Chinese researchers report on a new paradigm to improve the production of induced pluripotent stem cells in the Journal of Cell Research.

Induced pluripotent stem cells offer researchers the opportunity to understand the regulation of cell fate determination at the biochemical, molecular and cellular levels. However, until now low efficiency, slow kinetics and multifactorial requirements have created bottle necks in the process.

In the current study Duanqing Pei and colleagues, from the Chinese Academy of Sciences (Guangzhou, China), investigated the various ways of inducing pluripotency through the introduction of a rational method of optimization in mouse embryonic fibroblasts.

First, the team started the optimization process by building a "positive" library of compounds and growth factors through a screening process for their ability to support or inhibit Oct4/Sox2/Klf4 (OKS)-mediated reprogramming in a standard culture medium. Compounds or growth factors showing inhibitory effects were eliminated.

Next they identified CHIR99021, liCl, 2-phospho-L-ascorbic acid, vitamin B12 and thiamine as critical small chemical components of the optimized medium. The rapid and robust reprogramming was then confirmed at the molecular level by analyzing the expression of pluripotent markers including Nanog, endogenous Oct4, and Dppa3.

The induced pluripotent stem cell approach, write the authors, offers a great opportunity to understand the epigenetic regulation of cell fate determination at the biochemical, molecular and cellular levels triggered by reprogramming factors. "We believe that this reprogramming system can be used as an ideal platform for investigating the individual contribution of medium supplements and reprogramming factors," they conclude.

Article: J Chen, J Liu, Y Chen. Rational optimization of reprogramming culture conditions for the generation of induced pluripotent stem cells with ultra-high efficiency and fast kinetics. Cell Research. Doi: 10.1038/cr.2011.51