Genome-wide expression analysis of Dap12 (Tyrobp)-deficient mouse brain and microglial cells
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE9083 | GEO | 2011/08/24
SECONDARY ACCESSION(S): PRJNA102607
REPOSITORIES: GEO
Similar Datasets
Project description:This SuperSeries is composed of the following subset Series: GSE9043: Dap12 microglia GSE9061: Dap12-deficient mouse brain (1 month) Keywords: SuperSeries Refer to individual Series
2011-08-23 | E-GEOD-9083 | biostudies-arrayexpress
Project description:Several proteins are expressed in both immune and nervous systems. However, their putative nonimmune functions in the brain remain poorly understood. KARAP/DAP12 is a transmembrane polypeptide associated with cell-surface receptors in hematopoeitic cells. Its mutation in humans induces Nasu-Hakola disease, characterized by presenile dementia and demyelinization. However, alteration of white matter occurs months after the onset of neuropsychiatric symptoms, suggesting that other neuronal alterations occur in the early phases of the disease. We hypothesized that KARAP/DAP12 may impact synaptic function. In mice deficient for KARAP/DAP12 function, long-term potentiation was enhanced and was partly NMDA receptor (NMDAR) independent. This effect was accompanied by changes in synaptic glutamate receptor content, as detected by the increased rectification of AMPA receptor EPSCs and increased sensitivity of NMDAR EPSCs to ifenprodil. Biochemical analysis of synaptic proteins confirmed these electrophysiological data. In mutants, the AMPA receptor GluR2 subunit expression was decreased only in the postsynaptic densities but not in the whole membrane fraction, demonstrating specific impairment of synaptic receptor accumulation. Alteration of the BNDF-tyrosine kinase receptor B (TrkB) signaling in the mutant was demonstrated by the dramatic decrease of synaptic TrkB with no change in other regulatory or scaffolding proteins. Finally, KARAP/DAP12 was detected only in microglia but not in neurons, astrocytes, or oligodendrocytes. KARAP/DAP12 may thus alter microglial physiology and subsequently synaptic function and plasticity through a novel microglia-neuron interaction.
| S-EPMC6730361 | biostudies-literature
Project description:Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL) is an inherited brain and bone disease. It manifests as dementia and bone fractures. The PLOSL phenotype is caused by loss-of-function mutations in one of the two genes encoding the components of the DAP12/TREM2 receptor complex. The DAP12/TREM2 complex is expressed in cells of the myeloid lineage, including microglia in the central nervous system (CNS). The molecular mechanisms producing the CNS phenotype of PLOSL remain largely unknown. To gain insight into dysfunctional CNS pathways behind PLOSL, we performed genome-wide expression analysis of Dap12 (Tyrobp)-deficient mouse brain. In Dap12-deficient mice, we observed alterations in several pathways involved in synaptic function. In agreement with the myelin loss in PLOSL patients, we also saw changes in transcript levels of genes encoding myelin components. Keywords: knockout response
2011-08-24 | GSE9061 | GEO
Project description:Polycystic lipomembranous osteodysplasia with sclerosing leukoencephalopathy (PLOSL) is an inherited brain and bone disease. It manifests as dementia and bone fractures. The PLOSL phenotype is caused by loss-of-function mutations in one of the two genes encoding the components of the DAP12/TREM2 receptor complex. The DAP12/TREM2 complex is expressed in cells of the myeloid lineage, including microglia in the central nervous system (CNS). The molecular mechanisms producing the CNS phenotype of PLOSL remain largely unknown. To gain insight into dysfunctional CNS pathways behind PLOSL, we performed genome-wide expression analysis of Dap12 (Tyrobp)-deficient mouse brain. In Dap12-deficient mice, we observed alterations in several pathways involved in synaptic function. In agreement with the myelin loss in PLOSL patients, we also saw changes in transcript levels of genes encoding myelin components. Keywords: knockout response Transcript profiles of the midbrain (diencephalon and basal ganglia) of three Dap12-knockout and three heterozygous mice were analyzed.
2011-08-23 | E-GEOD-9061 | biostudies-arrayexpress
Project description:IntroductionHuntington's disease (HD) is a fatal neurodegenerative disorder caused by an expansion of the CAG trinucleotide repeat in the Huntingtin gene (HTT). Immune activation is abundant in the striatum of HD patients. Detection of active microglia at presymptomatic stages suggests that microgliosis is a key early driver of neuronal dysfunction and degeneration. Recent studies showed that deletion of Tyrobp, a microglial protein, ameliorates neuronal dysfunction in Alzheimer's disease amyloidopathy and tauopathy mouse models while decreasing components of the complement subnetwork.ObjectiveWhile TYROBP/DAP12-mediated microglial activation is detrimental for some diseases such as peripheral nerve injury, it is beneficial for other diseases. We sought to determine whether the TYROBP network is implicated in HD and whether Tyrobp deletion impacts HD striatal function and transcriptomics.MethodsTo test the hypothesis that Tyrobp deficiency would be beneficial in an HD model, we placed the Q175 HD mouse model on a Tyrobp-null background. We characterized these mice with a combination of behavioral testing, immunohistochemistry, transcriptomic and proteomic profiling. Further, we evaluated the gene signature in isolated Q175 striatal microglia, with and without Tyrobp.ResultsComprehensive analysis of publicly available human HD transcriptomic data revealed that the TYROBP network is overactivated in the HD putamen. The Q175 mice showed morphologic microglial activation, reduced levels of post-synaptic density-95 protein and motor deficits at 6 and 9 months of age, all of which were ameliorated on the Tyrobp-null background. Gene expression analysis revealed that lack of Tyrobp in the Q175 model does not prevent the decrease in the expression of striatal neuronal genes but reduces pro-inflammatory pathways that are specifically active in HD human brain, including genes identified as detrimental in neurodegenerative diseases, e.g. C1q and members of the Ccr5 signaling pathway. Integration of transcriptomic and proteomic data revealed that astrogliosis and complement system pathway were reduced after Tyrobp deletion, which was further validated by immunofluorescence analysis.ConclusionsOur data provide molecular and functional support demonstrating that Tyrobp deletion prevents many of the abnormalities in the HD Q175 mouse model, suggesting that the Tyrobp pathway is a potential therapeutic candidate for Huntington's disease.
| S-EPMC10924371 | biostudies-literature
Project description:DAP12 is a transmembrane protein, expressed as a disulfide-bonded homodimer and bears an immunoreceptor tyrosine-based activation motif (ITAM). DAP12 is broadly expressed in hematopoietic cells and associates with a variety of cell surface receptors in lymphoid and myeloid cells. Macrophages express several DAP12-associated receptors including triggering receptors expressed by myeloid cells (TREM)-1,2 and 3, myeloid DAP12-associating lectin (MDL)-1, CD200R like proteins CD200R3/R4 and CD300C/D/E . Keywords: Cell type comparison
2008-10-10 | GSE13140 | GEO
Project description:Despite evidence that DAP12 regulates osteoclasts, mice lacking the ITAM-bearing protein exhibit only mild osteopetrosis. Alternatively, Dap12(-/-) mice, also lacking FcRgamma, are severely osteopetrotic, suggesting that FcRgamma compensates for DAP12 deficiency in the bone-resorbing polykaryons. Controversy exists, however, as to whether these co-stimulatory molecules regulate differentiation of osteoclasts or the capacity of the mature cell to degrade bone. We find that Dap12(-/-) osteoclasts differentiate normally when generated on osteoblasts but have a dysfunctional cytoskeleton, impairing their ability to transmigrate through the osteoblast layer and resorb bone. To determine whether the FcRgamma co-receptor, OSCAR mediates osteoclast function in the absence of DAP12, we overexpressed OSCAR fused to FLAG (OSCAR-FLAG), in Dap12(-/-) osteoclasts. OSCAR-FLAG partially rescues the abnormal cytoskeleton of Dap12(-/-) osteoclasts grown on bone, but not those grown on osteoblasts. Thus, cytoskeletal dysfunction, and not arrested differentiation, is the dominant consequence of DAP12 deficiency in osteoclasts. The failure of osteoblasts to normalize Dap12(-/-) osteoclasts indicates that functionally relevant quantities of OSCAR ligand do not reside in bone-forming cells.
| S-EPMC2923570 | biostudies-literature
Project description:IntroductionMicroglial TYROBP (DAP12) is a network hub and driver in sporadic late-onset Alzheimer's disease (AD). TYROBP is a cytoplasmic adaptor for TREM2 and other receptors, but little is known about its roles and actions in AD. Herein, we demonstrate that endogenous Tyrobp transcription is specifically increased in recruited microglia.MethodsUsing a novel transgenic mouse overexpressing TYROBP in microglia, we observed a decrease of the amyloid burden and an increase of TAU phosphorylation stoichiometry when crossed with APP/PSEN1 or MAPTP301S mice, respectively. Characterization of these mice revealed Tyrobp-related modulation of apolipoprotein E (Apoe) transcription. We also showed that Tyrobp and Apoe mRNAs were increased in Trem2-null microglia recruited around either amyloid beta deposits or a cortical stab injury. Conversely, microglial Apoe transcription was dramatically diminished when Tyrobp was absent.ConclusionsOur results provide evidence that TYROBP-APOE signaling does not require TREM2 and could be an initiating step in establishment of the disease-associated microglia (DAM) phenotype.
| S-EPMC7938663 | biostudies-literature
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2014-10-10 | E-GEOD-35707 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the SubSeries listed below. Refer to individual Series
2016-06-29 | E-GEOD-71874 | biostudies-arrayexpress