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Berto, S.

Publications and source records attributed to Berto, S..

At least 19 recordsLinked to original sources

Sensory neurons gate a cortical plasticity window for immune encoding

Activity-dependent plasticity allows brain circuits to encode experience, but this has been established with brief stimuli. Immune responses develop over days and are represented in the insular cortex (IC). How the cortex encodes experiences with this temporal structure is unknown. Here we show that Trpv1+ sensory neurons open a multi-day cortical plasticity window matched to the immune response. Following peripheral immune challenges, Parvalbumin-expressing inhibitory interneurons are activated first, restricting plasticity. Vasoactive intestinal peptide-expressing interneurons respond two days later, disinhibiting IC excitatory neurons. Weaker challenges trigger the first phase but not the second, and preventing the transition blocks immune encoding, whereas lowering inhibition beforehand does not. These results identify a body-to-brain mechanism that gates cortical plasticity on the timescale of slowly evolving physiological experience.

neuroscience↗

A Neurotensin Brake on Exploratory Drive under Persistent Threat

Avoidance behavior is an adaptive response that delays exploration to promote survival. Avoidance is enhanced by psychological stress and is a hallmark of many neuropsychiatric disorders. Neural circuits that control avoidance by integrating stressful stimuli and modulating exploratory behavior remain underexplored. Elucidating the functional dynamics of this highly conserved phenomenon and the underlying neural mechanism of avoidance is an important open-ended question, with relevance to understanding both innate behaviors and neuropsychiatric disorders. Using predator odor as an innate, chronic stressor to increase avoidance behaviors in mice, we identified a neural population in the lateral septum (LS) that integrates threat information and modulates latency to explore. Calcium recordings in freely exploring mice combined with activity-based transcriptomics revealed that predator-responsive LS neurons are GABAergic and express neurotensin (LSNT). Further, single nuclei RNA-seq analysis revealed that among predator-responsive neurons, NT-enriched inhibitory clusters are predominant. Chronic activation of LSNT neurons induces avoidance behaviors in the absence of predator odor, while synaptic silencing of this population abrogates predator-enhanced avoidance. Using transgenic mouse models to indelibly tag predator-responsive neurons, we defined the downstream circuit that connects the encoding of predator odor information to the lateral hypothalamus. Projection-specific activation of LSNT[->]LHA neurons recapitulate stress-induced avoidance behaviors in mice. Finally, we showed that deletion of neurotensin from LS neurons prevented the effects of predator odor on exploration. Together, these findings offer a genetically-and projection-defined, top-down circuit linking the limbic neurotensinergic system to chronic psychological stress and avoidance behaviors in mice.

neuroscience↗

Characterization of Electrophysiological and Transcriptomic Alterations in Patient-Derived Neurons from CHAMP1 Syndrome

Mutations in chromosome alignment maintaining phosphoprotein 1 (CHAMP1) have been linked to neurodevelopmental disorders characterized by intellectual disability, developmental delay, and autism spectrum disorder. However, the cellular and electrophysiological mechanisms by which CHAMP1 mutations disrupt human neuronal development remain poorly understood. In the present study, we used patient-derived induced pluripotent stem cells (iPSCs) carrying two pathogenic CHAMP1 mutations and generated neural progenitor cells (NPCs) and excitatory neurons to investigate the effects of each mutation on neuronal maturation and function, DNA repair, and gene expression. Proliferative capacity declines with CHAMP1 dosage, while DNA repair dysfunction is allele-specific. Whole-cell patch-clamp electrophysiology revealed that CHAMP1 mutant neurons exhibit significant alterations in intrinsic membrane properties during early developmental stages, including depolarized resting membrane potential, reduced action potential firing, and impaired waveform kinetics. These functional deficits were accompanied by reduced sodium and potassium current densities, suggesting impaired ion channel accumulation during neuronal maturation. Furthermore, recordings of spontaneous excitatory postsynaptic currents indicated altered synaptic activity and reduced proportions of synaptically active neurons. Morphological analyses showed that CHAMP1-deficient neurons exhibit impaired neurite outgrowth and branching, supporting a defect in neuronal maturation. Single-nucleus transcriptomic profiling further revealed delayed developmental trajectories and mutation-specific dysregulation of synaptic gene programs enriched for autism, ADHD, and epilepsy risk genes. Together, these findings demonstrate that CHAMP1 mutations disrupt multiple aspects of neuronal development, including homologous recombination (HR) dysfunction in NPCs, membrane excitability, ion channel function, and synaptic connectivity. Our results provide insights into the neurobiological consequences of CHAMP1 mutations and establish patient-derived neurons as a platform to investigate cellular pathophysiology and potential therapeutic strategies for CHAMP1-associated neurodevelopmental disorders.

neuroscience↗

Region-specific cortico-striatal transcriptomic remodeling following early postnatal dopaminergic disturbance

Dopamine signaling plays critical roles in postnatal brain development, yet the molecular consequences of early dopaminergic disturbance remain incompletely understood. Here, we investigated transcriptomic alterations in the prefrontal cortex (PFC) and striatum (STR) of mice subjected to early postnatal dopaminergic disturbance by 6-hydroxydopamine (6-OHDA) treatment. Using bulk RNA sequencing (RNA-seq) and weighted gene co-expression network analysis (WGCNA), we identified 369 differentially expressed genes (DEGs) in the PFC, 493 DEGs in the STR, and 32 co-expression modules with region-specific expression patterns. Functional enrichment analyses showed that PFC DEGs were associated with cortical development, plasma membrane signaling, and transcriptional regulation, whereas STR DEGs were enriched for striatal development, locomotion, extracellular matrix organization, and amphetamine response. Co-expression network analysis further identified module-specific enrichments related to developmental, synaptic, metabolic, immune-related, and transcriptional programs. DEG sets from both regions also overlapped with genes implicated in attention-deficit/hyperactivity disorder (ADHD) and other neuropsychiatric disorders. Together, these findings reveal region-specific cortico-striatal transcriptomic remodeling following early postnatal dopaminergic disturbance and identify molecular programs that may link developmental dopaminergic perturbation to later behavioral phenotypes. HighlightsO_LIEarly dopaminergic disturbance reshapes cortico-striatal transcriptomes C_LIO_LIPFC changes were linked to developmental and transcriptional programs C_LIO_LISTR changes were linked to locomotion and extracellular matrix programs C_LIO_LINetwork analysis revealed region-specific developmental and synaptic programs C_LI

neuroscience↗

Characterize Oral-to-Blood Microbial DNA Translocation in Individuals with Cocaine Use Disorder

BackgroundCocaine disrupts gut barriers in animal models, potentially enabling microbial translocation and inflammation in the periphery and central nervous system (CNS), but its direct role in inducing inflammation remains controversial. This study aimed to determine if the oral cavity is a source of circulating microbial DNA translocation in individuals with current cocaine use disorder (CUD). ResultsA cross-sectional case-control study was conducted, comparing CUD and demographically matched non-drug controls. Ten CUD (via smoking or vaping) and 24 controls provided paired saliva and blood samples. Microbial 16S rRNA V4 region was sequenced in isolated microbial DNA from saliva and plasma. Single-cell RNA sequencing (scRNAseq) was analyzed in human peripheral blood mononuclear cells. Saliva from CUD, but not plasma, exhibited reduced alpha diversity and altered beta diversity, characterized by enriched Streptococcus and depleted Fusobacterium, Neisseria, and other taxa relative to controls. Controls exhibited low to undetectable microbial translocation in plasma. By contrast, plasma displayed CUD-specific oral enrichment of several Streptococcal species and evidence of translocation into the bloodstream. S. parasanguinis, but not cocaine alone, induced IL-1{beta} and TNF- production in human primary monocytes in vitro. scRNAseq further revealed innate immune activation, impaired T cell function, and heightened susceptibility to infection in CUD. ConclusionsThis pilot study demonstrating that CUD via smoking or snorting exhibited oral microbial dysbiosis and selective oral-to-blood microbial translocation in vivo. These findings suggest that a compromised oral-to-blood barrier, rather than cocaine itself, promotes immune perturbations in CUD.

microbiology↗

Oxidation of ΔFOSB at Cys172 Controls Hippocampal Gene Targets and Learning

Imbalance of reduction/oxidation (redox) in the brain is associated with numerous diseases including Alzheimers disease (AD), substance abuse disorders, and stroke. Moreover, cognitive decline can be caused by neuronal dysfunction that precedes cell death, and this dysfunction is in part produced by altered gene expression. However, the mechanisms by which redox state controls gene expression in neurons are not well understood. {Delta}FOSB is a neuronally enriched transcription factor critical for orchestrating gene expression underlying memory, mood, and motivated behaviors. It is dysregulated in many conditions including AD. We showed recently that {Delta}FOSB forms a redox-sensitive disulfide bond between cysteine 172 (C172) of {Delta}FOSB and C279 of its preferred binding partner JUND. This bond works as a redox switch to control DNA-binding, based on studies of recombinant proteins in vitro. Here, we show that this redox control of {Delta}FOSB function in vitro is conserved in vivo. We show that {Delta}FOSB C172 forms a redox-sensitive disulfide bond with JUND that regulates the stability of this AP1-transcription factor complex and its binding to DNA in cells. We also validate the formation of {Delta}FOSB-containing complexes held together via disulfide bonds in mouse brain in vivo. We show that exogenous oxidative stress reduces {Delta}FOSB binding to gene targets in mouse brain and that Fosb C172S knock-in mice, which lack a functional {Delta}FOSB redox switch, are insensitive to this oxidation-dependent reduction in target gene binding, demonstrating that {Delta}FOSB is regulated by a redox switch that modulates binding to target genes in the hippocampus. Finally, we demonstrate that FosB C172S knock-in mice are less sensitive to cognitive dysfunction induced by oxidative stress. This evidence supports {Delta}FOSB as an important mediator of oxidative stress-driven changes in gene expression and cognition and implicates {Delta}FOSB as a possible therapeutic target for diseases associated with oxidative stress in the brain, including AD.

neuroscience↗

Thioredoxin Reductase 1 inhibition triggers ferroptosis in KRAS-independent lung cancers

Lung cancers that harbor wild type KRAS (KRAS-WT) represent a molecularly diverse subset of tumors that often lack targeted therapeutic options. Using synthesized gold(I)-based inhibitors, a multi-omics approach, and functional validation, we identified Thioredoxin reductase 1 (TXNRD1), encoding as a selective vulnerability in KRAS-WT and oncogenic KRAS mutant (KM)-independent lung cancer (LC). Mechanistically, TRXR1 blockade induces ferroptosis through glutathione depletion, lipid reactive oxygen species (ROS) accumulation, and HMOX1-dependent iron overload in KRAS-WT LC both in vitro and in vivo. Furthermore, while KM LC cells are intrinsically resistant to TRXR1 inhibition, KMLC cells that acquire resistance to KRAS inhibitors (KRASi) undergo a redox shift that renders them sensitive to TRXR1 inhibition, uncovering a potential novel therapeutic vulnerability in KRASi-refractory tumors. These findings establish TRXR1 as a targetable redox checkpoint in KRAS-WT and KRASi-resistant lung cancers and support further development of TRXR1 inhibitors.

cancer biology↗

Developmental Stage-Dependent Transcriptomic Responses to Neonatal Intraventricular Hemorrhage

Neonatal intraventricular hemorrhage (IVH) is a major complication of preterm birth, yet how developmental stage influences the brains response to injury remains unclear. We performed single-nucleus RNA sequencing on rat brains 24 hours after IVH at postnatal day 2 (PND2) or day 5 (PND5) to define transcriptional responses across cell types. We identified 42 distinct cell populations and found that PND5 brains exhibited a markedly stronger immune and inflammatory response to IVH, with a threefold increase in differentially expressed genes compared to PND2. Microglia were the most perturbed cell type at both stages, showing increased oxidative stress and polarization toward both pro- and anti-inflammatory phenotypes at PND5. Ligand-receptor and regulon analysis revealed a shift from reparative IGF2 and TGF-{beta} signaling at PND2 to proinflammatory Wnt signaling and activation of Runx1 and Stat5 at PND5. These findings highlight the importance of developmental timing in shaping the neuroimmune response to IVH and identify potential stage-specific therapeutic targets.

neuroscience↗

Stimulation modulates cell assemblies linked with gene networks in the human temporal cortex ex vivo

Deep brain stimulation of the temporal cortex can enhance learning and memory in the face of cognitive impairment. Despite the potential of such therapies, the neural and genetic mechanisms underlying the effect of stimulation on human brain circuits are not understood. To explicate direct mechanisms of neural modulation elicited by brain stimulation, we developed an ex vivo approach utilizing microelectrode array stimulation and recording of resected temporal cortex from neurosurgical patients. We find that stimulation preferentially increases firing rates in pyramidal cells compared to interneurons and also strengthens cell assemblies. Using single cell multiomics, we link the observed physiological changes to cell type-specific gene expression patterns. We detail gene regulatory networks that indicate preferential involvement of specific excitatory neuron subtypes and the response of non-neurons. We conclude that the overall impact of stimulation on the human temporal cortex is activation of specific excitatory neurons and enhanced cell assembly activity, and that these changes are supported by gene networks involving immediate early, synaptic, and ion channel genes. Our findings establish a foundation to identify targetable cell type-specific genetic signatures that may be harnessed for therapeutic benefit in future neuromodulation strategies.

neuroscience↗

Direct interoceptive input to the insular cortex shapes learned feeding behavior

The insular cortex (insula) is an interoceptive hub, which senses internal states such as hunger, thirst, pain, and emotions. Previous studies suggest that the insula directly senses internal states, but the mechanisms remain elusive. We identified a population of leptin receptor-positive cells with a unique morphology in the insula (INSLepR). Based on leptins known role in signaling adiposity, we hypothesized that INSLepR neurons detect internal states to regulate food intake and body weight. Accordingly, we found that intra-insula leptin administration or optogenetic stimulation of INSLepR neurons impacts feeding behavior. Moreover, INSLepR neuron activity encodes feeding bouts in an internal-state dependent manner, and leptin alters insula neural dynamics in response to feeding, while also reshaping the transcriptome. Taken together, our data supports a model for direct interoceptive input to the insula, in which INSLepR cells integrate adiposity level signals to regulate feeding and body weight in a learned manner.

neuroscience↗

Alpha-1 Antitrypsin Overexpressing Mesenchymal Stem/Stromal Cells Reverses Type 1 Diabetes via Promoting Treg Function and CD8+ T cell exhaustion

Mesenchymal stem/stromal cell (MSC) therapy holds great promise as both a therapeutic option and as a biofactory, as cells produce therapeutic proteins to augment their efficacy in disease treatment. This study investigates the therapeutic effects and the mechanistic insights of alpha-1 antitrypsin overexpressing MSCs (AAT-MSCs) in diabetes prevention and treatment. A single infusion of AAT-MSCs not only delayed diabetes onset but reversed new-onset type 1 diabetes (T1D) in the nonobese diabetic (NOD) mice. Using single-cell RNA sequencing, flow cytometry, and functional analyses, we characterized the impact of AAT-MSCs on immune cells, particularly CD4+ and CD8+ T cells, in pancreatic lymph nodes (PLNs) and islets of NOD mice. AAT-MSCs enhanced the immunosuppressive function and the communication of regulatory T cells (Tregs) with other immune cells while reducing the numbers of T helper 1 (Th1) cells and CD8+ cytotoxic T cells. In vitro experiments further confirmed the capacity of AAT-MSCs to promote the proliferation of Tregs, which consequently fostered an exhausted phenotype in CD8+ T cells, thereby facilitating {beta} cell survival and potentially aiding in diabetes remission. Thus, our findings underscore the significant protective effects of AAT-MSCs, delineate their novel mechanistic insight on recipient immune cells, and provide evidence for the clinical application of AAT-MSCs in treating T1D.

cell biology↗

Dynamic Regulation Of The Chromatin Environment By ASH1L Modulates Human Neuronal Structure And Function

Precise regulation of the chromatin environment through post-translational histone modification modulates transcription and controls brain development. Not surprisingly, mutations in a large number of histone-modifying enzymes underlie complex brain disorders. In particular, the histone methyltransferase ASH1L modifies histone marks linked to transcriptional activation and has been implicated in multiple neuropsychiatric disorders. However, the mechanisms underlying the pathobiology of ASH1L-asociated disease remain underexplored. We generated human isogenic stem cells with a mutation in ASH1Ls catalytic domain. We find that ASH1L dysfunction results in reduced neurite outgrowth, which correlates with alterations in the chromatin profile of activating and repressive histone marks, as well as the dysregulation of gene programs important for neuronal structure and function implicated in neuropsychiatric disease. We also identified a novel regulatory node implicating both the SP and Kruppel-like families of transcription factors and ASH1L relevant to human neuronal development. Finally, we rescue cellular defects linked to ASH1L dysfunction by leveraging two independent epigenetic mechanisms that promote transcriptional activation. In summary, we identified an ASH1L-driven epigenetic and transcriptional axis essential for human brain development and complex brain disorders that provide insights into future therapeutic strategies for ASH1L-related disorders.

neuroscience↗

Single-nucleus and spatial landscape of the sub-ventricular zone in human glioblastoma

The sub-ventricular zone (SVZ) is the most well-characterized neurogenic area in the mammalian brain. We previously showed that in 65% of patients with glioblastoma (GBM), the SVZ is a reservoir of cancer stem-like cells that contribute to treatment resistance and emergence of recurrence. Here, we built a single-nucleus RNA-sequencing-based microenvironment landscape of the tumor mass (T_Mass) and the SVZ (T_SVZ) of 15 GBM patients and 2 histologically normal SVZ (N_SVZ) samples as controls. We identified a mesenchymal signature in the T_SVZ of GBM patients: tumor cells from the T_SVZ relied on the ZEB1 regulatory network, whereas tumor cells in the T_Mass relied on the TEAD1 regulatory network. Moreover, the T_SVZ microenvironment was predominantly characterized by tumor-supportive microglia, which spatially co-exist and establish heterotypic interactions with tumor cells. Lastly, differential gene expression analyses, predictions of ligand-receptor and incoming/outgoing interactions, and functional assays revealed that the IL-1{beta}/IL-1RAcP and Wnt-5a/Frizzled-3 pathways are therapeutic targets in the T_SVZ microenvironment. Our data provide insights into the biology of the SVZ in GBM patients and identify specific targets of this microenvironment.

cancer biology↗

High affinity chimeric antigen receptor signaling induces an inflammatory program in human regulatory T cells

Regulatory T cells (Tregs) are promising cellular therapies to induce immune tolerance in organ transplantation and autoimmune disease. The success of chimeric antigen receptor (CAR) T-cell therapy for cancer has sparked interest in using CARs to generate antigen-specific Tregs. Here, we compared CAR with endogenous T cell receptor (TCR)/CD28 activation in human Tregs. Strikingly, CAR Tregs displayed increased cytotoxicity and diminished suppression of antigen-presenting cells and effector T (Teff) cells compared with TCR/CD28 activated Tregs. RNA sequencing revealed that CAR Tregs activate Teff cell gene programs. Indeed, CAR Tregs secreted high levels of inflammatory cytokines, with a subset of FOXP3+ CAR Tregs uniquely acquiring CD40L surface expression and producing IFN{gamma}. Interestingly, decreasing CAR antigen affinity reduced Teff cell gene expression and inflammatory cytokine production by CAR Tregs. Our findings showcase the impact of engineered receptor activation on Treg biology and support tailoring CAR constructs to Tregs for maximal therapeutic efficacy. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=54 SRC="FIGDIR/small/587467v1_ufig1.gif" ALT="Figure 1"> View larger version (20K): org.highwire.dtl.DTLVardef@11e5bd8org.highwire.dtl.DTLVardef@1fe86forg.highwire.dtl.DTLVardef@d4eb2borg.highwire.dtl.DTLVardef@9b89d1_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

Adaptor protein complex 2 in the orbitofrontal cortexpredicts alcohol use disorder

Alcohol use disorder (AUD) is a life-threatening disease characterized by compulsive drinking, cognitive deficits, and social impairment that continue despite negative consequences. The inability of individuals with AUD to regulate drinking may involve functional deficits in cortical areas that normally balance actions that have aspects of both reward and risk. Among these, the orbitofrontal cortex (OFC) is critically involved in goal-directed behavior and is thought to maintain a representation of reward value that guides decision making. In the present study, we analyzed post-mortem OFC brain samples collected from age- and sex-matched control subjects and those with AUD using proteomics, bioinformatics, machine learning, and reverse genetics approaches. Of the 4,500+ total unique proteins identified in the proteomics screen, there were 47 proteins that differed significantly by sex that were enriched in processes regulating extracellular matrix and axonal structure. Gene ontology enrichment analysis revealed that proteins differentially expressed in AUD cases were involved in synaptic and mitochondrial function, as well as transmembrane transporter activity. Alcohol-sensitive OFC proteins also mapped to abnormal social behaviors and social interactions. Machine learning analysis of the post-mortem OFC proteome revealed dysregulation of presynaptic (e.g., AP2A1) and mitochondrial proteins that predicted the occurrence and severity of AUD. Using a reverse genetics approach to validate a target protein, we found that prefrontal Ap2a1 expression significantly correlated with voluntary alcohol drinking in male and female genetically diverse mouse strains. Moreover, recombinant inbred strains that inherited the C57BL/6J allele at the Ap2a1 interval consumed higher amounts of alcohol than those that inherited the DBA/2J allele. Together, these findings highlight the impact of excessive alcohol consumption on the human OFC proteome and identify important cross-species cortical mechanisms and proteins that control drinking in individuals with AUD.

neuroscience↗

NPAS4 supports drug-cue associations and relapse-like behavior through regulation of the cell type-specific activation balance in the nucleus accumbens

Use of addictive substances creates powerful drug-cue associations that often trigger relapse. Drug seeking is gated in the nucleus accumbens (NAc) by competing activation of D1 dopamine receptor-expressing medium spiny neurons (D1-MSNs) that promote, and D2 dopamine receptor-expressing neurons (D2-MSNs) that oppose, drug seeking. We show here that the ensemble of neurons in the NAc that induce the neuronal activity-regulated transcription factor, Neuronal PAS Domain Protein 4 (NPAS4), is required for cocaine-context associations. In addition, NPAS4 functions within NAc D2-MSNs to govern the activation balance of NAc D1-MSNs and D2-MSNs necessary for drug-context memories and cue-induced cocaine, but not sucrose, seeking. NPAS4 regulates drug-cue associations and preponderant D1-MSN activation by influencing a program of gene expression that blocks cocaine-induced potentiation of prefrontal cortical excitatory drive onto D2-MSNs. Together our findings reveal that NPAS4 is a key player governing NAc MSN cell-type activation balance and promoting drug-cue associations and relapse vulnerability.

neuroscience↗

Targeting de novo lipogenesis and the Lands cycle induces ferroptosis in KRAS-mutant lung cancer

Mutant KRAS (KM) is the most common oncogene in lung cancer (LC). KM regulates several metabolic networks, but their role in tumorigenesis is still not sufficiently characterized to be exploited in cancer therapy. To identify metabolic networks specifically deregulated in KMLC, we characterized the lipidome of genetically engineered LC mice, cell lines, patient derived xenografts and primary human samples. We also determined that KMLC, but not EGFR-mutant (EGFR-MUT) LC, is enriched in triacylglycerides (TAG) and phosphatidylcholines (PC). We also found that KM upregulates fatty acid synthase (FASN), a rate-limiting enzyme in fatty acid (FA) synthesis promoting the synthesis of palmitate and PC. We determined that FASN is specifically required for the viability of KMLC, but not of LC harboring EGFR-MUT or wild type KRAS. Functional experiments revealed that FASN inhibition leads to ferroptosis, a reactive oxygen species (ROS)-and iron-dependent cell death. Consistently, lipidomic analysis demonstrated that FASN inhibition in KMLC leads to accumulation of PC with polyunsaturated FA (PUFA) chains, which are the substrate of ferroptosis. Integrating lipidomic, transcriptome and functional analyses, we demonstrated that FASN provides saturated (SFA) and monounsaturated FA (MUFA) that feed the Lands cycle, the main process remodeling oxidized phospholipids (PL), such as PC. Accordingly, either inhibition of FASN or suppression of the Lands cycle enzymes PLA2 and LPCAT3, promotes the intracellular accumulation of lipid peroxides and ferroptosis in KMLC both in vitro and in vivo. Our work supports a model whereby the high oxidative stress caused by KM dictates a dependency on newly synthesized FA to repair oxidated phospholipids, establishing a targetable vulnerability. These results connect KM oncogenic signaling, FASN induction and ferroptosis, indicating that FASN inhibitors already in clinical trial in KMLC patients (NCT03808558) may be rapidly deployed as therapy for KMLC.

cancer biology↗

Non-coding enhancer RNA regulates NPAS4 in the mPFC to control chronic stress-induced anhedonia-like behavior

Chronic stress can produce reward system deficits (i.e. anhedonia) and other common symptoms associated with depressive disorders, as well as neural circuit hypofunction in the medial prefrontal cortex (mPFC). However, the molecular mechanisms by which chronic stress promotes depressive-like behavior and hypofrontality remain unclear. We show here that the neuronal activity-regulated transcription factor, NPAS4, in the mPFC is regulated by chronic social defeat stress (CSDS), and its required in this brain region for CSDS-induced changes in sucrose preference and natural reward motivation. Interestingly, NPAS4 is not required for CSDS-induced social avoidance or anxiety-like behavior. We also find that mPFC NPAS4 is required for CSDS-induced reduction of pyramidal cell dendritic spine density, revealing a relationship between mPFC dendritic spine changes and anhedonia-like behavior, but not social avoidance behavior. Finally, transcriptomic analysis from the mPFC revealed that NPAS4 influences expression of numerous genes linked to glutamatergic synapses and ribosomal function, as well as many dysregulated genes observed in common neuropsychiatric disorders, including depression. Together our findings reveal an essential role for the activity-regulated transcription factor, NPAS4, in chronic stress-induced mPFC hypofunction and anhedonia.

neuroscience↗