15 April 2016
C/EBPα creates elite cells for iPSC reprogramming by upregulating Klf4 and increasing the levels of Lsd1 and Brd4.
Di Stefano, Bruno*, Samuel Collombet*, Janus Schou Jakobsen*, Michael Wierer, Jose Luis Sardina, Andreas Lackner, Ralph Stadhouders, Carolina Segura-Morales, Mirko Francesconi, Francesco Limone, Matthias Mann, Bo Porse, Denis Thieffry & Thomas Graf (2016). C/EBPα creates elite cells for iPSC reprogramming by upregulating Klf4 and increasing the levels of Lsd1 and Brd4. Nature Cell Biology, 18(4), 371-381, doi:10.1038/ncb3326.
* These authors contributed equally
Reprogramming somatic cells into induced pluripotent stem cells (iPSCs) is typically inefficient and has been explained by elite-cell and stochastic models. We recently reported that B cells exposed to a pulse of C/EBPα (Bα′ cells) behave as elite cells, in that they can be rapidly and efficiently reprogrammed into iPSCs by the Yamanaka factors OSKM. Here we show that C/EBPα post-transcriptionally increases the abundance of several hundred proteins, including Lsd1, Hdac1, Brd4, Med1 and Cdk9, components of chromatin-modifying complexes present at super-enhancers. Lsd1 was found to be required for B cell gene silencing and Brd4 for the activation of the pluripotency program. C/EBPα also promotes chromatin accessibility in pluripotent cells and upregulates Klf4 by binding to two haematopoietic enhancers. Bα′ cells share many properties with granulocyte/macrophage progenitors, naturally occurring elite cells that are obligate targets for leukaemic transformation, whose formation strictly requires C/EBPα.