Search PubMedSearch

SEARCH · Search PubMed

Results for “H3K27ac”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources

Histone H3K27ac spreads from enriched chromatin domains into neighboring regions upon loss of CTCF binding.

Acetylation of histone H3 at lysine 27 (H3K27ac) is enriched at enhancers and highly transcribed genes. Our previous study showed that an H3K27ac-enriched chromatin domain expanded into neighboring regions following the deletion of CTCF-binding motifs flanking the domain. In this study, we explored the spreading of H3K27ac on a genome-wide scale by analyzing its distribution around CTCF-binding sites in human K562 cells and examining changes upon CTCF loss. We found that a subset of CTCF-binding sites demarcates H3K27ac-enriched domains. Upon loss of CTCF binding, H3K27ac levels increased in most regions adjacent to these domains, indicating that H3K27ac can spread into neighboring chromatin. This spreading was accompanied by elevated transcription of nearby genes. Chromatin features, including histone modifications, CTCF-binding intensity, and CTCF-mediated chromatin interactions, were associated with the H3K27ac spreading. Notably, enhancers were more enriched within domains that exhibited H3K27ac spreading compared to those that did not, and the deletion of enhancers from the CTCF motif-deficient β-globin locus attenuated the spreading. These findings indicate that CTCF-binding sites serve as boundaries for H3K27ac-enriched domains and that, in the absence of CTCF binding, H3K27ac can spread into neighboring regions. H3K27ac spreading appears to be influenced by multiple chromatin features and to contribute to the transcriptional increase of nearby genes.

CTCF

Ovarian H3K27ac remodeling is associated with impaired follicular development in laying hens with fatty liver hemorrhagic syndrome.

Fatty liver hemorrhagic syndrome (FLHS) is a metabolic disease of laying hens that reduces egg production and is accompanied by reproductive impairment, but the ovarian regulatory mechanisms that connect nutritional stress to follicular dysfunction remain unclear. This study examined whether active chromatin remodeling in the ovary is associated with FLHS induced by a high-energy, low-protein (HELP) diet. Hy-Line Brown hens were assigned to a basal diet or HELP diet, and ovarian tissue was collected for histone H3 lysine 27 acetylation (H3K27ac) chromatin immunoprecipitation sequencing and RNA sequencing. The HELP diet reduced laying performance and the numbers of small yellow and hierarchical follicles, indicating compromised follicular development. Genome-wide H3K27ac profiling identified 2,111 regions with lower acetylation and 1,707 regions with higher acetylation in FLHS ovaries. Genes linked to differential H3K27ac regions were enriched in pathways related to oocyte meiosis, cell cycle control, FoxO signaling, gonadotropin-releasing hormone signaling, and steroid hormone biosynthesis. RNA sequencing identified 341 differentially expressed genes, with a predominance of downregulated genes. Integration of chromatin and transcriptome data highlighted folliculogenesis-related genes, including FGF1, FGF9, and MMP10, that showed reduced H3K27ac enrichment together with decreased expression. Super-enhancer analysis further identified 131 regions with reduced H3K27ac signal in FLHS ovaries, including regions located near PCNA and RAP1A, two genes involved in cellular proliferation and survival signaling. Motif enrichment of differential H3K27ac regions implicated Fos, SF-1/NR5A1, and GATA-4 as candidate transcriptional regulators. These findings indicate that HELP diet-induced FLHS is associated with broad attenuation of active ovarian regulatory elements and reduced expression of genes required for follicle growth, tissue remodeling, and steroidogenic function. The study provides an ovarian epigenomic framework for understanding reproductive decline in FLHS-affected laying hens.

Fatty liver hemorrhagic syndrome

Machine learning on multiple epigenetic features reveals H3K27Ac as a driver of gene expression prediction across patients with glioblastoma.

Epigenetic mechanisms play a crucial role in driving transcript expression and shaping the phenotypic plasticity of glioblastoma stem cells (GSCs), contributing to tumor heterogeneity and therapeutic resistance. These mechanisms dynamically regulate the expression of key oncogenic and stemness-associated genes, enabling GSCs to adapt to environmental cues and evade targeted therapies. Importantly, epigenetic reprogramming allows GSCs to transition between cellular states, including therapy-resistant mesenchymal-like phenotypes, underscoring the need for epigenetic-targeting strategies to disrupt these adaptive processes. Understanding these epigenetic drivers of gene expression provides a foundation for novel therapeutic interventions aimed at eradicating GSCs and improving glioblastoma outcomes. Using machine learning (ML), we employ cross-patient prediction of transcript expression in GSCs by combining epigenetic features from various sources, including ATAC-seq, CTCF ChIP-seq, RNAPII ChIP-seq, H3K27Ac ChIP-seq, and RNA-seq. We investigate different ML and deep learning (DL) models for this task and ultimately build our final pipeline using XGBoost. The model trained on one patient generalizes to other 11 patients with high performance. Notably, H3K27Ac alone from a single patient is sufficient to predict gene expression in all 11 patients. Furthermore, the distribution of H3K27Ac peaks across the genomes of all patients is remarkably similar. These findings suggest that GSCs share a common distributional pattern of enhancer activity characterized by H3K27Ac, which can be utilized to predict gene expression in GSCs across patients. In summary, while GSCs are known for their transcriptomic and phenotypic heterogeneity, we propose that they share a common epigenetic pattern of enhancer activation that defines their underlying transcriptomic expression pattern. This pattern can predict gene expression across patient samples, providing valuable insights into the biology of GSCs.

Glioblastoma

Altered histone modifications in Aedes aegypti following Rift Valley fever virus exposure.

When arthropod-borne viruses (arboviruses) are delivered to vector mosquitoes in an infectious bloodmeal, viral components interact with host proteins to hijack cells and initiate replication. The extent to which arbovirus infection alters mosquito host transcriptional and genomic regulatory processes is currently unknown. We hypothesized that histone modifications would be altered in mosquitoes exposed to Rift Valley fever virus (RVFV MP12, Phlebovirus riftense, family Phleboviridae). We interrogated transcriptome and chromatin landscapes in Aedes aegypti midguts by performing Cleavage Under Targets and Release Using Nuclease (CUT&RUN), using H3K27ac and H3K9me3 marks. Altered H3K27ac marks were identified following RVFV MP12 exposure, as well as upon bloodfeeding alone. It took several days for differential H3K27ac marks to be associated with differentially expressed genes (DEGs) in RVFV-exposed midguts. H3K27ac peaks showed progressive depletion as infection progressed. Gene set enrichment analysis revealed that immune response transcripts were enriched at 1 and 3 dpf (days post-feeding) but depleted by 7 dpf. Hedgehog/Gli (glioma-associated oncogene homolog) signaling pathway transcripts were depleted, indicating possible viral manipulation of cellular polarization. Moreover, at 7 dpf, 7 of 102 DEGs were proximal to differentially acetylated sites in a pattern expected to favor viral propagation. However, one transcript coding for an antiviral effector (LysM-TLDc domain protein) showed significant depletion of both H3K9me3 and H3K27ac marks. Analysis of midguts after a non-infectious bloodmeal versus sugar-fed controls revealed global changes to H3K27ac and H3K9me3 marks during and following the period of bloodmeal digestion. Differential H3K27ac marks were proximal to one quarter of all DEGs at 1 dpf, consistent with an important role of H3K27ac in bloodmeal digestion. These results demonstrate that H3K27ac and H3K9me3 patterns are altered upon virus exposure in a complex interplay that favors viral replication but is also countered by host responses to limit replication.

ChIP-Seq

Hormetic nutrient stress promotes longevity by orchestrating histone acetylation on key lipid catabolism and antioxidant defense genes.

Exposure to low levels of environmental challenges, known as hormetic stress, such as nutrient deprivation and heat shock, fosters subsequent stress resistance and promotes healthy aging in later life. However, specific mechanisms governing transcriptional reprogramming upon hormetic nutrient stress remain elusive. In this study, we identified histone H3 lysine 27 acetylation (H3K27ac) as a crucial driver of transcriptomic adaptation to hormetic fasting. Beyond its immediate function of enhancing lipid catabolism for alternative energy sources, stress-induced H3K27ac activates lifelong antioxidant defenses, thereby reducing reactive oxygen species (ROS) produced by stress-induced fatty acid oxidation and their accumulation during aging. The increase in H3K27ac, mediated by pioneer factor PHA-4/FOXA and cooperating transcription factor NHR-49/HNF4, is crucial for lifespan extension under hermetic nutrient stress in Caenorhabditis elegans. Our findings establish H3K27ac as a key transcriptional switch that bridges nutrient status with transcriptomic reprogramming, underpinning the pro-longevity effects of hormetic fasting through orchestrating lipid catabolism and antioxidative defenses.

Journal Article

Exposure to zinc oxide nanoparticles inhibits preimplantation embryonic development by disrupting zygotic genome activation.

The potential adverse effects of zinc oxide nanoparticles (ZnONPs) on human reproductive health may arise from their increasing industrial and commercial applications. However, their effects on preimplantation embryonic development and the related molecular mechanisms are still not well understood. Here, we demonstrate that ZnONPs exposure exhibit toxicity to a critical developmental period in mice. We observed that sustained exposure to ZnONPs in vitro resulted in embryonic development arrest at the 2-cell stage. To identify the susceptible stage, we controlled experiments to treat embryos with ZnONPs in the different processes of early embryonic development and determined that ZnONPs mainly to affect 2-cell stage embryos. According to the RNA-seq and EU (5-ethynyl uridine) analysis, the transcriptional activity of minor ZGA genes increased in the late 2-cell embryos following ZnONPs exposure. Subsequently, we employed multi-omics assays, including CUT&Tag and ATAC-seq. We found that ZnONPs exposure led to increased enrichment of H3K27ac (Histone H3 acetylated lysine 27) in late 2-cell embryos and enhanced chromatin accessibility, which led to abnormal upregulation of minor zygotic genome activation (ZGA) genes. In addition, the direct occupancy of ZnONPs at H3K27ac modification sites was verified through pulldown and immunoprecipitation. In conclusion, our findings demonstrate that ZnONPs exposure disrupting minor ZGA by interfering with H3K27ac erasure on the embryonic genome and ultimately impairing the developmental potential of embryos.

Animals

Enhancer and super-enhancer landscape in polycystic kidney disease.

Widespread aberrant gene expression is a pathological hallmark of polycystic kidney disease (PKD). Numerous pathogenic signaling cascades, including c-Myc, Fos, and Jun, are transactivated. However, the underlying epigenetic regulators are poorly defined. Here we show that H3K27ac, an acetylated modification of DNA packing protein histone H3 that marks active enhancers, is elevated in mouse and human samples of autosomal dominant PKD. Using comparative H3K27ac ChIP-Seq analysis, we mapped over 16000 active intronic and intergenic enhancer elements in Pkd1-mutant mouse kidneys. We found that the cystic kidney epigenetic landscape resembles that of a developing kidney, and over 90% of upregulated genes in Pkd1-mutant kidneys are co-housed with activated enhancers in the same topologically associated domains. Furthermore, we identified an evolutionarily conserved enhancer cluster downstream of the c-Myc gene and super-enhancers flanking both Jun and Fos loci in mouse and human models of autosomal dominant PKD. Deleting these regulatory elements reduced c-Myc, Jun, or Fos abundance and suppressed proliferation and 3D cyst growth of Pkd1-mutant cells. Finally, inhibiting glycolysis and glutaminolysis or activating Ppara in Pkd1-mutant cells lowerd global H3K27ac levels and its abundance on c-Myc enhancers. Thus, our work suggests that epigenetic rewiring mediates the transcriptomic dysregulation in PKD, and the regulatory elements can be targeted to slow cyst growth.

Animals

Crosstalk between epitranscriptomic and epigenomic modifications and its implication in human diseases.

Crosstalk between N6-methyladenosine (m6A) and epigenomes is crucial for gene regulation, but its regulatory directionality and disease significance remain unclear. Here, we utilize quantitative trait loci (QTLs) as genetic instruments to delineate directional maps of crosstalk between m6A and two epigenomic traits, DNA methylation (DNAme) and H3K27ac. We identify 47 m6A-to-H3K27ac and 4,733 m6A-to-DNAme and, in the reverse direction, 106 H3K27ac-to-m6A and 61,775 DNAme-to-m6A regulatory loci, with differential genomic location preference observed for different regulatory directions. Integrating these maps with complex diseases, we prioritize 20 genome-wide association study (GWAS) loci for neuroticism, depression, and narcolepsy in brain; 1,767 variants for asthma and expiratory flow traits in lung; and 249 for coronary artery disease, blood pressure, and pulse rate in muscle. This study establishes disease regulatory paths, such as rs3768410-DNAme-m6A-asthma and rs56104944-m6A-DNAme-hypertension, uncovering locus-specific crosstalk between m6A and epigenomic layers and offering insights into regulatory circuits underlying human diseases.

Humans

Deciphering estrogen receptor alpha-driven transcription in human endometrial stromal cells via transcriptome, cistrome, and integration with chromatin landscape.

OBJECTIVE: To investigate estrogen receptor gene 1 (ESR1) and estrogen-driven transcription in human endometrial stromal cells. DESIGN: RNA sequencing (RNA-seq) and Cleavage Under Targets and Release Using Nuclease (Cut&Run) were performed on telomerase-immortalized human endometrial stromal cells with Clustered Regularly Interspaced Short Palindromic Repeats-mediated ESR1 activation. Hi-C-based chromatin architecture analysis (H3K27ac HiChIP) was conducted in primary endometrial stromal cells. SUBJECTS: Biopsies from two healthy, reproductive-aged volunteers with regular menstrual cycles and no history of gynecological malignancies. EXPOSURE: The ESR1-activated and control endometrial stromal cells were treated with estradiol (E2) or vehicle. Primary endometrial stromal cells were treated with vehicle or a decidualization cocktail. MAIN OUTCOME MEASURES: Differential gene expression analysis (RNA-seq) identified ligand-independent and -dependent ESR1 activity. Cut&Run profiled ESR1 genomic binding in ESR1-activated cells. H3K27ac HiChIP mapped hormone-induced changes in chromatin looping in primary cells. RESULTS: Among seven tested guide RNAs (gRNA), the ESR1-3 gRNA induced robust ESR1 activation and restored E2 responsiveness. Bulk RNA-seq revealed both ligand-dependent and -independent ESR1 transcriptional programs regulating inflammation, proliferation, and cancer-related pathways. Notably, 72% of differentially expressed genes overlapped with genes active in human endometrial tissue during the proliferative estrogen-dominant phase, supporting their physiological relevance. The Cut&Run-seq identified genome-wide ESR1 binding sites, with most binding sites located at distal regulatory elements. Integration of Cut&Run data with H3K27ac HiChIP chromatin loops linked distal ESR1 binding sites to gene promoters, including genes involved in decidualization (e.g., FOXO1) and endometrial cancer (e.g., ERRFI1, NRIP1, and EPAS1). Functional assays showed that ESR1 promotes cell viability and, in the presence of E2, enhances migration. CONCLUSION: The CRISPR-mediated ESR1 activation restores estrogen responsiveness in endometrial stromal cells. Combined transcriptomic, cistromic, and chromatin architecture analyses reveal ESR1's role in regulating decidualization and inflammation-related gene networks, with relevance to endometrial pathologies including endometrial cancer. This model serves as a powerful tool to study estrogen signaling in endometrial stromal cell biology and related pathologies.

Humans

Multiomics Reveal Associations Between CpG Methylation, Histone Modifications and Transcription in a Species That has Lost DNMT3, the Colorado Potato Beetle.

Insects display exceptional phenotypic plasticity, which can be mediated by epigenetic modifications, including CpG methylation and histone modifications. In vertebrates, both are interlinked and CpG methylation is associated with gene repression. However, little is known about these regulatory systems in invertebrates, where CpG methylation is mainly restricted to gene bodies of transcriptionally active genes. A widely conserved mechanism involves the co-transcriptional deposition of H3K36 trimethylation and the targeted methylation of unmethylated CpGs by the de novo DNA methyltransferase DNMT3. However, DNMT3 has been lost multiple times in invertebrate lineages raising the question of how the links between CpG methylation, histone modifications and gene expression are affected by its loss. Here, we report the epigenetic landscape of Leptinotarsa decemlineata, a beetle species that has lost DNMT3 but retained CpG methylation. We combine RNA-seq, enzymatic methyl-seq and CUT&Tag to study gene expression, CpG methylation and patterns of H3K36me3 and H3K27ac histone modifications on a genome-wide scale. Despite the loss of DNMT3, H3K36me3 mirrors CpG methylation patterns. Together, they give rise to signature profiles for expressed and not expressed genes. H3K27ac patterns show a prominent peak at the transcription start site that is predictive of expressed genes irrespective of their methylation status. Our study provides new insights into the evolutionary flexibility of epigenetic modification systems that urge caution when generalizing across species.

Animals

Redistribution of super-enhancers promotes malignancy in human hepatocellular carcinoma.

INTRODUCTION: Super-enhancers (SEs) are defined as the regulatory region where intensive transcriptional cofactors bind. Dysregulation of SEs is related to multiple diseases, however, its role in hepatocellular carcinoma (HCC) remains elusive. OBJECTIVES: This work aimed to reveal the dysregulation of SEs in HCC and the therapeutic potential for HCC treatment. METHODS: Fifteen HCC and twelve paracancerous samples underwent chromatin immunoprecipitation (ChIP) sequencing targeting H3K27ac, and subsequently the SEs were identified by the Rank Ordering of Super-Enhancers algorithm. Differential SEs featured by tumor or paracancerous tissues were identified, and cross-referenced with the differential expression genes and prognosis-related genes in 2 independent public or in-house HCC cohorts. The SE region of HSPA4 was deleted in the genome of HCCLM3 cell by CRISPR-Cas9, named HSPA4-SE-KO cells. The potential druggable transcriptional factors were identified by CRCmapper, GeneMANIA and Drug Gene Interaction Database (DGID). RESULTS: Five targets, including CDKN2C, HSPA4, GGH, PDGFA, and CAP2, were identified as HCC-gain SEs with oncogenic potential, which were further validated experimentally by SE inhibitors and ChIP targeting H3K27ac and BRD4. Cell proliferation and migration assays further confirmed that silencing of these HCC-gain SEs significantly suppressed the malignant phenotype of HCC cell lines. HSPA4 appeared strongest oncogenic functions among these targets, which was further verified by HCC mouse xenograft models and clinical sample investigation. Moreover, HSPA4-SE-KO cells obtained significantly suppressed HSPA4 expression and retarded tumorigenic capability. Finally, dysregulation of transcriptional factors engaged in the oncogenic role of SEs, and Danthron that targeting RXRA were identified from DGID for HCC treatment. CONCLUSION: The dysregulated SE landscape of HCC promoted the malignancy phenotype by the upregulation of oncogenes, and SE-regulatory network might be potential drug targets for HCC treatment. Our study deepened the insight of epigenetic dysregulation in HCC, offering the groundwork for SEs as potential therapeutic targets of HCC treatment.

Humans

Dual EZH1/2 inhibition enhances DNMT inhibitor efficacy in colon cancer through targeting H3K27me1.

Our recent work showed that low-dose DNMT inhibitor (DNMTi) treatment sensitizes colon cancer cells to EZH2 inhibitors (EZH2i), synergistically upregulating tumor suppressor genes (TSGs) and transposable elements through activation of the calcium-calcineurin-NFAT signaling pathway. A key observation was that EZH2i displayed variable sensitivities in combination therapy, which could not be explained solely by loss of lysine 27 trimethylation on histone H3 (H3K27me3), the most commonly studied EZH2 product. This led us to perform a comprehensive pharmacologic screen of Polycomb Repressive Complex 2 (PRC2) antagonists. Here, we show that compounds targeting both EZH2 and its interchangeable catalytic subunit, EZH1, achieved superior TSG re-expression when combined with DNMTi. Integrative proteomic and epigenomic analyses revealed that EZH1/2 inhibitors reduce all three H3K27 methylation states, whereas EZH2-selective inhibitors preserve EZH1-dependent H3K27me1 at deeply Polycomb-repressed genomic regions. Notably, H3K27me1 loss coincided with deposition of p300/CBP-dependent lysine 27 acetylation on histone H3 (H3K27ac), which proved essential for TSG re-expression. Paradoxically, blocking p300/CBP activity further enhanced the growth-inhibitory effects of combined DNMT and EZH1/2 inhibition. Mechanistically, we show that EZH1/2 inhibition redistributes p300/CBP activity, reducing H3K27ac from oncogenic loci and redirecting it to bivalent regions that enable TSG re-expression. Collectively, these findings reveal a coordinated role for EZH1-dependent H3K27me1 and DNA methylation in sustaining oncogenic transcriptional programs and provide strong rationale for advancing dual EZH1/2 inhibitors for combination epigenetic cancer therapy.

DNA methylation

MLL4 protects cardiomyocytes against ischemia-reperfusion injury through STAT3-mediated mitochondrial function.

Myocardial ischemia-reperfusion injury (MIRI) is an inevitable pathophysiological response during the revascularization process following myocardial ischemia. Despite its clinical significance, effective targeted therapies for MIRI remain an unmet medical need. Mixed-lineage leukemia 4 (MLL4), a member of the SET family of histone methyltransferases, exhibits particular methyltransferase action toward histone H3 lysine 4 (H3K4). This study establishes a protective role for MLL4 in MIRI pathogenesis. Utilizing cardiomyocyte-specific Mll4 knockout mice and an in vivo ischemia-reperfusion (I/R) model induced by left anterior descending coronary artery ligation, we observed significant upregulation of MLL4 expression in cardiac tissue following I/R. Genetic ablation of Mll4 in cardiomyocytes markedly exacerbated both acute and chronic phases of MIRI. In vitro, Mll4 knockdown in neonatal rat cardiomyocytes (NRCMs) amplified mitochondrial dysfunction and apoptosis under hypoxia/reoxygenation (H/R) conditions. Integrated analysis of Cleavage Under Targets and Tagmentation sequencing (CUT&Tag-seq) and RNA sequencing (RNA-seq) revealed that Mll4 deficiency induces a pronounced reduction in H3K4 monomethylation (H3K4me1) and histone H3 lysine 27 acetylation (H3K27ac) enrichment at the Stat3 genomic locus. Mechanistically, MLL4 functions as a transcriptional activator of Stat3 by depositing H3K4me1 and H3K27ac, thereby facilitating STAT3 transcription. This regulatory cascade ultimately governs STAT3-dependent mitochondrial homeostasis. Collectively, these findings identify MLL4 as a critical epigenetic regulator of MIRI and suggest its therapeutic targeting may offer a promising strategy for mitigating reperfusion injury.

Animals

Multi-omics Approaches to CCAAT/Enhancer-Binding Protein Beta in Oral Squamous Cell Carcinoma: Crosstalk Between Tumor Cells and Tumor-Associated Macrophages Driving Disease Progression.

BACKGROUND: CCAAT/Enhancer-Binding Protein Beta (CEBPB) is an important transcription factor that regulates tumor progression. However, the mechanism by which CEBPB regulates the progression of Oral Squamous Cell Carcinoma (OSCC) remains incompletely understood. Tumor progression depends on complex intercellular interactions within the tumor microenvironment. The purpose of this study was to investigate the role and epigenetic regulatory mechanisms of CEBPB in interactions between OSCC cells and tumor-infiltrating immune cells. METHODS: Bulk RNA-seq, ChIP-seq, and scRNA-seq data were obtained from The Cancer Genome Atlas (TCGA) database and the Gene Expression Omnibus (GEO) database. The HOMER algorithm was employed to identify enhancers and predict the CEBPB-binding motif. Cell cluster analysis, functional enrichment, and intercellular interaction analysis were performed using the "Seurat" R package. H3K27ac enrichment at GAS6 enhancers was validated by ChIP-qPCR. Metastatic OSCC cells with CEBPB knockdown or GAS6 overexpression were established and co-cultured with THP-1 cells. IL-10 and IL-6 secretion from co-cultured THP-1 cells was detected via ELISA. Chemotaxis of OSCC cells toward THP-1 cells was assessed through a Transwell assay. RESULTS: CEBPB was upregulated in OSCC and correlated with poor prognosis. By integrating H3K27ac ChIP-seq and bulk RNA-seq data, 131 CEBPB-regulated enhancer-controlled genes were identified in lymph node metastatic OSCC cells. scRNA-seq analysis revealed eight major cell clusters in primary foci and lymph node metastases, including T/NK cells, malignant epithelial cells, B/plasma cells, macrophages, fibroblasts, dendritic cells, endothelial cells, and mast cells, with the malignant epithelial cells stratified into distinct sub-clusters. CEBPB expression was elevated in malignant epithelial cells of lymph node metastases compared to primary foci. Furthermore, 15 pairs of enhanced ligand-receptor interactions were identified in lymph node metastases relative to primary foci. GAS6 was a CEBPB-regulated enhancer-controlled gene, primarily mediating interactions between malignant cells and macrophages. CEBPB knockdown in metastatic OSCC cells significantly impaired their chemotaxis toward cocultured THP-1 cells, and downregulated IL-10/IL-6 secretion and CD206 expression in cocultured THP-1 cells. Conversely, GAS6 overexpression reversed these inhibitory effects. CONCLUSION: CEBPB activated GAS6 transcription in metastatic OSCC cells. The CEBPB/ GAS6 axis in metastatic OSCC cells enhanced their chemotaxis toward macrophages and promoted the M2 polarization of macrophages, thereby facilitating the establishment of an immunosuppressive microenvironment.

Humans

Integrative Genomic, Transcriptomic and Epigenomic Analysis Reveals cis-regulatory Contributions to High-altitude Adaptation in Tibetan Pigs.

The Qinghai-Tibet Plateau, characterized by its extreme environmental conditions, presents significant challenges to life, making it an ideal region for studying adaptation and evolution. Tibetan pigs, known for their high genetic diversity and exceptional adaptability to high altitudes, serve as excellent models for investigating high-altitude adaptation. While previous studies have extensively identified genetic determinants associated with high-altitude adaptation, the molecular mechanisms, particularly cis-regulatory patterns, remain poorly understood. Here, we conducted a selective sweep analysis using 484 genomes from Chinese and Western pig breeds across various altitudes, revealing 38.56 Mb of genomic regions under selection in Tibetan pigs. Enrichment analysis identified the lung as the primary functional tissue involved in high-altitude adaptation, supported by tissue-specific transcriptional and regulatory patterns observed between Tibetan and Meishan pigs (low altitude). By integrating genomic, RNA-seq, ATAC-seq, and H3K27ac HiChIP data, we constructed comprehensive enhancer-promoter regulatory maps of candidate genes and pinpointed promising genetic determinants associated with high-altitude adaptation, including SNPs in EPAS1, KLF13, SPRED1, and CFD. These loci were predicted to influence chromatin accessibility and the interactions of regulatory elements, with altered binding strength of relevant transcription factors. Further in vitro experiments confirmed that these loci function as allele-specific enhancers, modulating the expression of target genes. Our findings elucidate the regulatory basis of high-altitude adaptation in Tibetan pigs and provide valuable insights for exploring hypoxia-related diseases in livestock and humans.

Animals

Stem Cell Differentiation Disperses Transcriptional Clusters via a Conserved Surface-Condensate Trajectory.

Stem cells exhibit exceptionally prominent transcriptional clusters, which dissolve with progressing differentiation. Although these clusters are assigned central roles in embryonic gene regulation, their formation and loss during differentiation remain poorly understood. This study reveals that these prominent clusters disperse along a conserved trajectory in mouse embryonic stem cells, fruit fly testes, and zebrafish embryos. Imaging and lattice simulations show that these clusters form via surface condensation on H3K27ac-marked super-enhancer regions, which act as genomic scaffolds. Upon differentiation, partial loss of these active epigenetic marks and transcription-driven unfolding lead to dispersal of the prominent clusters. The block copolymer-based lattice simulations explain this process as a conserved trajectory through a three-dimensional state space, governed by surface condensation principles that extend beyond canonical liquid-liquid phase separation. This work marks surface condensation as a biophysical mechanism for the dynamic organization of stem cell-specific transcriptional hubs and demonstrates evolutionary conservation in several organisms. By uncovering a conserved biophysical mechanism for transcriptional organization in development, our work illustrates how polymer properties can contribute to the control of cell identity and fate.

Animals

NAD+ Metabolism Licenses Zygotic Genome Activation via PARP7-Mediated ADP-Ribosylation of UHRF1 in Mouse Early Embryos.

Zygotic genome activation (ZGA) is a critical developmental milestone whose metabolic regulation remains unclear. This study identifies a pivotal role for Nicotinamide adenine dinucleotide (NAD+) metabolism in regulating ZGA through poly(ADP‑ribose) polymerase 7(PARP7)-mediated ADP-ribosylation. Using ultra-low input embryo metabolomics, we profiled metabolism from zygote to blastocyst, revealing a significant NAD+ decline at the 2-cell stage. This shift coincided with specific upregulation of the mono-ADP-ribosyltransferase PARP7, confirmed by transcriptomics, quantitative RT-PCR, western blot, and immunofluorescence. Genetic knockdown via trim-away technology or pharmacological inhibition with RBN-2397 caused developmental delay/arrest at the 2-cell stage, impaired blastocyst formation, and defective ZGA. Mechanistically, PARP7 deficiency reduced chromatin accessibility (ATAC-seq), diminished H3K4ac and H3K27ac marks, and impaired RNA polymerase II transcription. Integrated proteomics and ADP-ribosylome analysis of late 2-cell embryos identified UHRF1 as a key PARP7 target, mono-ADP-ribosylated at lysines K30 and K31. This modification stabilized UHRF1 protein (cycloheximide chase), and UHRF1 overexpression partially rescued the transcriptional defects associated with ZGA from PARP7 inhibition. Our findings establish a metabolic-epigenetic axis wherein NAD+ metabolism, via PARP7-mediated ADP-ribosylation of UHRF1, regulates chromatin remodeling and transcriptional activation during ZGA, offering fundamental insights into early development.

Animals

Prenatal Androgenization Modifies H3K9me3 Binding in the Promoter of the Androgen Receptor Gene in the Arcuate Nucleus of the Adult Female Mouse.

Animal models have shown that prenatal exposure to excess androgens is associated with the development of polycystic ovary syndrome (PCOS) features. We have identified that prenatally androgenized (PNA) mice modelling PCOS show suppressed androgen receptor mRNA (Ar) expression in the arcuate nucleus (ARC) across development. This could contribute to PCOS-related impaired gonadal steroid hormone feedback to GnRH neurons. However, the mechanism of Ar mRNA suppression following PNA is not determined. We performed a chromatin immunoprecipitation (ChIP) assay coupled with quantitative PCR (qPCR) to investigate histone and transcription factor binding within the Ar gene promoter or enhancer regions in the ARC of female mice at postnatal day (P)60 or gestational day (GD)18.5. In comparison to adult vehicle control (VEH) mice, our ChIP-qPCR revealed that H3K9me3, a repressive histone mark, was increased in adult PNA mice at the promoter regions of the Ar gene. H3K27ac, an active histone mark, and SP1, a transcription factor that acts as a positive regulator of gene expression, were unchanged in the same regions. Increased H3K9me3 seen at the promoter region in adult PNA mice, however, was not observed in the GD18.5 mice ARC following PNA. These results suggest that the deposition of H3K9me3 on the Ar promoter is unlikely to be established by PNA at the time of excess androgen exposure, and instead is likely to be established later in postnatal development or in adulthood. These data provide greater understanding of the developmental mechanisms and timeline underpinning PNA-mediated female dysfunction and PCOS-like reproductive physiology.

Animals