A neuronal transcription factor is required in the prefrontal cortex for transcriptional and behavioral adaptation to chronic stress
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ABSTRACT: Stressful life events increase risk for depression, yet the molecular mechanisms by which stress is encoded in the brain to induce maladaptive behaviors are not well understood. Emerging evidence has shown that stress dysregulates gene expression in the brain, yet the cellular origin of these gene expression alterations has yet to be determined. To address this question, we used a chronic unpredictable stress (CUS) paradigm that drives depressive- and anxiety-like behaviors in male and female mice and single-nucleus transcriptomics to identify cell type-specific gene expression changes in the cortex. We find that neocortical excitatory neurons are particularly vulnerable to chronic stress exposure, and that CUS reprograms these cells to decrease transcription of synaptic genes involved in glutamatergic neurotransmission. We identify the ubiquitously expressed factor, Yin Yang 1 (YY1), as a key driver of the transcriptional reprogramming observed in excitatory neurons isolated from CUS mice. Selective depletion of YY1 in excitatory neurons of the prefrontal cortex (PFC) increases the stress sensitivity of mice, inducing depressive- and anxiety-related behaviors following an abbreviated stress exposure and deregulating expression of key stress-related genes in the PFC. Importantly, we find that YY1 functions in both males and females to facilitate stress coping. This work establishes a novel mechanism underlying chronic stress-induced behavior, in which epigenetic responses to stress in PFC excitatory neurons are mediated by stress-dependent YY1 activity. Our findings demonstrate how post-mitotic neurons adapt to stress experience and identify a novel molecular target that is generalizable to males and females for therapeutic treatment of stress-related neuropsychiatric disorders.
Project description:Recent studies implicate microglia alterations in the pathogenesis and pathophysiology of depression. For example, chronic unpredictable stress (CUS) in mice can cause degeneration of microglia and depressive-like symptoms, which can be reversed by microglia stimulating drugs. To further test the causal role of microglia in CUS-induced depression and its reversal by an anti-depressive procedure, we examined the effects of microglia depletion with the CSF-1 antagonist PLX5622 or pharmacological blockade of microglial activation with minocycline on normal mood-related behavior, CUS-induced depressive-like symptoms, and the amelioration of these symptoms by electroconvulsive treatment (ECT). We report that microglia-depleted mice showed no depression, anxiety or spatial memory disturbances. Microglia depletion had no effect on the development of CUS-induced depressive-like symptoms and suppressed neurogenesis, but it completely abrogated the beneficial effects of ECT on depression and neurogenesis, as well as on the all ECT-induced transcriptomic changes. ECT induced several morphological changes in microglia, suggestive of increased activation status, and blockade of this activation by minocycline attenuated the anti-depressive and pro-neurogenesis effect of ECT and reduced the number of contacts between microglia and neurogenic cells. The immune checkpoint gene Lag3, whose expression by microglia was increased following CUS, was the only microglial transcript significantly reduced by ECT. Furthermore, treatment of depressed-like mice with a LAG3 monoclonal antibody was further tested.
Project description:Exposure to early stress (ES) is known to enhance adult vulnerability for anxiety and depressive behaviors. The molecular and cellular pathways altered in response to ES that contribute to the establishment of a substrate for susceptibility to adult psychopathology are not well understood. Focusing on the prefrontal cortex (PFC), a brain region implicated in the modulation of emotional responses, we examined the consequences of the early stress experience of maternal separation (MS) on the adult PFC transcriptome. Microarray analysis identified alterations in genes associated with signal transduction, neuronal excitability, G-protein signaling and stress responses in the PFC of adult animals previously exposed to ES. Our results also indicated that the pattern of gene expression changes observed in ES animals contains a component in common with that induced by 5-HT2A/C receptor stimulation in control animals, suggesting enhanced 5-HT2A/C receptor-mediated signaling in ES animals. Further, our microarray results reveal that a history of ES alters the DOI-induced transcriptome in the PFC.
Project description:Bipolar disorder is a complex polygenetic disorder that is characterized by recurrent episodes of depression and mania, the heterogeneity of which is likely complicated by epigenetic modifications that remain to be elucidated. Here, we performed transcriptomic analysis of peripheral blood RNA from monozygotic twins discordant for bipolar disorder and identified a bipolar disorder-associated upregulated long non-coding RNA (lncRNA), AP1AR-DT. We observed that overexpression of AP1AR-DT in the mouse medial prefrontal cortex (mPFC) resulted in a reduction of both the total spine density and the spontaneous excitatory postsynaptic current (sEPSC) frequency of mPFC neurons, as well as depressive and anxiety-like behaviors. A combination of the results of brain transcriptome analysis of AP1AR-DT overexpressing mice brains with the known genes associated with bipolar disorder revealed that NEGR1, which encodes neuronal growth regulator 1, is one of the AP1AR-DT targets and is reduced in vivo upon gain of AP1AR-DT in mice. The results of the present study demonstrated that overexpression of recombinant Negr1 in the mPFC neurons of AP1AR-DTOE mice ameliorates depressive and anxiety-like behaviors and normalizes the reduced excitatory synaptic transmission induced by the gain of AP1AR-DT. Furthermore, the study provides evidence that AP1AR-DT reduces NEGR1 expression by competing for the transcriptional activator NRF1 in the overlapping binding site of the NEGR1 promoter region. The epigenetic and pathophysiological mechanism linking AP1AR-DT to the modulation of excitatory synaptic function provides etiological implications for bipolar disorder.
Project description:Bipolar disorder is a complex polygenetic disorder that is characterized by recurrent episodes of depression and mania, the heterogeneity of which is likely complicated by epigenetic modifications that remain to be elucidated. Here, we performed transcriptomic analysis of peripheral blood RNA from monozygotic twins discordant for bipolar disorder and identified a bipolar disorder-associated upregulated long non-coding RNA (lncRNA), AP1AR-DT. We observed that overexpression of AP1AR-DT in the mouse medial prefrontal cortex (mPFC) resulted in a reduction of both the total spine density and the spontaneous excitatory postsynaptic current (sEPSC) frequency of mPFC neurons, as well as depressive and anxiety-like behaviors. A combination of the results of brain transcriptome analysis of AP1AR-DT overexpressing mice brains with the known genes associated with bipolar disorder revealed that NEGR1, which encodes neuronal growth regulator 1, is one of the AP1AR-DT targets and is reduced in vivo upon gain of AP1AR-DT in mice. The results of the present study demonstrated that overexpression of recombinant Negr1 in the mPFC neurons of AP1AR-DTOE mice ameliorates depressive and anxiety-like behaviors and normalizes the reduced excitatory synaptic transmission induced by the gain of AP1AR-DT. Furthermore, the study provides evidence that AP1AR-DT reduces NEGR1 expression by competing for the transcriptional activator NRF1 in the overlapping binding site of the NEGR1 promoter region. The epigenetic and pathophysiological mechanism linking AP1AR-DT to the modulation of excitatory synaptic function provides etiological implications for bipolar disorder.
Project description:The interaction between cancer and depressive disorder remains unclear. In this study, we obtained patient data from TCGA and MDD-related (Major Depressive Disorder) genes from the GEO database and the sequencing data of the PDX model with chronic unpredictable stress (CUS). Molecular subtypes and a prognostic signature were generated based on the MDD-related genes obtained by differential expression analysis. According to our analysis, the gene signature was a promising biomarker in distinguishing the prognosis, the molecular or immune characteristics, and the depressive risk, as well as the therapy candidates for gastric adenocarcinoma patients.
Project description:In this study we employed the chronic unpredictable stress (CUS) rat model that leads to anxiety features comparable to humans and validated in several published reports as a well-characterized model of depression symptoms with high predictive validity. Cytokines and activated intracellular kinase levels were determined using high throughput multiplex assays. RNA from freshly isolated adipocytes was used to run whole genome expression microarray profiling in control and stressed rats. Adipocyte function was assessed via tritiated glucose uptake assay. The expression of four cytokines (TNFα, IL-1β, IL-6 and MCP-1) was validated via real-time PCR and the all showed increased expression levels with chronic unpredictable stress. Male rats were subjected to chronic unpredictable stress for 35 days and total body fat was measured. The analyses presented here represents data from experiments performed in 6 control and 6 stressed rats in parallel. All cells for RNA isolation were collected at the conclusion of the 35 day stress protocol.
Project description:Both the amygdala and the bed nucleus of the stria terminalis (BNST) have been implicated in maladaptive anxiety characteristic of anxiety disorders. However, the underlying circuit and cellular mechanisms have remained elusive. Here we show that mice with Erbb4 gene deficiency in somatostatin-expressing (SOM+) neurons exhibit heightened anxiety as measured in the elevated plus maze test and the open field test, two assays commonly used to assess anxiety-related behaviors in rodents. Using a combination of electrophysiological, molecular, genetic and pharmacological techniques we demonstrate that the abnormal anxiety in the mutant mice is caused by enhanced excitatory synaptic inputs onto SOM+ neurons in the central amygdala (CeA), and the resulting reduction in inhibition onto downstream SOM+ neurons in the BNST. Notably, our results indicate that an increase in dynorphin signaling in SOM+ CeA neurons mediates the paradoxical reduction in inhibition onto SOM+ BNST neurons, and that the consequent enhanced activity of SOM+ BNST neurons is both necessary for and sufficient to drive the elevated anxiety. Finally, we show that the elevated anxiety and the associated synaptic dysfunctions and increased dynorphin signaling in the CeA-BNST circuit of the Erbb4 mutant mice can be recapitulated by stress in wild-type mice. Together, our results unravel previously unknown circuit and cellular processes in the central extended amygdala that can cause maladaptive anxiety.
Project description:It remains unclear why many patients with depression do not respond to antidepressant treatment. In three cohorts of individuals with depression and treated with serotonin-norepinephrine reuptake inhibitor (N=424) we show that responders, but not non-responders, display an increase of GPR56 mRNA in the blood. In a small group of subjects we also show that GPR56 is also downregulated in the PFC of individuals with depression that died by suicide. In mice, we show that chronic stress induced Gpr56 downregulation in the blood and prefrontal cortex (PFC), which is accompanied by depression-like behaviour, and can be reversed by antidepressant treatment. Gpr56 knockdown in mouse PFC was is associated with depressive-like behaviors, executive dysfunction and poor response to antidepressant treatment. GPR56 peptide agonists had antidepressant-like effects and up-regulated AKT/GSK3/EIF4 pathways. Our findings uncover a potential role of GPR56 in antidepressant response.
Project description:Adolescent stress can impact health and well-being not only during adulthood of the exposed individual but even in future generations. To begin to unravel the molecular mechanisms underlying these long-term effects, we determined if stress administered to males during adolescence (F0) altered anxiety behaviors and gene expression profiles in the amygdala – a critical region in the control of emotional states – of their progeny in two generations (F1, F2). Male C57BL/6 mice underwent chronic unpredictable stress (CUS) for two-weeks during adolescence and were used to produce two generations of offspring. Male and female F1 and F2 animals were tested in behavioral assays to measure affective behavior and stress reactivity. Remarkably, transgenerational inheritance of paternal stress exposure produced a protective phenotype in the male, but not the female lineage. In behaviorally naïve mice (n = 5), mRNA from the amygdala was sequenced to determine the total transcriptomes and pathway analysis was employed to identify differentially expressed genes of functional interest. RNA-Seq analysis of the amygdala from F1 and F2 male offspring identified genes with altered expression in mice derived from fathers exposed to CUS. Among the differentially expressed pathway was ‘notch signaling’, which was significantly altered in F2 males. Therefore, we show that paternal stress exposure impacts future generations which manifest in behavioral changes and molecular adaptations.