Peripherally derived macrophages can engraft the brain independent of irradiation and maintain an identity distinct from microglia
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE84819 | GEO | 2018/04/07
REPOSITORIES: GEO
Similar Datasets
Project description:Peripherally derived macrophages infiltrate the brain after bone marrow transplantation and during central nervous system (CNS) inflammation. It was initially suggested that these engrafting cells were newly derived microglia and that irradiation was essential for engraftment to occur. However, it remains unclear whether brain-engrafting macrophages (beMφs) acquire a unique phenotype in the brain, whether long-term engraftment may occur without irradiation, and whether brain function is affected by the engrafted cells. In this study, we demonstrate that chronic, partial microglia depletion is sufficient for beMφs to populate the niche and that the presence of beMφs does not alter behavior. Furthermore, beMφs maintain a unique functional and transcriptional identity as compared with microglia. Overall, this study establishes beMφs as a unique CNS cell type and demonstrates that therapeutic engraftment of beMφs may be possible with irradiation-free conditioning regimens.
2018-04-07 | GSE108575 | GEO
Project description:Peripherally derived macrophages infiltrate the brain after bone marrow transplantation and during central nervous system (CNS) inflammation. It was initially suggested that these engrafting cells were newly derived microglia and that irradiation was essential for engraftment to occur. However, it remains unclear whether brain-engrafting macrophages (beMφs) acquire a unique phenotype in the brain, whether long-term engraftment may occur without irradiation, and whether brain function is affected by the engrafted cells. In this study, we demonstrate that chronic, partial microglia depletion is sufficient for beMφs to populate the niche and that the presence of beMφs does not alter behavior. Furthermore, beMφs maintain a unique functional and transcriptional identity as compared with microglia. Overall, this study establishes beMφs as a unique CNS cell type and demonstrates that therapeutic engraftment of beMφs may be possible with irradiation-free conditioning regimens.
2018-04-07 | GSE108569 | GEO
Project description:Expression profiling of distinct central nervous system (CNS) cell populations has been employed to facilitate disease classification and to provide insights into the molecular basis of brain pathology. One important cell type implicated in a wide variety of CNS disease states is the resident brain macrophage (microglia). In these studies, microglia are often isolated from dissociated brain tissue by flow sorting procedures [fluorescence-activated cell sorting (FACS)] or from postnatal glial cultures by mechanic isolation. Given the highly dynamic and state-dependent functions of these cells, the use of FACS or short-term culture methods may not accurately capture the biology of brain microglia. In the current study, we performed RNA-sequencing using Cx3cr1+/GFP labeled microglia isolated from the brainstem of 6-week-old mice to compare the transcriptomes of FACS-sorted versus laser capture microdissection (LCM). While both isolation techniques resulted in a large number of shared (common) transcripts, we identified transcripts unique to FACS-isolated and LCM-captured microglia. In particular, M-bM-^HM-<50% of these LCM-isolated microglial transcripts represented genes typically associated with neurons and glia. While these transcripts clearly localized to microglia using complementary methods, they were not translated into protein. Following the induction of murine experimental autoimmune encephalomyelitis, increased oligodendrocyte and neuronal transcripts were detected in microglia, while only the myelin basic protein oligodendrocyte transcript was increased in microglia after traumatic brain injury. Collectively, these findings have implications for the design and interpretation of microglia transcriptome-based investigations. Wildtype and GFP expressing microglia from mouse brainstems were flow sorted or captured by laser microdissection. Differences between the two isolation methods were verified and further examined in neurodegenerative disease models.
2015-01-30 | E-GEOD-53789 | biostudies-arrayexpress
Project description:A major challenge in bone allogeneic marrow (BM) transplantation is overcoming engraftment resistance to avoid the clinical problem of graft rejection. Identifying genes and pathways that regulate BM engraftment may reveal molecular targets for overcoming these engraftment barriers. Previously, we developed a mouse model of BM transplantation that utilizes recipient conditioning with non-myeloablative total body irradiation followed by transplantation of allogeneic BM cells. We defined TBI doses that lead to graft rejection, that are permissive for engraftment, and mouse strain variation with regards to the permissive TBI dose. We now report gene expression analysis, using the Agilent Mouse 8x60K v3 expression arrays, in spleen of mice conditioned with TBI doses for evaluation in correlation to the expected engraftment phenotype. The spleens of mice given TBI demonstrated extensive differential gene expression, compared with un-irradiated controls, at both multiple testing-corrected P < .05 and fold change greater than or equal to 2 levels. Functional analysis revealed significant enrichment for up-regulation of canonical pathways involved in inflammation, even when treated with TBI doses not permissive for engraftment. Consistent with this the most significantly associated upstream regulators included lipopolysaccharide, tumor necrosis factor, and a toll-like receptor. Unique to engrafting mice, however, were enrichment for a down-regulated canonical pathway related to B-cell development. Results from this analysis have identified canonical pathways and upstream regulators of BM engraftment in mice and may lead to new approaches to overcome the problem of graft rejection complicating clinical BM transplantation. Each individual sample was pooled from 3 mice and performed in triplicate for each experimental group (TBI 300 cGy, 400 cGy, or 500 cGy) and for each strain mice (BALB.K or B10.BR) for statistical analysis. Additional arrays were perfromed for TBI 800 cGy (BALB.K) and TBI 900 cGy (B10.BR) for anlaysis of gene expressive after myeloablative condition.
2013-01-08 | E-GEOD-43310 | biostudies-arrayexpress
Project description:Whereas microglia involvement in virtually all brain diseases is well accepted their role for the control of homeostasis in the central nervous system (CNS) is mainly thought to maintain neuronal function through the formation, refinement and monitoring of synapses in both the developing and adult brain. Although the prenatal origin and the neuron-centered function of cortical microglia has recently been elucidated much less is known about a distinct amoeboid microglia population formerly described as “fountain of microglia” that appear only postnatally in the myelinating regions such as corpus callosum and cerebellum. Using large-scale transcriptional profiling, fate-mapping and genetic targeting approaches we identified a unique molecular signature of this microglia subset that arose from a CNS endogenous microglia pool independent from circulating myeloid cells. Microglia depletion experiments unexpectedly revealed an essential role of postnatal microglia for the proper development and homeostasis of oligodendrocytes. Our data provide new cellular and molecular insights into the myelin-supporting function of microglia in the normal CNS.
2017-07-19 | GSE96623 | GEO
Project description:Microglia, the resident macrophages of the central nervous system (CNS), engage in various CNS-specific functions that are critical for development and health. To better study the properties that distinguish microglia from other tissue macrophage populations, we have optimized serum-free culture conditions to permit robust survival of highly purified adult microglia under defined-medium conditions. We find that astrocyte-derived factors prevent microglial death ex vivo and that this activity results from three primary components (CSF-1/IL-34, TGF-b2, and cholesterol). Using microglial cultures that have never been exposed to serum, we demonstrate a dramatic change in intrinsic phagocytic capacity after serum exposure. Finally, we find that mature microglia rapidly lose signature gene expression profiles after isolation, and that this loss can be reversed by engrafting cells back into an intact CNS environment. These data indicate that the specialized gene expression profile of mature microglia require continuous instructive signaling from the intact CNS. This RNA-seq dataset describes changes in rat microglial transcriptome in culture with or without serum exposure.
2017-05-11 | GSE96995 | GEO
Project description:A major challenge in bone allogeneic marrow (BM) transplantation is overcoming engraftment resistance to avoid the clinical problem of graft rejection. Identifying genes and pathways that regulate BM engraftment may reveal molecular targets for overcoming these engraftment barriers. Previously, we developed a mouse model of BM transplantation that utilizes recipient conditioning with non-myeloablative total body irradiation followed by transplantation of allogeneic BM cells. We defined TBI doses that lead to graft rejection, that are permissive for engraftment, and mouse strain variation with regards to the permissive TBI dose. We now report gene expression analysis, using the Agilent Mouse 8x60K v3 expression arrays, in spleen of mice conditioned with TBI doses for evaluation in correlation to the expected engraftment phenotype. The spleens of mice given TBI demonstrated extensive differential gene expression, compared with un-irradiated controls, at both multiple testing-corrected P < .05 and fold change greater than or equal to 2 levels. Functional analysis revealed significant enrichment for up-regulation of canonical pathways involved in inflammation, even when treated with TBI doses not permissive for engraftment. Consistent with this the most significantly associated upstream regulators included lipopolysaccharide, tumor necrosis factor, and a toll-like receptor. Unique to engrafting mice, however, were enrichment for a down-regulated canonical pathway related to B-cell development. Results from this analysis have identified canonical pathways and upstream regulators of BM engraftment in mice and may lead to new approaches to overcome the problem of graft rejection complicating clinical BM transplantation.
2013-01-08 | GSE43310 | GEO
Project description:This dataset allows for the exploration of irradiation and long-term monocyte engraftment on gene expression in wild-type (C57/BL6) mice, across multiple brain regions.
2020-09-08 | GSE157593 | GEO
Project description:<p><strong>BACKGROUND:</strong> The gut-brain axis and the intestinal microbiota are emerging as key players in health and disease. Shifts in intestinal microbiota composition affect a variety of systems, however, evidence of their direct impact on cognitive functions is still lacking. We tested whether faecal microbiota transplant (FMT) from aged donor mice into young adult recipients affected the hippocampus, an area of the central nervous system (CNS) known to be affected by the ageing process, and related functions.</p><p><strong>METHODS AND FINDINGS: </strong>Young adult mice were transplanted with the microbiota from either aged or age-matched donor mice. Following transplantation, characterization of the microbiotas and metabolomics profiles along with a battery of cognitive and behavioural tests were performed. Label-free quantitative proteomics was employed to monitor protein expression in the hippocampus of the recipients. Gut permeability, levels of circulating cytokines and expression of markers of microglia cells were also assessed. FMT from aged donors led to impaired spatial learning and memory in young adult recipients, whereas anxiety, explorative behaviour and locomotor activity remained unaffected. This was paralleled by altered expression of proteins involved in synaptic plasticity and neurotransmission in the hippocampus. Also, a strong reduction of bacteria associated with short-chain fatty acids (SCFAs) production (<em>Lachnospiraceae</em>, <em>Faecalibaculum</em> and <em>Ruminococcaceae</em>) and disorders of the CNS (<em>Prevotellaceae</em> and <em>Ruminococcaceae</em>) was observed. Finally, microglia cells of the hippocampus fimbria, acquired an ageing-like phenotype, while gut permeability and levels of circulating cytokines remained unaffected.</p><p><strong>CONCLUSIONS:</strong> These results demonstrate a direct effect of the age-associated shifts of the microbiota on protein expression and key functions of the central nervous system. Furthermore, these results additionally highlight the paramount importance of the gut-brain axis in ageing and provide a strong rationale to devise therapies aiming to restore a young-like microbiota to improve cognitive functions in the elderly.</p>
2021-12-17 | MTBLS1437 | MetaboLights
Project description:Several viruses can infect the mammalian nervous system and induce neurological dysfunction. Adoptive immunotherapy (AI) is an approach that involves administration of antiviral T cells and has shown promise in clinical studies for the treatment of peripheral virus infections in humans such as cytomegalovirus, Epstein-Barr virus, and adenovirus, among others. Clearance of neurotropic infections, on the other hand, is particularly challenging because the central nervous system (CNS) is relatively intolerant of immunopathological reactions. Therefore, it is essential to develop and mechanistically understand therapies that noncytopathically eradicate pathogens from the CNS. Here, we used mice persistently infected from birth with lymphocytic choriomeningitis virus (LCMV) to demonstrate that therapeutic antiviral T cells can completely purge the persistently infected brain without causing blood brain barrier breakdown or tissue damage. Mechanistically, this is accomplished through a tailored release of chemoattractants that recruit antiviral T cells, but few pathogenic innate immune cells such as neutrophils and inflammatory monocytes. Upon arrival, T cells enlisted the support of nearly all brain resident myeloid cells (microglia) by converting them into CD11c+ antigen-presenting cells (APCs) – a cell population also found in the brain of a human immunodeficiency virus infected patient. Two-photon imaging studies revealed that antiviral CD8+ and CD4+ T cells interacted directly with CD11c+ microglia and induced STAT1 signaling, but did not initiate programmed cell death. We propose that noncytopathic CNS viral clearance can be achieved by therapeutic antiviral T cells reliant on restricted chemoattractant production and interactions with apoptosis-resistant microglia. 6 Mouse Microglia-sorted Brain Samples: 3 (-) AI, 3 (+) AI.
2015-06-22 | E-GEOD-66421 | biostudies-arrayexpress