• Proceedings of the KSAR Conference
• /
• 2001.03a
• /
• pp.49-49
• /
• 2001

To elucidate overall changes in DNA methylation that occurs by inappropriate epigenetic control during ageing, we compared fetal bovine fibroblasts and their aged neomycin-resistant versions using bisulfite-PCR technology. Reduction in DNA methylation was observed in euchromatic repeats (18S-rRNA/art2) and promoter regions of sing1e-copy genes (the cytokeratin/-lactoglobulin/interleukin-13 genes). Contrastingly, a stable maintenance of DNA methylation was revealed in various heterochromatic sequences (satellite I/IIalphoid and Bov-B). The differential inheritance modes of DNA methylation was confirmed through the analysis of individual neomycin-resistant clones. These global, multi-loci analyses provide evidence on the tendency of differential epigenetic modification between genomic DNA regions during ageing.

• Molecules and Cells
• /
• v.46 no.2
• /
• pp.86-98
• /
• 2023

The genome is almost identical in all the cells of the body. However, the functions and morphologies of each cell are different, and the factors that determine them are the genes and proteins expressed in the cells. Over the past decades, studies on epigenetic information, such as DNA methylation, histone modifications, chromatin accessibility, and chromatin conformation have shown that these properties play a fundamental role in gene regulation. Furthermore, various diseases such as cancer have been found to be associated with epigenetic mechanisms. In this study, we summarized the biological properties of epigenetics and single-cell epigenomic profiling techniques, and discussed future challenges in the field of epigenetics.

• Korean Journal of Plant Tissue Culture
• /
• v.27 no.5
• /
• pp.359-366
• /
• 2000

Epigenetics represents a chromatin-mediated transcriptional repression which plays a control role in both animal and plant development. A number of different mechanisms have been described to be involved in the formation of chromatin structure: especially DNA methylation, nucleosomal histone modification, DNA replication timing, and binding of chromatin remodelling proteins. Epigenetic phenomena include genomic imprinting, dosage compensation of X-chromosome linked genes, mutual allelic interactions, paramutation, transvection, silencing of invasive DNA sequences, etc. They are often unstable and inherited in a non-Mendelian way. A number of epigenetic defects has been preferentially described in floral development. Here, epigenetic phenomena in model angiosperm plants and their corresponding mechanisms are reviewed.

• Molecules and Cells
• /
• v.40 no.1
• /
• pp.10-16
• /
• 2017

When peripheral axons are damaged, neuronal injury signaling pathways induce transcriptional changes that support axon regeneration and consequent functional recovery. The recent development of bioinformatics techniques has allowed for the identification of many of the regeneration-associated genes that are regulated by neural injury, yet it remains unclear how global changes in transcriptome are coordinated. In this article, we review recent studies on the epigenetic mechanisms orchestrating changes in gene expression in response to nerve injury. We highlight the importance of epigenetic mechanisms in discriminating efficient axon regeneration in the peripheral nervous system and very limited axon regrowth in the central nervous system and discuss the therapeutic potential of targeting epigenetic regulators to improve neural recovery.

• BMB Reports
• /
• v.43 no.12
• /
• pp.830-835
• /
• 2010

Epigenetic modification of the genome through DNA methylation is the key to maintaining the differentiated state of human embryonic stem cells (hESCs), and it must be reset during differentiation by retinoic acid (RA) treatment. A genome-wide methylation/gene expression assay was performed in order to identify epigenetic modifications of RA-treated hESCs. Between undifferentiated and RA-treated hESCs, 166 differentially methylated CpG sites and 2,013 differentially expressed genes were discovered. Combined analysis of methylation and expression data revealed that 19 genes (STAP2, VAMP8, C10orf26, WFIKKN1, ELF3, C1QTNF6, C10orf10, MRGPRF, ARSE, LSAMP, CENTD3, LDB2, POU5F1, GSPT2, THY1, ZNF574, MSX1, SCMH1, and RARB) were highly correlated with each other. The results provided in this study will facilitate future investigations into the interplay between DNA methylation and gene expression through further functional and biological studies.

• International Journal of Stem Cells
• /
• v.16 no.2
• /
• pp.156-167
• /
• 2023

Background and Objectives: Cellular reprogramming in regenerative medicine holds great promise for treating patients with neurological disorders. In this regard, small molecule-mediated cellular conversion has attracted special attention because of its ease of reproducibility, applicability, and fewer safety concerns. However, currently available protocols for the direct conversion of somatic cells to neurons are limited in clinical application due of their complex nature, lengthy process, and low conversion efficiency. Methods and Results: Here, we report a new protocol involving chemical-based direct conversion of human fibroblasts (HF) to matured neuron-like cells with a short duration and high conversion efficiency using temporal and strategic dual epigenetic regulation. In this protocol, epigenetic modulation by inhibition of histone deacetylase and bromodomain enabled to overcome "recalcitrant" nature of adult fibroblasts and shorten the duration of neuronal reprogramming. We further observed that an extended epigenetic regulation is necessary to maintain the induced neuronal program to generate a homogenous population of neuron-like cells. Conclusions: Therefore, our study provides a new protocol to produce neurons-like cells and highlights the need of proper epigenetic resetting to establish and maintain neuronal program in HF.

• BMB Reports
• /
• v.40 no.2
• /
• pp.135-141
• /
• 2007

Conjugation of the methyl group at the fifth carbon of cytosines within the palindromic dinucleotide 5'-CpG-3' sequence (DNA methylation) is the best studied epigenetic mechanism, which acts together with other epigenetic entities: histone modification, chromatin remodeling and microRNAs to shape the chromatin structure of DNA according to its functional state. The cancer genome is frequently characterized by hypermethylation of specific genes concurrently with an overall decrease in the level of 5-methyl cytosine, the pathological implication of which to the cancerous state has been well established. While the latest genome-wide technologies have been applied to classify and interpret the epigenetic layer of gene regulation in the physiological and disease states, the epigenetic testing has also been seriously explored in clinical practice for early detection, refining tumor staging and predicting disease recurrence. This critique reviews the latest research findings on the use of DNA methylation in cancer diagnosis, prognosis and staging/classification.

• Journal of Korean Medicine Rehabilitation
• /
• v.30 no.1
• /
• pp.63-78
• /
• 2020

Objectives To review the epigenetic modifications involved in chronic pain and to improve individualized intervention for the chronic pain. Methods Focused literature review. Results Significant laboratory and clinical data support that epigenetic modifications have a potential role for development of chronic pain. Conclusions Epigenetic approach may identify mechanisms critical to the development of chronic pain after injury, and may provide new pathways and target mechanisms for future treatment and individualized medicine.

• Development and Reproduction
• /
• v.15 no.4
• /
• pp.273-279
• /
• 2011

Epigenetic regulation is a phenomenon that changes the gene function without changing the underlying DNA sequences. Epigenetic status of chromosome is regulated by mechanisms such as histone modification, DNA modification, and RNAi silencing. In this review, we focused on histone methylation for epigenetic regulation in ES cells. Two antagonizing multiprotein complexes regulate methylation of histones to guide expression of genes in ES cells. The Polycomb repressive complex 2 (PRC2), including EED, EZH2, and SUZ12 as core factors, contributes to gene repression by increasing trimethylation of H3K27 (H3K27me3). In contrast, the Trithorax group (TrxG) complex including MLL is related to gene activation by making H3K4me3. PRC2 and TrxG accompany a variety of accessory proteins. Most prominent feature of epigenetic regulation in ES cells is a bivalent state in which H3K27me3 and H3K4me3 appear simultaneously. Concerted regulation of PRC2, TrxG complex, and H3K4- or H3K27-specific demethylases activate expression of pluripotency-related genes and suppress development-related genes in ES cells. Modified balance of the regulators also enables ES cells to efficiently differentiate to a variety of cells upon differentiating signals. More detailed insights on the epigenetic regulators and their action will lead us to better understanding and use of ES cells for future application.

• Restorative Dentistry and Endodontics
• /
• v.40 no.1
• /
• pp.14-22
• /
• 2015

Genetic information such as DNA sequences has been limited to fully explain mechanisms of gene regulation and disease process. Epigenetic mechanisms, which include DNA methylation, histone modification and non-coding RNAs, can regulate gene expression and affect progression of disease. Although studies focused on epigenetics are being actively investigated in the field of medicine and biology, epigenetics in dental research is at the early stages. However, studies on epigenetics in dentistry deserve attention because epigenetic mechanisms play important roles in gene expression during tooth development and may affect oral diseases. In addition, understanding of epigenetic alteration is important for developing new therapeutic methods. This review article aims to outline the general features of epigenetic mechanisms and describe its future implications in the field of dentistry.