Differential regulation of OCT4 targets facilitates reacquisition of pluripotency

• Published in: Nature communications Vol. 10; no. 1; pp. 4444 - 11
• Main Authors: Thakurela, Sudhir, Sindhu, Camille, Yurkovsky, Evgeny, Riemenschneider, Christina, Smith, Zachary D., Nachman, Iftach, Meissner, Alexander
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 30.09.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 13; 13/100; 38; 38/91; 45/100; 45/15; 631/136/2444; 631/532; 631/532/1360; 631/532/2435; Animals; Cell differentiation; Cell Differentiation - physiology; Cell Line; Cellular Reprogramming - physiology; Efficiency; Fibroblasts; Gene Expression Regulation; Genomics; Humanities and Social Sciences; Induced Pluripotent Stem Cells - metabolism; Kinetics; Mice; Molecular modelling; multidisciplinary; Nanog Homeobox Protein; Oct-4 protein; Octamer Transcription Factor-3 - genetics; Octamer Transcription Factor-3 - metabolism; Pluripotency; Reaction kinetics; Regulatory sequences; Science; Science (multidisciplinary); Somatic cells; Stem Cells; Transcription factors; Transcription Factors - metabolism
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-11741-5

Ectopic transcription factor expression enables reprogramming of somatic cells to pluripotency, albeit with generally low efficiency. Despite steady progress in the field, the exact molecular mechanisms that coordinate this remarkable transition still remain largely elusive. To better characterize the final steps of pluripotency induction, we optimized an experimental system where pluripotent stem cells are differentiated for set intervals before being reintroduced to pluripotency-supporting conditions. Using this approach, we identify a transient period of high-efficiency reprogramming where ectopic transcription factors, but not serum/LIF alone, rapidly revert cells to pluripotency with near 100% efficiency. After this period, cells reprogram with somatic-like kinetics and efficiencies. We identify a set of OCT4 bound cis -regulatory elements that are dynamically regulated during this transient phase and appear central to facilitating reprogramming. Interestingly, these regions remain hypomethylated during in vitro and in vivo differentiation, which may allow them to act as primary targets of ectopically induced factors during somatic cell reprogramming. Barriers underlying the inefficiency of reprogramming cells to pluripotency are poorly defined. Here the authors identify a transient interval soon after pluripotency exit that permits high-efficiency reprogramming and is facilitated by OCT4 bound elements displaying unique silencing behaviour during differentiation.