title: Serum starvation induced cell cycle synchronization facilitates human somatic cells reprogramming.
abstract: Human induced pluripotent stem cells (iPSCs) provide a valuable model for regenerative medicine and human disease research. To date, however, the reprogramming efficiency of human adult cells is still low. Recent studies have revealed that cell cycle is a key parameter driving epigenetic reprogramming to pluripotency. As is well known, retroviruses such as the Moloney murine leukemia virus (MoMLV) require cell division to integrate into the host genome and replicate, whereas the target primary cells for reprogramming are a mixture of several cell types with different cell cycle rhythms. Whether cell cycle synchronization has potential effect on retrovirus induced reprogramming has not been detailed. In this study, utilizing transient serum starvation induced synchronization, we demonstrated that starvation generated a reversible cell cycle arrest and synchronously progressed through G2/M phase after release, substantially improving retroviral infection efficiency. Interestingly, synchronized human dermal fibroblasts (HDF) and adipose stem cells (ASC) exhibited more homogenous epithelial morphology than normal FBS control after infection, and the expression of epithelial markers such as E-cadherin and Epcam were strongly activated. Futhermore, synchronization treatment ultimately improved Nanog positive clones, achieved a 15-20 fold increase. These results suggested that cell cycle synchronization promotes the mesenchymal to epithelial transition (MET) and facilitates retrovirus mediated reprogramming. Our study, utilization of serum starvation rather than additional chemicals, provide a new insight into cell cycle regulation and induced reprogramming of human cells.
authors.affiliation: State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, Guangdong, China.
authors.forename: Mengfei
authors.initials: M
authors.lastname: Chen
authors.forename: Jingjing
authors.initials: J
authors.lastname: Huang
authors.forename: Xuejiao
authors.initials: X
authors.lastname: Yang
authors.forename: Bingqian
authors.initials: B
authors.lastname: Liu
authors.forename: Weizhong
authors.initials: W
authors.lastname: Zhang
authors.forename: Li
authors.initials: L
authors.lastname: Huang
authors.forename: Fei
authors.initials: F
authors.lastname: Deng
authors.forename: Jian
authors.initials: J
authors.lastname: Ma
authors.forename: Yujing
authors.initials: Y
authors.lastname: Bai
authors.forename: Rong
authors.initials: R
authors.lastname: Lu
authors.forename: Bing
authors.initials: B
authors.lastname: Huang
authors.forename: Qianying
authors.initials: Q
authors.lastname: Gao
authors.forename: Yehong
authors.initials: Y
authors.lastname: Zhuo
authors.forename: Jian
authors.initials: J
authors.lastname: Ge
mesh_terms: D002453:Cell Cycle / Q000502:physiology*; D002454:Cell Differentiation; D065150:Cellular Reprogramming / Q000502:physiology*; D016895:Culture Media, Serum-Free; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology* / Q000378:metabolism*; D014161:Transduction, Genetic
chemical_list: D016895:Culture Media, Serum-Free