title: Regulation of apoptosis and differentiation by p53 in human embryonic stem cells.
abstract: The essentially infinite expansion potential and pluripotency of human embryonic stem cells (hESCs) makes them attractive for cell-based therapeutics. In contrast to mouse embryonic stem cells (mESCs), hESCs normally undergo high rates of spontaneous apoptosis and differentiation, making them difficult to maintain in culture. Here we demonstrate that p53 protein accumulates in apoptotic hESCs induced by agents that damage DNA. However, despite the accumulation of p53, it nevertheless fails to activate the transcription of its target genes. This inability of p53 to activate its target genes has not been observed in other cell types, including mESCs. We further demonstrate that p53 induces apoptosis of hESCs through a mitochondrial pathway. Reducing p53 expression in hESCs in turn reduces both DNA damage-induced apoptosis as well as spontaneous apoptosis. Reducing p53 expression also reduces spontaneous differentiation and slows the differentiation rate of hESCs. Our studies reveal the important roles of p53 as a critical mediator of human embryonic stem cells survival and differentiation.
authors.affiliation: Key Laboratory of Cell Proliferation and Differentiation of the Ministry of Education, College of Life Sciences, Peking University, Yiheyuan Road 5, Beijing 100871, China.
authors.forename: Han
authors.initials: H
authors.lastname: Qin
authors.forename: Tianxin
authors.initials: T
authors.lastname: Yu
authors.forename: Tingting
authors.initials: T
authors.lastname: Qing
authors.forename: Yanxia
authors.initials: Y
authors.lastname: Liu
authors.forename: Yang
authors.initials: Y
authors.lastname: Zhao
authors.forename: Jun
authors.initials: J
authors.lastname: Cai
authors.forename: Jian
authors.initials: J
authors.lastname: Li
authors.forename: Zhihua
authors.initials: Z
authors.lastname: Song
authors.forename: Xiuxia
authors.initials: X
authors.lastname: Qu
authors.forename: Peng
authors.initials: P
authors.lastname: Zhou
authors.forename: Jiong
authors.initials: J
authors.lastname: Wu
authors.forename: Mingxiao
authors.initials: M
authors.lastname: Ding
authors.forename: Hongkui
authors.initials: H
authors.lastname: Deng
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000502:physiology*; D002454:Cell Differentiation / Q000502:physiology*; D002478:Cells, Cultured; D004249:DNA Damage; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology*; D006801:Humans; D051379:Mice; D008928:Mitochondria / Q000378:metabolism; D016159:Tumor Suppressor Protein p53 / Q000096:biosynthesis*
chemical_list: D016159:Tumor Suppressor Protein p53