Neuronal activity, TGFβ signaling and unpredictable chronic stress affect transcription of Gadd45 family members in vitro and in vivo [MeDIP-Seq]
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ABSTRACT: Neuronal activity is altered in several neurological and psychiatric diseases. Upon depolarization not only neurotransmitters are released but also cytokines and other activators of signaling cascades. Unraveling their complex implication in transcriptional control in receiving cells will contribute to understand specific central nervous system (CNS) pathologies and will be of therapeutical interest. In this study we depolarized mature hippocampal neurons in vitro using KCl and revealed increased release not only of Brain-derived neurotrophic factor (BDNF), but also of Transforming growth factor beta (TGFB). Neuronal activity together with BDNF and TGFB controls transcription of DNA modifying enzymes specifically members of the DNA-damage-inducible (Gadd) family, Gadd45a, Gadd45b, and Gadd45g. MeDIP followed by massive parallel sequencing and transcriptome analyses revealed less DNA methylation upon KCl treatment. Thereby, psychiatric disorder-related genes, namely Tshz1, Foxn3, Jarid2, Per1, Map3k5, and Arc are transcriptionally activated and demethylated upon neuronal activation. To analyze whether misexpression of Gadd45 family members can be associated with psychiatric diseases, we applied unpredictable chronic mild stress (UCMS) as established model for depression to mice.UCMS lead to a reduced expression of Gadd45 family members. Taken together, our data demonstrate that Gadd45 family members are new putative targets for UCMS treatments.
Project description:Neuronal activity is altered in several neurological and psychiatric diseases. Upon depolarization not only neurotransmitters are released but also cytokines and other activators of signaling cascades. Unraveling their complex implication in transcriptional control in receiving cells will contribute to understand specific central nervous system (CNS) pathologies and will be of therapeutical interest. In this study we depolarized mature hippocampal neurons in vitro using KCl and revealed increased release not only of Brain-derived neurotrophic factor (BDNF), but also of Transforming growth factor beta (TGFB). Neuronal activity together with BDNF and TGFB controls transcription of DNA modifying enzymes specifically members of the DNA-damage-inducible (Gadd) family, Gadd45a, Gadd45b, and Gadd45g. MeDIP followed by massive parallel sequencing and transcriptome analyses revealed less DNA methylation upon KCl treatment. Thereby, psychiatric disorder-related genes, namely Tshz1, Foxn3, Jarid2, Per1, Map3k5, and Arc are transcriptionally activated and demethylated upon neuronal activation. To analyze whether misexpression of Gadd45 family members can be associated with psychiatric diseases, we applied unpredictable chronic mild stress (UCMS) as established model for depression to mice.UCMS lead to a reduced expression of Gadd45 family members. Taken together, our data demonstrate that Gadd45 family members are new putative targets for UCMS treatments.
Project description:Brain-Derived Neurotrophic Factor (BDNF) is crucial for neuronal survival, differentiation, synaptic plasticity, memory formation, and neurocognitive health. Molecular mechanisms of BDNF promoting cellular survival and synaptic plasticity have been intensely studied, yet its role in genome regulation is obscure. Using human induced pluripotent stem cell (hiPSC)-derived neurons via lentiviral delivery of the neuronal transcription factor Ngn2, we performed a temporal profiling (1h, 6h and 10h) of chromatin accessibility upon BDNF treatment or depolarization (KCl) to identify BDNF-specific chromatin-to-gene expression programs.
Project description:Brain-Derived Neurotrophic Factor (BDNF) is crucial for neuronal survival, differentiation, synaptic plasticity, memory formation, and neurocognitive health. Molecular mechanisms of BDNF promoting cellular survival and synaptic plasticity have been intensely studied, yet its role in genome regulation is obscure. Using human induced pluripotent stem cell (hiPSC)-derived neurons via lentiviral delivery of the neuronal transcription factor Ngn2, we performed a temporal profiling (1h, 6h and 10h) of chromatin accessibility upon BDNF treatment or depolarization (KCl) to identify BDNF-specific chromatin-to-gene expression programs.
Project description:Neuronal activity induced by Brain-Derived Neurotrophic Factor (BDNF) is crucial for neuronal survival, differentiation, synaptic plasticity, memory formation, and neurocognitive health. Molecular mechanisms of BDNF promoting cellular survival and synaptic plasticity have been intensely studied, yet its role in genome regulation is obscure. Here, through temporal profiling of chromatin accessibility and transcription in mouse primary cortical neurons upon BDNF treatment or depolarization (KCl), we identified BDNF-specific chromatin-to-gene expression programs. Our analyses revealed that enhancer activation is an early event in the regulatory control of BDNF treated neurons, where bZIP pioneered chromatin opening and co-regulatory transcription factors (Homeobox, EGRs, and CTCF) cooperate to induce fine-grained transcription. Deleting such cis-regulatory sequences decreased the BDNF mediated expression of Arc, a key regulator of synaptic plasticity. Furthermore, BDNF-induced accessible regions are linked to preferential exon usage of neurodevelopmental disorder related genes and heritability of neuronal complex traits. In conclusion, this work provides a comprehensive view of BDNF-mediated genome regulatory features and emphasizes the usage of genomic approaches on dissecting mammalian neuronal activity.
Project description:We studied the effects of different stimuli on on the subcellular proteome of neurons differentiated from murine embryonic stem cells (ESC). We focused on the changes in the chromatin-bound fraction to elucidate specific differences in the gene regulatory machinery activated upon stimulation with Brain-derived neurotrophic factor (BDNF) or a general membrane-depolarization stimulus, potassium chloride (KCl).
Project description:Neuronal activity, TGFβ signaling and unpredictable chronic stress affect transcription of Gadd45 family members in vitro and in vivo
Project description:Neuronal activity, TGFβ signaling and unpredictable chronic stress affect transcription of Gadd45 family members in vitro and in vivo [Affymetrix]
Project description:Neuronal activity, TGFβ signaling and unpredictable chronic stress affect transcription of Gadd45 family members in vitro and in vivo [MeDIP-Seq]
Project description:Major depressive disorder (MDD) is a severe psychiatric disorder, characterized by deficits in GABAergic and glutamatergic signaling in cortical brain regions. Unpredictable chronic mild stress (UCMS), a murine stress model, induces behavioural and neurobiological changes reminiscent of MDD. Despite increasing knowledge of the cellular complexity of the cortical microcircuitry, our understanding of how distinct cell-types are impacted by UCMS is extremely limited. We thus endeavoured to determine the effect of UCMS on Pyramidal (PYR) cells and three classes of interneurons: Somatostatin (SST), Parvalbumin (PV), and Vasoactive intestinal peptide-expressing (VIP) cells in the medial prefrontal cortex. C57Bl/6 mice, exposed to UCMS or control housing for five weeks, were assessed with a battery of anxiety- and depressive-like behavioural tests. Laser-capture microdissection was used to isolate samples of microcircuit cell-types, which underwent RNA-sequencing. UCMS-exposed mice showed significantly elevated emotionality, and isolate cell-types showed robust specificity. Cell-types exhibited unique transcriptomic profiles after UCMS. Briefly, PYR-cells showed decreased signaling and post-synaptic receptor expression, SST-cells showed increased activation of the unfolded protein response, PV-cells showed increased axonal microtubule expression, and VIP-cells showed increased apoptotic signaling and altered cytoskeletal gene expression. Co-expression analyses revealed that these changes were largely correlated across cell-types and that UCMS increased transcriptome-wide co-expression between PYR and both PV and SST cells. Overall, these findings suggest decreased PYR, SST, and VIP-cell function, elevated PV-cell function, and identify the dysregulation of PYR-cells as a central locus of UCMS-induced transcriptomic change. Further studies interrogating potential antidepressant-like activity of compounds reversing these cell-specific changes are warranted.