Gene transcription and new protein synthesis regulated by epigenetics play integral roles in the formation of new memories. However, as an important part of epigenetics, the function of chromatin remodeling in learning and memory has been less studied. Here, we showed that SMARCA5 (SWI/SNF related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 5), a critical chromatin remodeler, was responsible for hippocampus-dependent memory maintenance and neurogenesis. Using proteomics analysis, we found protein expression changes in the hippocampal dentate gyrus (DG) after the knockdown of SMARCA5 during contextual fear conditioning (CFC) memory maintenance in mice. Moreover, SMARCA5 was revealed to participate in CFC memory maintenance via modulating the proteins of metabolic pathways such as nucleoside diphosphate kinase-3 (NME3) and aminoacylase 1 (ACY1). This work is the first to describe the role of SMARCA5 in memory maintenance and to demonstrate the involvement of metabolic pathways regulated by SMARCA5 in learning and memory.
Mice ; Animals ; Memory ; Chromatin Assembly and Disassembly ; Hippocampus/metabolism* ; Transcription Factors/metabolism* ; Chromatin/metabolism* ; Metabolic Networks and Pathways

Eukaryotic DNA is hierarchically packaged into chromatin to fit inside the nucleus. Dynamics of the chromatin structure plays a critical role in transcriptional regulation and other biological processes that involve DNA, such as DNA replication and DNA repair. Many factors, including histone variants, histone modification, DNA methylation and the binding of non-histone architectural proteins regulate the structure of chromatin. Although the structure of nucleosomes, the fundamental repeating unit of chromatin, is clear, there is still much discussion on the higher-order levels of chromatin structure. Identifying the structural details and dynamics of higher-order chromatin fibers is therefore very important for understanding the organization and regulation of gene activities. Here, we review studies on the dynamics of chromatin higher order structure and its relationship with gene transcription.
Animals ; Chromatin ; chemistry ; metabolism ; Chromatin Assembly and Disassembly ; Eukaryotic Cells ; chemistry ; metabolism ; Gene Expression Regulation ; Humans ; Models, Molecular

Epigenetic alterations are associated with all aspects of cancer, from tumor initiation to cancer progression and metastasis. It is now well understood that both losses and gains of DNA methylation as well as altered chromatin organization contribute significantly to cancer-associated phenotypes. More recently, new sequencing technologies have allowed the identification of driver mutations in epigenetic regulators, providing a mechanistic link between the cancer epigenome and genetic alterations. Oncogenic activating mutations are now known to occur in a number of epigenetic modifiers (i.e. IDH1/2, EZH2, DNMT3A), pinpointing epigenetic pathways that are involved in tumorigenesis. Similarly, investigations into the role of inactivating mutations in chromatin modifiers (i.e. KDM6A, CREBBP/EP300, SMARCB1) implicate many of these genes as tumor suppressors. Intriguingly, a number of neoplasms are defined by a plethora of mutations in epigenetic regulators, including renal, bladder, and adenoid cystic carcinomas. Particularly striking is the discovery of frequent histone H3.3 mutations in pediatric glioma, a particularly aggressive neoplasm that has long remained poorly understood. Cancer epigenetics is a relatively new, promising frontier with much potential for improving cancer outcomes. Already, therapies such as 5-azacytidine and decitabine have proven that targeting epigenetic alterations in cancer can lead to tangible benefits. Understanding how genetic alterations give rise to the cancer epigenome will offer new possibilities for developing better prognostic and therapeutic strategies.
Chromatin ; metabolism ; Chromatin Assembly and Disassembly ; DNA Methylation ; Enhancer of Zeste Homolog 2 Protein ; Epigenesis, Genetic ; Histones ; metabolism ; Humans ; Neoplasms ; genetics ; metabolism ; pathology ; Polycomb Repressive Complex 2 ; genetics ; metabolism

Metabolic syndrome has become a global epidemic that adversely affects human health. Both genetic and environmental factors contribute to the pathogenesis of metabolic disorders; however, the mechanisms that integrate these cues to regulate metabolic physiology and the development of metabolic disorders remain incompletely defined. Emerging evidence suggests that SWI/SNF chromatin-remodeling complexes are critical for directing metabolic reprogramming and adaptation in response to nutritional and other physiological signals. The ATP-dependent SWI/SNF chromatin-remodeling complexes comprise up to 11 subunits, among which the BAF60 subunit serves as a key link between the core complexes and specific transcriptional factors. The BAF60 subunit has three members, BAF60a, b, and c. The distinct tissue distribution patterns and regulatory mechanisms of BAF60 proteins confer each isoform with specialized functions in different metabolic cell types. In this review, we summarize the emerging roles and mechanisms of BAF60 proteins in the regulation of nutrient sensing and energy metabolism under physiological and disease conditions.
Chromatin Assembly and Disassembly ; DNA-Binding Proteins ; metabolism ; Disease ; Humans ; Metabolism ; Nutrients ; metabolism ; Signal Transduction

Adenosine/metabolism* ; Animals ; Chromatin/metabolism* ; DNA Transposable Elements ; Epigenesis, Genetic ; RNA, Messenger/metabolism*

Understanding the regulatory networks for germ cell fate specification is necessary to developing strategies for improving the efficiency of germ cell production in vitro. In this study, we developed a coupled screening strategy that took advantage of an arrayed bi-molecular fluorescence complementation (BiFC) platform for protein-protein interaction screens and epiblast-like cell (EpiLC)-induction assays using reporter mouse embryonic stem cells (mESCs). Investigation of candidate interaction partners of core human pluripotent factors OCT4, NANOG, KLF4 and SOX2 in EpiLC differentiation assays identified novel primordial germ cell (PGC)-inducing factors including BEN-domain (BEND/Bend) family members. Through RNA-seq, ChIP-seq, and ATAC-seq analyses, we showed that Bend5 worked together with Bend4 and helped mark chromatin boundaries to promote EpiLC induction in vitro. Our findings suggest that BEND/Bend proteins represent a new family of transcriptional modulators and chromatin boundary factors that participate in gene expression regulation during early germline development.
Animals ; Cell Differentiation/genetics* ; Chromatin/metabolism* ; Embryonic Stem Cells ; Germ Cells/metabolism* ; Germ Layers/metabolism* ; Mice

METTL3 and METTL14 are two components that form the core heterodimer of the main RNA m6A methyltransferase complex (MTC) that installs m6A. Surprisingly, depletion of METTL3 or METTL14 displayed distinct effects on stemness maintenance of mouse embryonic stem cell (mESC). While comparable global hypo-methylation in RNA m6A was observed in Mettl3 or Mettl14 knockout mESCs, respectively. Mettl14 knockout led to a globally decreased nascent RNA synthesis, whereas Mettl3 depletion resulted in transcription upregulation, suggesting that METTL14 might possess an m6A-independent role in gene regulation. We found that METTL14 colocalizes with the repressive H3K27me3 modification. Mechanistically, METTL14, but not METTL3, binds H3K27me3 and recruits KDM6B to induce H3K27me3 demethylation independent of METTL3. Depletion of METTL14 thus led to a global increase in H3K27me3 level along with a global gene suppression. The effects of METTL14 on regulation of H3K27me3 is essential for the transition from self-renewal to differentiation of mESCs. This work reveals a regulatory mechanism on heterochromatin by METTL14 in a manner distinct from METTL3 and independently of m6A, and critically impacts transcriptional regulation, stemness maintenance, and differentiation of mESCs.
Animals ; Mice ; Methylation ; Chromatin ; Histones/metabolism* ; RNA, Messenger/genetics* ; Methyltransferases/metabolism* ; RNA/metabolism*

OBJECTIVETo identify the effects of overtraining on human sperm DNA.

METHODSMolecular epidemiological investigation of 249 men from different groups (training and non-training) was carried out by using flow cytometer to detect the integrity and damage of in situ DNA of sperm nucleus, and sperm chromatin structure assay was performed.

RESULTSThe average COMPalpha(t) in training group was 11.02% while that in control group was 5.90% (P < 0.01). COMPalpha(t) was significantly correlated with sperm activity (r = 0.41, P < 0.05).

CONCLUSIONOvertraining could induce sperm DNA injury and affect sperm activity, thus to decrease the potentiality of reproduction.

Adult ; Chromatin ; genetics ; metabolism ; DNA Fragmentation ; Exercise ; physiology ; Humans ; Male ; Sperm Motility ; physiology ; Spermatozoa ; cytology ; metabolism

Recent applications of new tools for genome-wide mapping of long-range and spatial interactions have shed light onto the fundamental mechanisms of three dimensional chromatin organizations in pluripotent stem cells and their derivatives.
Animals ; Cell Differentiation ; Chromatin ; genetics ; metabolism ; Epigenesis, Genetic ; Genome, Human ; Humans ; Pluripotent Stem Cells ; metabolism

Chromatin ; genetics ; metabolism ; Epigenesis, Genetic ; Genomic Instability ; Histones ; metabolism ; Humans ; Neoplasms ; metabolism ; pathology ; Ubiquitin-Protein Ligases ; genetics ; metabolism