Important phenomenon has been discovered by scientists from GIBH in the field of iPSCs

Recently, the research group led by Prof Duanqing Pei and Dr Jiekai Chen has discovered that H3K9 methylation is a barrier during somatic cell reprogramming into iPSCs.

In this study, Prof Pei and Dr Chen demonstrated that there is an epigenetic barrier--H3K9 methylation, blocking conversation from somatic cells to induced pluripotent stem cells. Firstly, they found that serum could inhibit reprogramming at a named "pre-iPSC" state. BMPs signaling was then proved as the major inhibitor in the serum. Mechanistically, BMPs signaling regulates H3K9 methylation on important pluripotent loci via Setdb1, leading to an inaccessible state of these loci towards Oct4 regulation. Vitamin C could stimulate further reprogramming from pre-iPSCs to iPSCs by activating H3K9 demethylases. These results give some insights into the mechanism of incomplete reprogramming, and also show an important crosstalk between signaling transduction and epigenetic regulation during cell fate determination. 

Their work has been published in top tier journal Nature Genetics in December 2012.