Epigenetics of pluripotent cells.
Pluripotency is maintained by a complex system that includes the genetic and epigenetic levels. Recent studies have shown that the genetic level (transcription factors, signal pathways, and microRNAs) closely interacts with the enzymes and other specific proteins that participate in the formation of the chromatin structure. The interaction between the two systems results in the unique chromatin state observed in pluripotent cells. In this review, the epigenetic features of embryonic stem cells and induced pluripotent stem cells are considered. Special attention is paid to the interplay of the transcription factors OCT4, SOX2, and NANOG with the Polycomb group proteins and other molecules involved in the regulation of the chromatin structure. The participation of the transcription factors of the pluripotency system in the inactivation of the X chromosome is discussed. In addition, the epigenetic events taking place during reprogramming of somatic cells to the pluripotent state and the problem of "epigenetic memory" are considered.
Institute of Cytology and Genetics, Siberian Branch, Russian Academy of Sciences, Prospekt Lavrentyeva, 10, Novosibirsk, Russia, 630090 ; Meshalkin Novosibirsk State Research Institute of Circulation Pathology, Rechkunovskaja Str., 15, Novosibirsk, Russia, 630055 ; Institute of Chemical Biology and Fundamental Medicine, Siberian Branch, Russian Academy of Sciences, Prospekt Lavrentyeva, 8, Novosibirsk, Russia, 630090.
S P
SP
Medvedev
E A
EA
Pokushalov
S M
SM
Zakian
DNA methylation; covalent histone modifications; embryonic stem cells; induced pluripotent stem cells; pluripotency