Open AccessPhysiological Oxygen Prevents Frequent Silencing of the DLK1‐DIO3 Cluster during Human Embryonic Stem Cells Culture
Author(s) -
Xie Pingyuan,
Sun Yi,
Ouyang Qi,
Hu Liang,
Tan Yueqiu,
Zhou Xiaoying,
Xiong Bo,
Zhang Qianjun,
Yuan Ding,
Pan Yi,
Liu Tiancheng,
Liang Ping,
Lu Guangxiu,
Lin Ge
Publication year - 2014
Publication title -
stem cells
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.159
H-Index - 229
eISSN - 1549-4918
pISSN - 1066-5099
DOI - 10.1002/stem.1558
Subject(s) - biology , epigenetics , embryonic stem cell , gene silencing , stem cell , dna methylation , microbiology and biotechnology , embryo , cellular differentiation , gene expression , methylation , cell culture , gene , genetics
Genetic and epigenetic alterations are observed in long‐term culture (>30 passages) of human embryonic stem cells (hESCs); however, little information is available in early cultures. Through a large‐scale gene expression analysis between initial‐passage hESCs (ihESCs, <10 passages) and early‐passage hESCs (ehESCs, 20–30 passages) of 12 hESC lines, we found that the DLK1‐DIO3 gene cluster was normally expressed and showed normal methylation pattern in ihESC, but was frequently silenced after 20 passages. Both the DLK1‐DIO3 active status in ihESCs and the inactive status in ehESCs were inheritable during differentiation. Silencing of the DLK1‐DIO3 cluster did not seem to compromise the multilineage differentiation ability of hESCs, but was associated with reduced DNA damage‐induced apoptosis in ehESCs and their differentiated hepatocyte‐like cell derivatives, possibly through attenuation of the expression and phosphorylation of p53. Furthermore, we demonstrated that 5% oxygen, instead of the commonly used 20% oxygen, is required for preserving the expression of the DLK1‐DIO3 cluster. Overall, the data suggest that active expression of the DLK1‐DIO3 cluster represents a new biomarker for epigenetic stability of hESCs and indicates the importance of using a proper physiological oxygen level during the derivation and culture of hESCs. S tem C ells 2014;32:391–401