Rational optimization of reprogramming culture conditions for the generation of induced pluripotent stem cells with ultra-high efficiency and fast kinetics

• DOI: 10.1038/cr.2011.51
• Publication Date: 2011-03-29T10:39:30Z
• Authors: Jiekai Chen; Jing Liu; You Chen; Jiaqi Yang; Jing Chen; He Liu; Xiangjie Zhao; Kunlun Mo; Hong Song; Lin Guo; Shilong Chu; Deping Wang; Ke Ding; Duanqing Pei
• Keywords: 0301 basic medicine; Mice, Inbred ICR; Time Factors; SOXB1 Transcription Factors; Genetic Vectors; Induced Pluripotent Stem Cells; Cell Culture Techniques; Kruppel-Like Transcription Factors; Cell Dedifferentiation; Fibroblasts; Transfection; Coculture Techniques; Recombinant Proteins; Culture Media; Kruppel-Like Factor 4; Mice; 03 medical and health sciences; Retroviridae; Karyotyping; Animals; Octamer Transcription Factor-3; Cell Proliferation

The ectopic expression of several transcription factors can restore embryonic cell fate to cultured somatic cells and generate induced pluripotent stem cells (iPSCs), revealing a previously unknown pathway to pluripotency. However, this technology is currently limited by low efficiency, slow kinetics and multi-factorial requirement. Here we show that reprogramming can be improved and dramatically accelerated by optimizing culture conditions. First, we developed an optimized defined medium, iCD1, which allows Oct4/Sox2/Klf4 (OSK)-mediated reprogramming to achieve ultra-high efficiency (~10% at day 8). We also found that this optimized condition renders both Sox2 and Klf4 dispensable, although the elimination of these two factors leads to lower efficiency and slower kinetics. Our studies define a shortened route, both in timing and factor requirement, toward pluripotency. This new paradigm not only provides a rationale to further improve iPSC generation but also simplifies the conceptual understanding of reprogramming by defined factors.