Despite recent successes in cloning various mammals and amphibians, the low efficiency of animals production and abnormal symptoms in many cloned animals are crucial problems in cloning technology. To overcome these problems, scientists focus on mechanisms of cloning. A possible cause of the low success frequency of cloning is the insufficient dedifferentiation and the inadequate reprogramming of the high differentiated adult somatic nucleus in enucleated oocytes, which caused by incomplete methylation and premature de novo remethylation of donor DNA. In cloned embryos the methylation level is higher than normal embryos, and this may cause aberrant expression of several important genes, especially imprinting genes. Study on these mechanisms is very important to improve the rate of successful cloned animals.
Animals ; Cloning, Organism ; DNA Methylation ; genetics ; physiology ; Epigenesis, Genetic ; genetics ; physiology ; Genomic Imprinting ; genetics ; physiology ; Humans

This study investigated the effect of epigenetic modification of maspin on extravillous trophoblastic function. The mRNA expression of maspin in placentae from normotensive and preeclamptic pregnant women was detected by RT-PCR. TEV-1 cells, a human first-trimester extravillous trophoblast cell line, were cultured and treated with CoCl(2) (300 μmol/L) to induce chemical hypoxia and with 5-aza (500 nmol/L) to induce demethylation. The mRNA expression of maspin in TEV-1 cells subjected to different treatments was determined by RT-PCR, and the proliferative and migratory abilities of TEV-1 cells were assessed by cell counting kit-8 (CCK-8) and Transwell assays. Our results showed that the maspin mRNA expression level in placentae from preeclamptic women was much higher than that from normotensive women. CoCl(2) or 5-aza could up-regulate the mRNA expression of maspin and significantly suppress the proliferation and migration of TEV-1 cells. It was concluded that the epigenetic modification in promoter region of maspin contributes to incomplete trophoblast invasion, which offers a novel approach for predicting and treating placental dysfunction.
Adult ; Chorionic Villi ; physiology ; Epigenesis, Genetic ; genetics ; Female ; Humans ; Pregnancy ; Serpins ; genetics ; Trophoblasts ; physiology

In eukaryotic cells, histones are packaged into octameric core particles with DNA wrapping around to form nucleosomes, which are the basic units of chromatin (Kornberg and Thomas, 1974). Multicellular organisms utilise chromatin marks to translate one single genome into hundreds of epigenomes for their corresponding cell types. Inheritance of epigenetic status is critical for the maintenance of gene expression profile during mitotic cell divisions (Allis et al., 2006). During S phase, canonical histones are deposited onto DNA in a replication-coupled manner (Allis et al., 2006). To understand how dividing cells overcome the dilution of epigenetic marks after chromatin duplication, DNA replication coupled (RC) nucleosome assembly has been of great interest. In this review, we focus on the potential influence of RC nucleosome assembly processes on the maintenance of epigenetic status.
Animals ; Chromatin Assembly and Disassembly ; genetics ; physiology ; DNA Replication ; Epigenesis, Genetic ; Histones ; chemistry ; physiology ; Humans ; Nucleosomes ; genetics ; physiology ; Protein Structure, Quaternary

Animals ; Epigenesis, Genetic ; genetics ; Fetal Development ; genetics ; physiology ; Glucose ; metabolism ; Humans ; MicroRNAs ; genetics ; metabolism

The developmental program of T helper and regulatory T cell lineage commitment is governed by both genetic and epigenetic mechanisms. The principal events, signaling pathways and the lineage determining factors involved have been extensively studied in the past ten years. Recent studies have elucidated the important role of chromatin remodeling and epigenetic changes for proper regulation of gene expression of lineage-specific cytokines. These include DNA methylation and histone modifications in epigenomic reprogramming during T helper cell development and effector T cell functions. This review discusses the basic epigenetic mechanisms and the role of transcription factors for the differential cytokine gene regulation in the T helper lymphocyte subsets.
Animals ; Cytokines/metabolism ; Epigenesis, Genetic/*genetics ; Gene Expression Regulation/genetics/physiology ; Humans ; T-Lymphocytes/*metabolism

DNA Replication ; Epigenesis, Genetic ; Hepatitis B virus ; genetics ; physiology ; Virus Replication

Epigenetic factors play an important role in male infertility though about 60%－65% of the disease is idiopathic and its underlying causes are not yet clear. Many studies have indicated that epigenetic modifications, including DNA methylation, histone tail modifications, chromatin remodeling, and non-coding RNAs, may be involved in idiopathic male infertility. Abnormal methylation is associated with decreased sperm quality and fertility. It is known that 1 881 miRNAs are related to male fertility and such non-coding RNAs as piRNA, IncRNA, and circRNA play a regulating role in male reproduction. This review focuses on the value of epigenetics in the etiology and pathogenesis of male infertility, aiming to provide some evidence for the establishment of some strategies for the treatment and prediction of the disease.
DNA Methylation ; Epigenesis, Genetic ; Fertility ; Humans ; Infertility, Male ; genetics ; Male ; MicroRNAs ; physiology ; RNA, Small Interfering ; Spermatozoa

Long noncoding RNA (lncRNA) is once thought to be the genome transcriptional "noise". However, it has received considerable attention in the past few years and is emerging as potentially important player in biological regulation. Recent studies have revealed that increasing number of lncRNA plays pivotal roles in regulating the gene expression which involves in the development of the human disease. Functions of lncRNA include 3 types of interaction: RNA-RNA, RNA-DNA, and RNA-protein, which may participate in gene expression regulation through epigenetic modifications, transcriptional regulation, post-transcriptional regulation, acting as biological media. Due to the prevalence of obesity and related diseases, some attempts have been done to explore the pathogenesis of obesity from the field of noncoding RNA. Several lncRNAs have been identified to be involved in the regulation of the adipogenesis (white adipose tissue and brown adipose tissue) and energy metabolism. In this review, we summarized recent advances of lncRNAs to provide a new sight for the mechanism of obesity.
Adipogenesis ; genetics ; Epigenesis, Genetic ; Gene Expression Regulation ; Humans ; RNA, Long Noncoding ; physiology ; RNA, Untranslated

DNA methylation, histone modifications, and the chromatin structure are profoundly altered in human cancers. The silencing of cancer-related genes by these epigenetic regulators is recognized as a key mechanism in tumor formation. Recent findings revealed that DNA methylation and histone modifications appear to be linked to each other. However, it is not clearly understood how the formation of histone modifications may affect DNA methylation and which genes are relevantly involved with tumor formation. The presence of histone modifications does not always link to DNA methylation in human cancers, which suggests that another factor is required to connect these two epigenetic mechanisms. In this review, examples of studies that demonstrated the relationship between histone modifications and DNA methylation in human cancers are presented and the potential implications of these epigenetic mechanisms in human neoplasia are discussed.
DNA Methylation/*physiology ; Epigenesis, Genetic/*physiology ; Histone-Lysine N-Methyltransferase/metabolism ; Histones/*metabolism ; Humans ; Models, Biological ; Neoplasms/*genetics

DNA methylation, histone modifications, and the chromatin structure are profoundly altered in human cancers. The silencing of cancer-related genes by these epigenetic regulators is recognized as a key mechanism in tumor formation. Recent findings revealed that DNA methylation and histone modifications appear to be linked to each other. However, it is not clearly understood how the formation of histone modifications may affect DNA methylation and which genes are relevantly involved with tumor formation. The presence of histone modifications does not always link to DNA methylation in human cancers, which suggests that another factor is required to connect these two epigenetic mechanisms. In this review, examples of studies that demonstrated the relationship between histone modifications and DNA methylation in human cancers are presented and the potential implications of these epigenetic mechanisms in human neoplasia are discussed.
DNA Methylation/*physiology ; Epigenesis, Genetic/*physiology ; Histone-Lysine N-Methyltransferase/metabolism ; Histones/*metabolism ; Humans ; Models, Biological ; Neoplasms/*genetics