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Directed differentiation of mouse embryonic stem cells (mESCs) or induced pluripotent stem cells (iPSCs) provides powerful models to dissect the molecular mechanisms leading to the formation of specific cell lineages. Treatment with histone deacetylase inhibitors can significantly enhance the efficiency of directed differentiation. However, the mechanisms are not well understood. Here, we use CUT&RUN in combination with ATAC-seq to determine changes in both histone modifications and genome-wide chromatin accessibility following valproic acid (VPA) exposure. VPA induced a significant increase in global histone H3 acetylation (H3K56ac), a core histone modification affecting nucleosome stability, as well as enrichment at loci associated with cytoskeletal organization and cellular morphogenesis. In addition, VPA altered the levels of linker histone H1 subtypes and the total histone H1/nucleosome ratio indicative of initial differentiation events. Notably, ATAC-seq analysis revealed changes in chromatin accessibility of genes involved in regulation of CDK serine/threonine kinase activity and DNA duplex unwinding. Importantly, changes in chromatin accessibility were evident at several key genomic loci, such as the pluripotency factor Lefty, cardiac muscle troponin Tnnt2, and the homeodomain factor Hopx, which play critical roles in cardiomyocyte differentiation. Massive parallel transcription factor (TF) footprinting also indicates an increased occupancy of TFs involved in differentiation toward mesoderm and endoderm lineages and a loss of footprints of POU5F1/SOX2 pluripotency factors following VPA treatment. Our results provide the first genome-wide analysis of the chromatin landscape following VPA-induced differentiation in mESCs and provide new mechanistic insight into the intricate molecular processes that govern departure from pluripotency and early lineage commitment.
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http://dx.doi.org/10.1186/s13072-021-00432-5 | DOI Listing |
New Phytol
September 2025
National Key Laboratory of Crop Genetic Improvement, National Engineering Research Center of Rapeseed, Hubei Hongshan Laboratory, Huazhong Agricultural University, Wuhan, 430070, China.
Heterosis holds great potential for improving yield, quality, and environmental adaptability in crop breeding, which suggests that hybrids can exhibit better performance in adapting to extreme environments. However, the epigenetic mechanisms of salt-tolerant heterosis in allopolyploid crop Brassica napus (AACC, 2n = 38), particularly chromatin accessibility, remain largely unexplored. We investigated the dynamics of chromatin accessibility and transcriptional reprogramming during a time course of salt exposure in Brassica napus hybridization.
View Article and Find Full Text PDFCell Rep
September 2025
Laboratory of Molecular Neurobiology, Nencki Institute of Experimental Biology Polish Academy of Sciences, Pasteur St. 3, Warsaw 02-093, Poland; Laboratory of Tumour Hypoxia and Epigenomics, Nencki Institute of Experimental Biology Polish Academy of Sciences, Pasteur St. 3, Warsaw 02-093, Poland. El
Hypoxia is a key histopathological feature of glioblastoma, associated with tumor aggressiveness and therapy resistance. Glioma-associated microglia and macrophages (GAMs) are key players in the tumor microenvironment of glioblastoma and acquire immunosuppressive properties during tumor progression. We show that hypoxia alters key GAM identity genes, as it upregulates the expression of monocytic marker lectin galactoside-binding doluble 3 (Lgals3) and downregulates the homeostatic microglial markers purinergic receptor P2Y G-protein coupled 12 (P2ry12) and transmembrane protein 119 (Tmem119) in GAMs co-cultured with glioma cells and in glioblastoma patients' samples.
View Article and Find Full Text PDFJ Assoc Res Otolaryngol
September 2025
Department of Anesthesiology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA.
Purpose: The mammalian cochlea has two types of low abundance and highly specialized inner (IHC) and outer (OHC) mechanosensory hair cells. Their malfunction or death is a common cause of congenital and acquired deafness. IHCs and OHCs exhibit different transcriptomes during development.
View Article and Find Full Text PDFTo uncover molecular determinants of motor neuron degeneration and selective vulnerability in amyotrophic lateral sclerosis (ALS), we generated longitudinal single-nucleus transcriptomes and chromatin accessibility profiles of spinal motor neurons from the SOD1-G93A ALS mouse model. Vulnerable alpha motor neurons showed thousands of molecular changes, marking a transition into a novel cell state we named 'disease-associated motor neurons' (DAMNs). We identified transcription factor regulatory networks that govern how healthy cells transition into DAMNs as well as those linked to vulnerable and resistant motor neuron subtypes.
View Article and Find Full Text PDFThe spatial organization and dynamics of a genome are central to gene regulation. While a comprehensive understanding of chromatin organization in the human nucleus has been achieved using fixed-cell methods, measuring the dynamics of specific genomic regions over extended periods in individual living cells remains challenging. Here, we present a robust and fully genetically encoded system for fluorescent labeling and long-term tracking of any accessible non-repetitive genomic locus in live human cells using fluorogenic and replenishable nanobody array fusions of the dCas9, and compact polycistronic single guide (sg)RNAs.
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