Stem Cells Reprogrammed Using Own Genes
Adult skin cells can be reprogrammed into embryonic-like induced pluripotent stem cells, as Nobel laureate Shinya Yamanaka discovered over ten years ago. Up till now, however, reprogramming has only been possible by introducing the critical genes for the conversion, called Yamanaka factors, artificially into skin cells where they are not normally active at all.
Professor Timo Otonkoski at the University of Helsinki and Professor Juha Kere at Karolinska Institutet and King’s College London, with their teams of researchers, have now for the first time succeeded in converting skin cells into pluripotent stem cells by activating the cell’s own genes. This was achieved by using gene editing technology—known as CRISPR—that can be directed to activate genes. The method utilises a blunted version of the Cas9 “gene scissors” that does not cut DNA and can therefore be used to activate gene expression without mutating the genome.
The technique is, theoretically, a more physiological way of controlling cell fate and may result in more normal cells, according to Professor Otonkoski. “Using this technology, pluripotent stem cells were obtained that resembled very closely typical early embryonal cells,” Professor Kere says.
The discovery also suggests that it might be possible to improve many other reprogramming tasks by addressing genetic elements typical of the intended target cell type. In addition, the study opens up new insights into the mechanisms controlling early embryonic gene activation.
Science Daily. July 6. Nature Communications. July 6.