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Pesti I, Légrádi Á, Farkas E. Primary microglia cell cultures in translational research: Strengths and limitations. J Biotechnol 2024; 386:10-18. [PMID: 38519034 DOI: 10.1016/j.jbiotec.2024.03.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2024] [Revised: 03/13/2024] [Accepted: 03/13/2024] [Indexed: 03/24/2024]
Abstract
Microglia are the resident macrophages in the central nervous system, accounting for 10-15% of the cell mass in the brain. Next to their physiological role in development, monitoring neuronal function and the maintenance of homeostasis, microglia are crucial in the brain's immune defense. Brain injury and chronic neurological disorders are associated with neuroinflammation, in which microglia activation is a central element. Microglia acquire a wide spectrum of activation states in the diseased or injured brain, some of which are neurotoxic. The investigation of microglia (patho)physiology and therapeutic interventions targeting neuroinflammation is a substantial challenge. In addition to in vivo approaches, the application of in vitro model systems has gained significant ground and is essential to complement in vivo work. Primary microglia cultures have proved to be a useful tool. Microglia cultures have offered the opportunity to explore the mechanistic, molecular elements of microglia activation, the microglia secretome, and the efficacy of therapeutic treatments against neuroinflammation. As all model systems, primary microglia cultures have distinct strengths and limitations to be weighed when experiments are designed and when data are interpreted. Here, we set out to provide a succinct overview of the advantages and pitfalls of the use of microglia cultures, which instructs the refinement and further development of this technique to remain useful in the toolbox of microglia researchers. Since there is no conclusive therapy to combat neurotoxicity linked to neuroinflammation in acute brain injury or neurodegenerative disorders, these research tools remain essential to explore therapeutic opportunities.
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Affiliation(s)
- István Pesti
- Hungarian Centre of Excellence for Molecular Medicine - University of Szeged Cerebral Blood Flow and Metabolism Research Group, Somogyi u 4, Szeged 6720, Hungary; Department of Cell Biology and Molecular Medicine, Albert Szent-Györgyi Medical School and Faculty of Science and Informatics, University of Szeged, Somogyi u 4, Szeged 6720, Hungary
| | - Ádám Légrádi
- Department of Cell Biology and Molecular Medicine, Albert Szent-Györgyi Medical School and Faculty of Science and Informatics, University of Szeged, Somogyi u 4, Szeged 6720, Hungary
| | - Eszter Farkas
- Hungarian Centre of Excellence for Molecular Medicine - University of Szeged Cerebral Blood Flow and Metabolism Research Group, Somogyi u 4, Szeged 6720, Hungary; Department of Cell Biology and Molecular Medicine, Albert Szent-Györgyi Medical School and Faculty of Science and Informatics, University of Szeged, Somogyi u 4, Szeged 6720, Hungary.
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Akhmetzyanova ER, Rizvanov AA, Mukhamedshina YO. Current methods for the microglia isolation: Overview and comparative analysis of approaches. Cell Tissue Res 2024; 395:147-158. [PMID: 38099956 DOI: 10.1007/s00441-023-03853-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2023] [Accepted: 12/01/2023] [Indexed: 02/03/2024]
Abstract
Microglia represent a distinct population of neuroglia, constituting ~ 10% of all CNS cells and exhibit high plasticity. Proper functioning of microglia is critical in the event of CNS damage due to the rapid modulation of their functions. Microglia are not only the first stage of immune defense against injury and infection, contributing to both the innate and adaptive local immune response, but also play a vital role in maintaining homeostasis of the brain and spinal cord. For this reason, microglia deserve special attention in the study of neuropathological responses. Studying microglia behavior in various in vivo models of neuropathologies is certainly a priority, as it allows us to evaluate the behavior in the context of the changing microenvironment of nervous tissue. However, sometimes there are some technological problems that hinder the identification of the features of intercellular interactions, ensured cooperation between microglia and other cell types. In this regard, the use of in vitro models remains relevant today, contributing to a more in-depth understanding of the mechanisms of microglial involvement in neuropathology. The methods considered in this review for obtaining an isolated culture of microglia, along with their advantages and disadvantages, can help researchers in selecting the appropriate source and method for obtaining these cells, thereby opening up opportunities for gaining new neurobiological knowledge.
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Affiliation(s)
- E R Akhmetzyanova
- OpenLab Gene and Cell Technology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420008, Kazan, Russia.
| | - A A Rizvanov
- OpenLab Gene and Cell Technology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420008, Kazan, Russia
| | - Y O Mukhamedshina
- OpenLab Gene and Cell Technology, Institute of Fundamental Medicine and Biology, Kazan Federal University, 420008, Kazan, Russia
- Department of Histology, Cytology, and Embryology, Kazan State Medical University, 420012, Kazan, Russia
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Ray SK. TUNEL-n-DIFL Method for Detection and Estimation of Apoptosis Specifically in Neurons and Glial Cells in Mixed Culture and Animal Models of Central Nervous System Diseases and Injuries. Methods Mol Biol 2024; 2761:1-26. [PMID: 38427225 DOI: 10.1007/978-1-0716-3662-6_1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2024]
Abstract
Detection of merely apoptosis does not reveal the type of central nervous system (CNS) cells that are dying in the CNS diseases and injuries. In situ detection and estimation of amount of apoptosis specifically in neurons or glial cells (astrocytes, oligodendrocytes, and microglia) can unveil valuable information for designing therapeutics for protection of the CNS cells and functional recovery. A method was first developed and reported from our laboratory for in situ detection and estimation of amount of apoptosis precisely in neurons and glial cells using in vitro and in vivo models of CNS diseases and injuries. This is a combination of terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and double immunofluorescent labeling (DIFL) or simply TUNEL-n-DIFL method for in situ detection and estimation of amount of apoptosis in a specific CNS cell type. An anti-digoxigenin (DIG) IgG antibody conjugated with 7-amino-4-methylcoumarin-3-acetic acid (AMCA) for blue fluorescence, fluorescein isothiocyanate (FITC) for green fluorescence, or Texas Red (TR) for red fluorescence can be used for in situ detection of apoptotic cell DNA, which is earlier labeled with TUNEL using alkali-stable DIG-11-dUTP. A primary anti-NeuN (neurons), anti-GFAP (astrocytes), anti-MBP (oligodendrocytes), or anti-OX-42 (microglia) IgG antibody and a secondary IgG antibody conjugated with one of the above fluorophores (other than that of ani-DIG antibody) are used for in situ detection of apoptosis in a specific CNS cell type in the mixed culture and animal models of the CNS diseases and injuries.
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Affiliation(s)
- Swapan K Ray
- Department of Pathology, Microbiology, and Immunology, University of South Carolina School of Medicine, Columbia, SC, USA.
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Zelenka L, Jarek M, Pägelow D, Geffers R, van Vorst K, Fulde M. Crosstalk of Highly Purified Microglia and Astrocytes in the Frame of Toll-like Receptor (TLR)2/1 Activation. Neuroscience 2023; 526:256-266. [PMID: 37391121 DOI: 10.1016/j.neuroscience.2023.05.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 04/26/2023] [Accepted: 05/02/2023] [Indexed: 07/02/2023]
Abstract
The major immune cells of the central nervous systems (CNS) are microglia and astrocytes, subsets of the glial cell population. The crosstalk between glia via soluble signaling molecules plays an indispensable role for neuropathologies, brain development as well as homeostasis. However, the investigation of the microglia-astrocyte crosstalk has been hampered due to the lack of suitable glial isolation methods. In this study, we investigated for the first time the crosstalk between highly purified Toll-like receptor (TLR)2-knock out (TLR2-KO) and wild-type (WT) microglia and astrocytes. We examined the crosstalk of TLR2-KO microglia and astrocytes in the presence of WT supernatants of the respective other glial cell type. Interestingly, we observed a significant TNF release by TLR2-KO astrocytes, which were activated with Pam3CSK4-stimulated WT microglial supernatants, strongly indicating a crosstalk between microglia and astrocytes after TLR2/1 activation. Furthermore, transcriptome analysis using RNA-seq revealed a wide range of significant up- and down-regulated genes such as Cd300, Tnfrsf9 or Lcn2, which might be involved in the molecular conversation between microglia and astrocytes. Finally, co-culturing microglia and astrocytes confirmed the prior results by demonstrating a significant TNF release by WT microglia co-cultured with TLR2-KO astrocytes. Our findings suggest a molecular TLR2/1-dependent conversation between highly pure activated microglia and astrocytes via signaling molecules. Furthermore, we demonstrate the first crosstalk experiments using ∼100% pure microglia and astrocyte mono-/co-cultures derived from mice with different genotypes highlighting the urgent need of efficient glial isolation protocols, which particularly holds true for astrocytes.
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Affiliation(s)
- Laura Zelenka
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Michael Jarek
- Helmholtz Centre for Infection Research, Research Group Genome Analytics (GMAK), Braunschweig, Germany
| | - Dennis Pägelow
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Robert Geffers
- Helmholtz Centre for Infection Research, Research Group Genome Analytics (GMAK), Braunschweig, Germany
| | - Kira van Vorst
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany
| | - Marcus Fulde
- Centre for Infection Medicine, Institute of Microbiology and Epizootics, Freie Universität Berlin, Berlin, Germany.
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Shi JM, Liu H, Cai L, Guo YB, Ma H, Li YS, Li SD, Zhang ZY, Ma YD, Guo CH. Identification and functional comparison of primary astrocytes and microglia. J Neurosci Methods 2023; 383:109731. [PMID: 36283489 DOI: 10.1016/j.jneumeth.2022.109731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2022] [Revised: 10/18/2022] [Accepted: 10/21/2022] [Indexed: 11/05/2022]
Affiliation(s)
- Jing-Ming Shi
- Key Laboratory for Molecular Genetic Mechanisms and Intervention Research on High Altitude Disease of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xian Yang, Shaanxi Province 712082, China.
| | - Hang Liu
- Key Laboratory for Molecular Genetic Mechanisms and Intervention Research on High Altitude Disease of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xian Yang, Shaanxi Province 712082, China
| | - Long Cai
- Maternity and Children's Hospital of Tibet Autonomous Region, Lhasa, Tibet Autonomous Region 850000, China
| | - Yi-Bo Guo
- Key Laboratory for Molecular Genetic Mechanisms and Intervention Research on High Altitude Disease of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xian Yang, Shaanxi Province 712082, China
| | - Hui Ma
- Key Laboratory for Molecular Genetic Mechanisms and Intervention Research on High Altitude Disease of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xian Yang, Shaanxi Province 712082, China
| | - Yan-Song Li
- Key Laboratory for Molecular Genetic Mechanisms and Intervention Research on High Altitude Disease of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xian Yang, Shaanxi Province 712082, China
| | - Sha-Di Li
- Key Laboratory for Molecular Genetic Mechanisms and Intervention Research on High Altitude Disease of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xian Yang, Shaanxi Province 712082, China
| | - Ze-Yu Zhang
- Key Laboratory for Molecular Genetic Mechanisms and Intervention Research on High Altitude Disease of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xian Yang, Shaanxi Province 712082, China
| | - Yan-Dong Ma
- Key Laboratory for Molecular Genetic Mechanisms and Intervention Research on High Altitude Disease of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xian Yang, Shaanxi Province 712082, China
| | - Cheng-Hui Guo
- Key Laboratory for Molecular Genetic Mechanisms and Intervention Research on High Altitude Disease of Tibet Autonomous Region, School of Medicine, Xizang Minzu University, Xian Yang, Shaanxi Province 712082, China
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Buenaventura RG, Harvey AC, Burns MP, Main BS. Sequential Isolation of Microglia and Astrocytes from Young and Aged Adult Mouse Brains for Downstream Transcriptomic Analysis. Methods Protoc 2022; 5:77. [PMID: 36287049 PMCID: PMC9610580 DOI: 10.3390/mps5050077] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2022] [Revised: 09/21/2022] [Accepted: 09/23/2022] [Indexed: 11/17/2022] Open
Abstract
In aging, the brain is more vulnerable to injury and neurodegenerative disease, but the mechanisms responsible are largely unknown. Evidence now suggests that neuroinflammation, mediated by resident brain astrocyte and microglia populations, are key players in the generation of inflammatory responses and may influence both age related processes and the initiation/progression of neurodegeneration. Consequently, targeting these cell types individually and collectively may aid in the development of novel disease-modifying therapies. We have optimized and characterized a protocol for the effective sequential isolation of both microglia and astrocytes from the adult mouse brain in young and aged mice. We demonstrate a technique for the sequential isolation of these immune cells by using magnetic beads technology, optimized to increase yield and limit potential artifacts in downstream transcriptomic applications, including RNA-sequencing pipelines. This technique is versatile, cost-effective, and reliable for the study of responses within the same biological context, simultaneously being advantageous in reducing mice numbers required to assess cellular responses in normal and age-related pathological conditions.
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Affiliation(s)
| | | | | | - Bevan S. Main
- Department of Neuroscience, Georgetown University Medical Center, Washington, DC 20057, USA
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