A New Age in Regenerative Medicine

Kyoto, Japan -

In a recent paper Takahashi K et al. Induction of Pluripotent Stem Cells from Adult Human Fibroblasts by Defined Factors.Cell. 2007 Nov 20 generation of an "inducible pluripotent stem cell" or iPS from human skin was announced.

Here is a video describing the paper

Essentially the researchers obtained human dermal fibroblasts and transfected them with the "stemness" factors Oct-3/4 and Sox-2, as well as with the chromatin/DNA methylation modifiers Klf-4 and c-myc. After retroviral introduction of these proteins into the cells, the transfection cells were plated on feeders and FGF, and after about a month clumps of cells that morphologically resembled embryonic stem cells were seen.

The iPS cells expressed similar immunohistochemical staining profiles as ES cells (Nanog, SSEA, TRA etc), as well as gene expression and protein expression profiles. Ability to form embryoid bodies, as well as pluripotent differentiation was demonstrated at a similar ability of the iPS cells as ES cells. Teratoma formation was also demonstrated.

This study seems to demonstrate for the first time the ability to retrodifferentiate an adult cell using distinct factors. Next steps in this research will be to replicate this without the need for protein transduction or retroviruses. If this could be performed, then indeed we will be standing at the dawn of a new age in regenerative medicine.