Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Microglia contribute to polyG-dependent neurodegeneration in neuronal intranuclear inclusion disease II

ABSTRACT: Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disease caused by GGC repeat expansion of NOTCH2NLC. Despite the identification of uN2CpolyG, a toxic polyglycine (polyG) protein, the pathogenic mechanisms of NIID remain unclear. Herein, we investigated the role of polyG by expressing wild-type NOTCH2NLC, expanded NOTCH2NLC with 100 GGC repeats (translating or not translating into uN2CpolyG), or mutated NOTCH2NLC that encodes a pure polyG without GGC-repeat RNA and C-terminal stretch (uN2CpolyG-dCT) in mice. Both uN2CpolyG and uN2CpolyG-dCT induced the formation of inclusions composed by filamentous materials and caused neurodegenerative phenotypes in mice, including impaired motor and cognitive performance, shortened lifespan, and pathological lesions such as white matter lesions, microgliosis, and astrogliosis. By contrast, the sole expression of GGC-repeat RNA was non-pathogenic. Combining with bulk and single-nuclei RNA-seq, we determined the common molecular signatures associated with expressing uN2CpolyG and uN2CpolyG-dCT in the brain, especially the up-regulation of inflammation and microglia markers whereas down-regulation of immediate early genes and splicing factors. Importantly, microglia-mediated inflammation was visualized in NIID patients by positron emission tomography, which correlated with white matter atrophy levels. Moreover, microglia ablation ameliorated neurodegeneration in uN2CpolyG-expressing mice but did not alter polyG inclusions. Together, these results demonstrate that polyG is critical for the pathogenesis of NIID, and microglia contribute to polyG-induced neurodegeneration.

ORGANISM(S): Mus musculus

PROVIDER: GSE269183 | GEO | 2024/07/04

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Similar Datasets

Microglia contribute to polyG-dependent neurodegeneration in neuronal intranuclear inclusion disease

Project description:Neuronal intranuclear inclusion disease (NIID) is a neurodegenerative disease caused by GGC repeat expansion of NOTCH2NLC. Despite the identification of uN2CpolyG, a toxic polyglycine (polyG) protein, the pathogenic mechanisms of NIID remain unclear. Herein, we investigated the role of polyG by expressing wild-type NOTCH2NLC, expanded NOTCH2NLC with 100 GGC repeats (translating or not translating into uN2CpolyG), or mutated NOTCH2NLC that encodes a pure polyG without GGC-repeat RNA and C-terminal stretch (uN2CpolyG-dCT) in mice. Both uN2CpolyG and uN2CpolyG-dCT induced the formation of inclusions composed by filamentous materials and caused neurodegenerative phenotypes in mice, including impaired motor and cognitive performance, shortened lifespan, and pathological lesions such as white matter lesions, microgliosis, and astrogliosis. By contrast, the sole expression of GGC-repeat RNA was non-pathogenic. Combining with bulk and single-nuclei RNA-seq, we determined the common molecular signatures associated with expressing uN2CpolyG and uN2CpolyG-dCT in the brain, especially the up-regulation of inflammation and microglia markers whereas down-regulation of immediate early genes and splicing factors. Importantly, microglia-mediated inflammation was visualized in NIID patients by positron emission tomography, which correlated with white matter atrophy levels. Moreover, microglia ablation ameliorated neurodegeneration in uN2CpolyG-expressing mice but did not alter polyG inclusions. Together, these results demonstrate that polyG is critical for the pathogenesis of NIID, and microglia contribute to polyG-induced neurodegeneration.

2024-07-04 | GSE268950 | GEO

Expression of expanded GGC repeats within NOTCH2NLC causes cardiac dysfunction in mouse models

Project description:Background: Neuronal intranuclear inclusion disease (NIID) is a rare neurodegenerative disorder characterized by widespread intranuclear inclusions in the nervous system as well as multiple visceral organs. In 2019, expanded GGC repeats within the 5’ untranslated region of the NOTCH2NLC gene was identified as the causative factor. Although NIID primarily affects the central and peripheral nervous systems, growing evidence suggests potential cardiac abnormalities in NIID. However, the link between expanded GGC repeats within NOTCH2NLC and cardiac dysfunction remains uncertain. Results: In this study, we utilized two transgenic mouse models, expressing NOTCH2NLC-(GGC)98 ubiquitously or specifically in cardiomyocytes, and identified p62-positive intranuclear NOTCH2NLC-polyG inclusions in cardiomyocytes in two mouse models. We observed that both models exhibited cardiac-related pathological and echocardiographic changes, albeit exhibiting varying degrees of severity. Transcriptomic analysis revealed shared downregulation of genes related to ion channels and mitochondria in both models, with the cardiomyocyte-specific mice showing a more pronounced downregulation of mitochondria and energy metabolism-related pathways. Further investigations revealed decreased expression of mitochondria-related genes and electron transport chain activity. At last, we conducted a retrospective review of cardiac-related examination results from NIID patients at our hospital and also identified some cardiac abnormalities in NIID patients. Conclusions: Our study provided the first in vivo evidence linking GGC repeat expansions within NOTCH2NLC to cardiac abnormalities and highlighted the contribution of mitochondrial dysfunction in the development of cardiac abnormalities.

2023-08-30 | GSE241464 | GEO

GGC repeat expansion within NOTCH2NLC causes behavioral deficits and neurodegeneration through misregulated alternative splicing

Project description:GGC repeat expansion within NOTCH2NLC gene has been identified as the genetic cause of neuronal intranuclear inclusion disease (NIID). To understand the molecular pathogenesis of NIID, here we have established both a transgenic mouse model and a human neural progenitor cell (hNPC) model. We show that the expression of the NOTCH2NLC gene with expanded GGC repeats produces multiple forms of polypeptides, including polyglycine (polyG), polyalanine (polyA) and polyarginine (polyR), and leads to widespread intranuclear inclusions, severe neurodegeneration, motor dysfunction and cognitive deficits, which faithfully mimics the clinical manifestations and pathological features associated with NIID. We further performed RNA-seq on the prefrontal cortex, cerebellum and hippocampus of the transgenic mice and on the hNPC model and identified a large proportion of conserved alternative splicing between the NIID mouse and hNPC cell models. Analyses of the conserved alternative splicing revealed the enrichment of the binding motif of hnRNPM. We found that hnRNPM could interact with and be sequestered by expanded NOTCH2NLC-polyG and -polyA. Functional expression of hnRNPM could ameliorate the cellular toxicity caused by expanded GGC repeats within NOTCH2NLC. These results together suggest that dysregulated alternative splicing could play a vital role in the molecular pathogenesis of NIID.

2023-01-04 | GSE182878 | GEO

Deciphering glial contributions to CSF1R-related leukoencephalopathy via single-nuclear transcriptomic profiling: A case study

Project description:Adult-onset leukoencephalopathy with axonal spheroids and pigmented glia (ALSP) is a neurodegenerative disorder resulting from genetic alterations in CSF1R, a gene expressed by microglia. We studied an elderly man with a hereditary progressive dementing and behavioral disorder of unclear etiology. Standard genetic testing for leukodystrophy and other neurodegenerative conditions was negative. Brain autopsy revealed classic features of ALSP, including confluent white matter degeneration with axonal spheroids and pigmented glial cells in the affected white matter. Subsequent long-read sequencing identified a novel deletion in CSF1R. To elucidate mechanisms underlying white matter degeneration in ALSP, we compared multiple brain regions exhibiting varying degrees of white matter pathology. Our analysis revealed markedly decreased CSF1R transcript levels and protein across brain regions, including intact white matter. Single nuclear RNA sequencing (snRNAseq) analysis identified two disease-associated microglial cell states: lipid-laden microglia (expressing GPNMB, ATG7, LGALS1, LGALS3) and inflammatory microglia (expressing IL2RA, ATP2C1, FCGBP, VSIR, SESN3), along with a small population of CD44+ peripheral monocyte-derived macrophages exhibiting migratory and phagocytic signatures. Disease-associated oligodendrocytes exhibited cell stress signatures and dysregulated apoptosis-related genes. Disease-associated oligodendrocyte precursor cells (OPCs) displayed a failure in their differentiation into mature myelin-forming oligodendrocytes, as evidenced by upregulated LRP1, PDGFRA, SOX5, NFIA, and downregulated NKX2-2, NKX6.2, SOX4, SOX8, TCF7L2, YY1, ZNF488. Overall, our findings highlight microglia–oligodendroglia crosstalk in demyelination, with CSF1R dysfunction promoting phagocytic and inflammatory microglia states, resulting in oligodendrocyte depletion, an arrest in OPC differentiation, and lack of remyelination.

2024-08-29 | GSE267301 | GEO

SIRT1 deficiency in microglia contributes to cognitive decline in aging and neurodegeneration via epigenetic regulation of IL-1beta

Project description:Aging is the predominant risk factor for neurodegenerative diseases. One key phenotype as brain ages is the aberrant innate immune response characterized by proinflammation. However, the molecular mechanisms underlying aging-associated proinflammation are poorly defined. Whether chronic inflammation plays a causal role in cognitive decline in aging and neurodegeneration has not been established. Here we established a mechanistic link between chronic inflammation and aging microglia, and demonstrated a causal role of aging microglia in neurodegenerative cognitive deficits. Expression of microglial SIRT1 reduces with the aging of microglia. Genetic reduction of microglial SIRT1 elevates IL-1Î² selectively, and exacerbates cognitive deficits in aging and in transgenic mouse models of frontotemporal dementia (FTD). Interestingly, the selective activation of IL-1Î² transcription by SIRT1 deficiency is likely mediated through hypomethylating the proximal promoter of IL-1Î². Consistent with our findings in mice, selective hypomethylation of IL-1Î² at two CpG sites are found in normal aging humans and demented patients with tauopathy. Our findings reveal a novel epigenetic mechanism in aging microglia that contributes to cognitive deficits in neurodegenerative diseases. Study of changes related to alterations of SIRT1 levels in microglia of young and aged animals and in models of neurodegenerative dementia

2014-10-01 | E-GEOD-56452 | biostudies-arrayexpress

C9orf72 deficiency promotes microglial mediated synaptic loss in aging and amyloid accumulation [bulk RNA-seq]

Project description:C9orf72 repeat expansions cause inherited amyotrophic lateral sclerosis/frontotemporal dementia (ALS/FTD) and result in both loss of C9orf72 protein expression and production of potentially toxic RNA and dipeptide repeat proteins. In addition to ALS/FTD, C9orf72 repeat expansions have been reported in a broad array of neurodegenerative syndromes including Alzheimer’s disease. Here we show that C9orf72 deficiency promotes loss of homeostatic signatures in microglia and transition to an inflammatory state characterized by an enhanced type I IFN signature. Furthermore, C9orf72-depleted microglia trigger age-dependent neuronal defects, in particular enhanced cortical synaptic pruning, leading to altered learning and memory behaviors in mice. Interestingly, C9orf72 deficient microglia also promote enhanced synapse loss and neuronal deficits in a mouse model of amyloid accumulation, while paradoxically improving plaque clearance. These findings suggest that altered microglial function due to decreased C9orf72 expression directly contributes to neurodegeneration in repeat expansion carriers independent of gain of function toxicities.

2022-06-15 | GSE164675 | GEO

C9orf72 deficiency promotes microglial mediated synaptic loss in aging and amyloid accumulation [scRNA-seq]

2022-06-15 | GSE164674 | GEO

Neurodegeneration and Neuroinflammation are Linked, but Independent of α-Synuclein Inclusions, in a Seeding/Spreading Mouse Model of Parkinson’s Disease

Project description:A key process of neurodegeneration in Parkinson's disease (PD) is the transneuronal spreading of alpha-synuclein. Alpha-synuclein is a presynaptic protein that is implicated in the pathogenesis of PD and other synucleinopathies, where it forms, upon intracellular aggregation, pathological inclusions. Other hallmarks of PD include neurodegeneration and microgliosis in susceptible brain regions. Whether it is primarily transneuronal spreading of a-synuclein particles, inclusion formation, or other mechanisms, such as inflammation, that cause neurodegeneration in PD is unclear. We used spreading/aggregation of alpha-synuclein induced by intracerebral injection of a-synuclein preformed fibrils into the mouse brain to address this question. We performed quantitative histological analysis for a-synuclein inclusions, neurodegeneration, and microgliosis in different brain regions, and a gene expression profiling of the ventral midbrain, at two different timepoints after disease induction. We observed significant neurodegeneration and microgliosis in brain regions not only with, but also withouta-synuclein inclusions. We also observed prominent microgliosis in injured brain regions that did not correlate with neurodegeneration nor with inclusion load. In longitudinal gene expression profiling experiments, we observed early and unique alterations linked to microglial mediated inflammation that preceded neurodegeneration, indicating an active role of microglia in inducing neurodegeneration. Our observations indicate that a-synuclein inclusion formation is not the major driver in the early phases of PD-like neurodegeneration, but that diffusible, oligomeric a-synuclein species, which induce unusual microglial reactivity, play a key role in this process.

2020-11-02 | GSE155716 | GEO

Mutant Huntingtin promotes neuronal death through cell autonomous microglial activation via myeloid lineage- determining factors

Project description:Huntington's Disease (HD) is a fatal neurodegenerative disorder caused by an extended polyglutamine repeat in the N-terminus of the huntingtin (Htt) protein. Reactive microglia and elevated cytokine levels are observed in the brains of HD patients, but the extent to which neuroinflammation results from extrinsic or cell-autonomous mechanisms is unknown. Furthermore, the impact of microglia activation on the pathogenesis of HD remains to be established. Using genome-wide approaches, we show that expression of mutant Htt in microglia promotes cell-autonomous pro-inflammatory transcriptional activation within microglia by increasing the expression and transcriptional activities of the myeloid lineage-determining factors PU.1 and C/EBPs. Elevated levels of PU.1 and its target genes are observed in the brains of mouse models and HD individuals. Moreover, mutant Htt expressing microglia exhibit an increased capacity to induce neuronal death ex vivo and in vivo in the presence of sterile inflammation. These findings suggest that expression of mutant Htt in microglia may contribute to neuronal pathology in Huntingtin disease. RNA-Seq and ChIP-Seq for PU.1, C/EBP, and H3K4me2 in BV2 cells and RNA-Seq in primary microglia and macrophages

2014-03-02 | E-GEOD-54443 | biostudies-arrayexpress

Defining the microglia transcriptome in multifunctional protein-2 deficient mice

Project description:Purpose: We purified whole brain microglia of MFP2 knockout mice and control mice utilizing percoll gradient and FACS sorting, followed by microarray analysis to define the molecular changes in MFP2 knockout mice at the endstage of the disease. We compared the microglia transcriptome of Mfp2-/- microglia to that of SOD1-G93A microglia isolated from spinal cord to define the microglia signature associated with a non-neurodegenerative environment. Results and conclusions: Mfp2-/- microglia acquire an activation state characterized by activation of mammalian target of rapamycin (mTOR). In addition, activated microglia display reduced expression of genes that are normally highly expressed by surveillant microglia in steady-state conditions. The immunological profile of is heterogeneous and encompasses upregulation of both pro- and anti-inflammatory genes. In contrast to the neurodegeneration-specific microglia profile in SOD1-G93A mice, Mfp2-/- microglia do not induce genes associated with phagocytosis, lysosomal activation and neurotoxicity. 4 MFP2 knockout and 4 control samples were subjected to microarray analysis.

2015-04-14 | E-GEOD-66420 | biostudies-arrayexpress

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

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