Bypassing the iPS logjam
Researchers atthe Stanford University School of Medicinehave found a way to efficiently convert mouse fibroblasts into functional neurons without first reverting the skin cells to a pluripotent state.1 The protocol could make it possible to use host-derived fibroblasts to create neurons for disease modeling, drug screening and transplantation studies.
The conventional approach to turning fibroblasts into a different cell type involves reprogramming the skin cells into induced pluripotent stem (iPS) cells using a quartet of transcription factors (Oct4, Sox2, Klf4 and c-Myc).2,3 TheiPS cells are then isolated, expanded and differentiated into a new cell type. However, the efficiency of the process is low and the procedure can take months.
The Stanford protocol skips the pluripotent step altogether and in doing so gains efficiency and speed (see "Generating neurons from fibroblasts").
In mouse fibroblasts, forced expression of three transcription factors-achaete-scute