ macrophages, CX3CR1-GFP cells, CD11b+CD45intermediate cells, and P2RY12 expression in the brain. However, there were minimal effects on peripheral immune cells from both lymphoid and non-lymphoid organs except in the heart where there was a significant decrease in CD3+ cells, inflammatory and patrolling monocytes, and CD11b+Ly6G+ neutrophils. We then stimulated the immune system with 1 mg/kg of LPS which resulted in a significant reduction in the number of innate immune cells. In this context, PLX did not alter the cytokine profile in the serum and the brain of naïve mice but did so in the LPS-stimulated group resulting in a significant reduction in TNFα, IL-1α, IFN-γ and IL-1β. Furthermore, PLX did not alter locomotor activity in the open field test suggesting that microglia do not contribute to LPS-induced sickness behavior. Our results provide an assessment of immune cell populations with PLX3397 treatment on brain, lymphoid and non-lymphoid organs without and during LPS treatment that can serve as a resource for understanding consequences of such approaches.
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Affiliation(s)
- Akhabue K Okojie
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA.
- Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, USA.
| | - Joseph O Uweru
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
- Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Morgan A Coburn
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
- Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Sihan Li
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Vivian D Cao-Dao
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
- Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Ukpong B Eyo
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA.
- Center for Brain Immunology and Glia, University of Virginia School of Medicine, Charlottesville, VA, USA.
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27
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Wang W, Li Y, Ma F, Sheng X, Chen K, Zhuo R, Wang C, Zheng H, Zhang YW, Bu G, Chen XF, Zhong L. Microglial repopulation reverses cognitive and synaptic deficits in an Alzheimer's disease model by restoring BDNF signaling. Brain Behav Immun 2023; 113:275-288. [PMID: 37482204 DOI: 10.1016/j.bbi.2023.07.011] [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: 02/02/2023] [Revised: 07/10/2023] [Accepted: 07/20/2023] [Indexed: 07/25/2023] Open
Abstract
Over the past decade, compelling genetic evidence has highlighted the crucial role of microglial dysregulation in the development of Alzheimer's disease (AD). As resident immune cells in the brain, microglia undergo dystrophy and senescence during the chronic progression of AD. To explore the potential therapeutic benefits of replenishing the brain with new microglia in AD, we utilized the CSF1R inhibitor PLX3397 to deplete existing microglia and induce repopulation after inhibitor withdrawal in 5xFAD transgenic mice. Our findings revealed the remarkable benefits of microglial repopulation in ameliorating AD-associated cognitive deficits, accompanied by a notable elevation in synaptic proteins and an enhancement of hippocampal long-term potentiation (LTP). Additionally, we observed the profound restoration of microglial morphology and synaptic engulfment following their self-renewal. The impact of microglial repopulation on amyloid pathology is dependent on the duration of repopulation. Transcriptome analysis revealed a high resemblance between the gene expression profiles of repopulated microglia from 5xFAD mice and those of microglia from WT mice. Importantly, the dysregulated neurotrophic signaling pathway and hippocampal neurogenesis in the AD brain are restored following microglial replenishment. Lastly, we demonstrated that the repopulation restores the expression of brain-derived neurotrophic factor (BDNF) in microglia, thereby contributing to synaptic plasticity. In conclusion, our findings provide compelling evidence to support the notion that microglial self-renewal confers substantial benefits to the AD brain by restoring the BDNF neurotrophic signaling pathway. Thus, targeted microglial repopulation emerges as a highly promising and novel therapeutic strategy for alleviating cognitive impairment in AD.
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Affiliation(s)
- Wanbing Wang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen 361102, China
| | - Yanzhong Li
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen 361102, China
| | - Fangling Ma
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen 361102, China
| | - Xuan Sheng
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen 361102, China
| | - Kai Chen
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen 361102, China
| | - Rengong Zhuo
- Xiamen Key Laboratory of Chiral Drugs, School of Medicine, Xiamen University, Xiamen 361102, China
| | - Chen Wang
- Department of Neurology, The First Affiliated Hospital, School of Medicine, Xiamen University, Xiamen 361003, China
| | - Honghua Zheng
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen 361102, China
| | - Yun-Wu Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen 361102, China
| | - Guojun Bu
- Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224, USA
| | - Xiao-Fen Chen
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen 361102, China; Shenzhen Research Institute of Xiamen University, Shenzhen 518063, China.
| | - Li Zhong
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen 361102, China.
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28
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Yan L, Xuan FL, Chen S, Gou M, Chen W, Li Y, Wang Z, Wang L, Xie T, Fan F, Zharkovsky A, Tan Y, Tian L. Replenished microglia partially rescue schizophrenia-related stress response. Front Cell Neurosci 2023; 17:1254923. [PMID: 37771931 PMCID: PMC10522857 DOI: 10.3389/fncel.2023.1254923] [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: 07/07/2023] [Accepted: 08/15/2023] [Indexed: 09/30/2023] Open
Abstract
Background Microglia play an important role in the maintenance of brain and behavioral homeostasis. The protective effect of microglial replenishment was reported in neurological diseases, but whether microglial therapy would benefit psychiatric disorders such as schizophrenia has been unclear. As schizophrenia is a stress-vulnerable disorder and psychosocial stress promotes inflammation and microglial activation, we aim to understand how microglial replenishment works in stress-associated schizophrenia. Methods We used a CSF1R-mediated pharmacological approach to study repopulated microglia (repMg) in a cohort of mice (n = 10/group) undergoing chronic unpredictable stress (CUS). We further studied a cohort of first-episode schizophrenia (FES, n = 74) patients who had higher perceived stress scores (PSS) than healthy controls (HCs, n = 68). Results Reborn microglia attenuated CUS-induced learned hopelessness and social withdrawal but not anxiety in mice. Compared to control, CUS- or repMg-induced differentially expressed genes (DEGs) in the prefrontal cortex regulated nervous system development and axonal guidance. CUS also caused microglial hyper-ramification and increased engulfment of synaptophysin and vesicular glutamate transporter-2 by microglia and astrocytes, which were recovered in CUS + repMg (all p < 0.05). Moreover, FES patients had smaller hippocampal fimbria than HCs (p < 1e-7), which were negatively associated with PSS (r = -0.397, p = 0.003). Blood DEGs involved in immune system development were also associated with PSS and the right fimbria more prominently in FES patients than HCs (Zr, p < 0.0001). The KCNQ1 was a partial mediator between PSS and fimbria size (β = -0.442, 95% CI: -1.326 ~ -0.087). Conclusion Microglial replenishment may potentially benefit psychiatric disorders such as schizophrenia.
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Affiliation(s)
- Ling Yan
- Institute of Biomedicine and Translational Medicine, Faculty of Medicine, University of Tartu, Tartu, Estonia
| | - Fang-Ling Xuan
- Institute of Biomedicine and Translational Medicine, Faculty of Medicine, University of Tartu, Tartu, Estonia
| | - Song Chen
- Psychiatry Research Centre, Beijing Huilongguan Hospital, Peking University Health Science Center, Beijing, China
| | - Mengzhuang Gou
- Psychiatry Research Centre, Beijing Huilongguan Hospital, Peking University Health Science Center, Beijing, China
| | - Wenjin Chen
- Psychiatry Research Centre, Beijing Huilongguan Hospital, Peking University Health Science Center, Beijing, China
| | - Yanli Li
- Psychiatry Research Centre, Beijing Huilongguan Hospital, Peking University Health Science Center, Beijing, China
| | - Zhiren Wang
- Psychiatry Research Centre, Beijing Huilongguan Hospital, Peking University Health Science Center, Beijing, China
| | - Leilei Wang
- Psychiatry Research Centre, Beijing Huilongguan Hospital, Peking University Health Science Center, Beijing, China
| | - Ting Xie
- Psychiatry Research Centre, Beijing Huilongguan Hospital, Peking University Health Science Center, Beijing, China
| | - Fengmei Fan
- Psychiatry Research Centre, Beijing Huilongguan Hospital, Peking University Health Science Center, Beijing, China
| | - Alexander Zharkovsky
- Institute of Biomedicine and Translational Medicine, Faculty of Medicine, University of Tartu, Tartu, Estonia
| | - Yunlong Tan
- Psychiatry Research Centre, Beijing Huilongguan Hospital, Peking University Health Science Center, Beijing, China
| | - Li Tian
- Institute of Biomedicine and Translational Medicine, Faculty of Medicine, University of Tartu, Tartu, Estonia
- Psychiatry Research Centre, Beijing Huilongguan Hospital, Peking University Health Science Center, Beijing, China
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Weiß EM, Geldermann M, Martini R, Klein D. Macrophages influence Schwann cell myelin autophagy after nerve injury and in a model of Charcot-Marie-Tooth disease. J Peripher Nerv Syst 2023; 28:341-350. [PMID: 37209383 DOI: 10.1111/jns.12561] [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: 03/07/2023] [Revised: 05/04/2023] [Accepted: 05/15/2023] [Indexed: 05/22/2023]
Abstract
BACKGROUND AND AIMS The complex cellular and molecular interactions between Schwann cells (SCs) and macrophages during Wallerian degeneration are a prerequisite to allow rapid uptake and degradation of myelin debris and axonal regeneration after peripheral nerve injury. In contrast, in non-injured nerves of Charcot-Marie-Tooth 1 neuropathies, aberrant macrophage activation by SCs carrying myelin gene defects is a disease amplifier that drives nerve damage and subsequent functional decline. Consequently, targeting nerve macrophages might be a translatable treatment strategy to mitigate disease outcome in CMT1 patients. Indeed, in previous approaches, macrophage targeting alleviated the axonopathy and promoted sprouting of damaged fibers. Surprisingly, this was still accompanied by robust myelinopathy in a model for CMT1X, suggesting additional cellular mechanisms of myelin degradation in mutant peripheral nerves. We here investigated the possibility of an increased SC-related myelin autophagy upon macrophage targeting in Cx32def mice. METHODS Combining ex vivo and in vivo approaches, macrophages were targeted by PLX5622 treatment. SC autophagy was investigated by immunohistochemical and electron microscopical techniques. RESULTS We demonstrate a robust upregulation of markers for SC autophagy after injury and in genetically-mediated neuropathy when nerve macrophages are pharmacologically depleted. Corroborating these findings, we provide ultrastructural evidence for increased SC myelin autophagy upon treatment in vivo. INTERPRETATION These findings reveal a novel communication and interaction between SCs and macrophages. This identification of alternative pathways of myelin degradation may have important implications for a better understanding of therapeutic mechanisms of pharmacological macrophage targeting in diseased peripheral nerves.
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Affiliation(s)
- Eva Maria Weiß
- Department of Neurology, Developmental Neurobiology, University Hospital Würzburg, Würzburg, Germany
| | - Miriam Geldermann
- Department of Neurology, Developmental Neurobiology, University Hospital Würzburg, Würzburg, Germany
| | - Rudolf Martini
- Department of Neurology, Developmental Neurobiology, University Hospital Würzburg, Würzburg, Germany
| | - Dennis Klein
- Department of Neurology, Developmental Neurobiology, University Hospital Würzburg, Würzburg, Germany
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Bhatia TN, Jamenis AS, Abbas M, Clark RN, Miner KM, Chandwani MN, Kim RE, Hilinski W, O'Donnell LA, Luk KC, Shi Y, Hu X, Chen J, Brodsky JL, Leak RK. A 14-day pulse of PLX5622 modifies α-synucleinopathy in preformed fibril-infused aged mice of both sexes. Neurobiol Dis 2023; 184:106196. [PMID: 37315905 PMCID: PMC10528721 DOI: 10.1016/j.nbd.2023.106196] [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: 12/01/2022] [Revised: 05/16/2023] [Accepted: 06/07/2023] [Indexed: 06/16/2023] Open
Abstract
Reactive microglia are observed with aging and in Lewy body disorders, including within the olfactory bulb of men with Parkinson's disease. However, the functional impact of microglia in these disorders is still debated. Resetting these reactive cells by a brief dietary pulse of the colony-stimulating factor 1 receptor (CSF1R) inhibitor PLX5622 may hold therapeutic potential against Lewy-related pathologies. To our knowledge, withdrawal of PLX5622 after short-term exposure has not been tested in the preformed α-synuclein fibril (PFF) model, including in aged mice of both sexes. Compared to aged female mice, we report that aged males on the control diet showed higher numbers of phosphorylated α-synuclein+ inclusions in the limbic rhinencephalon after PFFs were injected in the posterior olfactory bulb. However, aged females displayed larger inclusion sizes compared to males. Short-term (14-day) dietary exposure to PLX5622 followed by control chow reduced inclusion numbers and levels of insoluble α-synuclein in aged males-but not females-and unexpectedly raised inclusion sizes in both sexes. Transient delivery of PLX5622 also improved spatial reference memory in PFF-infused aged mice, as evidenced by an increase in novel arm entries in a Y-maze. Superior memory was positively correlated with inclusion sizes but negatively correlated with inclusion numbers. Although we caution that PLX5622 delivery must be tested further in models of α-synucleinopathy, our data suggest that larger-sized-but fewer-α-synucleinopathic structures are associated with better neurological outcomes in PFF-infused aged mice.
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Affiliation(s)
- Tarun N Bhatia
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA
| | - Anuj S Jamenis
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA
| | - Muslim Abbas
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA
| | - Rachel N Clark
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA
| | - Kristin M Miner
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA
| | - Manisha N Chandwani
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA
| | - Roxanne E Kim
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA
| | | | - Lauren A O'Donnell
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA
| | - Kelvin C Luk
- Dept. of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Yejie Shi
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA, USA; Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Xiaoming Hu
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA, USA; Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jun Chen
- Geriatric Research, Education and Clinical Center, Veterans Affairs Pittsburgh Health Care System, Pittsburgh, PA, USA; Pittsburgh Institute of Brain Disorders & Recovery and Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Jeffrey L Brodsky
- Dept. of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, USA
| | - Rehana K Leak
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA, USA.
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31
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Nguyen JN, Chauhan A. Bystanders or not? Microglia and lymphocytes in aging and stroke. Neural Regen Res 2023; 18:1397-1403. [PMID: 36571333 PMCID: PMC10075112 DOI: 10.4103/1673-5374.360345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
As the average age of the world population increases, more people will face debilitating aging-associated conditions, including dementia and stroke. Not only does the incidence of these conditions increase with age, but the recovery afterward is often worse in older patients. Researchers and health professionals must unveil and understand the factors behind age-associated diseases to develop a therapy for older patients. Aging causes profound changes in the immune system including the activation of microglia in the brain. Activated microglia promote T lymphocyte transmigration leading to an increase in neuroinflammation, white matter damage, and cognitive impairment in both older humans and rodents. The presence of T and B lymphocytes is observed in the aged brain and correlates with worse stroke outcomes. Preclinical strategies in stroke target either microglia or the lymphocytes or the communications between them to promote functional recovery in aged subjects. In this review, we examine the role of the microglia and T and B lymphocytes in aging and how they contribute to cognitive impairment. Additionally, we provide an important update on the contribution of these cells and their interactions in preclinical aged stroke.
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Affiliation(s)
- Justin N Nguyen
- University of Texas McGovern Medical School at Houston, Houston, TX, USA
| | - Anjali Chauhan
- Department of Neurology, University of Texas McGovern Medical School at Houston, Houston, TX, USA
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32
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Gibbs-Shelton S, Benderoth J, Gaykema RP, Straub J, Okojie KA, Uweru JO, Lentferink DH, Rajbanshi B, Cowan MN, Patel B, Campos-Salazar AB, Perez-Reyes E, Eyo UB. Microglia play beneficial roles in multiple experimental seizure models. Glia 2023; 71:1699-1714. [PMID: 36951238 DOI: 10.1002/glia.24364] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2022] [Revised: 03/09/2023] [Accepted: 03/10/2023] [Indexed: 03/24/2023]
Abstract
Seizure disorders are common, affecting both the young and the old. Currently available antiseizure drugs are ineffective in a third of patients and have been developed with a focus on known neurocentric mechanisms, raising the need for investigations into alternative and complementary mechanisms that contribute to seizure generation or its containment. Neuroinflammation, broadly defined as the activation of immune cells and molecules in the central nervous system (CNS), has been proposed to facilitate seizure generation, although the specific cells involved in these processes remain inadequately understood. The role of microglia, the primary inflammation-competent cells of the brain, is debated since previous studies were conducted using approaches that were less specific to microglia or had inherent confounds. Using a selective approach to target microglia without such side effects, we show a broadly beneficial role for microglia in limiting chemoconvulsive, electrical, and hyperthermic seizures and argue for a further understanding of microglial contributions to contain seizures.
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Affiliation(s)
- Synphane Gibbs-Shelton
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, Virginia, USA
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Jordan Benderoth
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, Virginia, USA
- Department of Neuroscience, University of Virginia, Charlottesville, Virginia, USA
| | - Ronald P Gaykema
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Justyna Straub
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Kenneth A Okojie
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, Virginia, USA
- Department of Neuroscience, University of Virginia, Charlottesville, Virginia, USA
| | - Joseph O Uweru
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, Virginia, USA
- Department of Neuroscience, University of Virginia, Charlottesville, Virginia, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA
| | - Dennis H Lentferink
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, Virginia, USA
- Department of Neuroscience, University of Virginia, Charlottesville, Virginia, USA
| | - Binita Rajbanshi
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Maureen N Cowan
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, Virginia, USA
- Department of Neuroscience, University of Virginia, Charlottesville, Virginia, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA
| | - Brij Patel
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, Virginia, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA
| | - Anthony Brayan Campos-Salazar
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, Virginia, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA
| | - Edward Perez-Reyes
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Ukpong B Eyo
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, Virginia, USA
- Department of Neuroscience, University of Virginia, Charlottesville, Virginia, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA
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Matsudaira T, Nakano S, Konishi Y, Kawamoto S, Uemura K, Kondo T, Sakurai K, Ozawa T, Hikida T, Komine O, Yamanaka K, Fujita Y, Yamashita T, Matsumoto T, Hara E. Cellular senescence in white matter microglia is induced during ageing in mice and exacerbates the neuroinflammatory phenotype. Commun Biol 2023; 6:665. [PMID: 37353538 PMCID: PMC10290132 DOI: 10.1038/s42003-023-05027-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 06/07/2023] [Indexed: 06/25/2023] Open
Abstract
Cellular senescence, a state of irreversible cell-cycle arrest caused by a variety of cellular stresses, is critically involved in age-related tissue dysfunction in various organs. However, the features of cells in the central nervous system that undergo senescence and their role in neural impairment are not well understood as yet. Here, through comprehensive investigations utilising single-cell transcriptome analysis and various mouse models, we show that microglia, particularly in the white matter, undergo cellular senescence in the brain and spinal cord during ageing and in disease models involving demyelination. Microglial senescence is predominantly detected in disease-associated microglia, which appear in ageing and neurodegenerative diseases. We also find that commensal bacteria promote the accumulation of senescent microglia and disease-associated microglia during ageing. Furthermore, knockout of p16INK4a, a key senescence inducer, ameliorates the neuroinflammatory phenotype in damaged spinal cords in mice. These results advance our understanding of the role of cellular senescence in the central nervous system and open up possibilities for the treatment of age-related neural disorders.
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Affiliation(s)
- Tatsuyuki Matsudaira
- Research Institute for Microbial Diseases (RIMD), Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
| | - Sosuke Nakano
- Research Institute for Microbial Diseases (RIMD), Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Yusuke Konishi
- Research Institute for Microbial Diseases (RIMD), Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Shimpei Kawamoto
- Research Institute for Microbial Diseases (RIMD), Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Ken Uemura
- Research Institute for Microbial Diseases (RIMD), Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Tamae Kondo
- Research Institute for Microbial Diseases (RIMD), Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Koki Sakurai
- Laboratory for Advanced Brain Functions, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Takaaki Ozawa
- Laboratory for Advanced Brain Functions, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Takatoshi Hikida
- Laboratory for Advanced Brain Functions, Institute for Protein Research, Osaka University, 3-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Okiru Komine
- Department of Neuroscience and Pathobiology, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Koji Yamanaka
- Department of Neuroscience and Pathobiology, Research Institute of Environmental Medicine, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, 464-8601, Japan
| | - Yuki Fujita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Toshihide Yamashita
- Department of Molecular Neuroscience, Graduate School of Medicine, Osaka University, 2-2 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Tomonori Matsumoto
- Research Institute for Microbial Diseases (RIMD), Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan
| | - Eiji Hara
- Research Institute for Microbial Diseases (RIMD), Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
- Immunology Frontier Research Center (IFReC), Osaka University, 3-1 Yamadaoka, Suita, Osaka, 565-0871, Japan.
- Center for Infectious Diseases Education and Research (CiDER), Osaka University, 2-8 Yamadaoka, Suita, Osaka, 565-0871, Japan.
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Brown FN, Iwasawa E, Shula C, Fugate EM, Lindquist DM, Mangano FT, Goto J. Early postnatal microglial ablation in the Ccdc39 mouse model reveals adverse effects on brain development and in neonatal hydrocephalus. Fluids Barriers CNS 2023; 20:42. [PMID: 37296418 DOI: 10.1186/s12987-023-00433-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 04/19/2023] [Indexed: 06/12/2023] Open
Abstract
BACKGROUND Neonatal hydrocephalus is a congenital abnormality resulting in an inflammatory response and microglial cell activation both clinically and in animal models. Previously, we reported a mutation in a motile cilia gene, Ccdc39 that develops neonatal progressive hydrocephalus (prh) with inflammatory microglia. We discovered significantly increased amoeboid-shaped activated microglia in periventricular white matter edema, reduced mature homeostatic microglia in grey matter, and reduced myelination in the prh model. Recently, the role of microglia in animal models of adult brain disorders was examined using cell type-specific ablation by colony-stimulating factor-1 receptor (CSF1R) inhibitor, however, little information exists regarding the role of microglia in neonatal brain disorders such as hydrocephalus. Therefore, we aim to see if ablating pro-inflammatory microglia, and thus suppressing the inflammatory response, in a neonatal hydrocephalic mouse line could have beneficial effects. METHODS In this study, Plexxikon 5622 (PLX5622), a CSF1R inhibitor, was subcutaneously administered to wild-type (WT) and prh mutant mice daily from postnatal day (P) 3 to P7. MRI-estimated brain volume was compared with untreated WT and prh mutants P7-9 and immunohistochemistry of the brain sections was performed at P8 and P18-21. RESULTS PLX5622 injections successfully ablated IBA1-positive microglia in both the WT and prh mutants at P8. Of the microglia that are resistant to PLX5622 treatment, there was a higher percentage of amoeboid-shaped microglia, identified by morphology with retracted processes. In PLX-treated prh mutants, there was increased ventriculomegaly and no change in the total brain volume was observed. Also, the PLX5622 treatment significantly reduced myelination in WT mice at P8, although this was recovered after full microglia repopulation by P20. Microglia repopulation in the mutants worsened hypomyelination at P20. CONCLUSIONS Microglia ablation in the neonatal hydrocephalic brain does not improve white matter edema, and actually worsens ventricular enlargement and hypomyelination, suggesting critical functions of homeostatic ramified microglia to better improve brain development with neonatal hydrocephalus. Future studies with detailed examination of microglial development and status may provide a clarification of the need for microglia in neonatal brain development.
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Affiliation(s)
- Farrah N Brown
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Eri Iwasawa
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Crystal Shula
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Elizabeth M Fugate
- Department of Radiology, Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Diana M Lindquist
- Department of Radiology, Imaging Research Center, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
| | - Francesco T Mangano
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA
| | - June Goto
- Division of Pediatric Neurosurgery, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
- Department of Neurosurgery, University of Cincinnati College of Medicine, Cincinnati, OH, USA.
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Melchiorri D, Merlo S, Micallef B, Borg JJ, Dráfi F. Alzheimer's disease and neuroinflammation: will new drugs in clinical trials pave the way to a multi-target therapy? Front Pharmacol 2023; 14:1196413. [PMID: 37332353 PMCID: PMC10272781 DOI: 10.3389/fphar.2023.1196413] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Accepted: 05/02/2023] [Indexed: 06/20/2023] Open
Abstract
Despite extensive research, no disease-modifying therapeutic option, able to prevent, cure or halt the progression of Alzheimer's disease [AD], is currently available. AD, a devastating neurodegenerative pathology leading to dementia and death, is characterized by two pathological hallmarks, the extracellular deposits of amyloid beta (Aβ) and the intraneuronal deposits of neurofibrillary tangles (NFTs) consisting of altered hyperphosphorylated tau protein. Both have been widely studied and pharmacologically targeted for many years, without significant therapeutic results. In 2022, positive data on two monoclonal antibodies targeting Aβ, donanemab and lecanemab, followed by the 2023 FDA accelerated approval of lecanemab and the publication of the final results of the phase III Clarity AD study, have strengthened the hypothesis of a causal role of Aβ in the pathogenesis of AD. However, the magnitude of the clinical effect elicited by the two drugs is limited, suggesting that additional pathological mechanisms may contribute to the disease. Cumulative studies have shown inflammation as one of the main contributors to the pathogenesis of AD, leading to the recognition of a specific role of neuroinflammation synergic with the Aβ and NFTs cascades. The present review provides an overview of the investigational drugs targeting neuroinflammation that are currently in clinical trials. Moreover, their mechanisms of action, their positioning in the pathological cascade of events that occur in the brain throughout AD disease and their potential benefit/limitation in the therapeutic strategy in AD are discussed and highlighted as well. In addition, the latest patent requests for inflammation-targeting therapeutics to be developed in AD will also be discussed.
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Affiliation(s)
- Daniela Melchiorri
- Department of Physiology and Pharmacology, Sapienza University, Rome, Italy
| | - Sara Merlo
- Department of Biomedical and Biotechnological Sciences, Section of Pharmacology, University of Catania, Catania, Italy
| | | | - John-Joseph Borg
- Malta Medicines Authority, San Ġwann, Malta
- School of Pharmacy, Department of Biology, University of Tor Vergata, Rome, Italy
| | - František Dráfi
- Institute of Experimental Pharmacology and Toxicology, Centre of Experimental Medicine SAS Bratislava, Bratislava, Slovakia
- State Institute for Drug Control, Bratislava, Slovakia
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Wang X, Xie Y, Niu Y, Wan B, Lu Y, Luo Q, Zhu L. CX3CL1/CX3CR1 signal mediates M1-type microglia and accelerates high-altitude-induced forgetting. Front Cell Neurosci 2023; 17:1189348. [PMID: 37234914 PMCID: PMC10206058 DOI: 10.3389/fncel.2023.1189348] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2023] [Accepted: 04/24/2023] [Indexed: 05/28/2023] Open
Abstract
Introduction Hypoxia-induced neuronal damage is the primary cause of cognitive impairment induced by high-altitude exposure. Microglia play a crucial regulatory role in the central nervous system (CNS) homeostasis and synaptic plasticity. M1-type polarized microglia are suspected to be responsible for CNS injury under hypoxic conditions, but the exact molecular mechanism is still unelucidated. Methods CX3CR1 knock out and wide type mice were exposed to a simulated plateau at 7000 m for 48 h to construct the model of hypobaric hypoxia-induced memory impairment. The memory impairment of mice was assessed by Morris water maze. The dendritic spine density in the hippocampus was examined by Golgi staining. The synapses in the CA1 region and the number of neurons in the DG region were examined by immunofluorescence staining. The synapses in microglia activation and phagocytosis were examined by immunofluorescence. The levels of CX3CL1/CX3CR1 and their downstream proteins were detected. CX3CR1 knockout primary microglia were treated with CX3CL1 combined with 1% O2. The levels of proteins related to microglial polarization, the uptake of synaptosome and phagocytotic ability of microglia were detected. Results In this study, mice exposed to a simulated 7000 m altitude for 48 h developed significant amnesia for recent memories, but no significant change in their anxiety levels was observed. Hypobaric hypoxia exposure (7000 m altitude above sea level for 48 h) resulted in synapse loss in the CA1 region of the hippocampus, but no significant changes occurred in the total number of neurons. Meanwhile, microglia activation, increased phagocytosis of synapses by microglia, and CX3CL1/CX3CR1 signal activation were observed under hypobaric hypoxic exposure. Further, we found that after hypobaric hypoxia exposure, CX3CR1-deficient mice showed less amnesia, less synaptic loss in the CA1 region, and less increase in M1 microglia, compared to their wildtype siblings. CX3CR1-deficient microglia did not exhibit M1-type polarization in response to either hypoxia or CX3CL1 induction. Both hypoxia and CX3CL1 induced the phagocytosis of synapses by microglia through the upregulation of microglial phagocytosis. Discussion The current study demonstrates that CX3CL1/CX3CR1 signal mediates the M1-type polarization of microglia under high-altitude exposure and upregulates microglial phagocytosis, which increases the phagocytosis of synapses in the CA1 region of the hippocampus, causing synaptic loss and inducing forgetting.
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Heuer SE, Keezer KJ, Hewes AA, Onos KD, Graham KC, Howell GR, Bloss EB. Genetic context controls early microglia-synaptic interactions in mouse models of Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.04.28.538728. [PMID: 37162819 PMCID: PMC10168315 DOI: 10.1101/2023.04.28.538728] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Common features of Alzheimer's disease (AD) include amyloid pathology, microglia activation and synaptic dysfunction, however, the causal relationships amongst them remains unclear. Further, human data suggest susceptibility and resilience to AD neuropathology is controlled by genetic context, a factor underexplored in mouse models. To this end, we leveraged viral strategies to label an AD-vulnerable neuronal circuit in CA1 dendrites projecting to the frontal cortex in genetically diverse C57BL/6J (B6) and PWK/PhJ (PWK) APP/PS1 mouse strains and used PLX5622 to non-invasively deplete brain microglia. Reconstructions of labeled neurons revealed microglia-dependent changes in dendritic spine density and morphology in B6 wild-type (WT) and APP/PS1 yet a marked stability of spines across PWK mice. We further showed that synaptic changes depend on direct microglia-dendrite interactions in B6. APP/PS1 but not PWK. APP/PS1 mice. Collectively, these results demonstrate that microglia-dependent synaptic alterations in a specific AD-vulnerable projection pathway are differentially controlled by genetic context.
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Affiliation(s)
- Sarah E. Heuer
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
- Tufts University Graduate School of Biomedical Sciences, Boston, MA 02111, USA
| | | | | | | | | | - Gareth R. Howell
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
- Tufts University Graduate School of Biomedical Sciences, Boston, MA 02111, USA
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, USA
| | - Erik B. Bloss
- The Jackson Laboratory, Bar Harbor, ME 04609, USA
- Tufts University Graduate School of Biomedical Sciences, Boston, MA 02111, USA
- Graduate School of Biomedical Sciences and Engineering, University of Maine, Orono, Maine 04469, USA
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Fabbri R, Spennato D, Conte G, Konstantoulaki A, Lazzarini C, Saracino E, Nicchia GP, Frigeri A, Zamboni R, Spray DC, Benfenati V. The emerging science of Glioception: Contribution of glia in sensing, transduction, circuit integration of interoception. Pharmacol Ther 2023; 245:108403. [PMID: 37024060 DOI: 10.1016/j.pharmthera.2023.108403] [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: 10/13/2022] [Revised: 03/29/2023] [Accepted: 03/30/2023] [Indexed: 04/08/2023]
Abstract
Interoception is the process by which the nervous system regulates internal functions to achieve homeostasis. The role of neurons in interoception has received considerable recent attention, but glial cells also contribute. Glial cells can sense and transduce signals including osmotic, chemical, and mechanical status of extracellular milieu. Their ability to dynamically communicate "listening" and "talking" to neurons is necessary to monitor and regulate homeostasis and information integration in the nervous system. This review introduces the concept of "Glioception" and focuses on the process by which glial cells sense, interpret and integrate information about the inner state of the organism. Glial cells are ideally positioned to act as sensors and integrators of diverse interoceptive signals and can trigger regulatory responses via modulation of the activity of neuronal networks, both in physiological and pathological conditions. We believe that understanding and manipulating glioceptive processes and underlying molecular mechanisms provide a key path to develop new therapies for the prevention and alleviation of devastating interoceptive dysfunctions, among which pain is emphasized here with more focused details.
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Affiliation(s)
- Roberta Fabbri
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy; Department of Electrical, Electronic, and Information Engineering "Guglielmo Marconi", University of Bologna, viale del Risorgimento 2, 40136 Bologna, Italy.
| | - Diletta Spennato
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy; Department of Bioscience, Biotechnologies and Biopharmaceutics, Centre of Excellence in Comparative Genomics, University of Bari "Aldo Moro", Bari, BA, Italy
| | - Giorgia Conte
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy
| | - Aikaterini Konstantoulaki
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy; Department of Chemistry "Giacomo Ciamician", University of Bologna, Via Selmi, 2, 40126 Bologna, BO, Italy
| | - Chiara Lazzarini
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy
| | - Emanuela Saracino
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy
| | - Grazia Paola Nicchia
- School of Medicine, Basic Medical Sciences, Neuroscience and Sense Organs, University of Bari "Aldo Moro", Bari, BA, Italy; Department of Bioscience, Biotechnologies and Biopharmaceutics, Centre of Excellence in Comparative Genomics, University of Bari "Aldo Moro", Bari, BA, Italy
| | - Antonio Frigeri
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA; Department of Bioscience, Biotechnologies and Biopharmaceutics, Centre of Excellence in Comparative Genomics, University of Bari "Aldo Moro", Bari, BA, Italy
| | - Roberto Zamboni
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy
| | - David C Spray
- Department of Neuroscience, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
| | - Valentina Benfenati
- Institute for Organic Synthesis and Photoreactivity (ISOF), National Research Council of Italy (CNR), Via P. Gobetti 101, I-40129 Bologna, Italy.
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Parajuli B, Koizumi S. Strategies for Manipulating Microglia to Determine Their Role in the Healthy and Diseased Brain. Neurochem Res 2023; 48:1066-1076. [PMID: 36085395 PMCID: PMC9462627 DOI: 10.1007/s11064-022-03742-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 08/08/2022] [Accepted: 08/29/2022] [Indexed: 11/30/2022]
Abstract
Microglia are the specialized macrophages of the central nervous system and play an important role in neural circuit development, modulating neurotransmission, and maintaining brain homeostasis. Microglia in normal brain is quiescent and show ramified morphology with numerous branching processes. They constantly survey their surrounding microenvironment through the extension and retraction of their processes and interact with neurons, astrocytes, and blood vessels using these processes. Microglia respond quickly to any pathological event in the brain by assuming ameboid morphology devoid of branching processes and restore homeostasis. However, when there is chronic inflammation, microglia may lose their homeostatic functions and secrete various proinflammatory cytokines and mediators that initiate neural dysfunction and neurodegeneration. In this article, we review the role of microglia in the normal brain and in various pathological brain conditions, such as Alzheimer's disease and multiple sclerosis. We describe strategies to manipulate microglia, focusing on depletion, repopulation, and replacement, and we discuss their therapeutic potential.
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Affiliation(s)
- Bijay Parajuli
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan
- GLIA Center, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan
| | - Schuichi Koizumi
- Department of Neuropharmacology, Interdisciplinary Graduate School of Medicine, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan.
- GLIA Center, University of Yamanashi, 1110 Shimokato, Chuo, Yamanashi, 409-3898, Japan.
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Alaghband Y, Allen BD, Kramár EA, Zhang R, Drayson OG, Ru N, Petit B, Almeida A, Doan NL, Wood MA, Baulch JE, Ballesteros-Zebadua P, Vozenin MC, Limoli CL. Uncovering the Protective Neurologic Mechanisms of Hypofractionated FLASH Radiotherapy. CANCER RESEARCH COMMUNICATIONS 2023; 3:725-737. [PMID: 37377749 PMCID: PMC10135433 DOI: 10.1158/2767-9764.crc-23-0117] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 03/26/2023] [Accepted: 03/28/2023] [Indexed: 06/29/2023]
Abstract
Implementation of ultra-high dose-rate FLASH radiotherapy (FLASH-RT) is rapidly gaining traction as a unique cancer treatment modality able to dramatically minimize normal tissue toxicity while maintaining antitumor efficacy compared with standard-of-care radiotherapy at conventional dose rate (CONV-RT). The resultant improvements in the therapeutic index have sparked intense investigations in pursuit of the underlying mechanisms. As a preamble to clinical translation, we exposed non-tumor-bearing male and female mice to hypofractionated (3 × 10 Gy) whole brain FLASH- and CONV-RT to evaluate differential neurologic responses using a comprehensive panel of functional and molecular outcomes over a 6-month follow-up. In each instance, extensive and rigorous behavioral testing showed FLASH-RT to preserve cognitive indices of learning and memory that corresponded to a similar protection of synaptic plasticity as measured by long-term potentiation (LTP). These beneficial functional outcomes were not found after CONV-RT and were linked to a preservation of synaptic integrity at the molecular (synaptophysin) level and to reductions in neuroinflammation (CD68+ microglia) throughout specific brain regions known to be engaged by our selected cognitive tasks (hippocampus, medial prefrontal cortex). Ultrastructural changes in presynaptic/postsynaptic bouton (Bassoon/Homer-1 puncta) within these same regions of the brain were not found to differ in response to dose rate. With this clinically relevant dosing regimen, we provide a mechanistic blueprint from synapse to cognition detailing how FLASH-RT reduces normal tissue complications in the irradiated brain. Significance Functional preservation of cognition and LTP after hypofractionated FLASH-RT are linked to a protection of synaptic integrity and a reduction in neuroinflammation over protracted after irradiation times.
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Affiliation(s)
- Yasaman Alaghband
- Department of Radiation Oncology, University of California, Irvine, California
| | - Barrett D. Allen
- Department of Radiation Oncology, University of California, Irvine, California
| | - Eniko A. Kramár
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - Richard Zhang
- Department of Radiation Oncology, University of California, Irvine, California
| | - Olivia G.G. Drayson
- Department of Radiation Oncology, University of California, Irvine, California
| | - Ning Ru
- Department of Radiation Oncology, University of California, Irvine, California
| | - Benoit Petit
- Laboratory of Radiation Oncology, Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Aymeric Almeida
- Laboratory of Radiation Oncology, Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Ngoc-Lien Doan
- Department of Radiation Oncology, University of California, Irvine, California
| | - Marcelo A. Wood
- Department of Neurobiology and Behavior, University of California, Irvine, California
| | - Janet E. Baulch
- Department of Radiation Oncology, University of California, Irvine, California
| | - Paola Ballesteros-Zebadua
- Laboratory of Radiation Oncology, Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
- Instituto Nacional de Neurología y Neurocirugía MVS, México City, México
| | - Marie-Catherine Vozenin
- Laboratory of Radiation Oncology, Department of Radiation Oncology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Charles L. Limoli
- Department of Radiation Oncology, University of California, Irvine, California
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Ritzel RM, Li Y, Jiao Y, Lei Z, Doran SJ, He J, Shahror RA, Henry RJ, Khan R, Tan C, Liu S, Stoica BA, Faden AI, Szeto G, Loane DJ, Wu J. Brain injury accelerates the onset of a reversible age-related microglial phenotype associated with inflammatory neurodegeneration. SCIENCE ADVANCES 2023; 9:eadd1101. [PMID: 36888713 PMCID: PMC9995070 DOI: 10.1126/sciadv.add1101] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 02/02/2023] [Indexed: 06/18/2023]
Abstract
Lipofuscin is an autofluorescent (AF) pigment formed by lipids and misfolded proteins, which accumulates in postmitotic cells with advanced age. Here, we immunophenotyped microglia in the brain of old C57BL/6 mice (>18 months old) and demonstrate that in comparison to young mice, one-third of old microglia are AF, characterized by profound changes in lipid and iron content, phagocytic activity, and oxidative stress. Pharmacological depletion of microglia in old mice eliminated the AF microglia following repopulation and reversed microglial dysfunction. Age-related neurological deficits and neurodegeneration after traumatic brain injury (TBI) were attenuated in old mice lacking AF microglia. Furthermore, increased phagocytic activity, lysosomal burden, and lipid accumulation in microglia persisted for up to 1 year after TBI, were modified by APOE4 genotype, and chronically driven by phagocyte-mediated oxidative stress. Thus, AF may reflect a pathological state in aging microglia associated with increased phagocytosis of neurons and myelin and inflammatory neurodegeneration that can be further accelerated by TBI.
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Affiliation(s)
- Rodney M. Ritzel
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yun Li
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Yun Jiao
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland, Baltimore, MD 21250, USA
| | - Zhuofan Lei
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Sarah J. Doran
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Junyun He
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Rami A. Shahror
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Rebecca J. Henry
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Romeesa Khan
- Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77370, USA
| | - Chunfeng Tan
- Department of Neurology, McGovern Medical School, University of Texas Health Science Center at Houston, 6431 Fannin Street, Houston, TX 77370, USA
| | - Shaolin Liu
- Department of Anatomy, Howard University, Washington, DC 20059, USA
| | - Bogdan A. Stoica
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
| | - Alan I. Faden
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- University of Maryland Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD 21201, USA
| | - Gregory Szeto
- Department of Chemical, Biochemical, and Environmental Engineering, University of Maryland, Baltimore, MD 21250, USA
- Allen Institute for Immunology and Department of Pediatrics, University of Washington, Seattle, WA 98109, USA
| | - David J. Loane
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College, Dublin, Ireland
| | - Junfang Wu
- Department of Anesthesiology and Shock, Trauma and Anesthesiology Research (STAR) Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
- University of Maryland Center to Advance Chronic Pain Research, University of Maryland, Baltimore, MD 21201, USA
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Shelton-Gibbs S, Benderoth J, Gaykema RP, Straub J, Okojie KA, Uweru JO, Lentferink DH, Rajbanshi B, Cowan MN, Patel B, Campos-Salazar AB, Perez-Reyes E, Eyo UB. Microglia play beneficial roles in multiple experimental seizure models. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.04.531090. [PMID: 36945556 PMCID: PMC10028974 DOI: 10.1101/2023.03.04.531090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
Abstract
Seizure disorders are common, affecting both the young and the old. Currently available antiseizure drugs are ineffective in a third of patients and have been developed with a focus on known neurocentric mechanisms, raising the need for investigations into alternative and complementary mechanisms that contribute to seizure generation or its containment. Neuroinflammation, broadly defined as the activation of immune cells and molecules in the central nervous system (CNS), has been proposed to facilitate seizure generation, although the specific cells involved in these processes remain inadequately understood. The role of microglia, the primary inflammation-competent cells of the brain, is debated since previous studies were conducted using approaches that were less specific to microglia or had inherent confounds. Using a selective approach to target microglia without such side effects, we show a broadly beneficial role for microglia in limiting chemoconvulsive, electrical, and hyperthermic seizures and argue for a further understanding of microglial contributions to contain seizures.
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Affiliation(s)
- Synphane Shelton-Gibbs
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, VA, USA
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Jordan Benderoth
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Ronald P. Gaykema
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Justyna Straub
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Kenneth A. Okojie
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Joseph O. Uweru
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA
| | - Dennis H. Lentferink
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Binita Rajbanshi
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Maureen N. Cowan
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA
| | - Brij Patel
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Anthony Brayan Campos-Salazar
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
| | - Edward Perez-Reyes
- Department of Pharmacology, University of Virginia, Charlottesville, Virginia, USA
| | - Ukpong B. Eyo
- Brain Immunology and Glia Center, University of Virginia, Charlottesville, VA, USA
- Department of Neuroscience, University of Virginia, Charlottesville, VA, USA
- Neuroscience Graduate Program, University of Virginia, Charlottesville, Virginia, USA
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Aguilar-Hernández L, Alejandre R, César Morales-Medina J, Iannitti T, Flores G. Cellular mechanisms in brain aging: Focus on physiological and pathological aging. J Chem Neuroanat 2023; 128:102210. [PMID: 36496000 DOI: 10.1016/j.jchemneu.2022.102210] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 11/28/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022]
Abstract
Aging is a natural phenomenon characterized by accumulation of cellular damage and debris. Oxidative stress, cellular senescence, sustained inflammation, and DNA damage are the main cellular processes characteristic of aging associated with morphological and functional decline. These effects tend to be more pronounced in tissues with high metabolic rates such as the brain, mainly in regions such as the prefrontal cortex, hippocampus, and amygdala. These regions are highly related to cognitive behavior, and therefore their atrophy usually leads to decline in processes such as memory and learning. These cognitive declines can occur in physiological aging and are exacerbated in pathological aging. In this article, we review the cellular processes that underlie the triggers of aging and how they relate to one another, causing the atrophy of nerve tissue that is typical of aging. The main topic of this review to determine the central factor that triggers all the cellular processes that lead to cellular aging and discriminate between normal and pathological aging. Finally, we review how the use of supplements with antioxidant and anti-inflammatory properties reduces the cognitive decline typical of aging, which reinforces the hypothesis of oxidative stress and cellular damage as contributors of physiological atrophy of aging. Moreover, cumulative evidence suggests their possible use as therapies, which improve the aging population's quality of life.
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Affiliation(s)
- Leonardo Aguilar-Hernández
- Lab. Neuropsiquiatría, Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, 14 Sur 6301, San Manuel 72570, Puebla, Mexico; Departamento de Fisiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Ricardo Alejandre
- Departamento de Fisiología, Escuela Nacional de Ciencias Biológicas, Instituto Politécnico Nacional, Ciudad de México, Mexico
| | - Julio César Morales-Medina
- Centro de Investigación en Reproducción Animal, CINVESTAV-Universidad Autónoma de Tlaxcala, AP 62, CP 90000 Tlaxcala, Mexico
| | - Tommaso Iannitti
- University of Ferrara, Department of Medical Sciences, Section of Experimental Medicine, Via Fossato di Mortara 70, 44121 Ferrara, Italy
| | - Gonzalo Flores
- Lab. Neuropsiquiatría, Instituto de Fisiología, Benemérita Universidad Autónoma de Puebla, 14 Sur 6301, San Manuel 72570, Puebla, Mexico.
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Carlson ER, Guerin SP, Nixon K, Fonken LK. The neuroimmune system - Where aging and excess alcohol intersect. Alcohol 2023; 107:153-167. [PMID: 36150610 PMCID: PMC10023388 DOI: 10.1016/j.alcohol.2022.08.009] [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: 06/07/2022] [Revised: 08/21/2022] [Accepted: 08/31/2022] [Indexed: 01/05/2023]
Abstract
As the percentage of the global population over age 65 grows, and with it a subpopulation of individuals with alcohol use disorder (AUD), understanding the effect of alcohol on the aged brain is of utmost importance. Neuroinflammation is implicated in both natural aging as well as alcohol use, and its role in alterations to brain morphology and function may be exacerbated in aging individuals who drink alcohol to excess. The neuroimmune response to alcohol in aging is complex. The few studies investigating this issue have reported heightened basal activity and either hypo- or hyper-reactivity to an alcohol challenge. This review of preclinical research will first introduce key players of the immune system, then explore changes in neuroimmune function with aging or alcohol alone, with discussion of vulnerable brain regions, changes in cytokines, and varied reactions of microglia and astrocytes. We will then consider different levels of alcohol exposure, relevant animal models of AUD, and neuroimmune activation by alcohol across the lifespan. By identifying key findings, challenges, and targets for future research, we hope to bring more attention and resources to this underexplored area of inquiry.
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Affiliation(s)
- Erika R Carlson
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, United States
| | - Steven P Guerin
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, United States
| | - Kimberly Nixon
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, United States
| | - Laura K Fonken
- Division of Pharmacology and Toxicology, College of Pharmacy, The University of Texas at Austin, Austin, TX 78712, United States.
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Ng PY, McNeely TL, Baker DJ. Untangling senescent and damage-associated microglia in the aging and diseased brain. FEBS J 2023; 290:1326-1339. [PMID: 34873840 PMCID: PMC9167891 DOI: 10.1111/febs.16315] [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: 09/28/2021] [Revised: 11/16/2021] [Accepted: 12/06/2021] [Indexed: 01/10/2023]
Abstract
Microglial homeostasis has emerged as a critical mediator of health and disease in the central nervous system. In their neuroprotective role as the predominant immune cells of the brain, microglia surveil the microenvironment for debris and pathogens, while also promoting neurogenesis and performing maintenance on synapses. Chronological ageing, disease onset, or traumatic injury promotes irreparable damage or deregulated signaling to reinforce neurotoxic phenotypes in microglia. These insults may include cellular senescence, a stable growth arrest often accompanied by the production of a distinctive pro-inflammatory secretory phenotype, which may contribute to age- or disease-driven decline in neuronal health and cognition and is a potential novel therapeutic target. Despite this increased scrutiny, unanswered questions remain about what distinguishes senescent microglia and non-senescent microglia reacting to insults occurring in ageing, disease, and injury, and how central the development of senescence is in their pivot from guardian to assailant. To intelligently design future studies to untangle senescent microglia from other primed and reactionary states, specific criteria must be developed that define this population and allow for comparisons between different model systems. Comparing microglial activity seen in homeostasis, ageing, disease, and injury allows for a more coherent understanding of when and how senescent and other harmful microglial subpopulations should be targeted.
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Affiliation(s)
- Pei Y Ng
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - Taylor L McNeely
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA
| | - Darren J Baker
- Department of Biochemistry and Molecular Biology, Mayo Clinic, Rochester, MN, USA.,Department of Pediatric and Adolescent Medicine, Mayo Clinic, Rochester, MN, USA
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Tran KM, Kawauchi S, Kramár EA, Rezaie N, Liang HY, Sakr JS, Gomez-Arboledas A, Arreola MA, Cunha CD, Phan J, Wang S, Collins S, Walker A, Shi KX, Neumann J, Filimban G, Shi Z, Milinkeviciute G, Javonillo DI, Tran K, Gantuz M, Forner S, Swarup V, Tenner AJ, LaFerla FM, Wood MA, Mortazavi A, MacGregor GR, Green KN. A Trem2 R47H mouse model without cryptic splicing drives age- and disease-dependent tissue damage and synaptic loss in response to plaques. Mol Neurodegener 2023; 18:12. [PMID: 36803190 PMCID: PMC9938579 DOI: 10.1186/s13024-023-00598-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2022] [Accepted: 01/19/2023] [Indexed: 02/19/2023] Open
Abstract
BACKGROUND The TREM2 R47H variant is one of the strongest genetic risk factors for late-onset Alzheimer's Disease (AD). Unfortunately, many current Trem2 R47H mouse models are associated with cryptic mRNA splicing of the mutant allele that produces a confounding reduction in protein product. To overcome this issue, we developed the Trem2R47H NSS (Normal Splice Site) mouse model in which the Trem2 allele is expressed at a similar level to the wild-type Trem2 allele without evidence of cryptic splicing products. METHODS Trem2R47H NSS mice were treated with the demyelinating agent cuprizone, or crossed with the 5xFAD mouse model of amyloidosis, to explore the impact of the TREM2 R47H variant on inflammatory responses to demyelination, plaque development, and the brain's response to plaques. RESULTS Trem2R47H NSS mice display an appropriate inflammatory response to cuprizone challenge, and do not recapitulate the null allele in terms of impeded inflammatory responses to demyelination. Utilizing the 5xFAD mouse model, we report age- and disease-dependent changes in Trem2R47H NSS mice in response to development of AD-like pathology. At an early (4-month-old) disease stage, hemizygous 5xFAD/homozygous Trem2R47H NSS (5xFAD/Trem2R47H NSS) mice have reduced size and number of microglia that display impaired interaction with plaques compared to microglia in age-matched 5xFAD hemizygous controls. This is associated with a suppressed inflammatory response but increased dystrophic neurites and axonal damage as measured by plasma neurofilament light chain (NfL) level. Homozygosity for Trem2R47H NSS suppressed LTP deficits and loss of presynaptic puncta caused by the 5xFAD transgene array in 4-month-old mice. At a more advanced (12-month-old) disease stage 5xFAD/Trem2R47H NSS mice no longer display impaired plaque-microglia interaction or suppressed inflammatory gene expression, although NfL levels remain elevated, and a unique interferon-related gene expression signature is seen. Twelve-month old Trem2R47H NSS mice also display LTP deficits and postsynaptic loss. CONCLUSIONS The Trem2R47H NSS mouse is a valuable model that can be used to investigate age-dependent effects of the AD-risk R47H mutation on TREM2 and microglial function including its effects on plaque development, microglial-plaque interaction, production of a unique interferon signature and associated tissue damage.
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Affiliation(s)
- Kristine M. Tran
- Department of Neurobiology and Behavior, University of California, Irvine, USA
| | - Shimako Kawauchi
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, USA
- Transgenic Mouse Facility, Office of Research, ULAR, Irvine, USA
| | - Enikö A. Kramár
- Department of Neurobiology and Behavior, University of California, Irvine, USA
| | - Narges Rezaie
- Department of Developmental and Cell Biology, University of California, Irvine, USA
- Center for Complex Biological Systems, Irvine, USA
| | - Heidi Yahan Liang
- Department of Developmental and Cell Biology, University of California, Irvine, USA
- Center for Complex Biological Systems, Irvine, USA
| | - Jasmine S. Sakr
- Department of Pharmaceutical Sciences, University of California, Irvine, USA
| | | | - Miguel A. Arreola
- Department of Neurobiology and Behavior, University of California, Irvine, USA
| | - Celia da Cunha
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, USA
| | - Jimmy Phan
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, USA
| | - Shuling Wang
- Transgenic Mouse Facility, Office of Research, ULAR, Irvine, USA
| | - Sherilyn Collins
- Transgenic Mouse Facility, Office of Research, ULAR, Irvine, USA
| | - Amber Walker
- Transgenic Mouse Facility, Office of Research, ULAR, Irvine, USA
| | - Kai-Xuan Shi
- Transgenic Mouse Facility, Office of Research, ULAR, Irvine, USA
| | - Jonathan Neumann
- Transgenic Mouse Facility, Office of Research, ULAR, Irvine, USA
| | - Ghassan Filimban
- Department of Developmental and Cell Biology, University of California, Irvine, USA
| | - Zechuan Shi
- Department of Neurobiology and Behavior, University of California, Irvine, USA
| | - Giedre Milinkeviciute
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, USA
| | - Dominic I. Javonillo
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, USA
| | - Katelynn Tran
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, USA
| | - Magdalena Gantuz
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, USA
| | - Stefania Forner
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, USA
| | - Vivek Swarup
- Department of Neurobiology and Behavior, University of California, Irvine, USA
- Center for Complex Biological Systems, Irvine, USA
| | - Andrea J. Tenner
- Department of Neurobiology and Behavior, University of California, Irvine, USA
- Department of Molecular Biology & Biochemistry, University of California, Irvine, USA
- Department of Pathology and Laboratory Medicine, University of California, Irvine, USA
| | - Frank M. LaFerla
- Department of Neurobiology and Behavior, University of California, Irvine, USA
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, USA
| | - Marcelo A. Wood
- Department of Neurobiology and Behavior, University of California, Irvine, USA
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, USA
| | - Ali Mortazavi
- Department of Developmental and Cell Biology, University of California, Irvine, USA
- Center for Complex Biological Systems, Irvine, USA
| | - Grant R. MacGregor
- Transgenic Mouse Facility, Office of Research, ULAR, Irvine, USA
- Department of Developmental and Cell Biology, University of California, Irvine, USA
| | - Kim N. Green
- Department of Neurobiology and Behavior, University of California, Irvine, USA
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, USA
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47
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Kim GS, Harmon E, Gutierrez M, Stephenson J, Chauhan A, Banerjee A, Wise Z, Doan A, Wu T, Lee J, Jung JE, McCullough L, Wythe J, Marrelli S. Single-cell analysis identifies Ifi27l2a as a novel gene regulator of microglial inflammation in the context of aging and stroke. RESEARCH SQUARE 2023:rs.3.rs-2557290. [PMID: 36824976 PMCID: PMC9949241 DOI: 10.21203/rs.3.rs-2557290/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Microglia are key mediators of inflammatory responses within the brain, as they regulate pro-inflammatory responses while also limiting neuroinflammation via reparative phagocytosis. Thus, identifying genes that modulate microglial function may reveal novel therapeutic interventions for promoting better outcomes in diseases featuring extensive inflammation, such as stroke. To facilitate identification of potential mediators of inflammation, we performed single-cell RNA sequencing of aged mouse brains following stroke and found that Ifi27l2a was significantly up-regulated, particularly in microglia. The increased Ifi27l2a expression was further validated in microglial culture, stroke models with microglial depletion, and human autopsy samples. Ifi27l2a is known to be induced by interferons for viral host defense, however the role of Ifi27l2a in neurodegeneration is unknown. In vitro studies in cultured microglia demonstrated that Ifi27l2a overexpression causes neuroinflammation via reactive oxygen species. Interestingly, hemizygous deletion of Ifi27l2a significantly reduced gliosis in the thalamus following stroke, while also reducing neuroinflammation, indicating Ifi27l2a gene dosage is a critical mediator of neuroinflammation in ischemic stroke. Collectively, this study demonstrates that a novel gene, Ifi27l2a, regulates microglial function and neuroinflammation in the aged brain and following stroke. These findings suggest that Ifi27l2a may be a novel target for conferring cerebral protection post-stroke.
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Affiliation(s)
- Gab Seok Kim
- The University of Texas Health Science Center at Houston
| | | | | | | | | | | | - Zachary Wise
- The University of Texas Health Science Center at Houston
| | - Andrea Doan
- The University of Texas Health Science Center at Houston
| | - Ting Wu
- The University of Texas Health Science Center at Houston
| | - Juneyoung Lee
- The University of Texas Health Science Center at Houston
| | | | - Louise McCullough
- McGovern Medical School/University of Texas Health Science Center at Houston
| | | | - Sean Marrelli
- The University of Texas McGovern Medical School at Houston, 77030, TX
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48
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Arbaizar-Rovirosa M, Pedragosa J, Lozano JJ, Casal C, Pol A, Gallizioli M, Planas AM. Aged lipid-laden microglia display impaired responses to stroke. EMBO Mol Med 2023; 15:e17175. [PMID: 36541061 PMCID: PMC9906381 DOI: 10.15252/emmm.202217175] [Citation(s) in RCA: 22] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Revised: 11/30/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022] Open
Abstract
Microglial cells of the aged brain manifest signs of dysfunction that could contribute to the worse neurological outcome of stroke in the elderly. Treatment with colony-stimulating factor 1 receptor antagonists enables transient microglia depletion that is followed by microglia repopulation after treatment interruption, causing no known harm to mice. We tested whether this strategy restored microglia function and ameliorated stroke outcome in old mice. Cerebral ischemia/reperfusion induced innate immune responses in microglia highlighted by type I interferon and metabolic changes involving lipid droplet biogenesis. Old microglia accumulated lipids under steady state and displayed exacerbated innate immune responses to stroke. Microglia repopulation in old mice reduced lipid-laden microglia, and the cells exhibited reduced inflammatory responses to ischemia. Moreover, old mice with renewed microglia showed improved motor function 2 weeks after stroke. We conclude that lipid deposits in aged microglia impair the cellular responses to ischemia and worsen functional recovery in old mice.
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Affiliation(s)
- Maria Arbaizar-Rovirosa
- Department of Neuroscience and Experimental Therapeutics, Instituto de Investigaciones Biomédicas de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Jordi Pedragosa
- Department of Neuroscience and Experimental Therapeutics, Instituto de Investigaciones Biomédicas de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Juan J Lozano
- Bioinformatics Platform, Centro de Investigación Biomédica en Red Enfermedades Hepáticas y Digestivas (CIBEREHD), Barcelona, Spain
| | - Carme Casal
- Microscopy Service, Instituto de Investigaciones Biomédicas de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain
| | - Albert Pol
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain.,Department of Biomedical Sciences, Faculty of Medicine, Universitat de Barcelona, Barcelona, Spain.,Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Spain
| | - Mattia Gallizioli
- Department of Neuroscience and Experimental Therapeutics, Instituto de Investigaciones Biomédicas de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Anna M Planas
- Department of Neuroscience and Experimental Therapeutics, Instituto de Investigaciones Biomédicas de Barcelona (IIBB), Consejo Superior de Investigaciones Científicas (CSIC), Barcelona, Spain.,Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
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49
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Tan X, Wang J, Yao J, Yuan J, Dai Y, Sun M, Zhang T, Yang J, Cai W, Qiu L, Sun J. Microglia participate in postoperative cognitive dysfunction by mediating the loss of inhibitory synapse through the complement pathway. Neurosci Lett 2023; 796:137049. [PMID: 36608926 DOI: 10.1016/j.neulet.2023.137049] [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: 09/22/2022] [Revised: 12/13/2022] [Accepted: 01/01/2023] [Indexed: 01/05/2023]
Abstract
BACKGROUND Elderly patients after surgery are prone to cognitive decline known as postoperative cognitive dysfunction (POCD). Several studies have shown that the microglial activation and the increase of complement protein expression in hippocampus induced by surgery may be related to the pathogenesis of POCD. The purpose of this study was to determine whether microglia and complement system were involved in cognitive dysfunction in aged mice. METHODS The POCD model was established by exploratory laparotomy in 15-month-old male C57BL/6J mice and animal behavioral tests were performed to test hippocampal-dependent memory capacity. Minocycline was used to suppress the activation of microglia, and complement 3 receptor inhibitor was used to suppress the association between microglia and complement 3. Western blot and immunofluorescence were used to detect the microglial activation, complement protein, and synaptic protein expressions. RESULTS Operation induced hippocampal-dependent memory impairment (P < 0.01), which was accompanied by microglial activation (P < 0.01). There was also a significant reduction in inhibitory synaptic protein expression in the hippocampus of mice in the surgery group (P < 0.01). However, minocycline, a microglia inhibitor, rescued all the above changes. In addition, C3RI intervention inhibited the phagocytosis of inhibitory synapses by microglia (P < 0.05) and improved the cognitive function of mice (P < 0.01). CONCLUSION Microglia participate in postoperative cognitive dysfunction by mediating inhibitory synaptic loss through the complement pathway.
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Affiliation(s)
- Xiaoxiang Tan
- Department of Anesthesiology, Surgery and Pain Management, Zhongda Hospital, the School of Medicine, Southeast University, Nanjing, Jiangsu Province, China
| | - Jiajia Wang
- Department of Anesthesiology, Surgery and Pain Management, Zhongda Hospital, the School of Medicine, Southeast University, Nanjing, Jiangsu Province, China
| | - Juan Yao
- Department of Anesthesiology, Surgery and Pain Management, Zhongda Hospital, the School of Medicine, Southeast University, Nanjing, Jiangsu Province, China
| | - Jing Yuan
- Department of Anesthesiology, Surgery and Pain Management, Zhongda Hospital, the School of Medicine, Southeast University, Nanjing, Jiangsu Province, China
| | - Yuchen Dai
- Department of Anesthesiology, Surgery and Pain Management, Zhongda Hospital, the School of Medicine, Southeast University, Nanjing, Jiangsu Province, China
| | - Menghan Sun
- Department of Anesthesiology, Surgery and Pain Management, Zhongda Hospital, the School of Medicine, Southeast University, Nanjing, Jiangsu Province, China
| | - Tianhao Zhang
- Department of Anesthesiology, Surgery and Pain Management, Zhongda Hospital, the School of Medicine, Southeast University, Nanjing, Jiangsu Province, China
| | - Jiaojiao Yang
- Department of Anesthesiology, Surgery and Pain Management, Zhongda Hospital, the School of Medicine, Southeast University, Nanjing, Jiangsu Province, China
| | - Wenlan Cai
- Department of Anesthesiology, Surgery and Pain Management, Zhongda Hospital, the School of Medicine, Southeast University, Nanjing, Jiangsu Province, China
| | - Lili Qiu
- Department of Anesthesiology, Surgery and Pain Management, Zhongda Hospital, the School of Medicine, Southeast University, Nanjing, Jiangsu Province, China.
| | - Jie Sun
- Department of Anesthesiology, Surgery and Pain Management, Zhongda Hospital, the School of Medicine, Southeast University, Nanjing, Jiangsu Province, China.
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50
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Grant CV, Sullivan KA, Wentworth KM, Otto LD, Strehle LD, Otero JJ, Pyter LM. Microglia are implicated in the development of paclitaxel chemotherapy-associated cognitive impairment in female mice. Brain Behav Immun 2023; 108:221-232. [PMID: 36494047 PMCID: PMC9899068 DOI: 10.1016/j.bbi.2022.12.004] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 10/30/2022] [Accepted: 12/03/2022] [Indexed: 12/12/2022] Open
Abstract
Chemotherapy remains a mainstay in the treatment of many types of cancer even though it is associated with debilitating behavioral side effects referred to as "chemobrain," including difficulty concentrating and memory impairment. The predominant hypothesis in the field is that systemic inflammation drives these cognitive impairments, although the brain mechanisms by which this occurs remain poorly understood. Here, we hypothesized that microglia are activated by chemotherapy and drive chemotherapy-associated cognitive impairments. To test this hypothesis, we treated female C57BL/6 mice with a clinically-relevant regimen of a common chemotherapeutic, paclitaxel (6 i.p. doses at 30 mg/kg), which impairs memory of an aversive stimulus as assessed via a contextual fear conditioning (CFC) paradigm. Paclitaxel increased the percent area of IBA1 staining in the dentate gyrus of the hippocampus. Moreover, using a machine learning random forest classifier we identified immunohistochemical features of reactive microglia in multiple hippocampal subregions that were distinct between vehicle- and paclitaxel-treated mice. Paclitaxel treatment also increased gene expression of inflammatory cytokines in a microglia-enriched population of cells from mice. Lastly, a selective inhibitor of colony stimulating factor 1 receptor, PLX5622, was employed to deplete microglia and then assess CFC performance following paclitaxel treatment. PLX5622 significantly reduced hippocampal gene expression of paclitaxel-induced proinflammatory cytokines and restored memory, suggesting that microglia play a critical role in the development of chemotherapy-associated neuroinflammation and cognitive impairments. This work provides critical evidence that microglia drive paclitaxel-associated cognitive impairments, a key mechanistic detail for determining preventative and intervention strategies for these burdensome side effects.
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Affiliation(s)
- Corena V Grant
- Institute for Behavioral Medicine Research, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Kyle A Sullivan
- Institute for Behavioral Medicine Research, Ohio State University Wexner Medical Center, Columbus, OH, USA; Computational and Predictive Biology, Oak Ridge National Laboratory, Oak Ridge, TN, USA
| | - Kylie M Wentworth
- Institute for Behavioral Medicine Research, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Lauren D Otto
- Institute for Behavioral Medicine Research, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Lindsay D Strehle
- Institute for Behavioral Medicine Research, Ohio State University Wexner Medical Center, Columbus, OH, USA
| | - Jose J Otero
- Department of Pathology, Ohio State University, Columbus, OH, USA
| | - Leah M Pyter
- Institute for Behavioral Medicine Research, Ohio State University Wexner Medical Center, Columbus, OH, USA; Departments of Psychiatry and Behavioral Health, Ohio State University, Columbus, OH, USA; Department of Neuroscience, Ohio State University, Columbus, OH, USA.
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