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First-in-Class Small Molecule Inhibitor of Oncogene AVIL in Glioblastoma.

Glioblastoma multiforme (GBM) is the most prevalent and aggressive malignant primary brain tumor, marked by rapid growth, extensive invasiveness, and a median survival of only ∼15 months despite current multimodal therapy. To identify new therapeutic vulnerabilities, we investigated the actin-regulatory protein AVIL, previously implicated through a MARS-AVIL gene fusion in rhabdomyosarcoma. Comprehensive genomic and transcriptomic analyses across REMBRANDT, TCGA, and CGGA datasets revealed recurrent AVIL amplification and consistently elevated AVIL expression in GBM compared with normal brain tissue. AVIL was overexpressed across all GBM molecular subtypes and glioma stem cell (GSC) states but was nearly undetectable in normal astrocytes, neural stem cells, and brain tissues. Functional studies demonstrated that AVIL is both necessary and sufficient for glioma genesis: AVIL silencing eradicated GBM cells in vitro and suppressed xenograft growth in vivo, while AVIL overexpression enhanced proliferation, migration, and transformation. Mechanistically, AVIL drives tumor progression through actin cytoskeleton remodeling and activation of the FOXM1-LIN28B oncogenic pathway. Using a small molecule microarray screen, we identified a selective AVIL-binding compound (compound A) that potently inhibited GBM cell growth with minimal toxicity to normal astrocytes. Gene expression changes induced by compound A mirrored those following AVIL knockdown, indicating on-target activity. Compound A demonstrated robust antitumor efficacy in multiple preclinical GBM models, including orthotopic xenografts, GSC-derived tumors, patient-derived xenografts, and temozolomide-resistant GBM with favorable pharmacokinetics and blood-brain barrier penetration. The minimal AVIL expression in normal tissues and lack of phenotype in AVIL-deficient mice underscore its potential as a low-toxicity therapeutic target. Together, these findings establish AVIL as a critical oncogenic driver in GBM and introduce a first-in-class AVIL inhibitor with strong translational promise for precision neuro-oncology.

Glioblastoma

Validation of breast cancer as a risk factor for anxiety and depression: Insights from Mendelian randomization analysis.

This study employed Mendelian randomization (MR) analysis to confirm the association between breast cancer and the risk of anxiety and depression, and to explore the molecular mechanisms by which lipid nanoparticles of ketamine (LNP@Ket) modulate these behaviors in a mouse model of breast cancer. Through single-cell transcriptomic analysis, the study aimed to clarify nuclear factor erythroid 2-related factor 2 (Nrf2)'s role in the development of anxiety and depression in these mice. Analysis of patient data from genome-wide association study (GWAS) databases supported the link between breast cancer, anxiety, and depression. In vivo experiments demonstrated that treating breast cancer mice with LNP@Ket significantly reduced anxiety and depression behaviors. The synthesis of LNP@Ket and its subsequent analysis highlighted its inhibitory effects on these behaviors. Single-cell transcriptomic sequencing identified key cells and genes affected by LNP@Ket treatment, particularly emphasizing Nrf2. Upregulation of Nrf2 in astrocytes increased the expression of antioxidant enzymes and reduced pro-inflammatory cytokines, alleviating anxiety and depression symptoms by inhibiting neuroinflammation and neurodegeneration. This comprehensive study highlights the pivotal role of Nrf2 in the therapeutic efficacy of LNP@Ket for treating anxiety and depression in breast cancer mice.

Anxiety and depression behaviors

narrowPASEF: A Sample-Aware diaPASEF Method Optimization Strategy Improving Differential Proteomics Performance on Low-Abundance Proteins.

Recent instrumental and computational innovations in mass-spectrometry-based proteomics offer new promise in biomarker discovery, thanks to unprecedented proteome coverage and depth. Data-independent acquisition (DIA) methods are very promising in this context as they allow improved proteome coverage, reduced missing value rates, and enhanced quantification precision. However, DIA methods also suffer from their own challenges, such as increased data complexity, cycle times, and background noise. In this work, we propose a sample-aware diaPASEF method optimization strategy for a timsTOF platform. Thorough method optimizations have first been conducted on standard HeLa lysates. Then, a ground-truth calibrated sample series, consisting of a range of UPS amounts spiked into a complex Arabidopsis background, was used to mimic differential analyses under controlled conditions. These benchmark experiments demonstrate clear benefits of using narrowPASEF for differential protein discovery. Finally, our strategy was applied to real use case biological samples to conduct a differential analysis of purified mouse astrocyte cells across two different conditions. narrowPASEF improved the proteome depth by 13%, considering proteins quantified with a coefficient of variation (CV) of <20%, and led to a 68% (435 vs 729) increase in differentially expressed proteins. These results provide an opportunity for a more precise and comprehensive analysis of the biological functions of biomarkers, offering a more profound understanding of the disease mechanisms. The benefits of our sample-aware narrowPASEF strategy demonstrated the most substantial impact on low-abundance proteins. Overall, these results show promise for more valuable and robust biomarker discoveries in the future.

Proteomics

Proteoform profiling of endogenous single cells from rat hippocampus at scale.

We perform intact proteoform profiling of 10,809 endogenous single cells from the rat hippocampus using single-cell proteoform imaging mass spectrometry (scPiMS). scPiMS directly extracts whole proteins and demonstrates high throughput for MS-based single-cell proteomics compared with existing approaches. We develop an informatics workflow dedicated to this datatype and use it to assign neurons, astrocytes or microglia cell types according to their proteoform signatures.

Animals

A reproducible three-dimensional model of human brain tissue to investigate physiological and disease-associated microglia phenotypes.

Stem-cell-based in vitro models offer promising potential to elucidate human brain cell functions and interactions, but limitations in reproducibility, maturation and cell-type diversity persist. Especially, prolonged incorporation of mature microglia and studies of neuroinflammation have proven challenging. Here, we developed a human induced pluripotent stem cell-based three-dimensional cortical brain tissue model (3BTM) containing neurons, astrocytes and microglia with high reproducibility, maturity and viability. 3BTMs show morphological, functional and proteomic maturation of all cell types, leading to high similarity to their in vivo counterparts. Incorporated microglia survive for over 6 months and display mature morphology, functions and gene expression. Importantly, when engineered to model Alzheimer's disease pathology, 3BTMs recapitulate key disease hallmarks, including amyloid deposition, increased phospho-tau levels and neuroinflammation, with microglia shifting their transcriptional landscape to disease-relevant signatures. Treatment of Alzheimer's disease 3BTMs with anti-A&#x3b2; immunotherapy cleared deposits and largely reversed disease signatures in glia. Together, our microglia-containing model provides a platform for studying physiological and pathological states of human brain tissue.

Humans

Genetic evidence links hypertension to accelerated brain aging.

Hypertension affects one-third of adults and is a major comorbidity of neurocognitive disorders. The causal relationship, shared genetic architecture, and upstream mechanisms linking hypertension to brain aging remain unclear. Hypertension GWAS datasets from MVP and FinnGen R12 were meta-analyzed as the exposure, and a European-ancestry brain age gap (BAG) GWAS derived from the UK Biobank and LIFE-Adult cohorts was used as the outcome. MR and GSMR assessed causality. LDSC, HDL, and S-LDSC estimated genetic correlation. Four TWAS methods (MAGMA, FUSION, JTI-PrediXcan, FOCUS) mapped associations to genes, followed by SMR for causal validation and PoPS for prioritization. GSMAP with spatial transcriptomics characterized regional and cell-type enrichment. Hypertension and brain aging were genetically correlated, and MR and GSMR analyses suggested a causal effect of hypertension on increased brain age gap. TWAS identified 15 shared Hypertension-BAG genes, 10 supported by SMR. PoPS prioritized TRIM47 as the core gene. Shared signals were enriched in meninges, fiber tracts, cortical layer 1, and CA1 stratum lacunosum/radiatum, with cell-type enrichment in meninges, smooth muscle cells, oligodendrocytes, and astrocyte subtypes. Hypertension is genetically correlated with, and shows evidence of a causal effect on, accelerated brain aging. TRIM47 is a core gene bridging hypertension and BAG. GSMAP-based spatial enrichment provides a hypothesis-generating framework for understanding vascular, meningeal, and myelin-related pathways linking hypertension to increased brain age gap.

Humans

CRISPR-Enabled functional genomics in hPSCs-derived neural models for autism spectrum disorder.

Autism Spectrum Disorder (ASD) is a genetically heterogeneous neurodevelopmental condition in which hundreds of individually rare risk variants converge on a small number of shared biological pathways, including synaptic scaffolding, chromatin remodeling, excitation-inhibition balance, and cellular energy metabolism. Translating this genetic heterogeneity into mechanistic insight requires experimental systems capable of interrogating individual gene functions in human-relevant neural contexts at scale. CRISPR-enabled functional genomics in human pluripotent stem cell (hPSC)-derived neural models, spanning neural progenitors, cortical and inhibitory neurons, astrocytes, microglia, and brain organoids, provides precisely this capability. By integrating pooled perturbation screens with multimodal readouts including single-cell and spatial transcriptomics, chromatin accessibility profiling, proximity labeling proteomics, multi-electrode array electrophysiology, and metabolic flux analysis, these platforms enable systematic, causal mapping of ASD gene function at system resolution. Early applications have already revealed convergent mechanisms: BAF complex disruption expands the ventral progenitor pool and biases its fate toward oligodendrocyte and interneuron lineages; ADNP loss impairs microglial synaptic pruning through altered endocytic trafficking; and mTOR pathway dysregulation in PTEN- and TSC2-perturbed models links genetic risk directly to metabolic and mitochondrial dysfunction. Computational frameworks including MIMOSCA and SCEPTRE enable causal network reconstruction and pseudotime inference from these datasets, moving the field from gene lists toward pathway-level models of ASD pathobiology. Translational applications leverage isogenic iPSC panels and variant-level base and prime editing to stratify ASD variants by functional impact, informing gene therapy design for haploinsufficient targets such as CHD8 and SCN2A via AAV or antisense oligonucleotide delivery. Remaining challenges, including model developmental immaturity, batch variability, and the difficulty of modeling polygenic risk, are addressed by a roadmap integrating spatial perturbomics, AI-driven causal inference, and population-scale standardized biobanks. This review synthesizes the current state of CRISPR-based functional genomics in human stem cell neural models as a coherent experimental framework for converting ASD genetic associations into mechanistic understanding and therapeutic opportunity.

Humans

Experimental approaches for investigating sirtuin-mediated mitochondrial function, cellular metabolism, and epigenetic regulation.

Cellular pathways for experimental discovery provide a comprehensive overview of sirtuin biology and its critical involvement in HIV-associated neurocognitive disorders (HAND) and related neurodegenerative diseases, highlighting the translational potential of sirtuin-targeted therapeutic strategies. As NAD+-dependent deacetylases and ADP-ribosyl transferases, sirtuins regulate diverse cellular processes, including stem cell maintenance, cellular proliferation, metabolic homeostasis, apoptosis, autophagy, oxidative stress responses, and genomic stability, all of which contribute to neuronal dysfunction and disease progression. This chapter focuses on key mammalian sirtuins, including SIRT1 and SIRT2, which are primarily localized within the nucleus and cytosol; mitochondrial sirtuins SIRT3, SIRT4, and SIRT5; and nuclear/nucleolar sirtuins SIRT6 and SIRT7. Here, a method with a detailed protocol to isolate compartment-specific sirtuin expression and activity was used: subcellular fractionation was performed using a subcellular fractionation kit to obtain cytosolic and nuclear fractions, while mitochondrial isolation was carried out using Tom20 antibody-conjugated magnetic microbeads. These approaches were applied to brain tissues from HIV-positive individuals, as well as to HIV-Tat-treated human microglial (HMC3) cells and astrocytes. This experimental framework enables accurate assessment of compartment-resolved sirtuin regulation in disease-relevant models. Collectively, the chapter highlights the protective roles of sirtuins in mitigating key pathogenic mechanisms underlying HAND and related neurodegenerative diseases. These findings support the emerging concept that sirtuins represent promising pharmacological targets for the development of novel therapeutic interventions in neurodegeneration and HIV-associated brain disorders.

Humans

Leveraging functional annotations to map rare variants associated with Alzheimer disease with gruyere.

Increased availability of whole-genome sequencing (WGS) has facilitated the study of rare variants (RVs) in complex diseases. Multiple RV association tests are available to study the relationship between genotype and phenotype, but most do not fully leverage the availability of variant-level functional annotations. We propose genome-wide rare variant enrichment evaluation (gruyere), an empirical Bayesian framework that complements existing methods by learning global, trait-specific weights for functional annotations to improve variant prioritization. We apply gruyere to WGS data from the Alzheimer's Disease Sequencing Project to identify Alzheimer disease (AD)-associated genes and annotations. Growing evidence suggests that the disruption of microglial regulation is a key contributor to AD risk, yet existing methods have not examined rare non-coding effects that incorporate such cell-type-specific information. To address this gap, we (1) define per-gene non-coding RV test sets using predicted enhancer and promoter regions in microglia and other brain cell types (oligodendrocytes, astrocytes, and neurons) and (2) include cell-type-specific variant effect predictions (VEPs) as functional annotations. gruyere identifies 13 significant genetic associations not detected by other RV methods, four of which remain significant in omnibus tests. We find that deep-learning-based VEPs for splicing, transcription factor binding, and chromatin state are highly predictive of functional non-coding RVs. Our study establishes a robust framework incorporating functional annotations, coding RVs, and cell-type-associated non-coding RVs to perform genome-wide association tests, uncovering AD-relevant genes and annotations.

Alzheimer Disease

Drug resistance in breast cancer brain metastasis: mechanisms and therapeutic strategies.

Brain-metastatic breast cancer (BMBC) is a severe complication of advanced breast cancer, affecting 15-30% of metastatic patients, particularly those with HER2-positive or triple-negative subtypes, and is associated with dismal prognosis and median survival under 12&#xa0;months. Therapeutic resistance, driven by the central nervous system's sanctuary role, poses a major barrier to effective treatment, often resulting in discordant intracranial versus extracranial responses. This comprehensive review highlights BMBC resistance mechanisms, drawing from preclinical models, clinical studies, and genomic analyses. Key drivers include genetic/epigenetic alterations, BBB-mediated drug exclusion via efflux transporters, and microenvironmental interactions with astrocytes and immune cells that promote survival signaling. Additional factors encompass cancer stem cell plasticity/dormancy enabling therapy evasion, metabolic reprogramming and extracellular matrix remodeling that shields tumor from drugs. We highlight how these interconnected pathways create a protective niche for metastatic cells. Promising strategies to overcome resistance include BBB-penetrant agents, antibody-drug conjugates, nanomedicine, and combination therapies targeting the tumor microenvironment and epigenetics. By integrating mechanistic insights with translational opportunities, this review emphasizes the potential for personalized, multi-targeted approaches to improve patient outcomes in BMBC.

Humans

Single-nucleus transcriptomics reveals cell type-specific remodeling and epilepsy-associated microglia.

Temporal lobe epilepsy (TLE) is the most common acquired epilepsy, causing refractory seizures and cognitive deficits. We performed single-nucleus RNA sequencing on hippocampal tissue from mice 3 and 6 weeks following pilocarpine-induced status epilepticus, a robust model of TLE. Epilepsy samples showed reductions in Cck and Lamp5-Lhx6 interneuron subclusters, alongside increases in Cajal-Retzius cells, dentate granule (DG) cell precursors, and a mature DG cell subcluster. Among glia, an astrocyte subcluster and a markedly expanded microglia sublcuster were increased. We term this microglia population epilepsy-associated microglia (EAM). The transcriptomic profile of EAM overlaps with microglia described in models of Alzheimer's disease and traumatic brain injury, including enrichment of Myo1e and Igf1. EAM display amoeboid morphology, can be found in clumps around pyramidal and granule cell body layers, and exhibit enlarged vesicles and mitochondria. Cell-cell interaction analysis predicts DG cells as their primary interaction partners. This dataset defines transcriptomic programs underlying key cellular alterations in TLE, enabling mechanistic dissection of epileptogenesis.

TLE

Optimizing NGN2 Dosage Enhances the Neuronal Enrichment of iPSC-Derived Neuronal Cultures.

Proteomic analysis of highly neuron-enriched iPSC-derived cultures can provide valuable insights into the pathogenesis of neurological disease by minimizing confounding signals from non-neuronal populations. However, single-cell iPSC clones with stable NGN2 integration at the AAVS1 locus exhibit spontaneous loss of the mCherry reporter. In addition, following NGN2 induction, cultures frequently contain proliferative progenitor cells that compromise neuronal physical integrity. Here, we show that increased DNA methylation of the EF1-&#x3b1; promoter is associated with mCherry silencing. Importantly, reporter silencing does not affect iNeuron derivation, as evidenced by two lines of evidence. First, single-cell proteomic analysis indicated that mCherry silencing does not drive detectable proteomic divergence in undifferentiated iPSCs. Second, bulk proteomics and immunofluorescence analyses indicated that iPSC-derived neuronal cultures, whether expressing or lacking mCherry, resemble cortical glutamatergic neurons. Instead, the primary confounding factor in iNeuron generation was suboptimal neuronal conversion, which led to cell aggregates comprised of actively proliferating progenitor cells and astrocytes as the culture developed. We found that a 4-day period of NGN2 induction substantially increases neuronal maturation and the expression of neuronal-specific markers. Moreover, transient inhibition of Notch signaling is consistent with a reduction in progenitor cells. Finally, we observed that monoallelic NGN2 integration, rather than biallelic integration, preferentially increases expression of the CNS neuronal marker GPM6A over PNS markers (PRPH, POU4F1, ILS1).

Basic Helix-Loop-Helix Proteins

A single-cell meta-analysis evidences transposable element dysregulation in sex-based differences in Parkinson's disease.

Transposable elements (TEs) (mobile genetic elements comprising &#x223c;45% of the human genome) have recently emerged as potential contributors to Parkinson's disease (PD); however their role and sex-specific impact remain poorly understood. Here, we present the first integrative meta-analysis of TE expression across 4 substantia nigra single-nucleus RNA-seq datasets, comprising a total of 66 donors, generating a cell-type-resolved atlas of TE dysregulation in PD. We identified widespread TE activation across major brain cell types (i.e. neurons, astrocytes, oligodendrocytes and microglia), with marked upregulation of L1s in neurons and HERVs in oligodendrocytes. Sex-stratified analyses revealed distinct male- and female-biased TE signatures, indicating regulatory programs uniquely affected in each sex, including MIR elements in microglia and Alu subfamilies in neurons. Correlation and genomic proximity analyses also uncovered TE-gene associations linked to important PD pathways such as neuroinflammation or myelination. Collectively, our study positions TEs as potential sex-modulated contributors to PD pathology and also provides a public web resource (PATOSS) to explore PD-associated TE transcriptional deregulation.

Parkinson's disease

Blood phenylalanine lowering partially reverses white matter changes in a mouse model of phenylketonuria.

Phenylketonuria (PKU) is a genetic defect caused by lack of the liver enzyme phenylalanine hydroxylase (PAH). This deficiency results in elevated blood phenylalanine (Phe) levels and neurotoxicity, which is manifested by reduced brain size, lower neurotransmitter levels, and reduced myelination. The goal of this study was to investigate brain myelination defects and their reversibility upon blood Phe lowering by analyzing the corpus callosum (CC) of adult Pahenu2 (PAH-deficient) mice. MRI and immunostaining demonstrated a significant reduction in CC volume in Pahenu2 mice. Treatment with an adeno-associated vector (AAV) encoding mouse PAH for 3.5 months improved but did not completely normalize CC volume. Total cholesterol, a major component of myelin, was unchanged in the CC of Pahenu2 mouse, while some sterol intermediates were significantly reduced by treatment. Single-nuclei transcriptomics showed an upregulation of oxidative stress-related pathways and increased expression of transthyretin, ApoE, Cst3, and Cd81 in CC in Pahenu2 mice. Normalization of blood Phe restored gene expression to levels comparable to those of heterozygous mice and was associated with the generation of differentiated myelin-producing oligodendrocyte subtypes and neuroprotective astrocytes. In summary, Pahenu2 mice showed white matter abnormalities and changes in transcriptome and sterol profiles, which were partially corrected by the normalization of blood Phe.

Animals

AAV-mediated CBLN1 replacement rescues hereditary ataxia caused by bi-allelic CBLN1 variants.

Cbln1 is a secreted synaptic organizer required for parallel fiber-Purkinje cell (PF-PC) synapse integrity, climbing fiber (CF) refinement, and cerebellar motor learning but has not previously been implicated in human disease. We identified bi-allelic CBLN1 missense variants (A63P and Y112C) in two unrelated families with early-onset cerebellar ataxia accompanied by oculomotor abnormalities, cerebellar atrophy, and variable cognitive delay. In heterologous cells, both variants showed reduced steady-state protein abundance, impaired maturation through the early secretory pathway, and little or no detectable secretion, resulting in markedly reduced extracellular CBLN1 availability. Consistently, cerebellar granule cells expressing CBLN1-Y112C failed to induce excitatory synapses onto glutamate receptor &#x3b4;2 (GluD2)-expressing cells in vitro. A knockin mouse harboring Y112C lacked synaptic Cbln1 and recapitulated key features of Cbln1 deficiency, including disrupted PF-PC synapse organization, persistent CF multi-innervation, impaired PF-PC transmission, and long-term depression, and deficits in motor coordination and oculomotor learning. Notably, systemic delivery of an astrocyte-targeted adeno-associated virus expressing wild-type CBLN1 in adult mutant mice restored synaptic CBLN1 localization, cerebellar synaptic function, plasticity, and behavior. These findings establish CBLN1 deficiency as a cause of hereditary ataxia and identify extracellular CBLN1 replacement as a therapeutic strategy for a reversible cerebellar synaptopathy.

CBLN1

Putative glioblastoma origin-like cells in the subventricular zone: isolation and characterization.

Glioblastoma (GBM) remains lethal despite maximal therapy. The adult subventricular zone (SVZ), a neural stem-cell niche, has been implicated as a potential site of origin, yet the identity and functional properties of putative GBM origin-like cells (GBM-OCs) within the SVZ remain unclear. An SVZ-restricted somatic mutation mouse model (Cre-induced EGFRvIII expression with Trp53 and Pten disruption) was established and mouse SVZ-derived cells were prospectively isolated for functional and molecular profiling. Self-renewal, multipotency, invasive potential and tumour-initiating capacity were assessed relative to control SVZ cells and matched tumour-derived tumourspheres. Whole-genome and RNA sequencing defined genomic and transcriptional alterations during early progression. Mouse GBM-OCs exhibited self-renewal and multilineage differentiation and initiated tumours only after re-implantation into the SVZ (11/29, 38%), whereas direct striatal implantation failed (0/25, 0%), indicating context-dependent tumorigenic potential associated with the SVZ microenvironment. In contrast, tumour-derived tumourspheres retained tumorigenic capacity upon implantation into both the SVZ and the striatum. During progression from mouse GBM-OCs to tumours, whole-chromosome and arm-level aneuploidies accumulated. In patients with GBM, multi-region single-nucleus RNA sequencing of tumour-free SVZ, matched tumours and tumour-free cortex identified rare neural stem cell-like, astrocyte-like and oligodendrocyte precursor-like SVZ populations transcriptionally aligned with GBM programmes. These cells showed single-nucleus RNA-inferred chromosome 7 gain and/or chromosome 10 loss signals, with concordant low-frequency copy-number alterations in the SVZ detected by exome sequencing and enriched in matched tumours. Together, these findings support the presence of SVZ-resident stem or progenitor-like populations with early GBM-associated features, consistent with putative GBM-OCs, and highlight the SVZ niche as a potential target for early detection and niche-informed therapeutic strategies.

Animals

Genetic and epigenetic analysis of plasma glial fibrillary acidic protein (GFAP) levels in PTSD.

Glial fibrillary acidic protein (GFAP) is an astrocytic marker that can be assessed in blood using single molecule array technology. Recent studies suggest that individuals with posttraumatic stress disorder (PTSD) have suppressed circulating levels of this CNS biomarker. This study examined the hypothesis that PTSD and plasma GFAP levels share common genetic and epigenetic pathways. Using data from 1096 veterans and civilians, we computed a PTSD polygenic risk score (PRS) derived from a prior PTSD genomewide association study (GWAS) and found that PTSD severity and the PRS were each associated with reduced levels of GFAP. To clarify the basis of the PRS association, we performed a GWAS of GFAP which identified 20 genomewide-significant loci including genes implicated in independent GWASs of PTSD and neurodegenerative disease (e.g., PRKN, NFIA). Comparison of the PTSD and GFAP GWAS results showed that PTSD-associated genes were significantly enriched in the GFAP results with notable overlap involving NPSR1 and the protocadherin alpha (PCDHA) gene cluster. Similarly, we performed an epigenomewide association study (EWAS) of GFAP, which identified 4 genomewide-significant associations (including loci in MCT4 and SREBF1) and then compared those results to the findings of a PTSD EWAS. Results again showed significantly greater overlap than would be expected by chance and included loci implicated in prior studies of depression, dementia, and inflammation. This study clarifies the genetic and epigenetic basis of the association between PTSD and plasma GFAP levels and should encourage future research into the role of GFAP in the pathophysiology of PTSD.

Humans

Neuronal differentiation requires BRAT1 complex to remove REST from chromatin.

Repressor element-1 silencing transcription factor (REST) is required for the formation of mature neurons. REST dysregulation underlies a key mechanism of neurodegeneration associated with neurological disorders. However, the mechanisms leading to alterations of REST-mediated silencing of key neurogenesis genes are not known. Here, we show that BRCA1 Associated ATM Activator 1 (BRAT1), a gene linked to neurodegenerative diseases, is required for the activation of REST-responsive genes during neuronal differentiation. We find that INTS11 and INTS9 subunits of Integrator complex interact with BRAT1 as a distinct trimeric complex to activate critical neuronal genes during differentiation. BRAT1 depletion results in persistence of REST residence on critical neuronal genes disrupting the differentiation of NT2 cells into astrocytes and neuronal cells. We identified BRAT1 and INTS11 co-occupying the promoter region of these genes and pinpoint a role for BRAT1 in recruiting INTS11 to their promoters. Disease-causing mutations in BRAT1 diminish its association with INTS11/INTS9, linking the manifestation of disease phenotypes with a defect in transcriptional activation of key neuronal genes by BRAT1/INTS11/INTS9 complex. Finally, loss of Brat1 in mouse embryonic stem cells leads to a defect in neuronal differentiation assay. Importantly, while reconstitution with wild-type BRAT1 restores neuronal differentiation, the addition of a BRAT1 mutant is unable to associate with INTS11/INTS9 and fails to rescue the neuronal phenotype. Taken together, our study highlights the importance of BRAT1 association with INTS11 and INTS9 in the development of the nervous system.

Humans