Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

ADGRB1 contributes to astrocyte-mediated phagocytosis of excitatory synapses

ABSTRACT: The phagocytic activity of astrocytes plays an important role in synapse refinement through the elimination of excess synapses during brain development. The adhesion G protein-coupled receptor BAI1/ADGRB1 contributes to phagocytosis in various tissues, including the clearance of apoptotic myoblasts in skeletal muscle and epithelial cells in the intestine. However, the phagocytic function of ADGRB1 in the brain has not been thoroughly investigated. Given that Adgrb1 is highly expressed in astrocytes but not in microglia, we examined changes in astrocyte gene expression resulting from the loss of ADGRB1. RNA-seq analysis revealed that astrocytes lacking ADGRB1 exhibit altered expression of genes associated with cytoskeleton organization and chemotaxis, processes that are required for phagocytosis. Using cultured astrocytes from mice lacking full-length ADGRB1 (Adgrb1exon2-/-) and wildtype (WT) littermates, we found that Adgrb1exon2-/- astrocytes exhibit significantly reduced phagocytic capacity when compared to similarly prepared astrocytes from WT littermates. Immunostaining of astrocytes and pre-synaptic markers showed less engulfed pre-synaptic elements in astrocytes from Adgrb1exon2-/- mutants. Finally, immunostaining of pre-synaptic and post synaptic markers revealed a significantly higher density of excitatory synapses in Adgrb1exon2-/- mutants. These findings highlight the importance of ADGRB1 in synaptic remodeling and raise the possibility that reduced astrocyte-mediated phagocytosis might underlie the behavioral alterations previously observed in Adgrb1exon2-/- mutants, including increased seizure susceptibility and deficits in social memory.

ORGANISM(S): Mus musculus

PROVIDER: GSE255050 | GEO | 2024/03/19

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Functional astrocytes differentiated from hiPSCs

Project description:Growing evidence implicates the importance of glia, particularly astrocytes, in neurological and psychiatric diseases. Here, we describe a rapid and robust method for the differentiation of highly pure populations of astrocytes from human induced pluripotent stem cells (hiPSCs), via a neural progenitor cell (NPC) intermediate. Using this method, we generated hiPSC-derived astrocyte populations (hiPSC-astrocytes) from 42 NPC lines (derived from 30 individuals) with an average of ~90% S100β-positive cells. Transcriptomic analysis demonstrated that the hiPSC-astrocytes are highly similar to primary human fetal astrocytes and characteristic of a non-reactive state. hiPSC-astrocytes respond to inflammatory stimulants, display phagocytic capacity and enhance microglial phagocytosis. hiPSC-astrocytes also possess spontaneous calcium transient activity. Our novel protocol is a reproducible, straightforward (single media) and rapid (<30 days) method to generate homogenous populations of hiPSC-astrocytes that can be used for neuron-astrocyte and microglia-astrocyte co-cultures for the study of neuropsychiatric disorders.

2017-08-18 | GSE97904 | GEO

Acutely isolated murine cortical astrocytes and microglia: Alzheimer's disease vs wildtype

Project description:Isolation of glia from Alzheimer's mice reveals inflammation andÂ dysfunction. Reactive astrocytes and microglia are associated with amyloid plaques in Alzheimer's disease (AD). Yet, not much is known about the molecular alterations underlying this reactive phenotype. To get an insight into the molecular changes underlying AD induced astrocyte and microglia reactivity, we performed a transcriptional analysis on acutely isolated astrocytes and microglia from the cortex of aged controls and APPswe/PS1dE9 AD mice. As expected, both cell types acquired a proinflammatory phenotype, which confirms the validity of our approach. Interestingly, we observed that the immune alteration in astrocytes was relatively more pronounced than in microglia. Concurrently, our data reveal that astrocytes display a reduced expression of neuronal support genes and genes involved in neuronal communication. The microglia showed a reduced expression of phagocytosis and/or endocytosis genes. Co-expression analysis of a human AD expression data set and the astrocyte and microglia data sets revealed that the inflammatory changes in astrocytes were remarkably comparable in mouse and human AD, whereas the microglia changes showed less similarity. Based on these findings we argue that chronically proinflammatory astrocyte and microglia phenotypes, showing a reduction of genes involved in neuronal support and neuronal signaling, are likely to contribute to the neuronal dysfunction and cognitive decline in AD. 2 cell types from 2 conditions: cortical microglia and cortical astrocytes from 15-18 month old APPswe/PS1dE9 mice compared to wildtype littermates. Biological replicates: microglia from APPswe/PS1dE9, N=7, microglia from WT, N=7, astrocytes from APPswe/PS1dE9, N=4, microglia from WT, N=4

2015-11-04 | E-GEOD-74615 | biostudies-arrayexpress

ADGRB1 contributes to astrocyte-mediated phagocytosis of excitatory synapses

Project description:ADGRB1 contributes to astrocyte-mediated phagocytosis of excitatory synapses

| PRJNA1073438 | ENA

Neuronal integrity, not activity, drives synaptic material clearance by microglia after CNS injury

Project description:Phagocytosis of synaptic debris by microglia is critical for CNS development and homeostasis. Less well understood are microglial functions in injured adult brain, where their presumed role is clearance of neuronal debris. Assay of this process is challenging, because the resulting peripheral myeloid-cell engraftment is difficult to dissociate from microglial clearance. The model used here, optic nerve crush injury in adult mouse, stimulates rapid engulfment of synaptic material by microglia residing in the lateral geniculate nucleus (LGN), sufficiently distant from the injury to preclude peripheral-cell engraftment. Pre-injury pharmacological depletion of microglia causes post-injury accumulation of synaptic debris, suggesting that these, not astrocytes, are the dominant post-injury phagocytes. Genetic and pharmacological manipulations revealed that neuronal activity, which regulates microglial engulfment of synaptic debris in development, does not do so in post-injury synaptic material clearance in adulthood, where such clearance depends instead on axonal integrity. RNAseq reveals C1q involvement in clearance of debris by LGN-resident microglia, supporting our finding of its impaired clearance in C1qa-/- and Itgam-/- mice. Our results demonstrate how neurodegenerative debris is cleared by microglial phagocytosis, and offer a model for assaying microglial phagocytic activity and studying its mechanisms and physiological roles.

2018-06-07 | GSE107635 | GEO

Proteomic analysis of gliosomes from mouse brain for investigation of glial membrane proteins

Project description:Astrocytes are increasingly recognized as crucial contributors to neuronal function at synapses, axons, and somas. Reliable methods that can provide insight into the astrocyte proteins at the neuron-astrocyte functional interface are highly desirable. Here we conducted a mass spectrometry analysis of Percoll® gradient isolated gliosomes, a viable preparation of glial subcellular particles often used to study mechanisms of astrocytic transmitter uptake and release and their regulation. Gliosomes were compared with synaptosomes, a preparation containing the neurotransmitter release machinery, and accordingly synaptosomes were enriched for proteins involved in synaptic vesicle mediated transport. Interestingly, gliosome preparations were found to be enriched for different classes of known astrocyte proteins, such as VAMP3 (involved in astrocyte exocytosis), Ezrin (perisynaptic astrocyte cytoskeletal protein), and Basigin (astrocyte membrane glycoprotein), as well as for G-protein mediated signaling proteins. Together, these data provide the first detailed description of the gliosome proteome and show that gliosomes can be a useful preparation to study glial membrane proteins and associated processes.

2014-11-17 | PXD001375 | Pride

Astrocyte-encoded positional cues maintain sensorimotor circuit integrity

Project description:Astrocytes, the most abundant cells in the central nervous system, promote synapse formation and help refine neural connectivity. Although they are allocated to spatially distinct regional domains during development, it is unknown whether region-restricted astrocytes are functionally heterogeneous. Here we show that postnatal spinal cord astrocytes express several region-specific genes, and that ventral astrocyte-encoded Semaphorin3a (Sema3a) is required for proper motor neuron and sensory neuron circuit organization. Loss of astrocyte-encoded Sema3a led to dysregulated α−motor neuron axon initial segment orientation, markedly abnormal synaptic inputs, and selective death of α−but not of adjacent γ−motor neurons. Additionally, a subset of TrkA+ sensory afferents projected to ectopic ventral positions. These findings demonstrate that stable maintenance of a positional cue by developing astrocytes influences multiple aspects of sensorimotor circuit formation. More generally, they suggest that regional astrocyte heterogeneity may help to coordinate postnatal neural circuit refinement. 12 total samples consisting of three biological replicates each of flow sorted postnatal day 7 dorsal spinal cord astrocytes, ventral spinal cord astrocytes, dorsal SC non astrocytes, and ventral SC non astrocytes

2014-05-02 | E-GEOD-55054 | biostudies-arrayexpress

Extracellular matrix remodeling enhancing astrocyte lysosome pathway to reverse memory defected in Alzheimer’s disease

Project description:Extracellular matrix (ECM) remodeling is strongly linked to Alzheimer’s disease (AD) risk, but its functions are not fully understood. Here, we found that medial prefrontal cortex (mPFC) injection with chondroitinase ABC (ChABC) to remodel ECM reverses short-term memory loss and reduces Aβ deposition in 5xFAD mice. ECM remodeling also reactivates astrocytes, untangles aggrecan’s entanglement with amyloid-beta (Aβ) plaques, and encourages astrocyte recruitment to the surrounding plaques. ECM remodeling promotes astrocyte phagocytosis of Aβ plaque by activating the astrocyte phagocytosis receptor mertk and astrocytic vesicle circulation. Importantly, ECM remodeling enhances the autophagy-lysosome pathway in astrocytes to mediate Aβ clearance and alleviate AD pathology. Our work thus discovers a cellular mechanism to remodel the ECM to active astrocyte autophagic lysosomal pathway alleviation AD pathology. It may represent a potential therapeutic strategy and serve as a hallmark for treating AD.

2024-10-17 | PXD046784 | Pride

Astrocyte-secreted IL-33 mediates homeostatic synaptic plasticity in the adult hippocampus

Project description:Hippocampal synaptic plasticity is important for learning and memory formation. Homeostatic synaptic plasticity is a specific form of synaptic plasticity that is induced upon prolonged changes in neuronal activity to maintain network homeostasis. While astrocytes are important regulators of synaptic transmission and plasticity, it is largely unclear how they interact with neurons to regulate synaptic plasticity at the circuit level. Here, we show that neuronal activity blockade selectively increases the expression and secretion of IL-33 (interleukin-33) by astrocytes in the hippocampal cornu ammonis 1 (CA1) subregion. This IL-33 stimulates an increase in excitatory synapses and neurotransmission through the activation of neuronal IL-33 receptor complex and synaptic recruitment of the scaffold protein PSD-95. We found that acute administration of tetrodotoxin in hippocampal slices or inhibition of hippocampal CA1 excitatory neurons by optogenetic manipulation increases IL-33 expression in CA1 astrocytes. Furthermore, IL-33 administration in vivo promotes the formation of functional excitatory synapses in hippocampal CA1 neurons, whereas conditional knockout of IL-33 in CA1 astrocytes decreases the number of excitatory synapses therein. Importantly, blockade of IL-33 and its receptor signaling in vivo by intracerebroventricular administration of its decoy receptor inhibits homeostatic synaptic plasticity in CA1 pyramidal neurons and impairs spatial memory formation in mice. These results collectively reveal an important role of astrocytic IL-33 in mediating the negative-feedback signaling mechanism in homeostatic synaptic plasticity, providing insights into how astrocytes maintain hippocampal network homeostasis.

2020-12-14 | GSE161540 | GEO

Complement C1q-dependent synapse elimination by astrocytes in a mouse model of Alzheimer's disease

Project description:Synapse loss and glial activation are hallmarks of Alzheimer's disease (AD). In Tau P301S transgenic mice, the complement pathway contributes to neuronal damage through microglial elimination of synapses. Here, we used unbiased proteomic profiling of postsynaptic density (PSD) fractions from Tau P301S mice in C1q-WT versus C1q knockout backgrounds to identify C1q-dependent changes at synapses. Integrative multi-omics analysis revealed that astrocyte- and microglia- specific proteins are increased in Tau P301S synapse fractions with age and in a C1q-dependent manner. The same set of glial proteins (including C1q, C4, Gpnmb, and S100a4) is elevated in human AD synaptic fractions, and C4 levels are raised in cerebrospinal fluid (CSF) from AD patients. Besides microglia, we show that astrocytes contribute substantially to excitatory and inhibitory synapse engulfment in Tau P301S hippocampus. Based on staining of synapse markers within lysosomes, astrocytes showed preference for excitatory synapses whereas microglia preferred to engulf inhibitory synapse markers. Genetic deletion of C1q reduced astrocytic eating of excitatory and inhibitory synapses in Tau P301S mice, and rescued synapse density. Together, our data indicate that astrocytes contact and phagocytose synapses in a C1q- dependent manner and thereby contribute to synapse loss and neurodegeneration in AD.

2021-11-03 | MSV000088313 | MassIVE

Astrocyte-enriched pan-brain aging transcriptome

Project description:Normal brain aging is marked by a cognitive decline, spurred by changes in cellular metabolism and homeostatic dysregulation, as well as modifications in synapses and neuronal connectivity. Astrocytes are well positioned as an effector of these changes, although how properties of astrocytes change with age remains unclear. Here, we address this question by profiling astrocytic gene expression from multiple brain regions of adult (4 month-old) and aged (2 years-old) mice. We isolated mRNA from transgenic mice where ribosomes within astrocytes were genetically tagged (GFAP-cre x RPL22-HA, astrocyte ribotag). We then used RNA sequencing to identify and quantify the astrocyte-enriched mRNA, analyzing 4 different brain regions: visual cortex, somatomotor cortex, hypothalamus, and cerebellum. Overall, we find that astrocyte expression of inflammatory and immune response factors increase with age, as well as changes in genes associated with metabolism, cholesterol synthesis, and synaptogenesis. Going forward, these data contribute to an understanding of astrocyte diversity and provide insight into the role of astrocytes in normal aging.

2017-12-11 | GSE99791 | GEO

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data