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Zhu J, Liu X, Deng Y, Li D, Yu T, Zhu D. Tissue optical clearing for 3D visualization of vascular networks: A review. Vascul Pharmacol 2021; 141:106905. [PMID: 34506969 DOI: 10.1016/j.vph.2021.106905] [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: 06/25/2021] [Revised: 08/31/2021] [Accepted: 09/02/2021] [Indexed: 12/01/2022]
Abstract
Reconstruction of the vasculature of intact tissues/organs down to the capillary level is essential for understanding the development and remodeling of vascular networks under physiological and pathological conditions. Optical imaging techniques can provide sufficient resolution to distinguish small vessels with several microns, but the imaging depth is somewhat limited due to the high light scattering of opaque tissue. Recently, various tissue optical clearing methods have been developed to overcome light attenuation and improve the imaging depth both for ex-vivo and in-vivo visualizations. Tissue clearing combined with vessel labeling techniques and advanced optical tomography enables successful mapping of the vasculature of different tissues/organs, as well as dynamically monitoring vessel function under normal and pathological conditions. Here, we briefly introduce the commonly-used labeling strategies for entire vascular networks, the current tissue optical clearing techniques available for various tissues, as well as the advanced optical imaging techniques for fast, high-resolution structural and functional imaging for blood vessels. We also discuss the applications of these techniques in the 3D visualization of vascular networks in normal tissues, and the vascular remodeling in several typical pathological models in clinical research. This review is expected to provide valuable insights for researchers to study the potential mechanisms of various vessel-associated diseases using tissue optical clearing pipeline.
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Affiliation(s)
- Jingtan Zhu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Xiaomei Liu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Yating Deng
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Dongyu Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
| | - Tingting Yu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China.
| | - Dan Zhu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China; MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, Hubei 430074, China
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Radandish M, Khalilian P, Esmaeil N. The Role of Distinct Subsets of Macrophages in the Pathogenesis of MS and the Impact of Different Therapeutic Agents on These Populations. Front Immunol 2021; 12:667705. [PMID: 34489926 PMCID: PMC8417824 DOI: 10.3389/fimmu.2021.667705] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 07/31/2021] [Indexed: 01/03/2023] Open
Abstract
Multiple sclerosis (MS) is a demyelinating inflammatory disorder of the central nervous system (CNS). Besides the vital role of T cells, other immune cells, including B cells, innate immune cells, and macrophages (MФs), also play a critical role in MS pathogenesis. Tissue-resident MФs in the brain’s parenchyma, known as microglia and monocyte-derived MФs, enter into the CNS following alterations in CNS homeostasis that induce inflammatory responses in MS. Although the neuroprotective and anti-inflammatory actions of monocyte-derived MФs and resident MФs are required to maintain CNS tolerance, they can release inflammatory cytokines and reactivate primed T cells during neuroinflammation. In the CNS of MS patients, elevated myeloid cells and activated MФs have been found and associated with demyelination and axonal loss. Thus, according to the role of MФs in neuroinflammation, they have attracted attention as a therapeutic target. Also, due to their different origin, location, and turnover, other strategies may require to target the various myeloid cell populations. Here we review the role of distinct subsets of MФs in the pathogenesis of MS and different therapeutic agents that target these cells.
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Affiliation(s)
- Maedeh Radandish
- Department of Immunology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Parvin Khalilian
- Department of Immunology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran
| | - Nafiseh Esmaeil
- Department of Immunology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.,Environment Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
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Hubert V, Hristovska I, Karpati S, Benkeder S, Dey A, Dumot C, Amaz C, Chounlamountri N, Watrin C, Comte J, Chauveau F, Brun E, Marche P, Lerouge F, Parola S, Berthezène Y, Vorup‐Jensen T, Pascual O, Wiart M. Multimodal Imaging with NanoGd Reveals Spatiotemporal Features of Neuroinflammation after Experimental Stroke. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2021; 8:e2101433. [PMID: 34197055 PMCID: PMC8425862 DOI: 10.1002/advs.202101433] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/12/2021] [Indexed: 05/09/2023]
Abstract
The purpose of this study is to propose and validate a preclinical in vivo magnetic resonance imaging (MRI) tool to monitor neuroinflammation following ischemic stroke, based on injection of a novel multimodal nanoprobe, NanoGd, specifically designed for internalization by phagocytic cells. First, it is verified that NanoGd is efficiently internalized by microglia in vitro. In vivo MRI coupled with intravenous injection of NanoGd in a permanent middle cerebral artery occlusion mouse model results in hypointense signals in the ischemic lesion. In these mice, longitudinal two-photon intravital microscopy shows NanoGd internalization by activated CX3CR1-GFP/+ cells. Ex vivo analysis, including phase contrast imaging with synchrotron X-ray, histochemistry, and transmission electron microscopy corroborate NanoGd accumulation within the ischemic lesion and uptake by immune phagocytic cells. Taken together, these results confirm the potential of NanoGd-enhanced MRI as an imaging biomarker of neuroinflammation at the subacute stage of ischemic stroke. As far as it is known, this work is the first to decipher the working mechanism of MR signals induced by a nanoparticle passively targeted at phagocytic cells by performing intravital microscopy back-to-back with MRI. Furthermore, using a gadolinium-based rather than an iron-based contrast agent raises future perspectives for the development of molecular imaging with emerging computed tomography technologies.
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Affiliation(s)
- Violaine Hubert
- Univ‐LyonIRIS TeamCarMeN LaboratoryInserm U1060INRA U1397INSA LyonUniversité Claude Bernard Lyon 1Groupement Hospitalier Est59 bd. PinelBron69500France
| | - Ines Hristovska
- SYNATAC TeamInstitut NeuroMyoGèneUniversité Claude Bernard Lyon 1CNRS UMR 5310, INSERM U1217Faculté de Médecine et de Pharmacie8 avenue RockefellerLyon69008France
| | - Szilvia Karpati
- Université de LyonÉcole Normale Supérieure de LyonCNRS UMR 5182Université Claude Bernard Lyon 1Laboratoire de ChimieLyonF69342France
| | - Sarah Benkeder
- SYNATAC TeamInstitut NeuroMyoGèneUniversité Claude Bernard Lyon 1CNRS UMR 5310, INSERM U1217Faculté de Médecine et de Pharmacie8 avenue RockefellerLyon69008France
| | - Arindam Dey
- Institut pour l'Avancée des BiosciencesCentre de Recherche UGA / Inserm U 1209 / CNRS UMR 5309Site Santé ‐ Allée des AlpesLa Tronche38700France
| | - Chloé Dumot
- Univ‐LyonIRIS TeamCarMeN LaboratoryInserm U1060INRA U1397INSA LyonUniversité Claude Bernard Lyon 1Groupement Hospitalier Est59 bd. PinelBron69500France
| | - Camille Amaz
- Clinical Investigation CenterHospices Civils de LyonLouis Pradel Hospital28 avenue Doyen LépineBron69500France
| | - Naura Chounlamountri
- SYNATAC TeamInstitut NeuroMyoGèneUniversité Claude Bernard Lyon 1CNRS UMR 5310, INSERM U1217Faculté de Médecine et de Pharmacie8 avenue RockefellerLyon69008France
| | - Chantal Watrin
- SYNATAC TeamInstitut NeuroMyoGèneUniversité Claude Bernard Lyon 1CNRS UMR 5310, INSERM U1217Faculté de Médecine et de Pharmacie8 avenue RockefellerLyon69008France
| | - Jean‐Christophe Comte
- FORGETTING TeamLyon Neuroscience Research Center (CRNL)CNRS UMR5292INSERM U1028Université Claude Bernard Lyon 1Centre Hospitalier Le Vinatier ‐ Bâtiment 462 ‐ Neurocampus Michel Jouvet95 boulevard PinelBron69675France
| | - Fabien Chauveau
- Université de LyonLyon Neuroscience Research Center (CRNL)CNRS UMR5292INSERM U1028Université Claude Bernard Lyon 1Groupement Hospitalier Est ‐ CERMEP59 bd PinelBron Cedex69677France
| | - Emmanuel Brun
- Synchrotron Radiation for Biomedical Research (STROBE)UA7 INSERMUniversité Grenoble AlpesMedical Beamline at the European Synchrotron Radiation Facility71 Avenue des MartyrsGrenoble Cedex 938043France
| | - Patrice Marche
- Institut pour l'Avancée des BiosciencesCentre de Recherche UGA / Inserm U 1209 / CNRS UMR 5309Site Santé ‐ Allée des AlpesLa Tronche38700France
| | - Fréderic Lerouge
- Université de LyonÉcole Normale Supérieure de LyonCNRS UMR 5182Université Claude Bernard Lyon 1Laboratoire de ChimieLyonF69342France
| | - Stéphane Parola
- Université de LyonÉcole Normale Supérieure de LyonCNRS UMR 5182Université Claude Bernard Lyon 1Laboratoire de ChimieLyonF69342France
| | - Yves Berthezène
- Univ‐LyonCreatis LaboratoryCNRS UMR5220Inserm U1044INSA LyonVilleurbanne Cedex69621France
| | - Thomas Vorup‐Jensen
- Department of BiomedicineBiophysical Immunology LaboratoryAarhus UniversityAarhus CDK‐8000Denmark
| | - Olivier Pascual
- SYNATAC TeamInstitut NeuroMyoGèneUniversité Claude Bernard Lyon 1CNRS UMR 5310, INSERM U1217Faculté de Médecine et de Pharmacie8 avenue RockefellerLyon69008France
| | - Marlène Wiart
- Univ‐LyonIRIS TeamCarMeN LaboratoryInserm U1060INRA U1397INSA LyonUniversité Claude Bernard Lyon 1Groupement Hospitalier Est59 bd. PinelBron69500France
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Microglia as the Critical Regulators of Neuroprotection and Functional Recovery in Cerebral Ischemia. Cell Mol Neurobiol 2021; 42:2505-2525. [PMID: 34460037 DOI: 10.1007/s10571-021-01145-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 08/25/2021] [Indexed: 12/13/2022]
Abstract
Microglial activation is considered as the critical pathogenic event in diverse central nervous system disorders including cerebral ischemia. Proinflammatory responses of activated microglia have been well reported in the ischemic brain and neuroinflammatory responses of activated microglia have been believed to be the potential therapeutic strategy. However, despite having proinflammatory roles, microglia can have significant anti-inflammatory roles and they are associated with the production of growth factors which are responsible for neuroprotection and recovery after ischemic injury. Microglia can directly promote neuroprotection by preventing ischemic infarct expansion and promoting functional outcomes. Indirectly, microglia are involved in promoting anti-inflammatory responses, neurogenesis, and angiogenesis in the ischemic brain which are crucial pathophysiological events for ischemic recovery. In fact, anti-inflammatory cytokines and growth factors produced by microglia can promote neuroprotection and attenuate neurobehavioral deficits. In addition, microglia regulate phagocytosis, axonal regeneration, blood-brain barrier protection, white matter integrity, and synaptic remodeling, which are essential for ischemic recovery. Microglia can also regulate crosstalk with neurons and other cell types to promote neuroprotection and ischemic recovery. This review mainly focuses on the roles of microglia in neuroprotection and recovery following ischemic injury. Furthermore, this review also sheds the light on the therapeutic potential of microglia in stroke patients.
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Ortiz-Villatoro NN, Reyes-Garcia SZ, Freitas L, Rodrigues LD, Santos LEC, Faber J, Cavalheiro EA, Finsterer J, Scorza FA, de Almeida ACG, Scorza CA. Amazon rainforest rodents (Proechimys) are resistant to post-stroke epilepsy. Sci Rep 2021; 11:16780. [PMID: 34408211 PMCID: PMC8373885 DOI: 10.1038/s41598-021-96235-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 04/12/2021] [Indexed: 02/07/2023] Open
Abstract
There are no clinical interventions to prevent post-injury epilepsy, a common and devastating outcome after brain insults. Epileptogenic events that run from brain injury to epilepsy are poorly understood. Previous studies in our laboratory suggested Proechimys, an exotic Amazonian rodent, as resistant to acquired epilepsy development in post-status epilepticus models. The present comparative study was conducted to assess (1) stroke-related brain responses 24-h and 30 days after cortical photothrombosis and (2) post-stroke epilepsy between Proechimys rodents and Wistar rats, a traditional animal used for laboratory research. Proechimys group showed smaller volume of ischemic infarction and lesser glial activation than Wistar group. In contrast to Wistar rats, post-stroke decreased levels of pro-inflammatory cytokines and increased levels of anti-inflammatory mediators and growth factors were found in Proechimys. Electrophysiological signaling changes assessed by cortical spreading depression, in vitro and in vivo, showed that Wistar's brain is most severely affected by stroke. Chronic electrocorticographic recordings showed that injury did not lead to epilepsy in Proechimys whereas 88% of the Wistar rats developed post-stroke epilepsy. Science gains insights from comparative studies on diverse species. Proechimys rodents proved to be a useful animal model to study antiepileptogenic mechanisms after brain insults and complement conventional animal models.
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Affiliation(s)
- Nancy N. Ortiz-Villatoro
- grid.411249.b0000 0001 0514 7202Disciplina de Neurociência, Departamento de Neurologia/Neurocirurgia, Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, 04039-032 Brazil
| | - Selvin Z. Reyes-Garcia
- grid.10601.360000 0001 2297 2829Posgrado de Neurología, Facultad de Ciencias Médicas, Universidad Nacional Autónoma de Honduras, Tegucigalpa, Honduras
| | - Leandro Freitas
- grid.411249.b0000 0001 0514 7202Disciplina de Neurociência, Departamento de Neurologia/Neurocirurgia, Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, 04039-032 Brazil
| | - Laís D. Rodrigues
- grid.411249.b0000 0001 0514 7202Disciplina de Neurociência, Departamento de Neurologia/Neurocirurgia, Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, 04039-032 Brazil
| | - Luiz E. C. Santos
- grid.428481.30000 0001 1516 3599Neurociência Experimental e Computacional, Universidade Federal São João Del-Rey, São João del-Rei, Brazil
| | - Jean Faber
- grid.411249.b0000 0001 0514 7202Disciplina de Neurociência, Departamento de Neurologia/Neurocirurgia, Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, 04039-032 Brazil
| | - Esper A. Cavalheiro
- grid.411249.b0000 0001 0514 7202Disciplina de Neurociência, Departamento de Neurologia/Neurocirurgia, Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, 04039-032 Brazil
| | - Josef Finsterer
- grid.413303.60000 0004 0437 0893Krankenanstalt Rudolfstiftung, Mersserli Institute, Vienna, Austria
| | - Fulvio A. Scorza
- grid.411249.b0000 0001 0514 7202Disciplina de Neurociência, Departamento de Neurologia/Neurocirurgia, Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, 04039-032 Brazil
| | - Antônio C. G. de Almeida
- grid.428481.30000 0001 1516 3599Neurociência Experimental e Computacional, Universidade Federal São João Del-Rey, São João del-Rei, Brazil
| | - Carla A. Scorza
- grid.411249.b0000 0001 0514 7202Disciplina de Neurociência, Departamento de Neurologia/Neurocirurgia, Escola Paulista de Medicina/Universidade Federal de São Paulo (EPM/UNIFESP), São Paulo, 04039-032 Brazil
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Differential effects of the cell cycle inhibitor, olomoucine, on functional recovery and on responses of peri-infarct microglia and astrocytes following photothrombotic stroke in rats. J Neuroinflammation 2021; 18:168. [PMID: 34332596 PMCID: PMC8325288 DOI: 10.1186/s12974-021-02208-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2021] [Accepted: 07/02/2021] [Indexed: 11/17/2022] Open
Abstract
Background Following stroke, changes in neuronal connectivity in tissue surrounding the infarct play an important role in both spontaneous recovery of neurological function and in treatment-induced improvements in function. Microglia and astrocytes influence this process through direct interactions with the neurons and as major determinants of the local tissue environment. Subpopulations of peri-infarct glia proliferate early after stroke providing a possible target to modify recovery. Treatment with cell cycle inhibitors can reduce infarct volume and improve functional recovery. However, it is not known whether these inhibitors can influence neurological function or alter the responses of peri-infarct glia without reducing infarction. The present study aimed to address these issues by testing the effects of the cell cycle inhibitor, olomoucine, on recovery and peri-infarct changes following photothrombotic stroke. Methods Stroke was induced by photothrombosis in the forelimb sensorimotor cortex in Sprague-Dawley rats. Olomoucine was administered at 1 h and 24 h after stroke induction. Forelimb function was monitored up to 29 days. The effects of olomoucine on glial cell responses in peri-infarct tissue were evaluated using immunohistochemistry and Western blotting. Results Olomoucine treatment did not significantly affect maximal infarct volume. Recovery of the affected forelimb on a placing test was impaired in olomoucine-treated rats, whereas recovery in a skilled reaching test was substantially improved. Olomoucine treatment produced small changes in aspects of Iba1 immunolabelling and in the number of CD68-positive cells in cerebral cortex but did not selectively modify responses in peri-infarct tissue. The content of the astrocytic protein, vimentin, was reduced by 30% in the region of the lesion in olomoucine-treated rats. Conclusions Olomoucine treatment modified functional recovery in the absence of significant changes in infarct volume. The effects on recovery were markedly test dependent, adding to evidence that skilled tasks requiring specific training and general measures of motor function can be differentially modified by some interventions. The altered recovery was not associated with specific changes in key responses of peri-infarct microglia, even though these cells were considered a likely target for early olomoucine treatment. Changes detected in peri-infarct reactive astrogliosis could contribute to the altered patterns of functional recovery. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02208-w.
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Xie W, Gong XT, Cheng X, Cao J, Zhao J, Zhang HL, Zhang S. LIMPID: a versatile method for visualization of brain vascular networks. Biomater Sci 2021; 9:2658-2669. [PMID: 33595547 DOI: 10.1039/d0bm01817a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Visualization of cerebrovascular networks is crucial for understanding the pathogenesis of many neurological diseases. Recently developed optical clearing techniques offer opportunities in deep tissue imaging, and have been successfully applied in many research studies. The development of nanotechnology enables the labeling of brain vessels with functionalized micro/nanoparticles embedded with fluorescent dyes. We herein report an efficient method, named LIMPID (Labeled and Interlinked Micro/nanoparticles for Imaging and Delipidation), specific for the precise fluorescence imaging of vascular networks in clearing-treated tissues. This robust vessel labeling technique replaces conventional fluorescence dyes with functionalized polymer micro/nanoparticles that are able to cross-link with polyacrylamide to form dense hydrogels in vessels. LIMPID shows high-robustness during the clearing process without sacrificing fluorescence signals and clearing performance. LIMPID enables three dimension (3D) visualization of elaborate vascular networks in mouse brains and is compatible with other fluorescence-labeling techniques. We have successfully applied this method to acquire cortical vasculature images simultaneously with the neurons or microglia, as well as to evaluate vascular damage in a mouse model of stroke. The LIMPID method provides a novel tool for the precise analysis of vascular dysfunction and vascular diseases.
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Affiliation(s)
- Wenguang Xie
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou 730000, P. R. China.
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Han B, Jiang W, Cui P, Zheng K, Dang C, Wang J, Li H, Chen L, Zhang R, Wang QM, Ju Z, Hao J. Microglial PGC-1α protects against ischemic brain injury by suppressing neuroinflammation. Genome Med 2021; 13:47. [PMID: 33771213 PMCID: PMC8004413 DOI: 10.1186/s13073-021-00863-5] [Citation(s) in RCA: 101] [Impact Index Per Article: 33.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2020] [Accepted: 03/04/2021] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Neuroinflammation and immune responses occurring minutes to hours after stroke are associated with brain injury after acute ischemic stroke (AIS). PPARγ coactivator-1α (PGC-1α), as a master coregulator of gene expression in mitochondrial biogenesis, was found to be transiently upregulated in microglia after AIS. However, the role of microglial PGC-1α in poststroke immune modulation remains unknown. METHODS PGC-1α expression in microglia from human and mouse brain samples following ischemic stroke was first determined. Subsequently, we employed transgenic mice with microglia-specific overexpression of PGC-1α for middle cerebral artery occlusion (MCAO). The morphology and gene expression profile of microglia with PGC-1α overexpression were evaluated. Downstream inflammatory cytokine production and NLRP3 activation were also determined. ChIP-Seq analysis was performed to detect PGC-1α-binding sites in microglia. Autophagic and mitophagic activity was further monitored by immunofluorescence staining. Unc-51-like autophagy activating kinase 1 (ULK1) expression was evaluated under the PGC-1α interaction with ERRα. Finally, pharmacological inhibition and genomic knockdown of ULK1 were performed to estimate the role of ULK1 in mediating mitophagic activity after ischemic stroke. RESULTS PGC-1α expression was shortly increased after ischemic stroke, not only in human brain samples but also in mouse brain samples. Microglia-specific PGC-1α overexpressing mice exhibited significantly decreased neurologic deficits after ischemic injury, with reduced NLRP3 activation and proinflammatory cytokine production. ChIP-Seq analysis and KEGG pathway analysis revealed that mitophagy was significantly enhanced. PGC-1α significantly promoted autophagic flux and induced autolysosome formation. More specifically, the autophagic clearance of mitochondria was enhanced by PGC-1α regulation, indicating the important role of mitophagy. Pharmacological inhibition or knockdown of ULK1 expression impaired autophagic/mitophagic activity, thus abolishing the neuroprotective effects of PGC-1α. CONCLUSIONS Mechanistically, in AIS, PGC-1α promotes autophagy and mitophagy through ULK1 and reduces NLRP3 activation. Our findings indicate that microglial PGC-1α may be a promising therapeutic target for AIS.
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Affiliation(s)
- Bin Han
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Wei Jiang
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Pan Cui
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Kai Zheng
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Chun Dang
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Junjie Wang
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - He Li
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Lin Chen
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China
| | - Rongxin Zhang
- Laboratory of Immunology and Inflammation, Department of Immunology and Research Center of Basic Medical Sciences, Key Laboratory of Immune Microenvironments and Diseases of Educational Ministry, Tianjin Medical University, Tianjin, 300070, China
| | - Qing Mei Wang
- Stroke Biological Recovery Laboratory, Department of Physical Medicine and Rehabilitation, Spaulding Rehabilitation Hospital, the teaching affiliate of Harvard Medical School Charlestown, Boston, MA, 02129, USA
| | - Zhenyu Ju
- Key Laboratory of Regenerative Medicine of Ministry of Education, Institute of Aging and Regenerative Medicine, Jinan University, Guangzhou, 510632, China
| | - Junwei Hao
- Department of Neurology, Xuanwu Hospital, Capital Medical University, Beijing, 100053, China.
- Department of Neurology, Tianjin Neurological Institute, Tianjin Medical University General Hospital, Tianjin, 300052, China.
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Li T, Zhao J, Xie W, Yuan W, Guo J, Pang S, Gan WB, Gómez-Nicola D, Zhang S. Specific depletion of resident microglia in the early stage of stroke reduces cerebral ischemic damage. J Neuroinflammation 2021; 18:81. [PMID: 33757565 PMCID: PMC7986495 DOI: 10.1186/s12974-021-02127-w] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2020] [Accepted: 03/11/2021] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Ischemia can induce rapid activation of microglia in the brain. As key immunocompetent cells, reactive microglia play an important role in pathological development of ischemic stroke. However, the role of activated microglia during the development of ischemia remains controversial. Thus, we aimed to investigate the function of reactive microglia in the early stage of ischemic stroke. METHODS A Rose Bengal photothrombosis model was applied to induce targeted ischemic stroke in mice. CX3CR1CreER:R26iDTR mice were used to specifically deplete resident microglia through intragastric administration of tamoxifen (Ta) and intraperitoneal injection of diphtheria toxin (DT). At day 3 after ischemic stroke, behavioral tests were performed. After that, mouse brains were collected for further histological analysis and detection of mRNA expression of inflammatory factors. RESULTS The results showed that specific depletion of microglia resulted in a significant decrease in ischemic infarct volume and improved performance in motor ability 3 days after stroke. Microglial depletion caused a remarkable reduction in the densities of degenerating neurons and inducible nitric oxide synthase positive (iNOS+) cells. Importantly, depleting microglia induced a significant increase in the mRNA expression level of anti-inflammatory factors TGF-β1, Arg1, IL-10, IL-4, and Ym1 as well as a significant decline of pro-inflammatory factors TNF-α, iNOS, and IL-1β 3 days after stroke. CONCLUSIONS These results suggest that activated microglia is an important modulator of the brain's inflammatory response in stroke, contributing to neurological deficit and infarct expansion. Modulation of the inflammatory response through the elimination of microglia at a precise time point may be a promising therapeutic approach for the treatment of cerebral ischemia.
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Affiliation(s)
- Ting Li
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, People's Republic of China
| | - Jin Zhao
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, People's Republic of China
| | - Wenguang Xie
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, People's Republic of China
| | - Wanru Yuan
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, People's Republic of China
| | - Jing Guo
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, People's Republic of China
| | - Shengru Pang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, People's Republic of China
| | - Wen-Biao Gan
- Molecular Neurobiology Program, The Kimmel Center for Biology and Medicine of the Skirball Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, 10016, USA.
| | - Diego Gómez-Nicola
- Centre for Biological Sciences, University of Southampton, South Lab and Path Block, Mail Point 840 LD80C, Southampton General Hospital, Tremona Road, Southampton, SO16 6YD, UK.
| | - Shengxiang Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, No. 222 South Tianshui Road, Lanzhou, Gansu, 730000, People's Republic of China.
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60
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Roth S, Cao J, Singh V, Tiedt S, Hundeshagen G, Li T, Boehme JD, Chauhan D, Zhu J, Ricci A, Gorka O, Asare Y, Yang J, Lopez MS, Rehberg M, Bruder D, Zhang S, Groß O, Dichgans M, Hornung V, Liesz A. Post-injury immunosuppression and secondary infections are caused by an AIM2 inflammasome-driven signaling cascade. Immunity 2021; 54:648-659.e8. [PMID: 33667383 DOI: 10.1016/j.immuni.2021.02.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Revised: 12/16/2020] [Accepted: 02/08/2021] [Indexed: 01/01/2023]
Abstract
Loss of lymphocytes, particularly T cell apoptosis, is a central pathological event after severe tissue injury that is associated with increased susceptibility for life-threatening infections. The precise immunological mechanisms leading to T cell death after acute injury are largely unknown. Here, we identified a monocyte-T cell interaction driving bystander cell death of T cells in ischemic stroke and burn injury. Specifically, we found that stroke induced a FasL-expressing monocyte population, which led to extrinsic T cell apoptosis. This phenomenon was driven by AIM2 inflammasome-dependent interleukin-1β (IL-1β) secretion after sensing cell-free DNA. Pharmacological inhibition of this pathway improved T cell survival and reduced post-stroke bacterial infections. As such, this study describes inflammasome-dependent monocyte activation as a previously unstudied cause of T cell death after injury and challenges the current paradigms of post-injury lymphopenia.
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Affiliation(s)
- Stefan Roth
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany
| | - Jiayu Cao
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany
| | - Vikramjeet Singh
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany
| | - Steffen Tiedt
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Gabriel Hundeshagen
- Department of Hand-, Plastic and Reconstructive Surgery, Burn Center, BG Trauma Center Ludwigshafen, University of Heidelberg, Ludwigshafen, Germany
| | - Ting Li
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Julia D Boehme
- Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany; Infection Immunology, Institute of Medical Microbiology, Infection Control and Prevention, Health Campus Immunology, Infectiology and Inflammation, Otto von-Guericke University, Magdeburg, Germany
| | - Dhruv Chauhan
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Jie Zhu
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany
| | - Alessio Ricci
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany
| | - Oliver Gorka
- Institute of Neuropathology, Medical Center, University of Freiburg, Freiburg, Germany
| | - Yaw Asare
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany
| | - Jun Yang
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany
| | - Mary S Lopez
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany
| | - Markus Rehberg
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany
| | - Dunja Bruder
- Immune Regulation, Helmholtz Centre for Infection Research, Braunschweig, Germany; Infection Immunology, Institute of Medical Microbiology, Infection Control and Prevention, Health Campus Immunology, Infectiology and Inflammation, Otto von-Guericke University, Magdeburg, Germany
| | - Shengxiang Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Olaf Groß
- Institute of Neuropathology, Medical Center, University of Freiburg, Freiburg, Germany; Signalling Research Centres BIOSS and CIBSS, Freiburg, Germany; Center for Basics in NeuroModulation (NeuroModulBasics), Freiburg, Germany
| | - Martin Dichgans
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Veit Hornung
- Gene Center and Department of Biochemistry, Ludwig-Maximilians-Universität München, Munich, Germany
| | - Arthur Liesz
- Institute for Stroke and Dementia Research (ISD), University Hospital, LMU Munich, Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.
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61
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Subedi L, Gaire BP. Phytochemicals as regulators of microglia/macrophages activation in cerebral ischemia. Pharmacol Res 2021; 165:105419. [DOI: 10.1016/j.phrs.2021.105419] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Revised: 12/16/2020] [Accepted: 01/02/2021] [Indexed: 12/12/2022]
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62
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Jiang Y, Müller K, Khan MA, Assmann JC, Lampe J, Kilau K, Richter M, Kleint M, Ridder DA, Hübner N, Schmidt-Supprian M, Wenzel J, Schwaninger M. Cerebral angiogenesis ameliorates pathological disorders in Nemo-deficient mice with small-vessel disease. J Cereb Blood Flow Metab 2021; 41:219-235. [PMID: 32151223 PMCID: PMC8369998 DOI: 10.1177/0271678x20910522] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Cerebral small-vessel diseases (SVDs) often follow a progressive course. Little is known about the function of angiogenesis, which potentially induces regression of SVDs. Here, we investigated angiogenesis in a mouse model of incontinentia pigmenti (IP), a genetic disease comprising features of SVD. IP is caused by inactivating mutations of Nemo, the essential component of NF-κB signaling. When deleting Nemo in the majority of brain endothelial cells (NemobeKO mice), the transcriptional profile of vessels indicated cell proliferation. Brain endothelial cells expressed Ki67 and showed signs of DNA synthesis. In addition to cell proliferation, we observed sprouting and intussusceptive angiogenesis in NemobeKO mice. Angiogenesis occurred in all segments of the vasculature and in proximity to vessel rarefaction and tissue hypoxia. Apparently, NEMO was required for productive angiogenesis because endothelial cells that had escaped Nemo inactivation showed a higher proliferation rate than Nemo-deficient cells. Therefore, newborn endothelial cells were particularly vulnerable to ongoing recombination. When we interfered with productive angiogenesis by inducing ongoing ablation of Nemo, mice did not recover from IP manifestations but rather showed severe functional deficits. In summary, the data demonstrate that angiogenesis is present in this model of SVD and suggest that it may counterbalance the loss of vessels.
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Affiliation(s)
- Yun Jiang
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Kristin Müller
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Mahtab A Khan
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Julian C Assmann
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Josephine Lampe
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany.,DZHK (German Research Centre for Cardiovascular Research), Germany
| | - Knut Kilau
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany.,DZHK (German Research Centre for Cardiovascular Research), Germany
| | - Marius Richter
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Maximilian Kleint
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Dirk A Ridder
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany
| | - Norbert Hübner
- DZHK (German Research Centre for Cardiovascular Research), Germany.,Max-Delbrück Center for Molecular Medicine, Berlin, Germany.,Charité-Universitätsmedizin Berlin, Charitéplatz 1, Berlin, Germany
| | - Marc Schmidt-Supprian
- Institute of Experimental Hematology, Klinikum Rechts der Isar, Technische Universität München, Munich, Germany
| | - Jan Wenzel
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany.,DZHK (German Research Centre for Cardiovascular Research), Germany
| | - Markus Schwaninger
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Lübeck, Germany.,DZHK (German Research Centre for Cardiovascular Research), Germany
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63
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Baidya F, Bohra M, Datta A, Sarmah D, Shah B, Jagtap P, Raut S, Sarkar A, Singh U, Kalia K, Borah A, Wang X, Dave KR, Yavagal DR, Bhattacharya P. Neuroimmune crosstalk and evolving pharmacotherapies in neurodegenerative diseases. Immunology 2021; 162:160-178. [PMID: 32939758 PMCID: PMC7808166 DOI: 10.1111/imm.13264] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 08/20/2020] [Accepted: 08/29/2020] [Indexed: 02/06/2023] Open
Abstract
Neurodegeneration is characterized by gradual onset and limited availability of specific biomarkers. Apart from various aetiologies such as infection, trauma, genetic mutation, the interaction between the immune system and CNS is widely associated with neuronal damage in neurodegenerative diseases. The immune system plays a distinct role in disease progression and cellular homeostasis. It induces cellular and humoral responses, and enables tissue repair, cellular healing and clearance of cellular detritus. Aberrant and chronic activation of the immune system can damage healthy neurons. The pro-inflammatory mediators secreted by chief innate immune components, the complement system, microglia and inflammasome can augment cytotoxicity. Furthermore, these inflammatory mediators accelerate microglial activation resulting in progressive neuronal loss. Various animal studies have been carried out to unravel the complex pathology and ascertain biomarkers for these harmful diseases, but have had limited success. The present review will provide a thorough understanding of microglial activation, complement system and inflammasome generation, which lead the healthy brain towards neurodegeneration. In addition to this, possible targets of immune components to confer a strategic treatment regime for the alleviation of neuronal damage are also summarized.
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Affiliation(s)
- Falguni Baidya
- Department of Pharmacology and ToxicologyNational Institute of Pharmaceutical Education and Research, Ahmedabad (NIPER‐A)GandhinagarGujaratIndia
| | - Mariya Bohra
- Department of Pharmacology and ToxicologyNational Institute of Pharmaceutical Education and Research, Ahmedabad (NIPER‐A)GandhinagarGujaratIndia
| | - Aishika Datta
- Department of Pharmacology and ToxicologyNational Institute of Pharmaceutical Education and Research, Ahmedabad (NIPER‐A)GandhinagarGujaratIndia
| | - Deepaneeta Sarmah
- Department of Pharmacology and ToxicologyNational Institute of Pharmaceutical Education and Research, Ahmedabad (NIPER‐A)GandhinagarGujaratIndia
| | - Birva Shah
- Department of Pharmacology and ToxicologyNational Institute of Pharmaceutical Education and Research, Ahmedabad (NIPER‐A)GandhinagarGujaratIndia
| | - Priya Jagtap
- Department of Pharmacology and ToxicologyNational Institute of Pharmaceutical Education and Research, Ahmedabad (NIPER‐A)GandhinagarGujaratIndia
| | - Swapnil Raut
- Department of Pharmacology and ToxicologyNational Institute of Pharmaceutical Education and Research, Ahmedabad (NIPER‐A)GandhinagarGujaratIndia
| | - Ankan Sarkar
- Department of Pharmacology and ToxicologyNational Institute of Pharmaceutical Education and Research, Ahmedabad (NIPER‐A)GandhinagarGujaratIndia
| | - Upasna Singh
- Department of Pharmacology and ToxicologyNational Institute of Pharmaceutical Education and Research, Ahmedabad (NIPER‐A)GandhinagarGujaratIndia
| | - Kiran Kalia
- Department of Pharmacology and ToxicologyNational Institute of Pharmaceutical Education and Research, Ahmedabad (NIPER‐A)GandhinagarGujaratIndia
| | - Anupom Borah
- Department of Life Science and BioinformaticsAssam UniversitySilcharAssamIndia
| | - Xin Wang
- Department of NeurosurgeryBrigham and Women’s HospitalHarvard Medical SchoolBostonMAUSA
| | - Kunjan R. Dave
- Department of NeurologyUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Dileep R. Yavagal
- Department of Neurology and NeurosurgeryUniversity of Miami Miller School of MedicineMiamiFLUSA
| | - Pallab Bhattacharya
- Department of Pharmacology and ToxicologyNational Institute of Pharmaceutical Education and Research, Ahmedabad (NIPER‐A)GandhinagarGujaratIndia
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64
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Aliena-Valero A, Rius-Pérez S, Baixauli-Martín J, Torregrosa G, Chamorro Á, Pérez S, Salom JB. Uric Acid Neuroprotection Associated to IL-6/STAT3 Signaling Pathway Activation in Rat Ischemic Stroke. Mol Neurobiol 2021; 58:408-423. [PMID: 32959172 DOI: 10.1007/s12035-020-02115-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Accepted: 09/02/2020] [Indexed: 12/21/2022]
Abstract
Despite the promising neuroprotective effects of uric acid (UA) in acute ischemic stroke, the seemingly pleiotropic underlying mechanisms are not completely understood. Recent evidence points to transcription factors as UA targets. To gain insight into the UA mechanism of action, we investigated its effects on pertinent biomarkers for the most relevant features of ischemic stroke pathophysiology: (1) oxidative stress (antioxidant enzyme mRNAs and MDA), (2) neuroinflammation (cytokine and Socs3 mRNAs, STAT3, NF-κB p65, and reactive microglia), (3) brain swelling (Vegfa, Mmp9, and Timp1 mRNAs), and (4) apoptotic cell death (Bcl-2, Bax, caspase-3, and TUNEL-positive cells). Adult male Wistar rats underwent intraluminal filament transient middle cerebral artery occlusion (tMCAO) and received UA (16 mg/kg) or vehicle (Locke's buffer) i.v. at 20 min reperfusion. The outcome measures were neurofunctional deficit, infarct, and edema. UA treatment reduced cortical infarct and brain edema, as well as neurofunctional impairment. In brain cortex, increased UA: (1) reduced tMCAO-induced increases in Vegfa and Mmp9/Timp1 ratio expressions; (2) induced Sod2 and Cat expressions and reduced MDA levels; (3) induced Il6 expression, upregulated STAT3 and NF-κB p65 phosphorylation, induced Socs3 expression, and inhibited microglia activation; and (4) ameliorated the Bax/Bcl-2 ratio and induced a reduction in caspase-3 cleavage as well as in TUNEL-positive cell counts. In conclusion, the mechanism for morphological and functional neuroprotection by UA in ischemic stroke is multifaceted, since it is associated to activation of the IL-6/STAT3 pathway, attenuation of edematogenic VEGF-A/MMP-9 signaling, and modulation of relevant mediators of oxidative stress, neuroinflammation, and apoptotic cell death.
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Affiliation(s)
- Alicia Aliena-Valero
- Unidad Mixta de Investigación Cerebrovascular, Instituto de Investigación Sanitaria La Fe - Universitat de València, Torre A, Lab 5.05, Ave Fernando Abril Martorell 106, 46026, Valencia, Spain
- Departamento de Fisiología, Facultad de Farmacia, Universitat de València, Ave Vicent Andrés Estellés s/n, Burjassot, 46100, Valencia, Spain
| | - Sergio Rius-Pérez
- Departamento de Fisiología, Facultad de Farmacia, Universitat de València, Ave Vicent Andrés Estellés s/n, Burjassot, 46100, Valencia, Spain
| | - Júlia Baixauli-Martín
- Departamento de Fisiología, Facultad de Farmacia, Universitat de València, Ave Vicent Andrés Estellés s/n, Burjassot, 46100, Valencia, Spain
| | - Germán Torregrosa
- Unidad Mixta de Investigación Cerebrovascular, Instituto de Investigación Sanitaria La Fe - Universitat de València, Torre A, Lab 5.05, Ave Fernando Abril Martorell 106, 46026, Valencia, Spain
| | - Ángel Chamorro
- Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Comprehensive Stroke Center, Department of Neuroscience, Hospital Clinic, Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS), Barcelona, Spain
- Departamento de Medicina, Universitat de Barcelona, Barcelona, Spain
| | - Salvador Pérez
- Departamento de Fisiología, Facultad de Farmacia, Universitat de València, Ave Vicent Andrés Estellés s/n, Burjassot, 46100, Valencia, Spain.
| | - Juan B Salom
- Unidad Mixta de Investigación Cerebrovascular, Instituto de Investigación Sanitaria La Fe - Universitat de València, Torre A, Lab 5.05, Ave Fernando Abril Martorell 106, 46026, Valencia, Spain.
- Departamento de Fisiología, Facultad de Farmacia, Universitat de València, Ave Vicent Andrés Estellés s/n, Burjassot, 46100, Valencia, Spain.
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65
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Liang Y, Walczak P. Long term intravital single cell tracking under multiphoton microscopy. J Neurosci Methods 2020; 349:109042. [PMID: 33340557 DOI: 10.1016/j.jneumeth.2020.109042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/07/2020] [Accepted: 12/11/2020] [Indexed: 12/13/2022]
Abstract
Visualizing and tracking cells over time in a living organism has been a much-coveted dream before the invention of intravital microscopy. The opaque nature of tissue was a major hurdle that was remedied by the multiphoton microscopy. With the advancement of optical imaging and fluorescent labeling tools, intravital high resolution imaging has become increasingly accessible over the past few years. Long-term intravital tracking of single cells (LIST) under multiphoton microscopy provides a unique opportunity to gain insight into the longitudinal changes in the morphology, migration, or function of cells or subcellular structures. It is particularly suitable for studying slow-evolving cellular and molecular events during normal development or disease progression, without losing the opportunity of catching fast events such as calcium signals. Here, we review the application of LIST under 2-photon microscopy in various fields of neurobiology and discuss challenges and new directions in labeling and imaging methods for LIST. Overall, this review provides an overview of current applications of LIST in mammals, which is an emerging field that will contribute to a better understanding of essential molecular and cellular events in health and disease.
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Affiliation(s)
- Yajie Liang
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Piotr Walczak
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
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66
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Lubart A, Benbenishty A, Har-Gil H, Laufer H, Gdalyahu A, Assaf Y, Blinder P. Single Cortical Microinfarcts Lead to Widespread Microglia/Macrophage Migration Along the White Matter. Cereb Cortex 2020; 31:248-266. [PMID: 32954425 DOI: 10.1093/cercor/bhaa223] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2018] [Revised: 05/13/2020] [Accepted: 06/08/2020] [Indexed: 12/31/2022] Open
Abstract
Loss of cognitive function with aging is a complex and poorly understood process. Recently, clinical research has linked the occurrence of cortical microinfarcts to cognitive decline. Cortical microinfarcts form following the occlusion of penetrating vessels and are considered to be restricted to the proximity of the occluded vessel. Whether and how such local events propagate and affect remote brain regions remain unknown. To this end, we combined histological analysis and longitudinal diffusion tensor imaging (DTI), following the targeted-photothrombotic occlusion of single cortical penetrating vessels. Occlusions resulted in distant tissue reorganization across the mouse brain. This remodeling co-occurred with the formation of a microglia/macrophage migratory path along subcortical white matter tracts, reaching the contralateral hemisphere through the corpus callosum and leaving a microstructural signature detected by DTI-tractography. CX3CR1-deficient mice exhibited shorter trail lengths, differential remodeling, and only ipsilateral white matter tract changes. We concluded that microinfarcts lead to brain-wide remodeling in a microglial CX3CR1-dependent manner.
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Affiliation(s)
- Alisa Lubart
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Amit Benbenishty
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel.,Biological Regulation Department, The Weizmann Institute of Science, Rehovot, Israel
| | - Hagai Har-Gil
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Hadas Laufer
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Amos Gdalyahu
- Neurobiology, Biochemistry and Biophysics School, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Yaniv Assaf
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel.,Neurobiology, Biochemistry and Biophysics School, Tel Aviv University, Tel Aviv-Yafo, Israel
| | - Pablo Blinder
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv-Yafo, Israel.,Neurobiology, Biochemistry and Biophysics School, Tel Aviv University, Tel Aviv-Yafo, Israel
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67
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Acute brain injuries trigger microglia as an additional source of the proteoglycan NG2. Acta Neuropathol Commun 2020; 8:146. [PMID: 32843103 PMCID: PMC7449013 DOI: 10.1186/s40478-020-01016-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 08/10/2020] [Indexed: 01/07/2023] Open
Abstract
NG2 is a type I transmembrane glycoprotein known as chondroitin sulfate proteoglycan 4 (CSPG4). In the healthy central nervous system, NG2 is exclusively expressed by oligodendrocyte progenitor cells and by vasculature pericytes. A large body of immunohistochemical studies showed that under pathological conditions such as acute brain injuries and experimental autoimmune encephalomyelitis (EAE), a number of activated microglia were NG2 immuno-positive, suggesting NG2 expression in these cells. Alternative explanations for the microglial NG2 labeling consider the biochemical properties of NG2 or the phagocytic activity of activated microglia. Reportedly, the transmembrane NG2 proteoglycan can be cleaved by a variety of proteases to deposit the NG2 ectodomain into the extracellular matrix. The ectodomain, however, could also stick to the microglial surface. Since microglia are phagocytic cells engulfing debris of dying cells, it is difficult to identify a genuine expression of NG2. Recent studies showing (1) pericytes giving rise to microglial after stroke, and (2) immune cells of NG2-EYFP knock-in mice lacking NG2 expression in an EAE model generated doubts for the de novo expression of NG2 in microglia after acute brain injuries. In the current study, we took advantage of three knock-in mouse lines (NG2-CreERT2, CX3CR1-EGFP and NG2-EYFP) to study NG2 expression indicated by transgenic fluorescent proteins in microglia after tMCAO (transient middle cerebral artery occlusion) or cortical stab wound injury (SWI). We provide strong evidence that NG2-expressing cells, including OPCs and pericytes, did not differentiate into microglia after acute brain injuries, whereas activated microglia did express NG2 in a disease-dependent manner. A subset of microglia continuously activated the NG2 gene at least within the first week after tMCAO, whereas within 3 days after SWI a limited number of microglia at the lesion site transiently expressed NG2. Immunohistochemical studies demonstrated that these microglia with NG2 gene activity also synthesized the NG2 protein, suggesting activated microglia as an additional source of the NG2 proteoglycan after acute brain injuries.
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68
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Ma M, Wang Z, Wang J, Wei S, Cui J, Wang Y, Luo K, Zhao L, Liu X, Wang R. Endomorphin analog exhibited superiority in alleviating neuropathic hyperalgesia via weak activation of NMDA receptors. J Neurochem 2020; 155:662-678. [DOI: 10.1111/jnc.15127] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 06/10/2020] [Accepted: 07/11/2020] [Indexed: 12/20/2022]
Affiliation(s)
- Mengtao Ma
- Department of Pharmacology Key Laboratory of Preclinical Study for New Drugs of Gansu Province Institute of Biochemistry and Molecular BiologySchool of Basic Medical SciencesLanzhou University Lanzhou China
| | - Zhaojuan Wang
- Department of Pharmacology Key Laboratory of Preclinical Study for New Drugs of Gansu Province Institute of Biochemistry and Molecular BiologySchool of Basic Medical SciencesLanzhou University Lanzhou China
| | - Jing Wang
- Department of Pharmacology Key Laboratory of Preclinical Study for New Drugs of Gansu Province Institute of Biochemistry and Molecular BiologySchool of Basic Medical SciencesLanzhou University Lanzhou China
| | - Shuang Wei
- Department of Pharmacology Key Laboratory of Preclinical Study for New Drugs of Gansu Province Institute of Biochemistry and Molecular BiologySchool of Basic Medical SciencesLanzhou University Lanzhou China
| | - Jiaming Cui
- Department of Pharmacology Key Laboratory of Preclinical Study for New Drugs of Gansu Province Institute of Biochemistry and Molecular BiologySchool of Basic Medical SciencesLanzhou University Lanzhou China
| | - Yuan Wang
- Department of Pharmacology Key Laboratory of Preclinical Study for New Drugs of Gansu Province Institute of Biochemistry and Molecular BiologySchool of Basic Medical SciencesLanzhou University Lanzhou China
| | - Keyao Luo
- Department of Pharmacology Key Laboratory of Preclinical Study for New Drugs of Gansu Province Institute of Biochemistry and Molecular BiologySchool of Basic Medical SciencesLanzhou University Lanzhou China
| | - Long Zhao
- Department of Pharmacology Key Laboratory of Preclinical Study for New Drugs of Gansu Province Institute of Biochemistry and Molecular BiologySchool of Basic Medical SciencesLanzhou University Lanzhou China
| | - Xin Liu
- Department of Pharmacology Key Laboratory of Preclinical Study for New Drugs of Gansu Province Institute of Biochemistry and Molecular BiologySchool of Basic Medical SciencesLanzhou University Lanzhou China
| | - Rui Wang
- Department of Pharmacology Key Laboratory of Preclinical Study for New Drugs of Gansu Province Institute of Biochemistry and Molecular BiologySchool of Basic Medical SciencesLanzhou University Lanzhou China
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69
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Orofacial skin inflammation increases the number of macrophages in the maxillary subregion of the rat trigeminal ganglion in a corticosteroid-reversible manner. Cell Tissue Res 2020; 382:551-561. [PMID: 32696216 PMCID: PMC7683439 DOI: 10.1007/s00441-020-03244-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Accepted: 06/15/2020] [Indexed: 10/25/2022]
Abstract
Inflammation of the cutaneous orofacial tissue can lead to a prolonged alteration of neuronal and nonneuronal cellular functions in trigeminal nociceptive pathways. In this study, we investigated the effects of experimentally induced skin inflammation by dithranol (anthralin) on macrophage activation in the rat trigeminal ganglion. Tissue localization and protein expression levels of ionized calcium-binding adaptor molecule 1 (Iba1), a macrophage/microglia-specific marker, and proliferation/mitotic marker antigen identified by the monoclonal antibody Ki67 (Ki67), were quantitatively analyzed using immunohistochemistry and western blots in control, dithranol-treated, dithranol- and corticosteroid-treated, and corticosteroid-treated trigeminal ganglia. Chronic orofacial dithranol treatment elicited a strong pro-inflammatory effect in the ipsilateral trigeminal ganglion. Indeed, daily dithranol treatment of the orofacial skin for 3-5 days increased the number of macrophages and Iba1 protein expression in the maxillary subregion of the ipsilateral ganglion. In the affected ganglia, none of the Iba1-positive cells expressed Ki67. This absence of mitotically active cells suggested that the accumulation of macrophages in the ganglion was not the result of resident microglia proliferation but rather the extravasation of hematogenous monocytes from the periphery. Subsequently, when a 5-day-long anti-inflammatory corticosteroid therapy was employed on the previously dithranol-treated orofacial skin, Iba1 immunoreactivity was substantially reduced in the ipsilateral ganglion. Collectively, our findings indicate that both peripheral inflammation and subsequent anti-inflammatory therapy affect macrophage activity and thus interfere with the functioning of the affected sensory ganglion neurons.
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70
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Yu L, Su X, Li S, Zhao F, Mu D, Qu Y. Microglia and Their Promising Role in Ischemic Brain Injuries: An Update. Front Cell Neurosci 2020; 14:211. [PMID: 32754016 PMCID: PMC7365911 DOI: 10.3389/fncel.2020.00211] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2020] [Accepted: 06/16/2020] [Indexed: 12/14/2022] Open
Abstract
Ischemic brain injuries are common diseases with high morbidity, disability, and mortality rates, which have significant impacts on human health and life. Microglia are resident cells of the central nervous system (CNS). The inflammatory responses mediated by microglia play an important role in the occurrence and development of ischemic brain injuries. This article summarizes the activation, polarization, depletion, and repopulation of microglia after ischemic brain injuries, proposing new treatment strategies for such injuries through the modulation of microglial function.
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Affiliation(s)
- Luting Yu
- Department of Paediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
| | - Xiaojuan Su
- Department of Paediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
| | - Shiping Li
- Department of Paediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
| | - Fengyan Zhao
- Department of Paediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
| | - Dezhi Mu
- Department of Paediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
| | - Yi Qu
- Department of Paediatrics, West China Second University Hospital, Sichuan University, Chengdu, China.,Key Laboratory of Birth Defects and Related Diseases of Women and Children, Sichuan University, Ministry of Education, Chengdu, China
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71
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Retinal ischemia triggers early microglia activation in the optic nerve followed by neurofilament degeneration. Exp Eye Res 2020; 198:108133. [PMID: 32645332 DOI: 10.1016/j.exer.2020.108133] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 05/14/2020] [Accepted: 06/29/2020] [Indexed: 12/12/2022]
Abstract
Retinal ischemia leads to an early severe damage of the retina and thus plays an important role in eye diseases such as angle-closure glaucoma or retinal vascular occlusion. In retinal diseases, there is common sense about the affection of the optic nerve by ischemic injury. However, the exact dynamic processes of this optic nerve degeneration are mainly unclear. In this study, retinal ischemia was induced in one eye of Brown-Norway rats by raising the intraocular pressure 60 min to 140 mmHg followed by natural reperfusion. Optic nerves were analyzed at six different points in time: 2, 6, 12, and 24 h as well as 3 and 7 days after ischemic injury. Cell infiltration and moreover signs of tissue demyelination and dissolution were noticed in optic nerves 7 days after ischemia (hematoxylin & eosin: p < 0.001, luxol fast blue: p = 0.04). Although microglial activation was verified already from 12 h on after ischemia (p = 0.030), the beginning of a structural degeneration of the neurofilament was seen at 3 days (p = 0.02). Interestingly, proliferative microglia were present later on (7 days: p = 0.017). At this point, the number of total microglia was also increased in ischemic nerves (p = 0.003). Concluding, our data indicate that not only retinal tissue is affected by an ischemia, the optic nerve also demonstrates progressive damage. Interestingly, a microglia activation was noted days before structural damage became visible.
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72
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Cranial irradiation acutely and persistently impairs injury-induced microglial proliferation. Brain Behav Immun Health 2020; 4:100057. [PMID: 34589843 PMCID: PMC8474291 DOI: 10.1016/j.bbih.2020.100057] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2020] [Revised: 02/28/2020] [Accepted: 03/01/2020] [Indexed: 12/12/2022] Open
Abstract
Microglia, the resident immune cells of the central nervous system (CNS), play multiple roles in maintaining CNS homeostasis and mediating tissue repair, including proliferating in response to brain injury and disease. Cranial irradiation (CI), used for the treatment of brain tumors, has a long-lasting anti-proliferative effect on a number of cell types in the brain, including oligodendrocyte progenitor and neural progenitor cells; however, the effect of CI on CNS-resident microglial proliferation is not well characterized. Using a sterile cortical needle stab injury model in mice, we found that the ability of CNS-resident microglia to proliferate in response to injury was impaired by prior CI, in a dose-dependent manner, and was nearly abolished by a 20 Gy dose. Similarly, in a metastatic tumor model, prior CI (20 Gy) reduced microglial proliferation in response to tumor growth. The effect of irradiation was long-lasting; 20 Gy CI 6 months prior to stab injury significantly impaired microglial proliferation. We also investigated how stab and/or irradiation impacted levels of P2Y12R, CD68, CSF1, IL-34 and CSF1R, factors involved in the brain’s normal response to injury. P2Y12R, CD68, CSF1, and IL-34 expression were altered by stab similarly in irradiated mice and controls; however, CSF1R was differentially affected. qRT-PCR and flow cytometry analyses demonstrated that CI reduced overall Csf1r mRNA levels and microglial specific CSF1R protein expression, respectively. Interestingly, Csf1r mRNA levels increased after injury in unirradiated controls; however, Csf1r levels were persistently decreased in irradiated mice, and did not increase in response to stab. Together, our data demonstrate that CI leads to a significant and lasting impairment of microglial proliferation, possibly through a CSF1R-mediated mechanism. Irradiation leads to a long-term deficit in injury-induced microglial proliferation. Irradiation reduces microglial proliferation associated with tumor growth. Irradiation decreases microglial CSF1R and prevents its upregulation after injury.
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73
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Sun X, Wang Z, Wu Q, Jin S, Yao J, Cheng H. LncRNA RMST activates TAK1‐mediated NF‐κB signaling and promotes activation of microglial cells via competitively binding with hnRNPK. IUBMB Life 2019; 71:1785-1793. [PMID: 31329361 DOI: 10.1002/iub.2125] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2019] [Accepted: 06/26/2019] [Indexed: 12/29/2022]
Affiliation(s)
- Xiu‐Lan Sun
- Neuroprotective Drug Discovery Key Laboratory of Nanjing Medical University; Jiangsu Key Laboratory of Neurodegeneration; Department of PharmacologyNanjing Medical University Nanjing Jiangsu China
| | - Zhao‐Lu Wang
- Department of NeurologyFirst Affiliated Hospital of Nanjing Medical University Nanjing Jiangsu China
| | - Qian Wu
- Department of NeurologyFirst Affiliated Hospital of Nanjing Medical University Nanjing Jiangsu China
| | - Shan‐Quan Jin
- Department of NeurologyFirst Affiliated Hospital of Nanjing Medical University Nanjing Jiangsu China
| | - Juan Yao
- Department of NeurologyFirst Affiliated Hospital of Nanjing Medical University Nanjing Jiangsu China
| | - Hong Cheng
- Department of NeurologyFirst Affiliated Hospital of Nanjing Medical University Nanjing Jiangsu China
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74
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Zhang S. Microglial activation after ischaemic stroke. Stroke Vasc Neurol 2019; 4:71-74. [PMID: 31338213 PMCID: PMC6613941 DOI: 10.1136/svn-2018-000196] [Citation(s) in RCA: 82] [Impact Index Per Article: 16.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 04/16/2019] [Accepted: 04/23/2019] [Indexed: 12/16/2022] Open
Abstract
Ischaemic stroke can induce rapid activation of microglia. As the resident immune cells of the central nervous system, microglial activation is believed to play a central role in neuroinflammation and pathological progression of ischaemic tissue. The activation of microglia after ischaemia involves several stereotypical events including morphological transformation, proliferation and polarisation. Studies using confocal or two-photon imaging techniques have revealed that the degree of microglial activation is correlated with the degree of ischaemia. Activated microglia display diverse polarisation phenotypes. It remains largely unclear regarding whether activated microglia are beneficial or detrimental to poststroke recovery. This mini-review focuses on the morphological and functional aspects of microglial activation, with particular attention to progress in two-photon imaging studies.
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Affiliation(s)
- Shengxiang Zhang
- Gansu Key Laboratory of Biomonitoring and Bioremediation for Environmental Pollution, School of Life Sciences, Lanzhou University, Lanzhou, China
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75
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Zhang X, Zhu XL, Ji BY, Cao X, Yu LJ, Zhang Y, Bao XY, Xu Y, Jin JL. LncRNA-1810034E14Rik reduces microglia activation in experimental ischemic stroke. J Neuroinflammation 2019; 16:75. [PMID: 30961627 PMCID: PMC6452518 DOI: 10.1186/s12974-019-1464-x] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Accepted: 03/26/2019] [Indexed: 12/30/2022] Open
Abstract
Background Activation of microglial cells plays an important role in neuroinflammation after ischemic stroke. Inhibiting the activation of microglial cells has been suggested as a potential therapeutic approach in the treatment of ischemic stroke. Methods Oxygen-glucose deprivation in primary microglial cells and transient middle cerebral artery occlusion (MCAO) in C57BL/6 mice were used as the in vitro and in vivo ischemic stroke models. Microarray analysis was performed to investigate the overall impact of long non-coding RNAs (lncRNAs) on the inflammation status of microglial cells. RT-qPCR was used to evaluate the lncRNA levels and mRNA levels of cytokines and microglial cell markers. ELISA was taken to measure the level of cytokines. Immunofluorescence was used to observe the activation of microglial cells. Western blotting was performed to test the p65 phosphorylation. Results In this study, we showed that LncRNA-1810034E14Rik was significantly decreased in LPS-treated or oxygen-glucose deprivation-induced microglial cells. Overexpression of 1810034E14Rik decreased the infarct volume and alleviated brain damage in MCAO mice. 1810034E14Rik overexpression reduced the expression of inflammatory cytokines not only in ischemic stroke mice but also in oxygen-glucose deprivation-induced microglial cells. Moreover, 1810034E14Rik overexpression could suppress the activation of microglial cells and inhibit the phosphorylation of p65. Conclusions LncRNA-1810034E14Rik plays an anti-inflammatory role in ischemic stroke and regulates p65 phosphorylation, making it a potential target for stroke treatment. Electronic supplementary material The online version of this article (10.1186/s12974-019-1464-x) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Xi Zhang
- Department of Neurology, Drum Tower Hospital, Medical School and The State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, 210008, China.,Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, 210008, China
| | - Xiao-Lei Zhu
- Department of Neurology, Drum Tower Hospital, Medical School and The State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, 210008, China.,Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, 210008, China
| | - Bi-Ying Ji
- Department of Neurology, Drum Tower Hospital, Medical School and The State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, 210008, China.,Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, 210008, China
| | - Xiang Cao
- Department of Neurology, Drum Tower Hospital, Medical School and The State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, 210008, China.,Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, 210008, China
| | - Lin-Jie Yu
- Department of Neurology, Drum Tower Hospital, Medical School and The State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, 210008, China.,Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, 210008, China
| | - Yan Zhang
- Department of Neurology, Drum Tower Hospital, Medical School and The State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, 210008, China.,Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, 210008, China
| | - Xin-Yu Bao
- Department of Neurology, Drum Tower Hospital, Medical School and The State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, 210008, China.,Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, 210008, China
| | - Yun Xu
- Department of Neurology, Drum Tower Hospital, Medical School and The State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, 210008, China. .,Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, 210008, China. .,Jiangsu Province Stroke Center for Diagnosis and Therapy, Nanjing, 210008, China. .,Nanjing Neuropsychiatry Clinic Medical Center, Nanjing, 210008, China.
| | - Jia-Li Jin
- Department of Neurology, Drum Tower Hospital, Medical School and The State Key Laboratory of Pharmaceutical Biotechnology, Nanjing University, Nanjing, 210008, China. .,Jiangsu Key Laboratory for Molecular Medicine, Medical School of Nanjing University, Nanjing, 210008, China.
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76
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Katsel P, Haroutunian V. Is Alzheimer disease a failure of mobilizing immune defense? Lessons from cognitively fit oldest-old. DIALOGUES IN CLINICAL NEUROSCIENCE 2019. [PMID: 31607776 PMCID: PMC6780355 DOI: 10.31887/dcns.2019.21.1/vharoutunian] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Multifaceted evidence supports the hypothesis that inflammatory-immune mechanisms contribute to Alzheimer disease (AD) neuropathology and genetic association of several immune specific genes (TREM2, CR1, and CD33) suggests that maladaptive immune responses may be pivotal drivers of AD pathogenesis. We reviewed microglia-related data from postmortem AD studies and examined supporting evidence from AD animal models to answer the following questions: i) What is the temporal sequence of immune activation in AD progression and what is its impact on cognition? ii) Are there discordant, “primed”, microglia responses in AD vs successful cognitive aging? iii) Does central nervous system (CNS) repair in aging depend on recruitment of the elements of cellular adaptive immune response such as effector T cells, and can the recruitment of systemic immune cells ameliorate AD neuropathology? iv) How effective are the immune-system-based therapeutic approaches currently employed for the treatment of AD?
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Affiliation(s)
- Pavel Katsel
- Department of Psychiatry, The Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Vahram Haroutunian
- Department of Neuroscience, The Icahn School of Medicine at Mount Sinai, New York, NY, USA; Mental Illness Research, Education and Clinical Center (MIRECC), James J. Peters VA Medical Center, Bronx, NY, USA
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77
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Microglial cell loss after ischemic stroke favors brain neutrophil accumulation. Acta Neuropathol 2019; 137:321-341. [PMID: 30580383 PMCID: PMC6513908 DOI: 10.1007/s00401-018-1954-4] [Citation(s) in RCA: 166] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 12/18/2018] [Accepted: 12/19/2018] [Indexed: 12/20/2022]
Abstract
Stroke attracts neutrophils to the injured brain tissue where they can damage the integrity of the blood-brain barrier and exacerbate the lesion. However, the mechanisms involved in neutrophil transmigration, location and accumulation in the ischemic brain are not fully elucidated. Neutrophils can reach the perivascular spaces of brain vessels after crossing the endothelial cell layer and endothelial basal lamina of post-capillary venules, or migrating from the leptomeninges following pial vessel extravasation and/or a suggested translocation from the skull bone marrow. Based on previous observations of microglia phagocytosing neutrophils recruited to the ischemic brain lesion, we hypothesized that microglial cells might control neutrophil accumulation in the injured brain. We studied a model of permanent occlusion of the middle cerebral artery in mice, including microglia- and neutrophil-reporter mice. Using various in vitro and in vivo strategies to impair microglial function or to eliminate microglia by targeting colony stimulating factor 1 receptor (CSF1R), this study demonstrates that microglial phagocytosis of neutrophils has fundamental consequences for the ischemic tissue. We found that reactive microglia engulf neutrophils at the periphery of the ischemic lesion, whereas local microglial cell loss and dystrophy occurring in the ischemic core are associated with the accumulation of neutrophils first in perivascular spaces and later in the parenchyma. Accordingly, microglia depletion by long-term treatment with a CSF1R inhibitor increased the numbers of neutrophils and enlarged the ischemic lesion. Hence, microglial phagocytic function sets a critical line of defense against the vascular and tissue damaging capacity of neutrophils in brain ischemia.
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78
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Yew WP, Djukic ND, Jayaseelan JSP, Walker FR, Roos KAA, Chataway TK, Muyderman H, Sims NR. Early treatment with minocycline following stroke in rats improves functional recovery and differentially modifies responses of peri-infarct microglia and astrocytes. J Neuroinflammation 2019; 16:6. [PMID: 30626393 PMCID: PMC6325745 DOI: 10.1186/s12974-018-1379-y] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2018] [Accepted: 11/26/2018] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND Altered neuronal connectivity in peri-infarct tissue is an important contributor to both the spontaneous recovery of neurological function that commonly develops after stroke and improvements in recovery that have been induced by experimental treatments in animal models. Microglia and astrocytes are primary determinants of the environment in peri-infarct tissue and hence strongly influence the potential for neuronal plasticity. However, the specific roles of these cells and the timing of critical changes in their function are not well understood. Minocycline can protect against ischemic damage and promote recovery. These effects are usually attributed, at least partially, to the ability of this drug to suppress microglial activation. This study tested the ability of minocycline treatment early after stroke to modify reactive responses in microglia and astrocytes and improve recovery. METHODS Stroke was induced by photothrombosis in the forelimb sensorimotor cortex of Sprague-Dawley rats. Minocycline was administered for 2 days after stroke induction and the effects on forelimb function assessed up to 28 days. The responses of peri-infarct Iba1-positive cells and astrocytes were evaluated using immunohistochemistry and Western blots. RESULTS Initial characterization showed that the numbers of Iba1-positive microglia and macrophages decreased in peri-infarct tissue at 24 h then increased markedly over the next few days. Morphological changes characteristic of activation were readily apparent by 3 h and increased by 24 h. Minocycline treatment improved the rate of recovery of motor function as measured by a forelimb placing test but did not alter infarct volume. At 3 days, there were only minor effects on core features of peri-infarct microglial reactivity including the morphological changes and increased density of Iba1-positive cells. The treatment caused a decrease of 57% in the small subpopulation of cells that expressed CD68, a marker of phagocytosis. At 7 days, the expression of glial fibrillary acidic protein and vimentin was markedly increased by minocycline treatment, indicating enhanced reactive astrogliosis. CONCLUSIONS Early post-stroke treatment with minocycline improved recovery but had little effect on key features of microglial activation. Both the decrease in CD68-positive cells and the increased activation of astrogliosis could influence neuronal plasticity and contribute to the improved recovery.
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Affiliation(s)
- Wai Ping Yew
- Centre for Neuroscience, College of Medicine and Public Health, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia
| | - Natalia D Djukic
- Centre for Neuroscience, College of Medicine and Public Health, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia
| | - Jaya S P Jayaseelan
- Centre for Neuroscience, College of Medicine and Public Health, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia
| | - Frederick R Walker
- Hunter Medical Research Institute; School of Biomedical Medical Sciences and Pharmacy, University of Newcastle Priority Research Centre in Stroke and Traumatic Brain Injury, Newcastle, NSW, Australia
| | - Karl A A Roos
- Hunter Medical Research Institute; School of Biomedical Medical Sciences and Pharmacy, University of Newcastle Priority Research Centre in Stroke and Traumatic Brain Injury, Newcastle, NSW, Australia
| | - Timothy K Chataway
- Centre for Neuroscience, College of Medicine and Public Health, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia
| | - Hakan Muyderman
- Centre for Neuroscience, College of Medicine and Public Health, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia
| | - Neil R Sims
- Centre for Neuroscience, College of Medicine and Public Health, Flinders University, GPO Box 2100, Adelaide, SA, 5001, Australia.
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Jin X, Riew TR, Kim HL, Kim S, Lee MY. Spatiotemporal Expression of GRP78 in the Blood Vessels of Rats Treated With 3-Nitropropionic Acid Correlates With Blood-Brain Barrier Disruption. Front Cell Neurosci 2018; 12:434. [PMID: 30515081 PMCID: PMC6255854 DOI: 10.3389/fncel.2018.00434] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 11/01/2018] [Indexed: 11/13/2022] Open
Abstract
Glucose-regulated protein (GRP78) or BiP, a 78-kDa chaperone protein located in the endoplasmic reticulum (ER), has recently been reported to be involved in the neuroglial response to ischemia-induced ER stress. The present study was designed to study the expression patterns of this protein and the cell types involved in the induction of GRP78 expression in rats treated with the mitochondrial toxin 3-nitropropionic acid (3-NP). GRP78 immunoreactivity was almost exclusively localized to striatal neurons in saline-treated controls, but GRP78 expression was induced in activated glial cells, including reactive astrocytes and activated microglia/macrophages, in the striata of rats treated with 3-NP. In the lesion core, increased GRP78 immunoreactivity was observed in the vasculature; this was evident in the lesion periphery of the core at 3 days after lesion induction, and was evenly distributed throughout the lesion core by 7 days after lesion induction. Vascular GRP78 expression was correlated, both temporally and spatially, with infiltration of activated microglia into the lesion core. In addition, this was coincident with the time and pattern of blood-brain barrier (BBB) leakage, detected by the extravasation of fluorescein isothiocyanate-albumin, an established BBB permeability marker. Vascular GRP78-positive cells in the lesion core were identified as endothelial cells, smooth muscle cells, and adventitial fibroblast-like cells, in which GRP78 protein was specifically localized to the cisternae of the rough ER and perinuclear cisternae, but not to other organelles such as mitochondria or nuclei. Thus, our data provide novel insights into the phenotypic and functional heterogeneity of GRP78-positive cells within the lesion core, suggesting the involvement of GRP78 in the activation/recruitment of activated microglia/macrophages and its potential role in BBB impairment in response to a 3-NP-mediated neurotoxic insult.
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Affiliation(s)
- Xuyan Jin
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul, South Korea.,Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Tae-Ryong Riew
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Hong Lim Kim
- Integrative Research Support Center, Laboratory of Electron Microscope, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Soojin Kim
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul, South Korea
| | - Mun-Yong Lee
- Department of Anatomy, Catholic Neuroscience Institute, College of Medicine, The Catholic University of Korea, Seoul, South Korea.,Department of Biomedicine and Health Sciences, College of Medicine, The Catholic University of Korea, Seoul, South Korea
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80
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Gaire BP, Song MR, Choi JW. Sphingosine 1-phosphate receptor subtype 3 (S1P 3) contributes to brain injury after transient focal cerebral ischemia via modulating microglial activation and their M1 polarization. J Neuroinflammation 2018; 15:284. [PMID: 30305119 PMCID: PMC6180378 DOI: 10.1186/s12974-018-1323-1] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Accepted: 09/24/2018] [Indexed: 12/16/2022] Open
Abstract
Background The pathogenic roles of receptor-mediated sphingosine 1-phosphate (S1P) signaling in cerebral ischemia have been evidenced mainly through the efficacy of FTY720 that binds non-selectively to four of the five S1P receptors (S1P1,3,4,5). Recently, S1P1 and S1P2 were identified as specific receptor subtypes that contribute to brain injury in cerebral ischemia; however, the possible involvement of other S1P receptors remains unknown. S1P3 can be the candidate because of its upregulation in the ischemic brain, which was addressed in this study, along with underlying pathogenic mechanisms. Methods We used transient middle cerebral artery occlusion/reperfusion (tMCAO), a mouse model of transient focal cerebral ischemia. To identify S1P3 as a pathogenic factor in cerebral ischemia, we employed a specific S1P3 antagonist, CAY10444. Brain damages were assessed by brain infarction, neurological score, and neurodegeneration. Histological assessment was carried out to determine microglial activation, morphological transformation, and proliferation. M1/M2 polarization and relevant signaling pathways were determined by biochemical and immunohistochemical analysis. Results Inhibiting S1P3 immediately after reperfusion with CAY10444 significantly reduced tMCAO-induced brain infarction, neurological deficit, and neurodegeneration. When S1P3 activity was inhibited, the number of activated microglia was markedly decreased in both the periischemic and ischemic core regions in the ischemic brain 1 and 3 days following tMCAO. Moreover, inhibiting S1P3 significantly restored the microglial shape from amoeboid to ramified microglia in the ischemic core region 3 days after tMCAO, and it attenuated microglial proliferation in the ischemic brain. In addition to these changes, S1P3 signaling influenced the proinflammatory M1 polarization, but not M2. The S1P3-dependent regulation of M1 polarization was clearly shown in activated microglia, which was affirmed by determining the in vivo activation of microglial NF-κB signaling that is responsible for M1 and in vitro expression levels of proinflammatory cytokines in activated microglia. As downstream effector pathways in an ischemic brain, S1P3 influenced phosphorylation of ERK1/2, p38 MAPK, and Akt. Conclusions This study identified S1P3 as a pathogenic mediator in an ischemic brain along with underlying mechanisms, involving its modulation of microglial activation and M1 polarization, further suggesting that S1P3 can be a therapeutic target for cerebral ischemia. Electronic supplementary material The online version of this article (10.1186/s12974-018-1323-1) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Bhakta Prasad Gaire
- College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon, 406-799, Republic of Korea
| | - Mi-Ryoung Song
- School of Life Sciences, Gwangju Institute of Science and Technology, Buk-gu, Gwangju, 500-712, Republic of Korea.
| | - Ji Woong Choi
- College of Pharmacy and Gachon Institute of Pharmaceutical Sciences, Gachon University, Incheon, 406-799, Republic of Korea.
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Jang Y, Woo KA, Lee ST, Park SH, Chu K, Lee SK. Cerebral autoinflammatory disease treated with anakinra. Ann Clin Transl Neurol 2018; 5:1428-1433. [PMID: 30480037 PMCID: PMC6243374 DOI: 10.1002/acn3.656] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2018] [Revised: 08/26/2018] [Accepted: 08/30/2018] [Indexed: 12/25/2022] Open
Abstract
Interest in autoimmune encephalitis has been growing since the discovery of various autoimmune antibodies, such as N‐methyl D‐aspartate receptors antibody and leucine‐rich glioma‐inactivated 1 antibody. However, in contrast to autoimmune encephalitis associated with dysregulated adaptive immunity in the brain, the question of whether innate immunity‐mediated autoinflammatory diseases exist in the brain has drawn much attention. Herein, we report a patient with microglia‐dominant acute autoinflammatory encephalitis successfully treated with anakinra, an including interleukin‐1 receptor blocker. In comparison to systemic autoinflammatory disease, we term this encephalitis cerebral autoinflammatory disease. Cerebral autoinflammatory disease could suggest new conceptual approaches to patients previously diagnosed with an unspecified encephalitis.
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Affiliation(s)
- Yoonhyuk Jang
- Department of Neurology Seoul National University Hospital Seoul South Korea
| | - Kyung Ah Woo
- Department of Neurology Seoul National University Hospital Seoul South Korea
| | - Soon-Tae Lee
- Department of Neurology Seoul National University Hospital Seoul South Korea
| | - Sung-Hye Park
- Department of Pathology Seoul National University Hospital Seoul South Korea
| | - Kon Chu
- Department of Neurology Seoul National University Hospital Seoul South Korea
| | - Sang Kun Lee
- Department of Neurology Seoul National University Hospital Seoul South Korea
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82
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Szepesi Z, Manouchehrian O, Bachiller S, Deierborg T. Bidirectional Microglia-Neuron Communication in Health and Disease. Front Cell Neurosci 2018; 12:323. [PMID: 30319362 PMCID: PMC6170615 DOI: 10.3389/fncel.2018.00323] [Citation(s) in RCA: 290] [Impact Index Per Article: 48.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Accepted: 09/06/2018] [Indexed: 12/12/2022] Open
Abstract
Microglia are ramified cells that exhibit highly motile processes, which continuously survey the brain parenchyma and react to any insult to the CNS homeostasis. Although microglia have long been recognized as a crucial player in generating and maintaining inflammatory responses in the CNS, now it has become clear, that their function are much more diverse, particularly in the healthy brain. The innate immune response and phagocytosis represent only a little segment of microglia functional repertoire that also includes maintenance of biochemical homeostasis, neuronal circuit maturation during development and experience-dependent remodeling of neuronal circuits in the adult brain. Being equipped by numerous receptors and cell surface molecules microglia can perform bidirectional interactions with other cell types in the CNS. There is accumulating evidence showing that neurons inform microglia about their status and thus are capable of controlling microglial activation and motility while microglia also modulate neuronal activities. This review addresses the topic: how microglia communicate with other cell types in the brain, including fractalkine signaling, secreted soluble factors and extracellular vesicles. We summarize the current state of knowledge of physiological role and function of microglia during brain development and in the mature brain and further highlight microglial contribution to brain pathologies such as Alzheimer’s and Parkinson’s disease, brain ischemia, traumatic brain injury, brain tumor as well as neuropsychiatric diseases (depression, bipolar disorder, and schizophrenia).
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Affiliation(s)
- Zsuzsanna Szepesi
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Oscar Manouchehrian
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Sara Bachiller
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Tomas Deierborg
- Experimental Neuroinflammation Laboratory, Department of Experimental Medical Science, Lund University, Lund, Sweden
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83
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Pivotal role of innate myeloid cells in cerebral post-ischemic sterile inflammation. Semin Immunopathol 2018; 40:523-538. [PMID: 30206661 DOI: 10.1007/s00281-018-0707-8] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Accepted: 09/04/2018] [Indexed: 12/17/2022]
Abstract
Inflammatory responses play a multifaceted role in regulating both disability and recovery after ischemic brain injury. In the acute phase of ischemic stroke, resident microglia elicit rapid inflammatory responses by the ischemic milieu. After disruption of the blood-brain barrier, peripheral-derived neutrophils and mononuclear phagocytes infiltrate into the ischemic brain. These infiltrating myeloid cells are activated by the endogenous alarming molecules released from dying brain cells. Inflammation after ischemic stroke thus typically consists of sterile inflammation triggered by innate immunity, which exacerbates the pathologies of ischemic stroke and worsens neurological prognosis. Infiltrating immune cells sustain the post-ischemic inflammation for several days; after this period, however, these cells take on a repairing function, phagocytosing inflammatory mediators and cellular debris. This time-specific polarization of immune cells in the ischemic brain is a potential novel therapeutic target. In this review, we summarize the current understanding of the phase-dependent role of innate myeloid cells in ischemic stroke and discuss the cellular and molecular mechanisms of their inflammatory or repairing polarization from a therapeutic perspective.
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84
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Li R, Liu W, Yin J, Chen Y, Guo S, Fan H, Li X, Zhang X, He X, Duan C. TSG-6 attenuates inflammation-induced brain injury via modulation of microglial polarization in SAH rats through the SOCS3/STAT3 pathway. J Neuroinflammation 2018; 15:231. [PMID: 30126439 PMCID: PMC6102893 DOI: 10.1186/s12974-018-1279-1] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 08/13/2018] [Indexed: 12/15/2022] Open
Abstract
BACKGROUND An acute and drastic inflammatory response characterized by the production of inflammatory mediators is followed by stroke, including SAH. Overactivation of microglia parallels an excessive inflammatory response and worsened brain damage. Previous studies indicate that TSG-6 has potent immunomodulatory and anti-inflammatory properties. This study aimed to evaluate the effects of TSG-6 in modulating immune reaction and microglial phenotype shift after experimental SAH. METHODS The SAH model was established by endovascular puncture method for Sprague-Dawley rats (weighing 280-320 g). Recombinant human protein and specific siRNAs for TSG-6 were exploited in vivo. Brain injury was assessed by neurologic scores, brain water content, and Fluoro-Jade C (FJC) staining. Microglia phenotypic status was evaluated and determined by Western immunoblotting, quantitative real-time polymerase chain reaction (qPCR) analyses, flow cytometry, and immunofluorescence labeling. RESULTS SAH induced significant inflammation, and M1-dominated microglia polarization increased expression of TSG-6 and neurological dysfunction in rats. rh-TSG-6 significantly ameliorated brain injury, decreased proinflammatory mediators, and skewed microglia towards a more anti-inflammatory property 24-h after SAH. While knockdown of TSG-6 further induced detrimental effects of microglia accompanied with more neurological deficits, the anti-inflammation effects of rh-TSG-6 were associated with microglia phenotypic shift by regulating the level of SOCS3/STAT3 axis. CONCLUSIONS TSG-6 exerted neuroprotection against SAH-induced EBI in rats, mediated in part by skewing the balance of microglial response towards a protective phenotype, thereby preventing excessive tissue damage and improving functional outcomes. Our findings revealed the role of TSG-6 in modulating microglial response partially involved in the SOCS3/STAT3 pathway and TSG-6 may be a promising therapeutic target for the treatment of brain injury following SAH.
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Affiliation(s)
- Ran Li
- Department of Neurosurgery, Zhujiang Hospital, The National Key Clinical Specialty, The Neurosurgery Institute of Guangdong Province, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Southern Medical University, Guangzhou, 510282, China
| | - Wenchao Liu
- Department of Neurosurgery, Zhujiang Hospital, The National Key Clinical Specialty, The Neurosurgery Institute of Guangdong Province, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Southern Medical University, Guangzhou, 510282, China
| | - Jian Yin
- Department of Neurosurgery, Zhujiang Hospital, The National Key Clinical Specialty, The Neurosurgery Institute of Guangdong Province, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Southern Medical University, Guangzhou, 510282, China
| | - Yunchang Chen
- Department of Neurosurgery, Zhujiang Hospital, The National Key Clinical Specialty, The Neurosurgery Institute of Guangdong Province, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Southern Medical University, Guangzhou, 510282, China
| | - Shenquan Guo
- Department of Neurosurgery, Zhujiang Hospital, The National Key Clinical Specialty, The Neurosurgery Institute of Guangdong Province, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Southern Medical University, Guangzhou, 510282, China
| | - Haiyan Fan
- Department of Neurosurgery, Zhujiang Hospital, The National Key Clinical Specialty, The Neurosurgery Institute of Guangdong Province, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Southern Medical University, Guangzhou, 510282, China
| | - Xifeng Li
- Department of Neurosurgery, Zhujiang Hospital, The National Key Clinical Specialty, The Neurosurgery Institute of Guangdong Province, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Southern Medical University, Guangzhou, 510282, China
| | - Xin Zhang
- Department of Neurosurgery, Zhujiang Hospital, The National Key Clinical Specialty, The Neurosurgery Institute of Guangdong Province, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Southern Medical University, Guangzhou, 510282, China
| | - Xuying He
- Department of Neurosurgery, Zhujiang Hospital, The National Key Clinical Specialty, The Neurosurgery Institute of Guangdong Province, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Southern Medical University, Guangzhou, 510282, China
| | - Chuanzhi Duan
- Department of Neurosurgery, Zhujiang Hospital, The National Key Clinical Specialty, The Neurosurgery Institute of Guangdong Province, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Southern Medical University, Guangzhou, 510282, China.
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85
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Hierro-Bujalance C, Bacskai BJ, Garcia-Alloza M. In Vivo Imaging of Microglia With Multiphoton Microscopy. Front Aging Neurosci 2018; 10:218. [PMID: 30072888 PMCID: PMC6060250 DOI: 10.3389/fnagi.2018.00218] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 06/26/2018] [Indexed: 01/04/2023] Open
Abstract
Neuroimaging has become an unparalleled tool to understand the central nervous system (CNS) anatomy, physiology and neurological diseases. While an altered immune function and microglia hyperactivation are common neuropathological features for many CNS disorders and neurodegenerative diseases, direct assessment of the role of microglial cells remains a challenging task. Non-invasive neuroimaging techniques, including magnetic resonance imaging (MRI), positron emission tomography (PET) and single positron emission computed tomography (SPECT) are widely used for human clinical applications, and a variety of ligands are available to detect neuroinflammation. In animal models, intravital imaging has been largely used, and minimally invasive multiphoton microcopy (MPM) provides high resolution detection of single microglia cells, longitudinally, in living brain. In this study, we review in vivo real-time MPM approaches to assess microglia in preclinical studies, including individual cell responses in surveillance, support, protection and restoration of brain tissue integrity, synapse formation, homeostasis, as well as in different pathological situations. We focus on in vivo studies that assess the role of microglia in mouse models of Alzheimer’s disease (AD), analyzing microglial motility and recruitment, as well as the role of microglia in anti-amyloid-β treatment, as a key therapeutic approach to treat AD. Altogether, MPM provides a high contrast and high spatial resolution approach to follow microglia chronically in vivo in complex models, supporting MPM as a powerful tool for deep intravital tissue imaging.
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Affiliation(s)
- Carmen Hierro-Bujalance
- Division of Physiology, School of Medicine, Instituto de Investigación e Innovación en Ciencias Biomedicas de la Provincia de Cadiz (INiBICA), Universidad de Cádiz, Cádiz, Spain
| | - Brian J Bacskai
- Alzheimer Research Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Harvard University, Boston, MA, United States
| | - Monica Garcia-Alloza
- Division of Physiology, School of Medicine, Instituto de Investigación e Innovación en Ciencias Biomedicas de la Provincia de Cadiz (INiBICA), Universidad de Cádiz, Cádiz, Spain
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86
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Fang W, Zhai X, Han D, Xiong X, Wang T, Zeng X, He S, Liu R, Miyata M, Xu B, Zhao H. CCR2-dependent monocytes/macrophages exacerbate acute brain injury but promote functional recovery after ischemic stroke in mice. Am J Cancer Res 2018; 8:3530-3543. [PMID: 30026864 PMCID: PMC6037034 DOI: 10.7150/thno.24475] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2017] [Accepted: 04/21/2018] [Indexed: 12/31/2022] Open
Abstract
Rationale: Peripheral blood monocytes are recruited into the ischemic brain and transform into macrophages after stroke. Nevertheless, the exact role of CCR2-dependent monocytes/macrophages in brain injury after stroke remains elusive. Methods: We used CCR2 knockout (KO) mice and the CCR2 pharmacological inhibitor, propagermanium (PG), to address the role of CCR2-dependent monocytes/macrophages in the acute stage and neurological functional recovery after middle cerebral artery (MCA) occlusion and reperfusion. Results: CCR2 KO resulted in smaller infarct size and lower mortality than in wild type (WT) mice, when measured 3 days after stroke. However, from 5 to 28 days after stroke, the KO mice had higher mortality and showed no obvious neurological functional recovery. In addition, WT mice treated with PG had similar stroke outcomes compared with CCR2 KO, as measured by T2 weighted MRI. Flow cytometry and real-time PCR analyses suggest that monocyte-derived macrophages (MoDMs) in the stroke brains mainly polarized to pro-inflammatory macrophages at the early stage, but gradually switched to anti-inflammatory macrophages at 7 days after stroke. In addition, adoptive transfer of anti-inflammatory macrophages into CCR2 KO mice at 4 and 6 days after stroke alleviated mortality and promoted neurological recovery. Conclusion: CCR2-dependent monocytes/macrophages are a double-edged sword; they worsen acute brain injury, but are essential for neurological recovery by promoting anti-inflammatory macrophage polarization.
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87
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Amantea D, Greco R, Micieli G, Bagetta G. Paradigm Shift to Neuroimmunomodulation for Translational Neuroprotection in Stroke. Front Neurosci 2018; 12:241. [PMID: 29692708 PMCID: PMC5903066 DOI: 10.3389/fnins.2018.00241] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Accepted: 03/27/2018] [Indexed: 12/11/2022] Open
Abstract
The treatment of acute ischemic stroke is still an unresolved clinical problem since the only approved therapeutic intervention relies on early blood flow restoration through pharmacological thrombolysis, mechanical thrombus removal, or a combination of both strategies. Due to their numerous complications and to the narrow time-window for the intervention, only a minority of stroke patients can actually benefit from revascularization procedures, highlighting the urgent need of identifying novel strategies to prevent the progression of an irreversible damage in the ischemic penumbra. During the past three decades, the attempts to target the pathways implicated in the ischemic cascade (e.g., excitotoxicity, calcium channels overactivation, reactive oxygen species (ROS) production) have failed in the clinical setting. Based on a better understanding of the pathobiological mechanisms and on a critical reappraisal of most failed trials, numerous findings from animal studies have demonstrated that targeting the immune system may represent a promising approach to achieve neuroprotection in stroke. In particular, given the dualistic role of distinct components of both the innate and adaptive arms of the immune system, a strategic intervention should be aimed at establishing the right equilibrium between inflammatory and reparative mechanisms, taking into consideration their spatio-temporal recruitment after the ischemic insult. Thus, the application of immunomodulatory drugs and their ability to ameliorate outcomes deserve validation in patients with acute ischemic stroke.
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Affiliation(s)
- Diana Amantea
- Section of Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Cosenza, Italy
| | - Rosaria Greco
- Laboratory of Neurophysiology of Integrative Autonomic Systems, Headache Science Centre, IRCCS Mondino Foundation, Pavia, Italy
| | - Giuseppe Micieli
- Department of Emergency Neurology, IRCCS Mondino Foundation, Pavia, Italy
| | - Giacinto Bagetta
- Section of Preclinical and Translational Pharmacology, Department of Pharmacy, Health and Nutritional Sciences, University of Calabria, Cosenza, Italy
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88
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Distinguishing features of microglia- and monocyte-derived macrophages after stroke. Acta Neuropathol 2018; 135:551-568. [PMID: 29249001 DOI: 10.1007/s00401-017-1795-6] [Citation(s) in RCA: 74] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 12/11/2017] [Accepted: 12/11/2017] [Indexed: 01/19/2023]
Abstract
After stroke, macrophages in the ischemic brain may be derived from either resident microglia or infiltrating monocytes. Using bone marrow (BM)-chimerism and dual-reporter transgenic fate mapping, we here set out to delimit the responses of either cell type to mild brain ischemia in a mouse model of 30 min transient middle cerebral artery occlusion (MCAo). A discriminatory analysis of gene expression at 7 days post-event yielded 472 transcripts predominantly or exclusively expressed in blood-derived macrophages as well as 970 transcripts for microglia. The differentially regulated genes were further collated with oligodendrocyte, astrocyte, and neuron transcriptomes, resulting in a dataset of microglia- and monocyte-specific genes in the ischemic brain. Functional categories significantly enriched in monocytes included migration, proliferation, and calcium signaling, indicative of strong activation. Whole-cell patch-clamp analysis further confirmed this highly activated state by demonstrating delayed outward K+ currents selectively in invading cells. Although both cell types displayed a mixture of known phenotypes pointing to the significance of 'intermediate states' in vivo, blood-derived macrophages were generally more skewed toward an M2 neuroprotective phenotype. Finally, we found that decreased engraftment of blood-borne cells in the ischemic brain of chimeras reconstituted with BM from Selplg-/- mice resulted in increased lesions at 7 days and worse post-stroke sensorimotor performance. In aggregate, our study establishes crucial differences in activation state between resident microglia and invading macrophages after stroke and identifies unique genomic signatures for either cell type.
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89
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Dual extra-retinal origins of microglia in the model of retinal microglia repopulation. Cell Discov 2018; 4:9. [PMID: 29507754 PMCID: PMC5827656 DOI: 10.1038/s41421-018-0011-8] [Citation(s) in RCA: 64] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 01/03/2018] [Indexed: 12/14/2022] Open
Abstract
Elucidating the origin of microglia is crucial for understanding their functions and homeostasis. Previous study has indicated that Nestin-positive progenitor cells differentiate into microglia and replenish the brain after depleting most brain microglia. Microglia have also shown the capacity to repopulate the retina after eliminating all retinal microglia. However, the origin(s) of repopulated retinal microglia is/are unknown. In this study, we aim to investigate the origins of repopulated microglia in the retina. Interestingly, we find that repopulated retinal microglia are not derived from Nestin-positive progenitor cells. Instead, they have two origins: the center-emerging microglia are derived from residual microglia in the optic nerve and the periphery-emerging microglia are derived from macrophages in the ciliary body/iris. Therefore, we have for the first time identified the extra-retinal origins of microglia in the adult mammalian retina by using a model of microglial repopulation, which may shed light on the target exploration of therapeutic interventions for retinal degenerative disorders.
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90
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Focal Ischaemic Infarcts Expand Faster in Cerebellar Cortex than Cerebral Cortex in a Mouse Photothrombotic Stroke Model. Transl Stroke Res 2018; 9:643-653. [PMID: 29455391 DOI: 10.1007/s12975-018-0615-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/02/2018] [Accepted: 02/04/2018] [Indexed: 12/31/2022]
Abstract
It is generally accepted that the cerebellum is particularly vulnerable to ischaemic injury, and this may contribute to the high mortality arising from posterior circulation strokes. However, this has not been systematically examined in an animal model. This study compared the development and resolution of matched photothrombotic microvascular infarcts in the cerebellar and cerebral cortices in adult 129/SvEv mice of both sexes. The photothrombotic lesions were made using tail vein injection of Rose Bengal with a 532 nm laser projected onto a 2 mm diameter aperture over the target region of the brain (with skull thinning). Infarct size was then imaged histologically following 2 h to 30-day survival using serial reconstruction of haematoxylin and eosin stained cryosections. This was complemented with immunohistochemistry for neuron and glial markers. At 2 h post-injury, the cerebellar infarct volume averaged ~ 2.7 times that of the cerebral cortex infarcts. Infarct volume reached maximum in the cerebellum in a quarter of the time (24 h) taken in the cerebral cortex (4 days). Remodelling resolved the infarcts within a month, leaving significantly larger residual injury volume in the cerebellum. The death of neurons in the core lesion at 2 h was confirmed by NeuN and Calbindin immunofluorescence, alongside activation of astrocytes and microglia. The latter persisted in the region within and surrounding the residual infarct at 30 days. This comparison of acute focal ischaemic injuries in cerebellar and cerebral cortices provides direct confirmation of exacerbation of neuropathology and faster kinetics in the cerebellum.
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91
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Boddaert J, Bielen K, ’s Jongers B, Manocha E, Yperzeele L, Cras P, Pirici D, Kumar-Singh S. CD8 signaling in microglia/macrophage M1 polarization in a rat model of cerebral ischemia. PLoS One 2018; 13:e0186937. [PMID: 29342151 PMCID: PMC5771556 DOI: 10.1371/journal.pone.0186937] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2017] [Accepted: 10/10/2017] [Indexed: 12/16/2022] Open
Abstract
Classical or M1 activity of microglia/macrophages has been described in several neurodegenerative and brain inflammatory conditions and has also been linked to expansion of ischemic injury in post-stroke brain. While different pathways of M1 polarization have been suggested to occur in the post-stroke brain, the precise underlying mechanisms remain undefined. Using a transient middle cerebral artery occlusion (MCAO) rat model, we showed a progressive M2 to M1 polarization in the perilesional brain region with M1 cells becoming one of the dominant subsets by day 4 post-stroke. Comparing key receptors involved in M1 polarization (CD8, IFNγR, Clec4, FcγR, TLR3 and TLR4) and their signal transducers (Syk, Stat1, Irf3, and Traf6) at the day 4 time point, we showed a strong upregulation of CD8 along with SYK transducer in dissected perilesional brain tissue. We further showed that CD8 expression in the post-stroke brain was associated with activated (CD68+) macrophages and that progressive accumulation of CD8+CD68+ cells in the post-stroke brain coincided with increased iNOS (M1 marker) and reduced Arg1 (M2 marker) expression on these cells. In vitro ligand-based stimulation of the CD8 receptor caused increased iNOS expression and an enhanced capacity to phagocytose E. coli particles; and interestingly, CD8 stimulation was also able to repolarize IL4-treated M2 cells to an M1 phenotype. Our data suggest that increased CD8 signaling in the post-stroke brain is primarily associated with microglia/macrophages and can independently drive M1 polarization, and that modulation of CD8 signaling could be a potential target to limit secondary post-stroke brain damage.
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Affiliation(s)
- Jan Boddaert
- Molecular Pathology Group, Cell Biology and Histology, Faculty of Medicine and Health Sciences, Wilrijk, Belgium
| | - Kenny Bielen
- Molecular Pathology Group, Cell Biology and Histology, Faculty of Medicine and Health Sciences, Wilrijk, Belgium
| | - Bart ’s Jongers
- Molecular Pathology Group, Cell Biology and Histology, Faculty of Medicine and Health Sciences, Wilrijk, Belgium
| | - Ekta Manocha
- Molecular Pathology Group, Cell Biology and Histology, Faculty of Medicine and Health Sciences, Wilrijk, Belgium
| | - Laetitia Yperzeele
- Department of Neurology, Universitair Ziekenhuis Antwerpen, Edegem, Belgium
| | - Patrick Cras
- Department of Neurology, Universitair Ziekenhuis Antwerpen, Edegem, Belgium
- Translational Neuroscience – Faculty of Medicine and Health Sciences, Wilrijk, Belgium
| | - Daniel Pirici
- Department of Research Methodology, University of Medicine and Pharmacy of Craiova, Craiova, Romania
| | - Samir Kumar-Singh
- Molecular Pathology Group, Cell Biology and Histology, Faculty of Medicine and Health Sciences, Wilrijk, Belgium
- Translational Neuroscience – Faculty of Medicine and Health Sciences, Wilrijk, Belgium
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92
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Abstract
Alzheimer's disease (AD) is the primary cause of age-related dementia. Effective strategies to prevent and treat AD remain elusive despite major efforts to understand its basic biology and clinical pathophysiology. Significant investments in therapeutic drug discovery programs over the past two decades have yielded some important insights but no blockbuster drugs to alter the course of disease. Because significant memory loss and cognitive decline are associated with neuron death and loss of gray matter, especially in the frontal cortex and hippocampus, some focus in drug development has shifted to early prevention of cellular pathology. Although clinical trial design is challenging, due in part to a lack of robust biomarkers with predictive value, some optimism has come from the identification and study of inherited forms of early-onset AD and genetic risk factors that provide insights about molecular pathophysiology and potential drug targets. In addition, better understanding of the Aβ amyloid pathway and the tau pathway-leading to amyloid plaques and neurofibrillary tangles, respectively, which are histopathological hallmarks of AD-continues to drive significant drug research and development programs. The main focus of this review is to summarize the most recent basic biology, biochemistry, and pharmacology that serve as a foundation for more than 50 active advanced-phase clinical trials for AD prevention and therapy.
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Affiliation(s)
- W Vallen Graham
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, NY 10065;
| | - Alessandra Bonito-Oliva
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, NY 10065;
| | - Thomas P Sakmar
- Laboratory of Chemical Biology and Signal Transduction, The Rockefeller University, New York, NY 10065; .,Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division of Neurogeriatrics, Karolinska Institutet, 141 57 Huddinge, Sweden
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93
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Begolly S, Olschowka JA, Love T, Williams JP, O'Banion MK. Fractionation enhances acute oligodendrocyte progenitor cell radiation sensitivity and leads to long term depletion. Glia 2017; 66:846-861. [PMID: 29288597 DOI: 10.1002/glia.23288] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2016] [Revised: 12/13/2017] [Accepted: 12/13/2017] [Indexed: 12/18/2022]
Abstract
Ionizing radiation (IR) is commonly used to treat central nervous system (CNS) cancers and metastases. While IR promotes remission, frequent side effects including impaired cognition and white matter loss occur following treatment. Fractionation is used to minimize these CNS late side effects, as it reduces IR effects in differentiated normal tissue, but not rapidly proliferating normal or tumor tissue. However, side effects occur even with the use of fractionated paradigms. Oligodendrocyte progenitor cells (OPCs) are a proliferative population within the CNS affected by radiation. We hypothesized that fractionated radiation would lead to OPC loss, which could contribute to the delayed white matter loss seen after radiation exposure. We found that fractionated IR induced a greater early loss of OPCs than an equivalent single dose exposure. Furthermore, OPC recovery was impaired following fractionated IR. Finally, reduced OPC differentiation and mature oligodendrocyte numbers occurred in single dose and fractionated IR paradigms. This work demonstrates that fractionation does not spare normal brain tissue and, importantly, highlights the sensitivity of OPCs to fractionated IR, suggesting that fractionated schedules may promote white matter dysfunction, a point that should be considered in radiotherapy.
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Affiliation(s)
- Sage Begolly
- Departments of Environmental Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York
| | - John A Olschowka
- Department of Neuroscience and Del Monte Neuroscience Institute, University of Rochester School of Medicine & Dentistry, Rochester, New York
| | - Tanzy Love
- Department of Biostatistics and Computational Biology, University of Rochester School of Medicine & Dentistry, Rochester, New York
| | - Jacqueline P Williams
- Departments of Environmental Medicine, University of Rochester School of Medicine & Dentistry, Rochester, New York.,Department of Radiation Oncology, University of Rochester School of Medicine & Dentistry, Rochester, New York
| | - M Kerry O'Banion
- Department of Neuroscience and Del Monte Neuroscience Institute, University of Rochester School of Medicine & Dentistry, Rochester, New York.,Department of Neurology, University of Rochester School of Medicine & Dentistry, Rochester, New York
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94
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Cruz SA, Hari A, Qin Z, Couture P, Huang H, Lagace DC, Stewart AFR, Chen HH. Loss of IRF2BP2 in Microglia Increases Inflammation and Functional Deficits after Focal Ischemic Brain Injury. Front Cell Neurosci 2017; 11:201. [PMID: 28769762 PMCID: PMC5515910 DOI: 10.3389/fncel.2017.00201] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 06/27/2017] [Indexed: 12/17/2022] Open
Abstract
Ischemic stroke causes neuronal cell death and triggers a cascade of inflammatory signals that contribute to secondary brain damage. Microglia, the brain-resident macrophages that remove dead neurons, play a critical role in the brain’s response to ischemic injury. Our previous studies showed that IRF2 binding protein 2 (IRF2BP2) regulates peripheral macrophage polarization, limits their inflammatory response and reduces susceptibility to atherosclerosis. Here, we show that loss of IRF2BP2 in microglia leads to increased inflammatory cytokine expression in response to lipopolysaccharide challenge and impaired activation of anti-inflammatory markers in response to interleukin-4 (IL4) stimulation. Focal ischemic brain injury of the sensorimotor cortex induced by photothrombosis caused more severe functional deficits in mice with IRF2BP2 ablated in macrophages/microglia, associated with elevated expression of inflammatory cytokines in the brain. These mutant mice had larger infarctions 4 days after stroke associated with fewer anti-inflammatory M2 microglia/macrophages recruited to the peri-infarct area, suggesting an impaired clearance of injured tissues. Since IRF2BP2 modulates interferon signaling, and interferon beta (IFNβ) has been reported to be anti-inflammatory and reduce ischemic brain injury, we asked whether loss of IRF2BP2 in macrophages/microglia would affect the response to IFNβ in our stroke model. IFNβ suppressed inflammatory cytokine production of macrophages and reduced infarct volumes at 4 days after photothrombosis in wild type mice. The anti-inflammatory effect of IFNβ was lost in IRF2BP2-deficient macrophages and IFNβ failed to protect mice lacking IRF2BP2 in macrophages/microglia from ischemic injury. In summary, IRF2BP2 expression in macrophages/microglia is important to limit inflammation and stroke injury, in part by mediating the beneficial effect of IFNβ.
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Affiliation(s)
- Shelly A Cruz
- Ottawa Hospital Research InstituteOttawa, ON, Canada.,Brain and Mind Institute, University of OttawaOttawa, ON, Canada.,Canadian Partnership for Stroke RecoveryOttawa, ON, Canada
| | - Aswin Hari
- Ottawa Hospital Research InstituteOttawa, ON, Canada.,Brain and Mind Institute, University of OttawaOttawa, ON, Canada.,Canadian Partnership for Stroke RecoveryOttawa, ON, Canada
| | - Zhaohong Qin
- Ottawa Hospital Research InstituteOttawa, ON, Canada.,Brain and Mind Institute, University of OttawaOttawa, ON, Canada
| | - Pascal Couture
- Ottawa Hospital Research InstituteOttawa, ON, Canada.,Brain and Mind Institute, University of OttawaOttawa, ON, Canada.,Cellular and Molecular Medicine, University of OttawaOttawa, ON, Canada
| | - Hua Huang
- Ottawa Hospital Research InstituteOttawa, ON, Canada.,Brain and Mind Institute, University of OttawaOttawa, ON, Canada.,University of Ottawa Heart InstituteOttawa, ON, Canada
| | - Diane C Lagace
- Brain and Mind Institute, University of OttawaOttawa, ON, Canada.,Canadian Partnership for Stroke RecoveryOttawa, ON, Canada.,Cellular and Molecular Medicine, University of OttawaOttawa, ON, Canada
| | - Alexandre F R Stewart
- University of Ottawa Heart InstituteOttawa, ON, Canada.,Biochemistry, Microbiology and Immunology, University of OttawaOttawa, ON, Canada
| | - Hsiao-Huei Chen
- Ottawa Hospital Research InstituteOttawa, ON, Canada.,Brain and Mind Institute, University of OttawaOttawa, ON, Canada.,Canadian Partnership for Stroke RecoveryOttawa, ON, Canada.,Cellular and Molecular Medicine, University of OttawaOttawa, ON, Canada.,Medicine, University of OttawaOttawa, ON, Canada
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95
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Spittau B. Aging Microglia-Phenotypes, Functions and Implications for Age-Related Neurodegenerative Diseases. Front Aging Neurosci 2017; 9:194. [PMID: 28659790 PMCID: PMC5469878 DOI: 10.3389/fnagi.2017.00194] [Citation(s) in RCA: 160] [Impact Index Per Article: 22.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 05/30/2017] [Indexed: 12/23/2022] Open
Abstract
Aging of the central nervous system (CNS) is one of the major risk factors for the development of neurodegenerative pathologies such as Parkinson’s disease (PD) and Alzheimer’s disease (AD). The molecular mechanisms underlying the onset of AD and especially PD are not well understood. However, neuroinflammatory responses mediated by microglia as the resident immune cells of the CNS have been reported for both diseases. The unique nature and developmental origin of microglia causing microglial self-renewal and telomere shortening led to the hypothesis that these CNS-specific innate immune cells become senescent. Age-dependent and senescence-driven impairments of microglia functions and responses have been suggested to play essential roles during onset and progression of neurodegenerative diseases. This review article summarizes the current knowledge of microglia phenotypes and functions in the aging CNS and further discusses the implications of these age-dependent microglia changes for the development and progression of AD and PD as the most common neurodegenerative diseases.
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Affiliation(s)
- Björn Spittau
- Department of Molecular Embryology, Faculty of Medicine, Institute for Anatomy and Cell Biology, University of FreiburgFreiburg, Germany.,Institute of Anatomy, University of RostockRostock, Germany
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96
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Kabba JA, Xu Y, Christian H, Ruan W, Chenai K, Xiang Y, Zhang L, Saavedra JM, Pang T. Microglia: Housekeeper of the Central Nervous System. Cell Mol Neurobiol 2017; 38:53-71. [PMID: 28534246 DOI: 10.1007/s10571-017-0504-2] [Citation(s) in RCA: 152] [Impact Index Per Article: 21.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/16/2017] [Indexed: 12/17/2022]
Abstract
Microglia, of myeloid origin, play fundamental roles in the control of immune responses and the maintenance of central nervous system homeostasis. These cells, just like peripheral macrophages, may be activated into M1 pro-inflammatory or M2 anti-inflammatory phenotypes by appropriate stimuli. Microglia do not respond in isolation, but form part of complex networks of cells influencing each other. This review addresses the complex interaction of microglia with each cell type in the brain: neurons, astrocytes, cerebrovascular endothelial cells, and oligodendrocytes. We also highlight the participation of microglia in the maintenance of homeostasis in the brain, and their roles in the development and progression of age-related neurodegenerative disorders.
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Affiliation(s)
- John Alimamy Kabba
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China
| | - Yazhou Xu
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China
| | - Handson Christian
- Department of Pharmacology, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, People's Republic of China
| | - Wenchen Ruan
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China
| | - Kitchen Chenai
- School of Pharmacy, China Pharmaceutical University, Nanjing, 210009, People's Republic of China
| | - Yun Xiang
- Department of Laboratory Medicine, Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science & Technology, Wuhan, 430016, People's Republic of China
| | - Luyong Zhang
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China
| | - Juan M Saavedra
- Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington DC, 20057, USA
| | - Tao Pang
- State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Drug Screening, Jiangsu Key Laboratory of Drug Discovery for Metabolic Diseases, Jiangsu Key Laboratory of Druggability of Biopharmaceuticals, China Pharmaceutical University, #24 Tong Jia Xiang Street, Nanjing, 210009, People's Republic of China. .,Department of Pharmacology and Physiology, Georgetown University Medical Center, Washington DC, 20057, USA.
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97
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Transcriptomic analysis reveals differential activation of microglial genes after ischemic stroke in mice. Neuroscience 2017; 348:212-227. [DOI: 10.1016/j.neuroscience.2017.02.019] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2016] [Revised: 01/26/2017] [Accepted: 02/10/2017] [Indexed: 02/08/2023]
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98
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Abstract
Cardiovascular diseases are a consequence of genetic and environmental risk factors that together generate arterial wall and cardiac pathologies. Blood vessels connect multiple systems throughout the entire body and allow organs to interact via circulating messengers. These same interactions facilitate nervous and metabolic system's influence on cardiovascular health. Multiparametric imaging offers the opportunity to study these interfacing systems' distinct processes, to quantify their interactions, and to explore how these contribute to cardiovascular disease. Noninvasive multiparametric imaging techniques are emerging tools that can further our understanding of this complex and dynamic interplay. Positron emission tomography/magnetic resonance imaging and multichannel optical imaging are particularly promising because they can simultaneously sample multiple biomarkers. Preclinical multiparametric diagnostics could help discover clinically relevant biomarker combinations pivotal for understanding cardiovascular disease. Interfacing systems important to cardiovascular disease include the immune, nervous, and hematopoietic systems. These systems connect with classical cardiovascular organs, such as the heart and vasculature, and with the brain. The dynamic interplay between these systems and organs enables processes, such as hemostasis, inflammation, angiogenesis, matrix remodeling, metabolism, and fibrosis. As the opportunities provided by imaging expand, mapping interconnected systems will help us decipher the complexity of cardiovascular disease and monitor novel therapeutic strategies.
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Affiliation(s)
- Katrien Vandoorne
- From the Center for Systems Biology (K.V., M.N.) and Department of Imaging (K.V., M.N.), Massachusetts General Hospital and Harvard Medical School, Boston; and Cardiovascular Research Center, Massachusetts General Hospital and Harvard Medical School, Boston (M.N.)
| | - Matthias Nahrendorf
- From the Center for Systems Biology (K.V., M.N.) and Department of Imaging (K.V., M.N.), Massachusetts General Hospital and Harvard Medical School, Boston; and Cardiovascular Research Center, Massachusetts General Hospital and Harvard Medical School, Boston (M.N.).
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99
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Gaire BP, Lee CH, Sapkota A, Lee SY, Chun J, Cho HJ, Nam TG, Choi JW. Identification of Sphingosine 1-Phosphate Receptor Subtype 1 (S1P 1) as a Pathogenic Factor in Transient Focal Cerebral Ischemia. Mol Neurobiol 2017; 55:2320-2332. [PMID: 28343295 DOI: 10.1007/s12035-017-0468-8] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2016] [Accepted: 02/23/2017] [Indexed: 01/06/2023]
Abstract
Medically relevant roles of receptor-mediated sphingosine 1-phosphate (S1P) signaling have become a successful or promising target for multiple sclerosis or cerebral ischemia. Animal-based proof-of-concept validation for the latter is particularly through the neuroprotective efficacy of FTY720, a non-selective S1P receptor modulator, presumably via activation of S1P1. In spite of a clear link between S1P signaling and cerebral ischemia, it remains unknown whether the role of S1P1 is pathogenic or neuroprotective. Here, we investigated the involvement of S1P1 along with its role in cerebral ischemia using a transient middle cerebral artery occlusion ("tMCAO") model. Brain damage following tMCAO, as assessed by brain infarction, neurological deficit score, and neural cell death, was reduced by oral administration of AUY954, a selective S1P1 modulator as a functional antagonist, in a therapeutic paradigm, indicating that S1P1 is a pathogenic mediator rather than a neuroprotective mediator. This pathogenic role of S1P1 in cerebral ischemia was reaffirmed because tMCAO-induced brain damage was reduced by genetic knockdown with an intracerebroventricular microinjection of S1P1 shRNA lentivirus into the brain. Genetic knockdown of S1P1 or AUY954 exposure reduced microglial activation, as assessed by reduction in the number of activated microglia and reversed morphology from amoeboid to ramified, and microglial proliferation in ischemic brain. Its role in microglial activation was recapitulated in lipopolysaccharide-stimulated primary mouse microglia, in which the mRNA expression level of TNF-α and IL-1β, well-known markers for microglial activation, was reduced in microglia transfected with S1P1 siRNA. These data suggest that the pathogenic role of S1P1 is associated with microglial activation in ischemic brain. Additionally, the pathogenic role of S1P1 in cerebral ischemia appears to be associated with the blood-brain barrier disruption and brain-derived neurotrophic factor (BDNF) downregulation. Overall, findings from the current study clearly identify S1P1 signaling as a pathogenic factor in transient focal cerebral ischemia, further implicating S1P1 antagonists including functional antagonists as plausible therapeutic agents for human stroke.
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Affiliation(s)
| | - Chi-Ho Lee
- Gachon University, Incheon, 406-799, Republic of Korea
| | - Arjun Sapkota
- Gachon University, Incheon, 406-799, Republic of Korea
| | - Sang Yeul Lee
- Department of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, 55 Hanynagdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do, 15588, Republic of Korea
| | - Jerold Chun
- Department of Molecular Biology, Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | - Hee Jun Cho
- TherlifEx, Namdong-gu, Incheon, 21653, Republic of Korea
| | - Tae-Gyu Nam
- Department of Pharmacy and Institute of Pharmaceutical Science and Technology, Hanyang University, Ansan, 55 Hanynagdaehak-ro, Sangnok-gu, Ansan, Gyeonggi-do, 15588, Republic of Korea.
| | - Ji Woong Choi
- Gachon University, Incheon, 406-799, Republic of Korea.
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100
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Marins FR, Iddings JA, Fontes MAP, Filosa JA. Evidence that remodeling of insular cortex neurovascular unit contributes to hypertension-related sympathoexcitation. Physiol Rep 2017; 5:e13156. [PMID: 28270592 PMCID: PMC5350170 DOI: 10.14814/phy2.13156] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 01/18/2017] [Indexed: 11/24/2022] Open
Abstract
The intermediate region of the posterior insular cortex (intermediate IC) mediates sympathoexcitatory responses to the heart and kidneys. Previous studies support hypertension-evoked changes to the structure and function of neurons, blood vessels, astrocytes and microglia, disrupting the organization of the neurovascular unit (NVU). In this study, we evaluated the functional and anatomical integrity of the NVU at the intermediate IC in the spontaneously hypertensive rat (SHR) and its control the Wistar-Kyoto (WKY). Under urethane anesthesia, NMDA microinjection (0.2 mmol/L/100 nL) was performed at the intermediate IC with simultaneous recording of renal sympathetic nerve activity (RSNA), heart rate (HR) and mean arterial pressure (MAP). Alterations in NVU structure were investigated by immunofluorescence for NMDA receptors (NR1), blood vessels (70 kDa FITC-dextran), astrocytes (GFAP), and microglia (Iba1). Injections of NMDA into intermediate IC of SHR evoked higher amplitude responses of RSNA, MAP, and HR On the other hand, NMDA receptor blockade decreased baseline RSNA, MAP and HR in SHR, with no changes in WKY Immunofluorescence data from SHR intermediate IC showed increased NMDA receptor density, contributing to the SHR enhanced sympathetic responses, and increased in vascular density (increased number of branches and endpoints, reduced average branch length), suggesting angiogenesis. Additionally, IC from SHR presented increased GFAP immunoreactivity and contact between astrocyte processes and blood vessels. In SHR, IC microglia skeleton analysis supports their activation (reduced number of branches, junctions, endpoints and process length), suggesting an inflammatory process in this region. These findings indicate that neurogenic hypertension in SHR is accompanied by marked alterations to the NVU within the IC and enhanced NMDA-mediated sympathoexcitatory responses likely contributors of the maintenance of hypertension.
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Affiliation(s)
- Fernanda R Marins
- Departamento de Fisiologia e Biofísica, INCT, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | | | - Marco A P Fontes
- Departamento de Fisiologia e Biofísica, INCT, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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