Microglial subtypes: diversity within the microglial community

The EMBO Journal, Journal Year: 2019, Volume and Issue: 38(17)

Published: Aug. 2, 2019

Review2 August 2019Open Access Microglial subtypes: diversity within the microglial community Vassilis Stratoulias orcid.org/0000-0002-9724-6589 Toxicology Unit, Institute of Environmental Medicine, Karolinska Institutet, Stockholm, Sweden Search for more papers by this author Jose Luis Venero Departamento de Bioquímica y Biología Molecular, Facultad Farmacia, Universidad Sevilla, Spain Instituto Biomedicina Sevilla-Hospital Universitario Virgen del Rocío/CSIC/Universidad Marie-Ève Tremblay Department Molecular Université Laval, Quebec, QC, Canada Axe Neurosciences, Centre Recherche du CHU Québec-Université Bertrand Joseph Corresponding Author [email protected] orcid.org/0000-0001-5655-9979 Information Stratoulias1, Venero2,3, Tremblay4,5 and *,1 1Toxicology 2Departamento 3Instituto 4Department 5Axe *Corresponding author. Tel: +46 703057405; E-mail: The EMBO Journal (2019)38:e101997https://doi.org/10.15252/embj.2019101997 PDFDownload PDF article text main figures. ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinked InMendeleyWechatReddit Figures & Info Abstract Microglia are brain-resident macrophages forming first active immune barrier in central nervous system. They fulfill multiple functions across development adulthood under disease conditions. Current understanding revolves around microglia acquiring distinct phenotypes upon exposure extrinsic cues their environment. However, emerging evidence suggests that display differences not exclusively driven milieu, rather unique properties these cells possess. This intrinsic heterogeneity has been largely overlooked, favoring prevailing view a single-cell type endowed with spectacular plasticity, allowing them acquire thereby numerous health disease. Here, we review might form which each member (or "subtype") displays performs functions. Distinctive features functional implications several subtypes considered, contexts Finally, suggest subtype categorization shall be based on function propose ways studying them. Hence, advocate plasticity (reaction states) (subtypes) should both considered when multitasking microglia. Introduction were introduced scientific literature century ago (Río-Hortega, 1919a,1919b,1919c; Fig 1). During normal physiological conditions, ramified morphology regularly distributed throughout system (CNS; Río-Hortega, 1919b). Upon pathology, transform function, leading cascade "reaction" from hypertrophic ameboid still orients research today (Flanary et al, 2007; Graeber, 2010; With recent advances genetic tools fate mapping (Ginhoux 2010), now tissue-resident CNS arise embryonic yolk sac (Alliot 1999; Schulz 2012; Kierdorf 2013; Perdiguero 2015). colonize murine day (E)9.5 (Tay 2017c) represent self-maintaining long-lived cell population persists months, if entire lifespan organism (Lawson 1992; Ajami 2007, 2011; Mildner Askew 2017; Füger Réu Tay 2017b). Beyond functioning as mediators injury, inflammation, neurodegeneration, roles healthy brain have identified at an exponential rate past decade (Cartier 2014; 2015; Figure 1. Historical overview identificationAlthough originally proposed Rio-Hortega report microglia, it was only recently idea revisited. Download figure PowerPoint exhibit widely differing depending stage life, region, context or Differences number, morphology, gene expression also reported between sexes (Schwarz Crain Lenz Pimentel-Coelho Butovsky Dorfman Hanamsagar Krasemann 2017). Adequate crucial behavioral adaptation environment (Salter Stevens, 2017a). Throughout contribute neurogenesis, neuronal circuit shaping, vascular formation remodeling, maintenance homeostasis 2017c). aging diseases, may become reactive impaired surveillance phagocytosis (Streit, 2002; Koellhoffer Spittau, contribution diseases is associated compromised (e.g., synaptic plasticity; 2017a) processes adaptive brain, yet death tissue damage pathological settings excitotoxicity, oxidative stress, inflammation; Weil 2008). reaction can triggered any kind insults disturbances CNS. Persisting reaction, often proliferation, involved conditions ranging neurodevelopmental disorders, traumatic injuries, infectious tumors, psychiatric neurodegenerative diseases. Depending stressor insult play, process shown proceed differently result sometimes contrasting outcomes (see 2A classical schematic representation, depicting gray surrounded palette colorful representing state). It recognized wide range states, tremendous shift M1/M2 classification used few years (Martinez Gordon, Ransohoff, 2016). According view, would fulfilled through toward phenotypes, molecular signature (Crain Hickman Bennett 2016; Grabert Flowers Galatro Keren-Shaul Hammond 2018; Masuda 2019). pieces indicate different pools acquired during maturation These co-exist steady state undergo further modulation phenotypic transformation response stimuli (Fig 2B). Indeed, beyond adopts stimuli, constitute members properties, perform functions, respond 2C). We distinctive putative "subtypes", structural, ultrastructural, levels, well Furthermore, categorize than signatures markers. candidates validated using methodological workflow recommend. 2. states(A) Currently, homogenous cellular (core circle gray) extremely plastic. status given developmental resulting invariably assume described literature. (B) In updated version here, heterogeneous having specializations. (C) environmental cue, stimulus, expanding and/or changing its specific phenotype. Microglia: fulfilling vast What defines subject intense debate, discussed Box 1 Accumulating indicates naïve responds identically possible assuming predetermined fact, historical perspective, notion had already 1919 his original description 1919b; He noticed some he named "satellite" found close proximity bodies. A later, satellite below, one playing cards deck 3). important acknowledge others, avant-garde scientists, paved way concept (McCluskey Lampson, 2000; Olah Hanisch, Gertig 2014). 1: How define "cell (sub)type" answer "how subtype?" probably closely related question, type?" Traditionally, defined host tissue, lineage, composition. definition term remains debate (Clevers advancement unbiased technologies transcriptome profiling, such high throughput RNAseq mass cytometry improved/related methods), revealed remarkable among traditionally homogeneous. whereas degree proteome sufficient defining subtypes, even topic (Trapnell, Okawa 2018). While allow molecularly subpopulations, approaches require complemented identification populations, order those (sub)types. Worth notice, importance confound states reaction. latter referring various stimuli. shared properties/characteristics other type. Their selective independent microenvironment. two concepts mutually exclusive, stimulus could react new phenotype, i.e., thus adding another level complexity. must steady-state unchallenged propertie(s) translate into function(s). Typically, existing foundation plan, biased respect studies aimed identifying subtype. includes work markers, most importantly staining, sorting, isolation cells. Reverse provide reliable tool studies, but they inherit technical limitations gating flow antibody unspecificity (Luo 2013). On hand, RNAseq, cytometry, electron microscopy useful tools, aware limitation terms providing static dynamics. however combined two-photon vivo imaging insights Serendipitous approach, sporadic non-systematic. All above methodologies subtypes. Considering review, need classifying evident. Deciphering whether variations instructed microenvironment prime importance, following workflow: Fate-mapping strategies visualize selectively subsets, instance non-invasive chronic imaging—could performed longitudinally development, adulthood, aging, conditions—to determine identity subsets phenotypes. remain examined longitudinally, instead another, notably determinants then studied combination protein analyses, ultrastructure, dynamic investigations. 3. Putative specializationsEmerging data support existence genomic, spatial, morphological, anticipate analyzing thoroughly, 1, similar methodology newly discovered ones, will number characteristics targeted prevention treatment. regional Although ubiquitously scattered CNS, distribution varies regions, white matter 1990). differs presence bodies, dendrites axons, myelinated blood vessels. self-renewal turnover rates lipopolysaccharide (LPS) challenge 2017b; Furube tightly transcriptional level, mouse human (Gosselin 2014, Direct variability comes isolated wild-type, adult mice, according area, determined panels pre-selected study, CD11b, CD40, CD45, CD80, CD86, F4/80, TREM2b, CX3CR1, CCR9 compared regions young mice (de Haas all markers expressed varied significantly areas. study rats, levels known showed region-specific profiles (Doorn Similar areas additionally pattern (Butovsky De Biase Additionally, RNA sequencing (RNAseq) cerebral hippocampal analyzed, 47 identified, including belonging (Zeisel findings raise intriguing possibility survival, activity, growth factor release, metabolism, myelination, blood–brain driving differentiation major contributing heterogeneity. Recently, cerebellar clearance ability, genes supporting engulfment catabolism debris (Ayata "type" reminiscent developing disease-associated (DAM) below. By contrast, striatum homeostatic epigenetic mechanisms particular, suppression striatal mediated PRC2, catalyzes repressive chromatin modification histone H3 lysine 27 trimethylation (H3K27me3). ablation PRC2 results emergence absence dying neurons, cortex. aberrant induce motor responses, decreased learning memory, together anxiety seizures characterized CNS-associated (CAM) three CAM Mrc1, Ms4at, Pf4, Stab1, Cbr2, CD163, Fcrls, compartments: leptomeninges, choroid plexus, perivascular space (Jordão Consequently, partly accounted diversity. differential expressions Differential established approach subpopulations type, GABAergic glutamatergic) observed brain. contexts, neighboring state. local cues, interactions neurons inhibitory excitatory) glial (astrocytes, oligodendrocytes, progenitors), slight signaling thresholds. Similarly, peripheral macrophage activation LPS viruses described, where subset concomitantly (Ravasi 2002). addition, directly communicate other, recruitment lead inhibition initially occupying non-overlapping territories changing, improved staining methods showing direct contacts bodies neighbor (for example, see Milior marker adjacent previous challenges considered. For instance, laser injury intact, converging site (Nimmerjahn 2005; Paris migrate cortex (Eyo 2018) cerebellum (Stowell paints layer expression, cannot excluded argue deserves investigation. below: Keratan sulfate proteoglycan (KSPG)-microglia quarter ago, rat constitutive KSPG (Bertolotto 1993), visualized situ 5D4 monoclonal located extracellular matrix surface. suggested control adhesion axonal growth. 5D4-KSPG subpopulation contrary 1993, 1998). Of note, does coincide GFAP, NG2, MAP2, relate strains inbred rats (Jander Stoll, 1996b). mammals, 5D4-KSPG-expressing spinal cord retina 1998; Jander 1996a; Jones Tuszynski, Zhang Foyez 5D4-KSPG-microglia preferential large numbers hippocampus, brainstem, olfactory bulb (OB), detected neonatal mention 5D4-KSPG-negative same (Jones KSPG-reactivity, systematic required confirm 4). 4.Toolbox. Hox8b-microglia differentiates canonical population, spatial temporal 2 ontogeny Hoxb8-microglia). Mice carrying driver Hoxb8-Cre reporter ROSA26-YFP alleles crossed trace YFP-Hoxb8 expression. YFP signal appeared YFP-positive especially OB (Chen 25–40% total YFP-negative Nagarajan Transcriptomic analyses comparing Hoxb8-positive Hoxb8-negative very state, 21 populations (De Hoxb8-microglia express genes, Tmem119, Sall1, Sall3, Gpr56, Ms4a7, hematopoietic Clel12a, Klra2, Lilra5 non-Hoxb8 (Bennett neither expresses Hoxb8 brain; instead, lineage tracer progenitors prior infiltration Selective inactivation grooming behavior, mutant strategy deletion included use Tie2 Cre affect endothelial 2010). More cell-specific prerequisite involvement behavior. (with illustration): Revisiting origin(s) An question arising relates origin(s). Do possess populating do once assumed parenchyma? convincingly derive wave hematopoiesis Hoeffel Sheng Mass 2016), follow stepwise program (Mass Matcovitch-Natan before E9.5 Based literature, differentiate inside parenchyma (a). hypothesis explain microenvironments (inhibitory, oligodendrocytes thresholds, alternative exhibiting infiltrating early investigation, tested (b c). later hypothesis, Capecchi al Hoxb8-microglia-progenitors exist E8.5 Subsequently, transit aorta-gonad-mesonephros fetal liver, expand entry E12.5 (c). lines, CSF1R−/− Erblich 2011) IL2-Tgfb1;Tgfb1−/− (Keren-Shaul 2017) transgenic expected parenchyma. E14.5 exist, Ms4a7 (Hammond great interest investigate subpopulations. zebrafish, waves (Xu Ferrero yolk-sac-equivalent structure origin populate replenished zebrafish (d). div

Language: Английский

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Polyglutamine-Expanded Huntingtin Exacerbates Age-Related Disruption of Nuclear Integrity and Nucleocytoplasmic Transport

Neuron, Journal Year: 2017, Volume and Issue: 94(1), P. 48 - 57.e4

Published: April 1, 2017

Language: Английский

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Distinction of Neurons, Glia and Endothelial Cells in the Cerebral Cortex: An Algorithm Based on Cytological Features

Frontiers in Neuroanatomy, Journal Year: 2016, Volume and Issue: 10

Published: Nov. 1, 2016

The estimation of the number or density neurons and types glial cells their relative proportions in different brain areas are at core rigorous quantitative neuroanatomical studies. Unfortunately, lack detailed, updated, systematic well-illustrated descriptions cytology cell types, especially primate brain, makes such studies demanding, often limiting scope broad use. Here, following an extensive analysis histological materials review current classical literature, we compile a list precise morphological criteria that can facilitate standardize identification stained sections examined under microscope. We describe systematically detail cytological features cerebral cortex macaque monkey human using semithin thick for Nissl. used this staining technique because it labels all distinct ways. In addition, corroborate key distinguishing characteristics immunolabeled specific markers counterstained Nissl ultrathin processed electron microscopy. Finally, summarize distinguish each type easy-to-use tables sketches, structure these algorithm be to cellular cortex. Moreover, report high inter-observer reliability, which is crucial test obtaining consistent reproducible counts unbiased stereological This protocol establishes framework reliably identify quantify primates as well other mammalian species health disease.

Language: Английский

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Spread of aggregates after olfactory bulb injection of α-synuclein fibrils is associated with early neuronal loss and is reduced long term

Acta Neuropathologica, Journal Year: 2017, Volume and Issue: 135(1), P. 65 - 83

Published: Dec. 5, 2017

Parkinson's disease is characterized by degeneration of substantia nigra dopamine neurons and intraneuronal aggregates, primarily composed misfolded α-synuclein. The α-synuclein aggregates in patients are suggested to first appear the olfactory bulb enteric nerves then propagate, following a stereotypic pattern, via neural pathways numerous regions across brain. We recently demonstrated that after injection either mouse or human fibrils into wild-type mice, recruited endogenous pathological spread transneuronally over 40 other brain subregions, 12 months. previously reported progressive spreading between 1 months fibril injections, now report how far pathology has 18- 23-month post-injection this model. Our data show 18 months, there further increase number exhibiting human, lesser extent mouse, injections. At both 23 fibrils, we observed reduction density some compared others at no additional exhibited earlier time points. In addition, also demonstrate induced α-synucleinopathy triggered significant early neuron loss anterior nucleus. By contrast, was mitral bulb, even month post-injection. speculate lack continued progression due compromise circuitry, consequential possibly activation proteolytic mechanisms resilient mice counterbalances seeding degrading pathogenic

Language: Английский

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Deep learning-based predictive identification of neural stem cell differentiation

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: May 10, 2021

Abstract The differentiation of neural stem cells (NSCs) into neurons is proposed to be critical in devising potential cell-based therapeutic strategies for central nervous system (CNS) diseases, however, the determination and prediction complex not yet clearly established, especially at early stage. We hypothesize that deep learning could extract minutiae from large-scale datasets, present a network model predictable reliable identification NSCs fate. Remarkably, using only bright field images without artificial labelling, our surprisingly effective identifying differentiated cell types, even as 1 day culture. Moreover, approach showcases superior precision robustness designed independent test scenarios involving various inducers, including neurotrophins, hormones, small molecule compounds nanoparticles, suggesting excellent generalizability applicability. anticipate accurate robust learning-based platform will accelerate progress applications.

Language: Английский

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A meta-analysis of epigenome-wide association studies in Alzheimer’s disease highlights novel differentially methylated loci across cortex

Nature Communications, Journal Year: 2021, Volume and Issue: 12(1)

Published: June 10, 2021

Abstract Epigenome-wide association studies of Alzheimer’s disease have highlighted neuropathology-associated DNA methylation differences, although existing been limited in sample size and utilized different brain regions. Here, we combine data from six methylomic ( N = 1453 unique individuals) to identify differential associated with Braak stage regions across cortex. We 236 CpGs the prefrontal cortex, 95 temporal gyrus ten entorhinal cortex at Bonferroni significance, none cerebellum. Our cross-cortex meta-analysis 1408 donors) identifies 220 neuropathology, annotated 121 genes, which 84 genes not previously reported this significance threshold. replicated our findings using two further datasets consisting a >600 donors. The summary statistics are available online resource www.epigenomicslab.com/ad-meta-analysis/ ).

Language: Английский

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Engineered virus-like particles for transient delivery of prime editor ribonucleoprotein complexes in vivo

Nature Biotechnology, Journal Year: 2024, Volume and Issue: 42(10), P. 1526 - 1537

Published: Jan. 8, 2024

Prime editing enables precise installation of genomic substitutions, insertions and deletions in living systems. Efficient vitro vivo delivery prime components, however, remains a challenge. Here we report editor engineered virus-like particles (PE-eVLPs) that deliver proteins, guide RNAs nicking single as transient ribonucleoprotein complexes. We systematically v3 v3b PE-eVLPs with 65- to 170-fold higher efficiency human cells compared PE-eVLP construct based on our previously reported base eVLP architecture. In two mouse models genetic blindness, injections resulted therapeutically relevant levels the retina, protein expression restoration partial visual function rescue. Optimized support ribonucleoproteins, enhancing potential safety by reducing off-target obviating possibility oncogenic transgene integration.

Language: Английский

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Dihydrolipoic Acid–Gold Nanoclusters Regulate Microglial Polarization and Have the Potential To Alter Neurogenesis

Nano Letters, Journal Year: 2019, Volume and Issue: 20(1), P. 478 - 495

Published: Nov. 30, 2019

Microglia-mediated neuroinflammation is one of the most significant features in a variety central nervous system (CNS) disorders such as traumatic brain injury, stroke, and many neurodegenerative diseases. Microglia become polarized upon stimulation. The two extremes polarization are neuron-destructive proinflammatory M1-like neuron-regenerative M2-like phenotypes. Thus, manipulating microglial toward M2 phenotype promising therapeutic approach for CNS repair regeneration. It has been reported that nanoparticles potential tools regulating polarization. Gold nanoclusters (AuNCs) could penetrate blood–brain barrier have neuroprotective effects, suggesting possibility utilizing AuNCs to regulate improve neuronal regeneration CNS. In current study, functionalized with dihydrolipoic acid (DHLA–AuNCs), an antioxidant demonstrated roles, were prepared, their effects on cell line (BV2) examined. DHLA–AuNCs effectively suppressed processes BV2 cells by inducing phenotype. This was associated decrease reactive oxygen species reduced NF-kB signaling improvement survival coupled enhanced autophagy inhibited apoptosis. Conditioned medium from DHLA–AuNC-treated able enhance neurogenesis both N2a ex vivo slice stroke model. direct treatment slices also ameliorated stroke-related tissue injury astrocyte activation (astrogliosis). study suggests regeneration, be agent disorders.

Language: Английский

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CNS Transduction Benefits of AAV-PHP.eB over AAV9 Are Dependent on Administration Route and Mouse Strain

Molecular Therapy — Methods & Clinical Development, Journal Year: 2020, Volume and Issue: 19, P. 447 - 458

Published: Oct. 20, 2020

Adeno-associated viral (AAV) vectors are attractive tools for central nervous system (CNS) gene therapy because some can cross the blood-brain barrier (BBB), allowing them to be used as minimally invasive treatments. A novel AAV vector recently evolved in vivo, AAV-PHP.eB, has been reported BBB more effectively than existing gold standard AAV9, but not under all conditions. Here, we compared efficacy of single-stranded AAV-PHP.eB and AAV9 targeting mouse CNS peripheral tissues after administration via various routes, two different strains (C57BL/6J B6C3), packaging with a self-complementary genome. We found that produced higher transduction intravenous injection, only C57BL/6J B6C3 mice. similar when route did require BBB. Packaging genome increased overall transduction, at expense strong neuronal tropism. resulted less liver tissue Taken together, these results suggest potential applications, consideration will required translation beyond models.

Language: Английский

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Cell type-specific epigenetic links to schizophrenia risk in the brain

Genome biology, Journal Year: 2019, Volume and Issue: 20(1)

Published: July 9, 2019

The importance of cell type-specific epigenetic variation non-coding regions in neuropsychiatric disorders is increasingly appreciated, yet data from disease brains are conspicuously lacking. We generate whole-genome methylomes (N = 95) and transcriptomes 89) neurons oligodendrocytes obtained brain tissue patients with schizophrenia matched controls.The the two types highly distinct, majority differential DNA methylation occurring regions. differences between cases controls subtle compared to type differences, robust against permuted validated targeted deep-sequencing analyses. Differential control tends occur differentially methylated sites, highlighting significance dysregulation a complex disorder.Our results provide novel comprehensive methylome transcriptome distinct populations within patient-derived tissues. This clearly demonstrate that epigenetic-differentiated sites preferentially by disease-associated dysregulation. further show reduced distinction schizophrenia.

Language: Английский

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