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Green TRF, Rowe RK. Quantifying microglial morphology: an insight into function. Clin Exp Immunol 2024; 216:221-229. [PMID: 38456795 PMCID: PMC11097915 DOI: 10.1093/cei/uxae023] [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: 08/09/2023] [Revised: 01/17/2024] [Accepted: 03/06/2024] [Indexed: 03/09/2024] Open
Abstract
Microglia are specialized immune cells unique to the central nervous system (CNS). Microglia have a highly plastic morphology that changes rapidly in response to injury or infection. Qualitative and quantitative measurements of ever-changing microglial morphology are considered a cornerstone of many microglia-centric research studies. The distinctive morphological variations seen in microglia are a useful marker of inflammation and severity of tissue damage. Although a wide array of damage-associated microglial morphologies has been documented, the exact functions of these distinct morphologies are not fully understood. In this review, we discuss how microglia morphology is not synonymous with microglia function, however, morphological outcomes can be used to make inferences about microglial function. For a comprehensive examination of the reactive status of a microglial cell, both histological and genetic approaches should be combined. However, the importance of quality immunohistochemistry-based analyses should not be overlooked as they can succinctly answer many research questions.
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Affiliation(s)
- Tabitha R F Green
- Department of Integrative Physiology, The University of Colorado Boulder, Boulder, CO, USA
| | - Rachel K Rowe
- Department of Integrative Physiology, The University of Colorado Boulder, Boulder, CO, USA
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Petrican R, Fornito A, Boyland E. Lifestyle Factors Counteract the Neurodevelopmental Impact of Genetic Risk for Accelerated Brain Aging in Adolescence. Biol Psychiatry 2024; 95:453-464. [PMID: 37393046 DOI: 10.1016/j.biopsych.2023.06.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 05/30/2023] [Accepted: 06/19/2023] [Indexed: 07/03/2023]
Abstract
BACKGROUND The transition from childhood to adolescence is characterized by enhanced neural plasticity and a consequent susceptibility to both beneficial and adverse aspects of one's milieu. METHODS To understand the implications of the interplay between protective and risk-enhancing factors, we analyzed longitudinal data from the Adolescent Brain Cognitive Development (ABCD) Study (n = 834; 394 female). We probed the maturational correlates of positive lifestyle variables (friendships, parental warmth, school engagement, physical exercise, healthy nutrition) and genetic vulnerability to neuropsychiatric disorders (major depressive disorder, Alzheimer's disease, anxiety disorders, bipolar disorder, schizophrenia) and sought to further elucidate their implications for psychological well-being. RESULTS Genetic risk factors and lifestyle buffers showed divergent relationships with later attentional and interpersonal problems. These effects were mediated by distinguishable functional neurodevelopmental deviations spanning the limbic, default mode, visual, and control systems. More specifically, greater genetic vulnerability was associated with alterations in the normative maturation of areas rich in dopamine (D2), glutamate, and serotonin receptors and of areas with stronger expression of astrocytic and microglial genes, a molecular signature implicated in the brain disorders discussed here. Greater availability of lifestyle buffers predicted deviations in the normative functional development of higher density GABAergic (gamma-aminobutyric acidergic) receptor regions. The two profiles of neurodevelopmental alterations showed complementary roles in protection against psychopathology, which varied with environmental stress levels. CONCLUSIONS Our results underscore the importance of educational involvement and healthy nutrition in attenuating the neurodevelopmental sequelae of genetic risk factors. They also underscore the importance of characterizing early-life biomarkers associated with adult-onset pathologies.
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Affiliation(s)
- Raluca Petrican
- Institute of Population Health, Department of Psychology, University of Liverpool, Liverpool, United Kingdom.
| | - Alex Fornito
- Turner Institute for Brain and Mental Health, School of Psychological Sciences, Monash Biomedical Imaging, Monash University, Melbourne, Victoria, Australia
| | - Emma Boyland
- Institute of Population Health, Department of Psychology, University of Liverpool, Liverpool, United Kingdom
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Virtuoso A, Galanis C, Lenz M, Papa M, Vlachos A. Regional Microglial Response in Entorhino-Hippocampal Slice Cultures to Schaffer Collateral Lesion and Metalloproteinases Modulation. Int J Mol Sci 2024; 25:2346. [PMID: 38397023 PMCID: PMC10889226 DOI: 10.3390/ijms25042346] [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: 01/12/2024] [Revised: 02/08/2024] [Accepted: 02/13/2024] [Indexed: 02/25/2024] Open
Abstract
Microglia and astrocytes are essential in sustaining physiological networks in the central nervous system, with their ability to remodel the extracellular matrix, being pivotal for synapse plasticity. Recent findings have challenged the traditional view of homogenous glial populations in the brain, uncovering morphological, functional, and molecular heterogeneity among glial cells. This diversity has significant implications for both physiological and pathological brain states. In the present study, we mechanically induced a Schaffer collateral lesion (SCL) in mouse entorhino-hippocampal slice cultures to investigate glial behavior, i.e., microglia and astrocytes, under metalloproteinases (MMPs) modulation in the lesioned area, CA3, and the denervated region, CA1. We observed distinct response patterns in the microglia and astrocytes 3 days after the lesion. Notably, GFAP-expressing astrocytes showed no immediate changes post-SCL. Microglia responses varied depending on their anatomical location, underscoring the complexity of the hippocampal neuroglial network post-injury. The MMPs inhibitor GM6001 did not affect microglial reactions in CA3, while increasing the number of Iba1-expressing cells in CA1, leading to a withdrawal of their primary branches. These findings highlight the importance of understanding glial regionalization following neural injury and MMPs modulation and pave the way for further research into glia-targeted therapeutic strategies for neurodegenerative disorders.
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Affiliation(s)
- Assunta Virtuoso
- Neuronal Morphology Networks and Systems Biology Laboratory, Division of Human Anatomy, Department of Mental and Physical Health and Preventive Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (C.G.); (A.V.)
| | - Christos Galanis
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (C.G.); (A.V.)
| | - Maximilian Lenz
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (C.G.); (A.V.)
- Hannover Medical School, Institute of Neuroanatomy and Cell Biology, 30625 Hannover, Germany
| | - Michele Papa
- Neuronal Morphology Networks and Systems Biology Laboratory, Division of Human Anatomy, Department of Mental and Physical Health and Preventive Medicine, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany; (C.G.); (A.V.)
- Center for Basics in NeuroModulation (NeuroModulBasics), Faculty of Medicine, University of Freiburg, 79106 Freiburg, Germany
- Center BrainLinks–BrainTools, University of Freiburg, 79110 Freiburg, Germany
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Sun Y, Che J, Zhang J. Emerging non-proinflammatory roles of microglia in healthy and diseased brains. Brain Res Bull 2023; 199:110664. [PMID: 37192719 DOI: 10.1016/j.brainresbull.2023.110664] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 04/04/2023] [Accepted: 05/13/2023] [Indexed: 05/18/2023]
Abstract
Microglia, the resident myeloid cells of the central nervous system, are the first line of defense against foreign pathogens, thereby confining the extent of brain injury. However, the role of microglia is not limited to macrophage-like functions. In addition to proinflammatory response mediation, microglia are involved in neurodevelopmental remodeling and homeostatic maintenance in the absence of disease. An increasing number of studies have also elucidated microglia-mediated regulation of tumor growth and neural repair in diseased brains. Here, we review the non-proinflammatory roles of microglia, with the aim of promoting a deeper understanding of the functions of microglia in healthy and diseased brains and contributing to the development of novel therapeutics that target microglia in neurological disorders.
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Affiliation(s)
- Yinying Sun
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, 200032, Shanghai China.
| | - Ji Che
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, 200032, Shanghai China.
| | - Jun Zhang
- Department of Anesthesiology, Fudan University Shanghai Cancer Center, 200032, Shanghai China; Department of Oncology, Shanghai Medical College, Fudan University, 200032, Shanghai China.
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Govic A, Nasser H, Levay EA, Zelko M, Ebrahimie E, Mohammadi Dehcheshmeh M, Kent S, Penman J, Hazi A. Long-Term Calorie Restriction Alters Anxiety-like Behaviour and the Brain and Adrenal Gland Transcriptomes of the Ageing Male Rat. Nutrients 2022; 14:nu14214670. [PMID: 36364936 PMCID: PMC9654051 DOI: 10.3390/nu14214670] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 10/28/2022] [Accepted: 11/01/2022] [Indexed: 11/06/2022] Open
Abstract
Further examination of the molecular regulators of long-term calorie restriction (CR), reported to have an anxiolytic effect, may highlight novel therapeutic targets for anxiety disorders. Here, adult male Hooded Wistar rats were exposed to a 25% CR whilst anxiety-like behaviour was assessed at 6-, 12-, and 18-months of age via the elevated plus maze, open field, and acoustic startle tests. Next-generation sequencing was then used to measure transcriptome-wide gene expression in the hypothalamus, amygdala, pituitary, and adrenal glands. Results showed an anxiolytic behavioural profile across early, middle, and late adulthood by CR, with the strongest effects noted at 6-months. Transcriptomic analysis by seven attribute weighting algorithms, including Info Gain Ratio, Rule, Chi Squared, Gini Index, Uncertainty, Relief, and Info Gain, led to the development of a signature of long-term CR, independent of region. Complement C1q A chain (C1qa), an extracellular protein, expression was significantly decreased by CR in most regions examined. Furthermore, text mining highlighted the positive involvement of C1qa in anxiety, depression, neurodegeneration, stress, and ageing, collectively identifying a suitable biomarker candidate for CR. Overall, the current study identified anxiety-related phenotypic changes and a novel transcriptome signature of long-term CR, indicating potential therapeutic targets for anxiety, depression, and neurodegeneration.
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Affiliation(s)
- Antonina Govic
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC 3010, Australia
- Epigenes Australia Pty Ltd., Melbourne, VIC 3010, Australia
- Correspondence: or ; Tel.: +61-3-9780-9996
| | - Helen Nasser
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC 3010, Australia
- Epigenes Australia Pty Ltd., Melbourne, VIC 3010, Australia
| | - Elizabeth A. Levay
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC 3010, Australia
- Epigenes Australia Pty Ltd., Melbourne, VIC 3010, Australia
| | - Matt Zelko
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC 3010, Australia
- Epigenes Australia Pty Ltd., Melbourne, VIC 3010, Australia
| | - Esmaeil Ebrahimie
- Genomics Research Platform, School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, VIC 3000, Australia
- School of Animal and Veterinary Sciences, The University of Adelaide, Adelaide, SA 5371, Australia
- School of BioSciences, The University of Melbourne, Melbourne, VIC 3010, Australia
| | - Manijeh Mohammadi Dehcheshmeh
- Genomics Research Platform, School of Agriculture, Biomedicine and Environment, La Trobe University, Melbourne, VIC 3000, Australia
- School of Animal and Veterinary Sciences, The University of Adelaide, Adelaide, SA 5371, Australia
| | - Stephen Kent
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC 3010, Australia
| | - Jim Penman
- Epigenes Australia Pty Ltd., Melbourne, VIC 3010, Australia
| | - Agnes Hazi
- School of Psychology and Public Health, La Trobe University, Melbourne, VIC 3010, Australia
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Zhang Y, Dong Y, Zhu Y, Sun D, Wang S, Weng J, Zhu Y, Peng W, Yu B, Jiang Y. Microglia-specific transcriptional repression of interferon-regulated genes after prolonged stress in mice. Neurobiol Stress 2022; 21:100495. [DOI: 10.1016/j.ynstr.2022.100495] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Revised: 09/27/2022] [Accepted: 09/29/2022] [Indexed: 11/25/2022] Open
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