Previously, we found that the delivery of mouse ES (mES) cell-derived proteins to adult fibroblasts enables the full reprogramming of these cells, converting them to mouse pluripotent stem cells (protein-iPS cells) without transduction of defined factors. During reprogramming, global gene expression and epigenetic status such as DNA methylation and histone modifications convert from somatic to ES-equivalent status. mES cell extract-derived iPS cells are biologically and functionally indistinguishable from mES cells in its potential in differentiation both invitro and invivo. Furthermore, these cells show complete developmental potency. However, the efficiency of generating iPS by treatment with extract from mES cells is still low. In this report, we demonstrated that protein extracts of mouse iPS cells that were previously generated by mES cell extract treatment were able to reprogram somatic cells to become ES-like cells (secondary protein-iPS cells). We confirmed that fetal animals (E12.5) could be derived from these cells. Surprisingly, the efficiency of forming Oct4-positive colonies was remarkably improved by treatment of somatic cells with mouse iPS cell extract in comparison to treatment with mES cell extract. By screening the genes differentially expressed between mouse iPS and mES cells, Zscan4, which is known to enhance telomere elongation and stabilize genomic DNA, was identified as a strong candidate to promote efficiency of reprogramming. Interestingly, treatment with protein extracted from mES cells overexpressing Zscan4 enhanced formation of Oct4-positive colonies. Our results provide an efficient and safe strategy for reprogramming somatic cells by using mouse iPS cell extract. Zscan4 might be a key molecule involved in the demonstrated improvement of reprogramming efficiency.
|Number of pages||14|
|State||Published - 1 Aug 2015|
Bibliographical noteFunding Information:
We thank Yeon-Ju Chung and Min-Jung Je for technical assistance. This study was supported by a grant from the Innovative Research Institute for Cell Therapy ( A062260 ) and supported by the Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Korean government ( 2010-0020258 ).
© 2015 Elsevier Ltd.
- Efficient iPSC generation method
- IPSC extract
- Secondary derived iPSC