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PROVIDER: PRJNA284165 | ENA |
REPOSITORIES: ENA
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Project description:Homeostatic plasticity, a form of synaptic plasticity, maintains the fine balance between overall excitation and inhibition in developing and mature neuronal networks. Although the synaptic mechanisms of homeostatic plasticity are well characterized, the associated transcriptional program remains poorly understood. We show that the Kleefstra syndrome-associated protein, EHMT1, plays a critical and cell-autonomous role in synaptic scaling by responding to attenuated neuronal firing or sensory drive. Chronic activity deprivation increased the amount of neuronal dimethylated H3 at lysine 9 (H3K9me2), the catalytic product of EHMT1 and an epigenetic marker for gene repression. Genetic knockdown and pharmacological blockade of EHMT1 or EHMT2 prevented the increase of H3K9me2 and synaptic scaling up. Furthermore, BDNF repression was preceded by EHMT1/2-mediated H3K9me2 deposition at the Bdnf promoter during synaptic scaling up, both in vivo or in vivo. These findings suggest that changes in chromatin state through H3K9me2 governs a repressive program to achieve synaptic scaling. 12 samples (4 conditions in biological triplicate), 3 wt, 3 wt tetradotoxin treated, 3 k.d., 3 k.d. tetradotoxin treated
2016-06-30 | E-GEOD-68960 | biostudies-arrayexpress
Project description:Homeostatic plasticity, a form of synaptic plasticity, maintains the fine balance between overall excitation and inhibition in developing and mature neuronal networks. Although the synaptic mechanisms of homeostatic plasticity are well characterized, the associated transcriptional program remains poorly understood. We show that the Kleefstra syndrome-associated protein, EHMT1, plays a critical and cell-autonomous role in synaptic scaling by responding to attenuated neuronal firing or sensory drive. Chronic activity deprivation increased the amount of neuronal dimethylated H3 at lysine 9 (H3K9me2), the catalytic product of EHMT1 and an epigenetic marker for gene repression. Genetic knockdown and pharmacological blockade of EHMT1 or EHMT2 prevented the increase of H3K9me2 and synaptic scaling up. Furthermore, BDNF repression was preceded by EHMT1/2-mediated H3K9me2 deposition at the Bdnf promoter during synaptic scaling up, both in vivo or in vivo. These findings suggest that changes in chromatin state through H3K9me2 governs a repressive program to achieve synaptic scaling.
2016-06-30 | GSE68960 | GEO
Project description:Kleefstra syndrome, a disease with intellectual disability, autism spectrum disorders and other developmental defects is caused in humans by haploinsufficiency of EHMT1. Although EHMT1 and its paralog EHMT2 were shown to be histone methyltransferases responsible for deposition of the di-methylated H3K9 (H3K9me2), the exact nature of epigenetic dysfunctions in Kleefstra syndrome remains unknown. Here, we found that the epigenome of Ehmt1+/- adult mouse brain displays a marked increase of H3K9me2/3 which correlates with impaired expression of protocadherins, master regulators of neuronal diversity. Increased H3K9me3 was present already at birth, indicating that aberrant methylation patterns are established during embryogenesis. Interestingly, we found that Ehmt2+/- mice do not present neither the marked increase of H3K9me2/3 nor the cognitive deficits found in Ehmt1+/- mice, indicating an evolutionary diversification of functions. Our finding of increased H3K9me3 in Ehmt1+/- mice is the first one supporting the notion that EHMT1 can quench the deposition of tri-methylation by other Histone methyltransferases, ultimately leading to impaired neurocognitive functioning. Our insights into the epigenetic pathophysiology of Kleefstra syndrome may offer guidance for future developments of therapeutic strategies for this disease.
2018-03-07 | GSE89010 | GEO
Project description:Kleefstra syndrome (KS, also known as 9q.34.3 deletion syndrome) is a rare genetic disorder characterized by a developmental delay, abnormal behaviors and autism-like features. This syndrome is caused by haplo-insufficiency of the euchromatin histone methyltransferase 1 gene (EHMT1/GLP/KDM1D). This gene product, GLP is a methyltransferase responsible for mono- and di-methylation of lysine 9 on histone H3 N-terminal tail, which modulates epigenetic information. Ehmt1 heterozygous mutant (Ehmt1∆/+) mice show KS-like abnormal behavioral phenotypes and utilized as KS model mice. Here, we isolated nuclei from adult Ehmt1∆/+ mice cortex and analysed gene expression precisely by single nucleus RNA-seq analysis. It showed that many genes were up or down regulated in different cell types of Ehmt1∆/+ mice brain. Among them, inflammation associating genes are up-regulated in Ehmt1∆/+ mice neuronal cells. And this up-regulation was reversed by postnatal supply of GLP in post-mitotic neuron of Ehmt1∆/+ mice brain.
2021-06-11 | GSE162934 | GEO
Project description:Haploinsufficiency of the Euchromatin histone methyltransferase 1 (EHMT1) gene leads to Kleefstra Syndrome, a rare disease characterised by moderate to severe developmental delay/intellectual disability, childhood hypotonia and distinct facial features, comprising microcephaly. This study examines the genetic variant EHMT1_Ter (p.[Tyr1148=];[Tyr1148Leufs*9]) in HEK293 cells.
2020-09-04 | GSE157390 | GEO
Project description:EHMT1 haploinsufficiency causes Kleefstra syndrome (KS), a complex disorder of developmental delay and intellectual disability. EHMT1 encodes a lysine methyltransferase GLP and regulates histone H3 lysine 9 dimethylation (H3K9me2). Ehmt1 heterozygous mutant (Ehmt1∆/+) mice show KS-like abnormal behavioral phenotypes. Here, we examined the reversibility of decreased H3K9me2 by postnatal supply of GLP in post-mitotic neuron of Ehmt1∆/+ mice brain. For this purpose, we generated the mice harboring inducible Ehmt1 cDNA with CamKII-creER (Ehmt1 iTG-neuron mice) in Ehmt1∆/+ background. These mice expressed exogenous Ehmt1 in post-mitotic neuron upon Tamoxifen treatment. Using these mice, we sorted out NeuN+ cells from cortical region and performed Histone H3 K9-dimethyation ChIP analysis. Here we showed that Ehmt1 haploinsufficiency induces global reduction of euchromatic H3K9me2 especially in the euchromatic region of brain and that postnatal supply of GLP can reverse the diminished H3K9me2 phenotype, even in a postmitotic situation.
2021-06-09 | GSE162327 | GEO
Project description:Genetic evidence indicates disrupted epigenetic regulation as a major risk factor for psychiatric disorders, but the molecular mechanisms that drive this association are undetermined. EHMT1 is an epigenetic repressor that is causal for Kleefstra Syndrome (KS), a neurodevelopmental disorder (NDD) leading to ID, and is associated with schizophrenia. Here, we show that reduced EHMT1 activity decreases NRSF/REST protein leading to abnormal neuronal gene expression and progression of neurodevelopment in human iPSC. We further show that EHMT1 regulates NRSF/REST indirectly via repression of miRNA leading to aberrant neuronal gene regulation and neurodevelopment timing. Expression of a NRSF/REST mRNA that lacks the miRNA-binding sites restores neuronal gene regulation to EHMT1 deficient cells. Importantly, the EHMT1-regulated miRNA gene set with elevated expression is enriched for NRSF/REST regulators with an association for ID and schizophrenia. This reveals a molecular interaction between H3K9 dimethylation and NSRF/REST contributing to the aetiology of psychiatric disorders.
2023-05-01 | E-MTAB-10480 | biostudies-arrayexpress
Project description:Over 400 million people worldwide are living with a rare disease, with genetic variants determining 80% of cases. Next Generation Sequencing identifies potential disease causative genetic variants, however many of these are classified as variants of uncertain significance (VUS). Each VUS requires functional validation as pathogenic or benign in disease pathology in specialist laboratories creating major delays in patient diagnosis. In this study we test a rapid genetic variant assessment pipeline using an EHMT1 (Euchromatin histone methyltransferase 1; EHMT1 p.Gln1144Ter) genetic variant that is pathogenic for Kleefstra Syndrome. Precise CRISPR homology directed (HDR) gene editing introduced the single nucleotide genetic variant in iPS cells and EHMT1_SNV cell clones were rapidly identified with amplicon sequencing. Induction of neural differentiation and RNA sequencing determined differences in differentiation at the gene and transcription factor level. The applied CRISPR HDR methodology was rapid and reliable for the introduction of SNVs in iPSCs for subsequent neuronal cell differentiation. Key features of Kleefstra Syndrome were identified, with involvement of key transcription factors REST and SP1 in disease mechanisms. This study indicates that precise iPSC gene editing and changes in disease modelling pathways can contribute to disease diagnosis and understanding of mechanisms.
2021-06-23 | GSE178646 | GEO
Project description:Wu C, Tatavarty V, Jean-Beltran PM, Guerrero A, Keshishian H, Krug K, MacMullan M, de Arce KP, Carr SA, Cottrell J, Turrigiano GG. 2021
Homeostatic synaptic plasticity requires widespread remodeling of synaptic signaling and scaffolding networks, but the role of posttranslational modifications in this process has not been systematically studied. Here we analyzed changes in the phosphoproteome during synaptic scaling up and down and found wide-spread and temporally complex changes. These included 424 bidirectionally modulated phosphosites that were strongly enrichment for synapse-associated proteins, including the ASD-associated synaptic scaffold protein Shank3. Shank3 was dephosphorylated at two highly conserved sites (rat S1586 and S1615) during scaling up, and hyperphosphorylated during scaling down. These changes modified the synaptic localization of Shank3 during scaling, and phosphomimetic or deficient mutants of Shank3 prevented scaling up or down, respectively. Finally, we found that dephosphorylation of these sites via PP2A activity was essential for the maintenance of synaptic scaling up. Thus Shank3 undergoes an activity-dependent switch between hypo- and hyperphosphorylation at S1586/ S1615, that is necessary to enable scaling up or down, respectively. More broadly, our data suggest that widespread and bidirectional changes in the synaptic phosphoproteome are essential for the functional reconfiguration of synaptic scaffolds during homeostatic plasticity.
2021-07-30 | MSV000087926 | MassIVE
Project description:Neuronal networks are subject to fluctuations in both the magnitude and frequency of inputs, requiring plasticity mechanisms to stabilize network activity. Homeostatic synaptic scaling is a form of synaptic plasticity that adjusts the strength of neuronal connections up or down in response to large changes in input. Although homeostatic plasticity requires changes in gene expression, there is only limited data describing the molecular changes associated with homeostatic scaling, focusing mostly on the expression mechanisms involving glutamate receptors. The fact that neuronal networks can be scaled up (in response to reduced activity) or down (in response to enhanced activity) provides a unique opportunity to examine the molecular and proteomic response to opposite ends of the phenotypic spectrum of synaptic plasticity. Here we first demonstrate that homeostatic scaling required protein synthesis. We then examined the plasticity-induced changes in the newly-synthesized neuronal proteome of neurons to identify the landscape of proteomic changes that contribute to opposing forms of homeostatic plasticity. Cultured rat hippocampal neurons (21 DIV) underwent homeostatic upscaling or downscaling (treatments with TTX and Bicucculine, respectively). We used BONCAT (BioOrthogonal Non-Canonical Amino acid Tagging) to metabolically label, capture and identify newly-synthesized proteins, detecting and analysing 5940 newly-synthesized proteins using liquid chromatography-coupled tandem mass spectrometry and label-free quantitation. Neither up- or down-scaling produced changes in the number of different proteins translated. Rather, our findings indicate that synaptic up- and down-scaling elicit opposing translational regulation of several molecular pathways, producing targeted adjustments in the neuronal proteome. We detected ~ 300 differentially regulated proteins involved in neurite outgrowth, reorganization of nerve terminals, axon guidance and targeting, neurotransmitter transport, filopodia assembly, excitatory synapses and glutamate receptor complexes. These proteins include well-characterized mediators of synaptic plasticity, e.g. the ionotropic glutamate receptor complex that is down-regulated during down-scaling and coordinately upregulated during upscaling. We also identified differentially regulated proteins that in addition to their regulation in homeostatic plasticity, are also associated with multiple diseases and disorders, including intellectual disability, schizophrenia, epilepsy, and Parkinson’s disease.
2016-12-22 | PXD004889 | Pride